Messages in this thread | | | Date | Fri, 4 Aug 2023 17:52:25 +0100 | From | Will Deacon <> | Subject | Re: [PATCH v2 1/1] iommu/arm-smmu-v3: Fix error case of range command |
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On Fri, Aug 04, 2023 at 05:31:20PM +0800, zhurui wrote: > When tg != 0 but ttl, scale, num all 0 in a range tlbi command, it > is reserved and will cause the CERROR_ILL error. This case means > that the size to be invalidated is only one page size, and the > range invalidation is meaningless here. So we set tg to 0 in this > case to do an non-range invalidation instead. > > Cc: Will Deacon <will@kernel.org> > Cc: Robin Murphy <robin.murphy@arm.com> > Cc: Joerg Roedel <joro@8bytes.org> > Cc: Lu Baolu <baolu.lu@linux.intel.com> > Cc: Jason Gunthorpe <jgg@ziepe.ca> > Cc: Yicong Yang <yangyicong@hisilicon.com> > Cc: Tomas Krcka <krckatom@amazon.de> > Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> > Cc: Nicolin Chen <nicolinc@nvidia.com> > Cc: Rui Zhu <zhurui3@huawei.com> > > Signed-off-by: Rui Zhu <zhurui3@huawei.com> > --- > ChangeLog: > v1-->v2: > 1. Change from "Revert" to modify the problematic case > > drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > index 9b0dc3505601..5e56c7e85819 100644 > --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c > @@ -1895,9 +1895,6 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd, > /* Get the leaf page size */ > tg = __ffs(smmu_domain->domain.pgsize_bitmap); > > - /* Convert page size of 12,14,16 (log2) to 1,2,3 */ > - cmd->tlbi.tg = (tg - 10) / 2; > - > /* > * Determine what level the granule is at. For non-leaf, io-pgtable > * assumes .tlb_flush_walk can invalidate multiple levels at once, > @@ -1930,6 +1927,12 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd, > num = (num_pages >> scale) & CMDQ_TLBI_RANGE_NUM_MAX; > cmd->tlbi.num = num - 1; > > + /* Prevent error caused by one page tlbi with leaf 0 */ > + if (scale == 0 && num == 1 && cmd->tlbi.leaf == 0) > + cmd->tlbi.tg = 0;
This should only be true for the last iteration, right (i.e. when num_pages == 1)? In which case, I'd prefer to leave the old code as-is and just add:
/* Single-page leaf invalidation requires a TG field of 0 */ if (num_pages == 1 && !cmd->tlbi.leaf) cmd->tlbi.tg = 0;
here.
Will
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