diff mbox series

[v4,05/10] drm/ttm: Add vmap/vunmap to TTM and TTM GEM helpers

Message ID 20201015123806.32416-6-tzimmermann@suse.de
State New, archived
Headers show
Series Support GEM object mappings from I/O memory | expand

Commit Message

Thomas Zimmermann Oct. 15, 2020, 12:38 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.

v4:
	* drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel,
	  Christian)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
---
 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. 15, 2020, 2:08 p.m. UTC | #1
Am 15.10.20 um 14:38 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.
>
> v4:
> 	* drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel,
> 	  Christian)

Bunch of minor comments below, but over all look very solid to me.

>
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> ---
>   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 bdee4df1f3f2..80c42c774c7d 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>
> @@ -526,6 +527,77 @@ 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;
> +		unsigned long size = bo->num_pages << PAGE_SHIFT;

Please use uint64_t here and make sure to cast bo->num_pages before 
shifting.

We have an unit tests of allocating a 8GB BO and that should work on a 
32bit machine as well :)

> +
> +		if (mem->bus.addr)
> +			vaddr_iomem = (void *)(((u8 *)mem->bus.addr));
> +		else if (mem->placement & TTM_PL_FLAG_WC)

I've just nuked the TTM_PL_FLAG_WC flag in drm-misc-next. There is a new 
mem->bus.caching enum as replacement.

> +			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;
> +
> +		BUG_ON(!ttm);

I think we can drop this, populate will just crash badly anyway.

> +
> +		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(mem->placement, PAGE_KERNEL);

The calling convention has changed on drm-misc-next as well, but should 
be trivial to adapt.

Regards,
Christian.

> +		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)
> +{
> +	if (dma_buf_map_is_null(map))
> +		return;
> +
> +	if (map->is_iomem)
> +		iounmap(map->vaddr_iomem);
> +	else
> +		vunmap(map->vaddr);
> +	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
Daniel Vetter Oct. 15, 2020, 4:49 p.m. UTC | #2
On Thu, Oct 15, 2020 at 04:08:13PM +0200, Christian König wrote:
> Am 15.10.20 um 14:38 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.
> > 
> > v4:
> > 	* drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel,
> > 	  Christian)
> 
> Bunch of minor comments below, but over all look very solid to me.

Yeah I think just duplicating the ttm bo map stuff for vmap is indeed the
cleanest. And then we can maybe push the combinatorial monster into
vmwgfx, which I think is the only user after this series. Or perhaps a
dedicated set of helpers to map an invidual page (again using the
dma_buf_map stuff).

I'll let Christian with the details, but at a high level this is
definitely

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

Thanks a lot for doing all this.
-Daniel

> 
> > 
> > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> > ---
> >   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 bdee4df1f3f2..80c42c774c7d 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>
> > @@ -526,6 +527,77 @@ 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;
> > +		unsigned long size = bo->num_pages << PAGE_SHIFT;
> 
> Please use uint64_t here and make sure to cast bo->num_pages before
> shifting.
> 
> We have an unit tests of allocating a 8GB BO and that should work on a 32bit
> machine as well :)
> 
> > +
> > +		if (mem->bus.addr)
> > +			vaddr_iomem = (void *)(((u8 *)mem->bus.addr));
> > +		else if (mem->placement & TTM_PL_FLAG_WC)
> 
> I've just nuked the TTM_PL_FLAG_WC flag in drm-misc-next. There is a new
> mem->bus.caching enum as replacement.
> 
> > +			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;
> > +
> > +		BUG_ON(!ttm);
> 
> I think we can drop this, populate will just crash badly anyway.
> 
> > +
> > +		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(mem->placement, PAGE_KERNEL);
> 
> The calling convention has changed on drm-misc-next as well, but should be
> trivial to adapt.
> 
> Regards,
> Christian.
> 
> > +		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)
> > +{
> > +	if (dma_buf_map_is_null(map))
> > +		return;
> > +
> > +	if (map->is_iomem)
> > +		iounmap(map->vaddr_iomem);
> > +	else
> > +		vunmap(map->vaddr);
> > +	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
>
Thomas Zimmermann Oct. 15, 2020, 5:52 p.m. UTC | #3
Hi

