Have i915 replace the core drm_gem_mmap implementation to overcome its
limitation in having only a single mmap offset node per gem object.
The change allows us to have multiple mmap offsets per object. This
enables a mmapping instance to use unique fault-handlers per user vma.
This enables us to store extra data within vma->vm_private_data and assign
the pagefault ops for each mmap instance allowing objects to use multiple
fault handlers depending on its backing storage.
Signed-off-by: Abdiel Janulgue <abdiel.janulgue@xxxxxxxxxxxxxxx>
Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Cc: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/gem/i915_gem_mman.c | 193 ++++++++++++++++--
drivers/gpu/drm/i915/gem/i915_gem_object.c | 19 ++
drivers/gpu/drm/i915/gem/i915_gem_object.h | 7 +-
.../gpu/drm/i915/gem/i915_gem_object_types.h | 18 ++
.../drm/i915/gem/selftests/i915_gem_mman.c | 12 +-
drivers/gpu/drm/i915/gt/intel_reset.c | 11 +-
drivers/gpu/drm/i915/i915_drv.c | 9 +-
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_vma.c | 20 +-
9 files changed, 254 insertions(+), 36 deletions(-)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
index 595539a09e38..fb7e39f115d7 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_mman.c
@@ -218,7 +218,8 @@ vm_fault_t i915_gem_fault(struct vm_fault *vmf)
{
#define MIN_CHUNK_PAGES (SZ_1M >> PAGE_SHIFT)
struct vm_area_struct *area = vmf->vma;
- struct drm_i915_gem_object *obj = to_intel_bo(area->vm_private_data);
+ struct i915_mmap_offset *priv = area->vm_private_data;
+ struct drm_i915_gem_object *obj = priv->obj;
struct drm_device *dev = obj->base.dev;
struct drm_i915_private *i915 = to_i915(dev);
struct intel_runtime_pm *rpm = &i915->runtime_pm;
@@ -372,13 +373,20 @@ vm_fault_t i915_gem_fault(struct vm_fault *vmf)
void __i915_gem_object_release_mmap(struct drm_i915_gem_object *obj)
{
struct i915_vma *vma;
+ struct i915_mmap_offset *mmo;
GEM_BUG_ON(!obj->userfault_count);
obj->userfault_count = 0;
list_del(&obj->userfault_link);
- drm_vma_node_unmap(&obj->base.vma_node,
- obj->base.dev->anon_inode->i_mapping);
+
+ mutex_lock(&obj->mmo_lock);
+ list_for_each_entry(mmo, &obj->mmap_offsets, offset) {
+ if (mmo->mmap_type == I915_MMAP_TYPE_GTT)
+ drm_vma_node_unmap(&mmo->vma_node,
+ obj->base.dev->anon_inode->i_mapping);
+ }
+ mutex_unlock(&obj->mmo_lock);
for_each_ggtt_vma(vma, obj)
i915_vma_unset_userfault(vma);
@@ -433,14 +441,33 @@ void i915_gem_object_release_mmap(struct drm_i915_gem_object *obj)
intel_runtime_pm_put(&i915->runtime_pm, wakeref);
}
-static int create_mmap_offset(struct drm_i915_gem_object *obj)
+static void init_mmap_offset(struct drm_i915_gem_object *obj,
+ struct i915_mmap_offset *mmo)
+{
+ mutex_lock(&obj->mmo_lock);
+ kref_init(&mmo->ref);
+ list_add(&mmo->offset, &obj->mmap_offsets);
+ mutex_unlock(&obj->mmo_lock);
+
+ mmo->obj = obj;
+}
+
+static int create_mmap_offset(struct drm_i915_gem_object *obj,
+ struct i915_mmap_offset *mmo)
{
struct drm_i915_private *i915 = to_i915(obj->base.dev);
+ struct drm_device *dev = obj->base.dev;
int err;
- err = drm_gem_create_mmap_offset(&obj->base);
- if (likely(!err))
+ drm_vma_node_reset(&mmo->vma_node);
+ if (mmo->file)
+ drm_vma_node_allow(&mmo->vma_node, mmo->file);
