driver/iommu/smmu-v3: Support smmu suspend/resume.

ascend inclusion
category: feature
bugzilla: 14369
CVE: NA
-------------------

Smmu need to reconfiguration when the device resumed. So
must support smmu suspend/resume.
Signed-off-by: NJiankang Chen <chenjiankang1@huawei.com>
Signed-off-by: NFang Lijun <fanglijun3@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Reviewed-by: NHanjun Guo <guohanjun@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/iommu/arm-smmu-v3.c

@@ -647,6 +647,10 @@ struct arm_smmu_device {
 	struct mutex			streams_mutex;
 
 	struct iopf_queue		*iopf_queue;
+
+#define ARM_SUMMU_STATE_BYPASS		(1 << 0)
+#define ARM_SUMMU_STATE_SUSPEND		(1 << 1)
+	unsigned int			state;
 };
 
 struct arm_smmu_stream {
@@ -3374,6 +3378,9 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
 		return ret;
 	}
 
+	if (smmu->state & ARM_SUMMU_STATE_SUSPEND)
+		goto irq_requested;
+
 	irq = smmu->combined_irq;
 	if (irq) {
 		/*
@@ -3393,6 +3400,7 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu)
 	if (smmu->features & ARM_SMMU_FEAT_PRI)
 		irqen_flags |= IRQ_CTRL_PRIQ_IRQEN;
 
+irq_requested:
 	/* Enable interrupt generation on the SMMU */
 	ret = arm_smmu_write_reg_sync(smmu, irqen_flags,
 				      ARM_SMMU_IRQ_CTRL, ARM_SMMU_IRQ_CTRLACK);
@@ -3939,6 +3947,9 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
 	/* Set bypass mode according to firmware probing result */
 	bypass = !!ret;
 
+	if (bypass)
+		smmu->state = smmu->state | ARM_SUMMU_STATE_BYPASS;
+
 	/* Base address */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (resource_size(res) + 1 < arm_smmu_resource_size(smmu)) {
@@ -4054,10 +4065,47 @@ static const struct of_device_id arm_smmu_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, arm_smmu_of_match);
 
+#ifdef CONFIG_PM_SLEEP
+
+static int arm_smmu_suspend(struct device *dev)
+{
+	struct arm_smmu_device *smmu = dev_get_drvdata(dev);
+
+	dev_info(smmu->dev, "smmu device is suspend\n");
+	smmu->state = smmu->state | ARM_SUMMU_STATE_SUSPEND;
+
+	return 0;
+}
+
+static int arm_smmu_resume(struct device *dev)
+{
+	struct arm_smmu_device *smmu = dev_get_drvdata(dev);
+
+	dev_info(smmu->dev, "smmu device is resumed\n");
+	arm_smmu_device_reset(smmu, smmu->state & ARM_SUMMU_STATE_BYPASS);
+	smmu->state = smmu->state & ~ARM_SUMMU_STATE_SUSPEND;
+
+	return 0;
+}
+
+static const struct dev_pm_ops arm_smmu_pm_ops = {
+	.suspend = arm_smmu_suspend,
+	.resume = arm_smmu_resume,
+};
+
+#define ARM_SMMU_PM_OPS			(&arm_smmu_pm_ops)
+
+#else
+
+#define ARM_SMMU_PM_OPS			NULL
+
+#endif
+
 static struct platform_driver arm_smmu_driver = {
 	.driver	= {
 		.name		= "arm-smmu-v3",
 		.of_match_table	= of_match_ptr(arm_smmu_of_match),
+		.pm		= ARM_SMMU_PM_OPS,
 	},
 	.probe	= arm_smmu_device_probe,
 	.remove	= arm_smmu_device_remove,