[RFC v4 06/14] drm/i915/vm_bind: Handle persistent vmas

Niranjana Vishwanathapura niranjana.vishwanathapura at intel.com
Wed Sep 21 07:09:37 UTC 2022


Treat VM_BIND vmas as persistent across execbuf ioctl calls and handle
them during the request submission in the execbuff path.

Support eviction by maintaining a list of evicted persistent vmas
for rebinding during next submission.

Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
Signed-off-by: Andi Shyti <andi.shyti at linux.intel.com>
---
 .../drm/i915/gem/i915_gem_vm_bind_object.c    |  7 +++
 drivers/gpu/drm/i915/gt/intel_gtt.c           |  2 +
 drivers/gpu/drm/i915/gt/intel_gtt.h           |  4 ++
 drivers/gpu/drm/i915/i915_gem_gtt.c           | 39 ++++++++++++++++
 drivers/gpu/drm/i915/i915_gem_gtt.h           |  3 ++
 drivers/gpu/drm/i915/i915_vma.c               | 46 +++++++++++++++++++
 drivers/gpu/drm/i915/i915_vma.h               | 45 +++++++++++++-----
 drivers/gpu/drm/i915/i915_vma_types.h         | 17 +++++++
 8 files changed, 151 insertions(+), 12 deletions(-)

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 7ca6a41fc981..236f901b8b9c 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
@@ -91,6 +91,12 @@ static void i915_gem_vm_bind_remove(struct i915_vma *vma, bool release_obj)
 {
 	lockdep_assert_held(&vma->vm->vm_bind_lock);
 
+	spin_lock(&vma->vm->vm_rebind_lock);
+	if (!list_empty(&vma->vm_rebind_link))
+		list_del_init(&vma->vm_rebind_link);
+	i915_vma_set_purged(vma);
+	spin_unlock(&vma->vm->vm_rebind_lock);
+
 	list_del_init(&vma->vm_bind_link);
 	list_del_init(&vma->non_priv_vm_bind_link);
 	i915_vm_bind_it_remove(vma, &vma->vm->va);
@@ -181,6 +187,7 @@ static struct i915_vma *vm_bind_get_vma(struct i915_address_space *vm,
 
 	vma->start = va->start;
 	vma->last = va->start + va->length - 1;
+	i915_vma_set_persistent(vma);
 
 	return vma;
 }
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index da4f9dee0397..6db31197fa87 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -296,6 +296,8 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
 	INIT_LIST_HEAD(&vm->non_priv_vm_bind_list);
 	vm->root_obj = i915_gem_object_create_internal(vm->i915, PAGE_SIZE);
 	GEM_BUG_ON(IS_ERR(vm->root_obj));
+	INIT_LIST_HEAD(&vm->vm_rebind_list);
+	spin_lock_init(&vm->vm_rebind_lock);
 }
 
 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 3f2e87d3bf34..b73d35b4e05d 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
@@ -273,6 +273,10 @@ struct i915_address_space {
 	struct list_head vm_bind_list;
 	/** @vm_bound_list: List of vm_binding completed */
 	struct list_head vm_bound_list;
+	/* @vm_rebind_list: list of vmas to be rebinded */
+	struct list_head vm_rebind_list;
+	/* @vm_rebind_lock: protects vm_rebound_list */
+	spinlock_t vm_rebind_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_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 329ff75b80b9..b7d0844de561 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -25,6 +25,45 @@
 #include "i915_trace.h"
 #include "i915_vgpu.h"
 
+/**
+ * i915_vm_sync() - Wait until address space is not in use
+ * @vm: address space
+ *
+ * Waits until all requests using the address space are complete.
+ *
+ * Returns: 0 if success, -ve err code upon failure
+ */
+int i915_vm_sync(struct i915_address_space *vm)
+{
+	int ret;
+
+	/* Wait for all requests under this vm to finish */
+	ret = dma_resv_wait_timeout(vm->root_obj->base.resv,
+				    DMA_RESV_USAGE_BOOKKEEP, false,
+				    MAX_SCHEDULE_TIMEOUT);
+	if (ret < 0)
+		return ret;
+	else if (ret > 0)
+		return 0;
+	else
+		return -ETIMEDOUT;
+}
+
+/**
+ * i915_vm_is_active() - Check if address space is being used
+ * @vm: address space
+ *
+ * Check if any request using the specified address space is
+ * active.
+ *
+ * Returns: true if address space is active, false otherwise.
+ */
+bool i915_vm_is_active(const struct i915_address_space *vm)
+{
+	return !dma_resv_test_signaled(vm->root_obj->base.resv,
+				       DMA_RESV_USAGE_BOOKKEEP);
+}
+
 int i915_gem_gtt_prepare_pages(struct drm_i915_gem_object *obj,
 			       struct sg_table *pages)
 {
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 8c2f57eb5dda..a5bbdc59d9df 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -51,4 +51,7 @@ int i915_gem_gtt_insert(struct i915_address_space *vm,
 
