drm/i915/vm_bind: Bind and unbind mappings

Bind and unbind the mappings upon VM_BIND and VM_UNBIND calls.

Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura@intel.com>
Signed-off-by: Prathap Kumar Valsan <prathap.kumar.valsan@intel.com>

11 files changed, 318 insertions, 10 deletions

diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
index 522ef9b4aff3..4e1627e96c6e 100644
--- a/drivers/gpu/drm/i915/Makefile
+++ b/drivers/gpu/drm/i915/Makefile
@@ -165,6 +165,7 @@ gem-y += \
 	gem/i915_gem_ttm_move.o \
 	gem/i915_gem_ttm_pm.o \
 	gem/i915_gem_userptr.o \
+	gem/i915_gem_vm_bind_object.o \
 	gem/i915_gem_wait.o \
 	gem/i915_gemfs.o
 i915-y += \
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_create.c b/drivers/gpu/drm/i915/gem/i915_gem_create.c
index 33673fe7ee0a..927a87e5ec59 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_create.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_create.c
@@ -15,10 +15,10 @@
 #include "i915_trace.h"
 #include "i915_user_extensions.h"
 
-static u32 object_max_page_size(struct intel_memory_region **placements,
-				unsigned int n_placements)
+u32 i915_gem_object_max_page_size(struct intel_memory_region **placements,
+				  unsigned int n_placements)
 {
-	u32 max_page_size = 0;
+	u32 max_page_size = I915_GTT_PAGE_SIZE_4K;
 	int i;
 
 	for (i = 0; i < n_placements; i++) {
@@ -28,7 +28,6 @@ static u32 object_max_page_size(struct intel_memory_region **placements,
 		max_page_size = max_t(u32, max_page_size, mr->min_page_size);
 	}
 
-	GEM_BUG_ON(!max_page_size);
 	return max_page_size;
 }
 
@@ -99,7 +98,8 @@ __i915_gem_object_create_user_ext(struct drm_i915_private *i915, u64 size,
 
 	i915_gem_flush_free_objects(i915);
 
-	size = round_up(size, object_max_page_size(placements, n_placements));
+	size = round_up(size, i915_gem_object_max_page_size(placements,
+							    n_placements));
 	if (size == 0)
 		return ERR_PTR(-EINVAL);
 
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index 6f0a3ce35567..650de2224843 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -47,6 +47,8 @@ static inline bool i915_gem_object_size_2big(u64 size)
 }
 
 void i915_gem_init__objects(struct drm_i915_private *i915);
+u32 i915_gem_object_max_page_size(struct intel_memory_region **placements,
+				  unsigned int n_placements);
 
