From c84c5ab76c9c04b5f1c8cc66ee9313198e89bb11 Mon Sep 17 00:00:00 2001
From: Jason Gunthorpe <jgg@nvidia.com>
Date: Mon, 10 Jun 2024 21:31:10 -0300
Subject: [PATCH] iommu/arm-smmu-v3: Do not zero the strtab twice
dmam_alloc_coherent() already returns zero'd memory so cfg->strtab.l1_desc
(the list of DMA addresses for the L2 entries) is already zero'd.
arm_smmu_init_l1_strtab() goes through and calls
arm_smmu_write_strtab_l1_desc() on the newly allocated (and zero'd) struct
arm_smmu_strtab_l1_desc, which ends up computing 'val = 0' and zeroing it
again.
Remove arm_smmu_init_l1_strtab() and just call devm_kcalloc() from
arm_smmu_init_strtab_2lvl to allocate the companion struct.
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/1-v2-318ed5f6983b+198f-smmuv3_tidy_jgg@nvidia.com
Signed-off-by: Will Deacon <will@kernel.org>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 26 +++++----------------
1 file changed, 6 insertions(+), 20 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 8c3031fe542b2..bb2d9b0c0f634 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -3523,25 +3523,6 @@ static int arm_smmu_init_queues(struct arm_smmu_device *smmu)
PRIQ_ENT_DWORDS, "priq");
}
-static int arm_smmu_init_l1_strtab(struct arm_smmu_device *smmu)
-{
- unsigned int i;
- struct arm_smmu_strtab_cfg *cfg = &smmu->strtab_cfg;
- void *strtab = smmu->strtab_cfg.strtab;
-
- cfg->l1_desc = devm_kcalloc(smmu->dev, cfg->num_l1_ents,
- sizeof(*cfg->l1_desc), GFP_KERNEL);
- if (!cfg->l1_desc)
- return -ENOMEM;
-
- for (i = 0; i < cfg->num_l1_ents; ++i) {
- arm_smmu_write_strtab_l1_desc(strtab, &cfg->l1_desc[i]);
- strtab += STRTAB_L1_DESC_DWORDS << 3;
- }
-
- return 0;
-}
-
static int arm_smmu_init_strtab_2lvl(struct arm_smmu_device *smmu)
{
void *strtab;
@@ -3577,7 +3558,12 @@ static int arm_smmu_init_strtab_2lvl(struct arm_smmu_device *smmu)
reg |= FIELD_PREP(STRTAB_BASE_CFG_SPLIT, STRTAB_SPLIT);
cfg->strtab_base_cfg = reg;
- return arm_smmu_init_l1_strtab(smmu);
+ cfg->l1_desc = devm_kcalloc(smmu->dev, cfg->num_l1_ents,
+ sizeof(*cfg->l1_desc), GFP_KERNEL);
+ if (!cfg->l1_desc)
+ return -ENOMEM;
+
+ return 0;
}
static int arm_smmu_init_strtab_linear(struct arm_smmu_device *smmu)
--
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