diff mbox series

[v5,05/10] drm/ttm: Add vmap/vunmap to TTM and TTM GEM helpers

Message ID 20201020122046.31167-6-tzimmermann@suse.de
State Superseded
Headers show
Series Support GEM object mappings from I/O memory | expand

Commit Message

Thomas Zimmermann Oct. 20, 2020, 12:20 p.m. UTC
The new functions ttm_bo_{vmap,vunmap}() map and unmap a TTM BO in kernel
address space. The mapping's address is returned as struct dma_buf_map.
Each function is a simplified version of TTM's existing kmap code. Both
functions respect the memory's location ani/or writecombine flags.

On top TTM's functions, GEM TTM helpers got drm_gem_ttm_{vmap,vunmap}(),
two helpers that convert a GEM object into the TTM BO and forward the call
to TTM's vmap/vunmap. These helpers can be dropped into the rsp GEM object
callbacks.

v5:
	* use size_t for storing mapping size (Christian)
	* ignore premapped memory areas correctly in ttm_bo_vunmap()
	* rebase onto latest TTM interfaces (Christian)
	* remove BUG() from ttm_bo_vmap() (Christian)
v4:
	* drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel,
	  Christian)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Tested-by: Sam Ravnborg <sam@ravnborg.org>
---
 drivers/gpu/drm/drm_gem_ttm_helper.c | 38 +++++++++++++++
 drivers/gpu/drm/ttm/ttm_bo_util.c    | 72 ++++++++++++++++++++++++++++
 include/drm/drm_gem_ttm_helper.h     |  6 +++
 include/drm/ttm/ttm_bo_api.h         | 28 +++++++++++
 include/linux/dma-buf-map.h          | 20 ++++++++
 5 files changed, 164 insertions(+)

Comments

Christian König Oct. 20, 2020, 1:39 p.m. UTC | #1
Am 20.10.20 um 14:20 schrieb Thomas Zimmermann:
> The new functions ttm_bo_{vmap,vunmap}() map and unmap a TTM BO in kernel

> address space. The mapping's address is returned as struct dma_buf_map.

> Each function is a simplified version of TTM's existing kmap code. Both

> functions respect the memory's location ani/or writecombine flags.

>

> On top TTM's functions, GEM TTM helpers got drm_gem_ttm_{vmap,vunmap}(),

> two helpers that convert a GEM object into the TTM BO and forward the call

> to TTM's vmap/vunmap. These helpers can be dropped into the rsp GEM object

> callbacks.

>

> v5:

> 	* use size_t for storing mapping size (Christian)

> 	* ignore premapped memory areas correctly in ttm_bo_vunmap()

> 	* rebase onto latest TTM interfaces (Christian)

> 	* remove BUG() from ttm_bo_vmap() (Christian)

> v4:

> 	* drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel,

> 	  Christian)

>

> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

> Tested-by: Sam Ravnborg <sam@ravnborg.org>


Reviewed-by: Christian König <christian.koenig@amd.com>


> ---

>   drivers/gpu/drm/drm_gem_ttm_helper.c | 38 +++++++++++++++

>   drivers/gpu/drm/ttm/ttm_bo_util.c    | 72 ++++++++++++++++++++++++++++

>   include/drm/drm_gem_ttm_helper.h     |  6 +++

>   include/drm/ttm/ttm_bo_api.h         | 28 +++++++++++

>   include/linux/dma-buf-map.h          | 20 ++++++++

>   5 files changed, 164 insertions(+)

>

> diff --git a/drivers/gpu/drm/drm_gem_ttm_helper.c b/drivers/gpu/drm/drm_gem_ttm_helper.c

> index 0e4fb9ba43ad..db4c14d78a30 100644

> --- a/drivers/gpu/drm/drm_gem_ttm_helper.c

> +++ b/drivers/gpu/drm/drm_gem_ttm_helper.c

> @@ -49,6 +49,44 @@ void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent,

>   }

>   EXPORT_SYMBOL(drm_gem_ttm_print_info);

>   

> +/**

> + * drm_gem_ttm_vmap() - vmap &ttm_buffer_object

> + * @gem: GEM object.

> + * @map: [out] returns the dma-buf mapping.

> + *

> + * Maps a GEM object with ttm_bo_vmap(). This function can be used as

> + * &drm_gem_object_funcs.vmap callback.

