drm/gem: Use struct dma_buf_map in GEM vmap ops and convert GEM backends

This patch replaces the vmap/vunmap's use of raw pointers in GEM object
functions with instances of struct dma_buf_map. GEM backends are
converted as well. For most of them, this simply changes the returned type.

TTM-based drivers now return information about the location of the memory,
either system or I/O memory. GEM VRAM helpers and qxl now use ttm_bo_vmap()
et al. Amdgpu, nouveau and radeon use drm_gem_ttm_vmap() et al instead of
implementing their own vmap callbacks.

v7:
	* init QXL cursor to mapped BO buffer (kernel test robot)
v5:
	* update vkms after switch to shmem
v4:
	* use ttm_bo_vmap(), drm_gem_ttm_vmap(), et al. (Daniel, Christian)
	* fix a trailing { in drm_gem_vmap()
	* remove several empty functions instead of converting them (Daniel)
	* comment uses of raw pointers with a TODO (Daniel)
	* TODO list: convert more helpers to use struct dma_buf_map

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Christian König <christian.koenig@amd.com>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20201103093015.1063-7-tzimmermann@suse.de

1 files changed, 29 insertions, 19 deletions

diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 8233bda4692f..499189c48f0b 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -258,19 +258,25 @@ void drm_gem_shmem_unpin(struct drm_gem_object *obj)
 }
 EXPORT_SYMBOL(drm_gem_shmem_unpin);
 
-static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem)
+static int drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem, struct dma_buf_map *map)
 {
 	struct drm_gem_object *obj = &shmem->base;
-	struct dma_buf_map map;
 	int ret = 0;
 
-	if (shmem->vmap_use_count++ > 0)
-		return shmem->vaddr;
+	if (shmem->vmap_use_count++ > 0) {
+		dma_buf_map_set_vaddr(map, shmem->vaddr);
+		return 0;
+	}
 
 	if (obj->import_attach) {
-		ret = dma_buf_vmap(obj->import_attach->dmabuf, &map);
-		if (!ret)
-			shmem->vaddr = map.vaddr;
+		ret = dma_buf_vmap(obj->import_attach->dmabuf, map);
+		if (!ret) {
+			if (WARN_ON(map->is_iomem)) {
+				ret = -EIO;
+				goto err_put_pages;
+			}
+			shmem->vaddr = map->vaddr;
+		}
 	} else {
 		pgprot_t prot = PAGE_KERNEL;
 
@@ -284,6 +290,8 @@ static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem)
 				    VM_MAP, prot);
 		if (!shmem->vaddr)
 			ret = -ENOMEM;
+		else
+			dma_buf_map_set_vaddr(map, shmem->vaddr);
 	}
 
 	if (ret) {
@@ -291,7 +299,7 @@ static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem)
 		goto err_put_pages;
 	}
 
-	return shmem->vaddr;
+	return 0;
 
 err_put_pages:
 	if (!obj->import_attach)
@@ -299,12 +307,14 @@ err_put_pages:
 err_zero_use:
 	shmem->vmap_use_count = 0;
 
-	return ERR_PTR(ret);
+	return ret;
 }
 
 /*
  * drm_gem_shmem_vmap - Create a virtual mapping for a shmem GEM object
  * @shmem: shmem GEM object
+ * @map: Returns the kernel virtual address of the SHMEM GEM object's backing
+ *       store.
  *
  * This function makes sure that a contiguous kernel virtual address mapping
  * exists for the buffer backing the shmem GEM object.
@@ -318,26 +328,25 @@ err_zero_use:
  * Returns:
  * 0 on success or a negative error code on failure.
  */
-void *drm_gem_shmem_vmap(struct drm_gem_object *obj)
+int drm_gem_shmem_vmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
-	void *vaddr;
 	int ret;
 
 	ret = mutex_lock_interruptible(&shmem->vmap_lock);
 	if (ret)
-		return ERR_PTR(ret);
-	vaddr = drm_gem_shmem_vmap_locked(shmem);
+		return ret;
+	ret = drm_gem_shmem_vmap_locked(shmem, map);
 	mutex_unlock(&shmem->vmap_lock);
 
-	return vaddr;
+	return ret;
 }
 EXPORT_SYMBOL(drm_gem_shmem_vmap);
 
-static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem)
+static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem,
+					struct dma_buf_map *map)
 {
 	struct drm_gem_object *obj = &shmem->base;
-	struct dma_buf_map map = DMA_BUF_MAP_INIT_VADDR(shmem->vaddr);
 
 	if (WARN_ON_ONCE(!shmem->vmap_use_count))
 		return;
@@ -346,7 +355,7 @@ static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem)
 		return;
 
 	if (obj->import_attach)
-		dma_buf_vunmap(obj->import_attach->dmabuf, &map);
+		dma_buf_vunmap(obj->import_attach->dmabuf, map);
 	else
 		vunmap(shmem->vaddr);
 
@@ -357,6 +366,7 @@ static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem)
 /*
  * drm_gem_shmem_vunmap - Unmap a virtual mapping fo a shmem GEM object
  * @shmem: shmem GEM object
+ * @map: Kernel virtual address where the SHMEM GEM object was mapped
  *
  * This function cleans up a kernel virtual address mapping acquired by
  * drm_gem_shmem_vmap(). The mapping is only removed when the use count drops to
@@ -366,12 +376,12 @@ static void drm_gem_shmem_vunmap_locked(struct drm_gem_shmem_object *shmem)
  * also be called by drivers directly, in which case it will hide the
  * differences between dma-buf imported and natively allocated objects.
  */
-void drm_gem_shmem_vunmap(struct drm_gem_object *obj, void *vaddr)
+void drm_gem_shmem_vunmap(struct drm_gem_object *obj, struct dma_buf_map *map)
 {
 	struct drm_gem_shmem_object *shmem = to_drm_gem_shmem_obj(obj);
 
 	mutex_lock(&shmem->vmap_lock);
-	drm_gem_shmem_vunmap_locked(shmem);
+	drm_gem_shmem_vunmap_locked(shmem, map);
 	mutex_unlock(&shmem->vmap_lock);
 }
 EXPORT_SYMBOL(drm_gem_shmem_vunmap);