drm: add unified vma offset manager
If we want to map GPU memory into user-space, we need to linearize the addresses to not confuse mm-core. Currently, GEM and TTM both implement their own offset-managers to assign a pgoff to each object for user-space CPU access. GEM uses a hash-table, TTM uses an rbtree. This patch provides a unified implementation that can be used to replace both. TTM allows partial mmaps with a given offset, so we cannot use hashtables as the start address may not be known at mmap time. Hence, we use the rbtree-implementation of TTM. We could easily update drm_mm to use an rbtree instead of a linked list for it's object list and thus drop the rbtree from the vma-manager. However, this would slow down drm_mm object allocation for all other use-cases (rbtree insertion) and add another 4-8 bytes to each mm node. Hence, use the separate tree but allow for later migration. This is a rewrite of the 2012-proposal by David Airlie <airlied@linux.ie> v2: - fix Docbook integration - drop drm_mm_node_linked() and use drm_mm_node_allocated() - remove unjustified likely/unlikely usage (but keep for rbtree paths) - remove BUG_ON() as drm_mm already does that - clarify page-based vs. byte-based addresses - use drm_vma_node_reset() for initialization, too v4: - allow external locking via drm_vma_offset_un/lock_lookup() - add locked lookup helper drm_vma_offset_lookup_locked() v5: - fix drm_vma_offset_lookup() to correctly validate range-mismatches (fix (offset > start + pages)) - fix drm_vma_offset_exact_lookup() to actually do what it says - remove redundant vm_pages member (add drm_vma_node_size() helper) - remove unneeded goto - fix documentation Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Dave Airlie <airlied@gmail.com>
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				| @ -2212,6 +2212,12 @@ void intel_crt_init(struct drm_device *dev) | ||||
| !Iinclude/drm/drm_rect.h | ||||
| !Edrivers/gpu/drm/drm_rect.c | ||||
|     </sect2> | ||||
|     <sect2> | ||||
|       <title>VMA Offset Manager</title> | ||||
| !Pdrivers/gpu/drm/drm_vma_manager.c vma offset manager | ||||
| !Edrivers/gpu/drm/drm_vma_manager.c | ||||
| !Iinclude/drm/drm_vma_manager.h | ||||
|     </sect2> | ||||
|   </sect1> | ||||
| 
 | ||||
|   <!-- Internals: kms properties --> | ||||
|  | ||||
| @ -13,7 +13,7 @@ drm-y       :=	drm_auth.o drm_buffer.o drm_bufs.o drm_cache.o \ | ||||
| 		drm_crtc.o drm_modes.o drm_edid.o \
 | ||||
| 		drm_info.o drm_debugfs.o drm_encoder_slave.o \
 | ||||
| 		drm_trace_points.o drm_global.o drm_prime.o \
 | ||||
| 		drm_rect.o | ||||
| 		drm_rect.o drm_vma_manager.o | ||||
| 
 | ||||
| drm-$(CONFIG_COMPAT) += drm_ioc32.o | ||||
| drm-$(CONFIG_DRM_GEM_CMA_HELPER) += drm_gem_cma_helper.o | ||||
|  | ||||
							
								
								
									
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								drivers/gpu/drm/drm_vma_manager.c
									
									
									
									
									
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								drivers/gpu/drm/drm_vma_manager.c
									
									
									
									
									
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							| @ -0,0 +1,281 @@ | ||||
| /*
 | ||||
|  * Copyright (c) 2006-2009 VMware, Inc., Palo Alto, CA., USA | ||||
|  * Copyright (c) 2012 David Airlie <airlied@linux.ie> | ||||
|  * Copyright (c) 2013 David Herrmann <dh.herrmann@gmail.com> | ||||
|  * | ||||
|  * Permission is hereby granted, free of charge, to any person obtaining a | ||||
|  * copy of this software and associated documentation files (the "Software"), | ||||
|  * to deal in the Software without restriction, including without limitation | ||||
|  * the rights to use, copy, modify, merge, publish, distribute, sublicense, | ||||
|  * and/or sell copies of the Software, and to permit persons to whom the | ||||
|  * Software is furnished to do so, subject to the following conditions: | ||||
|  * | ||||
|  * The above copyright notice and this permission notice shall be included in | ||||
|  * all copies or substantial portions of the Software. | ||||
|  * | ||||
|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | ||||
|  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | ||||
|  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL | ||||
|  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR | ||||
|  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, | ||||
|  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | ||||
|  * OTHER DEALINGS IN THE SOFTWARE. | ||||
|  */ | ||||
| 
 | ||||
| #include <drm/drmP.h> | ||||
| #include <drm/drm_mm.h> | ||||
| #include <drm/drm_vma_manager.h> | ||||
| #include <linux/mm.h> | ||||
| #include <linux/module.h> | ||||
| #include <linux/rbtree.h> | ||||
| #include <linux/slab.h> | ||||
| #include <linux/spinlock.h> | ||||
| #include <linux/types.h> | ||||
| 
 | ||||
| /**
 | ||||
|  * DOC: vma offset manager | ||||
|  * | ||||
|  * The vma-manager is responsible to map arbitrary driver-dependent memory | ||||
|  * regions into the linear user address-space. It provides offsets to the | ||||
|  * caller which can then be used on the address_space of the drm-device. It | ||||
|  * takes care to not overlap regions, size them appropriately and to not | ||||
|  * confuse mm-core by inconsistent fake vm_pgoff fields. | ||||
|  * Drivers shouldn't use this for object placement in VMEM. This manager should | ||||
|  * only be used to manage mappings into linear user-space VMs. | ||||
|  * | ||||
|  * We use drm_mm as backend to manage object allocations. But it is highly | ||||
|  * optimized for alloc/free calls, not lookups. Hence, we use an rb-tree to | ||||
|  * speed up offset lookups. | ||||
|  * | ||||
|  * You must not use multiple offset managers on a single address_space. | ||||
|  * Otherwise, mm-core will be unable to tear down memory mappings as the VM will | ||||
|  * no longer be linear. Please use VM_NONLINEAR in that case and implement your | ||||
|  * own offset managers. | ||||
|  * | ||||
|  * This offset manager works on page-based addresses. That is, every argument | ||||
|  * and return code (with the exception of drm_vma_node_offset_addr()) is given | ||||
|  * in number of pages, not number of bytes. That means, object sizes and offsets | ||||
|  * must always be page-aligned (as usual). | ||||
|  * If you want to get a valid byte-based user-space address for a given offset, | ||||
|  * please see drm_vma_node_offset_addr(). | ||||
|  */ | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_offset_manager_init - Initialize new offset-manager | ||||
|  * @mgr: Manager object | ||||
|  * @page_offset: Offset of available memory area (page-based) | ||||
|  * @size: Size of available address space range (page-based) | ||||
|  * | ||||
|  * Initialize a new offset-manager. The offset and area size available for the | ||||
|  * manager are given as @page_offset and @size. Both are interpreted as | ||||
|  * page-numbers, not bytes. | ||||
|  * | ||||
|  * Adding/removing nodes from the manager is locked internally and protected | ||||
|  * against concurrent access. However, node allocation and destruction is left | ||||
