linux-kernel - Re: [RESEND PATCH v17 2/5] iommu/arm-smmu: Invoke pm_runtime during probe, add/remove device

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Message-ID: <CAFp+6iEH7_XEcZNsbZfn6iBF5_o-ZKBj=DpturH7N85LU289qg@mail.gmail.com>
Date:   Thu, 22 Nov 2018 17:32:24 +0530
From:   Vivek Gautam <vivek.gautam@...eaurora.org>
To:     Will Deacon <will.deacon@....com>
Cc:     Mark Rutland <mark.rutland@....com>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@...r.kernel.org>, alex.williamson@...hat.com,
        Linux PM <linux-pm@...r.kernel.org>, sboyd@...nel.org,
        freedreno <freedreno@...ts.freedesktop.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        open list <linux-kernel@...r.kernel.org>,
        "list@....net:IOMMU DRIVERS <iommu@...ts.linux-foundation.org>, Joerg
        Roedel <joro@...tes.org>," <iommu@...ts.linux-foundation.org>,
        "robh+dt" <robh+dt@...nel.org>,
        linux-arm-msm <linux-arm-msm@...r.kernel.org>,
        Robin Murphy <robin.murphy@....com>
Subject: Re: [RESEND PATCH v17 2/5] iommu/arm-smmu: Invoke pm_runtime during
 probe, add/remove device

Hi Will,

On Wed, Nov 21, 2018 at 11:09 PM Will Deacon <will.deacon@....com> wrote:
>
> On Fri, Nov 16, 2018 at 04:54:27PM +0530, Vivek Gautam wrote:
> > From: Sricharan R <sricharan@...eaurora.org>
> >
> > The smmu device probe/remove and add/remove master device callbacks
> > gets called when the smmu is not linked to its master, that is without
> > the context of the master device. So calling runtime apis in those places
> > separately.
> > Global locks are also initialized before enabling runtime pm as the
> > runtime_resume() calls device_reset() which does tlb_sync_global()
> > that ultimately requires locks to be initialized.
> >
> > Signed-off-by: Sricharan R <sricharan@...eaurora.org>
> > [vivek: Cleanup pm runtime calls]
> > Signed-off-by: Vivek Gautam <vivek.gautam@...eaurora.org>
> > Reviewed-by: Tomasz Figa <tfiga@...omium.org>
> > Tested-by: Srinivas Kandagatla <srinivas.kandagatla@...aro.org>
> > Reviewed-by: Robin Murphy <robin.murphy@....com>
> > ---
> >  drivers/iommu/arm-smmu.c | 101 ++++++++++++++++++++++++++++++++++++++++++-----
> >  1 file changed, 91 insertions(+), 10 deletions(-)
>
> Given that you're doing the get/put in the TLBI ops unconditionally:
>
> >  static void arm_smmu_flush_iotlb_all(struct iommu_domain *domain)
> >  {
> >       struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
> > +     struct arm_smmu_device *smmu = smmu_domain->smmu;
> >
> > -     if (smmu_domain->tlb_ops)
> > +     if (smmu_domain->tlb_ops) {
> > +             arm_smmu_rpm_get(smmu);
> >               smmu_domain->tlb_ops->tlb_flush_all(smmu_domain);
> > +             arm_smmu_rpm_put(smmu);
> > +     }
> >  }
> >
> >  static void arm_smmu_iotlb_sync(struct iommu_domain *domain)
> >  {
> >       struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
> > +     struct arm_smmu_device *smmu = smmu_domain->smmu;
> >
> > -     if (smmu_domain->tlb_ops)
> > +     if (smmu_domain->tlb_ops) {
> > +             arm_smmu_rpm_get(smmu);
> >               smmu_domain->tlb_ops->tlb_sync(smmu_domain);
> > +             arm_smmu_rpm_put(smmu);
> > +     }
>
> Why do you need them around the map/unmap calls as well?

We still have .tlb_add_flush path?

Thanks
Vivek
>
> Will
> _______________________________________________
> iommu mailing list
> iommu@...ts.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/iommu

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