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 <[email protected]> Reviewed-by: Wei Yongjun <[email protected]> Reviewed-by: Zhen Lei <[email protected]> Reviewed-by: Ding Tianhong <[email protected]> Reviewed-by: Hanjun Guo <[email protected]> --- Changes in v4: * Restore the arm_smmu_suspend() function code to the v2 version(Directly return 0 in it). Changes in v3: * Move the code of save msg context into msi platform (A new patch: "platform-msi: Save the msg context to desc in platform_msi_write_msg()"). * Add bypass member to the struct arm_smmu_device for per-SMMU bypass control(used by resume mode). * Separate interrupt requests and register operations in arm_smmu_device_reset(). The arm_smmu_setup_irqs() is added to request interrupts and is called before arm_smmu_device_reset(). The arm_smmu_device_reset() resets irq registers (can also be called in resume mode). 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 | 94 +++++++++++++++++++-- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 1 + 2 files changed, 88 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 a388e318f86e..af6752a735bb 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -3282,6 +3282,61 @@ static int arm_smmu_setup_irqs(struct arm_smmu_device *smmu) return 0; } +static void arm_smmu_reset_unique_irqs(struct arm_smmu_device *smmu) +{ + struct msi_desc *desc; + struct msi_msg msg; + + 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 int arm_smmu_reset_irqs(struct arm_smmu_device *smmu) +{ + int ret, irq; + u32 irqen_flags = IRQ_CTRL_EVTQ_IRQEN | IRQ_CTRL_GERROR_IRQEN; + + /* Disable IRQs first */ + ret = arm_smmu_write_reg_sync(smmu, 0, ARM_SMMU_IRQ_CTRL, + ARM_SMMU_IRQ_CTRLACK); + if (ret) { + dev_err(smmu->dev, "failed to disable irqs\n"); + return ret; + } + + irq = smmu->combined_irq; + if (!irq) + arm_smmu_reset_unique_irqs(smmu); + + if (smmu->features & ARM_SMMU_FEAT_PRI) + irqen_flags |= IRQ_CTRL_PRIQ_IRQEN; + + /* Enable interrupt generation on the SMMU */ + ret = arm_smmu_write_reg_sync(smmu, irqen_flags, + ARM_SMMU_IRQ_CTRL, ARM_SMMU_IRQ_CTRLACK); + if (ret) + dev_warn(smmu->dev, "failed to reset irqs\n"); + + return 0; +} + static int arm_smmu_device_disable(struct arm_smmu_device *smmu) { int ret; @@ -3293,7 +3348,7 @@ 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) { int ret; u32 reg, enables; @@ -3401,9 +3456,9 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass) } } - ret = arm_smmu_setup_irqs(smmu); + ret = arm_smmu_reset_irqs(smmu); if (ret) { - dev_err(smmu->dev, "failed to setup irqs\n"); + dev_err(smmu->dev, "failed to reset irqs\n"); return ret; } @@ -3411,7 +3466,7 @@ static int arm_smmu_device_reset(struct arm_smmu_device *smmu, bool bypass) enables &= ~(CR0_EVTQEN | CR0_PRIQEN); /* Enable the SMMU interface, or ensure bypass */ - if (!bypass || disable_bypass) { + if (!smmu->bypass || disable_bypass) { enables |= CR0_SMMUEN; } else { ret = arm_smmu_update_gbpa(smmu, 0, GBPA_ABORT); @@ -3758,6 +3813,20 @@ 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) +{ + 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); + + return 0; +} + static int arm_smmu_device_probe(struct platform_device *pdev) { int irq, ret; @@ -3765,7 +3834,6 @@ 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) @@ -3781,7 +3849,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev) } /* Set bypass mode according to firmware probing result */ - bypass = !!ret; + smmu->bypass = !!ret; /* Base address */ res = platform_get_resource(pdev, IORESOURCE_MEM, 0); @@ -3839,8 +3907,15 @@ static int arm_smmu_device_probe(struct platform_device *pdev) /* Record our private device structure */ platform_set_drvdata(pdev, smmu); + /* Setup irqs */ + ret = arm_smmu_setup_irqs(smmu); + if (ret) { + dev_err(smmu->dev, "failed to setup irqs\n"); + return ret; + } + /* Reset the device */ - ret = arm_smmu_device_reset(smmu, bypass); + ret = arm_smmu_device_reset(smmu); if (ret) return ret; @@ -3893,6 +3968,10 @@ 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(); @@ -3904,6 +3983,7 @@ 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, diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h index 4cb136f07914..7777a7445bc2 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -675,6 +675,7 @@ struct arm_smmu_device { struct rb_root streams; struct mutex streams_mutex; + bool bypass; }; struct arm_smmu_stream { -- 2.17.1 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
