Messages in this thread Patch in this message |  | | From | Lu Baolu <> | Subject | [PATCH RFC v3 04/12] iommu/sva: Basic data structures for SVA | Date | Sun, 10 Apr 2022 18:24:35 +0800 |
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Use below data structures for SVA implementation in the IOMMU core:
- struct iommu_sva_ioas Represent the I/O address space shared with an application CPU address space. This structure has a 1:1 relationship with an mm_struct. It graps a "mm->mm_count" refcount during creation and drop it on release.
- struct iommu_domain (IOMMU_DOMAIN_SVA type) Represent a hardware pagetable that the IOMMU hardware could use for SVA translation. Multiple iommu domains could be bound with an SVA ioas and each graps a refcount from ioas in order to make sure ioas could only be freed after all domains have been unbound.
- struct iommu_sva Represent a bond relationship between an SVA ioas and an iommu domain. If a bond already exists, it's reused and a reference is taken.
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> --- include/linux/iommu.h | 14 +++++++++++++- drivers/iommu/iommu-sva-lib.h | 1 + drivers/iommu/iommu-sva-lib.c | 18 ++++++++++++++++++ 3 files changed, 32 insertions(+), 1 deletion(-)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h index fe7d9ee2bc2b..14c3b2197b35 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -42,6 +42,7 @@ struct notifier_block; struct iommu_sva; struct iommu_fault_event; struct iommu_dma_cookie; +struct iommu_sva_ioas; /* iommu fault flags */ #define IOMMU_FAULT_READ 0x0 @@ -64,6 +65,9 @@ struct iommu_domain_geometry { #define __IOMMU_DOMAIN_PT (1U << 2) /* Domain is identity mapped */ #define __IOMMU_DOMAIN_DMA_FQ (1U << 3) /* DMA-API uses flush queue */ +#define __IOMMU_DOMAIN_SHARED (1U << 4) /* Page table shared from CPU */ +#define __IOMMU_DOMAIN_HOST_VA (1U << 5) /* Host CPU virtual address */ + /* * This are the possible domain-types * @@ -86,6 +90,8 @@ struct iommu_domain_geometry { #define IOMMU_DOMAIN_DMA_FQ (__IOMMU_DOMAIN_PAGING | \ __IOMMU_DOMAIN_DMA_API | \ __IOMMU_DOMAIN_DMA_FQ) +#define IOMMU_DOMAIN_SVA (__IOMMU_DOMAIN_SHARED | \ + __IOMMU_DOMAIN_HOST_VA) struct iommu_domain { unsigned type; @@ -95,6 +101,7 @@ struct iommu_domain { void *handler_token; struct iommu_domain_geometry geometry; struct iommu_dma_cookie *iova_cookie; + struct iommu_sva_ioas *sva_ioas; }; static inline bool iommu_is_dma_domain(struct iommu_domain *domain) @@ -622,7 +629,12 @@ struct iommu_fwspec { * struct iommu_sva - handle to a device-mm bond */ struct iommu_sva { - struct device *dev; + struct device *dev; + struct iommu_sva_ioas *sva_ioas; + struct iommu_domain *domain; + /* Link to sva ioas's bonds list */ + struct list_head node; + refcount_t users; }; int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode, diff --git a/drivers/iommu/iommu-sva-lib.h b/drivers/iommu/iommu-sva-lib.h index 8909ea1094e3..9c5e108e2c8a 100644 --- a/drivers/iommu/iommu-sva-lib.h +++ b/drivers/iommu/iommu-sva-lib.h @@ -10,6 +10,7 @@ int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max); struct mm_struct *iommu_sva_find(ioasid_t pasid); +struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain); /* I/O Page fault */ struct device; diff --git a/drivers/iommu/iommu-sva-lib.c b/drivers/iommu/iommu-sva-lib.c index 106506143896..d524a402be3b 100644 --- a/drivers/iommu/iommu-sva-lib.c +++ b/drivers/iommu/iommu-sva-lib.c @@ -3,6 +3,8 @@ * Helpers for IOMMU drivers implementing SVA */ #include <linux/mutex.h> +#include <linux/iommu.h> +#include <linux/slab.h> #include <linux/sched/mm.h> #include "iommu-sva-lib.h" @@ -10,6 +12,22 @@ static DEFINE_MUTEX(iommu_sva_lock); static DECLARE_IOASID_SET(iommu_sva_pasid); +struct iommu_sva_ioas { + struct mm_struct *mm; + ioasid_t pasid; + + /* Counter of domains attached to this ioas. */ + refcount_t users; + + /* All bindings are linked here. */ + struct list_head bonds; +}; + +struct mm_struct *iommu_sva_domain_mm(struct iommu_domain *domain) +{ + return domain->sva_ioas->mm; +} + /** * iommu_sva_alloc_pasid - Allocate a PASID for the mm * @mm: the mm -- 2.25.1
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