Orange Pi5 kernel

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020 Intel
 *
 * Based on drivers/base/devres.c
 */
 
#include <drm/drm_managed.h>
 
#include <linux/list.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
 
#include <drm/drm_device.h>
#include <drm/drm_print.h>
 
#include "drm_internal.h"
 
/**
 * DOC: managed resources
 *
 * Inspired by struct &device managed resources, but tied to the lifetime of
 * struct &drm_device, which can outlive the underlying physical device, usually
 * when userspace has some open files and other handles to resources still open.
 *
 * Release actions can be added with drmm_add_action(), memory allocations can
 * be done directly with drmm_kmalloc() and the related functions. Everything
 * will be released on the final drm_dev_put() in reverse order of how the
 * release actions have been added and memory has been allocated since driver
 * loading started with devm_drm_dev_alloc().
 *
 * Note that release actions and managed memory can also be added and removed
 * during the lifetime of the driver, all the functions are fully concurrent
 * safe. But it is recommended to use managed resources only for resources that
 * change rarely, if ever, during the lifetime of the &drm_device instance.
 */
 
struct drmres_node {
<------>struct list_head	entry;
<------>drmres_release_t	release;
<------>const char		*name;
<------>size_t			size;
};
 
struct drmres {
<------>struct drmres_node		node;
<------>/*
<------> * Some archs want to perform DMA into kmalloc caches
<------> * and need a guaranteed alignment larger than
<------> * the alignment of a 64-bit integer.
<------> * Thus we use ARCH_KMALLOC_MINALIGN here and get exactly the same
<------> * buffer alignment as if it was allocated by plain kmalloc().
<------> */
<------>u8 __aligned(ARCH_KMALLOC_MINALIGN) data[];
};
 
static void free_dr(struct drmres *dr)
{
<------>kfree_const(dr->node.name);
<------>kfree(dr);
}
 
void drm_managed_release(struct drm_device *dev)
{
<------>struct drmres *dr, *tmp;
 
<------>drm_dbg_drmres(dev, "drmres release begin\n");
<------>list_for_each_entry_safe(dr, tmp, &dev->managed.resources, node.entry) {
<------><------>drm_dbg_drmres(dev, "REL %p %s (%zu bytes)\n",
<------><------><------>       dr, dr->node.name, dr->node.size);
 
<------><------>if (dr->node.release)
<------><------><------>dr->node.release(dev, dr->node.size ? *(void **)&dr->data : NULL);
 
<------><------>list_del(&dr->node.entry);
<------><------>free_dr(dr);
<------>}
<------>drm_dbg_drmres(dev, "drmres release end\n");
}
 
/*
 * Always inline so that kmalloc_track_caller tracks the actual interesting
 * caller outside of drm_managed.c.
 */
static __always_inline struct drmres * alloc_dr(drmres_release_t release,
<------><------><------><------><------><------>size_t size, gfp_t gfp, int nid)
{
<------>size_t tot_size;
<------>struct drmres *dr;
 
<------>/* We must catch any near-SIZE_MAX cases that could overflow. */
<------>if (unlikely(check_add_overflow(sizeof(*dr), size, &tot_size)))
<------><------>return NULL;
 
<------>dr = kmalloc_node_track_caller(tot_size, gfp, nid);
<------>if (unlikely(!dr))
<------><------>return NULL;
 
<------>memset(dr, 0, offsetof(struct drmres, data));
 
<------>INIT_LIST_HEAD(&dr->node.entry);
<------>dr->node.release = release;
<------>dr->node.size = size;
 
<------>return dr;
}
 
static void del_dr(struct drm_device *dev, struct drmres *dr)
{
<------>list_del_init(&dr->node.entry);
 
<------>drm_dbg_drmres(dev, "DEL %p %s (%lu bytes)\n",
<------><------>       dr, dr->node.name, (unsigned long) dr->node.size);
}
 
static void add_dr(struct drm_device *dev, struct drmres *dr)
{
<------>unsigned long flags;
 
<------>spin_lock_irqsave(&dev->managed.lock, flags);
<------>list_add(&dr->node.entry, &dev->managed.resources);
<------>spin_unlock_irqrestore(&dev->managed.lock, flags);
 
<------>drm_dbg_drmres(dev, "ADD %p %s (%lu bytes)\n",
<------><------>       dr, dr->node.name, (unsigned long) dr->node.size);
}
 
void drmm_add_final_kfree(struct drm_device *dev, void *container)
{
<------>WARN_ON(dev->managed.final_kfree);
<------>WARN_ON(dev < (struct drm_device *) container);
<------>WARN_ON(dev + 1 > (struct drm_device *) (container + ksize(container)));
<------>dev->managed.final_kfree = container;
}
 
int __drmm_add_action(struct drm_device *dev,
<------><------>      drmres_release_t action,
<------><------>      void *data, const char *name)
{
<------>struct drmres *dr;
<------>void **void_ptr;
 