> + *

> + * Returns:

> + * 0 on success, or a negative errno code otherwise.

> + */

> +int drm_gem_ttm_vmap(struct drm_gem_object *gem,

> +		     struct dma_buf_map *map)

> +{

> +	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);

> +

> +	return ttm_bo_vmap(bo, map);

> +

> +}

> +EXPORT_SYMBOL(drm_gem_ttm_vmap);

> +

> +/**

> + * drm_gem_ttm_vunmap() - vunmap &ttm_buffer_object

> + * @gem: GEM object.

> + * @map: dma-buf mapping.

> + *

> + * Unmaps a GEM object with ttm_bo_vunmap(). This function can be used as

> + * &drm_gem_object_funcs.vmap callback.

> + */

> +void drm_gem_ttm_vunmap(struct drm_gem_object *gem,

> +			struct dma_buf_map *map)

> +{

> +	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);

> +

> +	ttm_bo_vunmap(bo, map);

> +}

> +EXPORT_SYMBOL(drm_gem_ttm_vunmap);

> +

>   /**

>    * drm_gem_ttm_mmap() - mmap &ttm_buffer_object

>    * @gem: GEM object.

> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c

> index ba7ab5ed85d0..5c79418405ea 100644

> --- a/drivers/gpu/drm/ttm/ttm_bo_util.c

> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c

> @@ -32,6 +32,7 @@

>   #include <drm/ttm/ttm_bo_driver.h>

>   #include <drm/ttm/ttm_placement.h>

>   #include <drm/drm_vma_manager.h>

> +#include <linux/dma-buf-map.h>

>   #include <linux/io.h>

>   #include <linux/highmem.h>

>   #include <linux/wait.h>

> @@ -527,6 +528,77 @@ void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)

>   }

>   EXPORT_SYMBOL(ttm_bo_kunmap);

>   

> +int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)

> +{

> +	struct ttm_resource *mem = &bo->mem;

> +	int ret;

> +

> +	ret = ttm_mem_io_reserve(bo->bdev, mem);

> +	if (ret)

> +		return ret;

> +

> +	if (mem->bus.is_iomem) {

> +		void __iomem *vaddr_iomem;

> +		size_t size = bo->num_pages << PAGE_SHIFT;

> +

> +		if (mem->bus.addr)

> +			vaddr_iomem = (void __iomem *)mem->bus.addr;

> +		else if (mem->bus.caching == ttm_write_combined)

> +			vaddr_iomem = ioremap_wc(mem->bus.offset, size);

> +		else

> +			vaddr_iomem = ioremap(mem->bus.offset, size);

> +

> +		if (!vaddr_iomem)

> +			return -ENOMEM;

> +

> +		dma_buf_map_set_vaddr_iomem(map, vaddr_iomem);

> +

> +	} else {

> +		struct ttm_operation_ctx ctx = {

> +			.interruptible = false,

> +			.no_wait_gpu = false

> +		};

> +		struct ttm_tt *ttm = bo->ttm;

> +		pgprot_t prot;

> +		void *vaddr;

> +

> +		ret = ttm_tt_populate(bo->bdev, ttm, &ctx);

> +		if (ret)

> +			return ret;

> +

> +		/*

> +		 * We need to use vmap to get the desired page protection

> +		 * or to make the buffer object look contiguous.

> +		 */

> +		prot = ttm_io_prot(bo, mem, PAGE_KERNEL);

> +		vaddr = vmap(ttm->pages, bo->num_pages, 0, prot);

> +		if (!vaddr)

> +			return -ENOMEM;

> +

> +		dma_buf_map_set_vaddr(map, vaddr);

> +	}

> +

> +	return 0;

> +}

> +EXPORT_SYMBOL(ttm_bo_vmap);

> +

> +void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)

> +{

> +	struct ttm_resource *mem = &bo->mem;

> +

> +	if (dma_buf_map_is_null(map))

> +		return;

> +

> +	if (!map->is_iomem)

> +		vunmap(map->vaddr);

> +	else if (!mem->bus.addr)

> +		iounmap(map->vaddr_iomem);

> +	dma_buf_map_clear(map);

> +

> +	ttm_mem_io_free(bo->bdev, &bo->mem);

> +}

> +EXPORT_SYMBOL(ttm_bo_vunmap);

> +

>   static int ttm_bo_wait_free_node(struct ttm_buffer_object *bo,

>   				 bool dst_use_tt)

