^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0-only
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) * Framework for buffer objects that can be shared across devices/subsystems.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright(C) 2011 Linaro Limited. All rights reserved.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Author: Sumit Semwal <sumit.semwal@ti.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Many thanks to linaro-mm-sig list, and specially
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * Arnd Bergmann <arnd@arndb.de>, Rob Clark <rob@ti.com> and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) * Daniel Vetter <daniel@ffwll.ch> for their support in creation and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * refining of this idea.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/dma-buf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/dma-fence.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/anon_inodes.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/export.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/debugfs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) #include <linux/seq_file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #include <linux/sync_file.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) #include <linux/poll.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) #include <linux/dma-resv.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) #include <linux/mount.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) #include <linux/pseudo_fs.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) #include <linux/sched/task.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) #include <uapi/linux/dma-buf.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) #include <uapi/linux/magic.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) #include "dma-buf-sysfs-stats.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) struct dma_buf_list {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) struct list_head head;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) struct mutex lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) static struct dma_buf_list db_list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) * This function helps in traversing the db_list and calls the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) * callback function which can extract required info out of each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) * dmabuf.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) int get_each_dmabuf(int (*callback)(const struct dma_buf *dmabuf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) void *private), void *private)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) struct dma_buf *buf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) int ret = mutex_lock_interruptible(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) list_for_each_entry(buf, &db_list.head, list_node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) ret = callback(buf, private);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) mutex_unlock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) EXPORT_SYMBOL_GPL(get_each_dmabuf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) #if IS_ENABLED(CONFIG_DMABUF_DEBUG)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) static size_t db_total_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) static size_t db_peak_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) void dma_buf_reset_peak_size(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) mutex_lock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) db_peak_size = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) mutex_unlock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) EXPORT_SYMBOL_GPL(dma_buf_reset_peak_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) size_t dma_buf_get_peak_size(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) size_t sz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) mutex_lock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) sz = db_peak_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) mutex_unlock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) return sz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89) EXPORT_SYMBOL_GPL(dma_buf_get_peak_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) size_t dma_buf_get_total_size(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) size_t sz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) mutex_lock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) sz = db_total_size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) mutex_unlock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) return sz;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) EXPORT_SYMBOL_GPL(dma_buf_get_total_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) struct dma_buf *dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) char name[DMA_BUF_NAME_LEN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) size_t ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) dmabuf = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) spin_lock(&dmabuf->name_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) if (dmabuf->name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113) ret = strlcpy(name, dmabuf->name, DMA_BUF_NAME_LEN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) spin_unlock(&dmabuf->name_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) return dynamic_dname(dentry, buffer, buflen, "/%s:%s",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) dentry->d_name.name, ret > 0 ? name : "");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) static void dma_buf_release(struct dentry *dentry)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) struct dma_buf *dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) #ifdef CONFIG_NO_GKI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) int dtor_ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) dmabuf = dentry->d_fsdata;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) if (unlikely(!dmabuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) BUG_ON(dmabuf->vmapping_counter);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) * Any fences that a dma-buf poll can wait on should be signaled
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) * before releasing dma-buf. This is the responsibility of each
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) * driver that uses the reservation objects.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) * If you hit this BUG() it means someone dropped their ref to the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) * dma-buf while still having pending operation to the buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) dma_buf_stats_teardown(dmabuf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) #ifdef CONFIG_NO_GKI
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) if (dmabuf->dtor)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) dtor_ret = dmabuf->dtor(dmabuf, dmabuf->dtor_data);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) if (!dtor_ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) dmabuf->ops->release(dmabuf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) if (dmabuf->resv == (struct dma_resv *)&dmabuf[1])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) dma_resv_fini(dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) WARN_ON(!list_empty(&dmabuf->attachments));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) module_put(dmabuf->owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) kfree(dmabuf->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) kfree(dmabuf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) static int dma_buf_file_release(struct inode *inode, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) struct dma_buf *dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) if (!is_dma_buf_file(file))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) dmabuf = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170) mutex_lock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) #if IS_ENABLED(CONFIG_DMABUF_DEBUG)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) db_total_size -= dmabuf->size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) list_del(&dmabuf->list_node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175) mutex_unlock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) static const struct dentry_operations dma_buf_dentry_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) .d_dname = dmabuffs_dname,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) .d_release = dma_buf_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) static struct vfsmount *dma_buf_mnt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) static int dma_buf_fs_init_context(struct fs_context *fc)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) struct pseudo_fs_context *ctx;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) ctx = init_pseudo(fc, DMA_BUF_MAGIC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 192) if (!ctx)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 193) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 194) ctx->dops = &dma_buf_dentry_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 195) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 196) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 197)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 198) static struct file_system_type dma_buf_fs_type = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 199) .name = "dmabuf",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 200) .init_fs_context = dma_buf_fs_init_context,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 201) .kill_sb = kill_anon_super,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 202) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 203)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 204) static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 205) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 206) struct dma_buf *dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 207)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 208) if (!is_dma_buf_file(file))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 209) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 210)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 211) dmabuf = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 213) /* check if buffer supports mmap */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 214) if (!dmabuf->ops->mmap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 215) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 216)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 217) /* check for overflowing the buffer's size */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 218) if (vma->vm_pgoff + vma_pages(vma) >
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 219) dmabuf->size >> PAGE_SHIFT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 220) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 222) return dmabuf->ops->mmap(dmabuf, vma);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 223) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 224)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 225) static loff_t dma_buf_llseek(struct file *file, loff_t offset, int whence)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 226) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 227) struct dma_buf *dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 228) loff_t base;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 229)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 230) if (!is_dma_buf_file(file))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 231) return -EBADF;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 232)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 233) dmabuf = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 234)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 235) /* only support discovering the end of the buffer,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 236) but also allow SEEK_SET to maintain the idiomatic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 237) SEEK_END(0), SEEK_CUR(0) pattern */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 238) if (whence == SEEK_END)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 239) base = dmabuf->size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 240) else if (whence == SEEK_SET)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 241) base = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 242) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 243) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 244)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 245) if (offset != 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 246) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 247)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 248) return base + offset;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 249) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 250)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 251) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 252) * DOC: implicit fence polling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 253) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 254) * To support cross-device and cross-driver synchronization of buffer access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 255) * implicit fences (represented internally in the kernel with &struct dma_fence)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 256) * can be attached to a &dma_buf. The glue for that and a few related things are
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 257) * provided in the &dma_resv structure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 258) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 259) * Userspace can query the state of these implicitly tracked fences using poll()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 260) * and related system calls:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 261) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 262) * - Checking for EPOLLIN, i.e. read access, can be use to query the state of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 263) * most recent write or exclusive fence.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 264) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 265) * - Checking for EPOLLOUT, i.e. write access, can be used to query the state of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 266) * all attached fences, shared and exclusive ones.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 267) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 268) * Note that this only signals the completion of the respective fences, i.e. the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 269) * DMA transfers are complete. Cache flushing and any other necessary
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 270) * preparations before CPU access can begin still need to happen.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 271) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 272) * As an alternative to poll(), the set of fences on DMA buffer can be
