[PATCH v2] drm/exynos: use prime helpers

[Aaron Plattner <aplattner@nvidia.com>]

Simplify the Exynos prime implementation by using the default behavior provided
by drm_gem_prime_import and drm_gem_prime_export.

Signed-off-by: Aaron Plattner <aplattner@nvidia.com>
---
v2: fix dumb mistakes now that I have a toolchain that can compile-test this

 drivers/gpu/drm/exynos/exynos_drm_dmabuf.c | 156 ++---------------------------
 drivers/gpu/drm/exynos/exynos_drm_dmabuf.h |  13 ++-
 drivers/gpu/drm/exynos/exynos_drm_drv.c    |   2 +
 3 files changed, 20 insertions(+), 151 deletions(-)

diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
index 539da9f..71b40f4 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
@@ -28,8 +28,6 @@
 #include "exynos_drm_drv.h"
 #include "exynos_drm_gem.h"
 
-#include <linux/dma-buf.h>
-
 static struct sg_table *exynos_get_sgt(struct drm_device *drm_dev,
 					struct exynos_drm_gem_buf *buf)
 {
@@ -56,15 +54,12 @@ out:
 	return NULL;
 }
 
-static struct sg_table *
-		exynos_gem_map_dma_buf(struct dma_buf_attachment *attach,
-					enum dma_data_direction dir)
+struct sg_table *exynos_gem_prime_get_pages(struct drm_gem_object *obj)
 {
-	struct exynos_drm_gem_obj *gem_obj = attach->dmabuf->priv;
+	struct exynos_drm_gem_obj *gem_obj = to_exynos_gem_obj(obj);
 	struct drm_device *dev = gem_obj->base.dev;
 	struct exynos_drm_gem_buf *buf;
 	struct sg_table *sgt = NULL;
-	int nents;
 
 	DRM_DEBUG_PRIME("%s\n", __FILE__);
 
@@ -74,120 +69,20 @@ static struct sg_table *
 		return sgt;
 	}
 
-	mutex_lock(&dev->struct_mutex);
-
 	sgt = exynos_get_sgt(dev, buf);
 	if (!sgt)
-		goto err_unlock;
-
-	nents = dma_map_sg(attach->dev, sgt->sgl, sgt->nents, dir);
-	if (!nents) {
-		DRM_ERROR("failed to map sgl with iommu.\n");
-		sgt = NULL;
-		goto err_unlock;
-	}
+		goto err;
 
 	DRM_DEBUG_PRIME("buffer size = 0x%lx\n", buf->size);
 
-err_unlock:
-	mutex_unlock(&dev->struct_mutex);
+err:
 	return sgt;
 }
 
-static void exynos_gem_unmap_dma_buf(struct dma_buf_attachment *attach,
-						struct sg_table *sgt,
-						enum dma_data_direction dir)
-{
-	dma_unmap_sg(attach->dev, sgt->sgl, sgt->nents, dir);
-
-	sg_free_table(sgt);
-	kfree(sgt);
-	sgt = NULL;
-}
-
-static void exynos_dmabuf_release(struct dma_buf *dmabuf)
+struct drm_gem_object *exynos_gem_prime_import_sg(struct drm_device *dev,
+						  size_t size,
+						  struct sg_table *sgt)
 {
-	struct exynos_drm_gem_obj *exynos_gem_obj = dmabuf->priv;
-
-	DRM_DEBUG_PRIME("%s\n", __FILE__);
-
-	/*
-	 * exynos_dmabuf_release() call means that file object's
-	 * f_count is 0 and it calls drm_gem_object_handle_unreference()
-	 * to drop the references that these values had been increased
-	 * at drm_prime_handle_to_fd()
-	 */
-	if (exynos_gem_obj->base.export_dma_buf == dmabuf) {
-		exynos_gem_obj->base.export_dma_buf = NULL;
-
-		/*
-		 * drop this gem object refcount to release allocated buffer
-		 * and resources.
-		 */
-		drm_gem_object_unreference_unlocked(&exynos_gem_obj->base);
-	}
-}
-
-static void *exynos_gem_dmabuf_kmap_atomic(struct dma_buf *dma_buf,
-						unsigned long page_num)
-{
-	/* TODO */
-
-	return NULL;
-}
-
-static void exynos_gem_dmabuf_kunmap_atomic(struct dma_buf *dma_buf,
-						unsigned long page_num,
-						void *addr)
-{
-	/* TODO */
-}
-
-static void *exynos_gem_dmabuf_kmap(struct dma_buf *dma_buf,
-					unsigned long page_num)
-{
-	/* TODO */
-
-	return NULL;
-}
-
-static void exynos_gem_dmabuf_kunmap(struct dma_buf *dma_buf,
-					unsigned long page_num, void *addr)
-{
-	/* TODO */
-}
-
-static int exynos_gem_dmabuf_mmap(struct dma_buf *dma_buf,
-	struct vm_area_struct *vma)
-{
-	return -ENOTTY;
-}
-
-static struct dma_buf_ops exynos_dmabuf_ops = {
-	.map_dma_buf		= exynos_gem_map_dma_buf,
-	.unmap_dma_buf		= exynos_gem_unmap_dma_buf,
-	.kmap			= exynos_gem_dmabuf_kmap,
-	.kmap_atomic		= exynos_gem_dmabuf_kmap_atomic,
-	.kunmap			= exynos_gem_dmabuf_kunmap,
-	.kunmap_atomic		= exynos_gem_dmabuf_kunmap_atomic,
-	.mmap			= exynos_gem_dmabuf_mmap,
-	.release		= exynos_dmabuf_release,
-};
-
-struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
-				struct drm_gem_object *obj, int flags)
-{
-	struct exynos_drm_gem_obj *exynos_gem_obj = to_exynos_gem_obj(obj);
-
-	return dma_buf_export(exynos_gem_obj, &exynos_dmabuf_ops,
-				exynos_gem_obj->base.size, 0600);
-}
-
-struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
-				struct dma_buf *dma_buf)
-{
-	struct dma_buf_attachment *attach;
-	struct sg_table *sgt;
 	struct scatterlist *sgl;
 	struct exynos_drm_gem_obj *exynos_gem_obj;
 	struct exynos_drm_gem_buf *buffer;
@@ -195,39 +90,13 @@ struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 
 	DRM_DEBUG_PRIME("%s\n", __FILE__);
 
