Add a new sub-format ARM_64_LPAE_SPLIT_S1 to create and set up split
pagetables (TTBR0 and TTBR1). The initialization function sets up the
correct va_size and sign extension bits and programs the TCR registers.
Split pagetable formats use their own own map/unmap wrappers to ensure
that the correct pagetable is selected based on the incoming iova but
most of the heavy lifting is common to the other formats.

Signed-off-by: Jordan Crouse <jcro...@codeaurora.org>
---

 drivers/iommu/io-pgtable-arm.c | 261 +++++++++++++++++++++++++++++++++++++----
 drivers/iommu/io-pgtable.c     |   1 +
 include/linux/io-pgtable.h     |   2 +
 3 files changed, 240 insertions(+), 24 deletions(-)

diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
index 161a7d56..aec35e5 100644
--- a/drivers/iommu/io-pgtable-arm.c
+++ b/drivers/iommu/io-pgtable-arm.c
@@ -118,7 +118,12 @@
 #define ARM_LPAE_TCR_TG0_64K           (1 << 14)
 #define ARM_LPAE_TCR_TG0_16K           (2 << 14)
 
+#define ARM_LPAE_TCR_TG1_4K            (0 << 30)
+#define ARM_LPAE_TCR_TG1_64K           (1 << 30)
+#define ARM_LPAE_TCR_TG1_16K           (2 << 30)
+
 #define ARM_LPAE_TCR_SH0_SHIFT         12
+#define ARM_LPAE_TCR_SH1_SHIFT         28
 #define ARM_LPAE_TCR_SH0_MASK          0x3
 #define ARM_LPAE_TCR_SH_NS             0
 #define ARM_LPAE_TCR_SH_OS             2
@@ -126,6 +131,8 @@
 
 #define ARM_LPAE_TCR_ORGN0_SHIFT       10
 #define ARM_LPAE_TCR_IRGN0_SHIFT       8
+#define ARM_LPAE_TCR_ORGN1_SHIFT       26
+#define ARM_LPAE_TCR_IRGN1_SHIFT       24
 #define ARM_LPAE_TCR_RGN_MASK          0x3
 #define ARM_LPAE_TCR_RGN_NC            0
 #define ARM_LPAE_TCR_RGN_WBWA          1
@@ -136,6 +143,7 @@
 #define ARM_LPAE_TCR_SL0_MASK          0x3
 
 #define ARM_LPAE_TCR_T0SZ_SHIFT                0
+#define ARM_LPAE_TCR_T1SZ_SHIFT                16
 #define ARM_LPAE_TCR_SZ_MASK           0xf
 
 #define ARM_LPAE_TCR_PS_SHIFT          16
@@ -152,6 +160,14 @@
 #define ARM_LPAE_TCR_PS_48_BIT         0x5ULL
 #define ARM_LPAE_TCR_PS_52_BIT         0x6ULL
 
+#define ARM_LPAE_TCR_SEP_SHIFT         47
+#define ARM_LPAE_TCR_SEP_31            (0x0ULL << ARM_LPAE_TCR_SEP_SHIFT)
+#define ARM_LPAE_TCR_SEP_35            (0x1ULL << ARM_LPAE_TCR_SEP_SHIFT)
+#define ARM_LPAE_TCR_SEP_39            (0x2ULL << ARM_LPAE_TCR_SEP_SHIFT)
+#define ARM_LPAE_TCR_SEP_41            (0x3ULL << ARM_LPAE_TCR_SEP_SHIFT)
+#define ARM_LPAE_TCR_SEP_43            (0x4ULL << ARM_LPAE_TCR_SEP_SHIFT)
+#define ARM_LPAE_TCR_SEP_UPSTREAM      (0x7ULL << ARM_LPAE_TCR_SEP_SHIFT)
+
 #define ARM_LPAE_MAIR_ATTR_SHIFT(n)    ((n) << 3)
 #define ARM_LPAE_MAIR_ATTR_MASK                0xff
 #define ARM_LPAE_MAIR_ATTR_DEVICE      0x04
@@ -179,11 +195,12 @@ struct arm_lpae_io_pgtable {
        struct io_pgtable       iop;
 
        int                     levels;
+       u32                     sep;
        size_t                  pgd_size;
        unsigned long           pg_shift;
        unsigned long           bits_per_level;
 