<------>dr = alloc_dr(action, data ? sizeof(void*) : 0,
<------><------>      GFP_KERNEL | __GFP_ZERO,
<------><------>      dev_to_node(dev->dev));
<------>if (!dr) {
<------><------>drm_dbg_drmres(dev, "failed to add action %s for %p\n",
<------><------><------>       name, data);
<------><------>return -ENOMEM;
<------>}
 
<------>dr->node.name = kstrdup_const(name, GFP_KERNEL);
<------>if (data) {
<------><------>void_ptr = (void **)&dr->data;
<------><------>*void_ptr = data;
<------>}
 
<------>add_dr(dev, dr);
 
<------>return 0;
}
EXPORT_SYMBOL(__drmm_add_action);
 
int __drmm_add_action_or_reset(struct drm_device *dev,
<------><------><------>       drmres_release_t action,
<------><------><------>       void *data, const char *name)
{
<------>int ret;
 
<------>ret = __drmm_add_action(dev, action, data, name);
<------>if (ret)
<------><------>action(dev, data);
 
<------>return ret;
}
EXPORT_SYMBOL(__drmm_add_action_or_reset);
 
/**
 * drmm_kmalloc - &drm_device managed kmalloc()
 * @dev: DRM device
 * @size: size of the memory allocation
 * @gfp: GFP allocation flags
 *
 * This is a &drm_device managed version of kmalloc(). The allocated memory is
 * automatically freed on the final drm_dev_put(). Memory can also be freed
 * before the final drm_dev_put() by calling drmm_kfree().
 */
void *drmm_kmalloc(struct drm_device *dev, size_t size, gfp_t gfp)
{
<------>struct drmres *dr;
 
<------>dr = alloc_dr(NULL, size, gfp, dev_to_node(dev->dev));
<------>if (!dr) {
<------><------>drm_dbg_drmres(dev, "failed to allocate %zu bytes, %u flags\n",
<------><------><------>       size, gfp);
<------><------>return NULL;
<------>}
<------>dr->node.name = kstrdup_const("kmalloc", GFP_KERNEL);
 
<------>add_dr(dev, dr);
 
<------>return dr->data;
}
EXPORT_SYMBOL(drmm_kmalloc);
 
/**
 * drmm_kstrdup - &drm_device managed kstrdup()
 * @dev: DRM device
 * @s: 0-terminated string to be duplicated
 * @gfp: GFP allocation flags
 *
 * This is a &drm_device managed version of kstrdup(). The allocated memory is
 * automatically freed on the final drm_dev_put() and works exactly like a
 * memory allocation obtained by drmm_kmalloc().
 */
char *drmm_kstrdup(struct drm_device *dev, const char *s, gfp_t gfp)
{
<------>size_t size;
<------>char *buf;
 
<------>if (!s)
<------><------>return NULL;
 
<------>size = strlen(s) + 1;
<------>buf = drmm_kmalloc(dev, size, gfp);
<------>if (buf)
<------><------>memcpy(buf, s, size);
<------>return buf;
}
EXPORT_SYMBOL_GPL(drmm_kstrdup);
 
/**
 * drmm_kfree - &drm_device managed kfree()
 * @dev: DRM device
 * @data: memory allocation to be freed
 *
 * This is a &drm_device managed version of kfree() which can be used to
 * release memory allocated through drmm_kmalloc() or any of its related
 * functions before the final drm_dev_put() of @dev.
 */
void drmm_kfree(struct drm_device *dev, void *data)
{
<------>struct drmres *dr_match = NULL, *dr;
<------>unsigned long flags;
 
<------>if (!data)
<------><------>return;
 
<------>spin_lock_irqsave(&dev->managed.lock, flags);
<------>list_for_each_entry(dr, &dev->managed.resources, node.entry) {
<------><------>if (dr->data == data) {
<------><------><------>dr_match = dr;
<------><------><------>del_dr(dev, dr_match);
<------><------><------>break;
<------><------>}
<------>}
<------>spin_unlock_irqrestore(&dev->managed.lock, flags);
 
<------>if (WARN_ON(!dr_match))
<------><------>return;
 
<------>free_dr(dr_match);
}
EXPORT_SYMBOL(drmm_kfree);