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 wakreref 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).
Fixes: ad74457a6b5a ("drm/i915/dgfx: Release mmap on rpm suspend")
Suggested-by: Matthew Auld <matthew.auld@xxxxxxxxx>
Signed-off-by: Anshuman Gupta <anshuman.gupta@xxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_mman.c | 19 +++++-------
drivers/gpu/drm/i915/gem/i915_gem_ttm.c | 39 ++++++++++++++++--------
drivers/gpu/drm/i915/gt/intel_gt.c | 11 ++++++-
drivers/gpu/drm/i915/gt/intel_gt_types.h | 2 +-
4 files changed, 45 insertions(+), 26 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index 73d9eda1d6b7..9da561c19a47 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -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_gt(to_i915(obj->base.dev))->lmem_userfault_lock);
- list_del(&obj->userfault_link);
- mutex_unlock(&to_gt(to_i915(obj->base.dev))->lmem_userfault_lock);
- obj->userfault_count = 0;
- }
}
static struct i915_mmap_offset *
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
index e3fc38dd5db0..0630eeca7316 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_ttm.c
@@ -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 && likely(obj)) {
- /* 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);
}
}
@@ -1052,12 +1043,15 @@ 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_gt(to_i915(obj->base.dev))->lmem_userfault_lock);
+ spin_lock(to_gt(to_i915(obj->base.dev))->lmem_userfault_lock);
list_add(&obj->userfault_link, &to_gt(to_i915(obj->base.dev))->lmem_userfault_list);
- mutex_unlock(&to_gt(to_i915(obj->base.dev))->lmem_userfault_lock);
+ spin_unlock(to_gt(to_i915(obj->base.dev))->lmem_userfault_lock);
}
if (wakeref & CONFIG_DRM_I915_USERFAULT_AUTOSUSPEND)
@@ -1123,7 +1117,28 @@ 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_gt(to_i915(obj->base.dev))->lmem_userfault_lock);
+ list_del(&obj->userfault_link);
+ spin_unlock(to_gt(to_i915(obj->base.dev))->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 = {
diff --git a/drivers/gpu/drm/i915/gt/intel_gt.c b/drivers/gpu/drm/i915/gt/intel_gt.c
index b367cfff48d5..1e63432d97bb 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt.c
@@ -41,7 +41,7 @@ void intel_gt_common_init_early(struct intel_gt *gt)
spin_lock_init(gt->irq_lock);
INIT_LIST_HEAD(>->lmem_userfault_list);
- mutex_init(>->lmem_userfault_lock);
+ spin_lock_init(gt->lmem_userfault_lock);
INIT_LIST_HEAD(>->closed_vma);
spin_lock_init(>->closed_lock);
@@ -71,6 +71,10 @@ int intel_root_gt_init_early(struct drm_i915_private *i915)
if (!gt->irq_lock)
return -ENOMEM;
+ gt->lmem_userfault_lock = drmm_kzalloc(&i915->drm, sizeof(*gt->lmem_userfault_lock), GFP_KERNEL);
+ if (!gt->lmem_userfault_lock)
+ return -ENOMEM;
+
intel_gt_common_init_early(gt);
return 0;
@@ -813,6 +817,11 @@ static int intel_gt_tile_setup(struct intel_gt *gt, phys_addr_t phys_addr)
gt->uncore = uncore;
gt->irq_lock = irq_lock;
+ gt->lmem_userfault_lock = drmm_kzalloc(>->i915->drm,
+ sizeof(*gt->lmem_userfault_lock), GFP_KERNEL);
+ if (!gt->lmem_userfault_lock)
+ return -ENOMEM;
+
intel_gt_common_init_early(gt);
}
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_types.h b/drivers/gpu/drm/i915/gt/intel_gt_types.h
index 30003d68fd51..925775310b1e 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_types.h
@@ -153,7 +153,7 @@ struct intel_gt {
* 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;
struct list_head lmem_userfault_list;
struct list_head closed_vma;
--
2.26.2