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 273) * exported as a &sync_file using &dma_buf_sync_file_export.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 274) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 275)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 276) static void dma_buf_poll_cb(struct dma_fence *fence, struct dma_fence_cb *cb)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 277) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 278) struct dma_buf_poll_cb_t *dcb = (struct dma_buf_poll_cb_t *)cb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 279) unsigned long flags;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 280)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 281) spin_lock_irqsave(&dcb->poll->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 282) wake_up_locked_poll(dcb->poll, dcb->active);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 283) dcb->active = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 284) spin_unlock_irqrestore(&dcb->poll->lock, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 285) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 286)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 287) static __poll_t dma_buf_poll(struct file *file, poll_table *poll)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 288) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 289) struct dma_buf *dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 290) struct dma_resv *resv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 291) struct dma_resv_list *fobj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 292) struct dma_fence *fence_excl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 293) __poll_t events;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 294) unsigned shared_count, seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 295)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 296) dmabuf = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 297) if (!dmabuf || !dmabuf->resv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 298) return EPOLLERR;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 299)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 300) resv = dmabuf->resv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 301)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 302) poll_wait(file, &dmabuf->poll, poll);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 303)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 304) events = poll_requested_events(poll) & (EPOLLIN | EPOLLOUT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 305) if (!events)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 306) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 307)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 308) retry:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 309) seq = read_seqcount_begin(&resv->seq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 310) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 311)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 312) fobj = rcu_dereference(resv->fence);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 313) if (fobj)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 314) shared_count = fobj->shared_count;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 315) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 316) shared_count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 317) fence_excl = rcu_dereference(resv->fence_excl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 318) if (read_seqcount_retry(&resv->seq, seq)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 319) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 320) goto retry;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 321) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 322)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 323) if (fence_excl && (!(events & EPOLLOUT) || shared_count == 0)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 324) struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_excl;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 325) __poll_t pevents = EPOLLIN;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 326)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 327) if (shared_count == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 328) pevents |= EPOLLOUT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 329)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 330) spin_lock_irq(&dmabuf->poll.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 331) if (dcb->active) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 332) dcb->active |= pevents;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 333) events &= ~pevents;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 334) } else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 335) dcb->active = pevents;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 336) spin_unlock_irq(&dmabuf->poll.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 337)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 338) if (events & pevents) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 339) if (!dma_fence_get_rcu(fence_excl)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 340) /* force a recheck */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 341) events &= ~pevents;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 342) dma_buf_poll_cb(NULL, &dcb->cb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 343) } else if (!dma_fence_add_callback(fence_excl, &dcb->cb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 344) dma_buf_poll_cb)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 345) events &= ~pevents;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 346) dma_fence_put(fence_excl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 347) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 348) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 349) * No callback queued, wake up any additional
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 350) * waiters.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 351) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 352) dma_fence_put(fence_excl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 353) dma_buf_poll_cb(NULL, &dcb->cb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 354) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 355) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 356) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 357)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 358) if ((events & EPOLLOUT) && shared_count > 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 359) struct dma_buf_poll_cb_t *dcb = &dmabuf->cb_shared;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 360) int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 361)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 362) /* Only queue a new callback if no event has fired yet */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 363) spin_lock_irq(&dmabuf->poll.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 364) if (dcb->active)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 365) events &= ~EPOLLOUT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 366) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 367) dcb->active = EPOLLOUT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 368) spin_unlock_irq(&dmabuf->poll.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 370) if (!(events & EPOLLOUT))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 371) goto out;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 373) for (i = 0; i < shared_count; ++i) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 374) struct dma_fence *fence = rcu_dereference(fobj->shared[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 375)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 376) if (!dma_fence_get_rcu(fence)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 377) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 378) * fence refcount dropped to zero, this means
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 379) * that fobj has been freed
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 380) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 381) * call dma_buf_poll_cb and force a recheck!
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 382) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 383) events &= ~EPOLLOUT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 384) dma_buf_poll_cb(NULL, &dcb->cb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 385) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 386) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 387) if (!dma_fence_add_callback(fence, &dcb->cb,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 388) dma_buf_poll_cb)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 389) dma_fence_put(fence);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 390) events &= ~EPOLLOUT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 391) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 392) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 393) dma_fence_put(fence);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 394) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 396) /* No callback queued, wake up any additional waiters. */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 397) if (i == shared_count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 398) dma_buf_poll_cb(NULL, &dcb->cb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 399) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 400)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 401) out:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 402) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 403) return events;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 404) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 405)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 406) static long _dma_buf_set_name(struct dma_buf *dmabuf, const char *name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 407) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 408) spin_lock(&dmabuf->name_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 409) kfree(dmabuf->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 410) dmabuf->name = name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 411) spin_unlock(&dmabuf->name_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 412)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 413) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 414) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 415)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 416) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 417) * dma_buf_set_name - Set a name to a specific dma_buf to track the usage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 418) * It could support changing the name of the dma-buf if the same piece of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 419) * memory is used for multiple purpose between different devices.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 420) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 421) * @dmabuf: [in] dmabuf buffer that will be renamed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 422) * @buf: [in] A piece of userspace memory that contains the name of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 423) * the dma-buf.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 424) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 425) * Returns 0 on success. If the dma-buf buffer is already attached to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 426) * devices, return -EBUSY.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 427) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 428) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 429) long dma_buf_set_name(struct dma_buf *dmabuf, const char *name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 430) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 431) long ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 432) char *buf = kstrndup(name, DMA_BUF_NAME_LEN, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 433)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 434) if (!buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 435) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 436)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 437) ret = _dma_buf_set_name(dmabuf, buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 438) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 439) kfree(buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 440)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 441) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 442) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 443) EXPORT_SYMBOL_GPL(dma_buf_set_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 444)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 445) static long dma_buf_set_name_user(struct dma_buf *dmabuf, const char __user *buf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 446) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 447) char *name = strndup_user(buf, DMA_BUF_NAME_LEN);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 448) long ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 449)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 450) if (IS_ERR(name))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 451) return PTR_ERR(name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 452)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 453) ret = _dma_buf_set_name(dmabuf, name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 454) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 455) kfree(name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 456)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 457) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 458) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 459)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 460) #if IS_ENABLED(CONFIG_SYNC_FILE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 461) static long dma_buf_export_sync_file(struct dma_buf *dmabuf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 462) void __user *user_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 463) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 464) struct dma_buf_export_sync_file arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 465) struct dma_fence *fence = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 466) struct sync_file *sync_file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 467) bool write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 468) int fd, ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 469)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 470) if (copy_from_user(&arg, user_data, sizeof(arg)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 471) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 472)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 473) if (arg.flags & ~DMA_BUF_SYNC_RW)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 474) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 475)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 476) if ((arg.flags & DMA_BUF_SYNC_RW) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 477) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 478)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 479) fd = get_unused_fd_flags(O_CLOEXEC);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 480) if (fd < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 481) return fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 482)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 483) write = (arg.flags & DMA_BUF_SYNC_WRITE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 484) ret = dma_resv_get_singleton(dmabuf->resv, write, &fence);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 485) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 486) goto err_put_fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 487)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 488) if (!fence)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 489) fence = dma_fence_get_stub();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 490)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 491) sync_file = sync_file_create(fence);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 492)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 493) dma_fence_put(fence);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 494)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 495) if (!sync_file) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 496) ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 497) goto err_put_fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 498) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 499)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 500) arg.fd = fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 501) if (copy_to_user(user_data, &arg, sizeof(arg))) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 502) ret = -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 503) goto err_put_file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 504) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 505)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 506) fd_install(fd, sync_file->file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 507)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 508) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 509)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 510) err_put_file:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 511) fput(sync_file->file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 512) err_put_fd:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 513) put_unused_fd(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 514) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 515) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 516)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 517) static long dma_buf_import_sync_file(struct dma_buf *dmabuf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 518) const void __user *user_data)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 519) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 520) struct dma_buf_import_sync_file arg;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 521) struct dma_fence *fence;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 522) bool write;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 523) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 524)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 525) if (copy_from_user(&arg, user_data, sizeof(arg)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 526) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 527)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 528) if (arg.flags & ~DMA_BUF_SYNC_RW)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 529) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 530)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 531) if ((arg.flags & DMA_BUF_SYNC_RW) == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 532) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 533)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 534) fence = sync_file_get_fence(arg.fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 535) if (!fence)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 536) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 537)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 538) write = (arg.flags & DMA_BUF_SYNC_WRITE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 539)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 540) dma_resv_lock(dmabuf->resv, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 541)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 542) if (write) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 543) dma_resv_add_excl_fence(dmabuf->resv, fence);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 544) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 545) ret = dma_resv_reserve_shared(dmabuf->resv, 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 546) if (!ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 547) dma_resv_add_shared_fence(dmabuf->resv, fence);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 548) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 549)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 550) dma_resv_unlock(dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 551)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 552) dma_fence_put(fence);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 553)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 554) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 555) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 556) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 557)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 558) static long dma_buf_ioctl(struct file *file,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 559) unsigned int cmd, unsigned long arg)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 560) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 561) struct dma_buf *dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 562) struct dma_buf_sync sync;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 563) struct dma_buf_sync_partial sync_p;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 564) enum dma_data_direction direction;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 565) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 566)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 567) dmabuf = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 568)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 569) switch (cmd) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 570) case DMA_BUF_IOCTL_SYNC:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 571) if (copy_from_user(&sync, (void __user *) arg, sizeof(sync)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 572) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 573)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 574) if (sync.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 575) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 576)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 577) switch (sync.flags & DMA_BUF_SYNC_RW) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 578) case DMA_BUF_SYNC_READ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 579) direction = DMA_FROM_DEVICE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 580) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 581) case DMA_BUF_SYNC_WRITE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 582) direction = DMA_TO_DEVICE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 583) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 584) case DMA_BUF_SYNC_RW:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 585) direction = DMA_BIDIRECTIONAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 586) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 587) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 588) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 589) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 590)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 591) if (sync.flags & DMA_BUF_SYNC_END)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 592) ret = dma_buf_end_cpu_access(dmabuf, direction);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 593) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 594) ret = dma_buf_begin_cpu_access(dmabuf, direction);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 595)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 596) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 597)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 598) case DMA_BUF_SET_NAME_A:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 599) case DMA_BUF_SET_NAME_B:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 600) return dma_buf_set_name_user(dmabuf, (const char __user *)arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 602) case DMA_BUF_IOCTL_SYNC_PARTIAL:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 603) if (copy_from_user(&sync_p, (void __user *) arg, sizeof(sync_p)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 604) return -EFAULT;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 605)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 606) if (sync_p.len == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 607) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 608)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 609) if (sync_p.len > dmabuf->size || sync_p.offset > dmabuf->size - sync_p.len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 610) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 611)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 612) if (sync_p.flags & ~DMA_BUF_SYNC_VALID_FLAGS_MASK)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 613) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 614)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 615) switch (sync_p.flags & DMA_BUF_SYNC_RW) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 616) case DMA_BUF_SYNC_READ:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 617) direction = DMA_FROM_DEVICE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 618) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 619) case DMA_BUF_SYNC_WRITE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 620) direction = DMA_TO_DEVICE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 621) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 622) case DMA_BUF_SYNC_RW:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 623) direction = DMA_BIDIRECTIONAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 624) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 625) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 626) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 627) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 628)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 629) if (sync_p.flags & DMA_BUF_SYNC_END)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 630) ret = dma_buf_end_cpu_access_partial(dmabuf, direction,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 631) sync_p.offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 632) sync_p.len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 633) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 634) ret = dma_buf_begin_cpu_access_partial(dmabuf, direction,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 635) sync_p.offset,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 636) sync_p.len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 637)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 638) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 639)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 640) #if IS_ENABLED(CONFIG_SYNC_FILE)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 641) case DMA_BUF_IOCTL_EXPORT_SYNC_FILE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 642) return dma_buf_export_sync_file(dmabuf, (void __user *)arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 643) case DMA_BUF_IOCTL_IMPORT_SYNC_FILE:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 644) return dma_buf_import_sync_file(dmabuf, (const void __user *)arg);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 645) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 646)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 647) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 648) return -ENOTTY;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 649) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 650) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 651)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 652) static void dma_buf_show_fdinfo(struct seq_file *m, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 653) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 654) struct dma_buf *dmabuf = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 655)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 656) seq_printf(m, "size:\t%zu\n", dmabuf->size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 657) /* Don't count the temporary reference taken inside procfs seq_show */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 658) seq_printf(m, "count:\t%ld\n", file_count(dmabuf->file) - 1);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 659) seq_printf(m, "exp_name:\t%s\n", dmabuf->exp_name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 660) spin_lock(&dmabuf->name_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 661) if (dmabuf->name)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 662) seq_printf(m, "name:\t%s\n", dmabuf->name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 663) spin_unlock(&dmabuf->name_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 664) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 665)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 666) static const struct file_operations dma_buf_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 667) .release = dma_buf_file_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 668) .mmap = dma_buf_mmap_internal,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 669) .llseek = dma_buf_llseek,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 670) .poll = dma_buf_poll,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 671) .unlocked_ioctl = dma_buf_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 672) .compat_ioctl = compat_ptr_ioctl,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 673) .show_fdinfo = dma_buf_show_fdinfo,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 674) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 675)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 676) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 677) * is_dma_buf_file - Check if struct file* is associated with dma_buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 678) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 679) int is_dma_buf_file(struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 680) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 681) return file->f_op == &dma_buf_fops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 682) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 683) EXPORT_SYMBOL_GPL(is_dma_buf_file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 684)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 685) static struct file *dma_buf_getfile(struct dma_buf *dmabuf, int flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 686) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 687) struct file *file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 688) struct inode *inode = alloc_anon_inode(dma_buf_mnt->mnt_sb);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 689)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 690) if (IS_ERR(inode))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 691) return ERR_CAST(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 692)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 693) inode->i_size = dmabuf->size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 694) inode_set_bytes(inode, dmabuf->size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 695)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 696) file = alloc_file_pseudo(inode, dma_buf_mnt, "dmabuf",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 697) flags, &dma_buf_fops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 698) if (IS_ERR(file))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 699) goto err_alloc_file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 700) file->f_flags = flags & (O_ACCMODE | O_NONBLOCK);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 701) file->private_data = dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 702) file->f_path.dentry->d_fsdata = dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 703)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 704) return file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 705)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 706) err_alloc_file:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 707) iput(inode);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 708) return file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 709) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 710)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 711) static void dma_buf_set_default_name(struct dma_buf *dmabuf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 712) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 713) char task_comm[TASK_COMM_LEN];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 714) char *name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 715)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 716) get_task_comm(task_comm, current->group_leader);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 717) name = kasprintf(GFP_KERNEL, "%d-%s", current->tgid, task_comm);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 718) dma_buf_set_name(dmabuf, name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 719) kfree(name);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 720) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 721)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 722) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 723) * DOC: dma buf device access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 724) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 725) * For device DMA access to a shared DMA buffer the usual sequence of operations
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 726) * is fairly simple:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 727) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 728) * 1. The exporter defines his exporter instance using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 729) * DEFINE_DMA_BUF_EXPORT_INFO() and calls dma_buf_export() to wrap a private
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 730) * buffer object into a &dma_buf. It then exports that &dma_buf to userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 731) * as a file descriptor by calling dma_buf_fd().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 732) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 733) * 2. Userspace passes this file-descriptors to all drivers it wants this buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 734) * to share with: First the filedescriptor is converted to a &dma_buf using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 735) * dma_buf_get(). Then the buffer is attached to the device using
