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authorBjorn Andersson <bjorn.andersson@linaro.org>2020-10-19 11:23:21 -0700
committerWill Deacon <will@kernel.org>2020-10-29 18:12:10 +0000
commit56b75b51ed6d5e7bffda59440404409bca2dff00 (patch)
tree854c99426a880fe760fff24e109274978ccb9a69 /drivers/iommu/arm/arm-smmu/arm-smmu.c
parent3650b228f83adda7e5ee532e2b90429c03f7b9ec (diff)
downloadlinux-56b75b51ed6d5e7bffda59440404409bca2dff00.tar.bz2
iommu/arm-smmu: Allow implementation specific write_s2cr
The firmware found in some Qualcomm platforms intercepts writes to the S2CR register in order to replace the BYPASS type with FAULT. Further more it treats faults at this level as catastrophic and restarts the device. Add support for providing implementation specific versions of the S2CR write function, to allow the Qualcomm driver to work around this behavior. Cc: <stable@vger.kernel.org> Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org> Tested-by: Steev Klimaszewski <steev@kali.org> Reviewed-by: Robin Murphy <robin.murphy@arm.com> Link: https://lore.kernel.org/r/20201019182323.3162386-2-bjorn.andersson@linaro.org Signed-off-by: Will Deacon <will@kernel.org>
Diffstat (limited to 'drivers/iommu/arm/arm-smmu/arm-smmu.c')
-rw-r--r--drivers/iommu/arm/arm-smmu/arm-smmu.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index dad7fa86fbd4..bcbacf22331d 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -929,9 +929,16 @@ static void arm_smmu_write_smr(struct arm_smmu_device *smmu, int idx)
static void arm_smmu_write_s2cr(struct arm_smmu_device *smmu, int idx)
{
struct arm_smmu_s2cr *s2cr = smmu->s2crs + idx;
- u32 reg = FIELD_PREP(ARM_SMMU_S2CR_TYPE, s2cr->type) |
- FIELD_PREP(ARM_SMMU_S2CR_CBNDX, s2cr->cbndx) |
- FIELD_PREP(ARM_SMMU_S2CR_PRIVCFG, s2cr->privcfg);
+ u32 reg;
+
+ if (smmu->impl && smmu->impl->write_s2cr) {
+ smmu->impl->write_s2cr(smmu, idx);
+ return;
+ }
+
+ reg = FIELD_PREP(ARM_SMMU_S2CR_TYPE, s2cr->type) |
+ FIELD_PREP(ARM_SMMU_S2CR_CBNDX, s2cr->cbndx) |
+ FIELD_PREP(ARM_SMMU_S2CR_PRIVCFG, s2cr->privcfg);
if (smmu->features & ARM_SMMU_FEAT_EXIDS && smmu->smrs &&
smmu->smrs[idx].valid)