+ err = drm_vma_offset_add(dev->vma_offset_manager, &mmo->vma_node,
+ obj->base.size / PAGE_SIZE);
+ if (likely(!err)) {
+ init_mmap_offset(obj, mmo);
return 0;
+ }
/* Attempt to reap some mmap space from dead objects */
do {
@@ -451,32 +478,48 @@ static int create_mmap_offset(struct drm_i915_gem_object *obj)
break;
i915_gem_drain_freed_objects(i915);
- err = drm_gem_create_mmap_offset(&obj->base);
- if (!err)
+ err = drm_vma_offset_add(dev->vma_offset_manager, &mmo->vma_node,
+ obj->base.size / PAGE_SIZE);
+ if (!err) {
+ init_mmap_offset(obj, mmo);
break;
+ }
} while (flush_delayed_work(&i915->gem.retire_work));
return err;
}
-int
-i915_gem_mmap_gtt(struct drm_file *file,
- struct drm_device *dev,
- u32 handle,
- u64 *offset)
+static int
+__assign_gem_object_mmap_data(struct drm_file *file,
+ u32 handle,
+ enum i915_mmap_type mmap_type,
+ u64 *offset)
{
struct drm_i915_gem_object *obj;
+ struct i915_mmap_offset *mmo;
int ret;
obj = i915_gem_object_lookup(file, handle);
if (!obj)
return -ENOENT;
- ret = create_mmap_offset(obj);
- if (ret == 0)
- *offset = drm_vma_node_offset_addr(&obj->base.vma_node);
+ mmo = kzalloc(sizeof(*mmo), GFP_KERNEL);
+ if (!mmo) {
+ ret = -ENOMEM;
+ goto err;
+ }
+
+ mmo->file = file;
+ ret = create_mmap_offset(obj, mmo);
+ if (ret) {
+ kfree(mmo);
+ goto err;
+ }
+ mmo->mmap_type = mmap_type;
+ *offset = drm_vma_node_offset_addr(&mmo->vma_node);
+err:
i915_gem_object_put(obj);
return ret;
}
@@ -500,9 +543,123 @@ int
i915_gem_mmap_gtt_ioctl(struct drm_device *dev, void *data,
struct drm_file *file)
{
- struct drm_i915_gem_mmap_gtt *args = data;
+ struct drm_i915_gem_mmap_offset *args = data;
+
+ return __assign_gem_object_mmap_data(file, args->handle,
+ I915_MMAP_TYPE_GTT,
+ &args->offset);
+}
+
+void i915_mmap_offset_object_release(struct kref *ref)
+{
+ struct i915_mmap_offset *mmo = container_of(ref,
+ struct i915_mmap_offset,
+ ref);
+ struct drm_i915_gem_object *obj = mmo->obj;
+ struct drm_device *dev = obj->base.dev;
+
+ lockdep_assert_held(&obj->mmo_lock);
+
+ if (mmo->file)
+ drm_vma_node_revoke(&mmo->vma_node, mmo->file);
+ drm_vma_offset_remove(dev->vma_offset_manager, &mmo->vma_node);
+ list_del(&mmo->offset);
- return i915_gem_mmap_gtt(file, dev, args->handle, &args->offset);
+ kfree(mmo);
+}
+
+static void i915_gem_vm_open(struct vm_area_struct *vma)
+{
+ struct i915_mmap_offset *priv = vma->vm_private_data;
+ struct drm_i915_gem_object *obj = priv->obj;
+
+ i915_gem_object_get(obj);
+ kref_get(&priv->ref);
+}
+
+static void i915_gem_vm_close(struct vm_area_struct *vma)
+{
+ struct i915_mmap_offset *priv = vma->vm_private_data;
+ struct drm_i915_gem_object *obj = priv->obj;
+
+ mutex_lock(&obj->mmo_lock);
+ kref_put(&priv->ref, i915_mmap_offset_object_release);
+ mutex_unlock(&obj->mmo_lock);
+
+ i915_gem_object_put(obj);
+}
+
+static const struct vm_operations_struct i915_gem_gtt_vm_ops = {
+ .fault = i915_gem_fault,
+ .open = i915_gem_vm_open,
+ .close = i915_gem_vm_close,
+};
+
+/* This overcomes the limitation in drm_gem_mmap's assignment of a
+ * drm_gem_object as the vma->vm_private_data. Since we need to
+ * be able to resolve multiple mmap offsets which could be tied
+ * to a single gem object.
