Patch "drm/vmwgfx: Don't cache framebuffer maps" has been added to the 4.14-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    drm/vmwgfx: Don't cache framebuffer maps

to the 4.14-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     drm-vmwgfx-don-t-cache-framebuffer-maps.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 98648ae6ef6bdcdcb88c46cad963906ab452e96d Mon Sep 17 00:00:00 2001
From: Thomas Hellstrom <thellstrom@vmware.com>
Date: Tue, 9 Jan 2018 15:33:42 +0100
Subject: drm/vmwgfx: Don't cache framebuffer maps

From: Thomas Hellstrom <thellstrom@vmware.com>

commit 98648ae6ef6bdcdcb88c46cad963906ab452e96d upstream.

Buffer objects need to be either pinned or reserved while a map is active,
that's not the case here, so avoid caching the framebuffer map.
This will cause increasing mapping activity mainly when we don't do
page flipping.

This fixes occasional garbage filled screens when the framebuffer has been
evicted after the map.

Since in-kernel mapping of whole buffer objects is error-prone on 32-bit
architectures and also quite inefficient, we will revisit this later.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/gpu/drm/vmwgfx/vmwgfx_kms.c  |    6 -----
 drivers/gpu/drm/vmwgfx/vmwgfx_kms.h  |    2 -
 drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c |   41 ++++++++++-------------------------
 3 files changed, 13 insertions(+), 36 deletions(-)

--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.c
@@ -697,7 +697,6 @@ vmw_du_plane_duplicate_state(struct drm_
 	vps->pinned = 0;
 
 	/* Mapping is managed by prepare_fb/cleanup_fb */
-	memset(&vps->guest_map, 0, sizeof(vps->guest_map));
 	memset(&vps->host_map, 0, sizeof(vps->host_map));
 	vps->cpp = 0;
 
@@ -760,11 +759,6 @@ vmw_du_plane_destroy_state(struct drm_pl
 
 
 	/* Should have been freed by cleanup_fb */
-	if (vps->guest_map.virtual) {
-		DRM_ERROR("Guest mapping not freed\n");
-		ttm_bo_kunmap(&vps->guest_map);
-	}
-
 	if (vps->host_map.virtual) {
 		DRM_ERROR("Host mapping not freed\n");
 		ttm_bo_kunmap(&vps->host_map);
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_kms.h
@@ -175,7 +175,7 @@ struct vmw_plane_state {
 	int pinned;
 
 	/* For CPU Blit */
-	struct ttm_bo_kmap_obj host_map, guest_map;
+	struct ttm_bo_kmap_obj host_map;
 	unsigned int cpp;
 };
 
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_stdu.c
@@ -114,7 +114,7 @@ struct vmw_screen_target_display_unit {
 	bool defined;
 
 	/* For CPU Blit */
-	struct ttm_bo_kmap_obj host_map, guest_map;
+	struct ttm_bo_kmap_obj host_map;
 	unsigned int cpp;
 };
 
@@ -695,7 +695,8 @@ static void vmw_stdu_dmabuf_cpu_commit(s
 	s32 src_pitch, dst_pitch;
 	u8 *src, *dst;
 	bool not_used;
-
+	struct ttm_bo_kmap_obj guest_map;
+	int ret;
 
 	if (!dirty->num_hits)
 		return;
@@ -706,6 +707,13 @@ static void vmw_stdu_dmabuf_cpu_commit(s
 	if (width == 0 || height == 0)
 		return;
 
+	ret = ttm_bo_kmap(&ddirty->buf->base, 0, ddirty->buf->base.num_pages,
+			  &guest_map);
+	if (ret) {
+		DRM_ERROR("Failed mapping framebuffer for blit: %d\n",
+			  ret);
+		goto out_cleanup;
+	}
 
 	/* Assume we are blitting from Host (display_srf) to Guest (dmabuf) */
 	src_pitch = stdu->display_srf->base_size.width * stdu->cpp;
@@ -713,7 +721,7 @@ static void vmw_stdu_dmabuf_cpu_commit(s
 	src += ddirty->top * src_pitch + ddirty->left * stdu->cpp;
 
 	dst_pitch = ddirty->pitch;
-	dst = ttm_kmap_obj_virtual(&stdu->guest_map, &not_used);
+	dst = ttm_kmap_obj_virtual(&guest_map, &not_used);
 	dst += ddirty->fb_top * dst_pitch + ddirty->fb_left * stdu->cpp;
 
 
@@ -772,6 +780,7 @@ static void vmw_stdu_dmabuf_cpu_commit(s
 		vmw_fifo_commit(dev_priv, sizeof(*cmd));
 	}
 
+	ttm_bo_kunmap(&guest_map);
 out_cleanup:
 	ddirty->left = ddirty->top = ddirty->fb_left = ddirty->fb_top = S32_MAX;
 	ddirty->right = ddirty->bottom = S32_MIN;
@@ -1109,9 +1118,6 @@ vmw_stdu_primary_plane_cleanup_fb(struct
 {
 	struct vmw_plane_state *vps = vmw_plane_state_to_vps(old_state);
 
-	if (vps->guest_map.virtual)
-		ttm_bo_kunmap(&vps->guest_map);
-
 	if (vps->host_map.virtual)
 		ttm_bo_kunmap(&vps->host_map);
 
@@ -1277,33 +1283,11 @@ vmw_stdu_primary_plane_prepare_fb(struct
 	 */
 	if (vps->content_fb_type == SEPARATE_DMA &&
 	    !(dev_priv->capabilities & SVGA_CAP_3D)) {
-
-		struct vmw_framebuffer_dmabuf *new_vfbd;
-
-		new_vfbd = vmw_framebuffer_to_vfbd(new_fb);
-
-		ret = ttm_bo_reserve(&new_vfbd->buffer->base, false, false,
-				     NULL);
-		if (ret)
-			goto out_srf_unpin;
-
-		ret = ttm_bo_kmap(&new_vfbd->buffer->base, 0,
-				  new_vfbd->buffer->base.num_pages,
-				  &vps->guest_map);
-
-		ttm_bo_unreserve(&new_vfbd->buffer->base);
-
-		if (ret) {
-			DRM_ERROR("Failed to map content buffer to CPU\n");
-			goto out_srf_unpin;
-		}
-
 		ret = ttm_bo_kmap(&vps->surf->res.backup->base, 0,
 				  vps->surf->res.backup->base.num_pages,
 				  &vps->host_map);
 		if (ret) {
 			DRM_ERROR("Failed to map display buffer to CPU\n");
-			ttm_bo_kunmap(&vps->guest_map);
 			goto out_srf_unpin;
 		}
 
@@ -1350,7 +1334,6 @@ vmw_stdu_primary_plane_atomic_update(str
 	stdu->display_srf = vps->surf;
 	stdu->content_fb_type = vps->content_fb_type;
 	stdu->cpp = vps->cpp;
-	memcpy(&stdu->guest_map, &vps->guest_map, sizeof(vps->guest_map));
 	memcpy(&stdu->host_map, &vps->host_map, sizeof(vps->host_map));
 
 	if (!stdu->defined)


Patches currently in stable-queue which might be from thellstrom@vmware.com are

queue-4.14/drm-vmwgfx-don-t-cache-framebuffer-maps.patch
queue-4.14/drm-vmwgfx-potential-off-by-one-in-vmw_view_add.patch