Re: [PATCH V1 10/10] drm: Remove drm specific kmap_atomic code

[Christian König <christian.koenig@xxxxxxx>]

Am 30.04.20 um 22:38 schrieb ira.weiny@xxxxxxxxx:
> From: Ira Weiny <ira.weiny@xxxxxxxxx>
>
> kmap_atomic_prot() is now exported by all architectures.  Use this
> function rather than open coding a driver specific kmap_atomic.
>
> Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>

Ah, yes looking into this once more this was on my TODO list for quite a 
while as well.

Patch is Reviewed-by: Christian König <christian.koenig@xxxxxxx>, feel 
free to push it upstream through whatever channel you like or ping me if 
I should pick it up into drm-misc-next.

Regards,
Christian.

> ---
>   drivers/gpu/drm/ttm/ttm_bo_util.c    | 56 ++--------------------------
>   drivers/gpu/drm/vmwgfx/vmwgfx_blit.c | 16 ++++----
>   include/drm/ttm/ttm_bo_api.h         |  4 --
>   3 files changed, 12 insertions(+), 64 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
> index 52d2b71f1588..f09b096ba4fd 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
> @@ -257,54 +257,6 @@ static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
>   	return 0;
>   }
>   
> -#ifdef CONFIG_X86
> -#define __ttm_kmap_atomic_prot(__page, __prot) kmap_atomic_prot(__page, __prot)
> -#define __ttm_kunmap_atomic(__addr) kunmap_atomic(__addr)
> -#else
> -#define __ttm_kmap_atomic_prot(__page, __prot) vmap(&__page, 1, 0,  __prot)
> -#define __ttm_kunmap_atomic(__addr) vunmap(__addr)
> -#endif
> -
> -
> -/**
> - * ttm_kmap_atomic_prot - Efficient kernel map of a single page with
> - * specified page protection.
> - *
> - * @page: The page to map.
> - * @prot: The page protection.
> - *
> - * This function maps a TTM page using the kmap_atomic api if available,
> - * otherwise falls back to vmap. The user must make sure that the
> - * specified page does not have an aliased mapping with a different caching
> - * policy unless the architecture explicitly allows it. Also mapping and
> - * unmapping using this api must be correctly nested. Unmapping should
> - * occur in the reverse order of mapping.
> - */
> -void *ttm_kmap_atomic_prot(struct page *page, pgprot_t prot)
> -{
> -	if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
> -		return kmap_atomic(page);
> -	else
> -		return __ttm_kmap_atomic_prot(page, prot);
> -}
> -EXPORT_SYMBOL(ttm_kmap_atomic_prot);
> -
> -/**
> - * ttm_kunmap_atomic_prot - Unmap a page that was mapped using
> - * ttm_kmap_atomic_prot.
> - *
> - * @addr: The virtual address from the map.
> - * @prot: The page protection.
> - */
> -void ttm_kunmap_atomic_prot(void *addr, pgprot_t prot)
> -{
> -	if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
> -		kunmap_atomic(addr);
> -	else
> -		__ttm_kunmap_atomic(addr);
> -}
> -EXPORT_SYMBOL(ttm_kunmap_atomic_prot);
> -
>   static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
>   				unsigned long page,
>   				pgprot_t prot)
> @@ -316,13 +268,13 @@ static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
>   		return -ENOMEM;
>   
>   	src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
> -	dst = ttm_kmap_atomic_prot(d, prot);
> +	dst = kmap_atomic_prot(d, prot);
>   	if (!dst)
>   		return -ENOMEM;
>   
>   	memcpy_fromio(dst, src, PAGE_SIZE);
>   
> -	ttm_kunmap_atomic_prot(dst, prot);
> +	kunmap_atomic(dst);
>   
>   	return 0;
>   }
> @@ -338,13 +290,13 @@ static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
>   		return -ENOMEM;
>   
>   	dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
> -	src = ttm_kmap_atomic_prot(s, prot);
> +	src = kmap_atomic_prot(s, prot);
>   	if (!src)
>   		return -ENOMEM;
>   
>   	memcpy_toio(dst, src, PAGE_SIZE);
>   
> -	ttm_kunmap_atomic_prot(src, prot);
> +	kunmap_atomic(src);
>   
>   	return 0;
>   }
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c b/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
> index bb46ca0c458f..94d456a1d1a9 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
> @@ -374,12 +374,12 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
>   		copy_size = min_t(u32, copy_size, PAGE_SIZE - src_page_offset);
>   
>   		if (unmap_src) {
> -			ttm_kunmap_atomic_prot(d->src_addr, d->src_prot);
> +			kunmap_atomic(d->src_addr);
>   			d->src_addr = NULL;
>   		}
>   
>   		if (unmap_dst) {
> -			ttm_kunmap_atomic_prot(d->dst_addr, d->dst_prot);
> +			kunmap_atomic(d->dst_addr);
>   			d->dst_addr = NULL;
>   		}
>   
> @@ -388,8 +388,8 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
>   				return -EINVAL;
>   
>   			d->dst_addr =
> -				ttm_kmap_atomic_prot(d->dst_pages[dst_page],
> -						     d->dst_prot);
> +				kmap_atomic_prot(d->dst_pages[dst_page],
> +						 d->dst_prot);
>   			if (!d->dst_addr)
>   				return -ENOMEM;
>   
> @@ -401,8 +401,8 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
>   				return -EINVAL;
>   
>   			d->src_addr =
> -				ttm_kmap_atomic_prot(d->src_pages[src_page],
> -						     d->src_prot);
> +				kmap_atomic_prot(d->src_pages[src_page],
> +						 d->src_prot);
>   			if (!d->src_addr)
>   				return -ENOMEM;
>   
> @@ -499,9 +499,9 @@ int vmw_bo_cpu_blit(struct ttm_buffer_object *dst,
>   	}
>   out:
>   	if (d.src_addr)
> -		ttm_kunmap_atomic_prot(d.src_addr, d.src_prot);
> +		kunmap_atomic(d.src_addr);
>   	if (d.dst_addr)
> -		ttm_kunmap_atomic_prot(d.dst_addr, d.dst_prot);
> +		kunmap_atomic(d.dst_addr);
>   
>   	return ret;
>   }
> diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
> index 0a9d042e075a..de1ccdcd5703 100644
> --- a/include/drm/ttm/ttm_bo_api.h
> +++ b/include/drm/ttm/ttm_bo_api.h
> @@ -668,10 +668,6 @@ int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
>   int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
>   		struct ttm_bo_device *bdev);
>   
> -void *ttm_kmap_atomic_prot(struct page *page, pgprot_t prot);
> -
> -void ttm_kunmap_atomic_prot(void *addr, pgprot_t prot);
> -
>   /**
>    * ttm_bo_io
>    *