[PATCH 3/3] iommu/arm-smmu-v3: support suspend/resume

["Peng Fan (OSS)" <peng.fan@oss.nxp.com>]

From: Peng Fan <peng.fan@nxp.com>

smmu maybe power-gated, and the registers are cleared. So
need to restore its registers with arm_smmu_device_reset and
resume the msi interrupt settings in resume callback.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 71 ++++++++++++++++++++++++++---
 1 file changed, 64 insertions(+), 7 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index a8a569573c2f..2bfe4b3d0ba1 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3396,6 +3396,36 @@ static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
 	devm_add_action(dev, arm_smmu_free_msis, dev);
 }
 
+static void arm_smmu_resume_unique_irqs(struct arm_smmu_device *smmu)
+{
+	struct device *dev = smmu->dev;
+	struct msi_desc *desc;
+	struct msi_msg msg;
+
+	if (!dev->msi.domain)
+		return;
+
+	desc = irq_get_msi_desc(smmu->evtq.q.irq);
+	if (desc) {
+		get_cached_msi_msg(smmu->evtq.q.irq, &msg);
+		arm_smmu_write_msi_msg(desc, &msg);
+	}
+
+	desc = irq_get_msi_desc(smmu->gerr_irq);
+	if (desc) {
+		get_cached_msi_msg(smmu->gerr_irq, &msg);
+		arm_smmu_write_msi_msg(desc, &msg);
+	}
+
+	if (smmu->features & ARM_SMMU_FEAT_PRI) {
+		desc = irq_get_msi_desc(smmu->priq.q.irq);
+		if (desc) {
+			get_cached_msi_msg(smmu->priq.q.irq, &msg);
+			arm_smmu_write_msi_msg(desc, &msg);
+		}
+	}
+}
+
 static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
 {
 	int irq, ret;
@@ -3442,7 +3472,7 @@ static void arm_smmu_setup_unique_irqs(struct arm_smmu_device *smmu)
 	}
 }
 
-static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
+static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu, bool resume)
 {
 	int ret, irq;
 	u32 irqen_flags = IRQ_CTRL_EVTQ_IRQEN | IRQ_CTRL_GERROR_IRQEN;
@@ -3456,7 +3486,7 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
 	}
 
 	irq = smmu->combined_irq;
-	if (irq) {
+	if (irq && !resume) {
 		/*
 		 * Cavium ThunderX2 implementation doesn't support unique irq
 		 * lines. Use a single irq line for all the SMMUv3 interrupts.
@@ -3468,8 +3498,12 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
 					"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);
+	} else {
+		if (resume)
+			arm_smmu_resume_unique_irqs(smmu);
+		else
+			arm_smmu_setup_unique_irqs(smmu);
+	}
 
 	if (smmu->features & ARM_SMMU_FEAT_PRI)
 		irqen_flags |= IRQ_CTRL_PRIQ_IRQEN;
@@ -3494,7 +3528,7 @@ static int arm_smmu_device_disable(struct arm_smmu_device *smmu)
 	return ret;
 }
 
-static int arm_smmu_device_reset(struct arm_smmu_device *smmu)
+static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool resume)
 {
 	int ret;
 	u32 reg, enables;
@@ -3602,7 +3636,7 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu)
 		}
 	}
 
-	ret = arm_smmu_setup_irqs(smmu);
+	ret = arm_smmu_setup_irqs(smmu, resume);
 	if (ret) {
 		dev_err(smmu->dev, "failed to setup irqs\n");
 		return ret;
@@ -4086,7 +4120,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	arm_smmu_rmr_install_bypass_ste(smmu);
 
 	/* Reset the device */
-	ret = arm_smmu_device_reset(smmu);
+	ret = arm_smmu_device_reset(smmu, false);
 	if (ret)
 		return ret;
 
@@ -4124,12 +4158,34 @@ static void arm_smmu_device_shutdown(struct platform_device *pdev)
 	arm_smmu_device_disable(smmu);
 }
 
+static int __maybe_unused arm_smmu_suspend(struct device *dev)
+{
+	struct arm_smmu_device *smmu = dev_get_drvdata(dev);
+
+	arm_smmu_device_disable(smmu);
+
+	return 0;
+}
+
+static int __maybe_unused arm_smmu_resume(struct device *dev)
+{
+	struct arm_smmu_device *smmu = dev_get_drvdata(dev);
+
+	arm_smmu_device_reset(smmu, true);
+
+	return 0;
+}
+
 static const struct of_device_id arm_smmu_of_match[] = {
 	{ .compatible = "arm,smmu-v3", },
 	{ },
 };
 MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
 
+static const struct dev_pm_ops arm_smmu_pm_ops = {
+	SET_SYSTEM_SLEEP_PM_OPS(arm_smmu_suspend, arm_smmu_resume)
+};
+
 static void arm_smmu_driver_unregister(struct platform_driver *drv)
 {
 	arm_smmu_sva_notifier_synchronize();
@@ -4141,6 +4197,7 @@ static struct platform_driver arm_smmu_driver = {
 		.name			= "arm-smmu-v3",
 		.of_match_table		= arm_smmu_of_match,
 		.suppress_bind_attrs	= true,
+		.pm			= &arm_smmu_pm_ops,
 	},
 	.probe	= arm_smmu_device_probe,
 	.remove_new = arm_smmu_device_remove,

-- 
2.37.1