+ */
+int i915_gem_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ struct drm_vma_offset_node *node;
+ struct drm_file *priv = filp->private_data;
+ struct drm_device *dev = priv->minor->dev;
+ struct i915_mmap_offset *mmo = NULL;
+ struct drm_gem_object *obj = NULL;
+
+ if (drm_dev_is_unplugged(dev))
+ return -ENODEV;
+
+ drm_vma_offset_lock_lookup(dev->vma_offset_manager);
+ node = drm_vma_offset_exact_lookup_locked(dev->vma_offset_manager,
+ vma->vm_pgoff,
+ vma_pages(vma));
+ if (likely(node)) {
+ mmo = container_of(node, struct i915_mmap_offset,
+ vma_node);
+ /*
+ * Skip 0-refcnted objects as it is in the process of being
+ * destroyed and will be invalid when the vma manager lock
+ * is released.
+ */
+ obj = &mmo->obj->base;
+ if (!kref_get_unless_zero(&obj->refcount))
+ obj = NULL;
+ }
+ drm_vma_offset_unlock_lookup(dev->vma_offset_manager);
+
+ if (!obj)
+ return -EINVAL;
+
+ if (!drm_vma_node_is_allowed(node, priv)) {
+ drm_gem_object_put_unlocked(obj);
+ return -EACCES;
+ }
+
+ if (to_intel_bo(obj)->readonly) {
+ if (vma->vm_flags & VM_WRITE) {
+ drm_gem_object_put_unlocked(obj);
+ return -EINVAL;
+ }
+
+ vma->vm_flags &= ~VM_MAYWRITE;
+ }
+
+ vma->vm_flags |= VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
+ vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma->vm_flags));
+ vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
+ vma->vm_private_data = mmo;
+
+ vma->vm_ops = &i915_gem_gtt_vm_ops;
+
+ /*
+ * Take a ref for our mmap_offset object. The reference is cleaned
+ * up when the vma is closed.
+ */
+ kref_get(&mmo->ref);
+
+ return 0;
}
#if IS_ENABLED(CONFIG_DRM_I915_SELFTEST)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.c b/drivers/gpu/drm/i915/gem/i915_gem_object.c
index d7855dc5a5c5..eb3d7f3528f3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.c
@@ -58,6 +58,9 @@ void i915_gem_object_init(struct drm_i915_gem_object *obj,
INIT_LIST_HEAD(&obj->lut_list);
+ mutex_init(&obj->mmo_lock);
+ INIT_LIST_HEAD(&obj->mmap_offsets);
+
init_rcu_head(&obj->rcu);
obj->ops = ops;
@@ -94,6 +97,7 @@ void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file)
struct drm_i915_gem_object *obj = to_intel_bo(gem);
struct drm_i915_file_private *fpriv = file->driver_priv;
struct i915_lut_handle *lut, *ln;
+ struct i915_mmap_offset *mmo, *on;
LIST_HEAD(close);
i915_gem_object_lock(obj);
@@ -108,6 +112,13 @@ void i915_gem_close_object(struct drm_gem_object *gem, struct drm_file *file)
}
i915_gem_object_unlock(obj);
+ mutex_lock(&obj->mmo_lock);
+ list_for_each_entry_safe(mmo, on, &obj->mmap_offsets, offset) {
+ if (mmo->file == file)
+ kref_put(&mmo->ref, i915_mmap_offset_object_release);
+ }
+ mutex_unlock(&obj->mmo_lock);
+
list_for_each_entry_safe(lut, ln, &close, obj_link) {
struct i915_gem_context *ctx = lut->ctx;
struct i915_vma *vma;
@@ -156,6 +167,7 @@ static void __i915_gem_free_objects(struct drm_i915_private *i915,
wakeref = intel_runtime_pm_get(&i915->runtime_pm);
llist_for_each_entry_safe(obj, on, freed, freed) {
struct i915_vma *vma, *vn;
+ struct i915_mmap_offset *mmo, *on;
trace_i915_gem_object_destroy(obj);
@@ -169,6 +181,13 @@ static void __i915_gem_free_objects(struct drm_i915_private *i915,
GEM_BUG_ON(!list_empty(&obj->vma.list));
GEM_BUG_ON(!RB_EMPTY_ROOT(&obj->vma.tree));
+ i915_gem_object_release_mmap(obj);
+
+ mutex_lock(&obj->mmo_lock);
+ list_for_each_entry_safe(mmo, on, &obj->mmap_offsets, offset)
+ kref_put(&mmo->ref, i915_mmap_offset_object_release);
