linux/include/drm/drm_gem.h
Thomas Zimmermann b4b0193e83 drm/fbdev-generic: Fix locking with drm_client_buffer_vmap_local()
Temporarily lock the fbdev buffer object during updates to prevent
memory managers from evicting/moving the buffer. Moving a buffer
object while update its content results in undefined behaviour.

Fbdev-generic updates its buffer object from a shadow buffer. Gem-shmem
and gem-dma helpers do not move buffer objects, so they are safe to be
used with fbdev-generic. Gem-vram and qxl are based on TTM, but pin
buffer objects are part of the vmap operation. So both are also safe
to be used with fbdev-generic.

Amdgpu and nouveau do not pin or lock the buffer object during an
update. Their TTM-based memory management could move the buffer object
while the update is ongoing.

The new vmap_local and vunmap_local helpers hold the buffer object's
reservation lock during the buffer update. This prevents moving the
buffer object on all memory managers.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Tested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> # virtio-gpu
Acked-by: Zack Rusin <zack.rusin@broadcom.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240227113853.8464-11-tzimmermann@suse.de
2024-03-11 13:33:50 +01:00

637 lines
18 KiB
C

#ifndef __DRM_GEM_H__
#define __DRM_GEM_H__
/*
* GEM Graphics Execution Manager Driver Interfaces
*
* Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
* Copyright (c) 2009-2010, Code Aurora Forum.
* All rights reserved.
* Copyright © 2014 Intel Corporation
* Daniel Vetter <daniel.vetter@ffwll.ch>
*
* Author: Rickard E. (Rik) Faith <faith@valinux.com>
* Author: Gareth Hughes <gareth@valinux.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 (including the next
* paragraph) 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
* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS 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 <linux/kref.h>
#include <linux/dma-resv.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <drm/drm_vma_manager.h>
struct iosys_map;
struct drm_gem_object;
/**
* enum drm_gem_object_status - bitmask of object state for fdinfo reporting
* @DRM_GEM_OBJECT_RESIDENT: object is resident in memory (ie. not unpinned)
* @DRM_GEM_OBJECT_PURGEABLE: object marked as purgeable by userspace
*
* Bitmask of status used for fdinfo memory stats, see &drm_gem_object_funcs.status
* and drm_show_fdinfo(). Note that an object can DRM_GEM_OBJECT_PURGEABLE if
* it still active or not resident, in which case drm_show_fdinfo() will not
* account for it as purgeable. So drivers do not need to check if the buffer
* is idle and resident to return this bit. (Ie. userspace can mark a buffer
* as purgeable even while it is still busy on the GPU.. it does not _actually_
* become puregeable until it becomes idle. The status gem object func does
* not need to consider this.)
*/
enum drm_gem_object_status {
DRM_GEM_OBJECT_RESIDENT = BIT(0),
DRM_GEM_OBJECT_PURGEABLE = BIT(1),
};
/**
* struct drm_gem_object_funcs - GEM object functions
*/
struct drm_gem_object_funcs {
/**
* @free:
*
* Deconstructor for drm_gem_objects.
*
* This callback is mandatory.
*/
void (*free)(struct drm_gem_object *obj);
/**
* @open:
*
* Called upon GEM handle creation.
*
* This callback is optional.
*/
int (*open)(struct drm_gem_object *obj, struct drm_file *file);
/**
* @close:
*
* Called upon GEM handle release.
*
* This callback is optional.
*/
void (*close)(struct drm_gem_object *obj, struct drm_file *file);
/**
* @print_info:
*
* If driver subclasses struct &drm_gem_object, it can implement this
* optional hook for printing additional driver specific info.
*
* drm_printf_indent() should be used in the callback passing it the
* indent argument.
*
* This callback is called from drm_gem_print_info().
*
* This callback is optional.
*/
void (*print_info)(struct drm_printer *p, unsigned int indent,
const struct drm_gem_object *obj);
/**
* @export:
*
* Export backing buffer as a &dma_buf.
