[PATCH v9 3/3] iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126

Geetha sowjanya
2017-06-22T12:26:24Z

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.

New named irq "combined" is set as a errata workaround, which allows to
share the irq line by register single irq handler for all the interrupts.

Signed-off-by: Geetha sowjanya <gakula@caviumnetworks.com>
---
Documentation/arm64/silicon-errata.txt | 1 +
.../devicetree/bindings/iommu/arm,smmu-v3.txt | 1 +
drivers/acpi/arm64/iort.c | 54 +++++++----
drivers/iommu/arm-smmu-v3.c | 105 +++++++++++++++-----
4 files changed, 116 insertions(+), 45 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/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
index 6ecc48c..a5a1ca4 100644
--- a/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
+++ b/Documentation/devicetree/bindings/iommu/arm,smmu-v3.txt
@@ -26,6 +26,7 @@ the PCIe specification.
* "priq" - PRI Queue not empty
* "cmdq-sync" - CMD_SYNC complete
* "gerror" - Global Error activated
+ * "combined" - Handles above all 4 interrupts.

- #iommu-cells : See the generic IOMMU binding described in
devicetree/bindings/pci/pci-iommu.txt
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index c166f3e..43e1f13 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -828,6 +828,18 @@ static int __init arm_smmu_v3_count_resources(struct acpi_iort_node *node)
return num_res;
}

+static bool arm_smmu_v3_is_combined_irq(struct acpi_iort_smmu_v3 *smmu)
+{
+ /*
+ * Cavium ThunderX2 implementation doesn't not support unique
+ * irq line. Use single irq line for all the SMMUv3 interrupts.
+ */
+ if (smmu->model == ACPI_IORT_SMMU_V3_CAVIUM_CN99XX)
+ return true;
+
+ return false;
+}
+
static unsigned long arm_smmu_v3_resource_size(struct acpi_iort_smmu_v3 *smmu)
{
/*
@@ -855,26 +867,32 @@ static void __init arm_smmu_v3_init_resources(struct resource *res,
res[num_res].flags = IORESOURCE_MEM;

num_res++;
-
- if (smmu->event_gsiv)
- acpi_iort_register_irq(smmu->event_gsiv, "eventq",
- ACPI_EDGE_SENSITIVE,
- &res[num_res++]);
-
- if (smmu->pri_gsiv)
- acpi_iort_register_irq(smmu->pri_gsiv, "priq",
- ACPI_EDGE_SENSITIVE,
- &res[num_res++]);
-
- if (smmu->gerr_gsiv)
- acpi_iort_register_irq(smmu->gerr_gsiv, "gerror",
- ACPI_EDGE_SENSITIVE,
- &res[num_res++]);
-
- if (smmu->sync_gsiv)
- acpi_iort_register_irq(smmu->sync_gsiv, "cmdq-sync",
+ if (arm_smmu_v3_is_combined_irq(smmu))
+ acpi_iort_register_irq(smmu->event_gsiv, "combined",
ACPI_EDGE_SENSITIVE,
&res[num_res++]);
+ else {
+
+ if (smmu->event_gsiv)
+ acpi_iort_register_irq(smmu->event_gsiv, "eventq",
+ ACPI_EDGE_SENSITIVE,
+ &res[num_res++]);
+
+ if (smmu->pri_gsiv)
+ acpi_iort_register_irq(smmu->pri_gsiv, "priq",
+ ACPI_EDGE_SENSITIVE,
+ &res[num_res++]);
+
+ if (smmu->gerr_gsiv)
+ acpi_iort_register_irq(smmu->gerr_gsiv, "gerror",
+ ACPI_EDGE_SENSITIVE,
+ &res[num_res++]);
+
+ if (smmu->sync_gsiv)
+ acpi_iort_register_irq(smmu->sync_gsiv, "cmdq-sync",
+ ACPI_EDGE_SENSITIVE,
+ &res[num_res++]);
+ }
}

static bool __init arm_smmu_v3_is_coherent(struct acpi_iort_node *node)
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 2dea4a9..0f83f7d 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -605,6 +605,7 @@ struct arm_smmu_device {
struct arm_smmu_priq priq;

int gerr_irq;
+ int combined_irq;

unsigned long ias; /* IPA */
unsigned long oas; /* PA */
@@ -1314,6 +1315,29 @@ static irqreturn_t arm_smmu_gerror_handler(int irq, void *dev)
return IRQ_HANDLED;
}

