[PATCH v3 3/3] perf/smmuv3: Add MSI irq support

From: Shameer Kolothum
Date: Fri Sep 21 2018 - 11:10:02 EST


This adds support for MSI-based counter overflow interrupt.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@xxxxxxxxxx>
---
drivers/perf/arm_smmuv3_pmu.c | 58 +++++++++++++++++++++++++++++++++++++++++++
1 file changed, 58 insertions(+)

diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
index 2fa6c96..84f7907 100644
--- a/drivers/perf/arm_smmuv3_pmu.c
+++ b/drivers/perf/arm_smmuv3_pmu.c
@@ -57,6 +57,7 @@
#define SMMU_PMCG_OVSSET0 0xCC0
#define SMMU_PMCG_CFGR 0xE00
#define SMMU_PMCG_CFGR_RELOC_CTRS BIT(20)
+#define SMMU_PMCG_CFGR_MSI BIT(21)
#define SMMU_PMCG_CFGR_SIZE_MASK GENMASK(13, 8)
#define SMMU_PMCG_CFGR_NCTR_MASK GENMASK(5, 0)
#define SMMU_PMCG_CR 0xE04
@@ -66,6 +67,12 @@
#define SMMU_PMCG_IRQ_CTRL 0xE50
#define SMMU_PMCG_IRQ_CTRL_IRQEN BIT(0)
#define SMMU_PMCG_IRQ_CFG0 0xE58
+#define SMMU_PMCG_IRQ_CFG1 0xE60
+#define SMMU_PMCG_IRQ_CFG2 0xE64
+
+/* MSI config fields */
+#define MSI_CFG0_ADDR_MASK GENMASK_ULL(51, 2)
+#define MSI_CFG2_MEMATTR_DEVICE_nGnRE 0x1

#define SMMU_DEFAULT_FILTER_SPAN 1
#define SMMU_DEFAULT_FILTER_STREAM_ID GENMASK(31, 0)
@@ -548,11 +555,62 @@ static irqreturn_t smmu_pmu_handle_irq(int irq_num, void *data)
return IRQ_HANDLED;
}

+static void smmu_pmu_free_msis(void *data)
+{
+ struct device *dev = data;
+
+ platform_msi_domain_free_irqs(dev);
+}
+
+static void smmu_pmu_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
+{
+ phys_addr_t doorbell;
+ struct device *dev = msi_desc_to_dev(desc);
+ struct smmu_pmu *pmu = dev_get_drvdata(dev);
+
+ doorbell = (((u64)msg->address_hi) << 32) | msg->address_lo;
+ doorbell &= MSI_CFG0_ADDR_MASK;
+
+ writeq_relaxed(doorbell, pmu->reg_base + SMMU_PMCG_IRQ_CFG0);
+ writel_relaxed(msg->data, pmu->reg_base + SMMU_PMCG_IRQ_CFG1);
+ writel_relaxed(MSI_CFG2_MEMATTR_DEVICE_nGnRE,
+ pmu->reg_base + SMMU_PMCG_IRQ_CFG2);
+}
+
+static void smmu_pmu_setup_msi(struct smmu_pmu *pmu)
+{
+ struct msi_desc *desc;
+ struct device *dev = pmu->dev;
+ int ret;
+
+ /* Clear MSI address reg */
+ writeq_relaxed(0, pmu->reg_base + SMMU_PMCG_IRQ_CFG0);
+
+ /* MSI supported or not */
+ if (!(readl(pmu->reg_base + SMMU_PMCG_CFGR) & SMMU_PMCG_CFGR_MSI))
+ return;
+
+ ret = platform_msi_domain_alloc_irqs(dev, 1, smmu_pmu_write_msi_msg);
+ if (ret) {
+ dev_warn(dev, "failed to allocate MSIs\n");
+ return;
+ }
+
+ desc = first_msi_entry(dev);
+ if (desc)
+ pmu->irq = desc->irq;
+
+ /* Add callback to free MSIs on teardown */
+ devm_add_action(dev, smmu_pmu_free_msis, dev);
+}
+
static int smmu_pmu_setup_irq(struct smmu_pmu *pmu)
{
unsigned long flags = IRQF_NOBALANCING | IRQF_SHARED | IRQF_NO_THREAD;
int irq, ret = -ENXIO;

+ smmu_pmu_setup_msi(pmu);
+
irq = pmu->irq;
if (irq)
ret = devm_request_irq(pmu->dev, irq, smmu_pmu_handle_irq,
--
2.7.4