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

From: Geetha sowjanya
Date: Thu Apr 27 2017 - 08:05:59 EST


From: Geetha <gakula@xxxxxxxxxx>

Cavium 99xx 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 <gakula@xxxxxxxxxx>
---
Documentation/arm64/silicon-errata.txt | 1 +
drivers/iommu/arm-smmu-v3.c | 32 ++++++++++++++++++++++++++++----
2 files changed, 29 insertions(+), 4 deletions(-)

diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt
index 629e2ce..cc15f25 100644
--- a/Documentation/arm64/silicon-errata.txt
+++ b/Documentation/arm64/silicon-errata.txt
@@ -62,6 +62,7 @@ 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 ee23ccd..eb55d38 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -2211,10 +2211,30 @@ 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 0;
+}
+
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;
+ u32 irqflags = 0;

/* Disable IRQs first */
ret = arm_smmu_write_reg_sync(smmu, 0, ARM_SMMU_IRQ_CTRL,
@@ -2229,9 +2249,10 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
/* Request interrupt lines */
irq = smmu->evtq.q.irq;
if (irq) {
+ irqflags = get_irq_flags(smmu, irq);
ret = devm_request_threaded_irq(smmu->dev, irq, NULL,
arm_smmu_evtq_thread,
- IRQF_ONESHOT,
+ IRQF_ONESHOT | irqflags,
"arm-smmu-v3-evtq", smmu);
if (ret < 0)
dev_warn(smmu->dev, "failed to enable evtq irq\n");
@@ -2239,8 +2260,9 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)

irq = smmu->cmdq.q.irq;
if (irq) {
+ irqflags = get_irq_flags(smmu, irq);
ret = devm_request_irq(smmu->dev, irq,
- arm_smmu_cmdq_sync_handler, 0,
+ arm_smmu_cmdq_sync_handler, irqflags,
"arm-smmu-v3-cmdq-sync", smmu);
if (ret < 0)
dev_warn(smmu->dev, "failed to enable cmdq-sync irq\n");
@@ -2248,8 +2270,9 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)

irq = smmu->gerr_irq;
if (irq) {
+ irqflags = get_irq_flags(smmu, irq);
ret = devm_request_irq(smmu->dev, irq, arm_smmu_gerror_handler,
- 0, "arm-smmu-v3-gerror", smmu);
+ irqflags, "arm-smmu-v3-gerror", smmu);
if (ret < 0)
dev_warn(smmu->dev, "failed to enable gerror irq\n");
}
@@ -2257,9 +2280,10 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
if (smmu->features & ARM_SMMU_FEAT_PRI) {
irq = smmu->priq.q.irq;
if (irq) {
+ irqflags = get_irq_flags(smmu, irq);
ret = devm_request_threaded_irq(smmu->dev, irq, NULL,
arm_smmu_priq_thread,
- IRQF_ONESHOT,
+ IRQF_ONESHOT | irqflags,
"arm-smmu-v3-priq",
smmu);
if (ret < 0)
--
1.9.1