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Subject[PATCH -next v2] iommu/arm-smmu-v3: Add suspend and resume support
Date
Add suspend and resume support for arm-smmu-v3 by low-power mode.

When the smmu is suspended, it is powered off and the registers are
cleared. So saves the msi_msg context during msi interrupt initialization
of smmu. When resume happens it calls arm_smmu_device_reset() to restore
the registers.

Signed-off-by: Bixuan Cui <cuibixuan@huawei.com>
Reviewed-by: Wei Yongjun <weiyongjun1@huawei.com>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Ding Tianhong <dingtianhong@huawei.com>
Reviewed-by: Hanjun Guo <guohanjun@huawei.com>
---
Changes in v2:
* Using get_cached_msi_msg() instead of the descriptor to resume msi_msg
in arm_smmu_resume_msis();

* Move arm_smmu_resume_msis() from arm_smmu_setup_unique_irqs() into
arm_smmu_setup_irqs() and rename it to arm_smmu_resume_unique_irqs();

Call arm_smmu_setup_unique_irqs() to configure the IRQ during probe and
call arm_smmu_resume_unique_irqs() in resume mode to restore the IRQ
registers to make the code more reasonable.

* Call arm_smmu_device_disable() to disable smmu and clear CR0_SMMUEN on
suspend. Then the warning about CR0_SMMUEN being enabled can be cleared
on resume.

* Using SET_SYSTEM_SLEEP_PM_OPS();

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 69 ++++++++++++++++++---
1 file changed, 62 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 235f9bdaeaf2..66f35d5c7a70 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -40,6 +40,7 @@ MODULE_PARM_DESC(disable_bypass,

static bool disable_msipolling;
module_param(disable_msipolling, bool, 0444);
+static bool bypass;
MODULE_PARM_DESC(disable_msipolling,
"Disable MSI-based polling for CMD_SYNC completion.");

@@ -3129,11 +3130,38 @@ static void arm_smmu_write_msi_msg(struct msi_desc *desc, struct msi_msg *msg)
doorbell = (((u64)msg->address_hi) << 32) | msg->address_lo;
doorbell &= MSI_CFG0_ADDR_MASK;

+ /* Saves the msg context for resume if desc->msg is empty */
+ if (desc->msg.address_lo == 0x0 && desc->msg.address_hi == 0x0) {
+ desc->msg.address_lo = msg->address_lo;
+ desc->msg.address_hi = msg->address_hi;
+ desc->msg.data = msg->data;
+ }
+
writeq_relaxed(doorbell, smmu->base + cfg[0]);
writel_relaxed(msg->data, smmu->base + cfg[1]);
writel_relaxed(ARM_SMMU_MEMATTR_DEVICE_nGnRE, smmu->base + cfg[2]);
}

+static void arm_smmu_resume_unique_irqs(struct arm_smmu_device *smmu)
+{
+ struct msi_desc *desc;
+ struct msi_msg msg;
+
+ desc = irq_get_msi_desc(smmu->evtq.q.irq);
+ get_cached_msi_msg(smmu->evtq.q.irq, &msg);
+ arm_smmu_write_msi_msg(desc, &msg);
+
+ desc = irq_get_msi_desc(smmu->gerr_irq);
+ 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);
+ get_cached_msi_msg(smmu->priq.q.irq, &msg);
+ arm_smmu_write_msi_msg(desc, &msg);
+ }
+}
+
static void arm_smmu_setup_msis(struct arm_smmu_device *smmu)
{
struct msi_desc *desc;
@@ -3230,7 +3258,7 @@ 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_mode)
{
int ret, irq;
u32 irqen_flags = IRQ_CTRL_EVTQ_IRQEN | IRQ_CTRL_GERROR_IRQEN;
@@ -3256,8 +3284,12 @@ 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_mode)
+ arm_smmu_setup_unique_irqs(smmu);
+ else
+ arm_smmu_resume_unique_irqs(smmu);
+ }

if (smmu->features & ARM_SMMU_FEAT_PRI)
irqen_flags |= IRQ_CTRL_PRIQ_IRQEN;
@@ -3282,7 +3314,7 @@ static int arm_smmu_device_disable(struct arm_smmu_device *smmu)
return ret;
}

-static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
+static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool resume_mode)
{
int ret;
u32 reg, enables;
@@ -3392,7 +3424,7 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass)
}
}

- ret = arm_smmu_setup_irqs(smmu);
+ ret = arm_smmu_setup_irqs(smmu, resume_mode);
if (ret) {
dev_err(smmu->dev, "failed to setup irqs\n");
return ret;
@@ -3749,6 +3781,25 @@ static void __iomem *arm_smmu_ioremap(struct device *dev, resource_size_t start,
return devm_ioremap_resource(dev, &res);
}

+static int __maybe_unused arm_smmu_suspend(struct device *dev)
+{
+ struct arm_smmu_device *smmu = dev_get_drvdata(dev);
+
+ /* disable smmu to clear CR0 */
+ 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 int arm_smmu_device_probe(struct platform_device *pdev)
{
int irq, ret;
@@ -3756,7 +3807,6 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
resource_size_t ioaddr;
struct arm_smmu_device *smmu;
struct device *dev = &pdev->dev;
- bool bypass;

smmu = devm_kzalloc(dev, sizeof(*smmu), GFP_KERNEL);
if (!smmu)
@@ -3831,7 +3881,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, smmu);

/* Reset the device */
- ret = arm_smmu_device_reset(smmu, bypass);
+ ret = arm_smmu_device_reset(smmu, false);
if (ret)
return ret;

@@ -3884,6 +3934,10 @@ static const struct of_device_id arm_smmu_of_match[] = {
};
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();
@@ -3895,6 +3949,7 @@ 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 = arm_smmu_device_remove,
--
2.17.1
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