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BACKPORT: FROMLIST: iommu/arm-smmu-v3-kvm: Enable runtime PM

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Enable runtime PM for the KVM SMMUv3 driver. The PM link to DMA masters
dictates when the SMMU should be powered on.

Link: https://lore.kernel.org/all/20241212180423.1578358-55-smostafa@google.com/

Bug: 357781595
Bug: 384432312

Change-Id: I54cc1ef0970f87ee6a8d18a6b79872c67b624837
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
This commit is contained in:
Mostafa Saleh
2024-12-12 18:04:18 +00:00
parent 2717852bd5
commit 89d72fc11f
1 changed files with 66 additions and 0 deletions
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drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-kvm.c
+66
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@@ -11,6 +11,7 @@
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <kvm/arm_smmu_v3.h>
@@ -127,6 +128,12 @@ static struct iommu_device *kvm_arm_smmu_probe_device(struct device *dev)
master->ssid_bits = min(smmu->ssid_bits, master->ssid_bits);
xa_init(&master->domains);
dev_iommu_priv_set(dev, master);
if (!device_link_add(dev, smmu->dev,
DL_FLAG_PM_RUNTIME |
DL_FLAG_AUTOREMOVE_SUPPLIER)) {
kfree(master);
return ERR_PTR(-ENOLINK);
}
return &smmu->iommu;
}
@@ -818,6 +825,14 @@ static int kvm_arm_smmu_probe(struct platform_device *pdev)
hyp_smmu->iommu.power_domain = host_smmu->power_domain;
kvm_arm_smmu_cur++;
pm_runtime_set_active(dev);
pm_runtime_enable(dev);
/*
* Take a reference to keep the SMMU powered on while the hypervisor
* initializes it.
*/
pm_runtime_resume_and_get(dev);
return arm_smmu_register_iommu(smmu, &kvm_arm_smmu_ops, ioaddr);
}
@@ -826,6 +841,8 @@ static void kvm_arm_smmu_remove(struct platform_device *pdev)
struct arm_smmu_device *smmu = platform_get_drvdata(pdev);
struct host_arm_smmu_device *host_smmu = smmu_to_host(smmu);
pm_runtime_disable(&pdev->dev);
pm_runtime_set_suspended(&pdev->dev);
/*
* There was an error during hypervisor setup. The hyp driver may
* have already enabled the device, so disable it.
@@ -834,6 +851,30 @@ static void kvm_arm_smmu_remove(struct platform_device *pdev)
arm_smmu_update_gbpa(smmu, host_smmu->boot_gbpa, GBPA_ABORT);
}
static int kvm_arm_smmu_suspend(struct device *dev)
{
struct arm_smmu_device *smmu = dev_get_drvdata(dev);
struct host_arm_smmu_device *host_smmu = smmu_to_host(smmu);
if (host_smmu->power_domain.type == KVM_POWER_DOMAIN_HOST_HVC)
return kvm_call_hyp_nvhe(__pkvm_host_hvc_pd, host_smmu->id, 0);
return 0;
}
static int kvm_arm_smmu_resume(struct device *dev)
{
struct arm_smmu_device *smmu = dev_get_drvdata(dev);
struct host_arm_smmu_device *host_smmu = smmu_to_host(smmu);
if (host_smmu->power_domain.type == KVM_POWER_DOMAIN_HOST_HVC)
return kvm_call_hyp_nvhe(__pkvm_host_hvc_pd, host_smmu->id, 1);
return 0;
}
static const struct dev_pm_ops kvm_arm_smmu_pm_ops = {
SET_RUNTIME_PM_OPS(kvm_arm_smmu_suspend, kvm_arm_smmu_resume, NULL)
};
static const struct of_device_id arm_smmu_of_match[] = {
{ .compatible = "arm,smmu-v3", },
{ },
@@ -843,6 +884,7 @@ static struct platform_driver kvm_arm_smmu_driver = {
.driver = {
.name = "kvm-arm-smmu-v3",
.of_match_table = arm_smmu_of_match,
.pm = &kvm_arm_smmu_pm_ops,
},
.remove = kvm_arm_smmu_remove,
};
@@ -877,6 +919,12 @@ static void kvm_arm_smmu_array_free(void)
free_pages((unsigned long)kvm_arm_smmu_array, order);
}
static int smmu_put_device(struct device *dev, void *data)
{
pm_runtime_put(dev);
return 0;
}
static int kvm_arm_smmu_v3_init_drv(void)
{
int ret;
@@ -905,6 +953,7 @@ static int kvm_arm_smmu_v3_init_drv(void)
*/
kvm_hyp_arm_smmu_v3_smmus = kvm_arm_smmu_array;
kvm_hyp_arm_smmu_v3_count = kvm_arm_smmu_count;
return 0;
err_free:
@@ -931,4 +980,21 @@ static int kvm_arm_smmu_v3_register(void)
kern_hyp_va(lm_alias(&kvm_nvhe_sym(smmu_ops))));
};
/*
* KVM init hypervisor at device_sync init call,
* so we drop the PM references of the SMMU taken at probe
* at the late initcall where it's guaranteed the hypervisor
* has initialized the SMMUs.
*/
static int kvm_arm_smmu_v3_post_init(void)
{
if (!kvm_arm_smmu_count)
return 0;
WARN_ON(driver_for_each_device(&kvm_arm_smmu_driver.driver, NULL,
NULL, smmu_put_device));
return 0;
}
core_initcall(kvm_arm_smmu_v3_register);
late_initcall(kvm_arm_smmu_v3_post_init);