[v4 0/4] Cavium ThunderX2 SMMUv3 errata workarounds

[v4 0/4] Cavium ThunderX2 SMMUv3 errata workarounds

[Geetha sowjanya]

From: Linu Cherian <linu.cherian@cavium.com>

Cavium ThunderX2 SMMUv3 implementation has two Silicon Erratas.
1. Errata ID #74
   SMMU register alias Page 1 is not implemented
2. Errata ID #126
   SMMU doesnt support unique IRQ lines and also MSI for gerror,
   eventq and cmdq-sync

The following patchset does software workaround for these two erratas.

This series is based on patchset.
https://www.spinics.net/lists/arm-kernel/msg578443.html

Changes from v3:
 - Merged patches 1, 2 and 4 of Version 3.
 - Modified the page1_offset_adjust() and get_irq_flags() implementation as 
   suggested by Robin. 

Changes from v2:
 Updated "Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt" document with
 new SMMU option used to enable errata workaround.

Changes from v1:
 Since the use of MIDR register is rejected and SMMU_IIDR is broken on this
 silicon, as suggested by Will Deacon modified the patches to use ThunderX2
 SMMUv3 IORT model number to enable errata workaround.


Geetha Sowjanya (1):
  iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126

Linu Cherian (3):
  ACPICA: IORT: Add Cavium ThunderX2 SMMUv3 model definition.
  ACPI/IORT: Fixup SMMUv3 resource size for Cavium ThunderX2 SMMUv3
    model
  iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74

 Documentation/arm64/silicon-errata.txt             |   2 +
 .../devicetree/bindings/iommu/arm,smmu-v3.txt      |   6 ++
 drivers/acpi/arm64/iort.c                          |  10 +-
 drivers/iommu/arm-smmu-v3.c                        | 109 ++++++++++++++++-----
 include/acpi/actbl2.h                              |   2 +
 5 files changed, 103 insertions(+), 26 deletions(-)

-- 
1.8.3.1

[v4 1/4] ACPICA: IORT: Add Cavium ThunderX2 SMMUv3 model definition.

[Geetha sowjanya]

From: Linu Cherian <linu.cherian@cavium.com>

Add SMMUv3 model definition for ThunderX2.

Signed-off-by: Linu Cherian <linu.cherian@cavium.com>
Signed-off-by: Geetha Sowjanya <geethasowjanya.akula@cavium.com>
---
 include/acpi/actbl2.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/acpi/actbl2.h b/include/acpi/actbl2.h
index faa9f2c..76a6f5d 100644
--- a/include/acpi/actbl2.h
+++ b/include/acpi/actbl2.h
@@ -779,6 +779,8 @@ struct acpi_iort_smmu {
 #define ACPI_IORT_SMMU_CORELINK_MMU400  0x00000002	/* ARM Corelink MMU-400 */
 #define ACPI_IORT_SMMU_CORELINK_MMU500  0x00000003	/* ARM Corelink MMU-500 */
 
+#define ACPI_IORT_SMMU_V3_CAVIUM_CN99XX 0x00000002 /* Cavium ThunderX2 SMMUv3 */
+
 /* Masks for Flags field above */
 
 #define ACPI_IORT_SMMU_DVM_SUPPORTED    (1)
-- 
1.8.3.1

[v4 2/4] ACPI/IORT: Fixup SMMUv3 resource size for Cavium ThunderX2 SMMUv3 model

[Geetha sowjanya]

From: Linu Cherian <linu.cherian@cavium.com>

Cavium ThunderX2 implementation doesn't support second page in SMMU
register space. Hence, resource size is set as 64k for this model.

Signed-off-by: Linu Cherian <linu.cherian@cavium.com>
Signed-off-by: Geetha Sowjanya <geethasowjanya.akula@cavium.com>
---
 drivers/acpi/arm64/iort.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index c5fecf9..23c5350 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -833,12 +833,20 @@ static void __init arm_smmu_v3_init_resources(struct resource *res,
 {
 	struct acpi_iort_smmu_v3 *smmu;
 	int num_res = 0;
+	unsigned long size = SZ_128K;
 
 	/* Retrieve SMMUv3 specific data */
 	smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
 
+	/*
+	 * Override the size, for Cavium ThunderX2 implementation
+	 * which doesn't support the page 1 SMMU register space.
+	 */
+	if (smmu->model == ACPI_IORT_SMMU_V3_CAVIUM_CN99XX)
+		size = SZ_64K;
+
 	res[num_res].start = smmu->base_address;
-	res[num_res].end = smmu->base_address + SZ_128K - 1;
+	res[num_res].end = smmu->base_address + size - 1;
 	res[num_res].flags = IORESOURCE_MEM;
 
 	num_res++;
-- 
1.8.3.1

[v4 3/4] iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74

[Geetha sowjanya]

From: Linu Cherian <linu.cherian@cavium.com>

Cavium ThunderX2 SMMU implementation doesn't support page 1 register space
and PAGE0_REGS_ONLY option is enabled as an errata workaround.
This option when turned on, replaces all page 1 offsets used for
EVTQ_PROD/CONS, PRIQ_PROD/CONS register access with page 0 offsets.

SMMU resource size checks are now based on SMMU option PAGE0_REGS_ONLY,
since resource size can be either 64k/128k.
For this, arm_smmu_device_dt_probe/acpi_probe has been moved before
platform_get_resource call, so that SMMU options are set beforehand.

Signed-off-by: Linu Cherian <linu.cherian@cavium.com>
Signed-off-by: Geetha Sowjanya <geethasowjanya.akula@cavium.com>
---
 Documentation/arm64/silicon-errata.txt             |  1 +
 .../devicetree/bindings/iommu/arm,smmu-v3.txt      |  6 ++
 drivers/iommu/arm-smmu-v3.c                        | 80 ++++++++++++++++------
 3 files changed, 66 insertions(+), 21 deletions(-)

diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
index 10f2ddd..4693a32 100644
--- a/Documentation/arm64/silicon-errata.txt
+++ b/Documentation/arm64/silicon-errata.txt
@@ -62,6 +62,7 @@ stable kernels.
 | Cavium         | ThunderX GICv3  | #23154          | CAVIUM_ERRATUM_23154        |
 | Cavium         | ThunderX Core   | #27456          | CAVIUM_ERRATUM_27456        |
 | Cavium         | ThunderX SMMUv2 | #27704          | N/A                         |
+| Cavium         | ThunderX2 SMMUv3| #74             | N/A                         |
 |                |                 |                 |                             |
 | Freescale/NXP  | LS2080A/LS1043A | A-008585        | FSL_ERRATUM_A008585         |
 |                |                 |                 |                             |
diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
index be57550..e6da62b 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
@@ -49,6 +49,12 @@ the PCIe specification.
 - hisilicon,broken-prefetch-cmd
                     : Avoid sending CMD_PREFETCH_* commands to the SMMU.
 
