Messages in this thread | | | Date | Sat, 1 Apr 2023 21:16:39 +0800 | Subject | Re: [PATCH v3 3/7] iommu/sva: Support allocation of global PASIDs outside SVA | From | Baolu Lu <> |
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On 2023/4/1 7:11, Jacob Pan wrote: > Devices that use Intel ENQCMD to submit work must use global PASIDs in > that the PASID are stored in a per CPU MSR. When such device need to > submit work for in-kernel DMA with PASID, it must allocate PASIDs from > the same global number space to avoid conflict. > > This patch moves global PASID allocation APIs from SVA to IOMMU APIs. > It is expected that device drivers will use the allocated PASIDs to attach > to appropriate IOMMU domains for use. > > Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com> > --- > drivers/iommu/iommu-sva.c | 10 ++++------ > drivers/iommu/iommu.c | 33 +++++++++++++++++++++++++++++++++ > include/linux/iommu.h | 10 ++++++++++ > 3 files changed, 47 insertions(+), 6 deletions(-) > > diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c > index c434b95dc8eb..222544587582 100644 > --- a/drivers/iommu/iommu-sva.c > +++ b/drivers/iommu/iommu-sva.c > @@ -9,15 +9,13 @@ > #include "iommu-sva.h" > > static DEFINE_MUTEX(iommu_sva_lock); > -static DEFINE_IDA(iommu_global_pasid_ida); > > /* Allocate a PASID for the mm within range (inclusive) */ > static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max) > { > int ret = 0; > > - if (!pasid_valid(min) || !pasid_valid(max) || > - min == 0 || max < min) > + if (!pasid_valid(min) || !pasid_valid(max) || max < min) > return -EINVAL; > > mutex_lock(&iommu_sva_lock); > @@ -28,8 +26,8 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t ma > goto out; > } > > - ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL); > - if (ret < min) > + ret = iommu_alloc_global_pasid(min, max); > + if (!pasid_valid(ret)) > goto out; > mm->pasid = ret; > ret = 0; > @@ -211,5 +209,5 @@ void mm_pasid_drop(struct mm_struct *mm) > if (likely(!pasid_valid(mm->pasid))) > return; > > - ida_free(&iommu_global_pasid_ida, mm->pasid); > + iommu_free_global_pasid(mm->pasid); > } > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index 10db680acaed..5a8ffdc3063d 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -38,6 +38,7 @@ > > static struct kset *iommu_group_kset; > static DEFINE_IDA(iommu_group_ida); > +static DEFINE_IDA(iommu_global_pasid_ida); > > static unsigned int iommu_def_domain_type __read_mostly; > static bool iommu_dma_strict __read_mostly = IS_ENABLED(CONFIG_IOMMU_DEFAULT_DMA_STRICT); > @@ -3450,3 +3451,35 @@ struct iommu_domain *iommu_sva_domain_alloc(struct device *dev, > > return domain; > } > + > +/** > + * @brief > + * Reserve a PASID from the SVA global number space. > + * > + * @param min starting range, inclusive > + * @param max ending range, inclusive > + * @return The reserved PASID on success or IOMMU_PASID_INVALID on failure. > + */
Nit: the comments here also need to be changed accordingly.
Best regards, baolu
> +ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max) > +{ > + int ret; > + > + if (!pasid_valid(min) || !pasid_valid(max) || max < min) > + return IOMMU_PASID_INVALID; > + > + ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL); > + if (ret < 0) > + return IOMMU_PASID_INVALID; > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(iommu_alloc_global_pasid); > + > +void iommu_free_global_pasid(ioasid_t pasid) > +{ > + if (WARN_ON(!pasid_valid(pasid))) > + return; > + > + ida_free(&iommu_global_pasid_ida, pasid); > +} > +EXPORT_SYMBOL_GPL(iommu_free_global_pasid); > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index 54f535ff9868..f70478a11a5f 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -1187,6 +1187,9 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, > struct mm_struct *mm); > void iommu_sva_unbind_device(struct iommu_sva *handle); > u32 iommu_sva_get_pasid(struct iommu_sva *handle); > +ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max); > +void iommu_free_global_pasid(ioasid_t pasid); > + > #else > static inline struct iommu_sva * > iommu_sva_bind_device(struct device *dev, struct mm_struct *mm) > @@ -1202,6 +1205,13 @@ static inline u32 iommu_sva_get_pasid(struct iommu_sva *handle) > { > return IOMMU_PASID_INVALID; > } > + > +static inline ioasid_t iommu_alloc_global_pasid(ioasid_t min, ioasid_t max) > +{ > + return IOMMU_PASID_INVALID; > +} > + > +static inline void iommu_free_global_pasid(ioasid_t pasid) {} > static inline void mm_pasid_init(struct mm_struct *mm) {} > static inline void mm_pasid_drop(struct mm_struct *mm) {} > #endif /* CONFIG_IOMMU_SVA */
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