dma-buf: Use struct dma_buf_map in dma_buf_vmap() interfaces

This patch updates dma_buf_vmap() and dma-buf's vmap callback to use
struct dma_buf_map.

The interfaces used to return a buffer address. This address now gets
stored in an instance of the structure that is given as an additional
argument. The functions return an errno code on errors.

Users of the functions are updated accordingly. This is only an interface
change. It is currently expected that dma-buf memory can be accessed with
system memory load/store operations.

v3:
	* update fastrpc driver (kernel test robot)
v2:
	* always clear map parameter in dma_buf_vmap() (Daniel)
	* include dma-buf-heaps and i915 selftests (kernel test robot)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sumit Semwal <sumit.semwal@linaro.org>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Acked-by: Tomasz Figa <tfiga@chromium.org>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200925115601.23955-3-tzimmermann@suse.de

14 files changed, 125 insertions, 57 deletions

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 5e849ca241a0..61bd24d21b38 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1186,46 +1186,50 @@ EXPORT_SYMBOL_GPL(dma_buf_mmap);
  * dma_buf_vmap - Create virtual mapping for the buffer object into kernel
  * address space. Same restrictions as for vmap and friends apply.
  * @dmabuf:	[in]	buffer to vmap
+ * @map:	[out]	returns the vmap pointer
  *
  * This call may fail due to lack of virtual mapping address space.
  * These calls are optional in drivers. The intended use for them
  * is for mapping objects linear in kernel space for high use objects.
  * Please attempt to use kmap/kunmap before thinking about these interfaces.
  *
- * Returns NULL on error.
+ * Returns 0 on success, or a negative errno code otherwise.
  */
-void *dma_buf_vmap(struct dma_buf *dmabuf)
+int dma_buf_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
 {
-	void *ptr;
+	struct dma_buf_map ptr;
+	int ret = 0;
+
+	dma_buf_map_clear(map);
 
 	if (WARN_ON(!dmabuf))
-		return NULL;
+		return -EINVAL;
 
 	if (!dmabuf->ops->vmap)
-		return NULL;
+		return -EINVAL;
 
 	mutex_lock(&dmabuf->lock);
 	if (dmabuf->vmapping_counter) {
 		dmabuf->vmapping_counter++;
 		BUG_ON(dma_buf_map_is_null(&dmabuf->vmap_ptr));
-		ptr = dmabuf->vmap_ptr.vaddr;
+		*map = dmabuf->vmap_ptr;
 		goto out_unlock;
 	}
 
 	BUG_ON(dma_buf_map_is_set(&dmabuf->vmap_ptr));
 
-	ptr = dmabuf->ops->vmap(dmabuf);
-	if (WARN_ON_ONCE(IS_ERR(ptr)))
-		ptr = NULL;
-	if (!ptr)
+	ret = dmabuf->ops->vmap(dmabuf, &ptr);
+	if (WARN_ON_ONCE(ret))
 		goto out_unlock;
 
-	dmabuf->vmap_ptr.vaddr = ptr;
+	dmabuf->vmap_ptr = ptr;
 	dmabuf->vmapping_counter = 1;
 
+	*map = dmabuf->vmap_ptr;
+
 out_unlock:
 	mutex_unlock(&dmabuf->lock);
-	return ptr;
+	return ret;
 }
 EXPORT_SYMBOL_GPL(dma_buf_vmap);
 
diff --git a/drivers/dma-buf/heaps/heap-helpers.c b/drivers/dma-buf/heaps/heap-helpers.c
index 9f964ca3f59c..27e54d9c120c 100644
--- a/drivers/dma-buf/heaps/heap-helpers.c
+++ b/drivers/dma-buf/heaps/heap-helpers.c
@@ -236,7 +236,7 @@ static int dma_heap_dma_buf_end_cpu_access(struct dma_buf *dmabuf,
 	return 0;
 }
 
-static void *dma_heap_dma_buf_vmap(struct dma_buf *dmabuf)
+static int dma_heap_dma_buf_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
 {
 	struct heap_helper_buffer *buffer = dmabuf->priv;
 	void *vaddr;
@@ -245,7 +245,11 @@ static void *dma_heap_dma_buf_vmap(struct dma_buf *dmabuf)
 	vaddr = dma_heap_buffer_vmap_get(buffer);
 	mutex_unlock(&buffer->lock);
 
