Commit a3258dbd authored by Thomas Hellström's avatar Thomas Hellström Committed by Daniel Vetter
Browse files

drm/i915: Prepare for obj->mm.lock removal, v2. 



Stolen objects need to lock, and we may call put_pages when
refcount drops to 0, ensure all calls are handled correctly.

Changes since v1:
- Rebase on top of upstream changes.

Idea-from: Thomas Hellström <thomas.hellstrom@intel.com>
Signed-off-by: default avatarThomas Hellström <thomas.hellstrom@linux.intel.com>
Signed-off-by: default avatarMaarten Lankhorst <maarten.lankhorst@linux.intel.com>
Reviewed-by: default avatarMatthew Auld <matthew.auld@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
Link: https://patchwork.freedesktop.org/patch/msgid/20210323155059.628690-33-maarten.lankhorst@linux.intel.com
parent 74827b53

drivers/gpu/drm/i915/gem/i915_gem_object.h

+14 −0
Original line number Diff line number Diff line
@@ -118,6 +118,20 @@ i915_gem_object_put(struct drm_i915_gem_object *obj) 


#define assert_object_held(obj) dma_resv_assert_held((obj)->base.resv)



/*

 * If more than one potential simultaneous locker, assert held.

 */

static inline void assert_object_held_shared(struct drm_i915_gem_object *obj)

{

	/*

	 * Note mm list lookup is protected by

	 * kref_get_unless_zero().

	 */

	if (IS_ENABLED(CONFIG_LOCKDEP) &&

	    kref_read(&obj->base.refcount) > 0)

		lockdep_assert_held(&obj->mm.lock);

}



static inline int __i915_gem_object_lock(struct drm_i915_gem_object *obj,

					 struct i915_gem_ww_ctx *ww,

					 bool intr)

drivers/gpu/drm/i915/gem/i915_gem_pages.c

+12 −2
Original line number Diff line number Diff line
@@ -19,7 +19,7 @@ void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj, 
	bool shrinkable;

	int i;



	lockdep_assert_held(&obj->mm.lock);

	assert_object_held_shared(obj);



	if (i915_gem_object_is_volatile(obj))

		obj->mm.madv = I915_MADV_DONTNEED;
@@ -70,6 +70,7 @@ void __i915_gem_object_set_pages(struct drm_i915_gem_object *obj, 
		struct list_head *list;

		unsigned long flags;



		lockdep_assert_held(&obj->mm.lock);

		spin_lock_irqsave(&i915->mm.obj_lock, flags);



		i915->mm.shrink_count++;
@@ -91,6 +92,8 @@ int ____i915_gem_object_get_pages(struct drm_i915_gem_object *obj) 
	struct drm_i915_private *i915 = to_i915(obj->base.dev);

	int err;



	assert_object_held_shared(obj);



	if (unlikely(obj->mm.madv != I915_MADV_WILLNEED)) {

		drm_dbg(&i915->drm,

			"Attempting to obtain a purgeable object\n");
@@ -118,6 +121,8 @@ int __i915_gem_object_get_pages(struct drm_i915_gem_object *obj) 
	if (err)

		return err;



	assert_object_held_shared(obj);



	if (unlikely(!i915_gem_object_has_pages(obj))) {

		GEM_BUG_ON(i915_gem_object_has_pinned_pages(obj));
@@ -145,7 +150,7 @@ void i915_gem_object_truncate(struct drm_i915_gem_object *obj) 
/* Try to discard unwanted pages */

void i915_gem_object_writeback(struct drm_i915_gem_object *obj)

{

	lockdep_assert_held(&obj->mm.lock);

	assert_object_held_shared(obj);

	GEM_BUG_ON(i915_gem_object_has_pages(obj));



	if (obj->ops->writeback)
@@ -176,6 +181,8 @@ __i915_gem_object_unset_pages(struct drm_i915_gem_object *obj) 
{

	struct sg_table *pages;



	assert_object_held_shared(obj);



	pages = fetch_and_zero(&obj->mm.pages);

	if (IS_ERR_OR_NULL(pages))

		return pages;
@@ -203,6 +210,9 @@ int __i915_gem_object_put_pages_locked(struct drm_i915_gem_object *obj) 
	if (i915_gem_object_has_pinned_pages(obj))

		return -EBUSY;



	/* May be called by shrinker from within get_pages() (on another bo) */

	assert_object_held_shared(obj);



	i915_gem_object_release_mmap_offset(obj);



	/*

drivers/gpu/drm/i915/gem/i915_gem_stolen.c

+7 −5
Original line number Diff line number Diff line
@@ -637,13 +637,15 @@ static int __i915_gem_object_create_stolen(struct intel_memory_region *mem, 
	cache_level = HAS_LLC(mem->i915) ? I915_CACHE_LLC : I915_CACHE_NONE;

	i915_gem_object_set_cache_coherency(obj, cache_level);



	err = i915_gem_object_pin_pages(obj);

	if (err)

		return err;

	if (WARN_ON(!i915_gem_object_trylock(obj)))

		return -EBUSY;



	err = i915_gem_object_pin_pages(obj);

	if (!err)

		i915_gem_object_init_memory_region(obj, mem);

	i915_gem_object_unlock(obj);



	return 0;

	return err;

}



static int _i915_gem_object_stolen_init(struct intel_memory_region *mem,