* If this is not set drm_gem_prime_export() is used.
*
* This callback is optional.
*/
struct dma_buf *(*export)(struct drm_gem_object *obj, int flags);
/**
* @pin:
*
* Pin backing buffer in memory. Used by the drm_gem_map_attach() helper.
*
* This callback is optional.
*/
int (*pin)(struct drm_gem_object *obj);
/**
* @unpin:
*
* Unpin backing buffer. Used by the drm_gem_map_detach() helper.
*
* This callback is optional.
*/
void (*unpin)(struct drm_gem_object *obj);
/**
* @get_sg_table:
*
* Returns a Scatter-Gather table representation of the buffer.
* Used when exporting a buffer by the drm_gem_map_dma_buf() helper.
* Releasing is done by calling dma_unmap_sg_attrs() and sg_free_table()
* in drm_gem_unmap_buf(), therefore these helpers and this callback
* here cannot be used for sg tables pointing at driver private memory
* ranges.
*
* See also drm_prime_pages_to_sg().
*/
struct sg_table *(*get_sg_table)(struct drm_gem_object *obj);
/**
* @vmap:
*
* Returns a virtual address for the buffer. Used by the
* drm_gem_dmabuf_vmap() helper.
*
* This callback is optional.
*/
int (*vmap)(struct drm_gem_object *obj, struct iosys_map *map);
/**
* @vunmap:
*
* Releases the address previously returned by @vmap. Used by the
* drm_gem_dmabuf_vunmap() helper.
*
* This callback is optional.
*/
void (*vunmap)(struct drm_gem_object *obj, struct iosys_map *map);
/**
* @mmap:
*
* Handle mmap() of the gem object, setup vma accordingly.
*
* This callback is optional.
*
* The callback is used by both drm_gem_mmap_obj() and
* drm_gem_prime_mmap(). When @mmap is present @vm_ops is not
* used, the @mmap callback must set vma->vm_ops instead.
*/
int (*mmap)(struct drm_gem_object *obj, struct vm_area_struct *vma);
/**
* @evict:
*
* Evicts gem object out from memory. Used by the drm_gem_object_evict()
* helper. Returns 0 on success, -errno otherwise.
*
* This callback is optional.
*/
int (*evict)(struct drm_gem_object *obj);
/**
* @status:
*
* The optional status callback can return additional object state
* which determines which stats the object is counted against. The
* callback is called under table_lock. Racing against object status
* change is "harmless", and the callback can expect to not race
* against object destruction.
*
* Called by drm_show_memory_stats().
*/
enum drm_gem_object_status (*status)(struct drm_gem_object *obj);
/**
* @rss:
*
* Return resident size of the object in physical memory.
*
* Called by drm_show_memory_stats().
*/
size_t (*rss)(struct drm_gem_object *obj);
/**
* @vm_ops:
*
* Virtual memory operations used with mmap.
*
* This is optional but necessary for mmap support.
*/
const struct vm_operations_struct *vm_ops;
};
/**
* struct drm_gem_lru - A simple LRU helper
*
* A helper for tracking GEM objects in a given state, to aid in
* driver's shrinker implementation. Tracks the count of pages
* for lockless &shrinker.count_objects, and provides
* &drm_gem_lru_scan for driver's &shrinker.scan_objects
* implementation.
*/
struct drm_gem_lru {
/**
* @lock:
*
* Lock protecting movement of GEM objects between LRUs. All
* LRUs that the object can move between should be protected
* by the same lock.
*/
struct mutex *lock;
/**
* @count:
*
* The total number of backing pages of the GEM objects in
* this LRU.
*/
long count;
/**
* @list:
*
* The LRU list.
*/
struct list_head list;
};
/**
* struct drm_gem_object - GEM buffer object
*
* This structure defines the generic parts for GEM buffer objects, which are
* mostly around handling mmap and userspace handles.
*
* Buffer objects are often abbreviated to BO.
