[PATCH v2 08/17] iommu/arm-smmu: Get rid of weird "atomic" write

From: Robin Murphy <robin.murphy@arm.com>
To: will@kernel.org
Cc: bjorn.andersson@linaro.org, iommu@lists.linux-foundation.org,
	gregory.clement@bootlin.com,
	linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 08/17] iommu/arm-smmu: Get rid of weird "atomic" write
Date: Thu, 15 Aug 2019 19:37:28 +0100	[thread overview]
Message-ID: <c578e786b3994bd21b174d9af44533ff082aff52.1565892337.git.robin.murphy@arm.com> (raw)
In-Reply-To: <cover.1565892337.git.robin.murphy@arm.com>

The smmu_write_atomic_lq oddity made some sense when the context
format was effectively tied to CONFIG_64BIT, but these days it's
simpler to just pick an explicit access size based on the format
for the one-and-a-half times we actually care.

Signed-off-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/arm-smmu.c | 23 +++++++----------------
 1 file changed, 7 insertions(+), 16 deletions(-)

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 5b12e96d7878..24b4de1a4185 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -83,17 +83,6 @@
 		((smmu->options & ARM_SMMU_OPT_SECURE_CFG_ACCESS)	\
 			? 0x400 : 0))
 
-/*
- * Some 64-bit registers only make sense to write atomically, but in such
- * cases all the data relevant to AArch32 formats lies within the lower word,
- * therefore this actually makes more sense than it might first appear.
- */
-#ifdef CONFIG_64BIT
-#define smmu_write_atomic_lq		writeq_relaxed
-#else
-#define smmu_write_atomic_lq		writel_relaxed
-#endif
-
 /* Translation context bank */
 #define ARM_SMMU_CB(smmu, n)	((smmu)->base + (((smmu)->numpage + (n)) << (smmu)->pgshift))
 
@@ -533,7 +522,10 @@ static void arm_smmu_tlb_inv_range_s2(unsigned long iova, size_t size,
 	reg += leaf ? ARM_SMMU_CB_S2_TLBIIPAS2L : ARM_SMMU_CB_S2_TLBIIPAS2;
 	iova >>= 12;
 	do {
-		smmu_write_atomic_lq(iova, reg);
+		if (smmu_domain->cfg.fmt == ARM_SMMU_CTX_FMT_AARCH64)
+			writeq_relaxed(iova, reg);
+		else
+			writel_relaxed(iova, reg);
 		iova += granule >> 12;
 	} while (size -= granule);
 }
@@ -1371,11 +1363,10 @@ static phys_addr_t arm_smmu_iova_to_phys_hard(struct iommu_domain *domain,
 	cb_base = ARM_SMMU_CB(smmu, cfg->cbndx);
 
 	spin_lock_irqsave(&smmu_domain->cb_lock, flags);
-	/* ATS1 registers can only be written atomically */
 	va = iova & ~0xfffUL;
-	if (smmu->version == ARM_SMMU_V2)
-		smmu_write_atomic_lq(va, cb_base + ARM_SMMU_CB_ATS1PR);
-	else /* Register is only 32-bit in v1 */
+	if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH64)
+		writeq_relaxed(va, cb_base + ARM_SMMU_CB_ATS1PR);
+	else
 		writel_relaxed(va, cb_base + ARM_SMMU_CB_ATS1PR);
 
 	if (readl_poll_timeout_atomic(cb_base + ARM_SMMU_CB_ATSR, tmp,
-- 
2.21.0.dirty

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