TTBR1 values have so far been redundant since no users implement any
support for split address spaces. Crucially, though, one of the main
reasons for wanting to do so is to be able to manage each half entirely
independently, e.g. context-switching one set of mappings without
disturbing the other. Thus it seems unlikely that tying two tables
together in a single io_pgtable_cfg would ever be particularly desirable
or useful.

Streamline the configs to just a single conceptual TTBR value
representing the allocated table. This paves the way for future users to
support split address spaces by simply allocating a table and dealing
with the detailed TTBRn logistics themselves.

Signed-off-by: Robin Murphy <[email protected]>
---
 drivers/iommu/arm-smmu-v3.c        |  2 +-
 drivers/iommu/arm-smmu.c           |  9 ++++-----
 drivers/iommu/io-pgtable-arm-v7s.c | 16 +++++++---------
 drivers/iommu/io-pgtable-arm.c     |  7 +++----
 drivers/iommu/ipmmu-vmsa.c         |  2 +-
 drivers/iommu/msm_iommu.c          |  4 ++--
 drivers/iommu/mtk_iommu.c          |  4 ++--
 drivers/iommu/qcom_iommu.c         |  3 +--
 include/linux/io-pgtable.h         |  4 ++--
 9 files changed, 23 insertions(+), 28 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index 2a8db896d698..2e50cf49c3c4 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -1722,7 +1722,7 @@ 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.ttbr    = pgtbl_cfg->arm_lpae_s1_cfg.ttbr;
        cfg->cd.tcr     = pgtbl_cfg->arm_lpae_s1_cfg.tcr;
        cfg->cd.mair    = pgtbl_cfg->arm_lpae_s1_cfg.mair;
        return 0;
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 184ca41e9de7..19030c4b5904 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -473,13 +473,12 @@ static void arm_smmu_init_context_bank(struct 
arm_smmu_domain *smmu_domain,
        /* TTBRs */
        if (stage1) {
                if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH32_S) {
-                       cb->ttbr[0] = pgtbl_cfg->arm_v7s_cfg.ttbr[0];
-                       cb->ttbr[1] = pgtbl_cfg->arm_v7s_cfg.ttbr[1];
+                       cb->ttbr[0] = pgtbl_cfg->arm_v7s_cfg.ttbr;
+                       cb->ttbr[1] = 0;
                } else {
-                       cb->ttbr[0] = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[0];
+                       cb->ttbr[0] = pgtbl_cfg->arm_lpae_s1_cfg.ttbr;
                        cb->ttbr[0] |= FIELD_PREP(TTBRn_ASID, cfg->asid);
-                       cb->ttbr[1] = pgtbl_cfg->arm_lpae_s1_cfg.ttbr[1];
-                       cb->ttbr[1] |= FIELD_PREP(TTBRn_ASID, cfg->asid);
+                       cb->ttbr[1] = FIELD_PREP(TTBRn_ASID, cfg->asid);
                }
        } else {
                cb->ttbr[0] = pgtbl_cfg->arm_lpae_s2_cfg.vttbr;
diff --git a/drivers/iommu/io-pgtable-arm-v7s.c 
b/drivers/iommu/io-pgtable-arm-v7s.c
index 0fc8dfab2abf..7c80e9d00f73 100644
--- a/drivers/iommu/io-pgtable-arm-v7s.c
+++ b/drivers/iommu/io-pgtable-arm-v7s.c
@@ -775,15 +775,13 @@ static struct io_pgtable *arm_v7s_alloc_pgtable(struct 
io_pgtable_cfg *cfg,
        /* Ensure the empty pgd is visible before any actual TTBR write */
        wmb();
 
-       /* TTBRs */
-       cfg->arm_v7s_cfg.ttbr[0] = virt_to_phys(data->pgd) |
-                                  ARM_V7S_TTBR_S | ARM_V7S_TTBR_NOS |
-                                  (cfg->coherent_walk ?
-                                  (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) |
-                                   ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) :
-                                  (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) |
-                                   ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC)));
-       cfg->arm_v7s_cfg.ttbr[1] = 0;
+       /* TTBR */
+       cfg->arm_v7s_cfg.ttbr = virt_to_phys(data->pgd) | ARM_V7S_TTBR_S |
+                               (cfg->coherent_walk ? (ARM_V7S_TTBR_NOS |
+                                 ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_WBWA) |
+                                 ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_WBWA)) :
+                                (ARM_V7S_TTBR_IRGN_ATTR(ARM_V7S_RGN_NC) |
+                                 ARM_V7S_TTBR_ORGN_ATTR(ARM_V7S_RGN_NC)));
        return &data->iop;
 
 out_free_data:
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index c588ba0dd4d1..56e0921331c3 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -869,9 +869,8 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, 
void *cookie)
        /* Ensure the empty pgd is visible before any actual TTBR write */
        wmb();
 
-       /* TTBRs */
-       cfg->arm_lpae_s1_cfg.ttbr[0] = virt_to_phys(data->pgd);
-       cfg->arm_lpae_s1_cfg.ttbr[1] = 0;
+       /* TTBR */
+       cfg->arm_lpae_s1_cfg.ttbr = virt_to_phys(data->pgd);
        return &data->iop;
 
 out_free_data:
@@ -1024,7 +1023,7 @@ arm_mali_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg, 
void *cookie)
 
