iommu: add ARM LPAE page table allocator
authorWill Deacon <will.deacon@arm.com>
Fri, 14 Nov 2014 17:18:23 +0000 (17:18 +0000)
committerWill Deacon <will.deacon@arm.com>
Mon, 19 Jan 2015 14:46:44 +0000 (14:46 +0000)
A number of IOMMUs found in ARM SoCs can walk architecture-compatible
page tables.

This patch adds a generic allocator for Stage-1 and Stage-2 v7/v8
long-descriptor page tables. 4k, 16k and 64k pages are supported, with
up to 4-levels of walk to cover a 48-bit address space.

Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
MAINTAINERS
drivers/iommu/Kconfig
drivers/iommu/Makefile
drivers/iommu/io-pgtable-arm.c [new file with mode: 0644]
drivers/iommu/io-pgtable.c
drivers/iommu/io-pgtable.h

index 3589d67437f867e121bc36b0ff2b92e758499c04..00b27863384e6258ca096dd694878f40e15c1b1c 100644 (file)
@@ -1589,6 +1589,7 @@ M:        Will Deacon <will.deacon@arm.com>
 L:     linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 S:     Maintained
 F:     drivers/iommu/arm-smmu.c
+F:     drivers/iommu/io-pgtable-arm.c
 
 ARM64 PORT (AARCH64 ARCHITECTURE)
 M:     Catalin Marinas <catalin.marinas@arm.com>
index 3faaa41db8ffd691418d6cac2b7744e36c4f374e..306454fbc52d7dab0464976f44ebcc237a54cd2b 100644 (file)
@@ -19,6 +19,15 @@ menu "Generic IOMMU Pagetable Support"
 config IOMMU_IO_PGTABLE
        bool
 
+config IOMMU_IO_PGTABLE_LPAE
+       bool "ARMv7/v8 Long Descriptor Format"
+       select IOMMU_IO_PGTABLE
+       help
+         Enable support for the ARM long descriptor pagetable format.
+         This allocator supports 4K/2M/1G, 16K/32M and 64K/512M page
+         sizes at both stage-1 and stage-2, as well as address spaces
+         up to 48-bits in size.
+
 endmenu
 
 config OF_IOMMU
index 701c9516e2ae182a95b79902c69a7e624b4eb40f..d6889b487d5571ef002bde7a87f3d24cb430e14a 100644 (file)
@@ -2,6 +2,7 @@ obj-$(CONFIG_IOMMU_API) += iommu.o
 obj-$(CONFIG_IOMMU_API) += iommu-traces.o
 obj-$(CONFIG_IOMMU_API) += iommu-sysfs.o
 obj-$(CONFIG_IOMMU_IO_PGTABLE) += io-pgtable.o
+obj-$(CONFIG_IOMMU_IO_PGTABLE_LPAE) += io-pgtable-arm.o
 obj-$(CONFIG_OF_IOMMU) += of_iommu.o
 obj-$(CONFIG_MSM_IOMMU) += msm_iommu.o msm_iommu_dev.o
 obj-$(CONFIG_AMD_IOMMU) += amd_iommu.o amd_iommu_init.o
diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c
new file mode 100644 (file)
index 0000000..dbe6178
--- /dev/null
@@ -0,0 +1,781 @@
+/*
+ * CPU-agnostic ARM page table allocator.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Copyright (C) 2014 ARM Limited
+ *
+ * Author: Will Deacon <will.deacon@arm.com>
+ */
+
+#define pr_fmt(fmt)    "arm-lpae io-pgtable: " fmt
+
+#include <linux/iommu.h>
+#include <linux/kernel.h>
+#include <linux/sizes.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include "io-pgtable.h"
+
+#define ARM_LPAE_MAX_ADDR_BITS         48
+#define ARM_LPAE_S2_MAX_CONCAT_PAGES   16
+#define ARM_LPAE_MAX_LEVELS            4
+
+/* Struct accessors */
+#define io_pgtable_to_data(x)                                          \
+       container_of((x), struct arm_lpae_io_pgtable, iop)
+
+#define io_pgtable_ops_to_pgtable(x)                                   \
+       container_of((x), struct io_pgtable, ops)
+
+#define io_pgtable_ops_to_data(x)                                      \
+       io_pgtable_to_data(io_pgtable_ops_to_pgtable(x))
+
+/*
+ * For consistency with the architecture, we always consider
+ * ARM_LPAE_MAX_LEVELS levels, with the walk starting at level n >=0
+ */
+#define ARM_LPAE_START_LVL(d)          (ARM_LPAE_MAX_LEVELS - (d)->levels)
+
+/*
+ * Calculate the right shift amount to get to the portion describing level l
+ * in a virtual address mapped by the pagetable in d.
