[PATCH v4 16/17] drm/i915/vm_bind: userptr dma-resv changes

Niranjana Vishwanathapura niranjana.vishwanathapura at intel.com
Thu Oct 20 16:39:35 UTC 2022


On Thu, Oct 20, 2022 at 05:29:45PM +0100, Matthew Auld wrote:
>On 18/10/2022 08:16, Niranjana Vishwanathapura wrote:
>>For persistent (vm_bind) vmas of userptr BOs, handle the user
>>page pinning by using the i915_gem_object_userptr_submit_init()
>>/done() functions
>>
>>v2: Do not double add vma to vm->userptr_invalidated_list
>>
>>Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
>>Signed-off-by: Andi Shyti <andi.shyti at linux.intel.com>
>>---
>>  .../gpu/drm/i915/gem/i915_gem_execbuffer3.c   | 80 +++++++++++++++++++
>>  drivers/gpu/drm/i915/gem/i915_gem_userptr.c   | 19 +++++
>>  .../drm/i915/gem/i915_gem_vm_bind_object.c    | 15 ++++
>>  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, 122 insertions(+)
>>
>>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c
>>index 8120e4c6b7da..3f1157dd7fc2 100644
>>--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c
>>+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer3.c
>>@@ -20,6 +20,7 @@
>>  #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)
>>@@ -142,6 +143,21 @@ static void eb_scoop_unbound_vma_all(struct i915_address_space *vm)
>>  {
>>  	struct i915_vma *vma, *vn;
>>+#ifdef CONFIG_MMU_NOTIFIER
>>+	/**
>
>Not proper kernel-doc AFAIK.

Ok, will use single asterisk above.

>
>>+	 * Move all invalidated userptr vmas back into vm_bind_list so that
>>+	 * they are looked up and revalidated.
>>+	 */
>>+	spin_lock(&vm->userptr_invalidated_lock);
>>+	list_for_each_entry_safe(vma, vn, &vm->userptr_invalidated_list,
>>+				 userptr_invalidated_link) {
>>+		list_del_init(&vma->userptr_invalidated_link);
>>+		if (!list_empty(&vma->vm_bind_link))
>>+			list_move_tail(&vma->vm_bind_link, &vm->vm_bind_list);
>>+	}
>>+	spin_unlock(&vm->userptr_invalidated_lock);
>>+#endif
>>+
>>  	/**
>>  	 * Move all unbound vmas back into vm_bind_list so that they are
>>  	 * revalidated.
>>@@ -155,10 +171,47 @@ 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_bind_list, vm_bind_link) {
>>+		if (!i915_gem_object_is_userptr(vma->obj))
>>+			continue;
>>+
>>+		err = i915_gem_object_userptr_submit_init(vma->obj);
>>+		if (err)
>>+			return err;
>>+
>>+		/**
>>+		 * The above submit_init() call does the object unbind and
>>+		 * hence adds vma into vm_rebind_list. Remove it from that
>>+		 * list as it is already scooped for revalidation.
>>+		 */
>
>Ditto.

ok

>
>>+		spin_lock(&vm->vm_rebind_lock);
>>+		if (!list_empty(&vma->vm_rebind_link))
>>+			list_del_init(&vma->vm_rebind_link);
>>+		spin_unlock(&vm->vm_rebind_lock);
>>+
>>+		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 +224,10 @@ static int eb_lookup_vma_all(struct i915_execbuffer *eb)
>>  	eb_scoop_unbound_vma_all(eb->context->vm);
>>+	err = eb_lookup_persistent_userptr_vmas(eb);
>>+	if (err)
>>+		return err;
>>+
>>  	return 0;
>>  }
>>@@ -343,6 +400,29 @@ static int eb_move_to_gpu(struct i915_execbuffer *eb)
>>  		}
>>  	}
>>+#ifdef CONFIG_MMU_NOTIFIER
>>+	/* Check for further userptr invalidations */
>>+	spin_lock(&vm->userptr_invalidated_lock);
>>+	if (!list_empty(&vm->userptr_invalidated_list))
>>+		err = -EAGAIN;
>>+	spin_unlock(&vm->userptr_invalidated_lock);
>
>After dropping the lock here, the invalidated_list might no longer be 
>empty? Is that not possible, or somehow not a concern?
>

It should be fine as we have already added the fence to dma-resv object above.
Any subsequent mmu invalidations will end up waiting for request to finish
(similar to case where mmu invalidation gets called after request is submitted).