On Thu, 15 Oct 2020 18:49:09 +0200 Daniel Vetter <daniel@ffwll.ch> wrote:

> On Thu, Oct 15, 2020 at 04:08:13PM +0200, Christian König wrote:
> > Am 15.10.20 um 14:38 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.
> > > 
> > > v4:
> > > 	* drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers
> > > (Daniel, Christian)
> > 
> > Bunch of minor comments below, but over all look very solid to me.
> 
> Yeah I think just duplicating the ttm bo map stuff for vmap is indeed the
> cleanest. And then we can maybe push the combinatorial monster into
> vmwgfx, which I think is the only user after this series. Or perhaps a
> dedicated set of helpers to map an invidual page (again using the
> dma_buf_map stuff).

From a quick look, I'd say it should be possible to have the same interface
for kmap/kunmap as for vmap/vunmap (i.e., parameters are bo and dma-buf-map).
All mapping state can be deduced from this. And struct ttm_bo_kmap_obj can be
killed off entirely.

Best regards
Thomas

> 
> I'll let Christian with the details, but at a high level this is
> definitely
> 
> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> 
> Thanks a lot for doing all this.
> -Daniel
> 
> > 
> > > 
> > > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> > > ---
> > >   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 bdee4df1f3f2..80c42c774c7d
> > > 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>
> > > @@ -526,6 +527,77 @@ 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;
> > > +		unsigned long size = bo->num_pages << PAGE_SHIFT;
> > 
> > Please use uint64_t here and make sure to cast bo->num_pages before
> > shifting.
> > 
> > We have an unit tests of allocating a 8GB BO and that should work on a
> > 32bit machine as well :)
> > 
> > > +
> > > +		if (mem->bus.addr)
> > > +			vaddr_iomem = (void *)(((u8 *)mem->bus.addr));
> > > +		else if (mem->placement & TTM_PL_FLAG_WC)
> > 
> > I've just nuked the TTM_PL_FLAG_WC flag in drm-misc-next. There is a new
> > mem->bus.caching enum as replacement.
> > 
> > > +			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;
> > > +
> > > +		BUG_ON(!ttm);
> > 
> > I think we can drop this, populate will just crash badly anyway.
> > 
> > > +
> > > +		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(mem->placement, PAGE_KERNEL);
> > 
> > The calling convention has changed on drm-misc-next as well, but should be
> > trivial to adapt.
> > 
> > Regards,
> > Christian.
> > 
> > > +		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) +{
> > > +	if (dma_buf_map_is_null(map))
> > > +		return;
> > > +
> > > +	if (map->is_iomem)
> > > +		iounmap(map->vaddr_iomem);
> > > +	else
> > > +		vunmap(map->vaddr);
> > > +	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
> > 
>
Thomas Zimmermann Oct. 15, 2020, 5:56 p.m. UTC | #4
Hi

On Thu, 15 Oct 2020 16:08:13 +0200 Christian König <christian.koenig@amd.com>
wrote:

> Am 15.10.20 um 14:38 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.
> >
> > v4:
> > 	* drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel,
> > 	  Christian)
> 
> Bunch of minor comments below, but over all look very solid to me.
> 
> >
> > Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> > ---
> >   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 bdee4df1f3f2..80c42c774c7d
> > 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>
> > @@ -526,6 +527,77 @@ 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;
> > +		unsigned long size = bo->num_pages << PAGE_SHIFT;
> 
> Please use uint64_t here and make sure to cast bo->num_pages before 
> shifting.
> 
> We have an unit tests of allocating a 8GB BO and that should work on a 
> 32bit machine as well :)
> 
> > +
> > +		if (mem->bus.addr)
> > +			vaddr_iomem = (void *)(((u8 *)mem->bus.addr));
> > +		else if (mem->placement & TTM_PL_FLAG_WC)
> 
> I've just nuked the TTM_PL_FLAG_WC flag in drm-misc-next. There is a new 
> mem->bus.caching enum as replacement.
> 
> > +			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;
> > +
> > +		BUG_ON(!ttm);
> 
> I think we can drop this, populate will just crash badly anyway.
> 
> > +
> > +		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(mem->placement, PAGE_KERNEL);
> 
> The calling convention has changed on drm-misc-next as well, but should 
> be trivial to adapt.

