iommu/io-pgtable-arm: Rationalise TCR handling

Although it's conceptually nice for the io_pgtable_cfg to provide a
standard VMSA TCR value, the reality is that no VMSA-compliant IOMMU
looks exactly like an Arm CPU, and they all have various other TCR
controls which io-pgtable can't be expected to understand. Thus since
there is an expectation that drivers will have to add to the given TCR
value anyway, let's strip it down to just the essentials that are
directly relevant to io-pgtable's inner workings - namely the various
sizes and the walk attributes.

Tested-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[will: Add missing include of bitfield.h]
Signed-off-by: Will Deacon <will@kernel.org>

1 files changed, 9 insertions, 32 deletions

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index cf2ae065a6c2..d127974afdb7 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -260,27 +260,18 @@
 /* Context descriptor (stage-1 only) */
 #define CTXDESC_CD_DWORDS		8
 #define CTXDESC_CD_0_TCR_T0SZ		GENMASK_ULL(5, 0)
-#define ARM64_TCR_T0SZ			GENMASK_ULL(5, 0)
 #define CTXDESC_CD_0_TCR_TG0		GENMASK_ULL(7, 6)
-#define ARM64_TCR_TG0			GENMASK_ULL(15, 14)
 #define CTXDESC_CD_0_TCR_IRGN0		GENMASK_ULL(9, 8)
-#define ARM64_TCR_IRGN0			GENMASK_ULL(9, 8)
 #define CTXDESC_CD_0_TCR_ORGN0		GENMASK_ULL(11, 10)
-#define ARM64_TCR_ORGN0			GENMASK_ULL(11, 10)
 #define CTXDESC_CD_0_TCR_SH0		GENMASK_ULL(13, 12)
-#define ARM64_TCR_SH0			GENMASK_ULL(13, 12)
 #define CTXDESC_CD_0_TCR_EPD0		(1ULL << 14)
-#define ARM64_TCR_EPD0			(1ULL << 7)
 #define CTXDESC_CD_0_TCR_EPD1		(1ULL << 30)
-#define ARM64_TCR_EPD1			(1ULL << 23)
 
 #define CTXDESC_CD_0_ENDI		(1UL << 15)
 #define CTXDESC_CD_0_V			(1UL << 31)
 
 #define CTXDESC_CD_0_TCR_IPS		GENMASK_ULL(34, 32)
-#define ARM64_TCR_IPS			GENMASK_ULL(34, 32)
 #define CTXDESC_CD_0_TCR_TBI0		(1ULL << 38)
-#define ARM64_TCR_TBI0			(1ULL << 37)
 
 #define CTXDESC_CD_0_AA64		(1UL << 41)
 #define CTXDESC_CD_0_S			(1UL << 44)
@@ -291,10 +282,6 @@
 
 #define CTXDESC_CD_1_TTB0_MASK		GENMASK_ULL(51, 4)
 
-/* Convert between AArch64 (CPU) TCR format and SMMU CD format */
-#define ARM_SMMU_TCR2CD(tcr, fld)	FIELD_PREP(CTXDESC_CD_0_TCR_##fld, \
-					FIELD_GET(ARM64_TCR_##fld, tcr))
-
 /* Command queue */
 #define CMDQ_ENT_SZ_SHIFT		4
 #define CMDQ_ENT_DWORDS			((1 << CMDQ_ENT_SZ_SHIFT) >> 3)
@@ -1439,23 +1426,6 @@ static int arm_smmu_cmdq_issue_sync(struct arm_smmu_device *smmu)
 }
 
 /* Context descriptor manipulation functions */
-static u64 arm_smmu_cpu_tcr_to_cd(u64 tcr)
-{
-	u64 val = 0;
-
-	/* Repack the TCR. Just care about TTBR0 for now */
-	val |= ARM_SMMU_TCR2CD(tcr, T0SZ);
-	val |= ARM_SMMU_TCR2CD(tcr, TG0);
-	val |= ARM_SMMU_TCR2CD(tcr, IRGN0);
-	val |= ARM_SMMU_TCR2CD(tcr, ORGN0);
-	val |= ARM_SMMU_TCR2CD(tcr, SH0);
-	val |= ARM_SMMU_TCR2CD(tcr, EPD0);
-	val |= ARM_SMMU_TCR2CD(tcr, EPD1);
-	val |= ARM_SMMU_TCR2CD(tcr, IPS);
-
-	return val;
-}
-
 static void arm_smmu_write_ctx_desc(struct arm_smmu_device *smmu,
 				    struct arm_smmu_s1_cfg *cfg)
 {
@@ -1465,7 +1435,7 @@ static void arm_smmu_write_ctx_desc(struct arm_smmu_device *smmu,
 	 * We don't need to issue any invalidation here, as we'll invalidate
 	 * the STE when installing the new entry anyway.
 	 */
-	val = arm_smmu_cpu_tcr_to_cd(cfg->cd.tcr) |
+	val = cfg->cd.tcr |
 #ifdef __BIG_ENDIAN
 	      CTXDESC_CD_0_ENDI |
 #endif
@@ -2151,6 +2121,7 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
 	int asid;
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
+	typeof(&pgtbl_cfg->arm_lpae_s1_cfg.tcr) tcr = &pgtbl_cfg->arm_lpae_s1_cfg.tcr;
 
 	asid = arm_smmu_bitmap_alloc(smmu->asid_map, smmu->asid_bits);
 	if (asid < 0)
@@ -2167,7 +2138,13 @@ 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;
-	cfg->cd.tcr	= pgtbl_cfg->arm_lpae_s1_cfg.tcr;
+	cfg->cd.tcr	= FIELD_PREP(CTXDESC_CD_0_TCR_T0SZ, tcr->tsz) |
+			  FIELD_PREP(CTXDESC_CD_0_TCR_TG0, tcr->tg) |
+			  FIELD_PREP(CTXDESC_CD_0_TCR_IRGN0, tcr->irgn) |
+			  FIELD_PREP(CTXDESC_CD_0_TCR_ORGN0, tcr->orgn) |
+			  FIELD_PREP(CTXDESC_CD_0_TCR_SH0, tcr->sh) |
+			  FIELD_PREP(CTXDESC_CD_0_TCR_IPS, tcr->ips) |
+			  CTXDESC_CD_0_TCR_EPD1 | CTXDESC_CD_0_AA64;
 	cfg->cd.mair	= pgtbl_cfg->arm_lpae_s1_cfg.mair;
 	return 0;