+- cavium-cn99xx,broken-page1-regspace
+                    : Replaces all page 1 offsets used for EVTQ_PROD/CONS,
+						PRIQ_PROD/CONS register access with page 0 offsets.
+						Set for Caviun ThunderX2 silicon that doesn't support
+						SMMU page1 register space.
+
 ** Example
 
         smmu@2b400000 {
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 380969a..1e986a0 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -176,15 +176,15 @@
 #define ARM_SMMU_CMDQ_CONS		0x9c
 
 #define ARM_SMMU_EVTQ_BASE		0xa0
-#define ARM_SMMU_EVTQ_PROD		0x100a8
-#define ARM_SMMU_EVTQ_CONS		0x100ac
+#define ARM_SMMU_EVTQ_PROD(smmu)	(page1_offset_adjust(0x100a8, smmu))
+#define ARM_SMMU_EVTQ_CONS(smmu)	(page1_offset_adjust(0x100ac, smmu))
 #define ARM_SMMU_EVTQ_IRQ_CFG0		0xb0
 #define ARM_SMMU_EVTQ_IRQ_CFG1		0xb8
 #define ARM_SMMU_EVTQ_IRQ_CFG2		0xbc
 
 #define ARM_SMMU_PRIQ_BASE		0xc0
-#define ARM_SMMU_PRIQ_PROD		0x100c8
-#define ARM_SMMU_PRIQ_CONS		0x100cc
+#define ARM_SMMU_PRIQ_PROD(smmu)	(page1_offset_adjust(0x100c8, smmu))
+#define ARM_SMMU_PRIQ_CONS(smmu)	(page1_offset_adjust(0x100cc, smmu))
 #define ARM_SMMU_PRIQ_IRQ_CFG0		0xd0
 #define ARM_SMMU_PRIQ_IRQ_CFG1		0xd8
 #define ARM_SMMU_PRIQ_IRQ_CFG2		0xdc
@@ -412,6 +412,9 @@
 #define MSI_IOVA_BASE			0x8000000
 #define MSI_IOVA_LENGTH			0x100000
 
+#define ARM_SMMU_PAGE0_REGS_ONLY(smmu)		\
+	((smmu)->options & ARM_SMMU_OPT_PAGE0_REGS_ONLY)
+
 static bool disable_bypass;
 module_param_named(disable_bypass, disable_bypass, bool, S_IRUGO);
 MODULE_PARM_DESC(disable_bypass,
@@ -597,6 +600,7 @@ struct arm_smmu_device {
 	u32				features;
 
 #define ARM_SMMU_OPT_SKIP_PREFETCH	(1 << 0)
+#define ARM_SMMU_OPT_PAGE0_REGS_ONLY    (1 << 1)
 	u32				options;
 
 	struct arm_smmu_cmdq		cmdq;
@@ -663,9 +667,19 @@ struct arm_smmu_option_prop {
 
 static struct arm_smmu_option_prop arm_smmu_options[] = {
 	{ ARM_SMMU_OPT_SKIP_PREFETCH, "hisilicon,broken-prefetch-cmd" },
+	{ ARM_SMMU_OPT_PAGE0_REGS_ONLY, "cavium-cn99xx,broken-page1-regspace"},
 	{ 0, NULL},
 };
 
+static inline unsigned long page1_offset_adjust(
+	unsigned long off, struct arm_smmu_device *smmu)
+{
+	if (off > SZ_64K && ARM_SMMU_PAGE0_REGS_ONLY(smmu))
+		return (off - SZ_64K);
+
+	return off;
+}
+
 static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
 {
 	return container_of(dom, struct arm_smmu_domain, domain);
@@ -1986,8 +2000,10 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
 		return ret;
 
 	/* evtq */
-	ret = arm_smmu_init_one_queue(smmu, &smmu->evtq.q, ARM_SMMU_EVTQ_PROD,
-				      ARM_SMMU_EVTQ_CONS, EVTQ_ENT_DWORDS);
+	ret = arm_smmu_init_one_queue(smmu, &smmu->evtq.q,
+				      ARM_SMMU_EVTQ_PROD(smmu),
+				      ARM_SMMU_EVTQ_CONS(smmu),
+				      EVTQ_ENT_DWORDS);
 	if (ret)
 		return ret;
 
@@ -1995,8 +2011,10 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
 	if (!(smmu->features & ARM_SMMU_FEAT_PRI))
 		return 0;
 
-	return arm_smmu_init_one_queue(smmu, &smmu->priq.q, ARM_SMMU_PRIQ_PROD,
-				       ARM_SMMU_PRIQ_CONS, PRIQ_ENT_DWORDS);
+	return arm_smmu_init_one_queue(smmu, &smmu->priq.q,
+				       ARM_SMMU_PRIQ_PROD(smmu),
+				       ARM_SMMU_PRIQ_CONS(smmu),
+				       PRIQ_ENT_DWORDS);
 }
 
 static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
@@ -2363,8 +2381,10 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
 
 	/* Event queue */
 	writeq_relaxed(smmu->evtq.q.q_base, smmu->base + ARM_SMMU_EVTQ_BASE);
-	writel_relaxed(smmu->evtq.q.prod, smmu->base + ARM_SMMU_EVTQ_PROD);
-	writel_relaxed(smmu->evtq.q.cons, smmu->base + ARM_SMMU_EVTQ_CONS);
+	writel_relaxed(smmu->evtq.q.prod, smmu->base +
+		       ARM_SMMU_EVTQ_PROD(smmu));
+	writel_relaxed(smmu->evtq.q.cons, smmu->base +
+		       ARM_SMMU_EVTQ_CONS(smmu));
 
 	enables |= CR0_EVTQEN;
 	ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
@@ -2379,9 +2399,9 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
 		writeq_relaxed(smmu->priq.q.q_base,
 			       smmu->base + ARM_SMMU_PRIQ_BASE);
 		writel_relaxed(smmu->priq.q.prod,
-			       smmu->base + ARM_SMMU_PRIQ_PROD);
+			       smmu->base + ARM_SMMU_PRIQ_PROD(smmu));
 		writel_relaxed(smmu->priq.q.cons,
-			       smmu->base + ARM_SMMU_PRIQ_CONS);
+			       smmu->base + ARM_SMMU_PRIQ_CONS(smmu));
 
 		enables |= CR0_PRIQEN;
 		ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
@@ -2605,6 +2625,14 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
 }
 
