[PATCH V2] iommu/arm-smmu-v2: Workaround for ThunderX errata#27704

tchalamarla at caviumnetworks.com tchalamarla at caviumnetworks.com
Thu Feb 18 10:29:18 PST 2016


From: Tirumalesh Chalamarla <tchalamarla at caviumnetworks.com>

Due to Errata#27704 CN88xx SMMUv2,supports  only shared ASID and VMID
namespaces; specifically within a given node SMMU0 and SMMU1 share,
as does SMMU2 and SMMU3.

This patch tries to address these issuee by supplying asid and vmid
base from devicetree.

changes from V1:
	- rebased on top of 16 bit VMID patch
	- removed redundent options from DT
	- insted of transform, DT now supplies starting ASID/VMID

Signed-off-by: Akula Geethasowjanya <Geethasowjanya.Akula at caviumnetworks.com>
Signed-off-by: Tirumalesh Chalamarla <tchalamarla at caviumnetworks.com>
---
 .../devicetree/bindings/iommu/arm,smmu.txt         |  8 +++++
 drivers/iommu/arm-smmu.c                           | 37 +++++++++++++++-------
 2 files changed, 34 insertions(+), 11 deletions(-)

diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
index bb7e569..80b8484 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
@@ -57,6 +57,14 @@ conditions.
 
 - smmu-enable-vmid16 : Enable 16 bit VMID, if allowed.
 
+- asid-base :	Buggy SMMUv2 implementations which doesn't satisfy the
+		ASID namespace needs, use this field to specify starting
+		ASID for the SMMU.
+
+- vmid-base :	Buggy SMMUv2 implementations which doesn't satisfy the VMID
+		namespace needs, use this field to specify starting VMID
+		for the SMMU.
+
 Example:
 
         smmu {
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 003c442..dc46b9a 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -320,6 +320,9 @@ struct arm_smmu_device {
 	unsigned long			ipa_size;
 	unsigned long			pa_size;
 
+	u32				asid_base;
+	u32				vmid_base;
+
 	u32				num_global_irqs;
 	u32				num_context_irqs;
 	unsigned int			*irqs;
@@ -335,8 +338,8 @@ struct arm_smmu_cfg {
 };
 #define INVALID_IRPTNDX			0xff
 
-#define ARM_SMMU_CB_ASID(cfg)		((cfg)->cbndx)
-#define ARM_SMMU_CB_VMID(cfg)		((cfg)->cbndx + 1)
+#define ARM_SMMU_CB_ASID(smmu, cfg)	((u16)((smmu)->asid_base + (cfg)->cbndx))
+#define ARM_SMMU_CB_VMID(smmu, cfg)	((u16)((smmu)->vmid_base + (cfg)->cbndx))
 
 enum arm_smmu_domain_stage {
 	ARM_SMMU_DOMAIN_S1 = 0,
@@ -576,11 +579,11 @@ static void arm_smmu_tlb_inv_context(void *cookie)
 
 	if (stage1) {
 		base = ARM_SMMU_CB_BASE(smmu) + ARM_SMMU_CB(smmu, cfg->cbndx);
-		writel_relaxed(ARM_SMMU_CB_ASID(cfg),
+		writel_relaxed(ARM_SMMU_CB_ASID(smmu, cfg),
 			       base + ARM_SMMU_CB_S1_TLBIASID);
 	} else {
 		base = ARM_SMMU_GR0(smmu);
-		writel_relaxed(ARM_SMMU_CB_VMID(cfg),
+		writel_relaxed(ARM_SMMU_CB_VMID(smmu, cfg),
 			       base + ARM_SMMU_GR0_TLBIVMID);
 	}
 
