iommu/arm-smmu: use relaxed accessors where possible

Apart from fault handling and page table manipulation, we don't care
about memory ordering between SMMU control registers and normal,
cacheable memory, so use the _relaxed I/O accessors wherever possible.

Signed-off-by: Will Deacon <will.deacon@arm.com>

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index abe83c3757ab03bbd61044be6ed02b8c7de5b8e7..293192150f5abdabf13bb46a312279887292047d 100644 (file)
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -778,7 +778,7 @@ static void arm_smmu_init_context_bank(struct arm_smmu_domain *smmu_domain)
 #ifdef __BIG_ENDIAN
        reg |= SCTLR_E;
 #endif
-       writel(reg, cb_base + ARM_SMMU_CB_SCTLR);
+       writel_relaxed(reg, cb_base + ARM_SMMU_CB_SCTLR);
 }
 
 static int arm_smmu_init_domain_context(struct iommu_domain *domain,
@@ -1595,7 +1595,7 @@ static void arm_smmu_device_reset(struct arm_smmu_device *smmu)
 
        /* Push the button */
        arm_smmu_tlb_sync(smmu);
-       writel(scr0, gr0_base + ARM_SMMU_GR0_sCR0);
+       writel_relaxed(scr0, gr0_base + ARM_SMMU_GR0_sCR0);
 }
 
 static int arm_smmu_id_size_to_bits(int size)
@@ -1928,7 +1928,7 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
                free_irq(smmu->irqs[i], smmu);
 
        /* Turn the thing off */
-       writel(sCR0_CLIENTPD, ARM_SMMU_GR0(smmu) + ARM_SMMU_GR0_sCR0);
+       writel_relaxed(sCR0_CLIENTPD, ARM_SMMU_GR0(smmu) + ARM_SMMU_GR0_sCR0);
        return 0;
 }