Messages in this thread Patch in this message |  | | From | Lu Baolu <> | Subject | [PATCH RFC v3 03/12] iommu: Add attach/detach_dev_pasid domain ops | Date | Sun, 10 Apr 2022 18:24:34 +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 helpers to attach/detach a domain to/from a {device, PASID}.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> --- include/linux/iommu.h | 21 +++++++++++++++++++ drivers/iommu/iommu.c | 48 +++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 69 insertions(+)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 36f43af0af53..fe7d9ee2bc2b 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -262,6 +262,8 @@ 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. @@ -279,6 +281,10 @@ 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 pasid); + void (*detach_dev_pasid)(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid); int (*map)(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t size, int prot, gfp_t gfp); @@ -672,6 +678,10 @@ 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); #else /* CONFIG_IOMMU_API */ struct iommu_ops {}; @@ -1040,6 +1050,17 @@ 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) +{ +} #endif /* CONFIG_IOMMU_API */ /** diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index 56ffbf5fdc18..63f880dd0c80 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -38,6 +38,7 @@ 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); @@ -642,6 +643,7 @@ 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) { @@ -3214,3 +3216,49 @@ 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); + if (!group->immutable_singleton) + goto out_unlock; + + curr = xa_cmpxchg(&group->pasid_array, pasid, NULL, domain, GFP_KERNEL); + 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 = iommu_group_get(dev); + + 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); +} -- 2.25.1
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