arch/powerpc/include/asm/pgtable-64k.h

   1 #ifndef _ASM_POWERPC_PGTABLE_64K_H
   2 #define _ASM_POWERPC_PGTABLE_64K_H
   3
   4 #include <asm-generic/pgtable-nopud.h>
   5
   6
   7 #define PTE_INDEX_SIZE  12
   8 #define PMD_INDEX_SIZE  12
   9 #define PUD_INDEX_SIZE  0
  10 #define PGD_INDEX_SIZE  4
  11
  12 #ifndef __ASSEMBLY__
  13 #define PTE_TABLE_SIZE  (sizeof(real_pte_t) << PTE_INDEX_SIZE)
  14 #define PMD_TABLE_SIZE  (sizeof(pmd_t) << PMD_INDEX_SIZE)
  15 #define PGD_TABLE_SIZE  (sizeof(pgd_t) << PGD_INDEX_SIZE)
  16
  17 #define PTRS_PER_PTE    (1 << PTE_INDEX_SIZE)
  18 #define PTRS_PER_PMD    (1 << PMD_INDEX_SIZE)
  19 #define PTRS_PER_PGD    (1 << PGD_INDEX_SIZE)
  20
  21 #ifdef CONFIG_PPC_SUBPAGE_PROT
  22 /*
  23  * For the sub-page protection option, we extend the PGD with one of
  24  * these.  Basically we have a 3-level tree, with the top level being
  25  * the protptrs array.  To optimize speed and memory consumption when
  26  * only addresses < 4GB are being protected, pointers to the first
  27  * four pages of sub-page protection words are stored in the low_prot
  28  * array.
  29  * Each page of sub-page protection words protects 1GB (4 bytes
  30  * protects 64k).  For the 3-level tree, each page of pointers then
  31  * protects 8TB.
  32  */
  33 struct subpage_prot_table {
  34         unsigned long maxaddr;  /* only addresses < this are protected */
  35         unsigned int **protptrs[2];
  36         unsigned int *low_prot[4];
  37 };
  38
  39 #undef PGD_TABLE_SIZE
  40 #define PGD_TABLE_SIZE          ((sizeof(pgd_t) << PGD_INDEX_SIZE) + \
  41                                  sizeof(struct subpage_prot_table))
  42
  43 #define SBP_L1_BITS             (PAGE_SHIFT - 2)
  44 #define SBP_L2_BITS             (PAGE_SHIFT - 3)
  45 #define SBP_L1_COUNT            (1 << SBP_L1_BITS)
  46 #define SBP_L2_COUNT            (1 << SBP_L2_BITS)
  47 #define SBP_L2_SHIFT            (PAGE_SHIFT + SBP_L1_BITS)
  48 #define SBP_L3_SHIFT            (SBP_L2_SHIFT + SBP_L2_BITS)
  49
  50 extern void subpage_prot_free(pgd_t *pgd);
  51
  52 static inline struct subpage_prot_table *pgd_subpage_prot(pgd_t *pgd)
  53 {
  54         return (struct subpage_prot_table *)(pgd + PTRS_PER_PGD);
  55 }
  56 #endif /* CONFIG_PPC_SUBPAGE_PROT */
  57 #endif  /* __ASSEMBLY__ */
  58
  59 /* With 4k base page size, hugepage PTEs go at the PMD level */
  60 #define MIN_HUGEPTE_SHIFT       PAGE_SHIFT
  61
  62 /* PMD_SHIFT determines what a second-level page table entry can map */
  63 #define PMD_SHIFT       (PAGE_SHIFT + PTE_INDEX_SIZE)
  64 #define PMD_SIZE        (1UL << PMD_SHIFT)
  65 #define PMD_MASK        (~(PMD_SIZE-1))
  66
  67 /* PGDIR_SHIFT determines what a third-level page table entry can map */
  68 #define PGDIR_SHIFT     (PMD_SHIFT + PMD_INDEX_SIZE)
  69 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  70 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
  71
  72 /* Additional PTE bits (don't change without checking asm in hash_low.S) */
  73 #define __HAVE_ARCH_PTE_SPECIAL
  74 #define _PAGE_SPECIAL   0x00000400 /* software: special page */
  75 #define _PAGE_HPTE_SUB  0x0ffff000 /* combo only: sub pages HPTE bits */
  76 #define _PAGE_HPTE_SUB0 0x08000000 /* combo only: first sub page */
  77 #define _PAGE_COMBO     0x10000000 /* this is a combo 4k page */
  78 #define _PAGE_4K_PFN    0x20000000 /* PFN is for a single 4k page */
  79
  80 /* For 64K page, we don't have a separate _PAGE_HASHPTE bit. Instead,
  81  * we set that to be the whole sub-bits mask. The C code will only
  82  * test this, so a multi-bit mask will work. For combo pages, this
  83  * is equivalent as effectively, the old _PAGE_HASHPTE was an OR of
  84  * all the sub bits. For real 64k pages, we now have the assembly set
  85  * _PAGE_HPTE_SUB0 in addition to setting the HIDX bits which overlap
  86  * that mask. This is fine as long as the HIDX bits are never set on
  87  * a PTE that isn't hashed, which is the case today.
  88  *
  89  * A little nit is for the huge page C code, which does the hashing
  90  * in C, we need to provide which bit to use.
  91  */
  92 #define _PAGE_HASHPTE   _PAGE_HPTE_SUB
  93
  94 /* Note the full page bits must be in the same location as for normal
  95  * 4k pages as the same asssembly will be used to insert 64K pages
  96  * wether the kernel has CONFIG_PPC_64K_PAGES or not
  97  */
  98 #define _PAGE_F_SECOND  0x00008000 /* full page: hidx bits */
  99 #define _PAGE_F_GIX     0x00007000 /* full page: hidx bits */
 100
 101 /* PTE flags to conserve for HPTE identification */
 102 #define _PAGE_HPTEFLAGS (_PAGE_BUSY | _PAGE_HASHPTE | _PAGE_COMBO)
 103
 104 /* Shift to put page number into pte.
 105  *
 106  * That gives us a max RPN of 34 bits, which means a max of 50 bits
 107  * of addressable physical space, or 46 bits for the special 4k PFNs.
 108  */
 109 #define PTE_RPN_SHIFT   (30)
 110 #define PTE_RPN_MAX     (1UL << (64 - PTE_RPN_SHIFT))
 111 #define PTE_RPN_MASK    (~((1UL<<PTE_RPN_SHIFT)-1))
 112
 113 /* _PAGE_CHG_MASK masks of bits that are to be preserved accross
 114  * pgprot changes
 115  */
 116 #define _PAGE_CHG_MASK  (PTE_RPN_MASK | _PAGE_HPTEFLAGS | _PAGE_DIRTY | \
 117                          _PAGE_ACCESSED | _PAGE_SPECIAL)
 118
 119 /* Bits to mask out from a PMD to get to the PTE page */
 120 #define PMD_MASKED_BITS         0x1ff
 121 /* Bits to mask out from a PGD/PUD to get to the PMD page */
 122 #define PUD_MASKED_BITS         0x1ff
 123
 124 /* Manipulate "rpte" values */
 125 #define __real_pte(e,p)         ((real_pte_t) { \
 126         (e), pte_val(*((p) + PTRS_PER_PTE)) })
 127 #define __rpte_to_hidx(r,index) ((pte_val((r).pte) & _PAGE_COMBO) ? \
 128         (((r).hidx >> ((index)<<2)) & 0xf) : ((pte_val((r).pte) >> 12) & 0xf))
 129 #define __rpte_to_pte(r)        ((r).pte)
 130 #define __rpte_sub_valid(rpte, index) \
 131         (pte_val(rpte.pte) & (_PAGE_HPTE_SUB0 >> (index)))
 132
 133
 134 /* Trick: we set __end to va + 64k, which happens works for
 135  * a 16M page as well as we want only one iteration
 136  */
 137 #define pte_iterate_hashed_subpages(rpte, psize, va, index, shift)          \
 138         do {                                                                \
 139                 unsigned long __end = va + PAGE_SIZE;                       \
 140                 unsigned __split = (psize == MMU_PAGE_4K ||                 \
 141                                     psize == MMU_PAGE_64K_AP);              \
 142                 shift = mmu_psize_defs[psize].shift;                        \
 143                 for (index = 0; va < __end; index++, va += (1L << shift)) { \
 144                         if (!__split || __rpte_sub_valid(rpte, index)) do { \
 145
 146 #define pte_iterate_hashed_end() } while(0); } } while(0)
 147
 148 #define pte_pagesize_index(mm, addr, pte)       \
 149         (((pte) & _PAGE_COMBO)? MMU_PAGE_4K: MMU_PAGE_64K)
 150
 151 #define remap_4k_pfn(vma, addr, pfn, prot)                              \
 152         remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE,                \
 153                         __pgprot(pgprot_val((prot)) | _PAGE_4K_PFN))
 154
 155 #endif /* _ASM_POWERPC_PGTABLE_64K_H */