Messages in this thread | | | Date | Fri, 28 Sep 2018 13:19:01 +0100 | From | Will Deacon <> | Subject | Re: [PATCH v8 5/7] iommu/arm-smmu-v3: Add support for non-strict mode |
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On Thu, Sep 20, 2018 at 05:10:25PM +0100, Robin Murphy wrote: > From: Zhen Lei <thunder.leizhen@huawei.com> > > Now that io-pgtable knows how to dodge strict TLB maintenance, all > that's left to do is bridge the gap between the IOMMU core requesting > DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE for default domains, and showing the > appropriate IO_PGTABLE_QUIRK_NON_STRICT flag to alloc_io_pgtable_ops(). > > Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> > [rm: convert to domain attribute, tweak commit message] > Signed-off-by: Robin Murphy <robin.murphy@arm.com> > --- > > v8: > - Use nested switches for attrs > - Document barrier semantics > > drivers/iommu/arm-smmu-v3.c | 79 ++++++++++++++++++++++++++----------- > 1 file changed, 56 insertions(+), 23 deletions(-) > > diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c > index f10c852479fc..db402e8b068b 100644 > --- a/drivers/iommu/arm-smmu-v3.c > +++ b/drivers/iommu/arm-smmu-v3.c > @@ -612,6 +612,7 @@ struct arm_smmu_domain { > struct mutex init_mutex; /* Protects smmu pointer */ > > struct io_pgtable_ops *pgtbl_ops; > + bool non_strict; > > enum arm_smmu_domain_stage stage; > union { > @@ -1407,6 +1408,12 @@ static void arm_smmu_tlb_inv_context(void *cookie) > cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid; > } > > + /* > + * NOTE: when io-pgtable is in non-strict mode, we may get here with > + * PTEs previously cleared by unmaps on the current CPU not yet visible > + * to the SMMU. We are relying on the DSB implicit in queue_inc_prod() > + * to guarantee those are observed before the TLBI. Do be careful, 007. > + */
Good, so you can ignore my comment on the previous patch :)
Will
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