Thanks for quickly reviewing these patches. My drm-tip seems out of date
(last Sunday). TTM is moving fast these days and I still have to get used to
that. :)

Best regards
Thomas

> 
> Regards,
> Christian.
> 
> > +		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)
> > +{
> > +	if (dma_buf_map_is_null(map))
> > +		return;
> > +
> > +	if (map->is_iomem)
> > +		iounmap(map->vaddr_iomem);
> > +	else
> > +		vunmap(map->vaddr);
> > +	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
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Christian König Oct. 16, 2020, 9:41 a.m. UTC | #5
Am 15.10.20 um 19:52 schrieb Thomas Zimmermann:
> Hi
>
> On Thu, 15 Oct 2020 18:49:09 +0200 Daniel Vetter <daniel@ffwll.ch> wrote:
>
>> On Thu, Oct 15, 2020 at 04:08:13PM +0200, Christian König wrote:
>>> Am 15.10.20 um 14:38 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.
>>>>
>>>> v4:
>>>> 	* drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers
>>>> (Daniel, Christian)
>>> Bunch of minor comments below, but over all look very solid to me.
>> Yeah I think just duplicating the ttm bo map stuff for vmap is indeed the
>> cleanest. And then we can maybe push the combinatorial monster into
>> vmwgfx, which I think is the only user after this series. Or perhaps a
>> dedicated set of helpers to map an invidual page (again using the
>> dma_buf_map stuff).
>  From a quick look, I'd say it should be possible to have the same interface
> for kmap/kunmap as for vmap/vunmap (i.e., parameters are bo and dma-buf-map).
> All mapping state can be deduced from this. And struct ttm_bo_kmap_obj can be
> killed off entirely.

Yes, that would be rather nice to have.

Thanks,
Christian.

>
> Best regards
> Thomas
>
>> I'll let Christian with the details, but at a high level this is
>> definitely
>>
>> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
>>
>> Thanks a lot for doing all this.
>> -Daniel
>>
>>>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>>>> ---
>>>>    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 bdee4df1f3f2..80c42c774c7d
>>>> 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>
>>>> @@ -526,6 +527,77 @@ 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;
>>>> +		unsigned long size = bo->num_pages << PAGE_SHIFT;
>>> Please use uint64_t here and make sure to cast bo->num_pages before
>>> shifting.
>>>
>>> We have an unit tests of allocating a 8GB BO and that should work on a
>>> 32bit machine as well :)
>>>
>>>> +
>>>> +		if (mem->bus.addr)
>>>> +			vaddr_iomem = (void *)(((u8 *)mem->bus.addr));
>>>> +		else if (mem->placement & TTM_PL_FLAG_WC)
>>> I've just nuked the TTM_PL_FLAG_WC flag in drm-misc-next. There is a new
>>> mem->bus.caching enum as replacement.
>>>
>>>> +			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;
>>>> +
>>>> +		BUG_ON(!ttm);
>>> I think we can drop this, populate will just crash badly anyway.
>>>
>>>> +
>>>> +		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(mem->placement, PAGE_KERNEL);
>>> The calling convention has changed on drm-misc-next as well, but should be
>>> trivial to adapt.
>>>
>>> Regards,
>>> Christian.
>>>
>>>> +		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) +{
>>>> +	if (dma_buf_map_is_null(map))
>>>> +		return;
>>>> +
>>>> +	if (map->is_iomem)
>>>> +		iounmap(map->vaddr_iomem);
>>>> +	else
>>>> +		vunmap(map->vaddr);
>>>> +	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
>
>
Thomas Zimmermann Oct. 19, 2020, 9:08 a.m. UTC | #6
Hi Christian

On 15.10.20 16:08, Christian König wrote:
> Am 15.10.20 um 14:38 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.
>>
>> v4:
>>     * drop ttm_kmap_obj_to_dma_buf() in favor of vmap helpers (Daniel,
>>       Christian)
> 
> Bunch of minor comments below, but over all look very solid to me.
> 
>>
>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>> ---
>>   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 bdee4df1f3f2..80c42c774c7d 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>
>> @@ -526,6 +527,77 @@ 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;
>> +        unsigned long size = bo->num_pages << PAGE_SHIFT;
> 
> Please use uint64_t here and make sure to cast bo->num_pages before
> shifting.

