From: Bjorn Andersson <bjorn.andersson@linaro.org>
To: Joerg Roedel <joro@8bytes.org>, Will Deacon <will.deacon@arm.com>,
Robin Murphy <robin.murphy@arm.com>
Cc: Vivek Gautam <vivek.gautam@codeaurora.org>,
Jeffrey Hugo <jhugo@codeaurora.org>,
Patrick Daly <pdaly@codeaurora.org>,
iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-arm-msm@vger.kernel.org
Subject: [RFC 2/2] iommu: arm-smmu: Don't blindly use first SMR to calculate mask
Date: Wed, 5 Jun 2019 14:08:56 -0700 [thread overview]
Message-ID: <20190605210856.20677-3-bjorn.andersson@linaro.org> (raw)
In-Reply-To: <20190605210856.20677-1-bjorn.andersson@linaro.org>
With the SMRs inherited from the bootloader the first SMR might actually
be valid and in use. As such probing the SMR mask using the first SMR
might break a stream in use. Search for an unused stream and use this to
probe the SMR mask.
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
---
drivers/iommu/arm-smmu.c | 20 ++++++++++++++++----
1 file changed, 16 insertions(+), 4 deletions(-)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index c8629a656b42..0c6f5fe6f382 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1084,23 +1084,35 @@ static void arm_smmu_test_smr_masks(struct arm_smmu_device *smmu)
{
void __iomem *gr0_base = ARM_SMMU_GR0(smmu);
u32 smr;
+ int idx;
if (!smmu->smrs)
return;
+ for (idx = 0; idx < smmu->num_mapping_groups; idx++) {
+ smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(idx));
+ if (!(smr & SMR_VALID))
+ break;
+ }
+
+ if (idx == smmu->num_mapping_groups) {
+ dev_err(smmu->dev, "Unable to compute streamid_mask\n");
+ return;
+ }
+
/*
* SMR.ID bits may not be preserved if the corresponding MASK
* bits are set, so check each one separately. We can reject
* masters later if they try to claim IDs outside these masks.
*/
smr = smmu->streamid_mask << SMR_ID_SHIFT;
- writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(0));
- smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(0));
+ writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(idx));
+ smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(idx));
smmu->streamid_mask = smr >> SMR_ID_SHIFT;
smr = smmu->streamid_mask << SMR_MASK_SHIFT;
- writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(0));
- smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(0));
+ writel_relaxed(smr, gr0_base + ARM_SMMU_GR0_SMR(idx));
+ smr = readl_relaxed(gr0_base + ARM_SMMU_GR0_SMR(idx));
smmu->smr_mask_mask = smr >> SMR_MASK_SHIFT;
}
--
2.18.0
next prev parent reply other threads:[~2019-06-05 21:09 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-05 21:08 [RFC 0/2] iommu: arm-smmu: Inherit SMR and CB config during init Bjorn Andersson
2019-06-05 21:08 ` [RFC 1/2] iommu: arm-smmu: Handoff SMR registers and context banks Bjorn Andersson
2019-06-12 18:07 ` Jeffrey Hugo
2019-06-12 18:42 ` Bjorn Andersson
2019-06-12 19:16 ` Jeffrey Hugo
2019-06-13 11:23 ` Robin Murphy
2019-06-13 22:49 ` Bjorn Andersson
2019-06-05 21:08 ` Bjorn Andersson [this message]
2019-06-12 17:58 ` [RFC 2/2] iommu: arm-smmu: Don't blindly use first SMR to calculate mask Jeffrey Hugo
2019-06-12 18:28 ` Bjorn Andersson
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