 #define PIN_OFFSET_MASK		I915_GTT_PAGE_MASK
 
+int i915_vm_sync(struct i915_address_space *vm);
+bool i915_vm_is_active(const struct i915_address_space *vm);
+
 #endif
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index aa332ad69ec2..ff216e9a2c8d 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -237,6 +237,7 @@ vma_create(struct drm_i915_gem_object *obj,
 
 	INIT_LIST_HEAD(&vma->vm_bind_link);
 	INIT_LIST_HEAD(&vma->non_priv_vm_bind_link);
+	INIT_LIST_HEAD(&vma->vm_rebind_link);
 	return vma;
 
 err_unlock:
@@ -387,6 +388,24 @@ int i915_vma_wait_for_bind(struct i915_vma *vma)
 	return err;
 }
 
+/**
+ * i915_vma_sync() - Wait for the vma to be idle
+ * @vma: vma to be tested
+ *
+ * Returns 0 on success and error code on failure
+ */
+int i915_vma_sync(struct i915_vma *vma)
+{
+	int ret;
+
+	/* Wait for the asynchronous bindings and pending GPU reads */
+	ret = i915_active_wait(&vma->active);
+	if (ret || !i915_vma_is_persistent(vma) || i915_vma_is_purged(vma))
+		return ret;
+
+	return i915_vm_sync(vma->vm);
+}
+
 #if IS_ENABLED(CONFIG_DRM_I915_DEBUG_GEM)
 static int i915_vma_verify_bind_complete(struct i915_vma *vma)
 {
@@ -1654,6 +1673,13 @@ static void force_unbind(struct i915_vma *vma)
 	if (!drm_mm_node_allocated(&vma->node))
 		return;
 
+	/*
+	 * Mark persistent vma as purged to avoid it waiting
+	 * for VM to be released.
+	 */
+	if (i915_vma_is_persistent(vma))
+		i915_vma_set_purged(vma);
+
 	atomic_and(~I915_VMA_PIN_MASK, &vma->flags);
 	WARN_ON(__i915_vma_unbind(vma));
 	GEM_BUG_ON(drm_mm_node_allocated(&vma->node));
@@ -1846,6 +1872,8 @@ int _i915_vma_move_to_active(struct i915_vma *vma,
 	int err;
 
 	assert_object_held(obj);
+	if (i915_vma_is_persistent(vma))
+		return -EINVAL;
 
 	GEM_BUG_ON(!vma->pages);
 
@@ -2015,6 +2043,16 @@ int __i915_vma_unbind(struct i915_vma *vma)
 	__i915_vma_evict(vma, false);
 
 	drm_mm_remove_node(&vma->node); /* pairs with i915_vma_release() */
+
+	if (i915_vma_is_persistent(vma)) {
+		spin_lock(&vma->vm->vm_rebind_lock);
+		if (list_empty(&vma->vm_rebind_link) &&
+		    !i915_vma_is_purged(vma))
+			list_add_tail(&vma->vm_rebind_link,
+				      &vma->vm->vm_rebind_list);
+		spin_unlock(&vma->vm->vm_rebind_lock);
+	}
+
 	return 0;
 }
 
@@ -2046,6 +2084,14 @@ static struct dma_fence *__i915_vma_unbind_async(struct i915_vma *vma)
 		return ERR_PTR(-EBUSY);
 	}
 
