Re: [PATCH 5/7] drm/vmwgfx: Cleanup the vmw bo usage in the cursor paths

From: "Martin Krastev (VMware)" <martinkrastev768@gmail.com>
To: Zack Rusin <zackr@vmware.com>, dri-devel@lists.freedesktop.org
Cc: krastevm@vmware.com, mombasawalam@vmware.com, banackm@vmware.com
Subject: Re: [PATCH 5/7] drm/vmwgfx: Cleanup the vmw bo usage in the cursor paths
Date: Fri, 27 Jan 2023 20:57:34 +0200	[thread overview]
Message-ID: <d0cf6e3a-e60b-c675-447f-418d99e86a9a@gmail.com> (raw)
In-Reply-To: <20230126173813.602748-6-zack@kde.org>

From: Martin Krastev <krastevm@vmware.com>

Ah, good!
Reviewed-by: Martin Krastev <krastevm@vmware.com>

Regards,
Martin

On 26.01.23 г. 19:38 ч., Zack Rusin wrote:
> From: Zack Rusin <zackr@vmware.com>
>
> Base mapped count is useless because the ttm unmap functions handle
> null maps just fine so completely remove all the code related to it.
> Rename dummy to is_iomem because that's what it is even if we're not
> activelly using it. Makes the code easier to read.
>
> Signed-off-by: Zack Rusin <zackr@vmware.com>
> ---
>   drivers/gpu/drm/vmwgfx/vmwgfx_bo.h  |  4 ----
>   drivers/gpu/drm/vmwgfx/vmwgfx_kms.c | 28 +++++++++-------------------
>   2 files changed, 9 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h
> index db85609ec01c..4dcf37235cb0 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.h
> @@ -44,7 +44,6 @@ struct vmw_resource;
>    * struct vmw_bo - TTM buffer object with vmwgfx additions
>    * @base: The TTM buffer object
>    * @res_tree: RB tree of resources using this buffer object as a backing MOB
> - * @base_mapped_count: ttm BO mapping count; used by KMS atomic helpers.
>    * @cpu_writers: Number of synccpu write grabs. Protected by reservation when
>    * increased. May be decreased without reservation.
>    * @dx_query_ctx: DX context if this buffer object is used as a DX query MOB
> @@ -55,8 +54,6 @@ struct vmw_resource;
>   struct vmw_bo {
>   	struct ttm_buffer_object base;
>   	struct rb_root res_tree;
> -	/* For KMS atomic helpers: ttm bo mapping count */
> -	atomic_t base_mapped_count;
>   
>   	atomic_t cpu_writers;
>   	/* Not ref-counted.  Protected by binding_mutex */
> @@ -67,7 +64,6 @@ struct vmw_bo {
>   	struct vmw_bo_dirty *dirty;
>   };
>   
> -
>   int vmw_bo_create_kernel(struct vmw_private *dev_priv,
>   			 unsigned long size,
>   			 struct ttm_placement *placement,
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> index 6780391c57ea..e83286e08837 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
> @@ -153,9 +153,9 @@ static void vmw_cursor_update_mob(struct vmw_private *dev_priv,
>   	SVGAGBCursorHeader *header;
>   	SVGAGBAlphaCursorHeader *alpha_header;
>   	const u32 image_size = width * height * sizeof(*image);
> -	bool dummy;
> +	bool is_iomem;
>   
> -	header = ttm_kmap_obj_virtual(&vps->cursor.map, &dummy);
> +	header = ttm_kmap_obj_virtual(&vps->cursor.map, &is_iomem);
>   	alpha_header = &header->header.alphaHeader;
>   
>   	memset(header, 0, sizeof(*header));