*/
struct drm_gem_object {
/**
* @refcount:
*
* Reference count of this object
*
* Please use drm_gem_object_get() to acquire and drm_gem_object_put_locked()
* or drm_gem_object_put() to release a reference to a GEM
* buffer object.
*/
struct kref refcount;
/**
* @handle_count:
*
* This is the GEM file_priv handle count of this object.
*
* Each handle also holds a reference. Note that when the handle_count
* drops to 0 any global names (e.g. the id in the flink namespace) will
* be cleared.
*
* Protected by &drm_device.object_name_lock.
*/
unsigned handle_count;
/**
* @dev: DRM dev this object belongs to.
*/
struct drm_device *dev;
/**
* @filp:
*
* SHMEM file node used as backing storage for swappable buffer objects.
* GEM also supports driver private objects with driver-specific backing
* storage (contiguous DMA memory, special reserved blocks). In this
* case @filp is NULL.
*/
struct file *filp;
/**
* @vma_node:
*
* Mapping info for this object to support mmap. Drivers are supposed to
* allocate the mmap offset using drm_gem_create_mmap_offset(). The
* offset itself can be retrieved using drm_vma_node_offset_addr().
*
* Memory mapping itself is handled by drm_gem_mmap(), which also checks
* that userspace is allowed to access the object.
*/
struct drm_vma_offset_node vma_node;
/**
* @size:
*
* Size of the object, in bytes. Immutable over the object's
* lifetime.
*/
size_t size;
/**
* @name:
*
* Global name for this object, starts at 1. 0 means unnamed.
* Access is covered by &drm_device.object_name_lock. This is used by
* the GEM_FLINK and GEM_OPEN ioctls.
*/
int name;
/**
* @dma_buf:
*
* dma-buf associated with this GEM object.
*
* Pointer to the dma-buf associated with this gem object (either
* through importing or exporting). We break the resulting reference
* loop when the last gem handle for this object is released.
*
* Protected by &drm_device.object_name_lock.
*/
struct dma_buf *dma_buf;
/**
* @import_attach:
*
* dma-buf attachment backing this object.
*
* Any foreign dma_buf imported as a gem object has this set to the
* attachment point for the device. This is invariant over the lifetime
* of a gem object.
*
* The &drm_gem_object_funcs.free callback is responsible for
* cleaning up the dma_buf attachment and references acquired at import
* time.
*
* Note that the drm gem/prime core does not depend upon drivers setting
* this field any more. So for drivers where this doesn't make sense
* (e.g. virtual devices or a displaylink behind an usb bus) they can
* simply leave it as NULL.
*/
struct dma_buf_attachment *import_attach;
/**
* @resv:
*
* Pointer to reservation object associated with the this GEM object.
*
* Normally (@resv == &@_resv) except for imported GEM objects.
*/
struct dma_resv *resv;
/**
* @_resv:
*
* A reservation object for this GEM object.
*
* This is unused for imported GEM objects.
*/
struct dma_resv _resv;
/**
* @gpuva:
*
* Provides the list of GPU VAs attached to this GEM object.
*
* Drivers should lock list accesses with the GEMs &dma_resv lock
* (&drm_gem_object.resv) or a custom lock if one is provided.
*/
struct {
struct list_head list;
#ifdef CONFIG_LOCKDEP
struct lockdep_map *lock_dep_map;
#endif
} gpuva;
/**
* @funcs:
*
* Optional GEM object functions. If this is set, it will be used instead of the
* corresponding &drm_driver GEM callbacks.
*
* New drivers should use this.
*
*/
const struct drm_gem_object_funcs *funcs;
/**
* @lru_node:
*
* List node in a &drm_gem_lru.
*/
struct list_head lru_node;
/**
* @lru:
*
* The current LRU list that the GEM object is on.
*/
struct drm_gem_lru *lru;
};
/**
* DRM_GEM_FOPS - Default drm GEM file operations
*
* This macro provides a shorthand for setting the GEM file ops in the
* &file_operations structure. If all you need are the default ops, use
* DEFINE_DRM_GEM_FOPS instead.
*/
#define DRM_GEM_FOPS \
.open = drm_open,\
.release = drm_release,\
.unlocked_ioctl = drm_ioctl,\
.compat_ioctl = drm_compat_ioctl,\
.poll = drm_poll,\
.read = drm_read,\
.llseek = noop_llseek,\
.mmap = drm_gem_mmap
/**
* DEFINE_DRM_GEM_FOPS() - macro to generate file operations for GEM drivers
* @name: name for the generated structure
*
* This macro autogenerates a suitable &struct file_operations for GEM based
* drivers, which can be assigned to &drm_driver.fops. Note that this structure
* cannot be shared between drivers, because it contains a reference to the
* current module using THIS_MODULE.
*
* Note that the declaration is already marked as static - if you need a
* non-static version of this you're probably doing it wrong and will break the
* THIS_MODULE reference by accident.
*/
#define DEFINE_DRM_GEM_FOPS(name) \
static const struct file_operations name = {\
.owner = THIS_MODULE,\
DRM_GEM_FOPS,\
}
void drm_gem_object_release(struct drm_gem_object *obj);
void drm_gem_object_free(struct kref *kref);
int drm_gem_object_init(struct drm_device *dev,
struct drm_gem_object *obj, size_t size);
void drm_gem_private_object_init(struct drm_device *dev,
struct drm_gem_object *obj, size_t size);
void drm_gem_private_object_fini(struct drm_gem_object *obj);
void drm_gem_vm_open(struct vm_area_struct *vma);
void drm_gem_vm_close(struct vm_area_struct *vma);
int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
struct vm_area_struct *vma);
int drm_gem_mmap(struct file *filp, struct vm_area_struct *vma);
/**
* drm_gem_object_get - acquire a GEM buffer object reference
* @obj: GEM buffer object
*
* This function acquires an additional reference to @obj. It is illegal to
* call this without already holding a reference. No locks required.
*/
static inline void drm_gem_object_get(struct drm_gem_object *obj)
{
kref_get(&obj->refcount);
}
__attribute__((nonnull))
static inline void
__drm_gem_object_put(struct drm_gem_object *obj)
{
kref_put(&obj->refcount, drm_gem_object_free);
}
/**
* drm_gem_object_put - drop a GEM buffer object reference
* @obj: GEM buffer object
*
* This releases a reference to @obj.
*/
static inline void
drm_gem_object_put(struct drm_gem_object *obj)
{
if (obj)
__drm_gem_object_put(obj);
}
int drm_gem_handle_create(struct drm_file *file_priv,
struct drm_gem_object *obj,
u32 *handlep);
int drm_gem_handle_delete(struct drm_file *filp, u32 handle);
void drm_gem_free_mmap_offset(struct drm_gem_object *obj);
int drm_gem_create_mmap_offset(struct drm_gem_object *obj);
int drm_gem_create_mmap_offset_size(struct drm_gem_object *obj, size_t size);
struct page **drm_gem_get_pages(struct drm_gem_object *obj);
void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
bool dirty, bool accessed);
void drm_gem_lock(struct drm_gem_object *obj);
void drm_gem_unlock(struct drm_gem_object *obj);
int drm_gem_vmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map);
void drm_gem_vunmap_unlocked(struct drm_gem_object *obj, struct iosys_map *map);
int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,
int count, struct drm_gem_object ***objs_out);
struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);
long drm_gem_dma_resv_wait(struct drm_file *filep, u32 handle,
bool wait_all, unsigned long timeout);
int drm_gem_lock_reservations(struct drm_gem_object **objs, int count,
struct ww_acquire_ctx *acquire_ctx);
void drm_gem_unlock_reservations(struct drm_gem_object **objs, int count,
struct ww_acquire_ctx *acquire_ctx);
int drm_gem_dumb_map_offset(struct drm_file *file, struct drm_device *dev,
u32 handle, u64 *offset);
void drm_gem_lru_init(struct drm_gem_lru *lru, struct mutex *lock);
void drm_gem_lru_remove(struct drm_gem_object *obj);
void drm_gem_lru_move_tail_locked(struct drm_gem_lru *lru, struct drm_gem_object *obj);
void drm_gem_lru_move_tail(struct drm_gem_lru *lru, struct drm_gem_object *obj);
unsigned long drm_gem_lru_scan(struct drm_gem_lru *lru,
unsigned int nr_to_scan,
unsigned long *remaining,
bool (*shrink)(struct drm_gem_object *obj));
int drm_gem_evict(struct drm_gem_object *obj);
/**
* drm_gem_object_is_shared_for_memory_stats - helper for shared memory stats
*
* This helper should only be used for fdinfo shared memory stats to determine
* if a GEM object is shared.
*
* @obj: obj in question
*/
static inline bool drm_gem_object_is_shared_for_memory_stats(struct drm_gem_object *obj)
{
return (obj->handle_count > 1) || obj->dma_buf;
}
#ifdef CONFIG_LOCKDEP
/**
* drm_gem_gpuva_set_lock() - Set the lock protecting accesses to the gpuva list.
* @obj: the &drm_gem_object
* @lock: the lock used to protect the gpuva list. The locking primitive
* must contain a dep_map field.
*
* Call this if you're not proctecting access to the gpuva list with the
* dma-resv lock, but with a custom lock.
*/
#define drm_gem_gpuva_set_lock(obj, lock) \
if (!WARN((obj)->gpuva.lock_dep_map, \
"GEM GPUVA lock should be set only once.")) \
(obj)->gpuva.lock_dep_map = &(lock)->dep_map
#define drm_gem_gpuva_assert_lock_held(obj) \
lockdep_assert((obj)->gpuva.lock_dep_map ? \
lock_is_held((obj)->gpuva.lock_dep_map) : \
dma_resv_held((obj)->resv))
#else
#define drm_gem_gpuva_set_lock(obj, lock) do {} while (0)
#define drm_gem_gpuva_assert_lock_held(obj) do {} while (0)
#endif
/**
* drm_gem_gpuva_init() - initialize the gpuva list of a GEM object
* @obj: the &drm_gem_object
*
* This initializes the &drm_gem_object's &drm_gpuvm_bo list.
*
* Calling this function is only necessary for drivers intending to support the
* &drm_driver_feature DRIVER_GEM_GPUVA.
*
* See also drm_gem_gpuva_set_lock().
*/
static inline void drm_gem_gpuva_init(struct drm_gem_object *obj)
{
INIT_LIST_HEAD(&obj->gpuva.list);
}
/**
* drm_gem_for_each_gpuvm_bo() - iterator to walk over a list of &drm_gpuvm_bo
* @entry__: &drm_gpuvm_bo structure to assign to in each iteration step
* @obj__: the &drm_gem_object the &drm_gpuvm_bo to walk are associated with
*
* This iterator walks over all &drm_gpuvm_bo structures associated with the
* &drm_gem_object.
*/
#define drm_gem_for_each_gpuvm_bo(entry__, obj__) \
list_for_each_entry(entry__, &(obj__)->gpuva.list, list.entry.gem)
/**
* drm_gem_for_each_gpuvm_bo_safe() - iterator to safely walk over a list of
* &drm_gpuvm_bo
* @entry__: &drm_gpuvm_bostructure to assign to in each iteration step
* @next__: &next &drm_gpuvm_bo to store the next step
* @obj__: the &drm_gem_object the &drm_gpuvm_bo to walk are associated with
*
* This iterator walks over all &drm_gpuvm_bo structures associated with the
* &drm_gem_object. It is implemented with list_for_each_entry_safe(), hence
* it is save against removal of elements.
*/
#define drm_gem_for_each_gpuvm_bo_safe(entry__, next__, obj__) \
list_for_each_entry_safe(entry__, next__, &(obj__)->gpuva.list, list.entry.gem)
#endif /* __DRM_GEM_H__ */