// SPDX-License-Identifier: GPL-2.0/* * Copyright (C) 2020 Intel * * Based on drivers/base/devres.c */ #include <drm/drm_managed.h> #include <linux/export.h>#include <linux/list.h>#include <linux/mutex.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_DMA_MINALIGN for data[] which will force the same	 * alignment for struct drmres when allocated by kmalloc().	 */	u8 __aligned(ARCH_DMA_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_release_action - release a managed action from a &drm_device * @dev: DRM device * @action: function which would be called when @dev is released * @data: opaque pointer, passed to @action * * This function calls the @action previously added by drmm_add_action() * immediately. * The @action is removed from the list of cleanup actions for @dev, * which means that it won't be called in the final drm_dev_put(). */void drmm_release_action(struct drm_device *dev,			 drmres_release_t action,			 void *data){	struct drmres *dr_match = NULL, *dr;	unsigned long flags; 	spin_lock_irqsave(&dev->managed.lock, flags);	list_for_each_entry_reverse(dr, &dev->managed.resources, node.entry) {		if (dr->node.release == action) {			if (!data || *(void **)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; 	action(dev, data); 	free_dr(dr_match);}EXPORT_SYMBOL(drmm_release_action); /** * 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, %pGg\n",			       size, &gfp);		return NULL;	}	dr->node.name = kstrdup_const("kmalloc", gfp); 	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); void __drmm_mutex_release(struct drm_device *dev, void *res){	struct mutex *lock = res; 	mutex_destroy(lock);}EXPORT_SYMBOL(__drmm_mutex_release); void __drmm_workqueue_release(struct drm_device *device, void *res){	struct workqueue_struct *wq = res; 	destroy_workqueue(wq);}EXPORT_SYMBOL(__drmm_workqueue_release);