>   {

> diff --git a/include/drm/drm_gem_ttm_helper.h b/include/drm/drm_gem_ttm_helper.h

> index 118cef76f84f..7c6d874910b8 100644

> --- a/include/drm/drm_gem_ttm_helper.h

> +++ b/include/drm/drm_gem_ttm_helper.h

> @@ -10,11 +10,17 @@

>   #include <drm/ttm/ttm_bo_api.h>

>   #include <drm/ttm/ttm_bo_driver.h>

>   

> +struct dma_buf_map;

> +

>   #define drm_gem_ttm_of_gem(gem_obj) \

>   	container_of(gem_obj, struct ttm_buffer_object, base)

>   

>   void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent,

>   			    const struct drm_gem_object *gem);

> +int drm_gem_ttm_vmap(struct drm_gem_object *gem,

> +		     struct dma_buf_map *map);

> +void drm_gem_ttm_vunmap(struct drm_gem_object *gem,

> +			struct dma_buf_map *map);

>   int drm_gem_ttm_mmap(struct drm_gem_object *gem,

>   		     struct vm_area_struct *vma);

>   

> diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h

> index 37102e45e496..2c59a785374c 100644

> --- a/include/drm/ttm/ttm_bo_api.h

> +++ b/include/drm/ttm/ttm_bo_api.h

> @@ -48,6 +48,8 @@ struct ttm_bo_global;

>   

>   struct ttm_bo_device;

>   

> +struct dma_buf_map;

> +

>   struct drm_mm_node;

>   

>   struct ttm_placement;

> @@ -494,6 +496,32 @@ int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,

>    */

>   void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);

>   

> +/**

> + * ttm_bo_vmap

> + *

> + * @bo: The buffer object.

> + * @map: pointer to a struct dma_buf_map representing the map.

> + *

> + * Sets up a kernel virtual mapping, using ioremap or vmap to the

> + * data in the buffer object. The parameter @map returns the virtual

> + * address as struct dma_buf_map. Unmap the buffer with ttm_bo_vunmap().

> + *

> + * Returns

> + * -ENOMEM: Out of memory.

> + * -EINVAL: Invalid range.

> + */

> +int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);

> +

> +/**

> + * ttm_bo_vunmap

> + *

> + * @bo: The buffer object.

> + * @map: Object describing the map to unmap.

> + *

> + * Unmaps a kernel map set up by ttm_bo_vmap().

> + */

> +void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);

> +

>   /**

>    * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.

>    *

> diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h

> index fd1aba545fdf..2e8bbecb5091 100644

> --- a/include/linux/dma-buf-map.h

> +++ b/include/linux/dma-buf-map.h

> @@ -45,6 +45,12 @@

>    *

>    *	dma_buf_map_set_vaddr(&map. 0xdeadbeaf);

>    *

> + * To set an address in I/O memory, use dma_buf_map_set_vaddr_iomem().

> + *

> + * .. code-block:: c

> + *

> + *	dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf);

> + *

>    * Test if a mapping is valid with either dma_buf_map_is_set() or

>    * dma_buf_map_is_null().

>    *

> @@ -118,6 +124,20 @@ static inline void dma_buf_map_set_vaddr(struct dma_buf_map *map, void *vaddr)

>   	map->is_iomem = false;

>   }

>   

> +/**

> + * dma_buf_map_set_vaddr_iomem - Sets a dma-buf mapping structure to an address in I/O memory

> + * @map:		The dma-buf mapping structure

> + * @vaddr_iomem:	An I/O-memory address

> + *

> + * Sets the address and the I/O-memory flag.

> + */

> +static inline void dma_buf_map_set_vaddr_iomem(struct dma_buf_map *map,

> +					       void __iomem *vaddr_iomem)

> +{

> +	map->vaddr_iomem = vaddr_iomem;

> +	map->is_iomem = true;

> +}

> +

>   /**

>    * dma_buf_map_is_equal - Compares two dma-buf mapping structures for equality

>    * @lhs:	The dma-buf mapping structure
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_gem_ttm_helper.c b/drivers/gpu/drm/drm_gem_ttm_helper.c
index 0e4fb9ba43ad..db4c14d78a30 100644
--- a/drivers/gpu/drm/drm_gem_ttm_helper.c
+++ b/drivers/gpu/drm/drm_gem_ttm_helper.c
@@ -49,6 +49,44 @@  void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent,
 }
 EXPORT_SYMBOL(drm_gem_ttm_print_info);
 
+/**
+ * drm_gem_ttm_vmap() - vmap &ttm_buffer_object
+ * @gem: GEM object.
+ * @map: [out] returns the dma-buf mapping.
+ *
+ * Maps a GEM object with ttm_bo_vmap(). This function can be used as
+ * &drm_gem_object_funcs.vmap callback.
+ *
+ * Returns:
+ * 0 on success, or a negative errno code otherwise.
+ */
+int drm_gem_ttm_vmap(struct drm_gem_object *gem,
+		     struct dma_buf_map *map)
+{
+	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
+
+	return ttm_bo_vmap(bo, map);
+
+}
+EXPORT_SYMBOL(drm_gem_ttm_vmap);
+
+/**
+ * drm_gem_ttm_vunmap() - vunmap &ttm_buffer_object
+ * @gem: GEM object.
+ * @map: dma-buf mapping.
+ *
+ * Unmaps a GEM object with ttm_bo_vunmap(). This function can be used as
+ * &drm_gem_object_funcs.vmap callback.
+ */
+void drm_gem_ttm_vunmap(struct drm_gem_object *gem,
+			struct dma_buf_map *map)
+{
+	struct ttm_buffer_object *bo = drm_gem_ttm_of_gem(gem);
+
+	ttm_bo_vunmap(bo, map);
+}
+EXPORT_SYMBOL(drm_gem_ttm_vunmap);
+
 /**
  * drm_gem_ttm_mmap() - mmap &ttm_buffer_object
  * @gem: GEM object.
diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index ba7ab5ed85d0..5c79418405ea 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -32,6 +32,7 @@ 
 #include <drm/ttm/ttm_bo_driver.h>
 #include <drm/ttm/ttm_placement.h>
 #include <drm/drm_vma_manager.h>
+#include <linux/dma-buf-map.h>
 #include <linux/io.h>
 #include <linux/highmem.h>
 #include <linux/wait.h>
@@ -527,6 +528,77 @@  void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map)
 }
 EXPORT_SYMBOL(ttm_bo_kunmap);
 
+int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)
+{
+	struct ttm_resource *mem = &bo->mem;
+	int ret;
+
+	ret = ttm_mem_io_reserve(bo->bdev, mem);
+	if (ret)
+		return ret;
+
+	if (mem->bus.is_iomem) {
+		void __iomem *vaddr_iomem;
+		size_t size = bo->num_pages << PAGE_SHIFT;
+
+		if (mem->bus.addr)
+			vaddr_iomem = (void __iomem *)mem->bus.addr;
+		else if (mem->bus.caching == ttm_write_combined)
+			vaddr_iomem = ioremap_wc(mem->bus.offset, size);
+		else
+			vaddr_iomem = ioremap(mem->bus.offset, size);
+
+		if (!vaddr_iomem)
+			return -ENOMEM;
+
+		dma_buf_map_set_vaddr_iomem(map, vaddr_iomem);
+
+	} else {
+		struct ttm_operation_ctx ctx = {
+			.interruptible = false,
+			.no_wait_gpu = false
+		};
+		struct ttm_tt *ttm = bo->ttm;
+		pgprot_t prot;
+		void *vaddr;
+
+		ret = ttm_tt_populate(bo->bdev, ttm, &ctx);
+		if (ret)
+			return ret;
+
+		/*
+		 * We need to use vmap to get the desired page protection
+		 * or to make the buffer object look contiguous.
+		 */
+		prot = ttm_io_prot(bo, mem, PAGE_KERNEL);
+		vaddr = vmap(ttm->pages, bo->num_pages, 0, prot);
+		if (!vaddr)
+			return -ENOMEM;
+
+		dma_buf_map_set_vaddr(map, vaddr);
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(ttm_bo_vmap);
+
+void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map)
+{
+	struct ttm_resource *mem = &bo->mem;
+
+	if (dma_buf_map_is_null(map))
+		return;
+
+	if (!map->is_iomem)
+		vunmap(map->vaddr);
+	else if (!mem->bus.addr)
+		iounmap(map->vaddr_iomem);
+	dma_buf_map_clear(map);
+
+	ttm_mem_io_free(bo->bdev, &bo->mem);
+}
+EXPORT_SYMBOL(ttm_bo_vunmap);
+
 static int ttm_bo_wait_free_node(struct ttm_buffer_object *bo,
 				 bool dst_use_tt)
 {
diff --git a/include/drm/drm_gem_ttm_helper.h b/include/drm/drm_gem_ttm_helper.h
index 118cef76f84f..7c6d874910b8 100644
--- a/include/drm/drm_gem_ttm_helper.h
+++ b/include/drm/drm_gem_ttm_helper.h
@@ -10,11 +10,17 @@ 
 #include <drm/ttm/ttm_bo_api.h>
 #include <drm/ttm/ttm_bo_driver.h>
 