|  * for the caller. While calling into the vma-manager, a given node must | ||||
|  * always be guaranteed to be referenced. | ||||
|  */ | ||||
| void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, | ||||
| 				 unsigned long page_offset, unsigned long size) | ||||
| { | ||||
| 	rwlock_init(&mgr->vm_lock); | ||||
| 	mgr->vm_addr_space_rb = RB_ROOT; | ||||
| 	drm_mm_init(&mgr->vm_addr_space_mm, page_offset, size); | ||||
| } | ||||
| EXPORT_SYMBOL(drm_vma_offset_manager_init); | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_offset_manager_destroy() - Destroy offset manager | ||||
|  * @mgr: Manager object | ||||
|  * | ||||
|  * Destroy an object manager which was previously created via | ||||
|  * drm_vma_offset_manager_init(). The caller must remove all allocated nodes | ||||
|  * before destroying the manager. Otherwise, drm_mm will refuse to free the | ||||
|  * requested resources. | ||||
|  * | ||||
|  * The manager must not be accessed after this function is called. | ||||
|  */ | ||||
| void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr) | ||||
| { | ||||
| 	/* take the lock to protect against buggy drivers */ | ||||
| 	write_lock(&mgr->vm_lock); | ||||
| 	drm_mm_takedown(&mgr->vm_addr_space_mm); | ||||
| 	write_unlock(&mgr->vm_lock); | ||||
| } | ||||
| EXPORT_SYMBOL(drm_vma_offset_manager_destroy); | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_offset_lookup() - Find node in offset space | ||||
|  * @mgr: Manager object | ||||
|  * @start: Start address for object (page-based) | ||||
|  * @pages: Size of object (page-based) | ||||
|  * | ||||
|  * Find a node given a start address and object size. This returns the _best_ | ||||
|  * match for the given node. That is, @start may point somewhere into a valid | ||||
|  * region and the given node will be returned, as long as the node spans the | ||||
|  * whole requested area (given the size in number of pages as @pages). | ||||
|  * | ||||
|  * RETURNS: | ||||
|  * Returns NULL if no suitable node can be found. Otherwise, the best match | ||||
|  * is returned. It's the caller's responsibility to make sure the node doesn't | ||||
|  * get destroyed before the caller can access it. | ||||
|  */ | ||||
| struct drm_vma_offset_node *drm_vma_offset_lookup(struct drm_vma_offset_manager *mgr, | ||||
| 						  unsigned long start, | ||||
| 						  unsigned long pages) | ||||
| { | ||||
| 	struct drm_vma_offset_node *node; | ||||
| 
 | ||||
| 	read_lock(&mgr->vm_lock); | ||||
| 	node = drm_vma_offset_lookup_locked(mgr, start, pages); | ||||
| 	read_unlock(&mgr->vm_lock); | ||||
| 
 | ||||
| 	return node; | ||||
| } | ||||
| EXPORT_SYMBOL(drm_vma_offset_lookup); | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_offset_lookup_locked() - Find node in offset space | ||||
|  * @mgr: Manager object | ||||
|  * @start: Start address for object (page-based) | ||||
|  * @pages: Size of object (page-based) | ||||
|  * | ||||
|  * Same as drm_vma_offset_lookup() but requires the caller to lock offset lookup | ||||
|  * manually. See drm_vma_offset_lock_lookup() for an example. | ||||
|  * | ||||
|  * RETURNS: | ||||
|  * Returns NULL if no suitable node can be found. Otherwise, the best match | ||||
|  * is returned. | ||||
|  */ | ||||
| struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, | ||||
| 							 unsigned long start, | ||||
| 							 unsigned long pages) | ||||
| { | ||||
| 	struct drm_vma_offset_node *node, *best; | ||||
| 	struct rb_node *iter; | ||||
| 	unsigned long offset; | ||||
| 
 | ||||
| 	iter = mgr->vm_addr_space_rb.rb_node; | ||||
| 	best = NULL; | ||||
| 
 | ||||
| 	while (likely(iter)) { | ||||
| 		node = rb_entry(iter, struct drm_vma_offset_node, vm_rb); | ||||
| 		offset = node->vm_node.start; | ||||
| 		if (start >= offset) { | ||||
| 			iter = iter->rb_right; | ||||
| 			best = node; | ||||
| 			if (start == offset) | ||||
| 				break; | ||||
| 		} else { | ||||
| 			iter = iter->rb_left; | ||||
| 		} | ||||
| 	} | ||||
| 
 | ||||
| 	/* verify that the node spans the requested area */ | ||||