-       void                    *pgd;
+       void                    *pgd[2];
 };
 
 typedef u64 arm_lpae_iopte;
@@ -426,7 +443,8 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(struct 
arm_lpae_io_pgtable *data,
        arm_lpae_iopte pte;
 
        if (data->iop.fmt == ARM_64_LPAE_S1 ||
-           data->iop.fmt == ARM_32_LPAE_S1) {
+           data->iop.fmt == ARM_32_LPAE_S1 ||
+           data->iop.fmt == ARM_64_LPAE_SPLIT_S1) {
                pte = ARM_LPAE_PTE_nG;
                if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
                        pte |= ARM_LPAE_PTE_AP_RDONLY;
@@ -470,11 +488,10 @@ static arm_lpae_iopte arm_lpae_prot_to_pte(struct 
arm_lpae_io_pgtable *data,
        return pte;
 }
 
-static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
-                       phys_addr_t paddr, size_t size, int iommu_prot)
+static int _arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
+                       phys_addr_t paddr, size_t size, int iommu_prot,
+                       arm_lpae_iopte *ptep)
 {
-       struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
-       arm_lpae_iopte *ptep = data->pgd;
        int ret, lvl = ARM_LPAE_START_LVL(data);
        arm_lpae_iopte prot;
 
@@ -497,12 +514,39 @@ static int arm_lpae_map(struct io_pgtable_ops *ops, 
unsigned long iova,
        return ret;
 }
 
+static int arm_lpae_split_map(struct io_pgtable_ops *ops, unsigned long iova,
+               phys_addr_t paddr, size_t size, int iommu_prot)
+{
+       struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
+       unsigned long mask = 1UL << data->sep;
+       arm_lpae_iopte *ptep;
+
+       if (iova & mask) {
+               ptep = data->pgd[1];
+               iova &= (mask - 1);
+       } else
+               ptep = data->pgd[0];
+
+       return _arm_lpae_map(data, iova, paddr, size, iommu_prot, ptep);
+}
+
+static int arm_lpae_map(struct io_pgtable_ops *ops, unsigned long iova,
+                       phys_addr_t paddr, size_t size, int iommu_prot)
+{
+       struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
+
+       return _arm_lpae_map(data, iova, paddr, size, iommu_prot, data->pgd[0]);
+}
+
 static void __arm_lpae_free_pgtable(struct arm_lpae_io_pgtable *data, int lvl,
                                    arm_lpae_iopte *ptep)
 {
        arm_lpae_iopte *start, *end;
        unsigned long table_size;
 
+       if (!ptep)
+               return;
+
        if (lvl == ARM_LPAE_START_LVL(data))
                table_size = data->pgd_size;
        else
@@ -532,7 +576,8 @@ static void arm_lpae_free_pgtable(struct io_pgtable *iop)
 {
        struct arm_lpae_io_pgtable *data = io_pgtable_to_data(iop);
 
-       __arm_lpae_free_pgtable(data, ARM_LPAE_START_LVL(data), data->pgd);
+       __arm_lpae_free_pgtable(data, ARM_LPAE_START_LVL(data), data->pgd[0]);
+       __arm_lpae_free_pgtable(data, ARM_LPAE_START_LVL(data), data->pgd[1]);
        kfree(data);
 }
 
@@ -643,11 +688,28 @@ static size_t __arm_lpae_unmap(struct arm_lpae_io_pgtable 
*data,
        return __arm_lpae_unmap(data, iova, size, lvl + 1, ptep);
 }
 