 #ifdef CONFIG_ACPI
+static void acpi_smmu_get_options(u32 model, struct arm_smmu_device *smmu)
+{
+	if (model == ACPI_IORT_SMMU_V3_CAVIUM_CN99XX)
+		smmu->options |= ARM_SMMU_OPT_PAGE0_REGS_ONLY;
+
+	dev_notice(smmu->dev, "option mask 0x%x\n", smmu->options);
+}
+
 static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
 				      struct arm_smmu_device *smmu)
 {
@@ -2617,6 +2645,8 @@ static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
 	/* Retrieve SMMUv3 specific data */
 	iort_smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
 
+	acpi_smmu_get_options(iort_smmu->model, smmu);
+
 	if (iort_smmu->flags & ACPI_IORT_SMMU_V3_COHACC_OVERRIDE)
 		smmu->features |= ARM_SMMU_FEAT_COHERENCY;
 
@@ -2652,6 +2682,14 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev,
 	return ret;
 }
 
+static unsigned long arm_smmu_resource_size(struct arm_smmu_device *smmu)
+{
+	if (ARM_SMMU_PAGE0_REGS_ONLY(smmu))
+		return SZ_64K;
+	else
+		return SZ_128K;
+}
+
 static int arm_smmu_device_probe(struct platform_device *pdev)
 {
 	int irq, ret;
@@ -2668,9 +2706,17 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	}
 	smmu->dev = dev;
 
+	if (dev->of_node) {
+		ret = arm_smmu_device_dt_probe(pdev, smmu);
+	} else {
+		ret = arm_smmu_device_acpi_probe(pdev, smmu);
+		if (ret == -ENODEV)
+			return ret;
+	}
+
 	/* Base address */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	if (resource_size(res) + 1 < SZ_128K) {
+	if (resource_size(res) + 1 < arm_smmu_resource_size(smmu)) {
 		dev_err(dev, "MMIO region too small (%pr)\n", res);
 		return -EINVAL;
 	}
@@ -2697,14 +2743,6 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	if (irq > 0)
 		smmu->gerr_irq = irq;
 
-	if (dev->of_node) {
-		ret = arm_smmu_device_dt_probe(pdev, smmu);
-	} else {
-		ret = arm_smmu_device_acpi_probe(pdev, smmu);
-		if (ret == -ENODEV)
-			return ret;
-	}
-
 	/* Set bypass mode according to firmware probing result */
 	bypass = !!ret;
 
-- 
1.8.3.1

[v4 4/4] iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126

[Geetha sowjanya]

From: Geetha Sowjanya <geethasowjanya.akula@cavium.com>

Cavium ThunderX2 SMMU doesn't support MSI and also doesn't have unique irq
lines for gerror, eventq and cmdq-sync.

This patch addresses the issue by checking if any interrupt sources are
using same irq number, then they are registered as shared irqs.

Signed-off-by: Geetha Sowjanya <geethasowjanya.akula@cavium.com>
---
 Documentation/arm64/silicon-errata.txt |  1 +
 drivers/iommu/arm-smmu-v3.c            | 29 +++++++++++++++++++++++++----
 2 files changed, 26 insertions(+), 4 deletions(-)

diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
index 4693a32..42422f6 100644
--- a/Documentation/arm64/silicon-errata.txt
+++ b/Documentation/arm64/silicon-errata.txt
@@ -63,6 +63,7 @@ stable kernels.
 | Cavium         | ThunderX Core   | #27456          | CAVIUM_ERRATUM_27456        |
 | Cavium         | ThunderX SMMUv2 | #27704          | N/A                         |
 | Cavium         | ThunderX2 SMMUv3| #74             | N/A                         |
+| Cavium         | ThunderX2 SMMUv3| #126            | N/A                         |
 |                |                 |                 |                             |
 | Freescale/NXP  | LS2080A/LS1043A | A-008585        | FSL_ERRATUM_A008585         |
 |                |                 |                 |                             |
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 1e986a0..a1c09f4 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -2236,6 +2236,25 @@ static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
 	devm_add_action(dev, arm_smmu_free_msis, dev);
 }
 
+static int get_irq_flags(struct arm_smmu_device *smmu, int irq)
+{
+	int match_count = 0;
+
+	if (irq == smmu->evtq.q.irq)
+		match_count++;
+	if (irq == smmu->cmdq.q.irq)
+		match_count++;
+	if (irq == smmu->gerr_irq)
+		match_count++;
+	if (irq == smmu->priq.q.irq)
+		match_count++;
+
+	if (match_count > 1)
+		return IRQF_SHARED | IRQF_ONESHOT;
+
+	return IRQF_ONESHOT;
+}
+
 static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
 {
 	int ret, irq;
@@ -2256,7 +2275,7 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
 	if (irq) {
 		ret = devm_request_threaded_irq(smmu->dev, irq, NULL,
 						arm_smmu_evtq_thread,
-						IRQF_ONESHOT,
+						get_irq_flags(smmu, irq),
 						"arm-smmu-v3-evtq", smmu);
 		if (ret < 0)
 			dev_warn(smmu->dev, "failed to enable evtq irq\n");
@@ -2265,7 +2284,8 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
 	irq = smmu->cmdq.q.irq;
 	if (irq) {
 		ret = devm_request_irq(smmu->dev, irq,
-				       arm_smmu_cmdq_sync_handler, 0,
+				       arm_smmu_cmdq_sync_handler,
+					   get_irq_flags(smmu, irq),
 				       "arm-smmu-v3-cmdq-sync", smmu);
 		if (ret < 0)
 			dev_warn(smmu->dev, "failed to enable cmdq-sync irq\n");
@@ -2274,7 +2294,8 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
 	irq = smmu->gerr_irq;
 	if (irq) {
 		ret = devm_request_irq(smmu->dev, irq, arm_smmu_gerror_handler,
-				       0, "arm-smmu-v3-gerror", smmu);
+						get_irq_flags(smmu, irq),
+						"arm-smmu-v3-gerror", smmu);
 		if (ret < 0)
 			dev_warn(smmu->dev, "failed to enable gerror irq\n");
 	}
@@ -2284,7 +2305,7 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
 		if (irq) {
 			ret = devm_request_threaded_irq(smmu->dev, irq, NULL,
 							arm_smmu_priq_thread,
-							IRQF_ONESHOT,
+							get_irq_flags(smmu, irq),
 							"arm-smmu-v3-priq",
 							smmu);
 			if (ret < 0)
-- 
1.8.3.1

Re: [v4 3/4] iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74

[Robin Murphy]

