[PATCH v2 21/21] drm: Remove obsolete GEM and PRIME callbacks from struct drm_driver

Thomas Zimmermann
2020-09-15T23:01:21Z

Several GEM and PRIME callbacks have been deprecated in favor of
per-instance GEM object functions. Remove the callbacks as they are
now unused. The only exception is .gem_prime_mmap, which is still
in use by several drivers.

What is also gone is gem_vm_ops in struct drm_driver. All drivers now
use struct drm_gem_object_funcs.vm_ops instead.

While at it, the patch also improves error handling around calls
to .free and .get_sg_table callbacks.

v2:
* update related TODO item (Sam)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
Documentation/gpu/todo.rst | 7 +--
drivers/gpu/drm/drm_gem.c | 35 +++---------
drivers/gpu/drm/drm_gem_cma_helper.c | 6 +-
drivers/gpu/drm/drm_prime.c | 17 +++---
include/drm/drm_drv.h | 85 ++--------------------------
5 files changed, 25 insertions(+), 125 deletions(-)

diff --git a/Documentation/gpu/todo.rst b/Documentation/gpu/todo.rst
index b0ea17da8ff6..0fc6bc222392 100644
--- a/Documentation/gpu/todo.rst
+++ b/Documentation/gpu/todo.rst
@@ -289,11 +289,8 @@ struct drm_gem_object_funcs
---------------------------

GEM objects can now have a function table instead of having the callbacks on the
-DRM driver struct. This is now the preferred way and drivers can be moved over.
-
-We also need a 2nd version of the CMA define that doesn't require the
-vmapping to be present (different hook for prime importing). Plus this needs to
-be rolled out to all drivers using their own implementations, too.
+DRM driver struct. This is now the preferred way. Callbacks in drivers have been
+converted, except for struct drm_driver.gem_prime_mmap.

Level: Intermediate

diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 19d73868490e..96945bed8291 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -247,12 +247,9 @@ drm_gem_object_release_handle(int id, void *ptr, void *data)
{
struct drm_file *file_priv = data;
struct drm_gem_object *obj = ptr;
- struct drm_device *dev = obj->dev;

if (obj->funcs && obj->funcs->close)
obj->funcs->close(obj, file_priv);
- else if (dev->driver->gem_close_object)
- dev->driver->gem_close_object(obj, file_priv);

drm_gem_remove_prime_handles(obj, file_priv);
drm_vma_node_revoke(&obj->vma_node, file_priv);
@@ -407,10 +404,6 @@ drm_gem_handle_create_tail(struct drm_file *file_priv,
ret = obj->funcs->open(obj, file_priv);
if (ret)
goto err_revoke;
- } else if (dev->driver->gem_open_object) {
- ret = dev->driver->gem_open_object(obj, file_priv);
- if (ret)
- goto err_revoke;
}

*handlep = handle;
@@ -982,12 +975,11 @@ drm_gem_object_free(struct kref *kref)
{
struct drm_gem_object *obj =
container_of(kref, struct drm_gem_object, refcount);
- struct drm_device *dev = obj->dev;

- if (obj->funcs)
- obj->funcs->free(obj);
- else if (dev->driver->gem_free_object_unlocked)
- dev->driver->gem_free_object_unlocked(obj);
+ if (drm_WARN_ON_ONCE(obj->dev, !obj->funcs || !obj->funcs->free))
+ return;
+
+ obj->funcs->free(obj);
}
EXPORT_SYMBOL(drm_gem_object_free);

@@ -1049,9 +1041,9 @@ EXPORT_SYMBOL(drm_gem_vm_close);
* @obj_size: the object size to be mapped, in bytes
* @vma: VMA for the area to be mapped
*
- * Set up the VMA to prepare mapping of the GEM object using the gem_vm_ops
- * provided by the driver. Depending on their requirements, drivers can either
- * provide a fault handler in their gem_vm_ops (in which case any accesses to
+ * Set up the VMA to prepare mapping of the GEM object using the GEM object's
+ * vm_ops. Depending on their requirements, GEM objects can either
+ * provide a fault handler in their vm_ops (in which case any accesses to
* the object will be trapped, to perform migration, GTT binding, surface
* register allocation, or performance monitoring), or mmap the buffer memory
* synchronously after calling drm_gem_mmap_obj.
@@ -1065,12 +1057,11 @@ EXPORT_SYMBOL(drm_gem_vm_close);
* callers must verify access restrictions before calling this helper.
*
* Return 0 or success or -EINVAL if the object size is smaller than the VMA
- * size, or if no gem_vm_ops are provided.
+ * size, or if no vm_ops are provided.
*/
int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
struct vm_area_struct *vma)
{
- struct drm_device *dev = obj->dev;
int ret;

