1 files changed, 233 insertions, 0 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
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;
+}