[PATCH 5.11 068/122] drm/vmwgfx: Make sure we unpin no longer needed buffers

Greg Kroah-Hartman
2021-04-19T13:15:14Z

From: Zack Rusin <zackr@vmware.com>

commit ab4d9913632b1e5ffcf3365783e98718b3c83c7f upstream.

We were not correctly unpinning no longer needed buffers. In particular
vmw_buffer_object, which is internally often pinned on creation wasn't
unpinned on destruction and none of the internal MOB buffers were
unpinned before being put back. Technically this existed for a
long time but commit 57fcd550eb15 ("drm/ttm: Warn on pinning without
holding a reference") introduced a WARN_ON which was filling up the
kernel logs rather quickly.

Quite frankly internal usage of vmw_buffer_object and in general
pinning needs to be refactored in vmwgfx but for now this makes
it work.

Signed-off-by: Zack Rusin <zackr@vmware.com>
Reviewed-by: Martin Krastev <krastevm@vmware.com>
Reviewed-by: Roland Scheidegger <sroland@vmware.com>
Fixes: 57fcd550eb15 ("drm/ttm: Warn on pinning without holding a reference")
Link: https://patchwork.freedesktop.org/patch/414984/?series=86052&rev=1
Cc: Huang Rui <ray.huang@amd.com>
Cc: Christian König <christian.koenig@amd.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Christian Koenig <christian.koenig@amd.com>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/vmwgfx/vmwgfx_drv.h | 2 ++
drivers/gpu/drm/vmwgfx/vmwgfx_mob.c | 4 ++++
2 files changed, 6 insertions(+)

--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -1554,6 +1554,8 @@ static inline void vmw_bo_unreference(st

*buf = NULL;
if (tmp_buf != NULL) {
+ if (tmp_buf->base.pin_count > 0)
+ ttm_bo_unpin(&tmp_buf->base);
ttm_bo_put(&tmp_buf->base);
}
}
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_mob.c
@@ -277,6 +277,7 @@ out_no_setup:
&batch->otables[i]);
}

+ ttm_bo_unpin(batch->otable_bo);
ttm_bo_put(batch->otable_bo);
batch->otable_bo = NULL;
return ret;
@@ -342,6 +343,7 @@ static void vmw_otable_batch_takedown(st
vmw_bo_fence_single(bo, NULL);
ttm_bo_unreserve(bo);

+ ttm_bo_unpin(batch->otable_bo);
ttm_bo_put(batch->otable_bo);
batch->otable_bo = NULL;
}
@@ -528,6 +530,7 @@ static void vmw_mob_pt_setup(struct vmw_
void vmw_mob_destroy(struct vmw_mob *mob)
{
if (mob->pt_bo) {
+ ttm_bo_unpin(mob->pt_bo);
ttm_bo_put(mob->pt_bo);
mob->pt_bo = NULL;
}
@@ -643,6 +646,7 @@ int vmw_mob_bind(struct vmw_private *dev
out_no_cmd_space:
vmw_fifo_resource_dec(dev_priv);
if (pt_set_up) {
+ ttm_bo_unpin(mob->pt_bo);
ttm_bo_put(mob->pt_bo);
mob->pt_bo = NULL;
}