+static size_t arm_lpae_split_unmap(struct io_pgtable_ops *ops,
+                                  unsigned long iova, size_t size)
+{
+       struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
+       unsigned long mask = 1UL << data->sep;
+       arm_lpae_iopte *ptep;
+       int lvl = ARM_LPAE_START_LVL(data);
+
+       if (iova & mask) {
+               ptep = data->pgd[1];
+               iova &= (mask - 1);
+       } else
+               ptep = data->pgd[0];
+
+       return __arm_lpae_unmap(data, iova, size, lvl, ptep);
+}
+
 static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
                             size_t size)
 {
        struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
-       arm_lpae_iopte *ptep = data->pgd;
+       arm_lpae_iopte *ptep = data->pgd[0];
        int lvl = ARM_LPAE_START_LVL(data);
 
        if (WARN_ON(iova >= (1ULL << data->iop.cfg.ias)))
@@ -656,11 +718,11 @@ static size_t arm_lpae_unmap(struct io_pgtable_ops *ops, 
unsigned long iova,
        return __arm_lpae_unmap(data, iova, size, lvl, ptep);
 }
 
-static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
-                                        unsigned long iova)
+static phys_addr_t _arm_lpae_iova_to_phys(struct arm_lpae_io_pgtable *data,
+                                         unsigned long iova,
+                                         arm_lpae_iopte *ptep)
 {
-       struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
-       arm_lpae_iopte pte, *ptep = data->pgd;
+       arm_lpae_iopte pte;
        int lvl = ARM_LPAE_START_LVL(data);
 
        do {
@@ -692,6 +754,31 @@ static phys_addr_t arm_lpae_iova_to_phys(struct 
io_pgtable_ops *ops,
        return iopte_to_paddr(pte, data) | iova;
 }
 
+
+static phys_addr_t arm_lpae_split_iova_to_phys(struct io_pgtable_ops *ops,
+                                              unsigned long iova)
+{
+       struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
+       unsigned long mask = 1UL << data->sep;
+       arm_lpae_iopte *ptep;
+
+       if (iova & mask) {
+               ptep = data->pgd[1];
+               iova &= (mask - 1);
+       } else
+               ptep = data->pgd[0];
+
+       return _arm_lpae_iova_to_phys(data, iova, ptep);
+}
+
+static phys_addr_t arm_lpae_iova_to_phys(struct io_pgtable_ops *ops,
+                                        unsigned long iova)
+{
+       struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
+
+       return _arm_lpae_iova_to_phys(data, iova, data->pgd[0]);
+}
+
 static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
 {
        unsigned long granule, page_sizes;
@@ -771,6 +858,9 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
        pgd_bits = va_bits - (data->bits_per_level * (data->levels - 1));
        data->pgd_size = 1UL << (pgd_bits + ilog2(sizeof(arm_lpae_iopte)));
 
+       data->pgd[0] = NULL;
+       data->pgd[1] = NULL;
+
        data->iop.ops = (struct io_pgtable_ops) {
                .map            = arm_lpae_map,
                .unmap          = arm_lpae_unmap,
@@ -780,8 +870,8 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
        return data;
 }
 
-static struct io_pgtable *
-arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
+static struct arm_lpae_io_pgtable *
+_arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg)
 {
        u64 reg;
        struct arm_lpae_io_pgtable *data;
@@ -845,8 +935,6 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, 
void *cookie)
 
        reg |= (64ULL - cfg->ias) << ARM_LPAE_TCR_T0SZ_SHIFT;
 
-       /* Disable speculative walks through TTBR1 */
-       reg |= ARM_LPAE_TCR_EPD1;
        cfg->arm_lpae_s1_cfg.tcr = reg;
 
        /* MAIRs */
@@ -863,24 +951,143 @@ arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, 
void *cookie)
        cfg->arm_lpae_s1_cfg.mair[1] = 0;
 
        /* Looking good; allocate a pgd */
-       data->pgd = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
-       if (!data->pgd)
+       data->pgd[0] = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
+       if (!data->pgd[0])
                goto out_free_data;
 