+	if (__i915_sw_fence_await_reservation(&vma->resource->chain,
+					      vma->obj->base.resv,
+					      DMA_RESV_USAGE_BOOKKEEP,
+					      i915_fence_timeout(vma->vm->i915),
+					      I915_FENCE_GFP) < 0) {
+		return ERR_PTR(-EBUSY);
+	}
+
 	fence = __i915_vma_evict(vma, true);
 
 	drm_mm_remove_node(&vma->node); /* pairs with i915_vma_release() */
diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 6feef0305fe1..aa536c9ce472 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -47,12 +47,6 @@ i915_vma_instance(struct drm_i915_gem_object *obj,
 
 void i915_vma_unpin_and_release(struct i915_vma **p_vma, unsigned int flags);
 #define I915_VMA_RELEASE_MAP BIT(0)
-
-static inline bool i915_vma_is_active(const struct i915_vma *vma)
-{
-	return !i915_active_is_idle(&vma->active);
-}
-
 /* do not reserve memory to prevent deadlocks */
 #define __EXEC_OBJECT_NO_RESERVE BIT(31)
 
@@ -138,6 +132,38 @@ static inline u32 i915_ggtt_pin_bias(struct i915_vma *vma)
 	return i915_vm_to_ggtt(vma->vm)->pin_bias;
 }
 
+static inline bool i915_vma_is_persistent(const struct i915_vma *vma)
+{
+	return test_bit(I915_VMA_PERSISTENT_BIT, __i915_vma_flags(vma));
+}
+
+static inline void i915_vma_set_persistent(struct i915_vma *vma)
+{
+	set_bit(I915_VMA_PERSISTENT_BIT, __i915_vma_flags(vma));
+}
+
+static inline bool i915_vma_is_purged(const struct i915_vma *vma)
+{
+	return test_bit(I915_VMA_PURGED_BIT, __i915_vma_flags(vma));
+}
+
+static inline void i915_vma_set_purged(struct i915_vma *vma)
+{
+	set_bit(I915_VMA_PURGED_BIT, __i915_vma_flags(vma));
+}
+
+static inline bool i915_vma_is_active(const struct i915_vma *vma)
+{
+	if (i915_vma_is_persistent(vma)) {
+		if (i915_vma_is_purged(vma))
+			return false;
+
+		return i915_vm_is_active(vma->vm);
+	}
+
+	return !i915_active_is_idle(&vma->active);
+}
+
 static inline struct i915_vma *i915_vma_get(struct i915_vma *vma)
 {
 	i915_gem_object_get(vma->obj);
@@ -406,12 +432,7 @@ void i915_vma_make_shrinkable(struct i915_vma *vma);
 void i915_vma_make_purgeable(struct i915_vma *vma);
 
 int i915_vma_wait_for_bind(struct i915_vma *vma);
-
-static inline int i915_vma_sync(struct i915_vma *vma)
-{
-	/* Wait for the asynchronous bindings and pending GPU reads */
-	return i915_active_wait(&vma->active);
-}
+int i915_vma_sync(struct i915_vma *vma);
 
 /**
  * i915_vma_get_current_resource - Get the current resource of the vma
diff --git a/drivers/gpu/drm/i915/i915_vma_types.h b/drivers/gpu/drm/i915/i915_vma_types.h
index 6d727c2d9802..d21bf97febaa 100644
--- a/drivers/gpu/drm/i915/i915_vma_types.h
+++ b/drivers/gpu/drm/i915/i915_vma_types.h
@@ -264,6 +264,21 @@ struct i915_vma {
 #define I915_VMA_SCANOUT_BIT	17
 #define I915_VMA_SCANOUT	((int)BIT(I915_VMA_SCANOUT_BIT))
 
+  /**
+   * I915_VMA_PERSISTENT_BIT:
+   * The vma is persistent (created with VM_BIND call).
+   *
+   * I915_VMA_PURGED_BIT:
+   * The persistent vma is force unbound either due to VM_UNBIND call
+   * from UMD or VM is released. Do not check/wait for VM activeness
+   * in i915_vma_is_active() and i915_vma_sync() calls.
+   */
+#define I915_VMA_PERSISTENT_BIT	19
+#define I915_VMA_PURGED_BIT	20
+
+#define I915_VMA_PERSISTENT	((int)BIT(I915_VMA_PERSISTENT_BIT))
+#define I915_VMA_PURGED		((int)BIT(I915_VMA_PURGED_BIT))
+
 	struct i915_active active;
 
 #define I915_VMA_PAGES_BIAS 24
@@ -293,6 +308,8 @@ struct i915_vma {
 	struct list_head vm_bind_link;
 	/* @non_priv_vm_bind_link: Link in non-private persistent VMA list */
 	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 */
 
 	/** Interval tree structures for persistent vma */
 
-- 
2.21.0.rc0.32.g243a4c7e27



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