[PATCH 1/1] iommu/arm-smmu: Add SID information to context fault log

[Vivek Gautam]

Extract the SID and add the information to context fault log.
This is specially useful in a distributed smmu architecture
where multiple masters are connected to smmu. SID information
helps to quickly identify the faulting master device.

Signed-off-by: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>
---
 drivers/iommu/arm-smmu-regs.h |  4 ++++
 drivers/iommu/arm-smmu.c      | 14 ++++++++++++--
 2 files changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/iommu/arm-smmu-regs.h b/drivers/iommu/arm-smmu-regs.h
index a1226e4ab5f8..e5be0344b610 100644
--- a/drivers/iommu/arm-smmu-regs.h
+++ b/drivers/iommu/arm-smmu-regs.h
@@ -147,6 +147,10 @@ enum arm_smmu_s2cr_privcfg {
 #define CBAR_IRPTNDX_SHIFT		24
 #define CBAR_IRPTNDX_MASK		0xff
 
+#define ARM_SMMU_GR1_CBFRSYNRA(n)	(0x400 + ((n) << 2))
+#define CBFRSYNRA_V2_SID_MASK		0xffff
+#define CBFRSYNRA_V1_SID_MASK		0x7fff
+
 #define ARM_SMMU_GR1_CBA2R(n)		(0x800 + ((n) << 2))
 #define CBA2R_RW64_32BIT		(0 << 0)
 #define CBA2R_RW64_64BIT		(1 << 0)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 045d93884164..aa3426dc68d0 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -575,7 +575,10 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
 	struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
 	struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
+	void __iomem *gr1_base = ARM_SMMU_GR1(smmu);
 	void __iomem *cb_base;
+	u32 cbfrsynra;
+	u16 sid;
 
 	cb_base = ARM_SMMU_CB(smmu, cfg->cbndx);
 	fsr = readl_relaxed(cb_base + ARM_SMMU_CB_FSR);
@@ -586,9 +589,16 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
 	fsynr = readl_relaxed(cb_base + ARM_SMMU_CB_FSYNR0);
 	iova = readq_relaxed(cb_base + ARM_SMMU_CB_FAR);
 
+	cbfrsynra = readl_relaxed(gr1_base +
+				  ARM_SMMU_GR1_CBFRSYNRA(cfg->cbndx));
+	if (smmu->version > ARM_SMMU_V1)
+		sid = cbfrsynra & CBFRSYNRA_V2_SID_MASK;
+	else
+		sid = cbfrsynra & CBFRSYNRA_V1_SID_MASK;
+
 	dev_err_ratelimited(smmu->dev,
-	"Unhandled context fault: fsr=0x%x, iova=0x%08lx, fsynr=0x%x, cb=%d\n",
-			    fsr, iova, fsynr, cfg->cbndx);
+	"Unhandled context fault: fsr=0x%x, iova=0x%08lx, fsynr=0x%x, cb=%d sid = %u\n",
+			    fsr, iova, fsynr, cfg->cbndx, sid);
 
 	writel(fsr, cb_base + ARM_SMMU_CB_FSR);
 	return IRQ_HANDLED;
-- 
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