From: Jean-Philippe Brucker <jean-philippe@linaro.org>
To: Auger Eric <eric.auger@redhat.com>
Cc: fenghua.yu@intel.com, will@kernel.org, catalin.marinas@arm.com,
zhengxiang9@huawei.com, linux-mm@kvack.org,
iommu@lists.linux-foundation.org, zhangfei.gao@linaro.org,
robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH RESEND v9 03/13] iommu/sva: Add PASID helpers
Date: Thu, 17 Sep 2020 16:36:51 +0200 [thread overview]
Message-ID: <20200917143651.GB134903@myrica> (raw)
In-Reply-To: <dfdb8dbf-feaa-2c99-3fc8-1ee21515d7f1@redhat.com>
On Tue, Sep 08, 2020 at 09:45:02AM +0200, Auger Eric wrote:
> > +int iommu_sva_alloc_pasid(struct mm_struct *mm, ioasid_t min, ioasid_t max)
> > +{
> > + int ret = 0;
> > + ioasid_t pasid;
> > +
> > + if (min == INVALID_IOASID || max == INVALID_IOASID ||
> > + min == 0 || max < min)
> you may add a comment explaining why min == 0 is forbidden.
Right, I'll add to the function doc "@min must be greater than 0 because
0 indicates an unused mm->pasid."
> > + return -EINVAL;
> > +
> > + mutex_lock(&iommu_sva_lock);
> > + if (mm->pasid) {
> > + if (mm->pasid >= min && mm->pasid <= max)
> > + ioasid_get(mm->pasid);
> > + else
> > + ret = -EOVERFLOW;
> > + } else {
> > + pasid = ioasid_alloc(&iommu_sva_pasid, min, max, mm);
> > + if (pasid == INVALID_IOASID)
> > + ret = -ENOMEM;
> > + else
> > + mm->pasid = pasid;
> > + }
> > + mutex_unlock(&iommu_sva_lock);
> > + return ret;
> > +}
> > +EXPORT_SYMBOL_GPL(iommu_sva_alloc_pasid);
> > +
> > +/**
> > + * iommu_sva_free_pasid - Release the mm's PASID
> > + * @mm: the mm.
> > + *
> > + * Drop one reference to a PASID allocated with iommu_sva_alloc_pasid()
> > + */
> > +void iommu_sva_free_pasid(struct mm_struct *mm)
> > +{
> > + mutex_lock(&iommu_sva_lock);
> > + if (ioasid_put(mm->pasid))
> > + mm->pasid = 0;
> ditto: 0 versus INVALID_IOASID
> > + mutex_unlock(&iommu_sva_lock);
> > +}
> > +EXPORT_SYMBOL_GPL(iommu_sva_free_pasid);
> > +
> > +/* ioasid wants a void * argument */
> shouldn't it be:
> ioasid_find getter() requires a void *arg?
Ok
Thanks,
Jean
> > +static bool __mmget_not_zero(void *mm)
> > +{
> > + return mmget_not_zero(mm);
> > +}
> > +
> > +/**
> > + * iommu_sva_find() - Find mm associated to the given PASID
> > + * @pasid: Process Address Space ID assigned to the mm
> > + *
> > + * On success a reference to the mm is taken, and must be released with mmput().
> > + *
> > + * Returns the mm corresponding to this PASID, or an error if not found.
> > + */
> > +struct mm_struct *iommu_sva_find(ioasid_t pasid)
> > +{
> > + return ioasid_find(&iommu_sva_pasid, pasid, __mmget_not_zero);
> > +}
> > +EXPORT_SYMBOL_GPL(iommu_sva_find);
> >
> Thanks
>
> Eric
>
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next prev parent reply other threads:[~2020-09-17 14:37 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-17 17:15 [PATCH RESEND v9 00/13] iommu: Shared Virtual Addressing for SMMUv3 (PT sharing part) Jean-Philippe Brucker
2020-08-17 17:15 ` [PATCH RESEND v9 01/13] mm: Define pasid in mm Jean-Philippe Brucker
2020-08-17 17:15 ` [PATCH RESEND v9 02/13] iommu/ioasid: Add ioasid references Jean-Philippe Brucker
2020-09-08 9:52 ` Auger Eric
2020-08-17 17:15 ` [PATCH RESEND v9 03/13] iommu/sva: Add PASID helpers Jean-Philippe Brucker
2020-09-08 7:45 ` Auger Eric
2020-09-17 14:36 ` Jean-Philippe Brucker [this message]
2020-08-17 17:15 ` [PATCH RESEND v9 04/13] arm64: mm: Pin down ASIDs for sharing mm with devices Jean-Philippe Brucker
2020-08-17 17:15 ` [PATCH RESEND v9 05/13] iommu/io-pgtable-arm: Move some definitions to a header Jean-Philippe Brucker
2020-08-17 17:15 ` [PATCH RESEND v9 06/13] arm64: cpufeature: Export symbol read_sanitised_ftr_reg() Jean-Philippe Brucker
2020-08-17 17:15 ` [PATCH RESEND v9 07/13] iommu/arm-smmu-v3: Move definitions to a header Jean-Philippe Brucker
2020-09-08 9:16 ` Auger Eric
2020-08-17 17:15 ` [PATCH RESEND v9 08/13] iommu/arm-smmu-v3: Share process page tables Jean-Philippe Brucker
2020-09-08 7:41 ` Auger Eric
2020-09-17 14:37 ` Jean-Philippe Brucker
2020-08-17 17:15 ` [PATCH RESEND v9 09/13] iommu/arm-smmu-v3: Seize private ASID Jean-Philippe Brucker
2020-09-07 16:41 ` Auger Eric
2020-09-17 14:38 ` Jean-Philippe Brucker
2020-08-17 17:15 ` [PATCH RESEND v9 10/13] iommu/arm-smmu-v3: Check for SVA features Jean-Philippe Brucker
2020-09-08 9:38 ` Auger Eric
2020-09-17 14:39 ` Jean-Philippe Brucker
2020-08-17 17:15 ` [PATCH RESEND v9 11/13] iommu/arm-smmu-v3: Add SVA device feature Jean-Philippe Brucker
2020-09-08 9:46 ` Auger Eric
2020-09-17 14:40 ` Jean-Philippe Brucker
2020-08-17 17:15 ` [PATCH RESEND v9 12/13] iommu/arm-smmu-v3: Implement iommu_sva_bind/unbind() Jean-Philippe Brucker
2020-08-17 17:15 ` [PATCH RESEND v9 13/13] iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops Jean-Philippe Brucker
2020-09-04 9:08 ` [PATCH RESEND v9 00/13] iommu: Shared Virtual Addressing for SMMUv3 (PT sharing part) Joerg Roedel
2020-09-17 14:36 ` Jean-Philippe Brucker
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