 void i915_objects_module_exit(void);
 int i915_objects_module_init(void);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
new file mode 100644
index 000000000000..642cdb559f17
--- /dev/null
+++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind.h
@@ -0,0 +1,38 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#ifndef __I915_GEM_VM_BIND_H
+#define __I915_GEM_VM_BIND_H
+
+#include "i915_drv.h"
+
+#define assert_vm_bind_held(vm)   lockdep_assert_held(&(vm)->vm_bind_lock)
+
+static inline void i915_gem_vm_bind_lock(struct i915_address_space *vm)
+{
+	mutex_lock(&vm->vm_bind_lock);
+}
+
+static inline int
+i915_gem_vm_bind_lock_interruptible(struct i915_address_space *vm)
+{
+	return mutex_lock_interruptible(&vm->vm_bind_lock);
+}
+
+static inline void i915_gem_vm_bind_unlock(struct i915_address_space *vm)
+{
+	mutex_unlock(&vm->vm_bind_lock);
+}
+
+struct i915_vma *
+i915_gem_vm_bind_lookup_vma(struct i915_address_space *vm, u64 va);
+void i915_gem_vm_bind_remove(struct i915_vma *vma, bool release_obj);
+int i915_gem_vm_bind_obj(struct i915_address_space *vm,
+			 struct drm_i915_gem_vm_bind *va,
+			 struct drm_file *file);
+int i915_gem_vm_unbind_obj(struct i915_address_space *vm,
+			   struct drm_i915_gem_vm_unbind *va);
+
+#endif /* __I915_GEM_VM_BIND_H */
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
new file mode 100644
index 000000000000..43ceb4dcca6c
--- /dev/null
+++ b/drivers/gpu/drm/i915/gem/i915_gem_vm_bind_object.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include <linux/interval_tree_generic.h>
+
+#include "gem/i915_gem_vm_bind.h"
+#include "gt/gen8_engine_cs.h"
+
+#include "i915_drv.h"
+#include "i915_gem_gtt.h"
+
+#define START(node) ((node)->start)
+#define LAST(node) ((node)->last)
+
+INTERVAL_TREE_DEFINE(struct i915_vma, rb, u64, __subtree_last,
+		     START, LAST, static inline, i915_vm_bind_it)
+
+#undef START
+#undef LAST
+
+/**
+ * DOC: VM_BIND/UNBIND ioctls
+ *
+ * DRM_I915_GEM_VM_BIND/UNBIND ioctls allows UMD to bind/unbind GEM buffer
+ * objects (BOs) or sections of a BOs at specified GPU virtual addresses on a
+ * specified address space (VM). Multiple mappings can map to the same physical
+ * pages of an object (aliasing). These mappings (also referred to as persistent
+ * mappings) will be persistent across multiple GPU submissions (execbuf calls)
+ * issued by the UMD, without user having to provide a list of all required
+ * mappings during each submission (as required by older execbuf mode).
+ *
+ * The VM_BIND/UNBIND calls allow UMDs to request a timeline out fence for
+ * signaling the completion of bind/unbind operation.
+ *
+ * VM_BIND feature is advertised to user via I915_PARAM_VM_BIND_VERSION.
+ * User has to opt-in for VM_BIND mode of binding for an address space (VM)
+ * during VM creation time via I915_VM_CREATE_FLAGS_USE_VM_BIND extension.
+ *
+ * VM_BIND/UNBIND ioctl calls executed on different CPU threads concurrently
+ * are not ordered. Furthermore, parts of the VM_BIND/UNBIND operations can be
+ * done asynchronously, when valid out fence is specified.
+ *
+ * VM_BIND locking order is as below.
+ *
+ * 1) Lock-A: A vm_bind mutex will protect vm_bind lists. This lock is taken in
+ *    vm_bind/vm_unbind ioctl calls, in the execbuf path and while releasing the
+ *    mapping.
+ *
+ *    In future, when GPU page faults are supported, we can potentially use a
+ *    rwsem instead, so that multiple page fault handlers can take the read
+ *    side lock to lookup the mapping and hence can run in parallel.
+ *    The older execbuf mode of binding do not need this lock.
+ *
+ * 2) Lock-B: The object's dma-resv lock will protect i915_vma state and needs
+ *    to be held while binding/unbinding a vma in the async worker and while
+ *    updating dma-resv fence list of an object. Note that private BOs of a VM
+ *    will all share a dma-resv object.
+ *
+ *    The future system allocator support will use the HMM prescribed locking
+ *    instead.
+ *
+ * 3) Lock-C: Spinlock/s to protect some of the VM's lists like the list of
+ *    invalidated vmas (due to eviction and userptr invalidation) etc.
+ */
+
+struct i915_vma *
