[PATCH v4 06/13] drm/cirrus: Use drm_gem_shmem_vmap_local() in damage handling

[Daniel Vetter]

On Fri, Jan 08, 2021 at 10:43:33AM +0100, Thomas Zimmermann wrote:
> Damage handling in cirrus requires a short-term mapping of the source
> BO. Use drm_gem_shmem_vmap_local().
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann at suse.de>

Hm more possible errors that we don't report to userspace ... Why don't we
vmap/vunmap these in prepare/cleanup_fb? Generally we'd want a long-term
vmap here to make sure this all works nicely.

Since it's nothing new, on this patch:

Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>

> ---
>  drivers/gpu/drm/tiny/cirrus.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/tiny/cirrus.c b/drivers/gpu/drm/tiny/cirrus.c
> index a043e602199e..21cd7056d45f 100644
> --- a/drivers/gpu/drm/tiny/cirrus.c
> +++ b/drivers/gpu/drm/tiny/cirrus.c
> @@ -315,6 +315,7 @@ static int cirrus_fb_blit_rect(struct drm_framebuffer *fb,
>  			       struct drm_rect *rect)
>  {
>  	struct cirrus_device *cirrus = to_cirrus(fb->dev);
> +	struct drm_gem_object *obj = fb->obj[0];
>  	struct dma_buf_map map;
>  	void *vmap;
>  	int idx, ret;
> @@ -323,9 +324,12 @@ static int cirrus_fb_blit_rect(struct drm_framebuffer *fb,
>  	if (!drm_dev_enter(&cirrus->dev, &idx))
>  		goto out;
>  
> -	ret = drm_gem_shmem_vmap(fb->obj[0], &map);
> +	ret = dma_resv_lock(obj->resv, NULL);
>  	if (ret)
>  		goto out_dev_exit;
> +	ret = drm_gem_shmem_vmap_local(fb->obj[0], &map);
> +	if (ret)
> +		goto out_dma_resv_unlock;
>  	vmap = map.vaddr; /* TODO: Use mapping abstraction properly */
>  
>  	if (cirrus->cpp == fb->format->cpp[0])
> @@ -345,9 +349,11 @@ static int cirrus_fb_blit_rect(struct drm_framebuffer *fb,
>  	else
>  		WARN_ON_ONCE("cpp mismatch");
>  
> -	drm_gem_shmem_vunmap(fb->obj[0], &map);
>  	ret = 0;
>  
> +	drm_gem_shmem_vunmap_local(obj, &map);
> +out_dma_resv_unlock:
> +	dma_resv_unlock(obj->resv);
>  out_dev_exit:
>  	drm_dev_exit(idx);
>  out:
> -- 
> 2.29.2
> 

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch