diff options
Diffstat (limited to 'drivers/gpu/drm/drm_managed.c')
| -rw-r--r-- | drivers/gpu/drm/drm_managed.c | 53 |
1 files changed, 53 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_managed.c b/drivers/gpu/drm/drm_managed.c index 7246a8318137..4955241ceb4c 100644 --- a/drivers/gpu/drm/drm_managed.c +++ b/drivers/gpu/drm/drm_managed.c @@ -20,7 +20,19 @@ * 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 drm_dev_init(). + * + * 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; @@ -111,6 +123,18 @@ static void add_dr(struct drm_device *dev, struct drmres *dr) dr, dr->node.name, (unsigned long) dr->node.size); } +/** + * drmm_add_final_kfree - add release action for the final kfree() + * @dev: DRM device + * @container: pointer to the kmalloc allocation containing @dev + * + * Since the allocation containing the struct &drm_device must be allocated + * before it can be initialized with drm_dev_init() there's no way to allocate + * that memory with drmm_kmalloc(). To side-step this chicken-egg problem the + * pointer for this final kfree() must be specified by calling this function. It + * will be released in the final drm_dev_put() for @dev, after all other release + * actions installed through drmm_add_action() have been processed. + */ void drmm_add_final_kfree(struct drm_device *dev, void *container) { WARN_ON(dev->managed.final_kfree); @@ -163,6 +187,16 @@ int __drmm_add_action_or_reset(struct drm_device *dev, } 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; @@ -181,6 +215,16 @@ void *drmm_kmalloc(struct drm_device *dev, size_t size, gfp_t gfp) } 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; @@ -197,6 +241,15 @@ char *drmm_kstrdup(struct drm_device *dev, const char *s, gfp_t gfp) } 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; |