From: Will Deacon <will@kernel.org>
To: Prabhakar Kushwaha <prabhakar.pkin@gmail.com>
Cc: Ganapatrao Prabhakerrao Kulkarni <gkulkarni@marvell.com>,
Marc Zyngier <maz@kernel.org>,
Bhupesh Sharma <bhsharma@redhat.com>,
kexec mailing list <kexec@lists.infradead.org>,
Bjorn Helgaas <helgaas@kernel.org>,
Prabhakar Kushwaha <pkushwaha@marvell.com>,
Robin Murphy <robin.murphy@arm.com>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH][v2] iommu: arm-smmu-v3: Copy SMMU table for kdump kernel
Date: Thu, 21 May 2020 10:23:12 +0100 [thread overview]
Message-ID: <20200521092311.GB5091@willie-the-truck> (raw)
In-Reply-To: <CAJ2QiJLMKckbuAqJutAi_zUQqqaK5Mg_u5Q=gg-POSvmk8cT9g@mail.gmail.com>
On Tue, May 19, 2020 at 08:24:21AM +0530, Prabhakar Kushwaha wrote:
> On Mon, May 18, 2020 at 9:25 PM Will Deacon <will@kernel.org> wrote:
> > On Mon, May 11, 2020 at 07:46:06PM -0700, Prabhakar Kushwaha wrote:
> > > @@ -3272,6 +3281,23 @@ static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
> > > return 0;
> > > }
> > >
> > > +static void arm_smmu_copy_table(struct arm_smmu_device *smmu,
> > > + struct arm_smmu_strtab_cfg *cfg, u32 size)
> > > +{
> > > + struct arm_smmu_strtab_cfg rdcfg;
> > > +
> > > + rdcfg.strtab_dma = readq_relaxed(smmu->base + ARM_SMMU_STRTAB_BASE);
> > > + rdcfg.strtab_base_cfg = readq_relaxed(smmu->base
> > > + + ARM_SMMU_STRTAB_BASE_CFG);
> > > +
> > > + rdcfg.strtab_dma &= STRTAB_BASE_ADDR_MASK;
> > > + rdcfg.strtab = memremap(rdcfg.strtab_dma, size, MEMREMAP_WB);
> > > +
> > > + memcpy_fromio(cfg->strtab, rdcfg.strtab, size);
> > > +
>
> this need a fix. It should be memcpy.
>
> > > + cfg->strtab_base_cfg = rdcfg.strtab_base_cfg;
> >
> > Sorry, but this is unacceptable. These things were allocated by the DMA API
> > so you can't just memcpy them around and hope for the best.
> >
>
> I was referring copy_context_table() in drivers/iommu/intel-iommu.c.
> here i see usage of memremap and memcpy to copy older iommu table.
> did I take wrong reference?
>
> What kind of issue you are foreseeing in using memcpy(). May be we can
> try to find a solution.
Well the thing might not be cache-coherent to start with...
Will
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next prev parent reply other threads:[~2020-05-21 9:23 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-12 2:46 [PATCH][v2] iommu: arm-smmu-v3: Copy SMMU table for kdump kernel Prabhakar Kushwaha
2020-05-12 22:03 ` Bjorn Helgaas
2020-05-14 7:17 ` Prabhakar Kushwaha
2020-05-19 23:22 ` Bjorn Helgaas
2020-05-21 3:58 ` Prabhakar Kushwaha
2020-05-21 22:49 ` Bjorn Helgaas
2020-05-27 11:44 ` Prabhakar Kushwaha
2020-05-27 20:18 ` Bjorn Helgaas
2020-05-29 14:18 ` Prabhakar Kushwaha
2020-05-29 19:33 ` Bjorn Helgaas
2020-06-03 17:42 ` Prabhakar Kushwaha
2020-06-04 0:02 ` Bjorn Helgaas
2020-06-07 8:30 ` Prabhakar Kushwaha
2020-06-11 23:03 ` Bjorn Helgaas
2020-05-18 15:55 ` Will Deacon
2020-05-19 2:54 ` Prabhakar Kushwaha
2020-05-21 9:23 ` Will Deacon [this message]
2020-05-21 11:22 ` Prabhakar Kushwaha
2020-06-01 7:39 ` Will Deacon
2020-06-02 14:04 ` Prabhakar Kushwaha
2020-06-08 11:41 ` Will Deacon
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