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 736) * dma_buf_attach().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 737) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 738) * Up to this stage the exporter is still free to migrate or reallocate the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 739) * backing storage.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 740) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 741) * 3. Once the buffer is attached to all devices userspace can initiate DMA
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 742) * access to the shared buffer. In the kernel this is done by calling
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 743) * dma_buf_map_attachment() and dma_buf_unmap_attachment().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 744) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 745) * 4. Once a driver is done with a shared buffer it needs to call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 746) * dma_buf_detach() (after cleaning up any mappings) and then release the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 747) * reference acquired with dma_buf_get by calling dma_buf_put().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 748) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 749) * For the detailed semantics exporters are expected to implement see
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 750) * &dma_buf_ops.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 751) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 752)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 753) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 754) * dma_buf_export - Creates a new dma_buf, and associates an anon file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 755) * with this buffer, so it can be exported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 756) * Also connect the allocator specific data and ops to the buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 757) * Additionally, provide a name string for exporter; useful in debugging.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 758) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 759) * @exp_info: [in] holds all the export related information provided
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 760) * by the exporter. see &struct dma_buf_export_info
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 761) * for further details.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 762) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 763) * Returns, on success, a newly created dma_buf object, which wraps the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 764) * supplied private data and operations for dma_buf_ops. On either missing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 765) * ops, or error in allocating struct dma_buf, will return negative error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 766) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 767) * For most cases the easiest way to create @exp_info is through the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 768) * %DEFINE_DMA_BUF_EXPORT_INFO macro.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 769) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 770) struct dma_buf *dma_buf_export(const struct dma_buf_export_info *exp_info)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 771) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 772) struct dma_buf *dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 773) struct dma_resv *resv = exp_info->resv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 774) struct file *file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 775) size_t alloc_size = sizeof(struct dma_buf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 776) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 777)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 778) if (!exp_info->resv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 779) alloc_size += sizeof(struct dma_resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 780) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 781) /* prevent &dma_buf[1] == dma_buf->resv */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 782) alloc_size += 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 783)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 784) if (WARN_ON(!exp_info->priv
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 785) || !exp_info->ops
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 786) || !exp_info->ops->map_dma_buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 787) || !exp_info->ops->unmap_dma_buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 788) || !exp_info->ops->release)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 789) return ERR_PTR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 790) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 791)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 792) if (WARN_ON(exp_info->ops->cache_sgt_mapping &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 793) (exp_info->ops->pin || exp_info->ops->unpin)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 794) return ERR_PTR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 795)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 796) if (WARN_ON(!exp_info->ops->pin != !exp_info->ops->unpin))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 797) return ERR_PTR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 798)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 799) if (!try_module_get(exp_info->owner))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 800) return ERR_PTR(-ENOENT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 801)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 802) dmabuf = kzalloc(alloc_size, GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 803) if (!dmabuf) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 804) ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 805) goto err_module;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 806) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 807)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 808) dmabuf->priv = exp_info->priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 809) dmabuf->ops = exp_info->ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 810) dmabuf->size = exp_info->size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 811) dmabuf->exp_name = exp_info->exp_name;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 812) dmabuf->owner = exp_info->owner;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 813) spin_lock_init(&dmabuf->name_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 814) init_waitqueue_head(&dmabuf->poll);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 815) dmabuf->cb_excl.poll = dmabuf->cb_shared.poll = &dmabuf->poll;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 816) dmabuf->cb_excl.active = dmabuf->cb_shared.active = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 817)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 818) if (!resv) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 819) resv = (struct dma_resv *)&dmabuf[1];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 820) dma_resv_init(resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 821) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 822) dmabuf->resv = resv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 823)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 824) file = dma_buf_getfile(dmabuf, exp_info->flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 825) if (IS_ERR(file)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 826) ret = PTR_ERR(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 827) goto err_dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 828) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 829)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 830) file->f_mode |= FMODE_LSEEK;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 831) dmabuf->file = file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 832)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 833) mutex_init(&dmabuf->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 834) INIT_LIST_HEAD(&dmabuf->attachments);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 835)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 836) mutex_lock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 837) list_add(&dmabuf->list_node, &db_list.head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 838) #if IS_ENABLED(CONFIG_DMABUF_DEBUG)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 839) db_total_size += dmabuf->size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 840) db_peak_size = max(db_total_size, db_peak_size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 841) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 842) mutex_unlock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 843)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 844) ret = dma_buf_stats_setup(dmabuf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 845) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 846) goto err_sysfs;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 847)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 848) if (IS_ENABLED(CONFIG_DMABUF_DEBUG))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 849) dma_buf_set_default_name(dmabuf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 850)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 851) return dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 852)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 853) err_sysfs:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 854) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 855) * Set file->f_path.dentry->d_fsdata to NULL so that when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 856) * dma_buf_release() gets invoked by dentry_ops, it exits
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 857) * early before calling the release() dma_buf op.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 858) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 859) file->f_path.dentry->d_fsdata = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 860) fput(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 861) err_dmabuf:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 862) kfree(dmabuf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 863) err_module:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 864) module_put(exp_info->owner);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 865) return ERR_PTR(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 866) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 867) EXPORT_SYMBOL_GPL(dma_buf_export);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 868)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 869) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 870) * dma_buf_fd - returns a file descriptor for the given dma_buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 871) * @dmabuf: [in] pointer to dma_buf for which fd is required.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 872) * @flags: [in] flags to give to fd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 873) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 874) * On success, returns an associated 'fd'. Else, returns error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 875) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 876) int dma_buf_fd(struct dma_buf *dmabuf, int flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 877) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 878) int fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 879)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 880) if (!dmabuf || !dmabuf->file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 881) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 882)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 883) fd = get_unused_fd_flags(flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 884) if (fd < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 885) return fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 886)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 887) fd_install(fd, dmabuf->file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 888)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 889) return fd;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 890) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 891) EXPORT_SYMBOL_GPL(dma_buf_fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 892)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 893) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 894) * dma_buf_get - returns the dma_buf structure related to an fd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 895) * @fd: [in] fd associated with the dma_buf to be returned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 896) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 897) * On success, returns the dma_buf structure associated with an fd; uses
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 898) * file's refcounting done by fget to increase refcount. returns ERR_PTR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 899) * otherwise.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 900) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 901) struct dma_buf *dma_buf_get(int fd)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 902) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 903) struct file *file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 904)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 905) file = fget(fd);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 906)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 907) if (!file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 908) return ERR_PTR(-EBADF);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 909)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 910) if (!is_dma_buf_file(file)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 911) fput(file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 912) return ERR_PTR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 913) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 914)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 915) return file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 916) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 917) EXPORT_SYMBOL_GPL(dma_buf_get);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 918)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 919) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 920) * dma_buf_put - decreases refcount of the buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 921) * @dmabuf: [in] buffer to reduce refcount of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 922) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 923) * Uses file's refcounting done implicitly by fput().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 924) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 925) * If, as a result of this call, the refcount becomes 0, the 'release' file
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 926) * operation related to this fd is called. It calls &dma_buf_ops.release vfunc
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 927) * in turn, and frees the memory allocated for dmabuf when exported.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 928) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 929) void dma_buf_put(struct dma_buf *dmabuf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 930) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 931) if (WARN_ON(!dmabuf || !dmabuf->file))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 932) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 933)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 934) fput(dmabuf->file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 935) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 936) EXPORT_SYMBOL_GPL(dma_buf_put);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 937)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 938) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 939) * dma_buf_dynamic_attach - Add the device to dma_buf's attachments list; optionally,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 940) * calls attach() of dma_buf_ops to allow device-specific attach functionality
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 941) * @dmabuf: [in] buffer to attach device to.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 942) * @dev: [in] device to be attached.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 943) * @importer_ops: [in] importer operations for the attachment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 944) * @importer_priv: [in] importer private pointer for the attachment
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 945) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 946) * Returns struct dma_buf_attachment pointer for this attachment. Attachments
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 947) * must be cleaned up by calling dma_buf_detach().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 948) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 949) * Returns:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 950) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 951) * A pointer to newly created &dma_buf_attachment on success, or a negative
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 952) * error code wrapped into a pointer on failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 953) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 954) * Note that this can fail if the backing storage of @dmabuf is in a place not
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 955) * accessible to @dev, and cannot be moved to a more suitable place. This is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 956) * indicated with the error code -EBUSY.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 957) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 958) struct dma_buf_attachment *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 959) dma_buf_dynamic_attach(struct dma_buf *dmabuf, struct device *dev,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 960) const struct dma_buf_attach_ops *importer_ops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 961) void *importer_priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 962) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 963) struct dma_buf_attachment *attach;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 964) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 965)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 966) if (WARN_ON(!dmabuf || !dev))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 967) return ERR_PTR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 968)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 969) if (WARN_ON(importer_ops && !importer_ops->move_notify))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 970) return ERR_PTR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 971)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 972) attach = kzalloc(sizeof(*attach), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 973) if (!attach)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 974) return ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 975)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 976) attach->dev = dev;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 977) attach->dmabuf = dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 978) if (importer_ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 979) attach->peer2peer = importer_ops->allow_peer2peer;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 980) attach->importer_ops = importer_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 981) attach->importer_priv = importer_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 982)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 983) if (dmabuf->ops->attach) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 984) ret = dmabuf->ops->attach(dmabuf, attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 985) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 986) goto err_attach;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 987) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 988) dma_resv_lock(dmabuf->resv, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 989) list_add(&attach->node, &dmabuf->attachments);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 990) dma_resv_unlock(dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 991)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 992) /* When either the importer or the exporter can't handle dynamic
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 993) * mappings we cache the mapping here to avoid issues with the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 994) * reservation object lock.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 995) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 996) if (dma_buf_attachment_is_dynamic(attach) !=
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 997) dma_buf_is_dynamic(dmabuf)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 998) struct sg_table *sgt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 999)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1000) if (dma_buf_is_dynamic(attach->dmabuf)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1001) dma_resv_lock(attach->dmabuf->resv, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1002) ret = dma_buf_pin(attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1003) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1004) goto err_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1005) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1006)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1007) sgt = dmabuf->ops->map_dma_buf(attach, DMA_BIDIRECTIONAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1008) if (!sgt)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1009) sgt = ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1010) if (IS_ERR(sgt)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1011) ret = PTR_ERR(sgt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1012) goto err_unpin;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1013) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1014) if (dma_buf_is_dynamic(attach->dmabuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1015) dma_resv_unlock(attach->dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1016) attach->sgt = sgt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1017) attach->dir = DMA_BIDIRECTIONAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1018) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1019)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1020) return attach;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1021)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1022) err_attach:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1023) kfree(attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1024) return ERR_PTR(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1025)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1026) err_unpin:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1027) if (dma_buf_is_dynamic(attach->dmabuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1028) dma_buf_unpin(attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1029)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1030) err_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1031) if (dma_buf_is_dynamic(attach->dmabuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1032) dma_resv_unlock(attach->dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1033)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1034) dma_buf_detach(dmabuf, attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1035) return ERR_PTR(ret);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1036) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1037) EXPORT_SYMBOL_GPL(dma_buf_dynamic_attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1038)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1039) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1040) * dma_buf_attach - Wrapper for dma_buf_dynamic_attach
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1041) * @dmabuf: [in] buffer to attach device to.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1042) * @dev: [in] device to be attached.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1043) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1044) * Wrapper to call dma_buf_dynamic_attach() for drivers which still use a static
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1045) * mapping.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1046) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1047) struct dma_buf_attachment *dma_buf_attach(struct dma_buf *dmabuf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1048) struct device *dev)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1049) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1050) return dma_buf_dynamic_attach(dmabuf, dev, NULL, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1051) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1052) EXPORT_SYMBOL_GPL(dma_buf_attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1053)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1054) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1055) * dma_buf_detach - Remove the given attachment from dmabuf's attachments list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1056) * optionally calls detach() of dma_buf_ops for device-specific detach
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1057) * @dmabuf: [in] buffer to detach from.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1058) * @attach: [in] attachment to be detached; is free'd after this call.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1059) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1060) * Clean up a device attachment obtained by calling dma_buf_attach().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1061) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1062) void dma_buf_detach(struct dma_buf *dmabuf, struct dma_buf_attachment *attach)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1063) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1064) if (WARN_ON(!dmabuf || !attach))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1065) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1066)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1067) if (attach->sgt) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1068) if (dma_buf_is_dynamic(attach->dmabuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1069) dma_resv_lock(attach->dmabuf->resv, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1070)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1071) dmabuf->ops->unmap_dma_buf(attach, attach->sgt, attach->dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1072)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1073) if (dma_buf_is_dynamic(attach->dmabuf)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1074) dma_buf_unpin(attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1075) dma_resv_unlock(attach->dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1076) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1077) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1078)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1079) dma_resv_lock(dmabuf->resv, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1080) list_del(&attach->node);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1081) dma_resv_unlock(dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1082) if (dmabuf->ops->detach)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1083) dmabuf->ops->detach(dmabuf, attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1084)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1085) kfree(attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1086) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1087) EXPORT_SYMBOL_GPL(dma_buf_detach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1088)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1089) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1090) * dma_buf_pin - Lock down the DMA-buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1091) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1092) * @attach: [in] attachment which should be pinned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1093) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1094) * Returns:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1095) * 0 on success, negative error code on failure.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1096) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1097) int dma_buf_pin(struct dma_buf_attachment *attach)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1098) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1099) struct dma_buf *dmabuf = attach->dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1100) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1101)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1102) dma_resv_assert_held(dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1103)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1104) if (dmabuf->ops->pin)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1105) ret = dmabuf->ops->pin(attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1106)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1107) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1108) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1109) EXPORT_SYMBOL_GPL(dma_buf_pin);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1111) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1112) * dma_buf_unpin - Remove lock from DMA-buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1113) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1114) * @attach: [in] attachment which should be unpinned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1115) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1116) void dma_buf_unpin(struct dma_buf_attachment *attach)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1117) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1118) struct dma_buf *dmabuf = attach->dmabuf;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1119)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1120) dma_resv_assert_held(dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1121)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1122) if (dmabuf->ops->unpin)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1123) dmabuf->ops->unpin(attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1125) EXPORT_SYMBOL_GPL(dma_buf_unpin);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1126)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1127) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1128) * dma_buf_map_attachment - Returns the scatterlist table of the attachment;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1129) * mapped into _device_ address space. Is a wrapper for map_dma_buf() of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1130) * dma_buf_ops.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1131) * @attach: [in] attachment whose scatterlist is to be returned
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1132) * @direction: [in] direction of DMA transfer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1133) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1134) * Returns sg_table containing the scatterlist to be returned; returns ERR_PTR
