On 18/10/2022 08:16, Niranjana Vishwanathapura wrote:
Handle persistent (VM_BIND) mappings during the request submission
in the execbuf3 path.
v2: Ensure requests wait for bindings to complete.
v3: Remove short term pinning with PIN_VALIDATE flag.
Individualize fences before adding to dma_resv obj.
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@xxxxxxxxx>
Signed-off-by: Andi Shyti <andi.shyti@xxxxxxxxxxxxxxx>
---
.../gpu/drm/i915/gem/i915_gem_execbuffer3.c | 208 +++++++++++++++++-
1 file changed, 207 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c
index a9b4cc44bf66..8120e4c6b7da 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c
@@ -3,6 +3,7 @@
* Copyright © 2022 Intel Corporation
*/
+#include <linux/dma-fence-array.h>
#include <linux/dma-resv.h>
#include <linux/uaccess.h>
@@ -19,6 +20,7 @@
#include "i915_gem_vm_bind.h"
#include "i915_trace.h"
+#define __EXEC3_HAS_PIN BIT_ULL(33)
#define __EXEC3_ENGINE_PINNED BIT_ULL(32)
#define __EXEC3_INTERNAL_FLAGS (~0ull << 32)
@@ -42,7 +44,9 @@
* execlist. Hence, no support for implicit sync.
*
* The new execbuf3 ioctl only works in VM_BIND mode and the VM_BIND mode only
- * works with execbuf3 ioctl for submission.
+ * works with execbuf3 ioctl for submission. All BOs mapped on that VM (through
+ * VM_BIND call) at the time of execbuf3 call are deemed required for that
+ * submission.
*
* The execbuf3 ioctl directly specifies the batch addresses instead of as
* object handles as in execbuf2 ioctl. The execbuf3 ioctl will also not
@@ -58,6 +62,13 @@
* So, a lot of code supporting execbuf2 ioctl, like relocations, VA evictions,
* vma lookup table, implicit sync, vma active reference tracking etc., are not
* applicable for execbuf3 ioctl.
+ *
+ * During each execbuf submission, request fence is added to all VM_BIND mapped
+ * objects with DMA_RESV_USAGE_BOOKKEEP. The DMA_RESV_USAGE_BOOKKEEP usage will
+ * prevent over sync (See enum dma_resv_usage). Note that DRM_I915_GEM_WAIT and
+ * DRM_I915_GEM_BUSY ioctls do not check for DMA_RESV_USAGE_BOOKKEEP usage and
+ * hence should not be used for end of batch check. Instead, the execbuf3
+ * timeline out fence should be used for end of batch check.
*/
/**
@@ -127,6 +138,23 @@ eb_find_vma(struct i915_address_space *vm, u64 addr)
return i915_gem_vm_bind_lookup_vma(vm, va);
}
+static void eb_scoop_unbound_vma_all(struct i915_address_space *vm)
+{
+ struct i915_vma *vma, *vn;
+
+ /**
+ * Move all unbound vmas back into vm_bind_list so that they are
+ * revalidated.
+ */
+ spin_lock(&vm->vm_rebind_lock);
+ list_for_each_entry_safe(vma, vn, &vm->vm_rebind_list, vm_rebind_link) {
+ list_del_init(&vma->vm_rebind_link);
+ if (!list_empty(&vma->vm_bind_link))
+ list_move_tail(&vma->vm_bind_link, &vm->vm_bind_list);
+ }
+ spin_unlock(&vm->vm_rebind_lock);
+}
+
static int eb_lookup_vma_all(struct i915_execbuffer *eb)
{
unsigned int i, current_batch = 0;
@@ -141,14 +169,108 @@ static int eb_lookup_vma_all(struct i915_execbuffer *eb)
++current_batch;
}
+ eb_scoop_unbound_vma_all(eb->context->vm);
+
+ return 0;
+}
+
+static int eb_lock_vma_all(struct i915_execbuffer *eb)
+{
+ struct i915_address_space *vm = eb->context->vm;
+ struct i915_vma *vma;
+ int err;
+
+ err = i915_gem_object_lock(eb->context->vm->root_obj, &eb->ww);
+ if (err)
+ return err;
+
+ list_for_each_entry(vma, &vm->non_priv_vm_bind_list,
+ non_priv_vm_bind_link) {
+ err = i915_gem_object_lock(vma->obj, &eb->ww);
+ if (err)
+ return err;
+ }
+
return 0;
}
+static void eb_release_persistent_vma_all(struct i915_execbuffer *eb)
+{
+ struct i915_address_space *vm = eb->context->vm;
+ struct i915_vma *vma, *vn;
+
+ lockdep_assert_held(&vm->vm_bind_lock);
+
+ if (!(eb->args->flags & __EXEC3_HAS_PIN))
+ return;
+
+ assert_object_held(vm->root_obj);
+
+ list_for_each_entry_safe(vma, vn, &vm->vm_bind_list, vm_bind_link)
+ if (i915_vma_verify_bind_complete(vma))
+ list_move_tail(&vma->vm_bind_link, &vm->vm_bound_list);
+
+ eb->args->flags &= ~__EXEC3_HAS_PIN;
+}
+
static void eb_release_vma_all(struct i915_execbuffer *eb)
{
+ eb_release_persistent_vma_all(eb);
eb_unpin_engine(eb);
}
+static int eb_reserve_fence_for_persistent_vma_all(struct i915_execbuffer *eb)
+{
+ struct i915_address_space *vm = eb->context->vm;
+ u64 num_fences = 1;
+ struct i915_vma *vma;
+ int ret;
+
+ /* Reserve enough slots to accommodate composite fences */
+ if (intel_context_is_parallel(eb->context))
+ num_fences = eb->num_batches;
+
+ ret = dma_resv_reserve_fences(vm->root_obj->base.resv, num_fences);
+ if (ret)
+ return ret;
+
+ list_for_each_entry(vma, &vm->non_priv_vm_bind_list,
+ non_priv_vm_bind_link) {
+ ret = dma_resv_reserve_fences(vma->obj->base.resv, num_fences);
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int eb_validate_persistent_vma_all(struct i915_execbuffer *eb)
+{
+ struct i915_address_space *vm = eb->context->vm;
+ struct i915_vma *vma;
+ int ret = 0;
+
+ lockdep_assert_held(&vm->vm_bind_lock);
+ assert_object_held(vm->root_obj);
+
+ ret = eb_reserve_fence_for_persistent_vma_all(eb);
+ if (ret)
+ return ret;
+
+ list_for_each_entry(vma, &vm->vm_bind_list, vm_bind_link) {
+ u64 pin_flags = vma->start | PIN_OFFSET_FIXED |
+ PIN_USER | PIN_VALIDATE;
Should we also add NOEVICT here and in vm_bind? Or is eviction somehow
still desired in vm_bind world?
