Messages in this thread Patch in this message | | | From | Lu Baolu <> | Subject | [PATCH RFC v2 04/11] iommu: Add attach/detach_dev_pasid domain ops | Date | Tue, 29 Mar 2022 13:37:53 +0800 |
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Attaching an IOMMU domain to a PASID of a device is a generic operation for modern IOMMU drivers which support PASID-granular DMA address translation. Currently visible usage scenarios include (but not limited):
- SVA (Shared Virtual Address) - kernel DMA with PASID - hardware-assist mediated device
This adds a pair of common domain ops for this purpose and adds some common helpers to attach/detach a domain to/from a {device, PASID} and get/put the domain attached to {device, PASID}.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> --- include/linux/iommu.h | 36 ++++++++++++++++++ drivers/iommu/iommu.c | 88 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 124 insertions(+)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 29c4c2edd706..a46285488a57 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -269,6 +269,8 @@ struct iommu_ops { * struct iommu_domain_ops - domain specific operations * @attach_dev: attach an iommu domain to a device * @detach_dev: detach an iommu domain from a device + * @attach_dev_pasid: attach an iommu domain to a pasid of device + * @detach_dev_pasid: detach an iommu domain from a pasid of device * @map: map a physically contiguous memory region to an iommu domain * @map_pages: map a physically contiguous set of pages of the same size to * an iommu domain. @@ -286,6 +288,10 @@ struct iommu_ops { struct iommu_domain_ops { int (*attach_dev)(struct iommu_domain *domain, struct device *dev); void (*detach_dev)(struct iommu_domain *domain, struct device *dev); + int (*attach_dev_pasid)(struct iommu_domain *domain, + struct device *dev, ioasid_t id); + void (*detach_dev_pasid)(struct iommu_domain *domain, + struct device *dev, ioasid_t id); int (*map)(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot, gfp_t gfp); @@ -679,6 +685,14 @@ int iommu_group_claim_dma_owner(struct iommu_group *group, void *owner); void iommu_group_release_dma_owner(struct iommu_group *group); bool iommu_group_dma_owner_claimed(struct iommu_group *group); +int iommu_attach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid); +void iommu_detach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid); +struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid); +void iommu_put_domain_for_dev_pasid(struct iommu_domain *domain); + #else /* CONFIG_IOMMU_API */ struct iommu_ops {}; @@ -1047,6 +1061,28 @@ static inline bool iommu_group_dma_owner_claimed(struct iommu_group *group) { return false; } + +static inline int iommu_attach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid) +{ + return -ENODEV; +} + +static inline void iommu_detach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid) +{ +} + +static inline struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid) +{ + return NULL; +} + +static inline void +iommu_put_domain_for_dev_pasid(struct iommu_domain *domain) +{ +} #endif /* CONFIG_IOMMU_API */ /** diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 9fb8a5b4491e..8163ad7f6902 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -27,6 +27,8 @@ #include <linux/cc_platform.h> #include <trace/events/iommu.h> +#include "iommu-sva-lib.h" + static struct kset *iommu_group_kset; static DEFINE_IDA(iommu_group_ida); @@ -38,6 +40,7 @@ struct iommu_group { struct kobject kobj; struct kobject *devices_kobj; struct list_head devices; + struct xarray pasid_array; struct mutex mutex; void *iommu_data; void (*iommu_data_release)(void *iommu_data); @@ -631,6 +634,7 @@ struct iommu_group *iommu_group_alloc(void) mutex_init(&group->mutex); INIT_LIST_HEAD(&group->devices); INIT_LIST_HEAD(&group->entry); + xa_init(&group->pasid_array); ret = ida_simple_get(&iommu_group_ida, 0, 0, GFP_KERNEL); if (ret < 0) { @@ -3173,3 +3177,87 @@ bool iommu_group_dma_owner_claimed(struct iommu_group *group) return user; } EXPORT_SYMBOL_GPL(iommu_group_dma_owner_claimed); + +int iommu_attach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid) +{ + struct iommu_group *group; + int ret = -EINVAL; + void *curr; + + if (!domain->ops->attach_dev_pasid) + return -EINVAL; + + group = iommu_group_get(dev); + if (!group) + return -ENODEV; + + mutex_lock(&group->mutex); + /* + * To keep things simple, we currently don't support IOMMU groups + * with more than one device. Existing SVA-capable systems are not + * affected by the problems that required IOMMU groups (lack of ACS + * isolation, device ID aliasing and other hardware issues). + */ + if (!iommu_group_singleton_lockdown(group)) + goto out_unlock; + + xa_lock(&group->pasid_array); + curr = __xa_cmpxchg(&group->pasid_array, pasid, NULL, + domain, GFP_KERNEL); + xa_unlock(&group->pasid_array); + if (curr) + goto out_unlock; + + ret = domain->ops->attach_dev_pasid(domain, dev, pasid); + if (ret) + xa_erase(&group->pasid_array, pasid); + +out_unlock: + mutex_unlock(&group->mutex); + iommu_group_put(group); + + return ret; +} + +void iommu_detach_device_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid) +{ + struct iommu_group *group; + + group = iommu_group_get(dev); + if (WARN_ON(!group)) + return; + + mutex_lock(&group->mutex); + domain->ops->detach_dev_pasid(domain, dev, pasid); + xa_erase(&group->pasid_array, pasid); + mutex_unlock(&group->mutex); + iommu_group_put(group); +} + +struct iommu_domain * +iommu_get_domain_for_dev_pasid(struct device *dev, ioasid_t pasid) +{ + struct iommu_domain *domain; + struct iommu_group *group; + + group = iommu_group_get(dev); + if (!group) + return NULL; + + mutex_lock(&group->mutex); + domain = xa_load(&group->pasid_array, pasid); + if (domain && domain->type == IOMMU_DOMAIN_SVA) + iommu_sva_domain_get_user(domain); + mutex_unlock(&group->mutex); + iommu_group_put(group); + + return domain; +} + +void iommu_put_domain_for_dev_pasid(struct iommu_domain *domain) +{ + if (domain->type == IOMMU_DOMAIN_SVA) + iommu_sva_domain_put_user(domain); +} -- 2.25.1
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