From 792c2bf3a5dd4e4babd40ed3ad2d85f126f10632 Mon Sep 17 00:00:00 2001 From: Jordan Crouse Date: Tue, 9 Jun 2020 12:05:16 -0600 Subject: [PATCH] FROMGIT: iommu/arm-smmu: Don't bypass pinned stream mappings Commit 0e764a01015d ("iommu/arm-smmu: Allow client devices to select direct mapping") sets the initial domain type to SMMU_DOMAIN_IDENTITY for devices that select direct mapping. This ends up setting the domain as ARM_SMMU_DOMAIN_BYPASS which causes the stream ID mappings for the device to be programmed to S2CR_TYPE_BYPASS. This causes a problem for stream mappings that are inherited from the bootloader since rewriting the stream to BYPASS will disrupt the display controller access to DDR. This is an extension to ("iommu/arm-smmu: Allow inheriting stream mapping from bootloader") [1] that identifies streams that are already configured and marked them as pinned. This patch extends that to not re-write pinned stream mappings for ARM_SMMU_DOMAIN_BYPASS domains. [1] https://lore.kernel.org/r/20191226221709.3844244-4-bjorn.andersson@linaro.org Signed-off-by: Jordan Crouse Signed-off-by: John Stultz (cherry picked from commit 7ea70cbadd53c199b36f6d2433183dfcb9b1fbdb https://github.com/freedreno/kernel-msm.git wip/c630-5.8-rc1) Change-Id: Iecc6e3d1feedee178e04f7da8f601ee12bd5ae3b --- drivers/iommu/arm-smmu.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index b4c8655c70f4..f90e53bd918b 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -1143,6 +1143,10 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain, if (type == s2cr[idx].type && cbndx == s2cr[idx].cbndx) continue; + /* Don't bypasss pinned streams; leave them as they are */ + if (type == S2CR_TYPE_BYPASS && s2cr[idx].pinned) + continue; + s2cr[idx].type = type; s2cr[idx].privcfg = S2CR_PRIVCFG_DEFAULT; s2cr[idx].cbndx = cbndx;