Orange Pi5 kernel

/*
 * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
 *
 * This file is released under the GPL.
 */
 
#include "dm.h"
#include <linux/module.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/dax.h>
#include <linux/slab.h>
#include <linux/device-mapper.h>
 
#define DM_MSG_PREFIX "linear"
 
/*
 * Linear: maps a linear range of a device.
 */
struct linear_c {
<------>struct dm_dev *dev;
<------>sector_t start;
};
 
/*
 * Construct a linear mapping: <dev_path> <offset>
 */
static int linear_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{
<------>struct linear_c *lc;
<------>unsigned long long tmp;
<------>char dummy;
<------>int ret;
 
<------>if (argc != 2) {
<------><------>ti->error = "Invalid argument count";
<------><------>return -EINVAL;
<------>}
 
<------>lc = kmalloc(sizeof(*lc), GFP_KERNEL);
<------>if (lc == NULL) {
<------><------>ti->error = "Cannot allocate linear context";
<------><------>return -ENOMEM;
<------>}
 
<------>ret = -EINVAL;
<------>if (sscanf(argv[1], "%llu%c", &tmp, &dummy) != 1 || tmp != (sector_t)tmp) {
<------><------>ti->error = "Invalid device sector";
<------><------>goto bad;
<------>}
<------>lc->start = tmp;
 
<------>ret = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &lc->dev);
<------>if (ret) {
<------><------>ti->error = "Device lookup failed";
<------><------>goto bad;
<------>}
 
<------>ti->num_flush_bios = 1;
<------>ti->num_discard_bios = 1;
<------>ti->num_secure_erase_bios = 1;
<------>ti->num_write_same_bios = 1;
<------>ti->num_write_zeroes_bios = 1;
<------>ti->private = lc;
<------>return 0;
 
      bad:
<------>kfree(lc);
<------>return ret;
}
 
static void linear_dtr(struct dm_target *ti)
{
<------>struct linear_c *lc = (struct linear_c *) ti->private;
 
<------>dm_put_device(ti, lc->dev);
<------>kfree(lc);
}
 
static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector)
{
<------>struct linear_c *lc = ti->private;
 
<------>return lc->start + dm_target_offset(ti, bi_sector);
}
 
static void linear_map_bio(struct dm_target *ti, struct bio *bio)
{
<------>struct linear_c *lc = ti->private;
 
<------>bio_set_dev(bio, lc->dev->bdev);
<------>if (bio_sectors(bio) || op_is_zone_mgmt(bio_op(bio)))
<------><------>bio->bi_iter.bi_sector =
<------><------><------>linear_map_sector(ti, bio->bi_iter.bi_sector);
}
 
static int linear_map(struct dm_target *ti, struct bio *bio)
{
<------>linear_map_bio(ti, bio);
 
<------>return DM_MAPIO_REMAPPED;
}
 
static void linear_status(struct dm_target *ti, status_type_t type,
<------><------><------>  unsigned status_flags, char *result, unsigned maxlen)
{
<------>struct linear_c *lc = (struct linear_c *) ti->private;
 
<------>switch (type) {
<------>case STATUSTYPE_INFO:
<------><------>result[0] = '\0';
<------><------>break;
 
<------>case STATUSTYPE_TABLE:
<------><------>snprintf(result, maxlen, "%s %llu", lc->dev->name,
<------><------><------><------>(unsigned long long)lc->start);
<------><------>break;
<------>}
}
 
static int linear_prepare_ioctl(struct dm_target *ti, struct block_device **bdev)
{
<------>struct linear_c *lc = (struct linear_c *) ti->private;
<------>struct dm_dev *dev = lc->dev;
 
<------>*bdev = dev->bdev;
 
<------>/*
<------> * Only pass ioctls through if the device sizes match exactly.
<------> */
<------>if (lc->start ||
<------>    ti->len != i_size_read(dev->bdev->bd_inode) >> SECTOR_SHIFT)
<------><------>return 1;
<------>return 0;
}
 
#ifdef CONFIG_BLK_DEV_ZONED
static int linear_report_zones(struct dm_target *ti,
<------><------>struct dm_report_zones_args *args, unsigned int nr_zones)
{
<------>struct linear_c *lc = ti->private;
<------>sector_t sector = linear_map_sector(ti, args->next_sector);
 
<------>args->start = lc->start;
<------>return blkdev_report_zones(lc->dev->bdev, sector, nr_zones,
<------><------><------><------>   dm_report_zones_cb, args);
}
#endif
 
static int linear_iterate_devices(struct dm_target *ti,
<------><------><------><------>  iterate_devices_callout_fn fn, void *data)
{
<------>struct linear_c *lc = ti->private;
 
