[RFC 05/10] drm/i915/vm_bind: Handle persistent vmas

[Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>]

Treat VM_BIND vmas as persistent 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@intel.com>
---
 drivers/gpu/drm/i915/gem/i915_gem_object.c    |  1 +
 drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h   |  3 +
 .../drm/i915/gem/i915_gem_vm_bind_object.c    | 12 ++-
 drivers/gpu/drm/i915/gt/intel_gtt.c           |  2 +
 drivers/gpu/drm/i915/gt/intel_gtt.h           |  2 +
 drivers/gpu/drm/i915/i915_gem_gtt.h           | 22 ++++++
 drivers/gpu/drm/i915/i915_vma.c               | 32 +++++++-
 drivers/gpu/drm/i915/i915_vma.h               | 78 +++++++++++++++++--
 drivers/gpu/drm/i915/i915_vma_types.h         | 23 ++++++
 9 files changed, 163 insertions(+), 12 deletions(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
index ccec4055fde3..5121f02ba95c 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -38,6 +38,7 @@
 #include "i915_gem_mman.h"
 #include "i915_gem_object.h"
 #include "i915_gem_ttm.h"
+#include "i915_gem_vm_bind.h"
 #include "i915_memcpy.h"
 #include "i915_trace.h"
 
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
index 849bf3c1061e..eaadf5a6ab09 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
@@ -6,6 +6,7 @@
 #ifndef __I915_GEM_VM_BIND_H
 #define __I915_GEM_VM_BIND_H
 
+#include <linux/dma-resv.h>
 #include "i915_drv.h"
 
 #define assert_vm_bind_held(vm)   lockdep_assert_held(&(vm)->vm_bind_lock)
@@ -26,6 +27,8 @@ static inline void i915_gem_vm_bind_unlock(struct i915_address_space *vm)
 	mutex_unlock(&vm->vm_bind_lock);
 }
 
+#define assert_vm_priv_held(vm)   assert_object_held((vm)->root_obj)
+
 static inline int i915_gem_vm_priv_lock(struct i915_address_space *vm,
 					struct i915_gem_ww_ctx *ww)
 {
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 96f139cc8060..1a8efa83547f 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
@@ -85,6 +85,13 @@ void i915_gem_vm_bind_remove(struct i915_vma *vma, bool release_obj)
 {
 	assert_vm_bind_held(vma->vm);
 
+	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);
+	i915_vma_set_freed(vma);
+	spin_unlock(&vma->vm->vm_rebind_lock);
+
 	if (!list_empty(&vma->vm_bind_link)) {
 		list_del_init(&vma->vm_bind_link);
 		list_del_init(&vma->non_priv_vm_bind_link);
@@ -220,6 +227,7 @@ 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;
 }
@@ -304,8 +312,10 @@ int i915_gem_vm_bind_obj(struct i915_address_space *vm,
 
 	i915_vm_bind_put_fence(vma);
 put_vma:
-	if (ret)
+	if (ret) {
+		i915_vma_set_freed(vma);
 		i915_vma_destroy(vma);
+	}
 
 	i915_gem_ww_ctx_fini(&ww);
 unlock_vm:
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index df0a8459c3c6..55d5389b2c6c 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -293,6 +293,8 @@ 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 f538ce9115c9..fe5485c4a1cd 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
@@ -265,6 +265,8 @@ struct i915_address_space {
 	struct mutex vm_bind_lock;  /* Protects vm_bind lists */
 	struct list_head vm_bind_list;
 	struct list_head vm_bound_list;
+	struct list_head vm_rebind_list;
+	spinlock_t vm_rebind_lock;   /* Protects vm_rebind_list */
 	/* 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.h b/drivers/gpu/drm/i915/i915_gem_gtt.h
index 8c2f57eb5dda..09b89d1913fc 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.h
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
@@ -51,4 +51,26 @@ int i915_gem_gtt_insert(struct i915_address_space *vm,
 
