Messages in this thread | | | Date | Wed, 25 Nov 2020 11:06:02 +0530 | From | Sai Prakash Ranjan <> | Subject | Re: [PATCHv9 3/8] iommu/arm-smmu: Move non-strict mode to use io_pgtable_domain_attr |
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On 2020-11-25 03:09, Will Deacon wrote: > On Mon, Nov 23, 2020 at 10:35:56PM +0530, Sai Prakash Ranjan wrote: >> Now that we have a struct io_pgtable_domain_attr with quirks, >> use that for non_strict mode as well thereby removing the need >> for more members of arm_smmu_domain in the future. >> >> Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@codeaurora.org> >> --- >> drivers/iommu/arm/arm-smmu/arm-smmu.c | 8 +++----- >> drivers/iommu/arm/arm-smmu/arm-smmu.h | 1 - >> 2 files changed, 3 insertions(+), 6 deletions(-) >> >> diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c >> b/drivers/iommu/arm/arm-smmu/arm-smmu.c >> index 4b9b10fe50ed..f56f266ebdf7 100644 >> --- a/drivers/iommu/arm/arm-smmu/arm-smmu.c >> +++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c >> @@ -786,9 +786,6 @@ static int arm_smmu_init_domain_context(struct >> iommu_domain *domain, >> goto out_clear_smmu; >> } >> >> - if (smmu_domain->non_strict) >> - pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT; >> - >> if (smmu_domain->pgtbl_cfg.quirks) >> pgtbl_cfg.quirks |= smmu_domain->pgtbl_cfg.quirks; >> >> @@ -1527,7 +1524,8 @@ static int arm_smmu_domain_get_attr(struct >> iommu_domain *domain, >> case IOMMU_DOMAIN_DMA: >> switch (attr) { >> case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE: >> - *(int *)data = smmu_domain->non_strict; >> + if (smmu_domain->pgtbl_cfg.quirks & IO_PGTABLE_QUIRK_NON_STRICT) >> + *(int *)data = smmu_domain->pgtbl_cfg.quirks; > > I still don't think this is right :( > We need to set *data to 1 or 0 depending on whether or not the > non-strict > quirk is set, i.e: > > bool non_strict = smmu_domain->pgtbl_cfg.quirks & > IO_PGTABLE_QUIRK_NON_STRICT; > *(int *)data = non_strict; > > Your code above leaves *data uninitialised if non_strict is not set.
Ugh sorry, I should have looked at this some more before hurrying up to post, will fix it.
> >> return 0; >> default: >> return -ENODEV; >> @@ -1578,7 +1576,7 @@ static int arm_smmu_domain_set_attr(struct >> iommu_domain *domain, >> case IOMMU_DOMAIN_DMA: >> switch (attr) { >> case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE: >> - smmu_domain->non_strict = *(int *)data; >> + smmu_domain->pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT; > > And this is broken because if *data is 0, then you _set_ the quirk, > which is > the opposite of what we should be doing. > > In other words, although the implementation has changed, the semantics > have > not. >
Will fix this to have quirk set only when *data = 1 and unset in case of 0.
Thanks, Sai
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