On 09/05/17 12:45, Geetha sowjanya wrote:
> From: Linu Cherian <linu.cherian@cavium.com>
> 
> Cavium ThunderX2 SMMU implementation doesn't support page 1 register space
> and PAGE0_REGS_ONLY option is enabled as an errata workaround.
> This option when turned on, replaces all page 1 offsets used for
> EVTQ_PROD/CONS, PRIQ_PROD/CONS register access with page 0 offsets.
> 
> SMMU resource size checks are now based on SMMU option PAGE0_REGS_ONLY,
> since resource size can be either 64k/128k.
> For this, arm_smmu_device_dt_probe/acpi_probe has been moved before
> platform_get_resource call, so that SMMU options are set beforehand.
> 
> Signed-off-by: Linu Cherian <linu.cherian@cavium.com>
> Signed-off-by: Geetha Sowjanya <geethasowjanya.akula@cavium.com>
> ---
>  Documentation/arm64/silicon-errata.txt             |  1 +
>  .../devicetree/bindings/iommu/arm,smmu-v3.txt      |  6 ++
>  drivers/iommu/arm-smmu-v3.c                        | 80 ++++++++++++++++------
>  3 files changed, 66 insertions(+), 21 deletions(-)
> 
> diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
> index 10f2ddd..4693a32 100644
> --- a/Documentation/arm64/silicon-errata.txt
> +++ b/Documentation/arm64/silicon-errata.txt
> @@ -62,6 +62,7 @@ stable kernels.
>  | Cavium         | ThunderX GICv3  | #23154          | CAVIUM_ERRATUM_23154        |
>  | Cavium         | ThunderX Core   | #27456          | CAVIUM_ERRATUM_27456        |
>  | Cavium         | ThunderX SMMUv2 | #27704          | N/A                         |
> +| Cavium         | ThunderX2 SMMUv3| #74             | N/A                         |
>  |                |                 |                 |                             |
>  | Freescale/NXP  | LS2080A/LS1043A | A-008585        | FSL_ERRATUM_A008585         |
>  |                |                 |                 |                             |
> diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> index be57550..e6da62b 100644
> --- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> +++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> @@ -49,6 +49,12 @@ the PCIe specification.
>  - hisilicon,broken-prefetch-cmd
>                      : Avoid sending CMD_PREFETCH_* commands to the SMMU.
>  
> +- cavium-cn99xx,broken-page1-regspace
> +                    : Replaces all page 1 offsets used for EVTQ_PROD/CONS,
> +						PRIQ_PROD/CONS register access with page 0 offsets.
> +						Set for Caviun ThunderX2 silicon that doesn't support
> +						SMMU page1 register space.
> +
>  ** Example
>  
>          smmu@2b400000 {
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index 380969a..1e986a0 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -176,15 +176,15 @@
>  #define ARM_SMMU_CMDQ_CONS		0x9c
>  
>  #define ARM_SMMU_EVTQ_BASE		0xa0
> -#define ARM_SMMU_EVTQ_PROD		0x100a8
> -#define ARM_SMMU_EVTQ_CONS		0x100ac
> +#define ARM_SMMU_EVTQ_PROD(smmu)	(page1_offset_adjust(0x100a8, smmu))
> +#define ARM_SMMU_EVTQ_CONS(smmu)	(page1_offset_adjust(0x100ac, smmu))

Sorry, perhaps I should have communicated the rest of the idea more
explicitly - you now don't need to change these definitions...

>  #define ARM_SMMU_EVTQ_IRQ_CFG0		0xb0
>  #define ARM_SMMU_EVTQ_IRQ_CFG1		0xb8
>  #define ARM_SMMU_EVTQ_IRQ_CFG2		0xbc
>  
>  #define ARM_SMMU_PRIQ_BASE		0xc0
> -#define ARM_SMMU_PRIQ_PROD		0x100c8
> -#define ARM_SMMU_PRIQ_CONS		0x100cc
> +#define ARM_SMMU_PRIQ_PROD(smmu)	(page1_offset_adjust(0x100c8, smmu))
> +#define ARM_SMMU_PRIQ_CONS(smmu)	(page1_offset_adjust(0x100cc, smmu))
>  #define ARM_SMMU_PRIQ_IRQ_CFG0		0xd0
>  #define ARM_SMMU_PRIQ_IRQ_CFG1		0xd8
>  #define ARM_SMMU_PRIQ_IRQ_CFG2		0xdc
> @@ -412,6 +412,9 @@
>  #define MSI_IOVA_BASE			0x8000000
>  #define MSI_IOVA_LENGTH			0x100000
>  
> +#define ARM_SMMU_PAGE0_REGS_ONLY(smmu)		\
> +	((smmu)->options & ARM_SMMU_OPT_PAGE0_REGS_ONLY)
> +
>  static bool disable_bypass;
>  module_param_named(disable_bypass, disable_bypass, bool, S_IRUGO);
>  MODULE_PARM_DESC(disable_bypass,
> @@ -597,6 +600,7 @@ struct arm_smmu_device {
>  	u32				features;
>  
>  #define ARM_SMMU_OPT_SKIP_PREFETCH	(1 << 0)
> +#define ARM_SMMU_OPT_PAGE0_REGS_ONLY    (1 << 1)
>  	u32				options;
>  
>  	struct arm_smmu_cmdq		cmdq;
> @@ -663,9 +667,19 @@ struct arm_smmu_option_prop {
>  
>  static struct arm_smmu_option_prop arm_smmu_options[] = {
>  	{ ARM_SMMU_OPT_SKIP_PREFETCH, "hisilicon,broken-prefetch-cmd" },
> +	{ ARM_SMMU_OPT_PAGE0_REGS_ONLY, "cavium-cn99xx,broken-page1-regspace"},
>  	{ 0, NULL},
>  };
>  
> +static inline unsigned long page1_offset_adjust(
> +	unsigned long off, struct arm_smmu_device *smmu)
> +{
> +	if (off > SZ_64K && ARM_SMMU_PAGE0_REGS_ONLY(smmu))
> +		return (off - SZ_64K);
> +
> +	return off;
> +}
> +
>  static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
>  {
>  	return container_of(dom, struct arm_smmu_domain, domain);
> @@ -1986,8 +2000,10 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
>  		return ret;
>  
>  	/* evtq */
> -	ret = arm_smmu_init_one_queue(smmu, &smmu->evtq.q, ARM_SMMU_EVTQ_PROD,
> -				      ARM_SMMU_EVTQ_CONS, EVTQ_ENT_DWORDS);
> +	ret = arm_smmu_init_one_queue(smmu, &smmu->evtq.q,
> +				      ARM_SMMU_EVTQ_PROD(smmu),
> +				      ARM_SMMU_EVTQ_CONS(smmu),
> +				      EVTQ_ENT_DWORDS);

...or these callsites; you can just use page1_offset_adjust() directly
within arm_smmu_init_one_queue(), i.e.


       q->prod_reg = smmu->base + page1_offset_adjust(prod_off, smmu);
       q->cons_reg = smmu->base + page1_offset_adjust(cons_off, smmu);

because it won't affect page 0 offsets either way.