-	return vaddr;
+	if (!vaddr)
+		return -ENOMEM;
+	dma_buf_map_set_vaddr(map, vaddr);
+
+	return 0;
 }
 
 static void dma_heap_dma_buf_vunmap(struct dma_buf *dmabuf, void *vaddr)
diff --git a/drivers/gpu/drm/drm_gem_cma_helper.c b/drivers/gpu/drm/drm_gem_cma_helper.c
index 1e5b389c435c..eb412e45f896 100644
--- a/drivers/gpu/drm/drm_gem_cma_helper.c
+++ b/drivers/gpu/drm/drm_gem_cma_helper.c
@@ -634,22 +634,23 @@ drm_gem_cma_prime_import_sg_table_vmap(struct drm_device *dev,
 {
 	struct drm_gem_cma_object *cma_obj;
 	struct drm_gem_object *obj;
-	void *vaddr;
+	struct dma_buf_map map;
+	int ret;
 
-	vaddr = dma_buf_vmap(attach->dmabuf);
-	if (!vaddr) {
+	ret = dma_buf_vmap(attach->dmabuf, &map);
+	if (ret) {
 		DRM_ERROR("Failed to vmap PRIME buffer\n");
-		return ERR_PTR(-ENOMEM);
+		return ERR_PTR(ret);
 	}
 
 	obj = drm_gem_cma_prime_import_sg_table(dev, attach, sgt);
 	if (IS_ERR(obj)) {
-		dma_buf_vunmap(attach->dmabuf, vaddr);
+		dma_buf_vunmap(attach->dmabuf, map.vaddr);
 		return obj;
 	}
 
 	cma_obj = to_drm_gem_cma_obj(obj);
-	cma_obj->vaddr = vaddr;
+	cma_obj->vaddr = map.vaddr;
 
 	return obj;
 }
diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
index 0a952f27c184..ad10a57cfece 100644
--- a/drivers/gpu/drm/drm_gem_shmem_helper.c
+++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
@@ -261,13 +261,16 @@ EXPORT_SYMBOL(drm_gem_shmem_unpin);
 static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem)
 {
 	struct drm_gem_object *obj = &shmem->base;
-	int ret;
+	struct dma_buf_map map;
+	int ret = 0;
 
 	if (shmem->vmap_use_count++ > 0)
 		return shmem->vaddr;
 
 	if (obj->import_attach) {
-		shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf);
+		ret = dma_buf_vmap(obj->import_attach->dmabuf, &map);
+		if (!ret)
+			shmem->vaddr = map.vaddr;
 	} else {
 		pgprot_t prot = PAGE_KERNEL;
 
@@ -279,11 +282,12 @@ static void *drm_gem_shmem_vmap_locked(struct drm_gem_shmem_object *shmem)
 			prot = pgprot_writecombine(prot);
 		shmem->vaddr = vmap(shmem->pages, obj->size >> PAGE_SHIFT,
 				    VM_MAP, prot);
+		if (!shmem->vaddr)
+			ret = -ENOMEM;
 	}
 
-	if (!shmem->vaddr) {
-		DRM_DEBUG_KMS("Failed to vmap pages\n");
-		ret = -ENOMEM;
+	if (ret) {
+		DRM_DEBUG_KMS("Failed to vmap pages, error %d\n", ret);
 		goto err_put_pages;
 	}
 
diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
index 194784a5b344..2d75e58d21fe 100644
--- a/drivers/gpu/drm/drm_prime.c
+++ b/drivers/gpu/drm/drm_prime.c
@@ -662,22 +662,25 @@ EXPORT_SYMBOL(drm_gem_unmap_dma_buf);
 /**
  * drm_gem_dmabuf_vmap - dma_buf vmap implementation for GEM
  * @dma_buf: buffer to be mapped
+ * @map: the virtual address of the buffer
  *
  * Sets up a kernel virtual mapping. This can be used as the &dma_buf_ops.vmap
  * callback. Calls into &drm_gem_object_funcs.vmap for device specific handling.
  *
  * Returns the kernel virtual address or NULL on failure.
  */
-void *drm_gem_dmabuf_vmap(struct dma_buf *dma_buf)
+int drm_gem_dmabuf_vmap(struct dma_buf *dma_buf, struct dma_buf_map *map)
 {
 	struct drm_gem_object *obj = dma_buf->priv;
 	void *vaddr;
 
 	vaddr = drm_gem_vmap(obj);
 	if (IS_ERR(vaddr))
-		vaddr = NULL;
+		return PTR_ERR(vaddr);
 
-	return vaddr;
+	dma_buf_map_set_vaddr(map, vaddr);
+
+	return 0;
 }
 EXPORT_SYMBOL(drm_gem_dmabuf_vmap);
 
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
index 4aa3426a9ba4..80a9fc143bbb 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_prime.c
@@ -85,9 +85,15 @@ static void etnaviv_gem_prime_release(struct etnaviv_gem_object *etnaviv_obj)
 
 static void *etnaviv_gem_prime_vmap_impl(struct etnaviv_gem_object *etnaviv_obj)
 {
+	struct dma_buf_map map;
+	int ret;
+
 	lockdep_assert_held(&etnaviv_obj->lock);
 
-	return dma_buf_vmap(etnaviv_obj->base.import_attach->dmabuf);
+	ret = dma_buf_vmap(etnaviv_obj->base.import_attach->dmabuf, &map);
+	if (ret)
+		return NULL;
+	return map.vaddr;
 }
 
 static int etnaviv_gem_prime_mmap_obj(struct etnaviv_gem_object *etnaviv_obj,
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
index 27fddc22a7c6..77b363d3000b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_dmabuf.c
@@ -82,11 +82,18 @@ static void i915_gem_unmap_dma_buf(struct dma_buf_attachment *attachment,
 	i915_gem_object_unpin_pages(obj);
 }
 
-static void *i915_gem_dmabuf_vmap(struct dma_buf *dma_buf)
+static int i915_gem_dmabuf_vmap(struct dma_buf *dma_buf, struct dma_buf_map *map)
 {
 	struct drm_i915_gem_object *obj = dma_buf_to_obj(dma_buf);
+	void *vaddr;
 
-	return i915_gem_object_pin_map(obj, I915_MAP_WB);
+	vaddr = i915_gem_object_pin_map(obj, I915_MAP_WB);
+	if (IS_ERR(vaddr))
+		return PTR_ERR(vaddr);
+
+	dma_buf_map_set_vaddr(map, vaddr);
+
+	return 0;
 }
 
 static void i915_gem_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
diff --git a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
index 0845ce1ae37c..3aad7643b0b7 100644
--- a/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/selftests/i915_gem_dmabuf.c
@@ -82,6 +82,7 @@ static int igt_dmabuf_import(void *arg)
 	struct drm_i915_gem_object *obj;
 	struct dma_buf *dmabuf;
 	void *obj_map, *dma_map;
+	struct dma_buf_map map;
 	u32 pattern[] = { 0, 0xaa, 0xcc, 0x55, 0xff };
 	int err, i;
 
@@ -110,7 +111,8 @@ static int igt_dmabuf_import(void *arg)
 		goto out_obj;
 	}
 
-	dma_map = dma_buf_vmap(dmabuf);
+	err = dma_buf_vmap(dmabuf, &map);
+	dma_map = err ? NULL : map.vaddr;
 	if (!dma_map) {
 		pr_err("dma_buf_vmap failed\n");
 		err = -ENOMEM;
@@ -163,6 +165,7 @@ static int igt_dmabuf_import_ownership(void *arg)
 	struct drm_i915_private *i915 = arg;
 	struct drm_i915_gem_object *obj;
 	struct dma_buf *dmabuf;
+	struct dma_buf_map map;
 	void *ptr;
 	int err;
 
@@ -170,7 +173,8 @@ static int igt_dmabuf_import_ownership(void *arg)
 	if (IS_ERR(dmabuf))
 		return PTR_ERR(dmabuf);
 
-	ptr = dma_buf_vmap(dmabuf);
+	err = dma_buf_vmap(dmabuf, &map);
+	ptr = err ? NULL : map.vaddr;
 	if (!ptr) {
 		pr_err("dma_buf_vmap failed\n");
 		err = -ENOMEM;
@@ -212,6 +216,7 @@ static int igt_dmabuf_export_vmap(void *arg)
 	struct drm_i915_private *i915 = arg;
 	struct drm_i915_gem_object *obj;
 	struct dma_buf *dmabuf;
+	struct dma_buf_map map;
 	void *ptr;
 	int err;
 
@@ -228,7 +233,8 @@ static int igt_dmabuf_export_vmap(void *arg)
 	}
 	i915_gem_object_put(obj);
 