I thought the rule of thumb is to use u64 in source code. Yet TTM only
uses uint*_t types. Is there anything special about TTM?

> 
> We have an unit tests of allocating a 8GB BO and that should work on a
> 32bit machine as well :)
> 
>> +
>> +        if (mem->bus.addr)
>> +            vaddr_iomem = (void *)(((u8 *)mem->bus.addr));

I after reading the patch again, I realized that this is the
'ttm_bo_map_premapped' case and it's missing from _vunmap(). I see two
options here: ignore this case in _vunmap(), or do an ioremap()
unconditionally. Which one is preferable?

Best regards
Thomas

>> +        else if (mem->placement & TTM_PL_FLAG_WC)
> 
> I've just nuked the TTM_PL_FLAG_WC flag in drm-misc-next. There is a new
> mem->bus.caching enum as replacement.
> 
>> +            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;
>> +
>> +        BUG_ON(!ttm);
> 
> I think we can drop this, populate will just crash badly anyway.
> 
>> +
>> +        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(mem->placement, PAGE_KERNEL);
> 
> The calling convention has changed on drm-misc-next as well, but should
> be trivial to adapt.
> 
> Regards,
> Christian.
> 
>> +        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)
>> +{
>> +    if (dma_buf_map_is_null(map))
>> +        return;
>> +
>> +    if (map->is_iomem)
>> +        iounmap(map->vaddr_iomem);
>> +    else
>> +        vunmap(map->vaddr);
>> +    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
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel
Christian König Oct. 19, 2020, 9:45 a.m. UTC | #7
Hi Thomas,

[SNIP]
>>>    +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;
>>> +        unsigned long size = bo->num_pages << PAGE_SHIFT;
>> Please use uint64_t here and make sure to cast bo->num_pages before
>> shifting.
> I thought the rule of thumb is to use u64 in source code. Yet TTM only
> uses uint*_t types. Is there anything special about TTM?

My last status is that you can use both and my personal preference is to 
use the uint*_t types because they are part of a higher level standard.

>> We have an unit tests of allocating a 8GB BO and that should work on a
>> 32bit machine as well :)
>>
>>> +
>>> +        if (mem->bus.addr)
>>> +            vaddr_iomem = (void *)(((u8 *)mem->bus.addr));
> I after reading the patch again, I realized that this is the
> 'ttm_bo_map_premapped' case and it's missing from _vunmap(). I see two
> options here: ignore this case in _vunmap(), or do an ioremap()
> unconditionally. Which one is preferable?

ioremap would be very very bad, so we should just do nothing.

Thanks,
Christian.

>
> Best regards
> Thomas
>
>>> +        else if (mem->placement & TTM_PL_FLAG_WC)
>> I've just nuked the TTM_PL_FLAG_WC flag in drm-misc-next. There is a new
>> mem->bus.caching enum as replacement.
>>
>>> +            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;
>>> +
>>> +        BUG_ON(!ttm);
>> I think we can drop this, populate will just crash badly anyway.
>>
>>> +
>>> +        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(mem->placement, PAGE_KERNEL);
>> The calling convention has changed on drm-misc-next as well, but should
>> be trivial to adapt.
>>
>> Regards,
>> Christian.
>>
>>> +        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)
>>> +{
>>> +    if (dma_buf_map_is_null(map))
>>> +        return;
>>> +
>>> +    if (map->is_iomem)
>>> +        iounmap(map->vaddr_iomem);
>>> +    else
>>> +        vunmap(map->vaddr);
>>> +    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
>> _______________________________________________
>> dri-devel mailing list
>> dri-devel@lists.freedesktop.org
>> https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&amp;data=04%7C01%7Cchristian.koenig%40amd.com%7C07bc68af3c6440b5be8d08d8740e9b32%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637386953433558595%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=RlGCmjzyZERvqfnl4kA1bEHez5bkLf3F9OlKi2ybDAM%3D&amp;reserved=0
Daniel Vetter Oct. 19, 2020, 3:46 p.m. UTC | #8
On Mon, Oct 19, 2020 at 11:45:05AM +0200, Christian König wrote:
> Hi Thomas,
> 
> [SNIP]
> > > >    +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;
> > > > +        unsigned long size = bo->num_pages << PAGE_SHIFT;
> > > Please use uint64_t here and make sure to cast bo->num_pages before
> > > shifting.
> > I thought the rule of thumb is to use u64 in source code. Yet TTM only
> > uses uint*_t types. Is there anything special about TTM?
> 
> My last status is that you can use both and my personal preference is to use
> the uint*_t types because they are part of a higher level standard.

Yeah the only hard rule is that in uapi headers you need to use the __u64
and similar typedefs, to avoid cluttering the namespace for unrelated
stuff in userspace.

In the kernel c99 types are perfectly fine, and I think slowly on the
rise.
-Daniel

> 
> > > We have an unit tests of allocating a 8GB BO and that should work on a
> > > 32bit machine as well :)
> > > 
> > > > +
> > > > +        if (mem->bus.addr)
> > > > +            vaddr_iomem = (void *)(((u8 *)mem->bus.addr));
> > I after reading the patch again, I realized that this is the
> > 'ttm_bo_map_premapped' case and it's missing from _vunmap(). I see two
> > options here: ignore this case in _vunmap(), or do an ioremap()
> > unconditionally. Which one is preferable?
> 
> ioremap would be very very bad, so we should just do nothing.
> 
> Thanks,
> Christian.
> 
> > 
> > Best regards
> > Thomas
> > 
> > > > +        else if (mem->placement & TTM_PL_FLAG_WC)
> > > I've just nuked the TTM_PL_FLAG_WC flag in drm-misc-next. There is a new
> > > mem->bus.caching enum as replacement.
> > > 
> > > > +            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;
> > > > +
> > > > +        BUG_ON(!ttm);
> > > I think we can drop this, populate will just crash badly anyway.
> > > 
> > > > +
> > > > +        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(mem->placement, PAGE_KERNEL);
> > > The calling convention has changed on drm-misc-next as well, but should
> > > be trivial to adapt.
> > > 
> > > Regards,
> > > Christian.
> > > 
> > > > +        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)
> > > > +{
> > > > +    if (dma_buf_map_is_null(map))
> > > > +        return;
> > > > +
> > > > +    if (map->is_iomem)
> > > > +        iounmap(map->vaddr_iomem);
> > > > +    else
> > > > +        vunmap(map->vaddr);
> > > > +    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
> > > _______________________________________________
> > > dri-devel mailing list
> > > dri-devel@lists.freedesktop.org
> > > https://nam11.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.freedesktop.org%2Fmailman%2Flistinfo%2Fdri-devel&amp;data=04%7C01%7Cchristian.koenig%40amd.com%7C07bc68af3c6440b5be8d08d8740e9b32%7C3dd8961fe4884e608e11a82d994e183d%7C0%7C0%7C637386953433558595%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C1000&amp;sdata=RlGCmjzyZERvqfnl4kA1bEHez5bkLf3F9OlKi2ybDAM%3D&amp;reserved=0
>
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 bdee4df1f3f2..80c42c774c7d 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>
@@ -526,6 +527,77 @@  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;
+		unsigned long size = bo->num_pages << PAGE_SHIFT;
+
+		if (mem->bus.addr)
+			vaddr_iomem = (void *)(((u8 *)mem->bus.addr));
+		else if (mem->placement & TTM_PL_FLAG_WC)
+			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;
+
+		BUG_ON(!ttm);
+
+		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(mem->placement, 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)
+{
+	if (dma_buf_map_is_null(map))
+		return;
+
+	if (map->is_iomem)
+		iounmap(map->vaddr_iomem);
+	else
+		vunmap(map->vaddr);
+	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