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drm/i915/dgfx: Grab wakeref at i915_ttm_unmap_virtual

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We had already grabbed the rpm wakeref at obj destruction path,
but it also required to grab the wakeref when object moves.
When i915_gem_object_release_mmap_offset() gets called by
i915_ttm_move_notify(), it will release the mmap offset without
grabbing the wakeref. We want to avoid that therefore,
grab the wakeref at i915_ttm_unmap_virtual() accordingly.

While doing that also changed the lmem_userfault_lock from
mutex to spinlock, as spinlock widely used for list.

Also changed if (obj->userfault_count) to
GEM_BUG_ON(!obj->userfault_count).

v2:
- Removed lmem_userfault_{list,lock} from intel_gt. [Matt Auld]

Fixes: ad74457a6b5a ("drm/i915/dgfx: Release mmap on rpm suspend")
Suggested-by: Matthew Auld <matthew.auld@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221027092242.1476080-3-anshuman.gupta@intel.com
This commit is contained in:
Anshuman Gupta 2022-10-27 14:52:42 +05:30
parent e66c8dcf99
commit 1cacd6894d
4 changed files with 35 additions and 26 deletions
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19
drivers/gpu/drm/i915/gem/i915_gem_mman.c
View File

@ -557,11 +557,13 @@ void i915_gem_object_runtime_pm_release_mmap_offset(struct drm_i915_gem_object *
drm_vma_node_unmap(&bo->base.vma_node, bdev->dev_mapping);
if (obj->userfault_count) {
/* rpm wakeref provide exclusive access */
list_del(&obj->userfault_link);
obj->userfault_count = 0;
}
/*
* We have exclusive access here via runtime suspend. All other callers
* must first grab the rpm wakeref.
*/
GEM_BUG_ON(!obj->userfault_count);
list_del(&obj->userfault_link);
obj->userfault_count = 0;
}
void i915_gem_object_release_mmap_offset(struct drm_i915_gem_object *obj)
@ -587,13 +589,6 @@ void i915_gem_object_release_mmap_offset(struct drm_i915_gem_object *obj)
spin_lock(&obj->mmo.lock);
}
spin_unlock(&obj->mmo.lock);
if (obj->userfault_count) {
mutex_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
list_del(&obj->userfault_link);
mutex_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
obj->userfault_count = 0;
}
}
static struct i915_mmap_offset *

38
drivers/gpu/drm/i915/gem/i915_gem_ttm.c
View File

@ -509,18 +509,9 @@ static int i915_ttm_shrink(struct drm_i915_gem_object *obj, unsigned int flags)
static void i915_ttm_delete_mem_notify(struct ttm_buffer_object *bo)
{
struct drm_i915_gem_object *obj = i915_ttm_to_gem(bo);
intel_wakeref_t wakeref = 0;
if (bo->resource && !i915_ttm_is_ghost_object(bo)) {
/* ttm_bo_release() already has dma_resv_lock */
if (i915_ttm_cpu_maps_iomem(bo->resource))
wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm);
__i915_gem_object_pages_fini(obj);
if (wakeref)
intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref);
i915_ttm_free_cached_io_rsgt(obj);
}
}
@ -1098,12 +1089,15 @@ static vm_fault_t vm_fault_ttm(struct vm_fault *vmf)
if (ret == VM_FAULT_RETRY && !(vmf->flags & FAULT_FLAG_RETRY_NOWAIT))
goto out_rpm;
/* ttm_bo_vm_reserve() already has dma_resv_lock */
/*
* ttm_bo_vm_reserve() already has dma_resv_lock.
* userfault_count is protected by dma_resv lock and rpm wakeref.
*/
if (ret == VM_FAULT_NOPAGE && wakeref && !obj->userfault_count) {
obj->userfault_count = 1;
mutex_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
spin_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
list_add(&obj->userfault_link, &to_i915(obj->base.dev)->runtime_pm.lmem_userfault_list);
mutex_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
spin_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
}
if (wakeref & CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND)
@ -1169,7 +1163,27 @@ static u64 i915_ttm_mmap_offset(struct drm_i915_gem_object *obj)
static void i915_ttm_unmap_virtual(struct drm_i915_gem_object *obj)
{
struct ttm_buffer_object *bo = i915_gem_to_ttm(obj);
intel_wakeref_t wakeref = 0;
assert_object_held_shared(obj);
if (i915_ttm_cpu_maps_iomem(bo->resource)) {
wakeref = intel_runtime_pm_get(&to_i915(obj->base.dev)->runtime_pm);
/* userfault_count is protected by obj lock and rpm wakeref. */
if (obj->userfault_count) {
spin_lock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
list_del(&obj->userfault_link);
spin_unlock(&to_i915(obj->base.dev)->runtime_pm.lmem_userfault_lock);
obj->userfault_count = 0;
}
}
ttm_bo_unmap_virtual(i915_gem_to_ttm(obj));
if (wakeref)
intel_runtime_pm_put(&to_i915(obj->base.dev)->runtime_pm, wakeref);
}
static const struct drm_i915_gem_object_ops i915_gem_ttm_obj_ops = {

2
drivers/gpu/drm/i915/intel_runtime_pm.c
View File

@ -648,6 +648,6 @@ void intel_runtime_pm_init_early(struct intel_runtime_pm *rpm)
init_intel_runtime_pm_wakeref(rpm);
INIT_LIST_HEAD(&rpm->lmem_userfault_list);
mutex_init(&rpm->lmem_userfault_lock);
spin_lock_init(&rpm->lmem_userfault_lock);
intel_wakeref_auto_init(&rpm->userfault_wakeref, rpm);
}

2
drivers/gpu/drm/i915/intel_runtime_pm.h
View File

@ -64,7 +64,7 @@ struct intel_runtime_pm {
* but instead has exclusive access by virtue of all other accesses requiring
* holding the runtime pm wakeref.
*/
struct mutex lmem_userfault_lock;
spinlock_t lmem_userfault_lock;
/*
* Keep list of userfaulted gem obj, which require to release their