Re: [Intel-gfx] [RFC PATCH v3 13/17] drm/i915/vm_bind: userptr dma-resv changes

Niranjana Vishwanathapura
2022-08-31T06:45:55Z

On Sat, Aug 27, 2022 at 09:43:59PM +0200, Andi Shyti wrote:
>From: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
>
>For persistent (vm_bind) vmas of userptr BOs, handle the user
>page pinning by using the i915_gem_object_userptr_submit_init()
>/done() functions
>
>Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
>Signed-off-by: Ramalingam C <ramalingam.c@intel.com>
>Signed-off-by: Andi Shyti <andi.shyti@linux.intel.com>
>---
> .../gpu/drm/i915/gem/i915_gem_execbuffer3.c | 139 ++++++++++++++----
> drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 10 ++
> .../drm/i915/gem/i915_gem_vm_bind_object.c | 16 ++
> drivers/gpu/drm/i915/gt/intel_gtt.c | 2 +
> drivers/gpu/drm/i915/gt/intel_gtt.h | 4 +
> drivers/gpu/drm/i915/i915_vma_types.h | 2 +
> 6 files changed, 142 insertions(+), 31 deletions(-)
>
>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c
>index 8e0dde26194e0..72d6771da2113 100644
>--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c
>+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c
>@@ -23,6 +23,7 @@
> #include "i915_gem_vm_bind.h"
> #include "i915_trace.h"
>
>+#define __EXEC3_USERPTR_USED BIT_ULL(34)
> #define __EXEC3_HAS_PIN BIT_ULL(33)
> #define __EXEC3_ENGINE_PINNED BIT_ULL(32)
> #define __EXEC3_INTERNAL_FLAGS (~0ull << 32)
>@@ -157,10 +158,45 @@ static void eb_scoop_unbound_vma_all(struct i915_address_space *vm)
> spin_unlock(&vm->vm_rebind_lock);
> }
>
>+static int eb_lookup_persistent_userptr_vmas(struct i915_execbuffer *eb)
>+{
>+ struct i915_address_space *vm = eb->context->vm;
>+ struct i915_vma *last_vma = NULL;
>+ struct i915_vma *vma;
>+ int err;
>+
>+ lockdep_assert_held(&vm->vm_bind_lock);
>+
>+ list_for_each_entry(vma, &vm->vm_userptr_invalidated_list,
>+ vm_userptr_invalidated_link) {
>+ list_del_init(&vma->vm_userptr_invalidated_link);
>+ err = i915_gem_object_userptr_submit_init(vma->obj);
>+ if (err)
>+ return err;
>+
>+ last_vma = vma;
>+ }

This should be done under the list lock. As it is a spinlock, we
should scoop them first under that spinlock and call submit_init()
outside that lock.