                /* Copy values as union fields overlap */
                mair = cfg->arm_lpae_s1_cfg.mair;
-               ttbr = cfg->arm_lpae_s1_cfg.ttbr[0];
+               ttbr = cfg->arm_lpae_s1_cfg.ttbr;
 
                cfg->arm_mali_lpae_cfg.memattr = mair;
                cfg->arm_mali_lpae_cfg.transtab = ttbr |
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index 9075e53a748b..180ab71d8542 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -416,7 +416,7 @@ static void ipmmu_domain_setup_context(struct 
ipmmu_vmsa_domain *domain)
        u32 tmp;
 
        /* TTBR0 */
-       ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr[0];
+       ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr;
        ipmmu_ctx_write_root(domain, IMTTLBR0, ttbr);
        ipmmu_ctx_write_root(domain, IMTTUBR0, ttbr >> 32);
 
diff --git a/drivers/iommu/msm_iommu.c b/drivers/iommu/msm_iommu.c
index b25e2eb9e038..fb6d406e0c52 100644
--- a/drivers/iommu/msm_iommu.c
+++ b/drivers/iommu/msm_iommu.c
@@ -270,8 +270,8 @@ static void __program_context(void __iomem *base, int ctx,
        SET_V2PCFG(base, ctx, 0x3);
 
        SET_TTBCR(base, ctx, priv->cfg.arm_v7s_cfg.tcr);
-       SET_TTBR0(base, ctx, priv->cfg.arm_v7s_cfg.ttbr[0]);
-       SET_TTBR1(base, ctx, priv->cfg.arm_v7s_cfg.ttbr[1]);
+       SET_TTBR0(base, ctx, priv->cfg.arm_v7s_cfg.ttbr);
+       SET_TTBR1(base, ctx, 0);
 
        /* Set prrr and nmrr */
        SET_PRRR(base, ctx, priv->cfg.arm_v7s_cfg.prrr);
diff --git a/drivers/iommu/mtk_iommu.c b/drivers/iommu/mtk_iommu.c
index 82e4be4dfdaf..ad644631780d 100644
--- a/drivers/iommu/mtk_iommu.c
+++ b/drivers/iommu/mtk_iommu.c
@@ -336,7 +336,7 @@ static int mtk_iommu_attach_device(struct iommu_domain 
*domain,
        /* Update the pgtable base address register of the M4U HW */
        if (!data->m4u_dom) {
                data->m4u_dom = dom;
-               writel(dom->cfg.arm_v7s_cfg.ttbr[0],
+               writel(dom->cfg.arm_v7s_cfg.ttbr,
                       data->base + REG_MMU_PT_BASE_ADDR);
        }
 
@@ -723,7 +723,7 @@ static int __maybe_unused mtk_iommu_resume(struct device 
*dev)
        writel_relaxed(reg->int_main_control, base + REG_MMU_INT_MAIN_CONTROL);
        writel_relaxed(reg->ivrp_paddr, base + REG_MMU_IVRP_PADDR);
        if (data->m4u_dom)
-               writel(data->m4u_dom->cfg.arm_v7s_cfg.ttbr[0],
+               writel(data->m4u_dom->cfg.arm_v7s_cfg.ttbr,
                       base + REG_MMU_PT_BASE_ADDR);
        return 0;
 }
diff --git a/drivers/iommu/qcom_iommu.c b/drivers/iommu/qcom_iommu.c
index 34bb357b3cfa..de55b6d82ef1 100644
--- a/drivers/iommu/qcom_iommu.c
+++ b/drivers/iommu/qcom_iommu.c
@@ -247,10 +247,9 @@ static int qcom_iommu_init_domain(struct iommu_domain 
*domain,
 
                /* TTBRs */
                iommu_writeq(ctx, ARM_SMMU_CB_TTBR0,
-                               pgtbl_cfg.arm_lpae_s1_cfg.ttbr[0] |
+                               pgtbl_cfg.arm_lpae_s1_cfg.ttbr |
                                FIELD_PREP(TTBRn_ASID, ctx->asid));
                iommu_writeq(ctx, ARM_SMMU_CB_TTBR1,
-                               pgtbl_cfg.arm_lpae_s1_cfg.ttbr[1] |
                                FIELD_PREP(TTBRn_ASID, ctx->asid));
 
                /* TCR */
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index a6c8aa204733..7a0905d7a006 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -90,7 +90,7 @@ struct io_pgtable_cfg {
        /* Low-level data specific to the table format */
        union {
                struct {
-                       u64     ttbr[2];
+                       u64     ttbr;
                        u64     tcr;
                        u64     mair;
                } arm_lpae_s1_cfg;
@@ -101,7 +101,7 @@ struct io_pgtable_cfg {
                } arm_lpae_s2_cfg;
 
                struct {
-                       u32     ttbr[2];
+                       u32     ttbr;
                        u32     tcr;
                        u32     nmrr;
                        u32     prrr;
-- 
2.21.0.dirty

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