iommu/arm-smmu-v3: Drop __GFP_ZERO flag from DMA allocation

Since commit 518a2f19 ("dma-mapping: zero memory returned from
dma_alloc_*"), dma_alloc_* always initializes memory to zero, so there
is no need to use dma_zalloc_* or pass the __GFP_ZERO flag anymore.

The flag was introduced by commit 04fa26c7 ("iommu/arm-smmu: Convert
DMA buffer allocations to the managed API"), since the managed API
didn't provide a dmam_zalloc_coherent() function.
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Will Deacon <will@kernel.org>

drivers/iommu/arm-smmu-v3.c

@@ -1648,7 +1648,7 @@ static int arm_smmu_init_l2_strtab(struct arm_smmu_device *smmu, u32 sid)
 
 	desc->span = STRTAB_SPLIT + 1;
 	desc->l2ptr = dmam_alloc_coherent(smmu->dev, size, &desc->l2ptr_dma,
-					  GFP_KERNEL | __GFP_ZERO);
+					  GFP_KERNEL);
 	if (!desc->l2ptr) {
 		dev_err(smmu->dev,
 			"failed to allocate l2 stream table for SID %u\n",
@@ -2135,8 +2135,7 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
 		return asid;
 
 	cfg->cdptr = dmam_alloc_coherent(smmu->dev, CTXDESC_CD_DWORDS << 3,
-					 &cfg->cdptr_dma,
-					 GFP_KERNEL | __GFP_ZERO);
+					 &cfg->cdptr_dma, GFP_KERNEL);
 	if (!cfg->cdptr) {
 		dev_warn(smmu->dev, "failed to allocate context descriptor\n");
 		ret = -ENOMEM;
@@ -2871,7 +2870,7 @@ static int arm_smmu_init_strtab_2lvl(struct arm_smmu_device *smmu)
 
 	l1size = cfg->num_l1_ents * (STRTAB_L1_DESC_DWORDS << 3);
 	strtab = dmam_alloc_coherent(smmu->dev, l1size, &cfg->strtab_dma,
-				     GFP_KERNEL | __GFP_ZERO);
+				     GFP_KERNEL);
 	if (!strtab) {
 		dev_err(smmu->dev,
 			"failed to allocate l1 stream table (%u bytes)\n",
@@ -2898,7 +2897,7 @@ static int arm_smmu_init_strtab_linear(struct arm_smmu_device *smmu)
 
 	size = (1 << smmu->sid_bits) * (STRTAB_STE_DWORDS << 3);
 	strtab = dmam_alloc_coherent(smmu->dev, size, &cfg->strtab_dma,
-				     GFP_KERNEL | __GFP_ZERO);
+				     GFP_KERNEL);
 	if (!strtab) {
 		dev_err(smmu->dev,
 			"failed to allocate linear stream table (%u bytes)\n",