>  	if (ret)
>  		return ret;
>  
> @@ -1995,8 +2011,10 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
>  	if (!(smmu->features & ARM_SMMU_FEAT_PRI))
>  		return 0;
>  
> -	return arm_smmu_init_one_queue(smmu, &smmu->priq.q, ARM_SMMU_PRIQ_PROD,
> -				       ARM_SMMU_PRIQ_CONS, PRIQ_ENT_DWORDS);
> +	return arm_smmu_init_one_queue(smmu, &smmu->priq.q,
> +				       ARM_SMMU_PRIQ_PROD(smmu),
> +				       ARM_SMMU_PRIQ_CONS(smmu),
> +				       PRIQ_ENT_DWORDS);
>  }
>  
>  static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
> @@ -2363,8 +2381,10 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
>  
>  	/* Event queue */
>  	writeq_relaxed(smmu->evtq.q.q_base, smmu->base + ARM_SMMU_EVTQ_BASE);
> -	writel_relaxed(smmu->evtq.q.prod, smmu->base + ARM_SMMU_EVTQ_PROD);
> -	writel_relaxed(smmu->evtq.q.cons, smmu->base + ARM_SMMU_EVTQ_CONS);
> +	writel_relaxed(smmu->evtq.q.prod, smmu->base +
> +		       ARM_SMMU_EVTQ_PROD(smmu));

And correspondingly just use page1_offset_adjust(ARM_SMMU_EVTQ_*, smmu)
explicitly for these writes.

In fact, if all the potential callsites are immediately converting the
offset into an address, then it may be worth just factoring that into
the helper as well, something like:

static inline void __iomem *arm_smmu_page1_fixup(unsigned long offset,
					struct arm_smmu_device *smmu)
{
	if (offset > SZ_64K && ARM_SMMU_PAGE0_REGS_ONLY(smmu))
		offset -= SZ_64K;

	return smmu->base + offset;
}

What do you reckon?

Robin.

> +	writel_relaxed(smmu->evtq.q.cons, smmu->base +
> +		       ARM_SMMU_EVTQ_CONS(smmu));
>  
>  	enables |= CR0_EVTQEN;
>  	ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
> @@ -2379,9 +2399,9 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
>  		writeq_relaxed(smmu->priq.q.q_base,
>  			       smmu->base + ARM_SMMU_PRIQ_BASE);
>  		writel_relaxed(smmu->priq.q.prod,
> -			       smmu->base + ARM_SMMU_PRIQ_PROD);
> +			       smmu->base + ARM_SMMU_PRIQ_PROD(smmu));
>  		writel_relaxed(smmu->priq.q.cons,
> -			       smmu->base + ARM_SMMU_PRIQ_CONS);
> +			       smmu->base + ARM_SMMU_PRIQ_CONS(smmu));
>  
>  		enables |= CR0_PRIQEN;
>  		ret = arm_smmu_write_reg_sync(smmu, enables, ARM_SMMU_CR0,
> @@ -2605,6 +2625,14 @@ static int arm_smmu_device_hw_probe(struct arm_smmu_device *smmu)
>  }
>  
>  #ifdef CONFIG_ACPI
> +static void acpi_smmu_get_options(u32 model, struct arm_smmu_device *smmu)
> +{
> +	if (model == ACPI_IORT_SMMU_V3_CAVIUM_CN99XX)
> +		smmu->options |= ARM_SMMU_OPT_PAGE0_REGS_ONLY;
> +
> +	dev_notice(smmu->dev, "option mask 0x%x\n", smmu->options);
> +}
> +
>  static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
>  				      struct arm_smmu_device *smmu)
>  {
> @@ -2617,6 +2645,8 @@ static int arm_smmu_device_acpi_probe(struct platform_device *pdev,
>  	/* Retrieve SMMUv3 specific data */
>  	iort_smmu = (struct acpi_iort_smmu_v3 *)node->node_data;
>  
> +	acpi_smmu_get_options(iort_smmu->model, smmu);
> +
>  	if (iort_smmu->flags & ACPI_IORT_SMMU_V3_COHACC_OVERRIDE)
>  		smmu->features |= ARM_SMMU_FEAT_COHERENCY;
>  
> @@ -2652,6 +2682,14 @@ static int arm_smmu_device_dt_probe(struct platform_device *pdev,
>  	return ret;
>  }
>  
> +static unsigned long arm_smmu_resource_size(struct arm_smmu_device *smmu)
> +{
> +	if (ARM_SMMU_PAGE0_REGS_ONLY(smmu))
> +		return SZ_64K;
> +	else
> +		return SZ_128K;
> +}
> +
>  static int arm_smmu_device_probe(struct platform_device *pdev)
>  {
>  	int irq, ret;
> @@ -2668,9 +2706,17 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>  	}
>  	smmu->dev = dev;
>  
> +	if (dev->of_node) {
> +		ret = arm_smmu_device_dt_probe(pdev, smmu);
> +	} else {
> +		ret = arm_smmu_device_acpi_probe(pdev, smmu);
> +		if (ret == -ENODEV)
> +			return ret;
> +	}
> +
>  	/* Base address */
>  	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> -	if (resource_size(res) + 1 < SZ_128K) {
> +	if (resource_size(res) + 1 < arm_smmu_resource_size(smmu)) {
>  		dev_err(dev, "MMIO region too small (%pr)\n", res);
>  		return -EINVAL;
>  	}
> @@ -2697,14 +2743,6 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
>  	if (irq > 0)
>  		smmu->gerr_irq = irq;
>  
> -	if (dev->of_node) {
> -		ret = arm_smmu_device_dt_probe(pdev, smmu);
> -	} else {
> -		ret = arm_smmu_device_acpi_probe(pdev, smmu);
> -		if (ret == -ENODEV)
> -			return ret;
> -	}
> -
>  	/* Set bypass mode according to firmware probing result */
>  	bypass = !!ret;
>  
> 

Re: [v4 3/4] iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74

[Linu Cherian]