        /* 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[0] = virt_to_phys(data->pgd[0]);
        cfg->arm_lpae_s1_cfg.ttbr[1] = 0;
+       return data;
+
+out_free_data:
+       kfree(data);
+       return NULL;
+}
+
+
+/* Allocate split pagetables */
+static struct io_pgtable *
+arm_64_lpae_alloc_pgtable_split_s1(struct io_pgtable_cfg *cfg, void *cookie)
+{
+       u64 reg;
+       struct arm_lpae_io_pgtable *data;
+       u32 sep;
+
+       /* Figure out what the sign extension bit should be */
+       switch (cfg->ias) {
+       case 32:
+       case 36:
+       case 40:
+       case 42:
+       case 44:
+               sep = cfg->ias - 1;
+               /* Adjust the address size to account for the extension bit */
+               cfg->ias--;
+               break;
+       case 48:
+               /* IAS of 48 is a special case, it has a dedicated bit */
+               sep = 48;
+               break;
+       default:
+               return NULL;
+       }
+
+       data = _arm_64_lpae_alloc_pgtable_s1(cfg);
+       if (!data)
+               return NULL;
+
+       /* Add the TTBR1 settings */
+       reg = cfg->arm_lpae_s1_cfg.tcr;
+
+       /* TCR */
+       reg |= (ARM_LPAE_TCR_SH_IS << ARM_LPAE_TCR_SH1_SHIFT) |
+             (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_IRGN1_SHIFT) |
+             (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_ORGN1_SHIFT);
+
+       switch (ARM_LPAE_GRANULE(data)) {
+       case SZ_4K:
+               reg |= ARM_LPAE_TCR_TG1_4K;
+               break;
+       case SZ_16K:
+               reg |= ARM_LPAE_TCR_TG1_16K;
+               break;
+       case SZ_64K:
+               reg |= ARM_LPAE_TCR_TG1_64K;
+               break;
+       }
+
+       reg |= (64ULL - cfg->ias) << ARM_LPAE_TCR_T1SZ_SHIFT;
+
+       switch (sep) {
+       case 31:
+               reg |= ARM_LPAE_TCR_SEP_31;
+               break;
+       case 35:
+               reg |= ARM_LPAE_TCR_SEP_35;
+               break;
+       case 39:
+               reg |= ARM_LPAE_TCR_SEP_39;
+               break;
+       case 41:
+               reg |= ARM_LPAE_TCR_SEP_41;
+               break;
+       case 43:
+               reg |= ARM_LPAE_TCR_SEP_43;
+               break;
+       case 48:
+               reg |= ARM_LPAE_TCR_SEP_UPSTREAM;
+               break;
+       }
+
+       cfg->arm_lpae_s1_cfg.tcr = reg;
+
+       /* Allocate the TTBR1 pagetable */
+       data->pgd[1] = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
+       if (!data->pgd[1])
+               goto out_free_data;
+
+       /* Override the data ops with split table specific ops */
+       data->iop.ops = (struct io_pgtable_ops) {
+               .map            = arm_lpae_split_map,
+               .unmap          = arm_lpae_split_unmap,
+               .iova_to_phys   = arm_lpae_split_iova_to_phys,
+       };
+
+       /*
+        * remember the sign extension bit, we'll need it later to figure out
+        * which pagetable to use
+        */
+       data->sep = sep;
+
+       /* Ensure the empty pgd is visible before any actual TTBR write */
+       wmb();
+
+       cfg->arm_lpae_s1_cfg.ttbr[1] = virt_to_phys(data->pgd[1]);
        return &data->iop;
 
 out_free_data:
+       __arm_lpae_free_pages(data->pgd[0], data->pgd_size, cfg);
        kfree(data);
        return NULL;
 }
 
 static struct io_pgtable *
+arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
+{
+       struct arm_lpae_io_pgtable *data;
+
+       data = _arm_64_lpae_alloc_pgtable_s1(cfg);
+       if (!data)
+               return NULL;
+
+       return &data->iop;
+}
+
+static struct io_pgtable *
 arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
 {
        u64 reg, sl;
@@ -960,15 +1167,15 @@ arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, 
void *cookie)
        cfg->arm_lpae_s2_cfg.vtcr = reg;
 
        /* Allocate pgd pages */
-       data->pgd = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
-       if (!data->pgd)
+       data->pgd[0] = __arm_lpae_alloc_pages(data->pgd_size, GFP_KERNEL, cfg);
+       if (!data->pgd[0])
                goto out_free_data;
 