+i915_gem_vm_bind_lookup_vma(struct i915_address_space *vm, u64 va)
+{
+	struct i915_vma *vma, *temp;
+
+	assert_vm_bind_held(vm);
+
+	vma = i915_vm_bind_it_iter_first(&vm->va, va, va);
+	/* Working around compiler error, remove later */
+	if (vma)
+		temp = i915_vm_bind_it_iter_next(vma, va + vma->size, -1);
+	return vma;
+}
+
+void i915_gem_vm_bind_remove(struct i915_vma *vma, bool release_obj)
+{
+	assert_vm_bind_held(vma->vm);
+
+	if (!list_empty(&vma->vm_bind_link)) {
+		list_del_init(&vma->vm_bind_link);
+		i915_vm_bind_it_remove(vma, &vma->vm->va);
+
+		/* Release object */
+		if (release_obj)
+			i915_vma_put(vma);
+	}
+}
+
+int i915_gem_vm_unbind_obj(struct i915_address_space *vm,
+			   struct drm_i915_gem_vm_unbind *va)
+{
+	struct drm_i915_gem_object *obj;
+	struct i915_vma *vma;
+	int ret;
+
+	va->start = gen8_noncanonical_addr(va->start);
+	ret = i915_gem_vm_bind_lock_interruptible(vm);
+	if (ret)
+		return ret;
+
+	vma = i915_gem_vm_bind_lookup_vma(vm, va->start);
+	if (!vma) {
+		ret = -ENOENT;
+		goto out_unlock;
+	}
+
+	if (vma->size != va->length)
+		ret = -EINVAL;
+	else
+		i915_gem_vm_bind_remove(vma, false);
+
+out_unlock:
+	i915_gem_vm_bind_unlock(vm);
+	if (ret || !vma)
+		return ret;
+
+	/* Destroy vma and then release object */
+	obj = vma->obj;
+	ret = i915_gem_object_lock(obj, NULL);
+	if (ret)
+		return ret;
+
+	i915_vma_destroy(vma);
+	i915_gem_object_unlock(obj);
+	i915_gem_object_put(obj);
+
+	return 0;
+}
+
+static struct i915_vma *vm_bind_get_vma(struct i915_address_space *vm,
+					struct drm_i915_gem_object *obj,
+					struct drm_i915_gem_vm_bind *va)
+{
+	struct i915_ggtt_view view;
+	struct i915_vma *vma;
+
+	va->start = gen8_noncanonical_addr(va->start);
+	vma = i915_gem_vm_bind_lookup_vma(vm, va->start);
+	if (vma)
+		return ERR_PTR(-EEXIST);
+
+	view.type = I915_GGTT_VIEW_PARTIAL;
+	view.partial.offset = va->offset >> PAGE_SHIFT;
+	view.partial.size = va->length >> PAGE_SHIFT;
+	vma = i915_vma_instance(obj, vm, &view);
+	if (IS_ERR(vma))
+		return vma;
+
+	vma->start = va->start;
+	vma->last = va->start + va->length - 1;
+
+	return vma;
+}
+
+int i915_gem_vm_bind_obj(struct i915_address_space *vm,
+			 struct drm_i915_gem_vm_bind *va,
+			 struct drm_file *file)
+{
+	struct drm_i915_gem_object *obj;
+	struct i915_vma *vma = NULL;
+	struct i915_gem_ww_ctx ww;
+	u64 pin_flags;
+	int ret = 0;
+
+	if (!vm->vm_bind_mode)
+		return -EOPNOTSUPP;
+
+	obj = i915_gem_object_lookup(file, va->handle);
+	if (!obj)
+		return -ENOENT;
+
+	if (!va->length ||
+	    !IS_ALIGNED(va->offset | va->length,
+			i915_gem_object_max_page_size(obj->mm.placements,
+						      obj->mm.n_placements)) ||
+	    range_overflows_t(u64, va->offset, va->length, obj->base.size)) {
+		ret = -EINVAL;
+		goto put_obj;
+	}
+
+	ret = i915_gem_vm_bind_lock_interruptible(vm);
+	if (ret)
+		goto put_obj;
+
+	vma = vm_bind_get_vma(vm, obj, va);
+	if (IS_ERR(vma)) {
+		ret = PTR_ERR(vma);
+		goto unlock_vm;
+	}
+
+	i915_gem_ww_ctx_init(&ww, true);
+	pin_flags = va->start | PIN_OFFSET_FIXED | PIN_USER;
+retry:
+	ret = i915_gem_object_lock(vma->obj, &ww);
+	if (ret)
+		goto out_ww;
+
+	ret = i915_vma_pin_ww(vma, &ww, 0, 0, pin_flags);
+	if (ret)
+		goto out_ww;
+
+	/* Make it evictable */
+	__i915_vma_unpin(vma);
+
+	list_add_tail(&vma->vm_bind_link, &vm->vm_bound_list);
+	i915_vm_bind_it_insert(vma, &vm->va);
+
+	/* Hold object reference until vm_unbind */
+	i915_gem_object_get(vma->obj);
+out_ww:
+	if (ret == -EDEADLK) {
+		ret = i915_gem_ww_ctx_backoff(&ww);
+		if (!ret)
+			goto retry;
+	}
+
+	if (ret)
+		i915_vma_destroy(vma);
+
+	i915_gem_ww_ctx_fini(&ww);
+unlock_vm:
+	i915_gem_vm_bind_unlock(vm);
+put_obj:
+	i915_gem_object_put(obj);
+	return ret;
+}
diff --git a/drivers/gpu/drm/i915/gt/intel_gtt.c b/drivers/gpu/drm/i915/gt/intel_gtt.c
index b67831833c9a..135dc4a76724 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.c
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.c
@@ -176,6 +176,8 @@ int i915_vm_lock_objects(struct i915_address_space *vm,
 void i915_address_space_fini(struct i915_address_space *vm)
 {
 	drm_mm_takedown(&vm->mm);
+	GEM_BUG_ON(!RB_EMPTY_ROOT(&vm->va.rb_root));
+	mutex_destroy(&vm->vm_bind_lock);
 }
 
