2023-05-09 16:41:38

by Rob Clark

[permalink] [raw]
Subject: [PATCH 2/2] drm/msm: Be more shouty if per-process pgtables aren't working

From: Rob Clark <[email protected]>

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 <[email protected]>
---
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 418e1e06cdde..9b19124c9bd0 100644
--- a/drivers/gpu/drm/msm/msm_iommu.c
+++ b/drivers/gpu/drm/msm/msm_iommu.c
@@ -227,21 +227,26 @@ struct msm_mmu *msm_iommu_pagetable_create(struct msm_mmu *parent)
struct adreno_smmu_priv *adreno_smmu = dev_get_drvdata(parent->dev);
struct msm_iommu *iommu = to_msm_iommu(parent);
struct msm_iommu_pagetable *pagetable;
const struct io_pgtable_cfg *ttbr1_cfg = NULL;
struct io_pgtable_cfg ttbr0_cfg;
int ret;

/* 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);
if (!pagetable)
return ERR_PTR(-ENOMEM);

msm_mmu_init(&pagetable->base, parent->dev, &pagetable_funcs,
MSM_MMU_IOMMU_PAGETABLE);

/* Clone the TTBR1 cfg as starting point for TTBR0 cfg: */
--
2.40.1