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From:   Tomasz Jeznach <tjeznach@rivosinc.com>
Date:   Thu, 20 Jul 2023 10:30:14 -0700
Message-ID: <CAH2o1u4q1=cKz7yFxKWrP2goypsxTxusYV_aSD-Os33bDZwepQ@mail.gmail.com>
Subject: Re: [PATCH 01/11] RISC-V: drivers/iommu: Add RISC-V IOMMU - Ziommu support.
To:     Baolu Lu <baolu.lu@linux.intel.com>
Cc:     Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Palmer Dabbelt <palmer@dabbelt.com>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Anup Patel <apatel@ventanamicro.com>,
        Sunil V L <sunilvl@ventanamicro.com>,
        Nick Kossifidis <mick@ics.forth.gr>,
        Sebastien Boeuf <seb@rivosinc.com>, iommu@lists.linux.dev,
        linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux@rivosinc.com
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On Thu, Jul 20, 2023 at 5:31=E2=80=AFAM Baolu Lu <baolu.lu@linux.intel.com>=
 wrote:
>
> On 2023/7/20 3:33, Tomasz Jeznach wrote:
> > +static void riscv_iommu_iotlb_sync_map(struct iommu_domain *iommu_doma=
in,
> > +                                    unsigned long iova, size_t size)
> > +{
> > +     unsigned long end =3D iova + size - 1;
> > +     /*
> > +      * Given we don't know the page size used by this range, we assum=
e the
> > +      * smallest page size to ensure all possible entries are flushed =
from
> > +      * the IOATC.
> > +      */
> > +     size_t pgsize =3D PAGE_SIZE;
> > +     riscv_iommu_flush_iotlb_range(iommu_domain, &iova, &end, &pgsize)=
;
> > +}
>
> Does RISC-V IOMMU require to invalidate the TLB cache after new mappings
> are created?
>

No. Only on unmapping / permission change.
Thanks for pointing this out.

> Best regards,
> baolu

regards,
- Tomasz