arch/arm/include/asm/pgtable-3level.h

   1 /*
   2  * arch/arm/include/asm/pgtable-3level.h
   3  *
   4  * Copyright (C) 2011 ARM Ltd.
   5  * Author: Catalin Marinas <catalin.marinas@arm.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  19  */
  20 #ifndef _ASM_PGTABLE_3LEVEL_H
  21 #define _ASM_PGTABLE_3LEVEL_H
  22
  23 /*
  24  * With LPAE, there are 3 levels of page tables. Each level has 512 entries of
  25  * 8 bytes each, occupying a 4K page. The first level table covers a range of
  26  * 512GB, each entry representing 1GB. Since we are limited to 4GB input
  27  * address range, only 4 entries in the PGD are used.
  28  *
  29  * There are enough spare bits in a page table entry for the kernel specific
  30  * state.
  31  */
  32 #define PTRS_PER_PTE            512
  33 #define PTRS_PER_PMD            512
  34 #define PTRS_PER_PGD            4
  35
  36 #define PTE_HWTABLE_PTRS        (0)
  37 #define PTE_HWTABLE_OFF         (0)
  38 #define PTE_HWTABLE_SIZE        (PTRS_PER_PTE * sizeof(u64))
  39
  40 /*
  41  * PGDIR_SHIFT determines the size a top-level page table entry can map.
  42  */
  43 #define PGDIR_SHIFT             30
  44
  45 /*
  46  * PMD_SHIFT determines the size a middle-level page table entry can map.
  47  */
  48 #define PMD_SHIFT               21
  49
  50 #define PMD_SIZE                (1UL << PMD_SHIFT)
  51 #define PMD_MASK                (~((1 << PMD_SHIFT) - 1))
  52 #define PGDIR_SIZE              (1UL << PGDIR_SHIFT)
  53 #define PGDIR_MASK              (~((1 << PGDIR_SHIFT) - 1))
  54
  55 /*
  56  * section address mask and size definitions.
  57  */
  58 #define SECTION_SHIFT           21
  59 #define SECTION_SIZE            (1UL << SECTION_SHIFT)
  60 #define SECTION_MASK            (~((1 << SECTION_SHIFT) - 1))
  61
  62 #define USER_PTRS_PER_PGD       (PAGE_OFFSET / PGDIR_SIZE)
  63
  64 /*
  65  * Hugetlb definitions.
  66  */
  67 #define HPAGE_SHIFT             PMD_SHIFT
  68 #define HPAGE_SIZE              (_AC(1, UL) << HPAGE_SHIFT)
  69 #define HPAGE_MASK              (~(HPAGE_SIZE - 1))
  70 #define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
  71
  72 /*
  73  * "Linux" PTE definitions for LPAE.
  74  *
  75  * These bits overlap with the hardware bits but the naming is preserved for
  76  * consistency with the classic page table format.
  77  */
  78 #define L_PTE_VALID             (_AT(pteval_t, 1) << 0)         /* Valid */
  79 #define L_PTE_PRESENT           (_AT(pteval_t, 3) << 0)         /* Present */
  80 #define L_PTE_FILE              (_AT(pteval_t, 1) << 2)         /* only when !PRESENT */
  81 #define L_PTE_USER              (_AT(pteval_t, 1) << 6)         /* AP[1] */
  82 #define L_PTE_RDONLY            (_AT(pteval_t, 1) << 7)         /* AP[2] */
  83 #define L_PTE_SHARED            (_AT(pteval_t, 3) << 8)         /* SH[1:0], inner shareable */
  84 #define L_PTE_YOUNG             (_AT(pteval_t, 1) << 10)        /* AF */
  85 #define L_PTE_XN                (_AT(pteval_t, 1) << 54)        /* XN */
  86 #define L_PTE_DIRTY             (_AT(pteval_t, 1) << 55)        /* unused */
  87 #define L_PTE_SPECIAL           (_AT(pteval_t, 1) << 56)        /* unused */
  88 #define L_PTE_NONE              (_AT(pteval_t, 1) << 57)        /* PROT_NONE */
  89
  90 #define PMD_SECT_VALID          (_AT(pmdval_t, 1) << 0)
  91 #define PMD_SECT_DIRTY          (_AT(pmdval_t, 1) << 55)
  92 #define PMD_SECT_SPLITTING      (_AT(pmdval_t, 1) << 56)
  93 #define PMD_SECT_NONE           (_AT(pmdval_t, 1) << 57)
  94
  95 /*
  96  * To be used in assembly code with the upper page attributes.
  97  */
  98 #define L_PTE_XN_HIGH           (1 << (54 - 32))
  99 #define L_PTE_DIRTY_HIGH        (1 << (55 - 32))
 100
 101 /*
 102  * AttrIndx[2:0] encoding (mapping attributes defined in the MAIR* registers).
 103  */
 104 #define L_PTE_MT_UNCACHED       (_AT(pteval_t, 0) << 2) /* strongly ordered */
 105 #define L_PTE_MT_BUFFERABLE     (_AT(pteval_t, 1) << 2) /* normal non-cacheable */
 106 #define L_PTE_MT_WRITETHROUGH   (_AT(pteval_t, 2) << 2) /* normal inner write-through */
 107 #define L_PTE_MT_WRITEBACK      (_AT(pteval_t, 3) << 2) /* normal inner write-back */
 108 #define L_PTE_MT_WRITEALLOC     (_AT(pteval_t, 7) << 2) /* normal inner write-alloc */
 109 #define L_PTE_MT_DEV_SHARED     (_AT(pteval_t, 4) << 2) /* device */
 110 #define L_PTE_MT_DEV_NONSHARED  (_AT(pteval_t, 4) << 2) /* device */
 111 #define L_PTE_MT_DEV_WC         (_AT(pteval_t, 1) << 2) /* normal non-cacheable */
 112 #define L_PTE_MT_DEV_CACHED     (_AT(pteval_t, 3) << 2) /* normal inner write-back */
 113 #define L_PTE_MT_MASK           (_AT(pteval_t, 7) << 2)
 114
 115 /*
 116  * Software PGD flags.
 117  */
 118 #define L_PGD_SWAPPER           (_AT(pgdval_t, 1) << 55)        /* swapper_pg_dir entry */
 119
 120 /*
 121  * 2nd stage PTE definitions for LPAE.
 122  */
 123 #define L_PTE_S2_MT_UNCACHED     (_AT(pteval_t, 0x5) << 2) /* MemAttr[3:0] */
 124 #define L_PTE_S2_MT_WRITETHROUGH (_AT(pteval_t, 0xa) << 2) /* MemAttr[3:0] */
 125 #define L_PTE_S2_MT_WRITEBACK    (_AT(pteval_t, 0xf) << 2) /* MemAttr[3:0] */
 126 #define L_PTE_S2_RDONLY          (_AT(pteval_t, 1) << 6)   /* HAP[1]   */
 127 #define L_PTE_S2_RDWR            (_AT(pteval_t, 3) << 6)   /* HAP[2:1] */
 128
 129 /*
 130  * Hyp-mode PL2 PTE definitions for LPAE.
 131  */
 132 #define L_PTE_HYP               L_PTE_USER
 133
 134 #ifndef __ASSEMBLY__
 135
 136 #define pud_none(pud)           (!pud_val(pud))
 137 #define pud_bad(pud)            (!(pud_val(pud) & 2))
 138 #define pud_present(pud)        (pud_val(pud))
 139 #define pmd_table(pmd)          ((pmd_val(pmd) & PMD_TYPE_MASK) == \
 140                                                  PMD_TYPE_TABLE)
 141 #define pmd_sect(pmd)           ((pmd_val(pmd) & PMD_TYPE_MASK) == \
 142                                                  PMD_TYPE_SECT)
 143
 144 #define pud_clear(pudp)                 \
 145         do {                            \
 146                 *pudp = __pud(0);       \
 147                 clean_pmd_entry(pudp);  \
 148         } while (0)
 149
 150 #define set_pud(pudp, pud)              \
 151         do {                            \
 152                 *pudp = pud;            \
 153                 flush_pmd_entry(pudp);  \
 154         } while (0)
 155
 156 static inline pmd_t *pud_page_vaddr(pud_t pud)
 157 {
 158         return __va(pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK);
 159 }
 160
 161 /* Find an entry in the second-level page table.. */
 162 #define pmd_index(addr)         (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
 163 static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
 164 {
 165         return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
 166 }
 167
 168 #define pmd_bad(pmd)            (!(pmd_val(pmd) & 2))
 169
 170 #define copy_pmd(pmdpd,pmdps)           \
 171         do {                            \
 172                 *pmdpd = *pmdps;        \
 173                 flush_pmd_entry(pmdpd); \
 174         } while (0)
 175
 176 #define pmd_clear(pmdp)                 \
 177         do {                            \
 178                 *pmdp = __pmd(0);       \
 179                 clean_pmd_entry(pmdp);  \
 180         } while (0)
 181
 182 /*
 183  * For 3 levels of paging the PTE_EXT_NG bit will be set for user address ptes
 184  * that are written to a page table but not for ptes created with mk_pte.
 185  *
 186  * In hugetlb_no_page, a new huge pte (new_pte) is generated and passed to
 187  * hugetlb_cow, where it is compared with an entry in a page table.
 188  * This comparison test fails erroneously leading ultimately to a memory leak.
 189  *
 190  * To correct this behaviour, we mask off PTE_EXT_NG for any pte that is
 191  * present before running the comparison.
 192  */
 193 #define __HAVE_ARCH_PTE_SAME
 194 #define pte_same(pte_a,pte_b)   ((pte_present(pte_a) ? pte_val(pte_a) & ~PTE_EXT_NG     \
 195                                         : pte_val(pte_a))                               \
 196                                 == (pte_present(pte_b) ? pte_val(pte_b) & ~PTE_EXT_NG   \
 197                                         : pte_val(pte_b)))
 198
 199 #define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,__pte(pte_val(pte)|(ext)))
 200
 201 #define pte_huge(pte)           (pte_val(pte) && !(pte_val(pte) & PTE_TABLE_BIT))
 202 #define pte_mkhuge(pte)         (__pte(pte_val(pte) & ~PTE_TABLE_BIT))
 203
 204 #define pmd_young(pmd)          (pmd_val(pmd) & PMD_SECT_AF)
 205
 206 #define __HAVE_ARCH_PMD_WRITE
 207 #define pmd_write(pmd)          (!(pmd_val(pmd) & PMD_SECT_RDONLY))
 208
 209 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 210 #define pmd_trans_huge(pmd)     (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
 211 #define pmd_trans_splitting(pmd) (pmd_val(pmd) & PMD_SECT_SPLITTING)
 212 #endif
 213
 214 #define PMD_BIT_FUNC(fn,op) \
 215 static inline pmd_t pmd_##fn(pmd_t pmd) { pmd_val(pmd) op; return pmd; }
 216
 217 PMD_BIT_FUNC(wrprotect, |= PMD_SECT_RDONLY);
 218 PMD_BIT_FUNC(mkold,     &= ~PMD_SECT_AF);
 219 PMD_BIT_FUNC(mksplitting, |= PMD_SECT_SPLITTING);
 220 PMD_BIT_FUNC(mkwrite,   &= ~PMD_SECT_RDONLY);
 221 PMD_BIT_FUNC(mkdirty,   |= PMD_SECT_DIRTY);
 222 PMD_BIT_FUNC(mkyoung,   |= PMD_SECT_AF);
 223
 224 #define pmd_mkhuge(pmd)         (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
 225
 226 #define pmd_pfn(pmd)            (((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
 227 #define pfn_pmd(pfn,prot)       (__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
 228 #define mk_pmd(page,prot)       pfn_pmd(page_to_pfn(page),prot)
 229
 230 /* represent a notpresent pmd by zero, this is used by pmdp_invalidate */
 231 #define pmd_mknotpresent(pmd)   (__pmd(0))
 232
 233 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 234 {
 235         const pmdval_t mask = PMD_SECT_USER | PMD_SECT_XN | PMD_SECT_RDONLY |
 236                                 PMD_SECT_VALID | PMD_SECT_NONE;
 237         pmd_val(pmd) = (pmd_val(pmd) & ~mask) | (pgprot_val(newprot) & mask);
 238         return pmd;
 239 }
 240
 241 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr,
 242                               pmd_t *pmdp, pmd_t pmd)
 243 {
 244         BUG_ON(addr >= TASK_SIZE);
 245
 246         /* create a faulting entry if PROT_NONE protected */
 247         if (pmd_val(pmd) & PMD_SECT_NONE)
 248                 pmd_val(pmd) &= ~PMD_SECT_VALID;
 249
 250         *pmdp = __pmd(pmd_val(pmd) | PMD_SECT_nG);
 251         flush_pmd_entry(pmdp);
 252 }
 253
 254 static inline int has_transparent_hugepage(void)
 255 {
 256         return 1;
 257 }
 258
 259 #endif /* __ASSEMBLY__ */
 260
 261 #endif /* _ASM_PGTABLE_3LEVEL_H */