Messages in this thread | | | Subject | Re: [PATCH v7 5/6] iommu/arm-smmu-v3: Add support for non-strict mode | From | Robin Murphy <> | Date | Tue, 18 Sep 2018 20:09:45 +0100 |
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On 2018-09-18 6:10 PM, Will Deacon wrote: > On Fri, Sep 14, 2018 at 03:30:23PM +0100, Robin Murphy wrote: >> From: Zhen Lei <thunder.leizhen@huawei.com> >> >> Dynamically choose strict or non-strict mode for page table config based >> on the iommu domain type. > > It's the domain type in conjunction with the attribute that determines > whether we use lazy or strict invalidation. > >> Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> >> [rm: convert to domain attribute] >> Signed-off-by: Robin Murphy <robin.murphy@arm.com> >> --- >> drivers/iommu/arm-smmu-v3.c | 30 ++++++++++++++++++++++++------ >> 1 file changed, 24 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c >> index f10c852479fc..7bbfa5f7ce8e 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 { >> @@ -1633,6 +1634,9 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain) >> if (smmu->features & ARM_SMMU_FEAT_COHERENCY) >> pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA; >> >> + if (smmu_domain->non_strict) >> + pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT; >> + >> pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain); >> if (!pgtbl_ops) >> return -ENOMEM; >> @@ -1934,13 +1938,17 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain, >> { >> struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); >> >> - if (domain->type != IOMMU_DOMAIN_UNMANAGED) >> - return -EINVAL; >> - >> switch (attr) { >> case DOMAIN_ATTR_NESTING: >> + if (domain->type != IOMMU_DOMAIN_UNMANAGED) >> + return -EINVAL; >> *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED); >> return 0; >> + case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE: >> + if (domain->type != IOMMU_DOMAIN_DMA) >> + return -EINVAL; >> + *(int *)data = smmu_domain->non_strict; >> + return 0; >> default: >> return -ENODEV; > > Hmm, there's a change in behaviour here (and also in the set function) > which is that unknown attributes now return -ENODEV for managed domains > instead of -EINVAL. I don't know if that's a problem, but I'd be inclined > to switch on the domain type and then have a nested switch for the supported > attributes.
Sure, a nested switch did actually cross my mind, but I was worried it might be a little boilerplate-heavy since there's still only one of each case (and this quick'n'dirty copy-paste job didn't need any thought...)
If that's your preference too, though, I'll respin both driver patches that way.
Robin.
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