[PATCH v2] drm/amdgpu: Check BO's requested pinning domains against its preferred_domains

[sunpeng.li at amd.com]

From: Leo Li <sunpeng.li at amd.com>

When pinning a buffer, we should check to see if there are any
additional restrictions imposed by bo->preferred_domains. This will
prevent the BO from being moved to an invalid domain when pinning.

For example, this can happen if the user requests to create a BO in GTT
domain for display scanout. amdgpu_dm will allow pinning to either VRAM
or GTT domains, since DCN can scanout from either or. However, in
amdgpu_bo_pin_restricted(), pinning to VRAM is preferred if there is
adequate carveout. This can lead to pinning to VRAM despite the user
requesting GTT placement for the BO.

v2: Allow the kernel to override the domain, which can happen when
    exporting a BO to a V4L camera (for example).

Signed-off-by: Leo Li <sunpeng.li at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_object.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 8a7b0f6162da..bbd3b8b14cfb 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -883,6 +883,10 @@ int amdgpu_bo_pin_restricted(struct amdgpu_bo *bo, u32 domain,
 	if (WARN_ON_ONCE(min_offset > max_offset))
 		return -EINVAL;
 
+	/* Check domain to be pinned to against preferred domains */
+	if (bo->preferred_domains & domain)
+		domain = bo->preferred_domains & domain;
+
 	/* A shared bo cannot be migrated to VRAM */
 	if (bo->tbo.base.import_attach) {
 		if (domain & AMDGPU_GEM_DOMAIN_GTT)
-- 
2.37.0