>>+
>>+	if (!err && (eb->args->flags & __EXEC3_USERPTR_USED)) {
>>+		read_lock(&eb->i915->mm.notifier_lock);
>>+		list_for_each_entry(vma, &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 (unlikely(err))
>>+		goto err_skip;
>>+
>>  	/* Unconditionally flush any chipset caches (for streaming writes). */
>>  	intel_gt_chipset_flush(eb->gt);
>>diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
>>index b7e24476a0fd..3e88fd4d46b6 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 +86,24 @@ static bool i915_gem_userptr_invalidate(struct mmu_interval_notifier *mni,
>>  	if (current->flags & PF_EXITING)
>>  		return true;
>>+	/**
>>+	 * Add persistent vmas into userptr_invalidated list for relookup
>>+	 * and revalidation.
>>+	 */
>
>Ditto.

Ok

Thanks,
Niranjana

>
>>+	spin_lock(&obj->vma.lock);
>>+	list_for_each_entry(vma, &obj->vma.list, obj_link) {
>>+		if (!i915_vma_is_persistent(vma))
>>+			continue;
>>+
>>+		spin_lock(&vma->vm->userptr_invalidated_lock);
>>+		if (list_empty(&vma->userptr_invalidated_link) &&
>>+		    !i915_vma_is_purged(vma))
>>+			list_add_tail(&vma->userptr_invalidated_link,
>>+				      &vma->vm->userptr_invalidated_list);
>>+		spin_unlock(&vma->vm->userptr_invalidated_lock);
>>+	}
>>+	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 63889ba00183..19071493355c 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
>>@@ -299,6 +299,12 @@ 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;
>>@@ -327,6 +333,15 @@ static int i915_gem_vm_bind_obj(struct i915_address_space *vm,
>>  		if (ret)
>>  			continue;
>>+#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)
>>+				continue;
>>+		}
>>+#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 ebf8fc3a4603..50648ab9214a 100644
>>--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
>>+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
>>@@ -292,6 +292,8 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
>>  	INIT_LIST_HEAD(&vm->non_priv_vm_bind_list);
>>  	INIT_LIST_HEAD(&vm->vm_rebind_list);
>>  	spin_lock_init(&vm->vm_rebind_lock);
>>+	spin_lock_init(&vm->userptr_invalidated_lock);
>>+	INIT_LIST_HEAD(&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 384d1ee7c68d..1ade95b2a0fa 100644
>>--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
>>+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
>>@@ -270,6 +270,10 @@ struct i915_address_space {
>>  	struct list_head vm_rebind_list;
>>  	/* @vm_rebind_lock: protects vm_rebound_list */
>>  	spinlock_t vm_rebind_lock;
>>+	/* @userptr_invalidated_list: list of invalidated userptr vmas */
>>+	struct list_head userptr_invalidated_list;
>>+	/* @userptr_invalidated_lock: protects userptr_invalidated_list */
>>+	spinlock_t 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 2c740500ac1b..8e562e07d4a7 100644
>>--- a/drivers/gpu/drm/i915/i915_vma_types.h
>>+++ b/drivers/gpu/drm/i915/i915_vma_types.h
>>@@ -307,6 +307,8 @@ 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 */
>>+	/*@userptr_invalidated_link: link to the vm->userptr_invalidated_list */
>>+	struct list_head userptr_invalidated_link;
>>  	/** Timeline fence for vm_bind completion notification */
>>  	struct {


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