| 	if (best) { | ||||
| 		offset = best->vm_node.start + best->vm_node.size; | ||||
| 		if (offset < start + pages) | ||||
| 			best = NULL; | ||||
| 	} | ||||
| 
 | ||||
| 	return best; | ||||
| } | ||||
| EXPORT_SYMBOL(drm_vma_offset_lookup_locked); | ||||
| 
 | ||||
| /* internal helper to link @node into the rb-tree */ | ||||
| static void _drm_vma_offset_add_rb(struct drm_vma_offset_manager *mgr, | ||||
| 				   struct drm_vma_offset_node *node) | ||||
| { | ||||
| 	struct rb_node **iter = &mgr->vm_addr_space_rb.rb_node; | ||||
| 	struct rb_node *parent = NULL; | ||||
| 	struct drm_vma_offset_node *iter_node; | ||||
| 
 | ||||
| 	while (likely(*iter)) { | ||||
| 		parent = *iter; | ||||
| 		iter_node = rb_entry(*iter, struct drm_vma_offset_node, vm_rb); | ||||
| 
 | ||||
| 		if (node->vm_node.start < iter_node->vm_node.start) | ||||
| 			iter = &(*iter)->rb_left; | ||||
| 		else if (node->vm_node.start > iter_node->vm_node.start) | ||||
| 			iter = &(*iter)->rb_right; | ||||
| 		else | ||||
| 			BUG(); | ||||
| 	} | ||||
| 
 | ||||
| 	rb_link_node(&node->vm_rb, parent, iter); | ||||
| 	rb_insert_color(&node->vm_rb, &mgr->vm_addr_space_rb); | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_offset_add() - Add offset node to manager | ||||
|  * @mgr: Manager object | ||||
|  * @node: Node to be added | ||||
|  * @pages: Allocation size visible to user-space (in number of pages) | ||||
|  * | ||||
|  * Add a node to the offset-manager. If the node was already added, this does | ||||
|  * nothing and return 0. @pages is the size of the object given in number of | ||||
|  * pages. | ||||
|  * After this call succeeds, you can access the offset of the node until it | ||||
|  * is removed again. | ||||
|  * | ||||
|  * If this call fails, it is safe to retry the operation or call | ||||
|  * drm_vma_offset_remove(), anyway. However, no cleanup is required in that | ||||
|  * case. | ||||
|  * | ||||
|  * @pages is not required to be the same size as the underlying memory object | ||||
|  * that you want to map. It only limits the size that user-space can map into | ||||
|  * their address space. | ||||
|  * | ||||
|  * RETURNS: | ||||
|  * 0 on success, negative error code on failure. | ||||
|  */ | ||||
| int drm_vma_offset_add(struct drm_vma_offset_manager *mgr, | ||||
| 		       struct drm_vma_offset_node *node, unsigned long pages) | ||||
| { | ||||
| 	int ret; | ||||
| 
 | ||||
| 	write_lock(&mgr->vm_lock); | ||||
| 
 | ||||
| 	if (drm_mm_node_allocated(&node->vm_node)) { | ||||
| 		ret = 0; | ||||
| 		goto out_unlock; | ||||
| 	} | ||||
| 
 | ||||
| 	ret = drm_mm_insert_node_generic(&mgr->vm_addr_space_mm, | ||||
| 					 &node->vm_node, pages, 0, 0); | ||||
| 	if (ret) | ||||
| 		goto out_unlock; | ||||
| 
 | ||||
| 	_drm_vma_offset_add_rb(mgr, node); | ||||
| 
 | ||||
| out_unlock: | ||||
| 	write_unlock(&mgr->vm_lock); | ||||
| 	return ret; | ||||
| } | ||||
| EXPORT_SYMBOL(drm_vma_offset_add); | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_offset_remove() - Remove offset node from manager | ||||
|  * @mgr: Manager object | ||||
|  * @node: Node to be removed | ||||
|  * | ||||
|  * Remove a node from the offset manager. If the node wasn't added before, this | ||||
|  * does nothing. After this call returns, the offset and size will be 0 until a | ||||
|  * new offset is allocated via drm_vma_offset_add() again. Helper functions like | ||||
|  * drm_vma_node_start() and drm_vma_node_offset_addr() will return 0 if no | ||||
|  * offset is allocated. | ||||
|  */ | ||||
| void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, | ||||
| 			   struct drm_vma_offset_node *node) | ||||
| { | ||||
| 	write_lock(&mgr->vm_lock); | ||||
| 
 | ||||
| 	if (drm_mm_node_allocated(&node->vm_node)) { | ||||
| 		rb_erase(&node->vm_rb, &mgr->vm_addr_space_rb); | ||||
| 		drm_mm_remove_node(&node->vm_node); | ||||
| 		memset(&node->vm_node, 0, sizeof(node->vm_node)); | ||||
| 	} | ||||
| 
 | ||||
| 	write_unlock(&mgr->vm_lock); | ||||
| } | ||||
| EXPORT_SYMBOL(drm_vma_offset_remove); | ||||
							
								
								
									
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								include/drm/drm_vma_manager.h
									
									
									
									
									
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								include/drm/drm_vma_manager.h
									
									
									
									
									
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							| @ -0,0 +1,202 @@ | ||||
| #ifndef __DRM_VMA_MANAGER_H__ | ||||
| #define __DRM_VMA_MANAGER_H__ | ||||
| 
 | ||||
| /*
 | ||||
|  * Copyright (c) 2013 David Herrmann <dh.herrmann@gmail.com> | ||||
|  * | ||||
|  * Permission is hereby granted, free of charge, to any person obtaining a | ||||
|  * copy of this software and associated documentation files (the "Software"), | ||||
|  * to deal in the Software without restriction, including without limitation | ||||
|  * the rights to use, copy, modify, merge, publish, distribute, sublicense, | ||||
|  * and/or sell copies of the Software, and to permit persons to whom the | ||||
|  * Software is furnished to do so, subject to the following conditions: | ||||
|  * | ||||
|  * The above copyright notice and this permission notice shall be included in | ||||
|  * all copies or substantial portions of the Software. | ||||
|  * | ||||
|  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | ||||
|  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | ||||
|  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL | ||||
|  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR | ||||
|  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, | ||||
|  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | ||||
|  * OTHER DEALINGS IN THE SOFTWARE. | ||||
|  */ | ||||
| 
 | ||||
| #include <drm/drm_mm.h> | ||||
| #include <linux/module.h> | ||||
| #include <linux/rbtree.h> | ||||
| #include <linux/spinlock.h> | ||||
| #include <linux/types.h> | ||||
| 
 | ||||
| struct drm_vma_offset_node { | ||||
| 	struct drm_mm_node vm_node; | ||||
| 	struct rb_node vm_rb; | ||||
| }; | ||||
| 
 | ||||
| struct drm_vma_offset_manager { | ||||
| 	rwlock_t vm_lock; | ||||
| 	struct rb_root vm_addr_space_rb; | ||||
| 	struct drm_mm vm_addr_space_mm; | ||||
| }; | ||||
| 
 | ||||
| void drm_vma_offset_manager_init(struct drm_vma_offset_manager *mgr, | ||||
| 				 unsigned long page_offset, unsigned long size); | ||||
| void drm_vma_offset_manager_destroy(struct drm_vma_offset_manager *mgr); | ||||
| 
 | ||||
| struct drm_vma_offset_node *drm_vma_offset_lookup(struct drm_vma_offset_manager *mgr, | ||||
| 						  unsigned long start, | ||||
| 						  unsigned long pages); | ||||
| struct drm_vma_offset_node *drm_vma_offset_lookup_locked(struct drm_vma_offset_manager *mgr, | ||||
| 							   unsigned long start, | ||||
| 							   unsigned long pages); | ||||
| int drm_vma_offset_add(struct drm_vma_offset_manager *mgr, | ||||
| 		       struct drm_vma_offset_node *node, unsigned long pages); | ||||
| void drm_vma_offset_remove(struct drm_vma_offset_manager *mgr, | ||||
| 			   struct drm_vma_offset_node *node); | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_offset_exact_lookup() - Look up node by exact address | ||||
|  * @mgr: Manager object | ||||
|  * @start: Start address (page-based, not byte-based) | ||||
|  * @pages: Size of object (page-based) | ||||
|  * | ||||
|  * Same as drm_vma_offset_lookup() but does not allow any offset into the node. | ||||
|  * It only returns the exact object with the given start address. | ||||
|  * | ||||
|  * RETURNS: | ||||
|  * Node at exact start address @start. | ||||
|  */ | ||||
| static inline struct drm_vma_offset_node * | ||||
| drm_vma_offset_exact_lookup(struct drm_vma_offset_manager *mgr, | ||||
| 			    unsigned long start, | ||||
| 			    unsigned long pages) | ||||
| { | ||||
| 	struct drm_vma_offset_node *node; | ||||
| 
 | ||||
| 	node = drm_vma_offset_lookup(mgr, start, pages); | ||||
| 	return (node && node->vm_node.start == start) ? node : NULL; | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_offset_lock_lookup() - Lock lookup for extended private use | ||||
|  * @mgr: Manager object | ||||
|  * | ||||
|  * Lock VMA manager for extended lookups. Only *_locked() VMA function calls | ||||
|  * are allowed while holding this lock. All other contexts are blocked from VMA | ||||
|  * until the lock is released via drm_vma_offset_unlock_lookup(). | ||||
|  * | ||||
|  * Use this if you need to take a reference to the objects returned by | ||||
|  * drm_vma_offset_lookup_locked() before releasing this lock again. | ||||
