diff options
Diffstat (limited to 'drivers/gpu/drm/drm_gpuvm.c')
| -rw-r--r-- | drivers/gpu/drm/drm_gpuvm.c | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_gpuvm.c b/drivers/gpu/drm/drm_gpuvm.c index af63f4d00315..8a06d296561d 100644 --- a/drivers/gpu/drm/drm_gpuvm.c +++ b/drivers/gpu/drm/drm_gpuvm.c @@ -26,6 +26,7 @@ */ #include <drm/drm_gpuvm.h> +#include <drm/drm_print.h> #include <linux/export.h> #include <linux/interval_tree_generic.h> @@ -877,6 +878,31 @@ __drm_gpuvm_bo_list_add(struct drm_gpuvm *gpuvm, spinlock_t *lock, } /** + * drm_gpuvm_bo_is_zombie() - check whether this vm_bo is scheduled for cleanup + * @vm_bo: the &drm_gpuvm_bo + * + * When a vm_bo is scheduled for cleanup using the bo_defer list, it is not + * immediately removed from the evict and extobj lists. Therefore, anyone + * iterating these lists should skip entries that are being destroyed. + * + * Checking the refcount without incrementing it is okay as long as the lock + * protecting the evict/extobj list is held for as long as you are using the + * vm_bo, because even if the refcount hits zero while you are using it, freeing + * the vm_bo requires taking the list's lock. + * + * Zombie entries can be observed on the evict and extobj lists regardless of + * whether DRM_GPUVM_RESV_PROTECTED is used, but they remain on the lists for a + * longer time when the resv lock is used because we can't take the resv lock + * during run_job() in immediate mode, meaning that they need to remain on the + * lists until drm_gpuvm_bo_deferred_cleanup() is called. + */ +static bool +drm_gpuvm_bo_is_zombie(struct drm_gpuvm_bo *vm_bo) +{ + return !kref_read(&vm_bo->kref); +} + +/** * drm_gpuvm_bo_list_add() - insert a vm_bo into the given list * @__vm_bo: the &drm_gpuvm_bo * @__list_name: the name of the list to insert into @@ -1081,6 +1107,8 @@ drm_gpuvm_init(struct drm_gpuvm *gpuvm, const char *name, INIT_LIST_HEAD(&gpuvm->evict.list); spin_lock_init(&gpuvm->evict.lock); + init_llist_head(&gpuvm->bo_defer); + kref_init(&gpuvm->kref); gpuvm->name = name ? name : "unknown"; @@ -1122,6 +1150,8 @@ drm_gpuvm_fini(struct drm_gpuvm *gpuvm) "Extobj list should be empty.\n"); drm_WARN(gpuvm->drm, !list_empty(&gpuvm->evict.list), "Evict list should be empty.\n"); + drm_WARN(gpuvm->drm, !llist_empty(&gpuvm->bo_defer), + "VM BO cleanup list should be empty.\n"); drm_gem_object_put(gpuvm->r_obj); } @@ -1217,6 +1247,9 @@ drm_gpuvm_prepare_objects_locked(struct drm_gpuvm *gpuvm, drm_gpuvm_resv_assert_held(gpuvm); list_for_each_entry(vm_bo, &gpuvm->extobj.list, list.entry.extobj) { + if (drm_gpuvm_bo_is_zombie(vm_bo)) + continue; + ret = exec_prepare_obj(exec, vm_bo->obj, num_fences); if (ret) break; @@ -1460,6 +1493,9 @@ drm_gpuvm_validate_locked(struct drm_gpuvm *gpuvm, struct drm_exec *exec) list_for_each_entry_safe(vm_bo, next, &gpuvm->evict.list, list.entry.evict) { + if (drm_gpuvm_bo_is_zombie(vm_bo)) + continue; + ret = ops->vm_bo_validate(vm_bo, exec); if (ret) break; @@ -1560,6 +1596,7 @@ drm_gpuvm_bo_create(struct drm_gpuvm *gpuvm, INIT_LIST_HEAD(&vm_bo->list.entry.extobj); INIT_LIST_HEAD(&vm_bo->list.entry.evict); + init_llist_node(&vm_bo->list.entry.bo_defer); return vm_bo; } @@ -1621,6 +1658,126 @@ drm_gpuvm_bo_put(struct drm_gpuvm_bo *vm_bo) } EXPORT_SYMBOL_GPL(drm_gpuvm_bo_put); +/* + * drm_gpuvm_bo_into_zombie() - called when the vm_bo becomes a zombie due to + * deferred cleanup + * + * If deferred cleanup is used, then this must be called right after the vm_bo + * refcount drops to zero. Must be called with GEM mutex held. After releasing + * the GEM mutex, drm_gpuvm_bo_defer_zombie_cleanup() must be called. + */ +static void +drm_gpuvm_bo_into_zombie(struct kref *kref) +{ + struct drm_gpuvm_bo *vm_bo = container_of(kref, struct drm_gpuvm_bo, + kref); + + if (!drm_gpuvm_resv_protected(vm_bo->vm)) { + drm_gpuvm_bo_list_del(vm_bo, extobj, true); + drm_gpuvm_bo_list_del(vm_bo, evict, true); + } + + list_del(&vm_bo->list.entry.gem); +} + +/* + * drm_gpuvm_bo_defer_zombie_cleanup() - adds