+struct dma_buf_map;
+
 #define drm_gem_ttm_of_gem(gem_obj) \
 	container_of(gem_obj, struct ttm_buffer_object, base)
 
 void drm_gem_ttm_print_info(struct drm_printer *p, unsigned int indent,
 			    const struct drm_gem_object *gem);
+int drm_gem_ttm_vmap(struct drm_gem_object *gem,
+		     struct dma_buf_map *map);
+void drm_gem_ttm_vunmap(struct drm_gem_object *gem,
+			struct dma_buf_map *map);
 int drm_gem_ttm_mmap(struct drm_gem_object *gem,
 		     struct vm_area_struct *vma);
 
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 37102e45e496..2c59a785374c 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -48,6 +48,8 @@  struct ttm_bo_global;
 
 struct ttm_bo_device;
 
+struct dma_buf_map;
+
 struct drm_mm_node;
 
 struct ttm_placement;
@@ -494,6 +496,32 @@  int ttm_bo_kmap(struct ttm_buffer_object *bo, unsigned long start_page,
  */
 void ttm_bo_kunmap(struct ttm_bo_kmap_obj *map);
 
+/**
+ * ttm_bo_vmap
+ *
+ * @bo: The buffer object.
+ * @map: pointer to a struct dma_buf_map representing the map.
+ *
+ * Sets up a kernel virtual mapping, using ioremap or vmap to the
+ * data in the buffer object. The parameter @map returns the virtual
+ * address as struct dma_buf_map. Unmap the buffer with ttm_bo_vunmap().
+ *
+ * Returns
+ * -ENOMEM: Out of memory.
+ * -EINVAL: Invalid range.
+ */
+int ttm_bo_vmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);
+
+/**
+ * ttm_bo_vunmap
+ *
+ * @bo: The buffer object.
+ * @map: Object describing the map to unmap.
+ *
+ * Unmaps a kernel map set up by ttm_bo_vmap().
+ */
+void ttm_bo_vunmap(struct ttm_buffer_object *bo, struct dma_buf_map *map);
+
 /**
  * ttm_bo_mmap_obj - mmap memory backed by a ttm buffer object.
  *
diff --git a/include/linux/dma-buf-map.h b/include/linux/dma-buf-map.h
index fd1aba545fdf..2e8bbecb5091 100644
--- a/include/linux/dma-buf-map.h
+++ b/include/linux/dma-buf-map.h
@@ -45,6 +45,12 @@ 
  *
  *	dma_buf_map_set_vaddr(&map. 0xdeadbeaf);
  *
+ * To set an address in I/O memory, use dma_buf_map_set_vaddr_iomem().
+ *
+ * .. code-block:: c
+ *
+ *	dma_buf_map_set_vaddr_iomem(&map. 0xdeadbeaf);
+ *
  * Test if a mapping is valid with either dma_buf_map_is_set() or
  * dma_buf_map_is_null().
  *
@@ -118,6 +124,20 @@  static inline void dma_buf_map_set_vaddr(struct dma_buf_map *map, void *vaddr)
 	map->is_iomem = false;
 }
 
+/**
+ * dma_buf_map_set_vaddr_iomem - Sets a dma-buf mapping structure to an address in I/O memory
+ * @map:		The dma-buf mapping structure
+ * @vaddr_iomem:	An I/O-memory address
+ *
+ * Sets the address and the I/O-memory flag.
+ */
+static inline void dma_buf_map_set_vaddr_iomem(struct dma_buf_map *map,
+					       void __iomem *vaddr_iomem)
+{
+	map->vaddr_iomem = vaddr_iomem;
+	map->is_iomem = true;
+}
+
 /**
  * dma_buf_map_is_equal - Compares two dma-buf mapping structures for equality
  * @lhs:	The dma-buf mapping structure