|  * | ||||
|  * This lock must not be used for anything else than extended lookups. You must | ||||
|  * not call any other VMA helpers while holding this lock. | ||||
|  * | ||||
|  * Note: You're in atomic-context while holding this lock! | ||||
|  * | ||||
|  * Example: | ||||
|  *   drm_vma_offset_lock_lookup(mgr); | ||||
|  *   node = drm_vma_offset_lookup_locked(mgr); | ||||
|  *   if (node) | ||||
|  *       kref_get_unless_zero(container_of(node, sth, entr)); | ||||
|  *   drm_vma_offset_unlock_lookup(mgr); | ||||
|  */ | ||||
| static inline void drm_vma_offset_lock_lookup(struct drm_vma_offset_manager *mgr) | ||||
| { | ||||
| 	read_lock(&mgr->vm_lock); | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_offset_unlock_lookup() - Unlock lookup for extended private use | ||||
|  * @mgr: Manager object | ||||
|  * | ||||
|  * Release lookup-lock. See drm_vma_offset_lock_lookup() for more information. | ||||
|  */ | ||||
| static inline void drm_vma_offset_unlock_lookup(struct drm_vma_offset_manager *mgr) | ||||
| { | ||||
| 	read_unlock(&mgr->vm_lock); | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_node_reset() - Initialize or reset node object | ||||
|  * @node: Node to initialize or reset | ||||
|  * | ||||
|  * Reset a node to its initial state. This must be called if @node isn't | ||||
|  * already cleared (eg., via kzalloc) before using it with any VMA offset | ||||
|  * manager. | ||||
|  * | ||||
|  * This must not be called on an already allocated node, or you will leak | ||||
|  * memory. | ||||
|  */ | ||||
| static inline void drm_vma_node_reset(struct drm_vma_offset_node *node) | ||||
| { | ||||
| 	memset(node, 0, sizeof(*node)); | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_node_start() - Return start address for page-based addressing | ||||
|  * @node: Node to inspect | ||||
|  * | ||||
|  * Return the start address of the given node. This can be used as offset into | ||||
|  * the linear VM space that is provided by the VMA offset manager. Note that | ||||
|  * this can only be used for page-based addressing. If you need a proper offset | ||||
|  * for user-space mappings, you must apply "<< PAGE_SHIFT" or use the | ||||
|  * drm_vma_node_offset_addr() helper instead. | ||||
|  * | ||||
|  * RETURNS: | ||||
|  * Start address of @node for page-based addressing. 0 if the node does not | ||||
|  * have an offset allocated. | ||||
|  */ | ||||
| static inline unsigned long drm_vma_node_start(struct drm_vma_offset_node *node) | ||||
| { | ||||
| 	return node->vm_node.start; | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_node_size() - Return size (page-based) | ||||
|  * @node: Node to inspect | ||||
|  * | ||||
|  * Return the size as number of pages for the given node. This is the same size | ||||
|  * that was passed to drm_vma_offset_add(). If no offset is allocated for the | ||||
|  * node, this is 0. | ||||
|  * | ||||
|  * RETURNS: | ||||
|  * Size of @node as number of pages. 0 if the node does not have an offset | ||||
|  * allocated. | ||||
|  */ | ||||
| static inline unsigned long drm_vma_node_size(struct drm_vma_offset_node *node) | ||||
| { | ||||
| 	return node->vm_node.size; | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_node_has_offset() - Check whether node is added to offset manager | ||||
|  * @node: Node to be checked | ||||
|  * | ||||
|  * RETURNS: | ||||
|  * true iff the node was previously allocated an offset and added to | ||||
|  * an vma offset manager. | ||||
|  */ | ||||
| static inline bool drm_vma_node_has_offset(struct drm_vma_offset_node *node) | ||||
| { | ||||
| 	return drm_mm_node_allocated(&node->vm_node); | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  * drm_vma_node_offset_addr() - Return sanitized offset for user-space mmaps | ||||
|  * @node: Linked offset node | ||||
|  * | ||||
|  * Same as drm_vma_node_start() but returns the address as a valid offset that | ||||
|  * can be used for user-space mappings during mmap(). | ||||
|  * This must not be called on unlinked nodes. | ||||
|  * | ||||
|  * RETURNS: | ||||
|  * Offset of @node for byte-based addressing. 0 if the node does not have an | ||||
|  * object allocated. | ||||
|  */ | ||||
| static inline __u64 drm_vma_node_offset_addr(struct drm_vma_offset_node *node) | ||||
| { | ||||
| 	return ((__u64)node->vm_node.start) << PAGE_SHIFT; | ||||
| } | ||||
| 
 | ||||
| #endif /* __DRM_VMA_MANAGER_H__ */ | ||||
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