/* Check for valid size. */
@@ -1095,8 +1086,6 @@ int drm_gem_mmap_obj(struct drm_gem_object *obj, unsigned long obj_size,
} else {
if (obj->funcs && obj->funcs->vm_ops)
vma->vm_ops = obj->funcs->vm_ops;
- else if (dev->driver->gem_vm_ops)
- vma->vm_ops = dev->driver->gem_vm_ops;
else {
drm_gem_object_put(obj);
return -EINVAL;
@@ -1206,8 +1195,6 @@ int drm_gem_pin(struct drm_gem_object *obj)
{
if (obj->funcs && obj->funcs->pin)
return obj->funcs->pin(obj);
- else if (obj->dev->driver->gem_prime_pin)
- return obj->dev->driver->gem_prime_pin(obj);
else
return 0;
}
@@ -1216,8 +1203,6 @@ void drm_gem_unpin(struct drm_gem_object *obj)
{
if (obj->funcs && obj->funcs->unpin)
obj->funcs->unpin(obj);
- else if (obj->dev->driver->gem_prime_unpin)
- obj->dev->driver->gem_prime_unpin(obj);
}

void *drm_gem_vmap(struct drm_gem_object *obj)
@@ -1226,8 +1211,6 @@ void *drm_gem_vmap(struct drm_gem_object *obj)

if (obj->funcs && obj->funcs->vmap)
vaddr = obj->funcs->vmap(obj);
- else if (obj->dev->driver->gem_prime_vmap)
- vaddr = obj->dev->driver->gem_prime_vmap(obj);
else
vaddr = ERR_PTR(-EOPNOTSUPP);

@@ -1244,8 +1227,6 @@ void drm_gem_vunmap(struct drm_gem_object *obj, void *vaddr)

if (obj->funcs && obj->funcs->vunmap)
obj->funcs->vunmap(obj, vaddr);
- else if (obj->dev->driver->gem_prime_vunmap)
- obj->dev->driver->gem_prime_vunmap(obj, vaddr);
}

/**
diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
index 822edeadbab3..209202257cc2 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -419,7 +419,7 @@ EXPORT_SYMBOL(drm_gem_cma_print_info);
*
* This function exports a scatter/gather table suitable for PRIME usage by
* calling the standard DMA mapping API. Drivers using the CMA helpers should
- * set this as their &drm_driver.gem_prime_get_sg_table callback.
+ * set this as their &drm_gem_object_funcs.get_sg_table callback.
*
* Returns:
* A pointer to the scatter/gather table of pinned pages or NULL on failure.
@@ -542,7 +542,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_mmap);
* virtual address space. Since the CMA buffers are already mapped into the
* kernel virtual address space this simply returns the cached virtual
* address. Drivers using the CMA helpers should set this as their DRM
- * driver's &drm_driver.gem_prime_vmap callback.
+ * driver's &drm_gem_object_funcs.vmap callback.
*
* Returns:
* The kernel virtual address of the CMA GEM object's backing store.
@@ -564,7 +564,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vmap);
* This function removes a buffer exported via DRM PRIME from the kernel's
* virtual address space. This is a no-op because CMA buffers cannot be
* unmapped from kernel space. Drivers using the CMA helpers should set this
- * as their &drm_driver.gem_prime_vunmap callback.
+ * as their &drm_gem_object_funcs.vunmap callback.
*/
void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
{
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 8a6a3c99b7d8..1cffb004d3c8 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -386,10 +386,6 @@ static struct dma_buf *export_and_register_object(struct drm_device *dev,

if (obj->funcs && obj->funcs->export)
dmabuf = obj->funcs->export(obj, flags);
- else if (dev->driver->gem_prime_export)
- dmabuf = dev->driver->gem_prime_export(obj, flags);
- else
- dmabuf = drm_gem_prime_export(obj, flags);
if (IS_ERR(dmabuf)) {
/* normally the created dma-buf takes ownership of the ref,
* but if that fails then drop the ref
@@ -419,7 +415,7 @@ static struct dma_buf *export_and_register_object(struct drm_device *dev,
* This is the PRIME export function which must be used mandatorily by GEM
* drivers to ensure correct lifetime management of the underlying GEM object.
* The actual exporting from GEM object to a dma-buf is done through the
- * &drm_driver.gem_prime_export driver callback.
+ * &drm_gem_object_funcs.export callback.
*/
int drm_gem_prime_handle_to_fd(struct drm_device *dev,
struct drm_file *file_priv, uint32_t handle,
@@ -616,15 +612,18 @@ struct sg_table *drm_gem_map_dma_buf(struct dma_buf_attachment *attach,
enum dma_data_direction dir)
{
struct drm_gem_object *obj = attach->dmabuf->priv;
- struct sg_table *sgt;
+ struct sg_table *sgt = NULL;

if (WARN_ON(dir == DMA_NONE))
return ERR_PTR(-EINVAL);