On Tue May 09, 2017 at 02:02:58PM +0100, Robin Murphy wrote:
> On 09/05/17 12:45, Geetha sowjanya wrote:
> > From: Linu Cherian <linu.cherian@cavium.com>
> > 
> > Cavium ThunderX2 SMMU implementation doesn't support page 1 register space
> > and PAGE0_REGS_ONLY option is enabled as an errata workaround.
> > This option when turned on, replaces all page 1 offsets used for
> > EVTQ_PROD/CONS, PRIQ_PROD/CONS register access with page 0 offsets.
> > 
> > SMMU resource size checks are now based on SMMU option PAGE0_REGS_ONLY,
> > since resource size can be either 64k/128k.
> > For this, arm_smmu_device_dt_probe/acpi_probe has been moved before
> > platform_get_resource call, so that SMMU options are set beforehand.
> > 
> > Signed-off-by: Linu Cherian <linu.cherian@cavium.com>
> > Signed-off-by: Geetha Sowjanya <geethasowjanya.akula@cavium.com>
> > ---
> >  Documentation/arm64/silicon-errata.txt             |  1 +
> >  .../devicetree/bindings/iommu/arm,smmu-v3.txt      |  6 ++
> >  drivers/iommu/arm-smmu-v3.c                        | 80 ++++++++++++++++------
> >  3 files changed, 66 insertions(+), 21 deletions(-)
> > 
> > diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
> > index 10f2ddd..4693a32 100644
> > --- a/Documentation/arm64/silicon-errata.txt
> > +++ b/Documentation/arm64/silicon-errata.txt
> > @@ -62,6 +62,7 @@ stable kernels.
> >  | Cavium         | ThunderX GICv3  | #23154          | CAVIUM_ERRATUM_23154        |
> >  | Cavium         | ThunderX Core   | #27456          | CAVIUM_ERRATUM_27456        |
> >  | Cavium         | ThunderX SMMUv2 | #27704          | N/A                         |
> > +| Cavium         | ThunderX2 SMMUv3| #74             | N/A                         |
> >  |                |                 |                 |                             |
> >  | Freescale/NXP  | LS2080A/LS1043A | A-008585        | FSL_ERRATUM_A008585         |
> >  |                |                 |                 |                             |
> > diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> > index be57550..e6da62b 100644
> > --- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> > +++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> > @@ -49,6 +49,12 @@ the PCIe specification.
> >  - hisilicon,broken-prefetch-cmd
> >                      : Avoid sending CMD_PREFETCH_* commands to the SMMU.
> >  
> > +- cavium-cn99xx,broken-page1-regspace
> > +                    : Replaces all page 1 offsets used for EVTQ_PROD/CONS,
> > +						PRIQ_PROD/CONS register access with page 0 offsets.
> > +						Set for Caviun ThunderX2 silicon that doesn't support
> > +						SMMU page1 register space.
> > +
> >  ** Example
> >  
> >          smmu@2b400000 {
> > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> > index 380969a..1e986a0 100644
> > --- a/drivers/iommu/arm-smmu-v3.c
> > +++ b/drivers/iommu/arm-smmu-v3.c
> > @@ -176,15 +176,15 @@
> >  #define ARM_SMMU_CMDQ_CONS		0x9c
> >  
> >  #define ARM_SMMU_EVTQ_BASE		0xa0
> > -#define ARM_SMMU_EVTQ_PROD		0x100a8
> > -#define ARM_SMMU_EVTQ_CONS		0x100ac
> > +#define ARM_SMMU_EVTQ_PROD(smmu)	(page1_offset_adjust(0x100a8, smmu))
> > +#define ARM_SMMU_EVTQ_CONS(smmu)	(page1_offset_adjust(0x100ac, smmu))
> 
> Sorry, perhaps I should have communicated the rest of the idea more
> explicitly - you now don't need to change these definitions...
> 

Fine. 


> >  #define ARM_SMMU_EVTQ_IRQ_CFG0		0xb0
> >  #define ARM_SMMU_EVTQ_IRQ_CFG1		0xb8
> >  #define ARM_SMMU_EVTQ_IRQ_CFG2		0xbc
> >  
> >  #define ARM_SMMU_PRIQ_BASE		0xc0
> > -#define ARM_SMMU_PRIQ_PROD		0x100c8
> > -#define ARM_SMMU_PRIQ_CONS		0x100cc
> > +#define ARM_SMMU_PRIQ_PROD(smmu)	(page1_offset_adjust(0x100c8, smmu))
> > +#define ARM_SMMU_PRIQ_CONS(smmu)	(page1_offset_adjust(0x100cc, smmu))
> >  #define ARM_SMMU_PRIQ_IRQ_CFG0		0xd0
> >  #define ARM_SMMU_PRIQ_IRQ_CFG1		0xd8
> >  #define ARM_SMMU_PRIQ_IRQ_CFG2		0xdc
> > @@ -412,6 +412,9 @@
> >  #define MSI_IOVA_BASE			0x8000000
> >  #define MSI_IOVA_LENGTH			0x100000
> >  
> > +#define ARM_SMMU_PAGE0_REGS_ONLY(smmu)		\
> > +	((smmu)->options & ARM_SMMU_OPT_PAGE0_REGS_ONLY)
> > +
> >  static bool disable_bypass;
> >  module_param_named(disable_bypass, disable_bypass, bool, S_IRUGO);
> >  MODULE_PARM_DESC(disable_bypass,
> > @@ -597,6 +600,7 @@ struct arm_smmu_device {
> >  	u32				features;
> >  
> >  #define ARM_SMMU_OPT_SKIP_PREFETCH	(1 << 0)
> > +#define ARM_SMMU_OPT_PAGE0_REGS_ONLY    (1 << 1)
> >  	u32				options;
> >  
> >  	struct arm_smmu_cmdq		cmdq;
> > @@ -663,9 +667,19 @@ struct arm_smmu_option_prop {
> >  
> >  static struct arm_smmu_option_prop arm_smmu_options[] = {
> >  	{ ARM_SMMU_OPT_SKIP_PREFETCH, "hisilicon,broken-prefetch-cmd" },
> > +	{ ARM_SMMU_OPT_PAGE0_REGS_ONLY, "cavium-cn99xx,broken-page1-regspace"},
> >  	{ 0, NULL},
> >  };
> >  
> > +static inline unsigned long page1_offset_adjust(
> > +	unsigned long off, struct arm_smmu_device *smmu)
> > +{
> > +	if (off > SZ_64K && ARM_SMMU_PAGE0_REGS_ONLY(smmu))
> > +		return (off - SZ_64K);
> > +
> > +	return off;
> > +}
> > +
> >  static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
> >  {
> >  	return container_of(dom, struct arm_smmu_domain, domain);
> > @@ -1986,8 +2000,10 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
> >  		return ret;
> >  
> >  	/* evtq */
> > -	ret = arm_smmu_init_one_queue(smmu, &smmu->evtq.q, ARM_SMMU_EVTQ_PROD,
> > -				      ARM_SMMU_EVTQ_CONS, EVTQ_ENT_DWORDS);
> > +	ret = arm_smmu_init_one_queue(smmu, &smmu->evtq.q,
> > +				      ARM_SMMU_EVTQ_PROD(smmu),
> > +				      ARM_SMMU_EVTQ_CONS(smmu),
> > +				      EVTQ_ENT_DWORDS);
> 
> ...or these callsites; you can just use page1_offset_adjust() directly
> within arm_smmu_init_one_queue(), i.e.

