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

Am 15.09.20 um 16:59 schrieb Thomas Zimmermann:

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);
  

Oops, these two lines were not supposed to be removed. They'll return in v3 of the patchset. That will also fix the error report that was posted by the CI. [1]

Best regards Thomas

[1] https://lore.kernel.org/intel-gfx/160018797587.30601.1382075328491651866@eme...

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 */