a new zombie vm_bo to the + * bo_defer list + * + * Called after drm_gpuvm_bo_into_zombie(). GEM mutex must not be held. + * + * It's important that the GEM stays alive for the duration in which we hold + * the mutex, but the instant we add the vm_bo to bo_defer, another thread + * might call drm_gpuvm_bo_deferred_cleanup() and put the GEM. Therefore, to + * avoid kfreeing a mutex we are holding, the GEM mutex must be released + * *before* calling this function. + */ +static void +drm_gpuvm_bo_defer_zombie_cleanup(struct drm_gpuvm_bo *vm_bo) +{ + llist_add(&vm_bo->list.entry.bo_defer, &vm_bo->vm->bo_defer); +} + +static void +drm_gpuvm_bo_defer_free(struct kref *kref) +{ + struct drm_gpuvm_bo *vm_bo = container_of(kref, struct drm_gpuvm_bo, + kref); + + drm_gpuvm_bo_into_zombie(kref); + mutex_unlock(&vm_bo->obj->gpuva.lock); + drm_gpuvm_bo_defer_zombie_cleanup(vm_bo); +} + +/** + * drm_gpuvm_bo_put_deferred() - drop a struct drm_gpuvm_bo reference with + * deferred cleanup + * @vm_bo: the &drm_gpuvm_bo to release the reference of + * + * This releases a reference to @vm_bo. + * + * This might take and release the GEMs GPUVA lock. You should call + * drm_gpuvm_bo_deferred_cleanup() later to complete the cleanup process. + * + * Returns: true if vm_bo is being destroyed, false otherwise. + */ +bool +drm_gpuvm_bo_put_deferred(struct drm_gpuvm_bo *vm_bo) +{ + if (!vm_bo) + return false; + + drm_WARN_ON(vm_bo->vm->drm, !drm_gpuvm_immediate_mode(vm_bo->vm)); + + return !!kref_put_mutex(&vm_bo->kref, + drm_gpuvm_bo_defer_free, + &vm_bo->obj->gpuva.lock); +} +EXPORT_SYMBOL_GPL(drm_gpuvm_bo_put_deferred); + +/** + * drm_gpuvm_bo_deferred_cleanup() - clean up BOs in the deferred list + * deferred cleanup + * @gpuvm: the VM to clean up + * + * Cleans up &drm_gpuvm_bo instances in the deferred cleanup list. + */ +void +drm_gpuvm_bo_deferred_cleanup(struct drm_gpuvm *gpuvm) +{ + const struct drm_gpuvm_ops *ops = gpuvm->ops; + struct drm_gpuvm_bo *vm_bo; + struct drm_gem_object *obj; + struct llist_node *bo_defer; + + bo_defer = llist_del_all(&gpuvm->bo_defer); + if (!bo_defer) + return; + + if (drm_gpuvm_resv_protected(gpuvm)) { + dma_resv_lock(drm_gpuvm_resv(gpuvm), NULL); + llist_for_each_entry(vm_bo, bo_defer, list.entry.bo_defer) { + drm_gpuvm_bo_list_del(vm_bo, extobj, false); + drm_gpuvm_bo_list_del(vm_bo, evict, false); + } + dma_resv_unlock(drm_gpuvm_resv(gpuvm)); + } + + while (bo_defer) { + vm_bo = llist_entry(bo_defer, struct drm_gpuvm_bo, list.entry.bo_defer); + bo_defer = bo_defer->next; + obj = vm_bo->obj; + if (ops && ops->vm_bo_free) + ops->vm_bo_free(vm_bo); + else + kfree(vm_bo); + + drm_gpuvm_put(gpuvm); + drm_gem_object_put(obj); + } +} +EXPORT_SYMBOL_GPL(drm_gpuvm_bo_deferred_cleanup); + static struct drm_gpuvm_bo * __drm_gpuvm_bo_find(struct drm_gpuvm *gpuvm, struct drm_gem_object *obj) @@ -1949,6 +2106,40 @@ drm_gpuva_unlink(struct drm_gpuva *va) EXPORT_SYMBOL_GPL(drm_gpuva_unlink); /** + * drm_gpuva_unlink_defer() - unlink a &drm_gpuva with deferred vm_bo cleanup + * @va: the &drm_gpuva to unlink + * + * Similar to drm_gpuva_unlink(), but uses drm_gpuvm_bo_put_deferred() and takes + * the lock for the caller. + */ +void +drm_gpuva_unlink_defer(struct drm_gpuva *va) +{ + struct drm_gem_object *obj = va->gem.obj; + struct drm_gpuvm_bo *vm_bo = va->vm_bo; + bool should_defer_bo; + + if (unlikely(!obj)) + return; + + drm_WARN_ON(vm_bo->vm->drm, !drm_gpuvm_immediate_mode(vm_bo->vm)); + + mutex_lock(&obj->gpuva.lock); + list_del_init(&va->gem.entry); + + /* + * This is drm_gpuvm_bo_put_deferred() except we already hold the mutex. + */ + should_defer_bo = kref_put(&vm_bo->kref, drm_gpuvm_bo_into_zombie); + mutex_unlock(&obj->gpuva.lock); + if (should_defer_bo) + drm_gpuvm_bo_defer_zombie_cleanup(vm_bo); + + va->vm_bo = NULL; +} +EXPORT_SYMBOL_GPL(drm_gpuva_unlink_defer); + +/** * drm_gpuva_find_first() - find the first &drm_gpuva in the given range * @gpuvm: the &drm_gpuvm to search in * @addr: the &drm_gpuvas address |