<------>return fn(ti, lc->dev, lc->start, ti->len, data);
}
 
#if IS_ENABLED(CONFIG_DAX_DRIVER)
static long linear_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
<------><------>long nr_pages, void **kaddr, pfn_t *pfn)
{
<------>long ret;
<------>struct linear_c *lc = ti->private;
<------>struct block_device *bdev = lc->dev->bdev;
<------>struct dax_device *dax_dev = lc->dev->dax_dev;
<------>sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
 
<------>dev_sector = linear_map_sector(ti, sector);
<------>ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages * PAGE_SIZE, &pgoff);
<------>if (ret)
<------><------>return ret;
<------>return dax_direct_access(dax_dev, pgoff, nr_pages, kaddr, pfn);
}
 
static size_t linear_dax_copy_from_iter(struct dm_target *ti, pgoff_t pgoff,
<------><------>void *addr, size_t bytes, struct iov_iter *i)
{
<------>struct linear_c *lc = ti->private;
<------>struct block_device *bdev = lc->dev->bdev;
<------>struct dax_device *dax_dev = lc->dev->dax_dev;
<------>sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
 
<------>dev_sector = linear_map_sector(ti, sector);
<------>if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
<------><------>return 0;
<------>return dax_copy_from_iter(dax_dev, pgoff, addr, bytes, i);
}
 
static size_t linear_dax_copy_to_iter(struct dm_target *ti, pgoff_t pgoff,
<------><------>void *addr, size_t bytes, struct iov_iter *i)
{
<------>struct linear_c *lc = ti->private;
<------>struct block_device *bdev = lc->dev->bdev;
<------>struct dax_device *dax_dev = lc->dev->dax_dev;
<------>sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
 
<------>dev_sector = linear_map_sector(ti, sector);
<------>if (bdev_dax_pgoff(bdev, dev_sector, ALIGN(bytes, PAGE_SIZE), &pgoff))
<------><------>return 0;
<------>return dax_copy_to_iter(dax_dev, pgoff, addr, bytes, i);
}
 
static int linear_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
<------><------><------><------>      size_t nr_pages)
{
<------>int ret;
<------>struct linear_c *lc = ti->private;
<------>struct block_device *bdev = lc->dev->bdev;
<------>struct dax_device *dax_dev = lc->dev->dax_dev;
<------>sector_t dev_sector, sector = pgoff * PAGE_SECTORS;
 
<------>dev_sector = linear_map_sector(ti, sector);
<------>ret = bdev_dax_pgoff(bdev, dev_sector, nr_pages << PAGE_SHIFT, &pgoff);
<------>if (ret)
<------><------>return ret;
<------>return dax_zero_page_range(dax_dev, pgoff, nr_pages);
}
 
#else
#define linear_dax_direct_access NULL
#define linear_dax_copy_from_iter NULL
#define linear_dax_copy_to_iter NULL
#define linear_dax_zero_page_range NULL
#endif
 
static struct target_type linear_target = {
<------>.name   = "linear",
<------>.version = {1, 4, 0},
#ifdef CONFIG_BLK_DEV_ZONED
<------>.features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT |
<------><------>    DM_TARGET_ZONED_HM | DM_TARGET_PASSES_CRYPTO,
<------>.report_zones = linear_report_zones,
#else
<------>.features = DM_TARGET_PASSES_INTEGRITY | DM_TARGET_NOWAIT |
<------><------>    DM_TARGET_PASSES_CRYPTO,
#endif
<------>.module = THIS_MODULE,
<------>.ctr    = linear_ctr,
<------>.dtr    = linear_dtr,
<------>.map    = linear_map,
<------>.status = linear_status,
<------>.prepare_ioctl = linear_prepare_ioctl,
<------>.iterate_devices = linear_iterate_devices,
<------>.direct_access = linear_dax_direct_access,
<------>.dax_copy_from_iter = linear_dax_copy_from_iter,
<------>.dax_copy_to_iter = linear_dax_copy_to_iter,
<------>.dax_zero_page_range = linear_dax_zero_page_range,
};
 
int __init dm_linear_init(void)
{
<------>int r = dm_register_target(&linear_target);
 
<------>if (r < 0)
<------><------>DMERR("register failed %d", r);
 
<------>return r;
}
 
void dm_linear_exit(void)
{
<------>dm_unregister_target(&linear_target);
}