 /**
@@ -282,6 +284,11 @@ void i915_address_space_init(struct i915_address_space *vm, int subclass)
 
 	INIT_LIST_HEAD(&vm->bound_list);
 	INIT_LIST_HEAD(&vm->unbound_list);
+
+	vm->va = RB_ROOT_CACHED;
+	INIT_LIST_HEAD(&vm->vm_bind_list);
+	INIT_LIST_HEAD(&vm->vm_bound_list);
+	mutex_init(&vm->vm_bind_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 c812aa9708ae..d4a6ce65251d 100644
--- a/drivers/gpu/drm/i915/gt/intel_gtt.h
+++ b/drivers/gpu/drm/i915/gt/intel_gtt.h
@@ -259,6 +259,15 @@ struct i915_address_space {
 	 */
 	struct list_head unbound_list;
 
+	/**
+	 * List of VM_BIND objects.
+	 */
+	struct mutex vm_bind_lock;  /* Protects vm_bind lists */
+	struct list_head vm_bind_list;
+	struct list_head vm_bound_list;
+	/* va tree of persistent vmas */
+	struct rb_root_cached va;
+
 	/* Global GTT */
 	bool is_ggtt:1;
 
diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
index ccf990dfd99b..776ab7844f60 100644
--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -68,6 +68,7 @@
 #include "gem/i915_gem_ioctls.h"
 #include "gem/i915_gem_mman.h"
 #include "gem/i915_gem_pm.h"
+#include "gem/i915_gem_vm_bind.h"
 #include "gt/intel_gt.h"
 #include "gt/intel_gt_pm.h"
 #include "gt/intel_rc6.h"
@@ -1783,13 +1784,16 @@ static int i915_gem_vm_bind_ioctl(struct drm_device *dev, void *data,
 {
 	struct drm_i915_gem_vm_bind *args = data;
 	struct i915_address_space *vm;
+	int ret;
 
 	vm = i915_gem_vm_lookup(file->driver_priv, args->vm_id);
 	if (unlikely(!vm))
 		return -ENOENT;
 