        /* Ensure the empty pgd is visible before any actual TTBR write */
        wmb();
 
        /* VTTBR */
-       cfg->arm_lpae_s2_cfg.vttbr = virt_to_phys(data->pgd);
+       cfg->arm_lpae_s2_cfg.vttbr = virt_to_phys(data->pgd[0]);
        return &data->iop;
 
 out_free_data:
@@ -1041,6 +1248,11 @@ struct io_pgtable_init_fns 
io_pgtable_arm_64_lpae_s1_init_fns = {
        .free   = arm_lpae_free_pgtable,
 };
 
+struct io_pgtable_init_fns io_pgtable_arm_64_lpae_split_s1_init_fns = {
+       .alloc  = arm_64_lpae_alloc_pgtable_split_s1,
+       .free   = arm_lpae_free_pgtable,
+};
+
 struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns = {
        .alloc  = arm_64_lpae_alloc_pgtable_s2,
        .free   = arm_lpae_free_pgtable,
@@ -1095,9 +1307,9 @@ static void __init arm_lpae_dump_ops(struct 
io_pgtable_ops *ops)
 
        pr_err("cfg: pgsize_bitmap 0x%lx, ias %u-bit\n",
                cfg->pgsize_bitmap, cfg->ias);
-       pr_err("data: %d levels, 0x%zx pgd_size, %lu pg_shift, %lu 
bits_per_level, pgd @ %p\n",
+       pr_err("data: %d levels, 0x%zx pgd_size, %lu pg_shift, %lu 
bits_per_level, pgd @ %p %p\n",
                data->levels, data->pgd_size, data->pg_shift,
-               data->bits_per_level, data->pgd);
+               data->bits_per_level, data->pgd[0], data->pgd[1]);
 }
 
 #define __FAIL(ops, i) ({                                              \
@@ -1112,6 +1324,7 @@ static int __init arm_lpae_run_tests(struct 
io_pgtable_cfg *cfg)
        static const enum io_pgtable_fmt fmts[] = {
                ARM_64_LPAE_S1,
                ARM_64_LPAE_S2,
+               ARM_64_LPAE_SPLIT_S1,
        };
 
        int i, j;
diff --git a/drivers/iommu/io-pgtable.c b/drivers/iommu/io-pgtable.c
index ced53e5..ed1985f 100644
--- a/drivers/iommu/io-pgtable.c
+++ b/drivers/iommu/io-pgtable.c
@@ -20,6 +20,7 @@ io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] = {
        [ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
        [ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
        [ARM_MALI_LPAE] = &io_pgtable_arm_mali_lpae_init_fns,
+       [ARM_64_LPAE_SPLIT_S1] = &io_pgtable_arm_64_lpae_split_s1_init_fns,
 #endif
 #ifdef CONFIG_IOMMU_IO_PGTABLE_ARMV7S
        [ARM_V7S] = &io_pgtable_arm_v7s_init_fns,
diff --git a/include/linux/io-pgtable.h b/include/linux/io-pgtable.h
index b5a450a..2ed0e6a 100644
--- a/include/linux/io-pgtable.h
+++ b/include/linux/io-pgtable.h
@@ -10,6 +10,7 @@ enum io_pgtable_fmt {
        ARM_32_LPAE_S1,
        ARM_32_LPAE_S2,
        ARM_64_LPAE_S1,
+       ARM_64_LPAE_SPLIT_S1,
        ARM_64_LPAE_S2,
        ARM_V7S,
        ARM_MALI_LPAE,
@@ -211,6 +212,7 @@ extern struct io_pgtable_init_fns 
io_pgtable_arm_32_lpae_s1_init_fns;
 extern struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns;
 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns;
 extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s2_init_fns;
+extern struct io_pgtable_init_fns io_pgtable_arm_64_lpae_split_s1_init_fns;
 extern struct io_pgtable_init_fns io_pgtable_arm_v7s_init_fns;
 extern struct io_pgtable_init_fns io_pgtable_arm_mali_lpae_init_fns;
 
-- 
2.7.4

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