-	ptr = dma_buf_vmap(dmabuf);
+	err = dma_buf_vmap(dmabuf, &map);
+	ptr = err ? NULL : map.vaddr;
 	if (!ptr) {
 		pr_err("dma_buf_vmap failed\n");
 		err = -ENOMEM;
diff --git a/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c b/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c
index debaf7b18ab5..dcae46441f7d 100644
--- a/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c
+++ b/drivers/gpu/drm/i915/gem/selftests/mock_dmabuf.c
@@ -62,11 +62,17 @@ static void mock_dmabuf_release(struct dma_buf *dma_buf)
 	kfree(mock);
 }
 
-static void *mock_dmabuf_vmap(struct dma_buf *dma_buf)
+static int mock_dmabuf_vmap(struct dma_buf *dma_buf, struct dma_buf_map *map)
 {
 	struct mock_dmabuf *mock = to_mock(dma_buf);
+	void *vaddr;
 
-	return vm_map_ram(mock->pages, mock->npages, 0);
+	vaddr = vm_map_ram(mock->pages, mock->npages, 0);
+	if (!vaddr)
+		return -ENOMEM;
+	dma_buf_map_set_vaddr(map, vaddr);
+
+	return 0;
 }
 
 static void mock_dmabuf_vunmap(struct dma_buf *dma_buf, void *vaddr)
diff --git a/drivers/gpu/drm/tegra/gem.c b/drivers/gpu/drm/tegra/gem.c
index d481dea4738d..2b6e06c7a2c5 100644
--- a/drivers/gpu/drm/tegra/gem.c
+++ b/drivers/gpu/drm/tegra/gem.c
@@ -132,14 +132,18 @@ static void tegra_bo_unpin(struct device *dev, struct sg_table *sgt)
 static void *tegra_bo_mmap(struct host1x_bo *bo)
 {
 	struct tegra_bo *obj = host1x_to_tegra_bo(bo);
+	struct dma_buf_map map;
+	int ret;
 
-	if (obj->vaddr)
+	if (obj->vaddr) {
 		return obj->vaddr;
-	else if (obj->gem.import_attach)
-		return dma_buf_vmap(obj->gem.import_attach->dmabuf);
-	else
+	} else if (obj->gem.import_attach) {
+		ret = dma_buf_vmap(obj->gem.import_attach->dmabuf, &map);
+		return ret ? NULL : map.vaddr;
+	} else {
 		return vmap(obj->pages, obj->num_pages, VM_MAP,
 			    pgprot_writecombine(PAGE_KERNEL));
+	}
 }
 
 static void tegra_bo_munmap(struct host1x_bo *bo, void *addr)
@@ -649,12 +653,14 @@ static int tegra_gem_prime_mmap(struct dma_buf *buf, struct vm_area_struct *vma)
 	return __tegra_gem_mmap(gem, vma);
 }
 
-static void *tegra_gem_prime_vmap(struct dma_buf *buf)
+static int tegra_gem_prime_vmap(struct dma_buf *buf, struct dma_buf_map *map)
 {
 	struct drm_gem_object *gem = buf->priv;
 	struct tegra_bo *bo = to_tegra_bo(gem);
 
-	return bo->vaddr;
+	dma_buf_map_set_vaddr(map, bo->vaddr);
+
+	return 0;
 }
 
 static void tegra_gem_prime_vunmap(struct dma_buf *buf, void *vaddr)
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index ec3446cc45b8..11428287bdf3 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -81,9 +81,13 @@ static void *vb2_dc_cookie(void *buf_priv)
 static void *vb2_dc_vaddr(void *buf_priv)
 {
 	struct vb2_dc_buf *buf = buf_priv;
+	struct dma_buf_map map;
+	int ret;
 
-	if (!buf->vaddr && buf->db_attach)
-		buf->vaddr = dma_buf_vmap(buf->db_attach->dmabuf);
+	if (!buf->vaddr && buf->db_attach) {
+		ret = dma_buf_vmap(buf->db_attach->dmabuf, &map);
+		buf->vaddr = ret ? NULL : map.vaddr;
+	}
 
 	return buf->vaddr;
 }
@@ -365,11 +369,13 @@ vb2_dc_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf,
 	return 0;
 }
 