+	ret = i915_gem_vm_bind_obj(vm, args, file);
+
 	i915_vm_put(vm);
-	return -EINVAL;
+	return ret;
 }
 
 static int i915_gem_vm_unbind_ioctl(struct drm_device *dev, void *data,
@@ -1797,13 +1801,16 @@ static int i915_gem_vm_unbind_ioctl(struct drm_device *dev, void *data,
 {
 	struct drm_i915_gem_vm_unbind *args = data;
 	struct i915_address_space *vm;
+	int ret;
 
 	vm = i915_gem_vm_lookup(file->driver_priv, args->vm_id);
 	if (unlikely(!vm))
 		return -ENOENT;
 
+	ret = i915_gem_vm_unbind_obj(vm, args);
+
 	i915_vm_put(vm);
-	return -EINVAL;
+	return ret;
 }
 
 static const struct drm_ioctl_desc i915_ioctls[] = {
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index ef3b04c7e153..23098c396565 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -29,6 +29,7 @@
 #include "display/intel_frontbuffer.h"
 #include "gem/i915_gem_lmem.h"
 #include "gem/i915_gem_tiling.h"
+#include "gem/i915_gem_vm_bind.h"
 #include "gt/intel_engine.h"
 #include "gt/intel_engine_heartbeat.h"
 #include "gt/intel_gt.h"
@@ -234,6 +235,7 @@ vma_create(struct drm_i915_gem_object *obj,
 	spin_unlock(&obj->vma.lock);
 	mutex_unlock(&vm->mutex);
 
+	INIT_LIST_HEAD(&vma->vm_bind_link);
 	return vma;
 
 err_unlock:
@@ -290,7 +292,6 @@ i915_vma_instance(struct drm_i915_gem_object *obj,
 {
 	struct i915_vma *vma;
 
-	GEM_BUG_ON(view && !i915_is_ggtt_or_dpt(vm));
 	GEM_BUG_ON(!kref_read(&vm->ref));
 
 	spin_lock(&obj->vma.lock);
@@ -1660,6 +1661,10 @@ static void release_references(struct i915_vma *vma, struct intel_gt *gt,
 
 	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);
+
 	spin_lock_irq(&gt->closed_lock);
 	__i915_vma_remove_closed(vma);
 	spin_unlock_irq(&gt->closed_lock);
diff --git a/drivers/gpu/drm/i915/i915_vma.h b/drivers/gpu/drm/i915/i915_vma.h
index 88ca0bd9c900..dcb49f79ff7e 100644
--- a/drivers/gpu/drm/i915/i915_vma.h
+++ b/drivers/gpu/drm/i915/i915_vma.h
@@ -164,8 +164,6 @@ i915_vma_compare(struct i915_vma *vma,
 {
 	ptrdiff_t cmp;
 
-	GEM_BUG_ON(view && !i915_is_ggtt_or_dpt(vm));
-
 	cmp = ptrdiff(vma->vm, vm);
 	if (cmp)
 		return cmp;
diff --git a/drivers/gpu/drm/i915/i915_vma_types.h b/drivers/gpu/drm/i915/i915_vma_types.h
index be6e028c3b57..b6d179bdbfa0 100644
--- a/drivers/gpu/drm/i915/i915_vma_types.h
+++ b/drivers/gpu/drm/i915/i915_vma_types.h
@@ -289,6 +289,14 @@ struct i915_vma {
 	/** This object's place on the active/inactive lists */
 	struct list_head vm_link;
 
+	struct list_head vm_bind_link; /* Link in persistent VMA list */
+
+	/** Interval tree structures for persistent vma */
+	struct rb_node rb;
+	u64 start;
+	u64 last;
+	u64 __subtree_last;
+
 	struct list_head obj_link; /* Link in the object's VMA list */
 	struct rb_node obj_node;
 	struct hlist_node obj_hash;