[PATCH v2 4/4] perf/smmuv3: Add MSI irq support

From: Shameer Kolothum
Date: Tue Jul 24 2018 - 07:46:43 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 | 105 +++++++++++++++++++++++++++++++++---------
1 file changed, 84 insertions(+), 21 deletions(-)

diff --git a/drivers/perf/arm_smmuv3_pmu.c b/drivers/perf/arm_smmuv3_pmu.c
index b3dc394..ca69813 100644
--- a/drivers/perf/arm_smmuv3_pmu.c
+++ b/drivers/perf/arm_smmuv3_pmu.c
@@ -94,6 +94,10 @@
#define SMMU_PMCG_IRQ_CFG2 0xE64
#define SMMU_PMCG_IRQ_STATUS 0xE68

+/* MSI config fields */
+#define MSI_CFG0_ADDR_MASK GENMASK_ULL(51, 2)
+#define MSI_CFG2_MEMATTR_DEVICE_nGnRE 0x1
+
#define SMMU_COUNTER_RELOAD BIT(31)
#define SMMU_DEFAULT_FILTER_SEC 0
#define SMMU_DEFAULT_FILTER_SPAN 1
@@ -657,14 +661,89 @@ 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)
+{
+ 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,
+ IRQF_NOBALANCING | IRQF_SHARED | IRQF_NO_THREAD,
+ "smmu-v3-pmu", pmu);
+ return ret;
+}
+
static int smmu_pmu_reset(struct smmu_pmu *smmu_pmu)
{
+ int ret;
+
/* Disable counter and interrupt */
writeq(smmu_pmu->counter_present_mask,
smmu_pmu->reg_base + SMMU_PMCG_CNTENCLR0);
writeq(smmu_pmu->counter_present_mask,
smmu_pmu->reg_base + SMMU_PMCG_INTENCLR0);

+ ret = smmu_pmu_setup_irq(smmu_pmu);
+ if (ret) {
+ dev_err(smmu_pmu->dev, "failed to setup irqs\n");
+ return ret;
+ }
+
+ /* Pick one CPU to be the preferred one to use */
+ smmu_pmu->on_cpu = smp_processor_id();
+ WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(smmu_pmu->on_cpu)));
+
smmu_pmu_disable(&smmu_pmu->pmu);
return 0;
}
@@ -738,26 +817,8 @@ static int smmu_pmu_probe(struct platform_device *pdev)
}

irq = platform_get_irq(pdev, 0);
- if (irq < 0) {
- dev_err(dev, "Failed to get valid irq for smmu @%pa\n",
- &mem_resource_0->start);
- return irq;
- }
-
- err = devm_request_irq(dev, irq, smmu_pmu_handle_irq,
- IRQF_NOBALANCING | IRQF_SHARED | IRQF_NO_THREAD,
- "smmu-pmu", smmu_pmu);
- if (err) {
- dev_err(dev,
- "Unable to request IRQ%d for SMMU PMU counters\n", irq);
- return err;
- }
-
- smmu_pmu->irq = irq;
-
- /* Pick one CPU to be the preferred one to use */
- smmu_pmu->on_cpu = smp_processor_id();
- WARN_ON(irq_set_affinity(smmu_pmu->irq, cpumask_of(smmu_pmu->on_cpu)));
+ if (irq > 0)
+ smmu_pmu->irq = irq;

smmu_pmu->num_counters = get_num_counters(smmu_pmu);
smmu_pmu->counter_present_mask = GENMASK(smmu_pmu->num_counters - 1, 0);
@@ -765,7 +826,9 @@ static int smmu_pmu_probe(struct platform_device *pdev)
SMMU_PMCG_CFGR_SIZE_MASK) >> SMMU_PMCG_CFGR_SIZE_SHIFT;
smmu_pmu->counter_mask = GENMASK_ULL(reg_size, 0);

- smmu_pmu_reset(smmu_pmu);
+ err = smmu_pmu_reset(smmu_pmu);
+ if (err)
+ return err;

err = cpuhp_state_add_instance_nocalls(cpuhp_state_num,
&smmu_pmu->node);
--
2.7.4