 #define PIN_OFFSET_MASK		I915_GTT_PAGE_MASK
 
+static inline 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;
+}
+
+static inline 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);
+}
+
 #endif
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index 6737236b7884..6adb013579be 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:
@@ -1622,7 +1623,8 @@ void i915_vma_close(struct i915_vma *vma)
 	if (atomic_dec_and_lock_irqsave(&vma->open_count,
 					&gt->closed_lock,
 					flags)) {
-		__vma_close(vma, gt);
+		if (!i915_vma_is_persistent(vma))
+			__vma_close(vma, gt);
 		spin_unlock_irqrestore(&gt->closed_lock, flags);
 	}
 }
@@ -1647,6 +1649,13 @@ 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));
@@ -1666,9 +1675,12 @@ static void release_references(struct i915_vma *vma, bool vm_ddestroy)
 
 	spin_unlock(&obj->vma.lock);
 
-	i915_gem_vm_bind_lock(vma->vm);
-	i915_gem_vm_bind_remove(vma, true);
-	i915_gem_vm_bind_unlock(vma->vm);
+	if (i915_vma_is_persistent(vma) &&
+	    !i915_vma_is_freed(vma)) {
+		i915_gem_vm_bind_lock(vma->vm);
+		i915_gem_vm_bind_remove(vma, true);
+		i915_gem_vm_bind_unlock(vma->vm);
+	}
 
 	spin_lock_irq(&gt->closed_lock);
 	__i915_vma_remove_closed(vma);
@@ -1839,6 +1851,8 @@ 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);
 
@@ -1999,6 +2013,16 @@ 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;
 }
 
diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index dcb49f79ff7e..6c1369a40e03 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 +132,48 @@ 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_freed(const struct i915_vma *vma)
+{
+	return test_bit(I915_VMA_FREED_BIT, __i915_vma_flags(vma));
+}
+
+static inline void i915_vma_set_freed(struct i915_vma *vma)
+{
+	set_bit(I915_VMA_FREED_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);
@@ -408,8 +444,36 @@ int i915_vma_wait_for_bind(struct i915_vma *vma);
 
 static inline int i915_vma_sync(struct i915_vma *vma)
 {
+	int ret;
+
 	/* Wait for the asynchronous bindings and pending GPU reads */
-	return i915_active_wait(&vma->active);
+	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);
+}
+
+static inline bool i915_vma_is_bind_complete(struct i915_vma *vma)
+{
+	/* Ensure vma bind is initiated */
+	if (!i915_vma_is_bound(vma, I915_VMA_BIND_MASK))
+		return false;
+
+	/* Ensure any binding started is complete */
+	if (rcu_access_pointer(vma->active.excl.fence)) {
+		struct dma_fence *fence;
+
+		rcu_read_lock();
+		fence = dma_fence_get_rcu_safe(&vma->active.excl.fence);
+		rcu_read_unlock();
+		if (fence) {
+			dma_fence_put(fence);
+			return false;
+		}
+	}
+
+	return true;
 }
 
 /**
diff --git a/drivers/gpu/drm/i915/i915_vma_types.h b/drivers/gpu/drm/i915/i915_vma_types.h
index 7d830a6a0b51..405c82e1bc30 100644
--- a/drivers/gpu/drm/i915/i915_vma_types.h
+++ b/drivers/gpu/drm/i915/i915_vma_types.h
@@ -264,6 +264,28 @@ 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.
+   *
+   * I915_VMA_FREED_BIT:
+   * The persistent vma is being released by UMD via VM_UNBIND call.
+   * While releasing the vma, do not take VM_BIND lock as VM_UNBIND call
+   * already holds the lock.
+   */
+#define I915_VMA_PERSISTENT_BIT	19
+#define I915_VMA_PURGED_BIT	20
+#define I915_VMA_FREED_BIT	21
+
+#define I915_VMA_PERSISTENT	((int)BIT(I915_VMA_PERSISTENT_BIT))
+#define I915_VMA_PURGED		((int)BIT(I915_VMA_PURGED_BIT))
+#define I915_VMA_FREED		((int)BIT(I915_VMA_FREED_BIT))
+
 	struct i915_active active;
 
 #define I915_VMA_PAGES_BIAS 24
@@ -292,6 +314,7 @@ struct i915_vma {
 	struct list_head vm_bind_link; /* Link in persistent VMA list */
 	/* Link in non-private persistent VMA list */
 	struct list_head non_priv_vm_bind_link;
+	struct list_head vm_rebind_link; /* Link in vm_rebind_list */
 
 	/** Timeline fence for vm_bind completion notification */
 	struct {
-- 
2.21.0.rc0.32.g243a4c7e27