+static irqreturn_t arm_smmu_combined_irq_thread(int irq, void *dev)
+{
+ struct arm_smmu_device *smmu = dev;
+
+ arm_smmu_evtq_thread(irq, dev);
+ if (smmu->features & ARM_SMMU_FEAT_PRI)
+ arm_smmu_priq_thread(irq, dev);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t arm_smmu_combined_irq_handler(int irq, void *dev)
+{
+ irqreturn_t ret;
+
+ ret = arm_smmu_gerror_handler(irq, dev);
+ if (ret == IRQ_NONE) {
+ arm_smmu_cmdq_sync_handler(irq, dev);
+ return IRQ_WAKE_THREAD;
+ }
+ return ret;
+}
+
/* IO_PGTABLE API */
static void __arm_smmu_tlb_sync(struct arm_smmu_device *smmu)
{
@@ -2230,18 +2254,9 @@ static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
devm_add_action(dev, arm_smmu_free_msis, dev);
}

-static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
+static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
{
- int ret, irq;
- u32 irqen_flags = IRQ_CTRL_EVTQ_IRQEN | IRQ_CTRL_GERROR_IRQEN;
-
- /* Disable IRQs first */
- ret = arm_smmu_write_reg_sync(smmu, 0, ARM_SMMU_IRQ_CTRL,
- ARM_SMMU_IRQ_CTRLACK);
- if (ret) {
- dev_err(smmu->dev, "failed to disable irqs\n");
- return ret;
- }
+ int irq, ret;

arm_smmu_setup_msis(smmu);

@@ -2284,10 +2299,41 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
if (ret < 0)
dev_warn(smmu->dev,
"failed to enable priq irq\n");
- else
- irqen_flags |= IRQ_CTRL_PRIQ_IRQEN;
}
}
+}
+
+static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
+{
+ int ret, irq;
+ u32 irqen_flags = IRQ_CTRL_EVTQ_IRQEN | IRQ_CTRL_GERROR_IRQEN;
+
+ /* Disable IRQs first */
+ ret = arm_smmu_write_reg_sync(smmu, 0, ARM_SMMU_IRQ_CTRL,
+ ARM_SMMU_IRQ_CTRLACK);
+ if (ret) {
+ dev_err(smmu->dev, "failed to disable irqs\n");
+ return ret;
+ }
+
+ irq = smmu->combined_irq;
+ if (irq) {
+ /*
+ * Cavium ThunderX2 implementation doesn't not support unique
+ * irq lines. Use single irq line for all the SMMUv3 interrupts.
+ */
+ ret = devm_request_threaded_irq(smmu->dev, irq,
+ arm_smmu_combined_irq_handler,
+ arm_smmu_combined_irq_thread,
+ IRQF_ONESHOT,
+ "arm-smmu-v3-combined-irq", smmu);
+ if (ret < 0)
+ dev_warn(smmu->dev, "failed to enable combined irq\n");
+ } else
+ arm_smmu_setup_unique_irqs(smmu);
+
+ if (smmu->features & ARM_SMMU_FEAT_PRI)
+ irqen_flags |= IRQ_CTRL_PRIQ_IRQEN;

/* Enable interrupt generation on the SMMU */
ret = arm_smmu_write_reg_sync(smmu, irqen_flags,
@@ -2724,22 +2770,27 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
return PTR_ERR(smmu->base);

/* Interrupt lines */
- irq = platform_get_irq_byname(pdev, "eventq");
- if (irq > 0)
- smmu->evtq.q.irq = irq;

- irq = platform_get_irq_byname(pdev, "priq");
+ irq = platform_get_irq_byname(pdev, "combined");
if (irq > 0)
- smmu->priq.q.irq = irq;
+ smmu->combined_irq = irq;
+ else {
+ irq = platform_get_irq_byname(pdev, "eventq");
+ if (irq > 0)
+ smmu->evtq.q.irq = irq;

- irq = platform_get_irq_byname(pdev, "cmdq-sync");
- if (irq > 0)
- smmu->cmdq.q.irq = irq;
+ irq = platform_get_irq_byname(pdev, "priq");
+ if (irq > 0)
+ smmu->priq.q.irq = irq;

- irq = platform_get_irq_byname(pdev, "gerror");
- if (irq > 0)
- smmu->gerr_irq = irq;
+ irq = platform_get_irq_byname(pdev, "cmdq-sync");
+ if (irq > 0)
+ smmu->cmdq.q.irq = irq;

+ irq = platform_get_irq_byname(pdev, "gerror");
+ if (irq > 0)
+ smmu->gerr_irq = irq;
+ }
/* Probe the h/w */
ret = arm_smmu_device_hw_probe(smmu);
if (ret)
--
1.7.1