+ */
+#define ARM_LPAE_LVL_SHIFT(l,d)                                                \
+       ((((d)->levels - ((l) - ARM_LPAE_START_LVL(d) + 1))             \
+         * (d)->bits_per_level) + (d)->pg_shift)
+
+#define ARM_LPAE_PAGES_PER_PGD(d)      ((d)->pgd_size >> (d)->pg_shift)
+
+/*
+ * Calculate the index at level l used to map virtual address a using the
+ * pagetable in d.
+ */
+#define ARM_LPAE_PGD_IDX(l,d)                                          \
+       ((l) == ARM_LPAE_START_LVL(d) ? ilog2(ARM_LPAE_PAGES_PER_PGD(d)) : 0)
+
+#define ARM_LPAE_LVL_IDX(a,l,d)                                                \
+       (((a) >> ARM_LPAE_LVL_SHIFT(l,d)) &                             \
+        ((1 << ((d)->bits_per_level + ARM_LPAE_PGD_IDX(l,d))) - 1))
+
+/* Calculate the block/page mapping size at level l for pagetable in d. */
+#define ARM_LPAE_BLOCK_SIZE(l,d)                                       \
+       (1 << (ilog2(sizeof(arm_lpae_iopte)) +                          \
+               ((ARM_LPAE_MAX_LEVELS - (l)) * (d)->bits_per_level)))
+
+/* Page table bits */
+#define ARM_LPAE_PTE_TYPE_SHIFT                0
+#define ARM_LPAE_PTE_TYPE_MASK         0x3
+
+#define ARM_LPAE_PTE_TYPE_BLOCK                1
+#define ARM_LPAE_PTE_TYPE_TABLE                3
+#define ARM_LPAE_PTE_TYPE_PAGE         3
+
+#define ARM_LPAE_PTE_XN                        (((arm_lpae_iopte)3) << 53)
+#define ARM_LPAE_PTE_AF                        (((arm_lpae_iopte)1) << 10)
+#define ARM_LPAE_PTE_SH_NS             (((arm_lpae_iopte)0) << 8)
+#define ARM_LPAE_PTE_SH_OS             (((arm_lpae_iopte)2) << 8)
+#define ARM_LPAE_PTE_SH_IS             (((arm_lpae_iopte)3) << 8)
+#define ARM_LPAE_PTE_VALID             (((arm_lpae_iopte)1) << 0)
+
+#define ARM_LPAE_PTE_ATTR_LO_MASK      (((arm_lpae_iopte)0x3ff) << 2)
+/* Ignore the contiguous bit for block splitting */
+#define ARM_LPAE_PTE_ATTR_HI_MASK      (((arm_lpae_iopte)6) << 52)
+#define ARM_LPAE_PTE_ATTR_MASK         (ARM_LPAE_PTE_ATTR_LO_MASK |    \
+                                        ARM_LPAE_PTE_ATTR_HI_MASK)
+
+/* Stage-1 PTE */
+#define ARM_LPAE_PTE_AP_UNPRIV         (((arm_lpae_iopte)1) << 6)
+#define ARM_LPAE_PTE_AP_RDONLY         (((arm_lpae_iopte)2) << 6)
+#define ARM_LPAE_PTE_ATTRINDX_SHIFT    2
+#define ARM_LPAE_PTE_nG                        (((arm_lpae_iopte)1) << 11)
+
+/* Stage-2 PTE */
+#define ARM_LPAE_PTE_HAP_FAULT         (((arm_lpae_iopte)0) << 6)
+#define ARM_LPAE_PTE_HAP_READ          (((arm_lpae_iopte)1) << 6)
+#define ARM_LPAE_PTE_HAP_WRITE         (((arm_lpae_iopte)2) << 6)
+#define ARM_LPAE_PTE_MEMATTR_OIWB      (((arm_lpae_iopte)0xf) << 2)
+#define ARM_LPAE_PTE_MEMATTR_NC                (((arm_lpae_iopte)0x5) << 2)
+#define ARM_LPAE_PTE_MEMATTR_DEV       (((arm_lpae_iopte)0x1) << 2)
+
+/* Register bits */
+#define ARM_32_LPAE_TCR_EAE            (1 << 31)
+#define ARM_64_LPAE_S2_TCR_RES1                (1 << 31)
+
+#define ARM_LPAE_TCR_TG0_4K            (0 << 14)
+#define ARM_LPAE_TCR_TG0_64K           (1 << 14)
+#define ARM_LPAE_TCR_TG0_16K           (2 << 14)
+
+#define ARM_LPAE_TCR_SH0_SHIFT         12
+#define ARM_LPAE_TCR_SH0_MASK          0x3
+#define ARM_LPAE_TCR_SH_NS             0
+#define ARM_LPAE_TCR_SH_OS             2
+#define ARM_LPAE_TCR_SH_IS             3
+
+#define ARM_LPAE_TCR_ORGN0_SHIFT       10
+#define ARM_LPAE_TCR_IRGN0_SHIFT       8
+#define ARM_LPAE_TCR_RGN_MASK          0x3
+#define ARM_LPAE_TCR_RGN_NC            0
+#define ARM_LPAE_TCR_RGN_WBWA          1
+#define ARM_LPAE_TCR_RGN_WT            2
+#define ARM_LPAE_TCR_RGN_WB            3
+
+#define ARM_LPAE_TCR_SL0_SHIFT         6
+#define ARM_LPAE_TCR_SL0_MASK          0x3
+
+#define ARM_LPAE_TCR_T0SZ_SHIFT                0
+#define ARM_LPAE_TCR_SZ_MASK           0xf
+
+#define ARM_LPAE_TCR_PS_SHIFT          16
+#define ARM_LPAE_TCR_PS_MASK           0x7
+
+#define ARM_LPAE_TCR_IPS_SHIFT         32
+#define ARM_LPAE_TCR_IPS_MASK          0x7
+
+#define ARM_LPAE_TCR_PS_32_BIT         0x0ULL
+#define ARM_LPAE_TCR_PS_36_BIT         0x1ULL
