[PATCH v2 1/1] iommu/arm-smmu-v3: Fix error case of range command

zhurui
2023-08-04T09:32:02Z

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;
+ else /* Convert page size of 12,14,16 (log2) to 1,2,3 */
+ cmd->tlbi.tg = (tg - 10) / 2;
+
/* range is num * 2^scale * pgsize */
inv_range = num << (scale + tg);

--
1.8.3.1