[PATCH AUTOSEL 5.10 29/31] drm/msm: Be more shouty if per-process pgtables aren't working

Sasha Levin
2023-05-25T18:52:06Z

From: Rob Clark <robdclark@chromium.org>

[ Upstream commit 5c054db54c43a5fcb5cc81012361f5e3fac37637 ]

Otherwise it is not always obvious if a dt or iommu change is causing us
to fall back to global pgtable.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Patchwork: https://patchwork.freedesktop.org/patch/537359/
Link: https://lore.kernel.org/r/20230516222039.907690-2-robdclark@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/msm/msm_iommu.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/msm_iommu.c b/drivers/gpu/drm/msm/msm_iommu.c
index ecab6287c1c39..b81390d6ebd38 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -155,7 +155,12 @@ struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent)
/* Get the pagetable configuration from the domain */
if (adreno_smmu->cookie)
ttbr1_cfg = adreno_smmu->get_ttbr1_cfg(adreno_smmu->cookie);
- if (!ttbr1_cfg)
+
+ /*
+ * If you hit this WARN_ONCE() you are probably missing an entry in
+ * qcom_smmu_impl_of_match[] in arm-smmu-qcom.c
+ */
+ if (WARN_ONCE(!ttbr1_cfg, "No per-process page tables"))
return ERR_PTR(-ENODEV);

pagetable = kzalloc(sizeof(*pagetable), GFP_KERNEL);
--
2.39.2