+#define ARM_LPAE_TCR_PS_40_BIT         0x2ULL
+#define ARM_LPAE_TCR_PS_42_BIT         0x3ULL
+#define ARM_LPAE_TCR_PS_44_BIT         0x4ULL
+#define ARM_LPAE_TCR_PS_48_BIT         0x5ULL
+
+#define ARM_LPAE_MAIR_ATTR_SHIFT(n)    ((n) << 3)
+#define ARM_LPAE_MAIR_ATTR_MASK                0xff
+#define ARM_LPAE_MAIR_ATTR_DEVICE      0x04
+#define ARM_LPAE_MAIR_ATTR_NC          0x44
+#define ARM_LPAE_MAIR_ATTR_WBRWA       0xff
+#define ARM_LPAE_MAIR_ATTR_IDX_NC      0
+#define ARM_LPAE_MAIR_ATTR_IDX_CACHE   1
+#define ARM_LPAE_MAIR_ATTR_IDX_DEV     2
+
+/* IOPTE accessors */
+#define iopte_deref(pte,d)                                     \
+       (__va((pte) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1)    \
+       & ~((1ULL << (d)->pg_shift) - 1)))
+
+#define iopte_type(pte,l)                                      \
+       (((pte) >> ARM_LPAE_PTE_TYPE_SHIFT) & ARM_LPAE_PTE_TYPE_MASK)
+
+#define iopte_prot(pte)        ((pte) & ARM_LPAE_PTE_ATTR_MASK)
+
+#define iopte_leaf(pte,l)                                      \
+       (l == (ARM_LPAE_MAX_LEVELS - 1) ?                       \
+               (iopte_type(pte,l) == ARM_LPAE_PTE_TYPE_PAGE) : \
+               (iopte_type(pte,l) == ARM_LPAE_PTE_TYPE_BLOCK))
+
+#define iopte_to_pfn(pte,d)                                    \
+       (((pte) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1)) >> (d)->pg_shift)
+
+#define pfn_to_iopte(pfn,d)                                    \
+       (((pfn) << (d)->pg_shift) & ((1ULL << ARM_LPAE_MAX_ADDR_BITS) - 1))
+
+struct arm_lpae_io_pgtable {
+       struct io_pgtable       iop;
+
+       int                     levels;
+       size_t                  pgd_size;
+       unsigned long           pg_shift;
+       unsigned long           bits_per_level;
+
+       void                    *pgd;
+};
+
+typedef u64 arm_lpae_iopte;
+
+static int arm_lpae_init_pte(struct arm_lpae_io_pgtable *data,
+                            unsigned long iova, phys_addr_t paddr,
+                            arm_lpae_iopte prot, int lvl,
+                            arm_lpae_iopte *ptep)
+{
+       arm_lpae_iopte pte = prot;
+
+       /* We require an unmap first */
+       if (WARN_ON(iopte_leaf(*ptep, lvl)))
+               return -EEXIST;
+
+       if (lvl == ARM_LPAE_MAX_LEVELS - 1)
+               pte |= ARM_LPAE_PTE_TYPE_PAGE;
+       else
+               pte |= ARM_LPAE_PTE_TYPE_BLOCK;
+
+       pte |= ARM_LPAE_PTE_AF | ARM_LPAE_PTE_SH_IS;
+       pte |= pfn_to_iopte(paddr >> data->pg_shift, data);
+
+       *ptep = pte;
+       data->iop.cfg.tlb->flush_pgtable(ptep, sizeof(*ptep), data->iop.cookie);
+       return 0;
+}
+
+static int __arm_lpae_map(struct arm_lpae_io_pgtable *data, unsigned long iova,
+                         phys_addr_t paddr, size_t size, arm_lpae_iopte prot,
+                         int lvl, arm_lpae_iopte *ptep)
+{
+       arm_lpae_iopte *cptep, pte;
+       void *cookie = data->iop.cookie;
+       size_t block_size = ARM_LPAE_BLOCK_SIZE(lvl, data);
+
+       /* Find our entry at the current level */
+       ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
+
+       /* If we can install a leaf entry at this level, then do so */
+       if (size == block_size && (size & data->iop.cfg.pgsize_bitmap))
+               return arm_lpae_init_pte(data, iova, paddr, prot, lvl, ptep);
+
+       /* We can't allocate tables at the final level */
+       if (WARN_ON(lvl >= ARM_LPAE_MAX_LEVELS - 1))
+               return -EINVAL;
+
+       /* Grab a pointer to the next level */
+       pte = *ptep;
+       if (!pte) {
+               cptep = alloc_pages_exact(1UL << data->pg_shift,
+                                        GFP_ATOMIC | __GFP_ZERO);
+               if (!cptep)
+                       return -ENOMEM;
+
+               data->iop.cfg.tlb->flush_pgtable(cptep, 1UL << data->pg_shift,
+                                                cookie);
+               pte = __pa(cptep) | ARM_LPAE_PTE_TYPE_TABLE;
+               *ptep = pte;
+               data->iop.cfg.tlb->flush_pgtable(ptep, sizeof(*ptep), cookie);
+       } else {
+               cptep = iopte_deref(pte, data);
+       }
+
+       /* Rinse, repeat */
+       return __arm_lpae_map(data, iova, paddr, size, prot, lvl + 1, cptep);
+}
+
+static arm_lpae_iopte arm_lpae_prot_to_pte(struct arm_lpae_io_pgtable *data,
+                                          int prot)
+{
+       arm_lpae_iopte pte;
+
+       if (data->iop.fmt == ARM_64_LPAE_S1 ||
+           data->iop.fmt == ARM_32_LPAE_S1) {
+               pte = ARM_LPAE_PTE_AP_UNPRIV | ARM_LPAE_PTE_nG;
+
+               if (!(prot & IOMMU_WRITE) && (prot & IOMMU_READ))
+                       pte |= ARM_LPAE_PTE_AP_RDONLY;
+
+               if (prot & IOMMU_CACHE)
+                       pte |= (ARM_LPAE_MAIR_ATTR_IDX_CACHE
+                               << ARM_LPAE_PTE_ATTRINDX_SHIFT);
+       } else {
+               pte = ARM_LPAE_PTE_HAP_FAULT;
+               if (prot & IOMMU_READ)
+                       pte |= ARM_LPAE_PTE_HAP_READ;
+               if (prot & IOMMU_WRITE)
+                       pte |= ARM_LPAE_PTE_HAP_WRITE;
+               if (prot & IOMMU_CACHE)
+                       pte |= ARM_LPAE_PTE_MEMATTR_OIWB;
+               else
+                       pte |= ARM_LPAE_PTE_MEMATTR_NC;
+       }
+
+       if (prot & IOMMU_NOEXEC)
+               pte |= ARM_LPAE_PTE_XN;
+
+       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)
+{
+       struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
+       arm_lpae_iopte *ptep = data->pgd;
+       int lvl = ARM_LPAE_START_LVL(data);
+       arm_lpae_iopte prot;
+
+       /* If no access, then nothing to do */
+       if (!(iommu_prot & (IOMMU_READ | IOMMU_WRITE)))
+               return 0;
+
+       prot = arm_lpae_prot_to_pte(data, iommu_prot);
+       return __arm_lpae_map(data, iova, paddr, size, prot, lvl, ptep);
+}
+
+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;
+
+       /* Only leaf entries at the last level */
+       if (lvl == ARM_LPAE_MAX_LEVELS - 1)
+               return;
+
+       if (lvl == ARM_LPAE_START_LVL(data))
+               table_size = data->pgd_size;
+       else
+               table_size = 1UL << data->pg_shift;
+
+       start = ptep;
+       end = (void *)ptep + table_size;
+
+       while (ptep != end) {
+               arm_lpae_iopte pte = *ptep++;
+
+               if (!pte || iopte_leaf(pte, lvl))
+                       continue;
+
+               __arm_lpae_free_pgtable(data, lvl + 1, iopte_deref(pte, data));
+       }
+
+       free_pages_exact(start, table_size);
+}
+
+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);
+       kfree(data);
+}
+
+static int arm_lpae_split_blk_unmap(struct arm_lpae_io_pgtable *data,
+                                   unsigned long iova, size_t size,
+                                   arm_lpae_iopte prot, int lvl,
+                                   arm_lpae_iopte *ptep, size_t blk_size)
+{
+       unsigned long blk_start, blk_end;
+       phys_addr_t blk_paddr;
+       arm_lpae_iopte table = 0;
+       void *cookie = data->iop.cookie;
+       const struct iommu_gather_ops *tlb = data->iop.cfg.tlb;
+
+       blk_start = iova & ~(blk_size - 1);
+       blk_end = blk_start + blk_size;
+       blk_paddr = iopte_to_pfn(*ptep, data) << data->pg_shift;
+
+       for (; blk_start < blk_end; blk_start += size, blk_paddr += size) {
+               arm_lpae_iopte *tablep;
+
+               /* Unmap! */
+               if (blk_start == iova)
+                       continue;
+
+               /* __arm_lpae_map expects a pointer to the start of the table */
+               tablep = &table - ARM_LPAE_LVL_IDX(blk_start, lvl, data);
+               if (__arm_lpae_map(data, blk_start, blk_paddr, size, prot, lvl,
+                                  tablep) < 0) {
+                       if (table) {
+                               /* Free the table we allocated */
+                               tablep = iopte_deref(table, data);
+                               __arm_lpae_free_pgtable(data, lvl + 1, tablep);
+                       }
+                       return 0; /* Bytes unmapped */
+               }
+       }
+
+       *ptep = table;
+       tlb->flush_pgtable(ptep, sizeof(*ptep), cookie);
+       iova &= ~(blk_size - 1);
+       tlb->tlb_add_flush(iova, blk_size, true, cookie);
+       return size;
+}
+
+static int __arm_lpae_unmap(struct arm_lpae_io_pgtable *data,
+                           unsigned long iova, size_t size, int lvl,
+                           arm_lpae_iopte *ptep)
+{
+       arm_lpae_iopte pte;
+       const struct iommu_gather_ops *tlb = data->iop.cfg.tlb;
+       void *cookie = data->iop.cookie;
+       size_t blk_size = ARM_LPAE_BLOCK_SIZE(lvl, data);
+
+       ptep += ARM_LPAE_LVL_IDX(iova, lvl, data);
+       pte = *ptep;
+
+       /* Something went horribly wrong and we ran out of page table */
+       if (WARN_ON(!pte || (lvl == ARM_LPAE_MAX_LEVELS)))
+               return 0;
+
+       /* If the size matches this level, we're in the right place */
+       if (size == blk_size) {
+               *ptep = 0;
+               tlb->flush_pgtable(ptep, sizeof(*ptep), cookie);
+
+               if (!iopte_leaf(pte, lvl)) {
+                       /* Also flush any partial walks */
+                       tlb->tlb_add_flush(iova, size, false, cookie);
+                       tlb->tlb_sync(data->iop.cookie);
+                       ptep = iopte_deref(pte, data);
+                       __arm_lpae_free_pgtable(data, lvl + 1, ptep);
+               } else {
+                       tlb->tlb_add_flush(iova, size, true, cookie);
+               }
+
+               return size;
+       } else if (iopte_leaf(pte, lvl)) {
+               /*
+                * Insert a table at the next level to map the old region,
+                * minus the part we want to unmap
+                */
+               return arm_lpae_split_blk_unmap(data, iova, size,
+                                               iopte_prot(pte), lvl, ptep,
+                                               blk_size);
+       }
+
+       /* Keep on walkin' */
+       ptep = iopte_deref(pte, data);
+       return __arm_lpae_unmap(data, iova, size, lvl + 1, ptep);
+}
+
+static int arm_lpae_unmap(struct io_pgtable_ops *ops, unsigned long iova,
+                         size_t size)
+{
+       size_t unmapped;
+       struct arm_lpae_io_pgtable *data = io_pgtable_ops_to_data(ops);
+       struct io_pgtable *iop = &data->iop;
+       arm_lpae_iopte *ptep = data->pgd;
+       int lvl = ARM_LPAE_START_LVL(data);
+
+       unmapped = __arm_lpae_unmap(data, iova, size, lvl, ptep);
+       if (unmapped)
+               iop->cfg.tlb->tlb_sync(iop->cookie);
+
+       return unmapped;
+}
+
+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);
+       arm_lpae_iopte pte, *ptep = data->pgd;
+       int lvl = ARM_LPAE_START_LVL(data);
+
+       do {
+               /* Valid IOPTE pointer? */
+               if (!ptep)
+                       return 0;
+
+               /* Grab the IOPTE we're interested in */
+               pte = *(ptep + ARM_LPAE_LVL_IDX(iova, lvl, data));
+
+               /* Valid entry? */
+               if (!pte)
+                       return 0;
+
+               /* Leaf entry? */
+               if (iopte_leaf(pte,lvl))
+                       goto found_translation;
+
+               /* Take it to the next level */
+               ptep = iopte_deref(pte, data);
+       } while (++lvl < ARM_LPAE_MAX_LEVELS);
+
+       /* Ran out of page tables to walk */
+       return 0;
+
+found_translation:
+       iova &= ((1 << data->pg_shift) - 1);
+       return ((phys_addr_t)iopte_to_pfn(pte,data) << data->pg_shift) | iova;
+}
+
+static void arm_lpae_restrict_pgsizes(struct io_pgtable_cfg *cfg)
+{
+       unsigned long granule;
+
+       /*
+        * We need to restrict the supported page sizes to match the
+        * translation regime for a particular granule. Aim to match
+        * the CPU page size if possible, otherwise prefer smaller sizes.
+        * While we're at it, restrict the block sizes to match the
+        * chosen granule.
+        */
+       if (cfg->pgsize_bitmap & PAGE_SIZE)
+               granule = PAGE_SIZE;
+       else if (cfg->pgsize_bitmap & ~PAGE_MASK)
+               granule = 1UL << __fls(cfg->pgsize_bitmap & ~PAGE_MASK);
+       else if (cfg->pgsize_bitmap & PAGE_MASK)
+               granule = 1UL << __ffs(cfg->pgsize_bitmap & PAGE_MASK);
+       else
+               granule = 0;
+
+       switch (granule) {
+       case SZ_4K:
+               cfg->pgsize_bitmap &= (SZ_4K | SZ_2M | SZ_1G);
+               break;
+       case SZ_16K:
+               cfg->pgsize_bitmap &= (SZ_16K | SZ_32M);
+               break;
+       case SZ_64K:
+               cfg->pgsize_bitmap &= (SZ_64K | SZ_512M);
+               break;
+       default:
+               cfg->pgsize_bitmap = 0;
+       }
+}
+
+static struct arm_lpae_io_pgtable *
+arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg)
+{
+       unsigned long va_bits, pgd_bits;
+       struct arm_lpae_io_pgtable *data;
+
+       arm_lpae_restrict_pgsizes(cfg);
+
+       if (!(cfg->pgsize_bitmap & (SZ_4K | SZ_16K | SZ_64K)))
+               return NULL;
+
+       if (cfg->ias > ARM_LPAE_MAX_ADDR_BITS)
+               return NULL;
+
+       if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS)
+               return NULL;
+
+       data = kmalloc(sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return NULL;
+
+       data->pg_shift = __ffs(cfg->pgsize_bitmap);
+       data->bits_per_level = data->pg_shift - ilog2(sizeof(arm_lpae_iopte));
+
+       va_bits = cfg->ias - data->pg_shift;
+       data->levels = DIV_ROUND_UP(va_bits, data->bits_per_level);
+
+       /* Calculate the actual size of our pgd (without concatenation) */
+       pgd_bits = va_bits - (data->bits_per_level * (data->levels - 1));
+       data->pgd_size = 1UL << (pgd_bits + ilog2(sizeof(arm_lpae_iopte)));
+
+       data->iop.ops = (struct io_pgtable_ops) {
+               .map            = arm_lpae_map,
+               .unmap          = arm_lpae_unmap,
+               .iova_to_phys   = arm_lpae_iova_to_phys,
+       };
+
+       return data;
+}
+
+static struct io_pgtable *
+arm_64_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
+{
+       u64 reg;
+       struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg);
+
+       if (!data)
+               return NULL;
+
+       /* TCR */
+       reg = (ARM_LPAE_TCR_SH_IS << ARM_LPAE_TCR_SH0_SHIFT) |
+             (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_IRGN0_SHIFT) |
+             (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_ORGN0_SHIFT);
+
+       switch (1 << data->pg_shift) {
+       case SZ_4K:
+               reg |= ARM_LPAE_TCR_TG0_4K;
+               break;
+       case SZ_16K:
+               reg |= ARM_LPAE_TCR_TG0_16K;
+               break;
+       case SZ_64K:
+               reg |= ARM_LPAE_TCR_TG0_64K;
+               break;
+       }
+
+       switch (cfg->oas) {
+       case 32:
+               reg |= (ARM_LPAE_TCR_PS_32_BIT << ARM_LPAE_TCR_IPS_SHIFT);
+               break;
+       case 36:
+               reg |= (ARM_LPAE_TCR_PS_36_BIT << ARM_LPAE_TCR_IPS_SHIFT);
+               break;
+       case 40:
+               reg |= (ARM_LPAE_TCR_PS_40_BIT << ARM_LPAE_TCR_IPS_SHIFT);
+               break;
+       case 42:
+               reg |= (ARM_LPAE_TCR_PS_42_BIT << ARM_LPAE_TCR_IPS_SHIFT);
+               break;
+       case 44:
