iommu/io-pgtable-arm: Rationalise MAIR handling

Between VMSAv8-64 and the various 32-bit formats, there is either one
64-bit MAIR or a pair of 32-bit MAIR0/MAIR1 or NMRR/PMRR registers.
As such, keeping two 64-bit values in io_pgtable_cfg has always been
overkill.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>

drivers/iommu/arm-smmu-v3.c

@@ -2172,7 +2172,7 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
 	cfg->cd.asid	= (u16)asid;
 	cfg->cd.ttbr	= pgtbl_cfg->arm_lpae_s1_cfg.ttbr[0];
 	cfg->cd.tcr	= pgtbl_cfg->arm_lpae_s1_cfg.tcr;
-	cfg->cd.mair	= pgtbl_cfg->arm_lpae_s1_cfg.mair[0];
+	cfg->cd.mair	= pgtbl_cfg->arm_lpae_s1_cfg.mair;
 	return 0;
 
 out_free_asid:

drivers/iommu/arm-smmu.c

@@ -552,8 +552,8 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain,
 			cb->mair[0] = pgtbl_cfg->arm_v7s_cfg.prrr;
 			cb->mair[1] = pgtbl_cfg->arm_v7s_cfg.nmrr;
 		} else {
-			cb->mair[0] = pgtbl_cfg->arm_lpae_s1_cfg.mair[0];
-			cb->mair[1] = pgtbl_cfg->arm_lpae_s1_cfg.mair[1];
+			cb->mair[0] = pgtbl_cfg->arm_lpae_s1_cfg.mair;
+			cb->mair[1] = pgtbl_cfg->arm_lpae_s1_cfg.mair >> 32;
 		}
 	}
 }

drivers/iommu/io-pgtable-arm.c

@@ -861,8 +861,7 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
 	      (ARM_LPAE_MAIR_ATTR_INC_OWBRWA
 	       << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_INC_OCACHE));
 
-	cfg->arm_lpae_s1_cfg.mair[0] = reg;
-	cfg->arm_lpae_s1_cfg.mair[1] = 0;
+	cfg->arm_lpae_s1_cfg.mair = reg;
 
 	/* Looking good; allocate a pgd */
 	data->pgd = __arm_lpae_alloc_pages(ARM_LPAE_PGD_SIZE(data),

drivers/iommu/ipmmu-vmsa.c

@@ -438,7 +438,7 @@ static void ipmmu_domain_setup_context(struct ipmmu_vmsa_domain *domain)
 
 	/* MAIR0 */
 	ipmmu_ctx_write_root(domain, IMMAIR0,
-			     domain->cfg.arm_lpae_s1_cfg.mair[0]);
+			     domain->cfg.arm_lpae_s1_cfg.mair);
 
 	/* IMBUSCR */
 	if (domain->mmu->features->setup_imbuscr)

drivers/iommu/qcom_iommu.c

@@ -284,9 +284,9 @@ static int qcom_iommu_init_domain(struct iommu_domain *domain,
 
 		/* MAIRs (stage-1 only) */
 		iommu_writel(ctx, ARM_SMMU_CB_S1_MAIR0,
-				pgtbl_cfg.arm_lpae_s1_cfg.mair[0]);
+				pgtbl_cfg.arm_lpae_s1_cfg.mair);
 		iommu_writel(ctx, ARM_SMMU_CB_S1_MAIR1,
-				pgtbl_cfg.arm_lpae_s1_cfg.mair[1]);
+				pgtbl_cfg.arm_lpae_s1_cfg.mair >> 32);
 
 		/* SCTLR */
 		reg = SCTLR_CFIE | SCTLR_CFRE | SCTLR_AFE | SCTLR_TRE |

include/linux/io-pgtable.h

@@ -102,7 +102,7 @@ struct io_pgtable_cfg {
 		struct {
 			u64	ttbr[2];
 			u64	tcr;
-			u64	mair[2];
+			u64	mair;
 		} arm_lpae_s1_cfg;
 
 		struct {