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Date:   Mon, 3 Apr 2023 13:55:04 -0700
From:   Jacob Pan <jacob.jun.pan@linux.intel.com>
To:     Baolu Lu <baolu.lu@linux.intel.com>
Cc:     LKML <linux-kernel@vger.kernel.org>, iommu@lists.linux.dev,
        Robin Murphy <robin.murphy@arm.com>,
        Jason Gunthorpe <jgg@nvidia.com>,
        Joerg Roedel <joro@8bytes.org>, dmaengine@vger.kernel.org,
        vkoul@kernel.org, Will Deacon <will@kernel.org>,
        David Woodhouse <dwmw2@infradead.org>,
        Raj Ashok <ashok.raj@intel.com>,
        "Tian, Kevin" <kevin.tian@intel.com>, Yi Liu <yi.l.liu@intel.com>,
        "Yu, Fenghua" <fenghua.yu@intel.com>,
        Dave Jiang <dave.jiang@intel.com>,
        Tony Luck <tony.luck@intel.com>,
        "Zanussi, Tom" <tom.zanussi@intel.com>,
        jacob.jun.pan@linux.intel.com
Subject: Re: [PATCH v3 3/7] iommu/sva: Support allocation of global PASIDs
 outside SVA
Message-ID: <20230403135504.2bd89822@jacob-builder>
In-Reply-To: <81fddd3e-bf6c-966a-b44b-b8a7c9c00591@linux.intel.com>
References: <20230331231137.1947675-1-jacob.jun.pan@linux.intel.com>
        <20230331231137.1947675-4-jacob.jun.pan@linux.intel.com>
        <81fddd3e-bf6c-966a-b44b-b8a7c9c00591@linux.intel.com>
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Hi Baolu,

On Sat, 1 Apr 2023 21:28:02 +0800, Baolu Lu <baolu.lu@linux.intel.com>
wrote:

> On 2023/4/1 7:11, Jacob Pan wrote:
> > 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 */  
> 
> I don't think the function prototypes of
> iommu_[alloc|free]_global_pasid() should be impacted by
> CONFIG_IOMMU_SVA. Or I may overlooked something?
you're right, the scope is beyond SVA now. It should be under
CONFIG_IOMMU_API, i think.

Thanks,

Jacob