答复: [PATCH v3 2/2] iommu/vt-d:Add support for probing ACPI device in RMRR

[FelixCui-oc <FelixCui-oc@zhaoxin.com>]

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hi  baolu ,

                   These ACPI devices can be retrieved from the kernel and there is no bound device driver .


Best regards

Felixcui-oc

________________________________
发件人: Lu Baolu <baolu.lu@linux.intel.com>
发送时间: 2020年9月1日 14:12:34
收件人: FelixCui-oc; Joerg Roedel; iommu@lists.linux-foundation.org; linux-kernel@vger.kernel.org; David Woodhouse; Dan Carpenter; kbuild@lists.01.org
抄送: baolu.lu@linux.intel.com; CobeChen-oc; RaymondPang-oc; Tony W Wang-oc
主题: Re: [PATCH v3 2/2] iommu/vt-d:Add support for probing ACPI device in RMRR

Hi Felix,

On 8/27/20 6:02 PM, FelixCuioc wrote:
> After acpi device in RMRR is detected,it is necessary
> to establish a mapping for these devices.
> In acpi_device_create_direct_mappings(),create a mapping
> for the acpi device in RMRR.
> Add a helper to achieve the acpi namespace device can
> access the RMRR region.

Are those ACPI devices visible to kernel? If so, any device driver bound
for it?

Best regards,
baolu

>
> Signed-off-by: FelixCuioc <FelixCui-oc@zhaoxin.com>
> ---
>   drivers/iommu/intel/iommu.c | 29 +++++++++++++++++++++++++++++
>   drivers/iommu/iommu.c       |  6 ++++++
>   include/linux/iommu.h       |  3 +++
>   3 files changed, 38 insertions(+)
>
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index 208a91605288..51d7a5b18f41 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -4799,6 +4799,21 @@ static int __init platform_optin_force_iommu(void)
>        return 1;
>   }
>
> +static int acpi_device_create_direct_mappings(struct device *pn_dev, struct device *acpi_device)
> +{
> +     struct iommu_group *group;
> +
> +     acpi_device->bus->iommu_ops = &intel_iommu_ops;
> +     group = iommu_group_get(pn_dev);
> +     if (!group) {
> +             pr_warn("ACPI name space devices create direct mappings wrong!\n");
> +             return -EINVAL;
> +     }
> +     __acpi_device_create_direct_mappings(group, acpi_device);
> +
> +     return 0;
> +}
> +
>   static int __init probe_acpi_namespace_devices(void)
>   {
>        struct dmar_drhd_unit *drhd;
> @@ -4813,6 +4828,7 @@ static int __init probe_acpi_namespace_devices(void)
>                        struct acpi_device_physical_node *pn;
>                        struct iommu_group *group;
>                        struct acpi_device *adev;
> +                     struct device *pn_dev = NULL;
>
>                        if (dev->bus != &acpi_bus_type)
>                                continue;
> @@ -4823,6 +4839,7 @@ static int __init probe_acpi_namespace_devices(void)
>                                            &adev->physical_node_list, node) {
>                                group = iommu_group_get(pn->dev);
>                                if (group) {
> +                                     pn_dev = pn->dev;
>                                        iommu_group_put(group);
>                                        continue;
>                                }
> @@ -4831,7 +4848,19 @@ static int __init probe_acpi_namespace_devices(void)
>                                ret = iommu_probe_device(pn->dev);
>                                if (ret)
>                                        break;
> +                             pn_dev = pn->dev;
> +                     }
> +                     if (!pn_dev) {
> +                             dev->bus->iommu_ops = &intel_iommu_ops;
> +                             ret = iommu_probe_device(dev);
> +                             if (ret) {
> +                                     pr_err("acpi_device probe fail! ret:%d\n", ret);
> +                                     goto unlock;
> +                             }
> +                             goto unlock;
>                        }
> +                     ret = acpi_device_create_direct_mappings(pn_dev, dev);
> +unlock:
>                        mutex_unlock(&adev->physical_node_lock);
>
>                        if (ret)
> diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
> index 609bd25bf154..4f714a2d5ef7 100644
> --- a/drivers/iommu/iommu.c
> +++ b/drivers/iommu/iommu.c
> @@ -779,6 +779,12 @@ static bool iommu_is_attach_deferred(struct iommu_domain *domain,
>        return false;
>   }
>
> +void  __acpi_device_create_direct_mappings(struct iommu_group *group, struct device *acpi_device)
> +{
> +     iommu_create_device_direct_mappings(group, acpi_device);
> +}
> +EXPORT_SYMBOL_GPL(__acpi_device_create_direct_mappings);
> +
>   /**
>    * iommu_group_add_device - add a device to an iommu group
>    * @group: the group into which to add the device (reference should be held)
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index fee209efb756..9be134775886 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -514,6 +514,9 @@ extern void iommu_domain_window_disable(struct iommu_domain *domain, u32 wnd_nr)
>   extern int report_iommu_fault(struct iommu_domain *domain, struct device *dev,
>                              unsigned long iova, int flags);
>
> +extern void __acpi_device_create_direct_mappings(struct iommu_group *group,
> +                                             struct device *acpi_device);
> +
>   static inline void iommu_flush_tlb_all(struct iommu_domain *domain)
>   {
>        if (domain->ops->flush_iotlb_all)
>

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