- if (obj->funcs)
+ if (obj->funcs && obj->funcs->get_sg_table)
sgt = obj->funcs->get_sg_table(obj);
- else
- sgt = obj->dev->driver->gem_prime_get_sg_table(obj);
+
+ if (!sgt)
+ return ERR_PTR(-EINVAL);
+ else if (IS_ERR(sgt))
+ return sgt;

if (!dma_map_sg_attrs(attach->dev, sgt->sgl, sgt->nents, dir,
DMA_ATTR_SKIP_CPU_SYNC)) {
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index 9b11a2f0babc..240b0eab8018 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -36,10 +36,12 @@ struct drm_file;
struct drm_gem_object;
struct drm_master;
struct drm_minor;
+struct dma_buf;
struct dma_buf_attachment;
struct drm_display_mode;
struct drm_mode_create_dumb;
struct drm_printer;
+struct sg_table;

/**
* enum drm_driver_feature - feature flags
@@ -326,32 +328,6 @@ struct drm_driver {
*/
void (*debugfs_init)(struct drm_minor *minor);

- /**
- * @gem_free_object_unlocked: deconstructor for drm_gem_objects
- *
- * This is deprecated and should not be used by new drivers. Use
- * &drm_gem_object_funcs.free instead.
- */
- void (*gem_free_object_unlocked) (struct drm_gem_object *obj);
-
- /**
- * @gem_open_object:
- *
- * This callback is deprecated in favour of &drm_gem_object_funcs.open.
- *
- * Driver hook called upon gem handle creation
- */
- int (*gem_open_object) (struct drm_gem_object *, struct drm_file *);
-
- /**
- * @gem_close_object:
- *
- * This callback is deprecated in favour of &drm_gem_object_funcs.close.
- *
- * Driver hook called upon gem handle release
- */
- void (*gem_close_object) (struct drm_gem_object *, struct drm_file *);
-
/**
* @gem_create_object: constructor for gem objects
*
@@ -360,6 +336,7 @@ struct drm_driver {
*/
struct drm_gem_object *(*gem_create_object)(struct drm_device *dev,
size_t size);
+
/**
* @prime_handle_to_fd:
*
@@ -382,14 +359,7 @@ struct drm_driver {
*/
int (*prime_fd_to_handle)(struct drm_device *dev, struct drm_file *file_priv,
int prime_fd, uint32_t *handle);
- /**
- * @gem_prime_export:
- *
- * Export hook for GEM drivers. Deprecated in favour of
- * &drm_gem_object_funcs.export.
- */
- struct dma_buf * (*gem_prime_export)(struct drm_gem_object *obj,
- int flags);
+
/**
* @gem_prime_import:
*
@@ -399,29 +369,6 @@ struct drm_driver {
*/
struct drm_gem_object * (*gem_prime_import)(struct drm_device *dev,
struct dma_buf *dma_buf);
-
- /**
- * @gem_prime_pin:
- *
- * Deprecated hook in favour of &drm_gem_object_funcs.pin.
- */
- int (*gem_prime_pin)(struct drm_gem_object *obj);
-
- /**
- * @gem_prime_unpin:
- *
- * Deprecated hook in favour of &drm_gem_object_funcs.unpin.
- */
- void (*gem_prime_unpin)(struct drm_gem_object *obj);
-
-
- /**
- * @gem_prime_get_sg_table:
- *
- * Deprecated hook in favour of &drm_gem_object_funcs.get_sg_table.
- */
- struct sg_table *(*gem_prime_get_sg_table)(struct drm_gem_object *obj);
-
/**
* @gem_prime_import_sg_table:
*
@@ -432,22 +379,6 @@ struct drm_driver {
struct drm_device *dev,
struct dma_buf_attachment *attach,
struct sg_table *sgt);
- /**
- * @gem_prime_vmap:
- *
- * Deprecated vmap hook for GEM drivers. Please use
- * &drm_gem_object_funcs.vmap instead.
- */
- void *(*gem_prime_vmap)(struct drm_gem_object *obj);
-
- /**
- * @gem_prime_vunmap:
- *
- * Deprecated vunmap hook for GEM drivers. Please use
- * &drm_gem_object_funcs.vunmap instead.
- */
- void (*gem_prime_vunmap)(struct drm_gem_object *obj, void *vaddr);
-
/**
* @gem_prime_mmap:
*
@@ -522,14 +453,6 @@ struct drm_driver {
struct drm_device *dev,
uint32_t handle);

- /**
- * @gem_vm_ops: Driver private ops for this object
- *
- * For GEM drivers this is deprecated in favour of
- * &drm_gem_object_funcs.vm_ops.
- */
- const struct vm_operations_struct *gem_vm_ops;
-
/** @major: driver major number */
int major;
/** @minor: driver minor number */
--
2.28.0