+               reg |= (ARM_LPAE_TCR_PS_44_BIT << ARM_LPAE_TCR_IPS_SHIFT);
+               break;
+       case 48:
+               reg |= (ARM_LPAE_TCR_PS_48_BIT << ARM_LPAE_TCR_IPS_SHIFT);
+               break;
+       default:
+               goto out_free_data;
+       }
+
+       reg |= (64ULL - cfg->ias) << ARM_LPAE_TCR_T0SZ_SHIFT;
+       cfg->arm_lpae_s1_cfg.tcr = reg;
+
+       /* MAIRs */
+       reg = (ARM_LPAE_MAIR_ATTR_NC
+              << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_NC)) |
+             (ARM_LPAE_MAIR_ATTR_WBRWA
+              << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_CACHE)) |
+             (ARM_LPAE_MAIR_ATTR_DEVICE
+              << ARM_LPAE_MAIR_ATTR_SHIFT(ARM_LPAE_MAIR_ATTR_IDX_DEV));
+
+       cfg->arm_lpae_s1_cfg.mair[0] = reg;
+       cfg->arm_lpae_s1_cfg.mair[1] = 0;
+
+       /* Looking good; allocate a pgd */
+       data->pgd = alloc_pages_exact(data->pgd_size, GFP_KERNEL | __GFP_ZERO);
+       if (!data->pgd)
+               goto out_free_data;
+
+       cfg->tlb->flush_pgtable(data->pgd, data->pgd_size, cookie);
+
+       /* TTBRs */
+       cfg->arm_lpae_s1_cfg.ttbr[0] = virt_to_phys(data->pgd);
+       cfg->arm_lpae_s1_cfg.ttbr[1] = 0;
+       return &data->iop;
+
+out_free_data:
+       kfree(data);
+       return NULL;
+}
+
+static struct io_pgtable *
+arm_64_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
+{
+       u64 reg, sl;
+       struct arm_lpae_io_pgtable *data = arm_lpae_alloc_pgtable(cfg);
+
+       if (!data)
+               return NULL;
+
+       /*
+        * Concatenate PGDs at level 1 if possible in order to reduce
+        * the depth of the stage-2 walk.
+        */
+       if (data->levels == ARM_LPAE_MAX_LEVELS) {
+               unsigned long pgd_pages;
+
+               pgd_pages = data->pgd_size >> ilog2(sizeof(arm_lpae_iopte));
+               if (pgd_pages <= ARM_LPAE_S2_MAX_CONCAT_PAGES) {
+                       data->pgd_size = pgd_pages << data->pg_shift;
+                       data->levels--;
+               }
+       }
+
+       /* VTCR */
+       reg = ARM_64_LPAE_S2_TCR_RES1 |
+            (ARM_LPAE_TCR_SH_IS << ARM_LPAE_TCR_SH0_SHIFT) |
+            (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_IRGN0_SHIFT) |
+            (ARM_LPAE_TCR_RGN_WBWA << ARM_LPAE_TCR_ORGN0_SHIFT);
+
+       sl = ARM_LPAE_START_LVL(data);
+
+       switch (1 << data->pg_shift) {
+       case SZ_4K:
+               reg |= ARM_LPAE_TCR_TG0_4K;
+               sl++; /* SL0 format is different for 4K granule size */
+               break;
+       case SZ_16K:
+               reg |= ARM_LPAE_TCR_TG0_16K;
+               break;
+       case SZ_64K:
+               reg |= ARM_LPAE_TCR_TG0_64K;
+               break;
+       }
+
+       switch (cfg->oas) {
+       case 32:
+               reg |= (ARM_LPAE_TCR_PS_32_BIT << ARM_LPAE_TCR_PS_SHIFT);
+               break;
+       case 36:
+               reg |= (ARM_LPAE_TCR_PS_36_BIT << ARM_LPAE_TCR_PS_SHIFT);
+               break;
+       case 40:
+               reg |= (ARM_LPAE_TCR_PS_40_BIT << ARM_LPAE_TCR_PS_SHIFT);
+               break;
+       case 42:
+               reg |= (ARM_LPAE_TCR_PS_42_BIT << ARM_LPAE_TCR_PS_SHIFT);
+               break;
+       case 44:
+               reg |= (ARM_LPAE_TCR_PS_44_BIT << ARM_LPAE_TCR_PS_SHIFT);
+               break;
+       case 48:
+               reg |= (ARM_LPAE_TCR_PS_48_BIT << ARM_LPAE_TCR_PS_SHIFT);
+               break;
+       default:
+               goto out_free_data;
+       }
+
+       reg |= (64ULL - cfg->ias) << ARM_LPAE_TCR_T0SZ_SHIFT;
+       reg |= (~sl & ARM_LPAE_TCR_SL0_MASK) << ARM_LPAE_TCR_SL0_SHIFT;
+       cfg->arm_lpae_s2_cfg.vtcr = reg;
+
+       /* Allocate pgd pages */
+       data->pgd = alloc_pages_exact(data->pgd_size, GFP_KERNEL | __GFP_ZERO);
+       if (!data->pgd)
+               goto out_free_data;
+
+       cfg->tlb->flush_pgtable(data->pgd, data->pgd_size, cookie);
+
+       /* VTTBR */
+       cfg->arm_lpae_s2_cfg.vttbr = virt_to_phys(data->pgd);
+       return &data->iop;
+
+out_free_data:
+       kfree(data);
+       return NULL;
+}
+
+static struct io_pgtable *
+arm_32_lpae_alloc_pgtable_s1(struct io_pgtable_cfg *cfg, void *cookie)
+{
+       struct io_pgtable *iop;
+
+       if (cfg->ias > 32 || cfg->oas > 40)
+               return NULL;
+
+       cfg->pgsize_bitmap &= (SZ_4K | SZ_2M | SZ_1G);
+       iop = arm_64_lpae_alloc_pgtable_s1(cfg, cookie);
+       if (iop) {
+               cfg->arm_lpae_s1_cfg.tcr |= ARM_32_LPAE_TCR_EAE;
+               cfg->arm_lpae_s1_cfg.tcr &= 0xffffffff;
+       }
+
+       return iop;
+}
+
+static struct io_pgtable *
+arm_32_lpae_alloc_pgtable_s2(struct io_pgtable_cfg *cfg, void *cookie)
+{
+       struct io_pgtable *iop;
+
+       if (cfg->ias > 40 || cfg->oas > 40)
+               return NULL;
+
+       cfg->pgsize_bitmap &= (SZ_4K | SZ_2M | SZ_1G);
+       iop = arm_64_lpae_alloc_pgtable_s2(cfg, cookie);
+       if (iop)
+               cfg->arm_lpae_s2_cfg.vtcr &= 0xffffffff;
+
+       return iop;
+}
+
+struct io_pgtable_init_fns io_pgtable_arm_64_lpae_s1_init_fns = {
+       .alloc  = arm_64_lpae_alloc_pgtable_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,
+};
+
+struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s1_init_fns = {
+       .alloc  = arm_32_lpae_alloc_pgtable_s1,
+       .free   = arm_lpae_free_pgtable,
+};
+
+struct io_pgtable_init_fns io_pgtable_arm_32_lpae_s2_init_fns = {
+       .alloc  = arm_32_lpae_alloc_pgtable_s2,
+       .free   = arm_lpae_free_pgtable,
+};
index f664a1ca49cf8f126ab137eaf2a813250475cb45..6436fe24bc2f6fdc0273d6017056a24f964b640e 100644 (file)
 
 #include "io-pgtable.h"
 
+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;
+
 static const struct io_pgtable_init_fns *
 io_pgtable_init_table[IO_PGTABLE_NUM_FMTS] =
 {
+#ifdef CONFIG_IOMMU_IO_PGTABLE_LPAE
+       [ARM_32_LPAE_S1] = &io_pgtable_arm_32_lpae_s1_init_fns,
+       [ARM_32_LPAE_S2] = &io_pgtable_arm_32_lpae_s2_init_fns,
+       [ARM_64_LPAE_S1] = &io_pgtable_arm_64_lpae_s1_init_fns,
+       [ARM_64_LPAE_S2] = &io_pgtable_arm_64_lpae_s2_init_fns,
+#endif
 };
 
 struct io_pgtable_ops *alloc_io_pgtable_ops(enum io_pgtable_fmt fmt,
index fdd792c3769825528b6c443c3e3a9440b7b6beb0..05c4e593a25f68229111dedebdfb71fa530c81c1 100644 (file)
@@ -5,6 +5,10 @@
  * Public API for use by IOMMU drivers
  */
 enum io_pgtable_fmt {
+       ARM_32_LPAE_S1,
+       ARM_32_LPAE_S2,
+       ARM_64_LPAE_S1,
+       ARM_64_LPAE_S2,
        IO_PGTABLE_NUM_FMTS,
 };
 
@@ -47,6 +51,16 @@ struct io_pgtable_cfg {
 
        /* Low-level data specific to the table format */
        union {
+               struct {
+                       u64     ttbr[2];
+                       u64     tcr;
+                       u64     mair[2];
+               } arm_lpae_s1_cfg;
+
+               struct {
+                       u64     vttbr;
+                       u64     vtcr;
+               } arm_lpae_s2_cfg;
        };
 };