[PATCH v2 2/5] drm: Add and export function drm_gem_cma_dumb_create_noncoherent

Paul Cercueil
2021-03-07T20:30:09Z

This function can be used by drivers to create dumb buffers with
non-coherent backing memory.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
drivers/gpu/drm/drm_gem_cma_helper.c | 37 +++++++++++++++++++++++++---
include/drm/drm_gem_cma_helper.h | 5 ++++
2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
index 917b092b23c2..d100c5f9c140 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -181,6 +181,7 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_create);
* @drm: DRM device
* @size: size of the object to allocate
* @handle: return location for the GEM handle
+ * @noncoherent: allocate object with non-coherent cache attribute
*
* This function creates a CMA GEM object, allocating a physically contiguous
* chunk of memory as backing store. The GEM object is then added to the list
@@ -193,13 +194,13 @@ EXPORT_SYMBOL_GPL(drm_gem_cma_create);
static struct drm_gem_cma_object *
drm_gem_cma_create_with_handle(struct drm_file *file_priv,
struct drm_device *drm, size_t size,
- uint32_t *handle)
+ uint32_t *handle, bool noncoherent)
{
struct drm_gem_cma_object *cma_obj;
struct drm_gem_object *gem_obj;
int ret;

- cma_obj = drm_gem_cma_create(drm, size);
+ cma_obj = drm_gem_cma_create_with_cache_param(drm, size, noncoherent);
if (IS_ERR(cma_obj))
return cma_obj;

@@ -276,7 +277,7 @@ int drm_gem_cma_dumb_create_internal(struct drm_file *file_priv,
args->size = args->pitch * args->height;

cma_obj = drm_gem_cma_create_with_handle(file_priv, drm, args->size,
- &args->handle);
+ &args->handle, false);
return PTR_ERR_OR_ZERO(cma_obj);
}
EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create_internal);
@@ -309,11 +310,39 @@ int drm_gem_cma_dumb_create(struct drm_file *file_priv,
args->size = args->pitch * args->height;

cma_obj = drm_gem_cma_create_with_handle(file_priv, drm, args->size,
- &args->handle);
+ &args->handle, false);
return PTR_ERR_OR_ZERO(cma_obj);
}
EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create);

+/**
+ * drm_gem_cma_dumb_create_noncoherent - create a dumb buffer object with
+ * non-coherent cache attribute
+ * @file_priv: DRM file-private structure to create the dumb buffer for
+ * @drm: DRM device
+ * @args: IOCTL data
+ *
+ * Same as drm_gem_cma_dumb_create, but the dumb buffer object created has
+ * the non-coherent cache attribute set.
+ *
+ * Returns:
+ * 0 on success or a negative error code on failure.
+ */
+int drm_gem_cma_dumb_create_noncoherent(struct drm_file *file_priv,
+ struct drm_device *drm,
+ struct drm_mode_create_dumb *args)
+{
+ struct drm_gem_cma_object *cma_obj;
+
+ args->pitch = DIV_ROUND_UP(args->width * args->bpp, 8);
+ args->size = args->pitch * args->height;
+
+ cma_obj = drm_gem_cma_create_with_handle(file_priv, drm, args->size,
+ &args->handle, true);
+ return PTR_ERR_OR_ZERO(cma_obj);
+}
+EXPORT_SYMBOL_GPL(drm_gem_cma_dumb_create_noncoherent);
+
const struct vm_operations_struct drm_gem_cma_vm_ops = {
.open = drm_gem_vm_open,
.close = drm_gem_vm_close,
diff --git a/include/drm/drm_gem_cma_helper.h b/include/drm/drm_gem_cma_helper.h
index 360771f5f485..6b44e7492a63 100644
--- a/include/drm/drm_gem_cma_helper.h
+++ b/include/drm/drm_gem_cma_helper.h
@@ -76,6 +76,11 @@ int drm_gem_cma_dumb_create(struct drm_file *file_priv,
struct drm_device *drm,
struct drm_mode_create_dumb *args);

+/* create non-coherent memory region for DRM framebuffer */
+int drm_gem_cma_dumb_create_noncoherent(struct drm_file *file_priv,
+ struct drm_device *drm,
+ struct drm_mode_create_dumb *args);
+
/* allocate physical memory */
struct drm_gem_cma_object *drm_gem_cma_create(struct drm_device *drm,
size_t size);
--
2.30.1