> 
> 
>        q->prod_reg = smmu->base + page1_offset_adjust(prod_off, smmu);
>        q->cons_reg = smmu->base + page1_offset_adjust(cons_off, smmu);
> 
> because it won't affect page 0 offsets either way.
> 
> >  	if (ret)
> >  		return ret;
> >  
> > @@ -1995,8 +2011,10 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
> >  	if (!(smmu->features & ARM_SMMU_FEAT_PRI))
> >  		return 0;
> >  
> > -	return arm_smmu_init_one_queue(smmu, &smmu->priq.q, ARM_SMMU_PRIQ_PROD,
> > -				       ARM_SMMU_PRIQ_CONS, PRIQ_ENT_DWORDS);
> > +	return arm_smmu_init_one_queue(smmu, &smmu->priq.q,
> > +				       ARM_SMMU_PRIQ_PROD(smmu),
> > +				       ARM_SMMU_PRIQ_CONS(smmu),
> > +				       PRIQ_ENT_DWORDS);
> >  }
> >  
> >  static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
> > @@ -2363,8 +2381,10 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
> >  
> >  	/* Event queue */
> >  	writeq_relaxed(smmu->evtq.q.q_base, smmu->base + ARM_SMMU_EVTQ_BASE);
> > -	writel_relaxed(smmu->evtq.q.prod, smmu->base + ARM_SMMU_EVTQ_PROD);
> > -	writel_relaxed(smmu->evtq.q.cons, smmu->base + ARM_SMMU_EVTQ_CONS);
> > +	writel_relaxed(smmu->evtq.q.prod, smmu->base +
> > +		       ARM_SMMU_EVTQ_PROD(smmu));
> 
> And correspondingly just use page1_offset_adjust(ARM_SMMU_EVTQ_*, smmu)
> explicitly for these writes.
> 
> In fact, if all the potential callsites are immediately converting the
> offset into an address, then it may be worth just factoring that into
> the helper as well, something like:
> 
> static inline void __iomem *arm_smmu_page1_fixup(unsigned long offset,
> 					struct arm_smmu_device *smmu)
> {
> 	if (offset > SZ_64K && ARM_SMMU_PAGE0_REGS_ONLY(smmu))
> 		offset -= SZ_64K;
> 
> 	return smmu->base + offset;
> }
> 
> What do you reckon?
> 

Just had a opinion that, replacing all page1 offset macros(ARM_SMMU_EVTQ/PRIQ_PROD/CONS) with
page1_offset_adjust(ARM_SMMU_EVTQ/PRIQ_PROD/CONS, smmu) will make the changes 
more uniform. In that case, we wont need, offset > SZ_64K  check as
well.

Hope the intention is not to change the offset definitions.


-- 
Linu cherian

Re: [v4 3/4] iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #74

[Linu Cherian]

