Messages in this thread | | | Date | Tue, 8 Aug 2023 12:12:42 -0300 | From | Jason Gunthorpe <> | Subject | Re: [PATCH 4/5] iommu: Support mm PASID 1:n with sva domains |
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On Tue, Aug 08, 2023 at 03:49:43PM +0800, Tina Zhang wrote: > Each mm bound to devices gets a PASID and corresponding sva domains > allocated in iommu_sva_bind_device(), which are referenced by iommu_mm > field of the mm. The PASID is released in __mmdrop(), while a sva domain > is released when on one is using it (the reference count is decremented > in iommu_sva_unbind_device()). > > Since the required info of PASID and sva domains is kept in struct > iommu_mm_data of a mm, use mm->iommu_mm field instead of the old pasid > field in mm struct. The sva domain list is protected by iommu_sva_lock. > > Besides, this patch removes mm_pasid_init(), as with the introduced > iommu_mm structure, initializing mm pasid in mm_init() is unnecessary. > > Signed-off-by: Tina Zhang <tina.zhang@intel.com> > --- > drivers/iommu/iommu-sva.c | 38 +++++++++++++++++++++++++------------- > include/linux/iommu.h | 10 +++------- > kernel/fork.c | 1 - > 3 files changed, 28 insertions(+), 21 deletions(-) > > diff --git a/drivers/iommu/iommu-sva.c b/drivers/iommu/iommu-sva.c > index 0a4a1ed40814..35366f51ad27 100644 > --- a/drivers/iommu/iommu-sva.c > +++ b/drivers/iommu/iommu-sva.c > @@ -15,6 +15,7 @@ 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) > { > + struct iommu_mm_data *iommu_mm = NULL; > int ret = 0; > > if (min == IOMMU_PASID_INVALID || > @@ -33,11 +34,22 @@ static int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t ma > goto out; > } > > + iommu_mm = kzalloc(sizeof(struct iommu_mm_data), GFP_KERNEL); > + if (!iommu_mm) { > + ret = -ENOMEM; > + goto out; > + } > + > ret = ida_alloc_range(&iommu_global_pasid_ida, min, max, GFP_KERNEL); > - if (ret < 0) > + if (ret < 0) { > + kfree(iommu_mm); > goto out; > + } > + > + iommu_mm->pasid = ret; > + mm->iommu_mm = iommu_mm; > + INIT_LIST_HEAD(&mm->iommu_mm->sva_domains); > > - mm->pasid = ret; > ret = 0; > out: > mutex_unlock(&iommu_sva_lock); > @@ -82,16 +94,12 @@ struct iommu_sva *iommu_sva_bind_device(struct device *dev, struct mm_struct *mm
Lets please rework this function into two parts
The first should be 'iommu_sva_alloc_domain()'
It should do the list searching and user management. The usual 'iommu_domain_free()' should be modified to clean it up.
Then you have the 'alloc global/enqcmd pasid' function
Then bind is just callling alloc sva domain, alloc global pasid, set_dev_pasid in a sequence.
It will make this much more understandable what all the parts are supposed to be doing.
Jason
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