>+
>+ list_for_each_entry(vma, &vm->vm_bind_list, vm_bind_link)
>+ if (i915_gem_object_is_userptr(vma->obj)) {
>+ err = i915_gem_object_userptr_submit_init(vma->obj);
>+ if (err)
>+ return err;
>+
>+ last_vma = vma;
>+ }
>+
>+ if (last_vma)
>+ eb->args->flags |= __EXEC3_USERPTR_USED;
>+
>+ return 0;
>+}
>+
> static int eb_lookup_vma_all(struct i915_execbuffer *eb)
> {
> unsigned int i, current_batch = 0;
> struct i915_vma *vma;
>+ int err = 0;
>
> for (i = 0; i < eb->num_batches; i++) {
> vma = eb_find_vma(eb->context->vm, eb->batch_addresses[i]);
>@@ -171,6 +207,10 @@ static int eb_lookup_vma_all(struct i915_execbuffer *eb)
> ++current_batch;
> }
>
>+ err = eb_lookup_persistent_userptr_vmas(eb);
>+ if (err)
>+ return err;
>+
> eb_scoop_unbound_vma_all(eb->context->vm);
>
> return 0;
>@@ -286,33 +326,6 @@ static int eb_validate_persistent_vma_all(struct i915_execbuffer *eb)
> return ret;
> }
>
>-static int eb_validate_vma_all(struct i915_execbuffer *eb)
>-{
>- /* only throttle once, even if we didn't need to throttle */
>- for (bool throttle = true;; throttle = false) {
>- int err;
>-
>- err = eb_pin_engine(eb, throttle);
>- if (!err)
>- err = eb_lock_vma_all(eb);
>-
>- if (!err)
>- err = eb_validate_persistent_vma_all(eb);
>-
>- if (!err)
>- return 0;
>-
>- if (err != -EDEADLK)
>- return err;
>-
>- err = i915_gem_ww_ctx_backoff(&eb->ww);
>- if (err)
>- return err;
>- }
>-
>- return 0;
>-}
>-
> /*
> * Using two helper loops for the order of which requests / batches are created
> * and added the to backend. Requests are created in order from the parent to
>@@ -360,15 +373,51 @@ static void eb_move_all_persistent_vma_to_active(struct i915_execbuffer *eb)
>
> static int eb_move_to_gpu(struct i915_execbuffer *eb)
> {
>+ int err = 0, j;
>+
> lockdep_assert_held(&eb->context->vm->vm_bind_lock);
> assert_object_held(eb->context->vm->root_obj);
>
> eb_move_all_persistent_vma_to_active(eb);
>
>- /* Unconditionally flush any chipset caches (for streaming writes). */
>- intel_gt_chipset_flush(eb->gt);
>+#ifdef CONFIG_MMU_NOTIFIER
>+ if (!err && (eb->args->flags & __EXEC3_USERPTR_USED)) {
>+ struct i915_vma *vma;
>
>- return 0;
>+ lockdep_assert_held(&eb->context->vm->vm_bind_lock);
>+ assert_object_held(eb->context->vm->root_obj);
>+
>+ read_lock(&eb->i915->mm.notifier_lock);
>+ list_for_each_entry(vma, &eb->context->vm->vm_bind_list,
>+ vm_bind_link) {
>+ if (!i915_gem_object_is_userptr(vma->obj))
>+ continue;
>+
>+ err = i915_gem_object_userptr_submit_done(vma->obj);
>+ if (err)
>+ break;
>+ }
>+
>+ read_unlock(&eb->i915->mm.notifier_lock);
>+ }
>+#endif
>+
>+ if (likely(!err)) {
>+ /*
>+ * Unconditionally flush any
>+ * chipset caches (for streaming writes).
>+ */
>+ intel_gt_chipset_flush(eb->gt);
>+ return 0;
>+ }
>+
>+ for_each_batch_create_order(eb, j) {
>+ if (!eb->requests[j])
>+ break;
>+
>+ i915_request_set_error_once(eb->requests[j], err);
>+ }
>+ return err;
> }
>
> static int eb_request_submit(struct i915_execbuffer *eb,
>@@ -1088,6 +1137,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
> {
> struct drm_i915_private *i915 = to_i915(dev);
> struct i915_execbuffer eb;
>+ bool throttle = true;
> int err;
>
> BUILD_BUG_ON(__EXEC3_INTERNAL_FLAGS & ~__I915_EXEC3_UNKNOWN_FLAGS);
>@@ -1121,6 +1171,7 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>
> mutex_lock(&eb.context->vm->vm_bind_lock);
>
>+lookup_vmas:
> err = eb_lookup_vma_all(&eb);
> if (err) {
> eb_release_vma_all(&eb, true);
>@@ -1129,7 +1180,33 @@ i915_gem_do_execbuffer(struct drm_device *dev,
>
> i915_gem_ww_ctx_init(&eb.ww, true);
>
>- err = eb_validate_vma_all(&eb);
>+retry_validate:
>+ err = eb_pin_engine(&eb, throttle);
>+ if (err)
>+ goto err_validate;
>+
>+ /* only throttle once, even if we didn't need to throttle */
>+ throttle = false;
>+
>+ err = eb_lock_vma_all(&eb);
>+ if (err)
>+ goto err_validate;
>+
>+ if (!list_empty(&eb.context->vm->vm_rebind_list)) {
>+ eb_release_vma_all(&eb, true);
>+ i915_gem_ww_ctx_fini(&eb.ww);
>+ goto lookup_vmas;
>+ }
>+
>+ err = eb_validate_persistent_vma_all(&eb);
>+
>+err_validate:
>+ if (err == -EDEADLK) {
>+ eb_release_vma_all(&eb, false);
>+ err = i915_gem_ww_ctx_backoff(&eb.ww);
>+ if (!err)
>+ goto retry_validate;
>+ }
> if (err)
> goto err_vma;
>
>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
>index 8423df021b713..f980d7443fa27 100644
>--- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
>+++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
>@@ -63,6 +63,7 @@ static bool i915_gem_userptr_invalidate(struct mmu_interval_notifier *mni,
> {
> struct drm_i915_gem_object *obj = container_of(mni, struct drm_i915_gem_object, userptr.notifier);
> struct drm_i915_private *i915 = to_i915(obj->base.dev);
>+ struct i915_vma *vma;
> long r;
>
> if (!mmu_notifier_range_blockable(range))
>@@ -85,6 +86,15 @@ static bool i915_gem_userptr_invalidate(struct mmu_interval_notifier *mni,
> if (current->flags & PF_EXITING)
> return true;
>
>+ spin_lock(&obj->vma.lock);
>+ list_for_each_entry(vma, &obj->vma.list, obj_link) {
>+ spin_lock(&vma->vm->vm_userptr_invalidated_lock);
>+ list_add_tail(&vma->vm_userptr_invalidated_link,
>+ &vma->vm->vm_userptr_invalidated_list);
>+ spin_unlock(&vma->vm->vm_userptr_invalidated_lock);

Should be done only if vma is persistent.

Niranjana

>+ }
>+ spin_unlock(&obj->vma.lock);
>+
> /* we will unbind on next submission, still have userptr pins */
> r = dma_resv_wait_timeout(obj->base.resv, DMA_RESV_USAGE_BOOKKEEP, false,
> MAX_SCHEDULE_TIMEOUT);
>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>index e57b9c492a7f9..e6216f49e7d58 100644
>--- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>+++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
>@@ -296,6 +296,12 @@ static int i915_gem_vm_bind_obj(struct i915_address_space *vm,
> goto put_obj;
> }
>
>+ if (i915_gem_object_is_userptr(obj)) {
>+ ret = i915_gem_object_userptr_submit_init(obj);
>+ if (ret)
>+ goto put_obj;
>+ }
>+
> ret = mutex_lock_interruptible(&vm->vm_bind_lock);
> if (ret)
> goto put_obj;
>@@ -328,6 +334,16 @@ static int i915_gem_vm_bind_obj(struct i915_address_space *vm,
> /* Make it evictable */
> __i915_vma_unpin(vma);
>
>+#ifdef CONFIG_MMU_NOTIFIER
>+ if (i915_gem_object_is_userptr(obj)) {
>+ read_lock(&vm->i915->mm.notifier_lock);
>+ ret = i915_gem_object_userptr_submit_done(obj);
>+ read_unlock(&vm->i915->mm.notifier_lock);
>+ if (ret)
>+ goto out_ww;
>+ }
>+#endif
>+
> list_add_tail(&vma->vm_bind_link, &vm->vm_bound_list);
> i915_vm_bind_it_insert(vma, &vm->va);
> if (!obj->priv_root)
>diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
>index 97cd0089b516d..f1db8310de4a6 100644
>--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
>+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
>@@ -298,6 +298,8 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
> GEM_BUG_ON(IS_ERR(vm->root_obj));
> INIT_LIST_HEAD(&vm->vm_rebind_list);
> spin_lock_init(&vm->vm_rebind_lock);
>+ spin_lock_init(&vm->vm_userptr_invalidated_lock);
>+ INIT_LIST_HEAD(&vm->vm_userptr_invalidated_list);
> }
>
> void *__px_vaddr(struct drm_i915_gem_object *p)
>diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.h b/drivers/gpu/drm/i915/gt/intel_gtt.h
>index 1f3b1967ec175..71203d65e1d60 100644
>--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
>+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
>@@ -269,6 +269,10 @@ struct i915_address_space {
> struct list_head vm_rebind_list;
> /* @vm_rebind_lock: protects vm_rebound_list */
> spinlock_t vm_rebind_lock;
>+ /* @vm_userptr_invalidated_list: list of invalidated userptr vmas */
>+ struct list_head vm_userptr_invalidated_list;
>+ /* @vm_userptr_invalidated_lock: protects vm_userptr_invalidated_list */
>+ spinlock_t vm_userptr_invalidated_lock;
> /* @va: tree of persistent vmas */
> struct rb_root_cached va;
> struct list_head non_priv_vm_bind_list;
>diff --git a/drivers/gpu/drm/i915/i915_vma_types.h b/drivers/gpu/drm/i915/i915_vma_types.h
>index 8bf870a0f689b..5b583ca744387 100644
>--- a/drivers/gpu/drm/i915/i915_vma_types.h
>+++ b/drivers/gpu/drm/i915/i915_vma_types.h
>@@ -317,6 +317,8 @@ struct i915_vma {
> struct list_head non_priv_vm_bind_link;
> /* @vm_rebind_link: link to vm_rebind_list and protected by vm_rebind_lock */
> struct list_head vm_rebind_link; /* Link in vm_rebind_list */
>+ /*@vm_userptr_invalidated_link: link to the vm->vm_userptr_invalidated_list */
>+ struct list_head vm_userptr_invalidated_link;
>
> /** Timeline fence for vm_bind completion notification */
> struct {
>--
>2.34.1
>