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1135) * on error. May return -EINTR if it is interrupted by a signal.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1136) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1137) * A mapping must be unmapped by using dma_buf_unmap_attachment(). Note that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1138) * the underlying backing storage is pinned for as long as a mapping exists,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1139) * therefore users/importers should not hold onto a mapping for undue amounts of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1140) * time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1141) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1142) struct sg_table *dma_buf_map_attachment(struct dma_buf_attachment *attach,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1143) enum dma_data_direction direction)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1144) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1145) struct sg_table *sg_table;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1146) int r;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1147)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1148) might_sleep();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1150) if (WARN_ON(!attach || !attach->dmabuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1151) return ERR_PTR(-EINVAL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1152)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1153) if (dma_buf_attachment_is_dynamic(attach))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1154) dma_resv_assert_held(attach->dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1156) if (attach->sgt) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1157) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1158) * Two mappings with different directions for the same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1159) * attachment are not allowed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1160) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1161) if (attach->dir != direction &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1162) attach->dir != DMA_BIDIRECTIONAL)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1163) return ERR_PTR(-EBUSY);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1165) return attach->sgt;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1166) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1167)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1168) if (dma_buf_is_dynamic(attach->dmabuf)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1169) dma_resv_assert_held(attach->dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1170) if (!IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1171) r = dma_buf_pin(attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1172) if (r)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1173) return ERR_PTR(r);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1174) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1175) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1176)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1177) sg_table = attach->dmabuf->ops->map_dma_buf(attach, direction);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1178) if (!sg_table)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1179) sg_table = ERR_PTR(-ENOMEM);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1180)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1181) if (IS_ERR(sg_table) && dma_buf_is_dynamic(attach->dmabuf) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1182) !IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1183) dma_buf_unpin(attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1184)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1185) if (!IS_ERR(sg_table) && attach->dmabuf->ops->cache_sgt_mapping) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1186) attach->sgt = sg_table;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1187) attach->dir = direction;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1188) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1189)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1190) return sg_table;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1191) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1192) EXPORT_SYMBOL_GPL(dma_buf_map_attachment);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1193)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1194) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1195) * dma_buf_unmap_attachment - unmaps and decreases usecount of the buffer;might
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1196) * deallocate the scatterlist associated. Is a wrapper for unmap_dma_buf() of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1197) * dma_buf_ops.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1198) * @attach: [in] attachment to unmap buffer from
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1199) * @sg_table: [in] scatterlist info of the buffer to unmap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1200) * @direction: [in] direction of DMA transfer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1201) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1202) * This unmaps a DMA mapping for @attached obtained by dma_buf_map_attachment().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1203) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1204) void dma_buf_unmap_attachment(struct dma_buf_attachment *attach,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1205) struct sg_table *sg_table,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1206) enum dma_data_direction direction)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1207) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1208) might_sleep();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1209)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1210) if (WARN_ON(!attach || !attach->dmabuf || !sg_table))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1211) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1212)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1213) if (dma_buf_attachment_is_dynamic(attach))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1214) dma_resv_assert_held(attach->dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1215)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1216) if (attach->sgt == sg_table)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1217) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1218)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1219) if (dma_buf_is_dynamic(attach->dmabuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1220) dma_resv_assert_held(attach->dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1221)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1222) attach->dmabuf->ops->unmap_dma_buf(attach, sg_table, direction);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1223)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1224) if (dma_buf_is_dynamic(attach->dmabuf) &&
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1225) !IS_ENABLED(CONFIG_DMABUF_MOVE_NOTIFY))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1226) dma_buf_unpin(attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1227) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1228) EXPORT_SYMBOL_GPL(dma_buf_unmap_attachment);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1229)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1230) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1231) * dma_buf_move_notify - notify attachments that DMA-buf is moving
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1232) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1233) * @dmabuf: [in] buffer which is moving
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1234) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1235) * Informs all attachmenst that they need to destroy and recreated all their
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1236) * mappings.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1237) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1238) void dma_buf_move_notify(struct dma_buf *dmabuf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1239) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1240) struct dma_buf_attachment *attach;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1241)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1242) dma_resv_assert_held(dmabuf->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1243)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1244) list_for_each_entry(attach, &dmabuf->attachments, node)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1245) if (attach->importer_ops)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1246) attach->importer_ops->move_notify(attach);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1247) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1248) EXPORT_SYMBOL_GPL(dma_buf_move_notify);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1249)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1250) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1251) * DOC: cpu access
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1252) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1253) * There are mutliple reasons for supporting CPU access to a dma buffer object:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1254) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1255) * - Fallback operations in the kernel, for example when a device is connected
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1256) * over USB and the kernel needs to shuffle the data around first before
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1257) * sending it away. Cache coherency is handled by braketing any transactions
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1258) * with calls to dma_buf_begin_cpu_access() and dma_buf_end_cpu_access()
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1259) * access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1260) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1261) * Since for most kernel internal dma-buf accesses need the entire buffer, a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1262) * vmap interface is introduced. Note that on very old 32-bit architectures
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1263) * vmalloc space might be limited and result in vmap calls failing.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1264) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1265) * Interfaces::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1266) * void \*dma_buf_vmap(struct dma_buf \*dmabuf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1267) * void dma_buf_vunmap(struct dma_buf \*dmabuf, void \*vaddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1268) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1269) * The vmap call can fail if there is no vmap support in the exporter, or if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1270) * it runs out of vmalloc space. Fallback to kmap should be implemented. Note
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1271) * that the dma-buf layer keeps a reference count for all vmap access and
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1272) * calls down into the exporter's vmap function only when no vmapping exists,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1273) * and only unmaps it once. Protection against concurrent vmap/vunmap calls is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1274) * provided by taking the dma_buf->lock mutex.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1275) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1276) * - For full compatibility on the importer side with existing userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1277) * interfaces, which might already support mmap'ing buffers. This is needed in
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1278) * many processing pipelines (e.g. feeding a software rendered image into a
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1279) * hardware pipeline, thumbnail creation, snapshots, ...). Also, Android's ION
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1280) * framework already supported this and for DMA buffer file descriptors to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1281) * replace ION buffers mmap support was needed.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1282) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1283) * There is no special interfaces, userspace simply calls mmap on the dma-buf
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1284) * fd. But like for CPU access there's a need to braket the actual access,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1285) * which is handled by the ioctl (DMA_BUF_IOCTL_SYNC). Note that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1286) * DMA_BUF_IOCTL_SYNC can fail with -EAGAIN or -EINTR, in which case it must
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1287) * be restarted.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1288) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1289) * Some systems might need some sort of cache coherency management e.g. when
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1290) * CPU and GPU domains are being accessed through dma-buf at the same time.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1291) * To circumvent this problem there are begin/end coherency markers, that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1292) * forward directly to existing dma-buf device drivers vfunc hooks. Userspace
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1293) * can make use of those markers through the DMA_BUF_IOCTL_SYNC ioctl. The
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1294) * sequence would be used like following:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1295) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1296) * - mmap dma-buf fd
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1297) * - for each drawing/upload cycle in CPU 1. SYNC_START ioctl, 2. read/write
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1298) * to mmap area 3. SYNC_END ioctl. This can be repeated as often as you
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1299) * want (with the new data being consumed by say the GPU or the scanout
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1300) * device)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1301) * - munmap once you don't need the buffer any more
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1302) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1303) * For correctness and optimal performance, it is always required to use
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1304) * SYNC_START and SYNC_END before and after, respectively, when accessing the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1305) * mapped address. Userspace cannot rely on coherent access, even when there
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1306) * are systems where it just works without calling these ioctls.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1307) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1308) * - And as a CPU fallback in userspace processing pipelines.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1309) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1310) * Similar to the motivation for kernel cpu access it is again important that
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1311) * the userspace code of a given importing subsystem can use the same
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1312) * interfaces with a imported dma-buf buffer object as with a native buffer
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1313) * object. This is especially important for drm where the userspace part of
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1314) * contemporary OpenGL, X, and other drivers is huge, and reworking them to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1315) * use a different way to mmap a buffer rather invasive.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1316) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1317) * The assumption in the current dma-buf interfaces is that redirecting the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1318) * initial mmap is all that's needed. A survey of some of the existing
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1319) * subsystems shows that no driver seems to do any nefarious thing like
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1320) * syncing up with outstanding asynchronous processing on the device or
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1321) * allocating special resources at fault time. So hopefully this is good
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1322) * enough, since adding interfaces to intercept pagefaults and allow pte
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1323) * shootdowns would increase the complexity quite a bit.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1324) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1325) * Interface::
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1326) * int dma_buf_mmap(struct dma_buf \*, struct vm_area_struct \*,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1327) * unsigned long);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1328) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1329) * If the importing subsystem simply provides a special-purpose mmap call to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1330) * set up a mapping in userspace, calling do_mmap with dma_buf->file will
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1331) * equally achieve that for a dma-buf object.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1332) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1333)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1334) static int __dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1335) enum dma_data_direction direction)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1336) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1337) bool write = (direction == DMA_BIDIRECTIONAL ||
