Messages in this thread Patch in this message |  | | From | Lu Baolu <> | Subject | [PATCH RFC 03/11] iommu: Add attach/detach_dev_pasid domain ops | Date | Sun, 20 Mar 2022 14:40:22 +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 - kernel DMA with PASID - hardware-assist mediated device
This adds a pair of common domain ops for this purpose and implements a couple of wrapper helpers for in-kernel usage.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> --- include/linux/iommu.h | 22 ++++++++++++++++++++++ drivers/iommu/iommu.c | 41 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 63 insertions(+)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 3e179b853380..e51845b9a146 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -268,6 +268,8 @@ 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. @@ -285,6 +287,10 @@ 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); @@ -678,6 +684,11 @@ 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 {}; @@ -1046,6 +1057,17 @@ 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 0c42ece25854..78c71ee15f36 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3167,3 +3167,44 @@ 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; + + if (!domain->ops->attach_dev_pasid) + return -EINVAL; + + group = iommu_group_get(dev); + if (!group) + return -ENODEV; + + mutex_lock(&group->mutex); + if (iommu_group_device_count(group) != 1) + goto out_unlock; + + ret = domain->ops->attach_dev_pasid(domain, dev, 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); + mutex_unlock(&group->mutex); + iommu_group_put(group); +} -- 2.25.1
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