@@ -602,7 +605,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size,
 
 		if (!IS_ENABLED(CONFIG_64BIT) || smmu->version == ARM_SMMU_V1) {
 			iova &= ~12UL;
-			iova |= ARM_SMMU_CB_ASID(cfg);
+			iova |= ARM_SMMU_CB_ASID(smmu, cfg);
 			do {
 				writel_relaxed(iova, reg);
 				iova += granule;
@@ -610,7 +613,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size,
 #ifdef CONFIG_64BIT
 		} else {
 			iova >>= 12;
-			iova |= (u64)ARM_SMMU_CB_ASID(cfg) << 48;
+			iova |= (u64)ARM_SMMU_CB_ASID(smmu, cfg) << 48;
 			do {
 				writeq_relaxed(iova, reg);
 				iova += granule >> 12;
@@ -630,7 +633,7 @@ static void arm_smmu_tlb_inv_range_nosync(unsigned long iova, size_t size,
 #endif
 	} else {
 		reg = ARM_SMMU_GR0(smmu) + ARM_SMMU_GR0_TLBIVMID;
-		writel_relaxed(ARM_SMMU_CB_VMID(cfg), reg);
+		writel_relaxed(ARM_SMMU_CB_VMID(smmu, cfg), reg);
 	}
 }
 
@@ -744,7 +747,7 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain,
 #endif
 		/* if 16bit VMID required set VMID in CBA2R */
 		if (smmu->options & ARM_SMMU_OPT_ENABLE_VMID16)
-			reg |= ARM_SMMU_CB_VMID(cfg) << CBA2R_VMID_SHIFT;
+			reg |= ARM_SMMU_CB_VMID(smmu, cfg) << CBA2R_VMID_SHIFT;
 
 		writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBA2R(cfg->cbndx));
 	}
@@ -763,7 +766,7 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain,
 			(CBAR_S1_MEMATTR_WB << CBAR_S1_MEMATTR_SHIFT);
 	} else if (!(smmu->options & ARM_SMMU_OPT_ENABLE_VMID16)) {
 		/*16 bit VMID is not enabled set 8 bit VMID here */
-		reg |= ARM_SMMU_CB_VMID(cfg) << CBAR_VMID_SHIFT;
+		reg |= ARM_SMMU_CB_VMID(smmu, cfg) << CBAR_VMID_SHIFT;
 	}
 	writel_relaxed(reg, gr1_base + ARM_SMMU_GR1_CBAR(cfg->cbndx));
 
@@ -771,11 +774,11 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain,
 	if (stage1) {
 		reg64 = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[0];
 
-		reg64 |= ((u64)ARM_SMMU_CB_ASID(cfg)) << TTBRn_ASID_SHIFT;
+		reg64 |= ((u64)ARM_SMMU_CB_ASID(smmu, cfg)) << TTBRn_ASID_SHIFT;
 		smmu_writeq(reg64, cb_base + ARM_SMMU_CB_TTBR0);
 
 		reg64 = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[1];
-		reg64 |= ((u64)ARM_SMMU_CB_ASID(cfg)) << TTBRn_ASID_SHIFT;
+		reg64 |= ((u64)ARM_SMMU_CB_ASID(smmu, cfg)) << TTBRn_ASID_SHIFT;
 		smmu_writeq(reg64, cb_base + ARM_SMMU_CB_TTBR1);
 	} else {
 		reg64 = pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
@@ -1812,6 +1815,18 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 
 	parse_driver_options(smmu);
 
+	if (of_property_read_u32(dev->of_node, "#asid-base",
+				 &smmu->asid_base)) {
+		smmu->asid_base = 0;
+	}
+
+	if (of_property_read_u32(dev->of_node, "#vmid-base",
+				 &smmu->vmid_base)) {
+		smmu->vmid_base = 1;
+	}
+	if (smmu->vmid_base == 0)
+		smmu->vmid_base = 1;
+
 	if (smmu->version > ARM_SMMU_V1 &&
 	    smmu->num_context_banks != smmu->num_context_irqs) {
 		dev_err(dev,
-- 
2.1.0




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