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1338) direction == DMA_TO_DEVICE);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1339) struct dma_resv *resv = dmabuf->resv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1340) long ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1341)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1342) /* Wait on any implicit rendering fences */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1343) ret = dma_resv_wait_timeout_rcu(resv, write, true,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1344) MAX_SCHEDULE_TIMEOUT);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1345) if (ret < 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1346) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1347)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1348) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1349) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1350)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1351) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1352) * dma_buf_begin_cpu_access - Must be called before accessing a dma_buf from the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1353) * cpu in the kernel context. Calls begin_cpu_access to allow exporter-specific
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1354) * preparations. Coherency is only guaranteed in the specified range for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1355) * specified access direction.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1356) * @dmabuf: [in] buffer to prepare cpu access for.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1357) * @direction: [in] length of range for cpu access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1358) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1359) * After the cpu access is complete the caller should call
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1360) * dma_buf_end_cpu_access(). Only when cpu access is braketed by both calls is
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1361) * it guaranteed to be coherent with other DMA access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1362) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1363) * Can return negative error values, returns 0 on success.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1364) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1365) int dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1366) enum dma_data_direction direction)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1367) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1368) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1369)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1370) if (WARN_ON(!dmabuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1371) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1372)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1373) if (dmabuf->ops->begin_cpu_access)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1374) ret = dmabuf->ops->begin_cpu_access(dmabuf, direction);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1375)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1376) /* Ensure that all fences are waited upon - but we first allow
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1377) * the native handler the chance to do so more efficiently if it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1378) * chooses. A double invocation here will be reasonably cheap no-op.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1379) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1380) if (ret == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1381) ret = __dma_buf_begin_cpu_access(dmabuf, direction);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1382)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1383) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1384) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1385) EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1386)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1387) int dma_buf_begin_cpu_access_partial(struct dma_buf *dmabuf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1388) enum dma_data_direction direction,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1389) unsigned int offset, unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1390) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1391) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1392)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1393) if (WARN_ON(!dmabuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1394) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1395)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1396) if (dmabuf->ops->begin_cpu_access_partial)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1397) ret = dmabuf->ops->begin_cpu_access_partial(dmabuf, direction,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1398) offset, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1399)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1400) /* Ensure that all fences are waited upon - but we first allow
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1401) * the native handler the chance to do so more efficiently if it
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1402) * chooses. A double invocation here will be reasonably cheap no-op.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1403) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1404) if (ret == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1405) ret = __dma_buf_begin_cpu_access(dmabuf, direction);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1406)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1407) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1408) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1409) EXPORT_SYMBOL_GPL(dma_buf_begin_cpu_access_partial);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1410)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1411) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1412) * dma_buf_end_cpu_access - Must be called after accessing a dma_buf from the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1413) * cpu in the kernel context. Calls end_cpu_access to allow exporter-specific
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1414) * actions. Coherency is only guaranteed in the specified range for the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1415) * specified access direction.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1416) * @dmabuf: [in] buffer to complete cpu access for.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1417) * @direction: [in] length of range for cpu access.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1418) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1419) * This terminates CPU access started with dma_buf_begin_cpu_access().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1420) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1421) * Can return negative error values, returns 0 on success.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1422) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1423) int dma_buf_end_cpu_access(struct dma_buf *dmabuf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1424) enum dma_data_direction direction)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1425) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1426) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1427)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1428) WARN_ON(!dmabuf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1429)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1430) if (dmabuf->ops->end_cpu_access)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1431) ret = dmabuf->ops->end_cpu_access(dmabuf, direction);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1432)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1433) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1434) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1435) EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1436)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1437) int dma_buf_end_cpu_access_partial(struct dma_buf *dmabuf,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1438) enum dma_data_direction direction,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1439) unsigned int offset, unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1440) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1441) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1442)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1443) WARN_ON(!dmabuf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1444)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1445) if (dmabuf->ops->end_cpu_access_partial)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1446) ret = dmabuf->ops->end_cpu_access_partial(dmabuf, direction,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1447) offset, len);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1448)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1449) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1450) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1451) EXPORT_SYMBOL_GPL(dma_buf_end_cpu_access_partial);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1452)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1453) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1454) * dma_buf_mmap - Setup up a userspace mmap with the given vma
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1455) * @dmabuf: [in] buffer that should back the vma
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1456) * @vma: [in] vma for the mmap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1457) * @pgoff: [in] offset in pages where this mmap should start within the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1458) * dma-buf buffer.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1459) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1460) * This function adjusts the passed in vma so that it points at the file of the
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1461) * dma_buf operation. It also adjusts the starting pgoff and does bounds
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1462) * checking on the size of the vma. Then it calls the exporters mmap function to
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1463) * set up the mapping.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1464) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1465) * Can return negative error values, returns 0 on success.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1466) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1467) int dma_buf_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1468) unsigned long pgoff)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1469) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1470) struct file *oldfile;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1471) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1472)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1473) if (WARN_ON(!dmabuf || !vma))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1474) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1475)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1476) /* check if buffer supports mmap */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1477) if (!dmabuf->ops->mmap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1478) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1479)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1480) /* check for offset overflow */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1481) if (pgoff + vma_pages(vma) < pgoff)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1482) return -EOVERFLOW;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1483)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1484) /* check for overflowing the buffer's size */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1485) if (pgoff + vma_pages(vma) >
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1486) dmabuf->size >> PAGE_SHIFT)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1487) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1488)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1489) /* readjust the vma */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1490) get_file(dmabuf->file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1491) oldfile = vma->vm_file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1492) vma->vm_file = dmabuf->file;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1493) vma->vm_pgoff = pgoff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1494)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1495) ret = dmabuf->ops->mmap(dmabuf, vma);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1496) if (ret) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1497) /* restore old parameters on failure */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1498) vma->vm_file = oldfile;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1499) fput(dmabuf->file);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1500) } else {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1501) if (oldfile)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1502) fput(oldfile);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1503) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1504) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1505)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1506) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1507) EXPORT_SYMBOL_GPL(dma_buf_mmap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1508)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1509) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1510) * dma_buf_vmap - Create virtual mapping for the buffer object into kernel
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1511) * address space. Same restrictions as for vmap and friends apply.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1512) * @dmabuf: [in] buffer to vmap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1513) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1514) * This call may fail due to lack of virtual mapping address space.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1515) * These calls are optional in drivers. The intended use for them
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1516) * is for mapping objects linear in kernel space for high use objects.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1517) * Please attempt to use kmap/kunmap before thinking about these interfaces.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1518) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1519) * Returns NULL on error.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1520) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1521) void *dma_buf_vmap(struct dma_buf *dmabuf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1522) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1523) void *ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1524)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1525) if (WARN_ON(!dmabuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1526) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1527)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1528) if (!dmabuf->ops->vmap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1529) return NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1530)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1531) mutex_lock(&dmabuf->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1532) if (dmabuf->vmapping_counter) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1533) dmabuf->vmapping_counter++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1534) BUG_ON(!dmabuf->vmap_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1535) ptr = dmabuf->vmap_ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1536) goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1537) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1538)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1539) BUG_ON(dmabuf->vmap_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1540)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1541) ptr = dmabuf->ops->vmap(dmabuf);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1542) if (WARN_ON_ONCE(IS_ERR(ptr)))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1543) ptr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1544) if (!ptr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1545) goto out_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1546)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1547) dmabuf->vmap_ptr = ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1548) dmabuf->vmapping_counter = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1549)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1550) out_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1551) mutex_unlock(&dmabuf->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1552) return ptr;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1553) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1554) EXPORT_SYMBOL_GPL(dma_buf_vmap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1555)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1556) /**
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1557) * dma_buf_vunmap - Unmap a vmap obtained by dma_buf_vmap.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1558) * @dmabuf: [in] buffer to vunmap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1559) * @vaddr: [in] vmap to vunmap
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1560) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1561) void dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1562) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1563) if (WARN_ON(!dmabuf))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1564) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1565)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1566) BUG_ON(!dmabuf->vmap_ptr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1567) BUG_ON(dmabuf->vmapping_counter == 0);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1568) BUG_ON(dmabuf->vmap_ptr != vaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1569)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1570) mutex_lock(&dmabuf->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1571) if (--dmabuf->vmapping_counter == 0) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1572) if (dmabuf->ops->vunmap)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1573) dmabuf->ops->vunmap(dmabuf, vaddr);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1574) dmabuf->vmap_ptr = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1575) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1576) mutex_unlock(&dmabuf->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1577) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1578) EXPORT_SYMBOL_GPL(dma_buf_vunmap);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1579)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1580) int dma_buf_get_flags(struct dma_buf *dmabuf, unsigned long *flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1581) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1582) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1583)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1584) if (WARN_ON(!dmabuf) || !flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1585) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1586)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1587) if (dmabuf->ops->get_flags)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1588) ret = dmabuf->ops->get_flags(dmabuf, flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1589)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1590) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1591) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1592) EXPORT_SYMBOL_GPL(dma_buf_get_flags);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1593)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1594) int dma_buf_get_uuid(struct dma_buf *dmabuf, uuid_t *uuid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1595) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1596) if (WARN_ON(!dmabuf) || !uuid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1597) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1598)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1599) if (!dmabuf->ops->get_uuid)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1600) return -ENODEV;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1601)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1602) return dmabuf->ops->get_uuid(dmabuf, uuid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1603) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1604) EXPORT_SYMBOL_GPL(dma_buf_get_uuid);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1605)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1606) #ifdef CONFIG_DEBUG_FS
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1607) static int dma_buf_debug_show(struct seq_file *s, void *unused)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1608) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1609) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1610) struct dma_buf *buf_obj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1611) struct dma_buf_attachment *attach_obj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1612) struct dma_resv *robj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1613) struct dma_resv_list *fobj;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1614) struct dma_fence *fence;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1615) unsigned seq;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1616) int count = 0, attach_count, shared_count, i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1617) size_t size = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1618)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1619) ret = mutex_lock_interruptible(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1620)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1621) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1622) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1623)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1624) seq_puts(s, "\nDma-buf Objects:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1625) seq_printf(s, "%-8s\t%-8s\t%-8s\t%-8s\texp_name\t%-8s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1626) "size", "flags", "mode", "count", "ino");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1627)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1628) list_for_each_entry(buf_obj, &db_list.head, list_node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1629)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1630) ret = dma_resv_lock_interruptible(buf_obj->resv, NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1631) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1632) goto error_unlock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1633)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1634) spin_lock(&buf_obj->name_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1635) seq_printf(s, "%08zu\t%08x\t%08x\t%08ld\t%s\t%08lu\t%s\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1636) buf_obj->size,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1637) buf_obj->file->f_flags, buf_obj->file->f_mode,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1638) file_count(buf_obj->file),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1639) buf_obj->exp_name,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1640) file_inode(buf_obj->file)->i_ino,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1641) buf_obj->name ?: "");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1642) spin_unlock(&buf_obj->name_lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1643)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1644) robj = buf_obj->resv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1645) while (true) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1646) seq = read_seqcount_begin(&robj->seq);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1647) rcu_read_lock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1648) fobj = rcu_dereference(robj->fence);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1649) shared_count = fobj ? fobj->shared_count : 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1650) fence = rcu_dereference(robj->fence_excl);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1651) if (!read_seqcount_retry(&robj->seq, seq))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1652) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1653) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1654) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1655)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1656) if (fence)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1657) seq_printf(s, "\tExclusive fence: %s %s %ssignalled\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1658) fence->ops->get_driver_name(fence),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1659) fence->ops->get_timeline_name(fence),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1660) dma_fence_is_signaled(fence) ? "" : "un");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1661) for (i = 0; i < shared_count; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1662) fence = rcu_dereference(fobj->shared[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1663) if (!dma_fence_get_rcu(fence))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1664) continue;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1665) seq_printf(s, "\tShared fence: %s %s %ssignalled\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1666) fence->ops->get_driver_name(fence),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1667) fence->ops->get_timeline_name(fence),
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1668) dma_fence_is_signaled(fence) ? "" : "un");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1669) dma_fence_put(fence);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1670) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1671) rcu_read_unlock();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1672)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1673) seq_puts(s, "\tAttached Devices:\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1674) attach_count = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1675)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1676) list_for_each_entry(attach_obj, &buf_obj->attachments, node) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1677) seq_printf(s, "\t%s\n", dev_name(attach_obj->dev));
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1678) attach_count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1679) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1680) dma_resv_unlock(buf_obj->resv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1681)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1682) seq_printf(s, "Total %d devices attached\n\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1683) attach_count);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1684)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1685) count++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1686) size += buf_obj->size;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1687) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1688)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1689) seq_printf(s, "\nTotal %d objects, %zu bytes\n", count, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1690)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1691) mutex_unlock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1692) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1693)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1694) error_unlock:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1695) mutex_unlock(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1696) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1697) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1698)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1699) DEFINE_SHOW_ATTRIBUTE(dma_buf_debug);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1700)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1701) static struct dentry *dma_buf_debugfs_dir;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1702)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1703) static int dma_buf_init_debugfs(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1704) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1705) struct dentry *d;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1706) int err = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1707)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1708) d = debugfs_create_dir("dma_buf", NULL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1709) if (IS_ERR(d))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1710) return PTR_ERR(d);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1711)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1712) dma_buf_debugfs_dir = d;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1713)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1714) d = debugfs_create_file("bufinfo", S_IRUGO, dma_buf_debugfs_dir,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1715) NULL, &dma_buf_debug_fops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1716) if (IS_ERR(d)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1717) pr_debug("dma_buf: debugfs: failed to create node bufinfo\n");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1718) debugfs_remove_recursive(dma_buf_debugfs_dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1719) dma_buf_debugfs_dir = NULL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1720) err = PTR_ERR(d);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1721) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1722)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1723) return err;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1724) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1725)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1726) static void dma_buf_uninit_debugfs(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1727) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1728) debugfs_remove_recursive(dma_buf_debugfs_dir);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1729) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1730) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1731) static inline int dma_buf_init_debugfs(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1732) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1733) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1734) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1735) static inline void dma_buf_uninit_debugfs(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1736) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1737) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1738) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1739)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1740) static int __init dma_buf_init(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1741) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1742) int ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1743)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1744) ret = dma_buf_init_sysfs_statistics();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1745) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1746) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1747)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1748) dma_buf_mnt = kern_mount(&dma_buf_fs_type);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1749) if (IS_ERR(dma_buf_mnt))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1750) return PTR_ERR(dma_buf_mnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1751)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1752) mutex_init(&db_list.lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1753) INIT_LIST_HEAD(&db_list.head);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1754) dma_buf_init_debugfs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1755) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1756) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1757) subsys_initcall(dma_buf_init);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1758)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1759) static void __exit dma_buf_deinit(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1760) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1761) dma_buf_uninit_debugfs();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1762) kern_unmount(dma_buf_mnt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1763) dma_buf_uninit_sysfs_statistics();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1764) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1765) __exitcall(dma_buf_deinit);
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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