> @@ -185,13 +185,13 @@ static u32 vmw_du_cursor_mob_size(u32 w, u32 h)
>    */
>   static u32 *vmw_du_cursor_plane_acquire_image(struct vmw_plane_state *vps)
>   {
> -	bool dummy;
> +	bool is_iomem;
>   	if (vps->surf) {
>   		if (vps->surf_mapped)
>   			return vmw_bo_map_and_cache(vps->surf->res.backup);
>   		return vps->surf->snooper.image;
>   	} else if (vps->bo)
> -		return ttm_kmap_obj_virtual(&vps->bo->map, &dummy);
> +		return ttm_kmap_obj_virtual(&vps->bo->map, &is_iomem);
>   	return NULL;
>   }
>   
> @@ -364,7 +364,7 @@ void vmw_kms_cursor_snoop(struct vmw_surface *srf,
>   	SVGA3dCopyBox *box;
>   	unsigned box_count;
>   	void *virtual;
> -	bool dummy;
> +	bool is_iomem;
>   	struct vmw_dma_cmd {
>   		SVGA3dCmdHeader header;
>   		SVGA3dCmdSurfaceDMA dma;
> @@ -424,7 +424,7 @@ void vmw_kms_cursor_snoop(struct vmw_surface *srf,
>   	if (unlikely(ret != 0))
>   		goto err_unreserve;
>   
> -	virtual = ttm_kmap_obj_virtual(&map, &dummy);
> +	virtual = ttm_kmap_obj_virtual(&map, &is_iomem);
>   
>   	if (box->w == VMW_CURSOR_SNOOP_WIDTH && cmd->dma.guest.pitch == image_pitch) {
>   		memcpy(srf->snooper.image, virtual,
> @@ -658,19 +658,18 @@ vmw_du_cursor_plane_cleanup_fb(struct drm_plane *plane,
>   {
>   	struct vmw_cursor_plane *vcp = vmw_plane_to_vcp(plane);
>   	struct vmw_plane_state *vps = vmw_plane_state_to_vps(old_state);
> -	bool dummy;
> +	bool is_iomem;
>   
>   	if (vps->surf_mapped) {
>   		vmw_bo_unmap(vps->surf->res.backup);
>   		vps->surf_mapped = false;
>   	}
>   
> -	if (vps->bo && ttm_kmap_obj_virtual(&vps->bo->map, &dummy)) {
> +	if (vps->bo && ttm_kmap_obj_virtual(&vps->bo->map, &is_iomem)) {
>   		const int ret = ttm_bo_reserve(&vps->bo->base, true, false, NULL);
>   
>   		if (likely(ret == 0)) {
> -			if (atomic_read(&vps->bo->base_mapped_count) == 0)
> -			    ttm_bo_kunmap(&vps->bo->map);
> +			ttm_bo_kunmap(&vps->bo->map);
>   			ttm_bo_unreserve(&vps->bo->base);
>   		}
>   	}
> @@ -744,9 +743,6 @@ vmw_du_cursor_plane_prepare_fb(struct drm_plane *plane,
>   
>   		ret = ttm_bo_kmap(&vps->bo->base, 0, PFN_UP(size), &vps->bo->map);
>   
> -		if (likely(ret == 0))
> -			atomic_inc(&vps->bo->base_mapped_count);
> -
>   		ttm_bo_unreserve(&vps->bo->base);
>   
>   		if (unlikely(ret != 0))
> @@ -786,7 +782,6 @@ vmw_du_cursor_plane_atomic_update(struct drm_plane *plane,
>   	struct vmw_plane_state *vps = vmw_plane_state_to_vps(new_state);
>   	struct vmw_plane_state *old_vps = vmw_plane_state_to_vps(old_state);
>   	s32 hotspot_x, hotspot_y;
> -	bool dummy;
>   
>   	hotspot_x = du->hotspot_x;
>   	hotspot_y = du->hotspot_y;
> @@ -828,11 +823,6 @@ vmw_du_cursor_plane_atomic_update(struct drm_plane *plane,
>   						hotspot_x, hotspot_y);
>   	}
>   
> -	if (vps->bo) {
> -		if (ttm_kmap_obj_virtual(&vps->bo->map, &dummy))
> -			atomic_dec(&vps->bo->base_mapped_count);
> -	}
> -
>   	du->cursor_x = new_state->crtc_x + du->set_gui_x;
>   	du->cursor_y = new_state->crtc_y + du->set_gui_y;
>   