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

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 make sure ASID and VMID space is unique across cavium SMMUv2.

changes from V3:
- Removed redundent variable.
- Used atomic_t for maintaining running total

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 <[email protected]>

Signed-off-by Akula Geethasowjanya <[email protected]>

---

Documentation/arm64/silicon-errata.txt             |  1 +
.../devicetree/bindings/iommu/arm,smmu.txt         |  1 +
drivers/iommu/arm-smmu.c                           | 42 ++++++++++++++++------
3 files changed, 33 insertions(+), 11 deletions(-)

Documentation/arm64/silicon-errata.txt +0 -0

index 58b71dd..3747a4b 100644
@@ -56,3 +56,4 @@ stable kernels.

|                |                 |                 |                         |
| Cavium         | ThunderX ITS    | #22375, #24313  | CAVIUM_ERRATUM_22375    |
| Cavium         | ThunderX GICv3  | #23154          | CAVIUM_ERRATUM_23154    |
+| Cavium         | ThunderX SMMUv2 | #27704          | N/A		       |

Documentation/devicetree/bindings/iommu/arm,smmu.txt +1 -0

index 7180745..19fe6f2 100644
@@ -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.

drivers/iommu/arm-smmu.c +31 -12

index 247a469..e793b0a 100644
@@ -326,6 +326,11 @@ struct arm_smmu_device {
 
 	struct list_head		list;
 	struct rb_root			masters;
+	/*
+	 *The following fields are specific to Cavium, Thunder
+	 */
+	u32				cavium_id_base;
+
 };
 
 struct arm_smmu_cfg {

@@ -335,8 +340,8 @@ 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 +369,8 @@ struct arm_smmu_option_prop {
 	const char *prop;
 };
 
+static atomic_t cavium_smmu_context_count = ATOMIC_INIT(0);
+
 static struct arm_smmu_option_prop arm_smmu_options[] = {
 	{ ARM_SMMU_OPT_SECURE_CFG_ACCESS, "calxeda,smmu-secure-config-access" },
 	{ 0, NULL},

@@ -575,11 +582,11 @@ 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 +608,7 @@ 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 +616,7 @@ 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 +636,7 @@ 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 +745,7 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain,
 #endif
 		/* 16-bit VMIDs live 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 +764,7 @@ 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)) {
 		/* 8-bit VMIDs live in CBAR */
-		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 +772,11 @@ 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 +1724,7 @@ 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);

@@ -1826,6 +1834,18 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev)
 			goto out_free_irqs;
 		}
 	}
+	/*
+	 * 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 (of_device_is_compatible(dev->of_node, "cavium,smmu-v2")) {
+		smmu->cavium_id_base = atomic_add_return(smmu->num_context_banks,
+				&cavium_smmu_context_count);
+		smmu->cavium_id_base -= smmu->num_context_banks;
+	}
 
 	INIT_LIST_HEAD(&smmu->list);
 	spin_lock(&arm_smmu_devices_lock);
--

2.1.0

Do you want me to resend it with path version number change?

Quoted 1 line · Tirumalesh

Do you want me to resend it with path version number change?

Shouldn't be any need. I've queued this locally, and will push out when I update my repo after the merge window.

Will

Thanks.

Quoted 6 lines · Will Deacon

Quoted 1 line · Tirumalesh

Do you want me to resend it with path version number change?

Shouldn't be any need. I've queued this locally, and will push out when I update my repo after the merge window.

Quoted 1 line

Will

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel at lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Quoted 5 lines · Tirumalesh

Thanks.

Quoted 8 lines

Quoted 6 lines · Will Deacon

Quoted 1 line · Tirumalesh

Do you want me to resend it with path version number change?

Shouldn't be any need. I've queued this locally, and will push out when I update my repo after the merge window.

Minor change that affects the kernel compilation.
I think it makes sense to resubmit the patch.

drivers/iommu/arm-smmu.c +2 -2

index 6ed7c3e..4aca5c1 100644
@@ -1834,8 +1834,8 @@ static int arm_smmu_device_dt_probe(struct
 platform_device *pdev)
         * asid/vmid space.
         */
        if (of_device_is_compatible(dev->of_node, "cavium,smmu-v2")) {
-               smmu->cavium_id_base = atomic_read(cavium_smmu_context_count);
-               atomic_add(smmu->num_context_banks, cavium_smmu_context_count);
+               smmu->cavium_id_base = atomic_read(&cavium_smmu_context_count);
+               atomic_add(smmu->num_context_banks, &cavium_smmu_context_count);
        }
 

        list_add(&smmu->list, &arm_smmu_devices);

Quoted 5 lines

Quoted 1 line

Will

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel at lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel