// SPDX-License-Identifier: GPL-2.0

#ifndef _DRM_MANAGED_H_
#define _DRM_MANAGED_H_

#include <linux/device.h>
#include <linux/gfp.h>
#include <linux/overflow.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <drm/drm_device.h>

struct drm_device;
struct mutex;

typedef void (*drmres_release_t)(struct drm_device *dev, void *res);

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_DMA_MINALIGN for data[] which will force the same
     * alignment for struct drmres when allocated by kmalloc().
     */
    u8 __aligned(ARCH_DMA_MINALIGN) data[];
};

/**
 * drmm_add_action - add a managed release action to a &drm_device
 * @dev: DRM device
 * @action: function which should be called when @dev is released
 * @data: opaque pointer, passed to @action
 *
 * This function adds the @release action with optional parameter @data to the
 * list of cleanup actions for @dev. The cleanup actions will be run in reverse
 * order in the final drm_dev_put() call for @dev.
 */
#define drmm_add_action(dev, action, data) \
    __drmm_add_action(dev, action, data, #action)

int __must_check __drmm_add_action(struct drm_device *dev,
                   drmres_release_t action,
                   void *data, const char *name);

/**
 * drmm_add_action_or_reset - add a managed release action to a &drm_device
 * @dev: DRM device
 * @action: function which should be called when @dev is released
 * @data: opaque pointer, passed to @action
 *
 * Similar to drmm_add_action(), with the only difference that upon failure
 * @action is directly called for any cleanup work necessary on failures.
 */
#define drmm_add_action_or_reset(dev, action, data) \
    __drmm_add_action_or_reset(dev, action, data, #action)

int __must_check __drmm_add_action_or_reset(struct drm_device *dev,
                        drmres_release_t action,
                        void *data, const char *name);

/*
 * Always inline so that __kmalloc_track_caller tracks the actual interesting
 * caller outside of drm_managed.h.
 */
static __always_inline struct drmres * drmm_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;
}

void *__drmm_kmalloc(struct drm_device *dev, size_t size, gfp_t gfp, struct drmres *dr);

static __always_inline __malloc __alloc_gfp_flags(3)
void *drmm_kmalloc(struct drm_device *dev, size_t size, gfp_t gfp)
{
    return __drmm_kmalloc(dev, size, gfp, drmm_alloc_dr(NULL, size, gfp, dev_to_node(dev->dev)));
}

/**
 * drmm_kzalloc - &drm_device managed kzalloc()
 * @dev: DRM device
 * @size: size of the memory allocation
 * @gfp: GFP allocation flags
 *
 * This is a &drm_device managed version of kzalloc(). 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().
 */
static inline void *drmm_kzalloc(struct drm_device *dev, size_t size, gfp_t gfp)
{
    return drmm_kmalloc(dev, size, gfp | __GFP_ZERO);
}

/**
 * drmm_kmalloc_array - &drm_device managed kmalloc_array()
 * @dev: DRM device
 * @n: number of array elements to allocate
 * @size: size of array member
 * @flags: GFP allocation flags
 *
 * This is a &drm_device managed version of kmalloc_array(). The allocated
 * memory is automatically freed on the final drm_dev_put() and works exactly
 * like a memory allocation obtained by drmm_kmalloc().
 */
static inline void *drmm_kmalloc_array(struct drm_device *dev,
                       size_t n, size_t size, gfp_t flags)
{
    size_t bytes;

    if (unlikely(check_mul_overflow(n, size, &bytes)))
        return NULL;

    return drmm_kmalloc(dev, bytes, flags);
}

/**
 * drmm_kcalloc - &drm_device managed kcalloc()
 * @dev: DRM device
 * @n: number of array elements to allocate
 * @size: size of array member
 * @flags: GFP allocation flags
 *
 * This is a &drm_device managed version of kcalloc(). The allocated memory is
 * automatically freed on the final drm_dev_put() and works exactly like a
 * memory allocation obtained by drmm_kmalloc().
 */
static inline void *drmm_kcalloc(struct drm_device *dev,
                 size_t n, size_t size, gfp_t flags)
{
    return drmm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
}

char *drmm_kstrdup(struct drm_device *dev, const char *s, gfp_t gfp);

void drmm_kfree(struct drm_device *dev, void *data);

void __drmm_mutex_release(struct drm_device *dev, void *res);

/**
 * drmm_mutex_init - &drm_device-managed mutex_init()
 * @dev: DRM device
 * @lock: lock to be initialized
 *
 * Returns:
 * 0 on success, or a negative errno code otherwise.
 *
 * This is a &drm_device-managed version of mutex_init(). The initialized
 * lock is automatically destroyed on the final drm_dev_put().
 */
#define drmm_mutex_init(dev, lock) ({                         \
    mutex_init(lock);                             \
    drmm_add_action_or_reset(dev, __drmm_mutex_release, lock);         \
})                                         \

#endif