-	/* is this one of own objects? */
-	if (dma_buf->ops == &exynos_dmabuf_ops) {
-		struct drm_gem_object *obj;
-
-		exynos_gem_obj = dma_buf->priv;
-		obj = &exynos_gem_obj->base;
-
-		/* is it from our device? */
-		if (obj->dev == drm_dev) {
-			drm_gem_object_reference(obj);
-			return obj;
-		}
-	}
-
-	attach = dma_buf_attach(dma_buf, drm_dev->dev);
-	if (IS_ERR(attach))
-		return ERR_PTR(-EINVAL);
-
-
-	sgt = dma_buf_map_attachment(attach, DMA_BIDIRECTIONAL);
-	if (IS_ERR_OR_NULL(sgt)) {
-		ret = PTR_ERR(sgt);
-		goto err_buf_detach;
-	}
-
 	buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
 	if (!buffer) {
 		DRM_ERROR("failed to allocate exynos_drm_gem_buf.\n");
-		ret = -ENOMEM;
-		goto err_unmap_attach;
+		return ERR_PTR(-ENOMEM);
 	}
 
-	exynos_gem_obj = exynos_drm_gem_init(drm_dev, dma_buf->size);
+	exynos_gem_obj = exynos_drm_gem_init(dev, size);
 	if (!exynos_gem_obj) {
 		ret = -ENOMEM;
 		goto err_free_buffer;
@@ -235,7 +104,7 @@ struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 
 	sgl = sgt->sgl;
 
-	buffer->size = dma_buf->size;
+	buffer->size = size;
 	buffer->dma_addr = sg_dma_address(sgl);
 
 	if (sgt->nents == 1) {
@@ -253,7 +122,6 @@ struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 
 	exynos_gem_obj->buffer = buffer;
 	buffer->sgt = sgt;
-	exynos_gem_obj->base.import_attach = attach;
 
 	DRM_DEBUG_PRIME("dma_addr = 0x%x, size = 0x%lx\n", buffer->dma_addr,
 								buffer->size);
@@ -263,10 +131,6 @@ struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
 err_free_buffer:
 	kfree(buffer);
 	buffer = NULL;
-err_unmap_attach:
-	dma_buf_unmap_attachment(attach, sgt, DMA_BIDIRECTIONAL);
-err_buf_detach:
-	dma_buf_detach(dma_buf, attach);
 	return ERR_PTR(ret);
 }
 
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.h b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.h
index 662a8f9..f198183 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.h
+++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.h
@@ -27,13 +27,16 @@
 #define _EXYNOS_DRM_DMABUF_H_
 
 #ifdef CONFIG_DRM_EXYNOS_DMABUF
-struct dma_buf *exynos_dmabuf_prime_export(struct drm_device *drm_dev,
-				struct drm_gem_object *obj, int flags);
-
-struct drm_gem_object *exynos_dmabuf_prime_import(struct drm_device *drm_dev,
-						struct dma_buf *dma_buf);
+#define exynos_dmabuf_prime_export		drm_gem_prime_export
+#define exynos_dmabuf_prime_import		drm_gem_prime_import
+struct sg_table *exynos_gem_prime_get_pages(struct drm_gem_object *obj);
+struct drm_gem_object *exynos_gem_prime_import_sg(struct drm_device *dev,
+						  size_t size,
+						  struct sg_table *sg);
 #else
 #define exynos_dmabuf_prime_export		NULL
 #define exynos_dmabuf_prime_import		NULL
+#define exynos_gem_prime_get_pages		NULL
+#define exynos_gem_prime_import_sg		NULL
 #endif
 #endif
diff --git a/drivers/gpu/drm/exynos/exynos_drm_drv.c b/drivers/gpu/drm/exynos/exynos_drm_drv.c
index 2b287d2..2a04e97 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_drv.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_drv.c
@@ -283,6 +283,8 @@ static struct drm_driver exynos_drm_driver = {
 	.prime_fd_to_handle	= drm_gem_prime_fd_to_handle,
 	.gem_prime_export	= exynos_dmabuf_prime_export,
 	.gem_prime_import	= exynos_dmabuf_prime_import,
+	.gem_prime_get_pages	= exynos_gem_prime_get_pages,
+	.gem_prime_import_sg	= exynos_gem_prime_import_sg,
 	.ioctls			= exynos_ioctls,
 	.fops			= &exynos_drm_driver_fops,
 	.name	= DRIVER_NAME,
-- 
1.8.0.1