iommu/arm-smmu-v3: Add workaround for Cavium ThunderX2 erratum #126
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.
Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Geetha sowjanya <gakula@caviumnetworks.com>
[will: reworked irq equality checking and added SPI check]
Signed-off-by: Will Deacon <will.deacon@arm.com>
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index a8ebda9..83d65d9 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -833,6 +833,24 @@ 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 false;
+
+ /*
+ * ThunderX2 doesn't support MSIs from the SMMU, so we're checking
+ * SPI numbers here.
+ */
+ return smmu->event_gsiv == smmu->pri_gsiv &&
+ smmu->event_gsiv == smmu->gerr_gsiv &&
+ smmu->event_gsiv == smmu->sync_gsiv;
+}
+
static unsigned long arm_smmu_v3_resource_size(struct acpi_iort_smmu_v3 *smmu)
{
/*
@@ -860,26 +878,33 @@ static void __init arm_smmu_v3_init_resources(struct resource *res,
res[num_res].flags = IORESOURCE_MEM;
num_res++;
+ if (arm_smmu_v3_is_combined_irq(smmu)) {
+ if (smmu->event_gsiv)
+ 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->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->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->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++]);
+ 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)