Re: [PATCH] drm/msm: Only enable A6xx LLCC code on A6xx

From: Sai Prakash Ranjan
Date: Wed Jan 06 2021 - 23:51:18 EST


On 2021-01-05 01:00, Konrad Dybcio wrote:
Using this code on A5xx (and probably older too) causes a
smmu bug.

Fixes: 474dadb8b0d5 ("drm/msm/a6xx: Add support for using system cache(LLC)")
Signed-off-by: Konrad Dybcio <konrad.dybcio@xxxxxxxxxxxxxx>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>
---

Reviewed-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>

drivers/gpu/drm/msm/adreno/adreno_gpu.c | 21 ++++++++++++---------
drivers/gpu/drm/msm/adreno/adreno_gpu.h | 5 +++++
2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index 6cf9975e951e..f09175698827 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -191,8 +191,6 @@ adreno_iommu_create_address_space(struct msm_gpu *gpu,
struct platform_device *pdev)
{
struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
- struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
- struct io_pgtable_domain_attr pgtbl_cfg;
struct iommu_domain *iommu;
struct msm_mmu *mmu;
struct msm_gem_address_space *aspace;
@@ -202,13 +200,18 @@ adreno_iommu_create_address_space(struct msm_gpu *gpu,
if (!iommu)
return NULL;

- /*
- * This allows GPU to set the bus attributes required to use system
- * cache on behalf of the iommu page table walker.
- */
- if (!IS_ERR(a6xx_gpu->htw_llc_slice)) {
- pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_ARM_OUTER_WBWA;
- iommu_domain_set_attr(iommu, DOMAIN_ATTR_IO_PGTABLE_CFG, &pgtbl_cfg);
+
+ if (adreno_is_a6xx(adreno_gpu)) {
+ struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);
+ struct io_pgtable_domain_attr pgtbl_cfg;
+ /*
+ * This allows GPU to set the bus attributes required to use system
+ * cache on behalf of the iommu page table walker.
+ */
+ if (!IS_ERR(a6xx_gpu->htw_llc_slice)) {
+ pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_ARM_OUTER_WBWA;
+ iommu_domain_set_attr(iommu, DOMAIN_ATTR_IO_PGTABLE_CFG, &pgtbl_cfg);
+ }
}

mmu = msm_iommu_new(&pdev->dev, iommu);
diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
index 4574d85c5680..08421fa54a50 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.h
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.h
@@ -226,6 +226,11 @@ static inline int adreno_is_a540(struct adreno_gpu *gpu)
return gpu->revn == 540;
}

+static inline bool adreno_is_a6xx(struct adreno_gpu *gpu)
+{
+ return ((gpu->revn < 700 && gpu->revn > 599));
+}
+
static inline int adreno_is_a618(struct adreno_gpu *gpu)
{
return gpu->revn == 618;

--
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