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authorNoralf Trønnes <noralf@tronnes.org>2018-11-10 17:56:46 +0300
committerNoralf Trønnes <noralf@tronnes.org>2018-11-20 16:57:25 +0300
commitb9068cde51eea189c2c3560a9a8ae83f7b213c9c (patch)
treea0fccbb4bbbdb067c68070e53d64844659b9f70e /drivers
parentb39b5394fabc79acbaafb26b777fd348c868bf7e (diff)
downloadlinux-b9068cde51eea189c2c3560a9a8ae83f7b213c9c.tar.xz
drm/cma-helper: Add DRM_GEM_CMA_VMAP_DRIVER_OPS
This adds functionality to the CMA helper which ensures that the kernel virtual address is set on the CMA GEM object also for imported buffers. The drivers have been audited to ensure that none set ->vaddr on imported buffers, making the conditional dma_buf_vunmap() call in drm_gem_cma_free_object() safe. Signed-off-by: Noralf Trønnes <noralf@tronnes.org> Acked-by: Christian König <christian.koenig@amd.com> Reviewed-by: Eric Anholt <eric@anholt.net> Link: https://patchwork.freedesktop.org/patch/msgid/20181110145647.17580-5-noralf@tronnes.org
Diffstat (limited to 'drivers')
-rw-r--r--drivers/gpu/drm/drm_gem_cma_helper.c86
1 files changed, 86 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
index 1d2ced882b66..cc26625b4b33 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -176,6 +176,7 @@ drm_gem_cma_create_with_handle(struct drm_file *file_priv,
*
* This function frees the backing memory of the CMA GEM object, cleans up the
* GEM object state and frees the memory used to store the object itself.
+ * If the buffer is imported and the virtual address is set, it is released.
* Drivers using the CMA helpers should set this as their
* &drm_driver.gem_free_object_unlocked callback.
*/
@@ -189,6 +190,8 @@ void drm_gem_cma_free_object(struct drm_gem_object *gem_obj)
dma_free_wc(gem_obj->dev->dev, cma_obj->base.size,
cma_obj->vaddr, cma_obj->paddr);
} else if (gem_obj->import_attach) {
+ if (cma_obj->vaddr)
+ dma_buf_vunmap(gem_obj->import_attach->dmabuf, cma_obj->vaddr);
drm_prime_gem_destroy(gem_obj, cma_obj->sgt);
}
@@ -575,3 +578,86 @@ void drm_gem_cma_prime_vunmap(struct drm_gem_object *obj, void *vaddr)
/* Nothing to do */
}
EXPORT_SYMBOL_GPL(drm_gem_cma_prime_vunmap);
+
+static const struct drm_gem_object_funcs drm_cma_gem_default_funcs = {
+ .free = drm_gem_cma_free_object,
+ .print_info = drm_gem_cma_print_info,
+ .get_sg_table = drm_gem_cma_prime_get_sg_table,
+ .vmap = drm_gem_cma_prime_vmap,
+ .vm_ops = &drm_gem_cma_vm_ops,
+};
+
+/**
+ * drm_cma_gem_create_object_default_funcs - Create a CMA GEM object with a
+ * default function table
+ * @dev: DRM device
+ * @size: Size of the object to allocate
+ *
+ * This sets the GEM object functions to the default CMA helper functions.
+ * This function can be used as the &drm_driver.gem_create_object callback.
+ *
+ * Returns:
+ * A pointer to a allocated GEM object or an error pointer on failure.
+ */
+struct drm_gem_object *
+drm_cma_gem_create_object_default_funcs(struct drm_device *dev, size_t size)
+{
+ struct drm_gem_cma_object *cma_obj;
+
+ cma_obj = kzalloc(sizeof(*cma_obj), GFP_KERNEL);
+ if (!cma_obj)
+ return NULL;
+
+ cma_obj->base.funcs = &drm_cma_gem_default_funcs;
+
+ return &cma_obj->base;
+}
+EXPORT_SYMBOL(drm_cma_gem_create_object_default_funcs);
+
+/**
+ * drm_gem_cma_prime_import_sg_table_vmap - PRIME import another driver's
+ * scatter/gather table and get the virtual address of the buffer
+ * @dev: DRM device
+ * @attach: DMA-BUF attachment
+ * @sgt: Scatter/gather table of pinned pages
+ *
+ * This function imports a scatter/gather table using
+ * drm_gem_cma_prime_import_sg_table() and uses dma_buf_vmap() to get the kernel
+ * virtual address. This ensures that a CMA GEM object always has its virtual
+ * address set. This address is released when the object is freed.
+ *
+ * This function can be used as the &drm_driver.gem_prime_import_sg_table
+ * callback. The DRM_GEM_CMA_VMAP_DRIVER_OPS() macro provides a shortcut to set
+ * the necessary DRM driver operations.
+ *
+ * Returns:
+ * A pointer to a newly created GEM object or an ERR_PTR-encoded negative
+ * error code on failure.
+ */
+struct drm_gem_object *
+drm_gem_cma_prime_import_sg_table_vmap(struct drm_device *dev,
+ struct dma_buf_attachment *attach,
+ struct sg_table *sgt)
+{
+ struct drm_gem_cma_object *cma_obj;
+ struct drm_gem_object *obj;
+ void *vaddr;
+
+ vaddr = dma_buf_vmap(attach->dmabuf);
+ if (!vaddr) {
+ DRM_ERROR("Failed to vmap PRIME buffer\n");
+ return ERR_PTR(-ENOMEM);
+ }
+
+ obj = drm_gem_cma_prime_import_sg_table(dev, attach, sgt);
+ if (IS_ERR(obj)) {
+ dma_buf_vunmap(attach->dmabuf, vaddr);
+ return obj;
+ }
+
+ cma_obj = to_drm_gem_cma_obj(obj);
+ cma_obj->vaddr = vaddr;
+
+ return obj;
+}
+EXPORT_SYMBOL(drm_gem_cma_prime_import_sg_table_vmap);