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

Tirumalesh Chalamarla tchalamarla at caviumnetworks.com
Wed Feb 24 13:13:53 PST 2016


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 address these issuee by supplying asid and vmid
while calculating ASID and VMID for Thunder SMMUv2.

NOTE: resending with commit message fix.

changes from V2:
	- removed *_base from DT, and replaced with compatible string

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: Tirumalesh Chalamarla <tchalamarla at caviumnetworks.com>
Signed-off-by: Akula Geethasowjanya <Geethasowjanya.Akula at caviumnetworks.com>
---
 .../devicetree/bindings/iommu/arm,smmu.txt         |  1 +
 drivers/iommu/arm-smmu.c                           | 48 +++++++++++++++++-----
 2 files changed, 38 insertions(+), 11 deletions(-)

diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu.txt b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
index 7180745..19fe6f2 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu.txt
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu.txt
@@ -16,6 +16,7 @@ conditions.
                         "arm,mmu-400"
                         "arm,mmu-401"
                         "arm,mmu-500"
+                        "cavium,smmu-v2"
 
                   depending on the particular implementation and/or the
                   version of the architecture implemented.
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 247a469..c704f88 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -326,6 +326,12 @@ struct arm_smmu_device {
 
 	struct list_head		list;
 	struct rb_root			masters;
+	/*
+	 *The following fields are specific to Cavium, Thunder
+	 */
+	u32				cavium_smmu_id;
+	u32				cavium_id_base;
+
 };
 
 struct arm_smmu_cfg {
@@ -335,8 +341,8 @@ 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)->cavium_id_base + (cfg)->cbndx)
+#define ARM_SMMU_CB_VMID(smmu, cfg) ((u16)(smmu)->cavium_id_base + (cfg)->cbndx + 1)
 
 enum arm_smmu_domain_stage {
 	ARM_SMMU_DOMAIN_S1 = 0,
@@ -364,6 +370,8 @@ struct arm_smmu_option_prop {
 	const char *prop;
 };
 
+static int cavium_smmu_count;
+
 static struct arm_smmu_option_prop arm_smmu_options[] = {
 	{ ARM_SMMU_OPT_SECURE_CFG_ACCESS, "calxeda,smmu-secure-config-access" },
 	{ 0, NULL},
@@ -575,11 +583,11 @@ 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);
 	}
 
@@ -601,7 +609,7 @@ 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;
@@ -609,7 +617,7 @@ 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;
@@ -629,7 +637,7 @@ 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);
 	}
 }
 
@@ -738,7 +746,7 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain,
 #endif
 		/* if 16bit VMID supported set VMID in CBA2R */
 		if (smmu->features & ARM_SMMU_FEAT_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));
 	}
@@ -757,7 +765,7 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain,
 			(CBAR_S1_MEMATTR_WB << CBAR_S1_MEMATTR_SHIFT);
 	} else if (!(smmu->features & ARM_SMMU_FEAT_VMID16)) {
 		/*16 bit VMID is not supported 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));
 
@@ -765,11 +773,11 @@ 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;
@@ -1717,6 +1725,7 @@ static const struct of_device_id arm_smmu_of_match[] = {
 	{ .compatible = "arm,mmu-400", .data = (void *)ARM_SMMU_V1 },
 	{ .compatible = "arm,mmu-401", .data = (void *)ARM_SMMU_V1 },
 	{ .compatible = "arm,mmu-500", .data = (void *)ARM_SMMU_V2 },
+	{ .compatible = "cavium,smmu-v2", .data = (void *)ARM_SMMU_V2 },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
@@ -1827,6 +1836,23 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 		}
 	}
 
+	/*
+	 * 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. see if this is a Cavium SMMU, if so
+	 * set asid and vmid base such that each SMMU gets unique
+	 * asid/vmid space.
+	 */
+	if (!strcasecmp(of_id->compatible, "cavium,smmu-v2")) {
+		/* VMID16 must be present on Cavium SMMUv2*/
+		if (!(smmu->features & ARM_SMMU_FEAT_VMID16))
+			goto out_free_irqs;
+		smmu->cavium_smmu_id = cavium_smmu_count;
+		cavium_smmu_count++;
+		smmu->cavium_id_base =
+			(smmu->cavium_smmu_id * ARM_SMMU_MAX_CBS);
+	}
+
 	INIT_LIST_HEAD(&smmu->list);
 	spin_lock(&arm_smmu_devices_lock);
 	list_add(&smmu->list, &arm_smmu_devices);
-- 
2.1.0




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