+
+ ret = i915_vma_pin_ww(vma, &eb->ww, 0, 0, pin_flags);
+ if (ret)
+ break;
+
+ eb->args->flags |= __EXEC3_HAS_PIN;
+ }
+
+ return ret;
+}
+
/*
* 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
@@ -160,13 +282,80 @@ static void eb_release_vma_all(struct i915_execbuffer *eb)
*/
#define for_each_batch_create_order(_eb) \
for (unsigned int i = 0; i < (_eb)->num_batches; ++i)
+#define for_each_batch_add_order(_eb) \
+ for (int i = (_eb)->num_batches - 1; i >= 0; --i)
+
+static void __eb_persistent_add_shared_fence(struct drm_i915_gem_object *obj,
+ struct dma_fence *fence)
+{
+ struct dma_fence *curr;
+ int idx;
+
+ dma_fence_array_for_each(curr, idx, fence)
+ dma_resv_add_fence(obj->base.resv, curr,
+ DMA_RESV_USAGE_BOOKKEEP);
+
+ obj->write_domain = 0;
+ obj->read_domains |= I915_GEM_GPU_DOMAINS;
+ obj->mm.dirty = true;
+}
+
+static void eb_persistent_add_shared_fence(struct i915_execbuffer *eb)
+{
+ struct i915_address_space *vm = eb->context->vm;
+ struct dma_fence *fence;
+ struct i915_vma *vma;
+
+ fence = eb->composite_fence ? eb->composite_fence :
+ &eb->requests[0]->fence;
+
+ __eb_persistent_add_shared_fence(vm->root_obj, fence);
+ list_for_each_entry(vma, &vm->non_priv_vm_bind_list,
+ non_priv_vm_bind_link)
+ __eb_persistent_add_shared_fence(vma->obj, fence);
+}
+
+static void eb_move_all_persistent_vma_to_active(struct i915_execbuffer *eb)
+{
+ /* Add fence to BOs dma-resv fence list */
+ eb_persistent_add_shared_fence(eb);
+}
static int eb_move_to_gpu(struct i915_execbuffer *eb)
{
+ struct i915_address_space *vm = eb->context->vm;
+ struct i915_vma *vma;
+ int err = 0;
+
+ lockdep_assert_held(&vm->vm_bind_lock);
+ assert_object_held(vm->root_obj);
+
+ eb_move_all_persistent_vma_to_active(eb);
+
+ list_for_each_entry(vma, &vm->vm_bind_list, vm_bind_link) {
+ for_each_batch_add_order(eb) {
+ if (!eb->requests[i])
+ continue;
+
+ err = i915_request_await_bind(eb->requests[i], vma);
+ if (err)
+ goto err_skip;
+ }
+ }
+
/* Unconditionally flush any chipset caches (for streaming writes). */
intel_gt_chipset_flush(eb->gt);
return 0;
+
+err_skip:
+ for_each_batch_create_order(eb) {
+ if (!eb->requests[i])
+ break;
+
+ i915_request_set_error_once(eb->requests[i], err);
+ }
+ return err;
}
static int eb_request_submit(struct i915_execbuffer *eb,
@@ -483,6 +672,7 @@ 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);
@@ -499,6 +689,22 @@ i915_gem_do_execbuffer(struct drm_device *dev,
/* only throttle once, even if we didn't need to throttle */
throttle = false;
+ err = eb_lock_vma_all(&eb);
+ if (err)
+ goto err_validate;
+
+ /**
+ * No object unbinds possible once the objects are locked. So,
+ * check for any unbinds here, which needs to be scooped up.
+ */
+ if (!list_empty(&eb.context->vm->vm_rebind_list)) {
+ eb_release_vma_all(&eb);
+ 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);
