Commit c84c5ab7 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Will Deacon
Browse files

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: default avatarNicolin Chen <nicolinc@nvidia.com>
Reviewed-by: default avatarMostafa Saleh <smostafa@google.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Reviewed-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Link: https://lore.kernel.org/r/1-v2-318ed5f6983b+198f-smmuv3_tidy_jgg@nvidia.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent f3b273b7

drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c

+6 −20
Original line number Diff line number Diff line
@@ -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)