-static void *vb2_dc_dmabuf_ops_vmap(struct dma_buf *dbuf)
+static int vb2_dc_dmabuf_ops_vmap(struct dma_buf *dbuf, struct dma_buf_map *map)
 {
 	struct vb2_dc_buf *buf = dbuf->priv;
 
-	return buf->vaddr;
+	dma_buf_map_set_vaddr(map, buf->vaddr);
+
+	return 0;
 }
 
 static int vb2_dc_dmabuf_ops_mmap(struct dma_buf *dbuf,
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
index 0a40e00f0d7e..c51170e9c1b9 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -300,14 +300,18 @@ static void vb2_dma_sg_put_userptr(void *buf_priv)
 static void *vb2_dma_sg_vaddr(void *buf_priv)
 {
 	struct vb2_dma_sg_buf *buf = buf_priv;
+	struct dma_buf_map map;
+	int ret;
 
 	BUG_ON(!buf);
 
 	if (!buf->vaddr) {
-		if (buf->db_attach)
-			buf->vaddr = dma_buf_vmap(buf->db_attach->dmabuf);
-		else
+		if (buf->db_attach) {
+			ret = dma_buf_vmap(buf->db_attach->dmabuf, &map);
+			buf->vaddr = ret ? NULL : map.vaddr;
+		} else {
 			buf->vaddr = vm_map_ram(buf->pages, buf->num_pages, -1);
+		}
 	}
 
 	/* add offset in case userptr is not page-aligned */
@@ -489,11 +493,13 @@ vb2_dma_sg_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf,
 	return 0;
 }
 
-static void *vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf)
+static int vb2_dma_sg_dmabuf_ops_vmap(struct dma_buf *dbuf, struct dma_buf_map *map)
 {
 	struct vb2_dma_sg_buf *buf = dbuf->priv;
 
-	return vb2_dma_sg_vaddr(buf);
+	dma_buf_map_set_vaddr(map, buf->vaddr);
+
+	return 0;
 }
 
 static int vb2_dma_sg_dmabuf_ops_mmap(struct dma_buf *dbuf,
diff --git a/drivers/media/common/videobuf2/videobuf2-vmalloc.c b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
index c66fda4a65e4..7b68e2379c65 100644
--- a/drivers/media/common/videobuf2/videobuf2-vmalloc.c
+++ b/drivers/media/common/videobuf2/videobuf2-vmalloc.c
@@ -318,11 +318,13 @@ static void vb2_vmalloc_dmabuf_ops_release(struct dma_buf *dbuf)
 	vb2_vmalloc_put(dbuf->priv);
 }
 
-static void *vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf)
+static int vb2_vmalloc_dmabuf_ops_vmap(struct dma_buf *dbuf, struct dma_buf_map *map)
 {
 	struct vb2_vmalloc_buf *buf = dbuf->priv;
 
-	return buf->vaddr;
+	dma_buf_map_set_vaddr(map, buf->vaddr);
+
+	return 0;
 }
 
 static int vb2_vmalloc_dmabuf_ops_mmap(struct dma_buf *dbuf,
@@ -374,10 +376,15 @@ static struct dma_buf *vb2_vmalloc_get_dmabuf(void *buf_priv, unsigned long flag
 static int vb2_vmalloc_map_dmabuf(void *mem_priv)
 {
 	struct vb2_vmalloc_buf *buf = mem_priv;
+	struct dma_buf_map map;
+	int ret;
 
-	buf->vaddr = dma_buf_vmap(buf->dbuf);
+	ret = dma_buf_vmap(buf->dbuf, &map);
+	if (ret)
+		return -EFAULT;
+	buf->vaddr = map.vaddr;
 
-	return buf->vaddr ? 0 : -EFAULT;
+	return 0;
 }
 
 static void vb2_vmalloc_unmap_dmabuf(void *mem_priv)
diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 7939c55daceb..b39e198533f0 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -581,11 +581,13 @@ static void fastrpc_dma_buf_detatch(struct dma_buf *dmabuf,
 	kfree(a);
 }
 
-static void *fastrpc_vmap(struct dma_buf *dmabuf)
+static int fastrpc_vmap(struct dma_buf *dmabuf, struct dma_buf_map *map)
 {
 	struct fastrpc_buf *buf = dmabuf->priv;
 
-	return buf->virt;
+	dma_buf_map_set_vaddr(map, buf->virt);
+
+	return 0;
 }
 
 static int fastrpc_mmap(struct dma_buf *dmabuf,