+ mutex_unlock(&obj->mmo_lock);
+
mutex_unlock(&i915->drm.struct_mutex);
GEM_BUG_ON(atomic_read(&obj->bind_count));
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index 5efb9936e05b..d667ed8bb0a6 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -125,13 +125,13 @@ void i915_gem_object_unlock_fence(struct drm_i915_gem_object *obj,
static inline void
i915_gem_object_set_readonly(struct drm_i915_gem_object *obj)
{
- obj->base.vma_node.readonly = true;
+ obj->readonly = true;
}
static inline bool
i915_gem_object_is_readonly(const struct drm_i915_gem_object *obj)
{
- return obj->base.vma_node.readonly;
+ return obj->readonly;
}
static inline bool
@@ -423,6 +423,9 @@ int i915_gem_object_wait(struct drm_i915_gem_object *obj,
int i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
unsigned int flags,
const struct i915_sched_attr *attr);
+
+void i915_mmap_offset_object_release(struct kref *ref);
+
#define I915_PRIORITY_DISPLAY I915_USER_PRIORITY(I915_PRIORITY_MAX)
#endif
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
index ede0eb4218a8..d74ddb479318 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object_types.h
@@ -60,6 +60,19 @@ struct drm_i915_gem_object_ops {
void (*release)(struct drm_i915_gem_object *obj);
};
+enum i915_mmap_type {
+ I915_MMAP_TYPE_GTT = 0,
+};
+
+struct i915_mmap_offset {
+ struct drm_vma_offset_node vma_node;
+ struct drm_i915_gem_object *obj;
+ struct drm_file *file;
+ enum i915_mmap_type mmap_type;
+ struct kref ref;
+ struct list_head offset;
+};
+
struct drm_i915_gem_object {
struct drm_gem_object base;
@@ -115,6 +128,11 @@ struct drm_i915_gem_object {
unsigned int userfault_count;
struct list_head userfault_link;
+ /* Protects access to mmap offsets */
+ struct mutex mmo_lock;
+ struct list_head mmap_offsets;
+ bool readonly:1;
+
I915_SELFTEST_DECLARE(struct list_head st_link);
/*
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
index 1d27babff0ce..a7513421b1db 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_mman.c
@@ -371,15 +371,20 @@ static bool assert_mmap_offset(struct drm_i915_private *i915,
int expected)
{
struct drm_i915_gem_object *obj;
+ /* refcounted in create_mmap_offset */
+ struct i915_mmap_offset *mmo = kzalloc(sizeof(*mmo), GFP_KERNEL);
int err;
obj = i915_gem_object_create_internal(i915, size);
if (IS_ERR(obj))
return PTR_ERR(obj);
- err = create_mmap_offset(obj);
+ err = create_mmap_offset(obj, mmo);
+ if (err)
+ kfree(mmo);
i915_gem_object_put(obj);
+
return err == expected;
}
@@ -422,6 +427,8 @@ static int igt_mmap_offset_exhaustion(void *arg)
struct drm_mm *mm = &i915->drm.vma_offset_manager->vm_addr_space_mm;
struct drm_i915_gem_object *obj;
struct drm_mm_node resv, *hole;
+ /* refcounted in create_mmap_offset */
+ struct i915_mmap_offset *mmo = kzalloc(sizeof(*mmo), GFP_KERNEL);
u64 hole_start, hole_end;
int loop, err;
@@ -465,9 +472,10 @@ static int igt_mmap_offset_exhaustion(void *arg)
goto out;
}
- err = create_mmap_offset(obj);
+ err = create_mmap_offset(obj, mmo);
if (err) {
pr_err("Unable to insert object into reclaimed hole\n");
+ kfree(mmo);
goto err_obj;
}
diff --git a/drivers/gpu/drm/i915/gt/intel_reset.c b/drivers/gpu/drm/i915/gt/intel_reset.c
index b9d84d52e986..7b82ef888b96 100644
--- a/drivers/gpu/drm/i915/gt/intel_reset.c
+++ b/drivers/gpu/drm/i915/gt/intel_reset.c
@@ -628,6 +628,7 @@ static void revoke_mmaps(struct intel_gt *gt)
for (i = 0; i < gt->ggtt->num_fences; i++) {
struct drm_vma_offset_node *node;
+ struct i915_mmap_offset *mmo;
struct i915_vma *vma;
u64 vma_offset;
@@ -641,10 +642,18 @@ static void revoke_mmaps(struct intel_gt *gt)
GEM_BUG_ON(vma->fence != >->ggtt->fence_regs[i]);
node = &vma->obj->base.vma_node;
vma_offset = vma->ggtt_view.partial.offset << PAGE_SHIFT;
- unmap_mapping_range(gt->i915->drm.anon_inode->i_mapping,
+
+ list_for_each_entry(mmo, &vma->obj->mmap_offsets, offset) {
+ node = &mmo->vma_node;
+ if (!drm_mm_node_allocated(&node->vm_node) ||
+ mmo->mmap_type != I915_MMAP_TYPE_GTT)
+ continue;
+
+ unmap_mapping_range(gt->i915->drm.anon_inode->i_mapping,
drm_vma_node_offset_addr(node) + vma_offset,
vma->size,
1);
+ }
}
}
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 1c4576a4a5e9..bdd597200984 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -2722,18 +2722,12 @@ const struct dev_pm_ops i915_pm_ops = {
.runtime_resume = intel_runtime_resume,
};
-static const struct vm_operations_struct i915_gem_vm_ops = {
- .fault = i915_gem_fault,
- .open = drm_gem_vm_open,
- .close = drm_gem_vm_close,
-};
-
static const struct file_operations i915_driver_fops = {
.owner = THIS_MODULE,
.open = drm_open,
.release = drm_release,
.unlocked_ioctl = drm_ioctl,
- .mmap = drm_gem_mmap,
+ .mmap = i915_gem_mmap,
.poll = drm_poll,
.read = drm_read,
.compat_ioctl = i915_compat_ioctl,
@@ -2822,7 +2816,6 @@ static struct drm_driver driver = {
.gem_close_object = i915_gem_close_object,
.gem_free_object_unlocked = i915_gem_free_object,
- .gem_vm_ops = &i915_gem_vm_ops,
.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index b42651a387d9..bf2927e88e14 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -2327,6 +2327,7 @@ int i915_gem_wait_for_idle(struct drm_i915_private *dev_priv,
void i915_gem_suspend(struct drm_i915_private *dev_priv);
void i915_gem_suspend_late(struct drm_i915_private *dev_priv);
void i915_gem_resume(struct drm_i915_private *dev_priv);
+int i915_gem_mmap(struct file *filp, struct vm_area_struct *vma);
vm_fault_t i915_gem_fault(struct vm_fault *vmf);
int i915_gem_open(struct drm_i915_private *i915, struct drm_file *file);
diff --git a/drivers/gpu/drm/i915/i915_vma.c b/drivers/gpu/drm/i915/i915_vma.c
index e0e677b2a3a9..677323644319 100644
--- a/drivers/gpu/drm/i915/i915_vma.c
+++ b/drivers/gpu/drm/i915/i915_vma.c
@@ -861,7 +861,8 @@ static void __i915_vma_iounmap(struct i915_vma *vma)
void i915_vma_revoke_mmap(struct i915_vma *vma)
{
- struct drm_vma_offset_node *node = &vma->obj->base.vma_node;
+ struct drm_vma_offset_node *node;
+ struct i915_mmap_offset *mmo;
u64 vma_offset;
lockdep_assert_held(&vma->vm->mutex);
@@ -873,10 +874,19 @@ void i915_vma_revoke_mmap(struct i915_vma *vma)
GEM_BUG_ON(!vma->obj->userfault_count);
vma_offset = vma->ggtt_view.partial.offset << PAGE_SHIFT;
- unmap_mapping_range(vma->vm->i915->drm.anon_inode->i_mapping,
- drm_vma_node_offset_addr(node) + vma_offset,
- vma->size,
- 1);
+
+ list_for_each_entry(mmo, &vma->obj->mmap_offsets, offset) {
+ node = &mmo->vma_node;
+ /* Only gtt-mmaps for this vma should be unmapped */
+ if (!drm_mm_node_allocated(&node->vm_node) ||
+ mmo->mmap_type != I915_MMAP_TYPE_GTT)
+ continue;
+
+ unmap_mapping_range(vma->vm->i915->drm.anon_inode->i_mapping,
+ drm_vma_node_offset_addr(node) + vma_offset,
+ vma->size,
+ 1);
+ }
i915_vma_unset_userfault(vma);
if (!--vma->obj->userfault_count)
--
2.23.0
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