> On Tue May 09, 2017 at 02:02:58PM +0100, Robin Murphy wrote:
> > On 09/05/17 12:45, Geetha sowjanya wrote:
> > > From: Linu Cherian <linu.cherian@cavium.com>
> > > 
> > > Cavium ThunderX2 SMMU implementation doesn't support page 1 register space
> > > and PAGE0_REGS_ONLY option is enabled as an errata workaround.
> > > This option when turned on, replaces all page 1 offsets used for
> > > EVTQ_PROD/CONS, PRIQ_PROD/CONS register access with page 0 offsets.
> > > 
> > > SMMU resource size checks are now based on SMMU option PAGE0_REGS_ONLY,
> > > since resource size can be either 64k/128k.
> > > For this, arm_smmu_device_dt_probe/acpi_probe has been moved before
> > > platform_get_resource call, so that SMMU options are set beforehand.
> > > 
> > > Signed-off-by: Linu Cherian <linu.cherian@cavium.com>
> > > Signed-off-by: Geetha Sowjanya <geethasowjanya.akula@cavium.com>
> > > ---
> > >  Documentation/arm64/silicon-errata.txt             |  1 +
> > >  .../devicetree/bindings/iommu/arm,smmu-v3.txt      |  6 ++
> > >  drivers/iommu/arm-smmu-v3.c                        | 80 ++++++++++++++++------
> > >  3 files changed, 66 insertions(+), 21 deletions(-)
> > > 
> > > diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
> > > index 10f2ddd..4693a32 100644
> > > --- a/Documentation/arm64/silicon-errata.txt
> > > +++ b/Documentation/arm64/silicon-errata.txt
> > > @@ -62,6 +62,7 @@ stable kernels.
> > >  | Cavium         | ThunderX GICv3  | #23154          | CAVIUM_ERRATUM_23154        |
> > >  | Cavium         | ThunderX Core   | #27456          | CAVIUM_ERRATUM_27456        |
> > >  | Cavium         | ThunderX SMMUv2 | #27704          | N/A                         |
> > > +| Cavium         | ThunderX2 SMMUv3| #74             | N/A                         |
> > >  |                |                 |                 |                             |
> > >  | Freescale/NXP  | LS2080A/LS1043A | A-008585        | FSL_ERRATUM_A008585         |
> > >  |                |                 |                 |                             |
> > > diff --git a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> > > index be57550..e6da62b 100644
> > > --- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> > > +++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
> > > @@ -49,6 +49,12 @@ the PCIe specification.
> > >  - hisilicon,broken-prefetch-cmd
> > >                      : Avoid sending CMD_PREFETCH_* commands to the SMMU.
> > >  
> > > +- cavium-cn99xx,broken-page1-regspace
> > > +                    : Replaces all page 1 offsets used for EVTQ_PROD/CONS,
> > > +						PRIQ_PROD/CONS register access with page 0 offsets.
> > > +						Set for Caviun ThunderX2 silicon that doesn't support
> > > +						SMMU page1 register space.
> > > +
> > >  ** Example
> > >  
> > >          smmu@2b400000 {
> > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> > > index 380969a..1e986a0 100644
> > > --- a/drivers/iommu/arm-smmu-v3.c
> > > +++ b/drivers/iommu/arm-smmu-v3.c
> > > @@ -176,15 +176,15 @@
> > >  #define ARM_SMMU_CMDQ_CONS		0x9c
> > >  
> > >  #define ARM_SMMU_EVTQ_BASE		0xa0
> > > -#define ARM_SMMU_EVTQ_PROD		0x100a8
> > > -#define ARM_SMMU_EVTQ_CONS		0x100ac
> > > +#define ARM_SMMU_EVTQ_PROD(smmu)	(page1_offset_adjust(0x100a8, smmu))
> > > +#define ARM_SMMU_EVTQ_CONS(smmu)	(page1_offset_adjust(0x100ac, smmu))
> > 
> > Sorry, perhaps I should have communicated the rest of the idea more
> > explicitly - you now don't need to change these definitions...
> > 
> 
> Fine. 
> 
> 
> > >  #define ARM_SMMU_EVTQ_IRQ_CFG0		0xb0
> > >  #define ARM_SMMU_EVTQ_IRQ_CFG1		0xb8
> > >  #define ARM_SMMU_EVTQ_IRQ_CFG2		0xbc
> > >  
> > >  #define ARM_SMMU_PRIQ_BASE		0xc0
> > > -#define ARM_SMMU_PRIQ_PROD		0x100c8
> > > -#define ARM_SMMU_PRIQ_CONS		0x100cc
> > > +#define ARM_SMMU_PRIQ_PROD(smmu)	(page1_offset_adjust(0x100c8, smmu))
> > > +#define ARM_SMMU_PRIQ_CONS(smmu)	(page1_offset_adjust(0x100cc, smmu))
> > >  #define ARM_SMMU_PRIQ_IRQ_CFG0		0xd0
> > >  #define ARM_SMMU_PRIQ_IRQ_CFG1		0xd8
> > >  #define ARM_SMMU_PRIQ_IRQ_CFG2		0xdc
> > > @@ -412,6 +412,9 @@
> > >  #define MSI_IOVA_BASE			0x8000000
> > >  #define MSI_IOVA_LENGTH			0x100000
> > >  
> > > +#define ARM_SMMU_PAGE0_REGS_ONLY(smmu)		\
> > > +	((smmu)->options & ARM_SMMU_OPT_PAGE0_REGS_ONLY)
> > > +
> > >  static bool disable_bypass;
> > >  module_param_named(disable_bypass, disable_bypass, bool, S_IRUGO);
> > >  MODULE_PARM_DESC(disable_bypass,
> > > @@ -597,6 +600,7 @@ struct arm_smmu_device {
> > >  	u32				features;
> > >  
> > >  #define ARM_SMMU_OPT_SKIP_PREFETCH	(1 << 0)
> > > +#define ARM_SMMU_OPT_PAGE0_REGS_ONLY    (1 << 1)
> > >  	u32				options;
> > >  
> > >  	struct arm_smmu_cmdq		cmdq;
> > > @@ -663,9 +667,19 @@ struct arm_smmu_option_prop {
> > >  
> > >  static struct arm_smmu_option_prop arm_smmu_options[] = {
> > >  	{ ARM_SMMU_OPT_SKIP_PREFETCH, "hisilicon,broken-prefetch-cmd" },
> > > +	{ ARM_SMMU_OPT_PAGE0_REGS_ONLY, "cavium-cn99xx,broken-page1-regspace"},
> > >  	{ 0, NULL},
> > >  };
> > >  
> > > +static inline unsigned long page1_offset_adjust(
> > > +	unsigned long off, struct arm_smmu_device *smmu)
> > > +{
> > > +	if (off > SZ_64K && ARM_SMMU_PAGE0_REGS_ONLY(smmu))
> > > +		return (off - SZ_64K);
> > > +
> > > +	return off;
> > > +}
> > > +
> > >  static struct arm_smmu_domain *to_smmu_domain(struct iommu_domain *dom)
> > >  {
> > >  	return container_of(dom, struct arm_smmu_domain, domain);
> > > @@ -1986,8 +2000,10 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
> > >  		return ret;
> > >  
> > >  	/* evtq */
> > > -	ret = arm_smmu_init_one_queue(smmu, &smmu->evtq.q, ARM_SMMU_EVTQ_PROD,
> > > -				      ARM_SMMU_EVTQ_CONS, EVTQ_ENT_DWORDS);
> > > +	ret = arm_smmu_init_one_queue(smmu, &smmu->evtq.q,
> > > +				      ARM_SMMU_EVTQ_PROD(smmu),
> > > +				      ARM_SMMU_EVTQ_CONS(smmu),
> > > +				      EVTQ_ENT_DWORDS);
> > 
> > ...or these callsites; you can just use page1_offset_adjust() directly
> > within arm_smmu_init_one_queue(), i.e.
> 
> > 
> > 
> >        q->prod_reg = smmu->base + page1_offset_adjust(prod_off, smmu);
> >        q->cons_reg = smmu->base + page1_offset_adjust(cons_off, smmu);
> > 
> > because it won't affect page 0 offsets either way.
> > 
> > >  	if (ret)
> > >  		return ret;
> > >  
> > > @@ -1995,8 +2011,10 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
> > >  	if (!(smmu->features & ARM_SMMU_FEAT_PRI))
> > >  		return 0;
> > >  
> > > -	return arm_smmu_init_one_queue(smmu, &smmu->priq.q, ARM_SMMU_PRIQ_PROD,
> > > -				       ARM_SMMU_PRIQ_CONS, PRIQ_ENT_DWORDS);
> > > +	return arm_smmu_init_one_queue(smmu, &smmu->priq.q,
> > > +				       ARM_SMMU_PRIQ_PROD(smmu),
> > > +				       ARM_SMMU_PRIQ_CONS(smmu),
> > > +				       PRIQ_ENT_DWORDS);
> > >  }
> > >  
> > >  static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
> > > @@ -2363,8 +2381,10 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
> > >  
> > >  	/* Event queue */
> > >  	writeq_relaxed(smmu->evtq.q.q_base, smmu->base + ARM_SMMU_EVTQ_BASE);
> > > -	writel_relaxed(smmu->evtq.q.prod, smmu->base + ARM_SMMU_EVTQ_PROD);
> > > -	writel_relaxed(smmu->evtq.q.cons, smmu->base + ARM_SMMU_EVTQ_CONS);
> > > +	writel_relaxed(smmu->evtq.q.prod, smmu->base +
> > > +		       ARM_SMMU_EVTQ_PROD(smmu));
> > 
> > And correspondingly just use page1_offset_adjust(ARM_SMMU_EVTQ_*, smmu)
> > explicitly for these writes.
> > 
> > In fact, if all the potential callsites are immediately converting the
> > offset into an address, then it may be worth just factoring that into
> > the helper as well, something like:
> > 
> > static inline void __iomem *arm_smmu_page1_fixup(unsigned long offset,
> > 					struct arm_smmu_device *smmu)
> > {
> > 	if (offset > SZ_64K && ARM_SMMU_PAGE0_REGS_ONLY(smmu))
> > 		offset -= SZ_64K;
> > 
> > 	return smmu->base + offset;
> > }
> > 
> > What do you reckon?
> > 
> 
> Just had a opinion that, replacing all page1 offset macros(ARM_SMMU_EVTQ/PRIQ_PROD/CONS) with
> page1_offset_adjust(ARM_SMMU_EVTQ/PRIQ_PROD/CONS, smmu) will make the changes 
> more uniform. In that case, we wont need, offset > SZ_64K  check as
> well.
> 
> Hope the intention is not to change the offset definitions.
> 
> 

Will post v5 series with the approach you suggested (using
arm_smmu_page1_fixup). Also realize that this will result in less
number of changes as well.

Thanks.


-- 
Linu cherian