include/asm-m68k/pgtable.h

   1 #ifndef _M68K_PGTABLE_H
   2 #define _M68K_PGTABLE_H
   3
   4 #include <linux/config.h>
   5 #include <asm/setup.h>
   6
   7 #ifndef __ASSEMBLY__
   8 #include <asm/processor.h>
   9 #include <linux/threads.h>
  10
  11 /*
  12  * This file contains the functions and defines necessary to modify and use
  13  * the m68k page table tree.
  14  */
  15
  16 #include <asm/virtconvert.h>
  17
  18 /* Certain architectures need to do special things when pte's
  19  * within a page table are directly modified.  Thus, the following
  20  * hook is made available.
  21  */
  22 #define set_pte(pteptr, pteval)                                 \
  23         do{                                                     \
  24                 *(pteptr) = (pteval);                           \
  25         } while(0)
  26
  27
  28 /* PMD_SHIFT determines the size of the area a second-level page table can map */
  29 #ifdef CONFIG_SUN3
  30 #define PMD_SHIFT       17
  31 #else
  32 #define PMD_SHIFT       22
  33 #endif
  34 #define PMD_SIZE        (1UL << PMD_SHIFT)
  35 #define PMD_MASK        (~(PMD_SIZE-1))
  36
  37 /* PGDIR_SHIFT determines what a third-level page table entry can map */
  38 #ifdef CONFIG_SUN3
  39 #define PGDIR_SHIFT     17
  40 #else
  41 #define PGDIR_SHIFT     25
  42 #endif
  43 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  44 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
  45
  46 /*
  47  * entries per page directory level: the m68k is configured as three-level,
  48  * so we do have PMD level physically.
  49  */
  50 #ifdef CONFIG_SUN3
  51 #define PTRS_PER_PTE   16
  52 #define PTRS_PER_PMD   1
  53 #define PTRS_PER_PGD   2048
  54 #else
  55 #define PTRS_PER_PTE    1024
  56 #define PTRS_PER_PMD    8
  57 #define PTRS_PER_PGD    128
  58 #endif
  59 #define USER_PTRS_PER_PGD       (TASK_SIZE/PGDIR_SIZE)
  60 #define FIRST_USER_PGD_NR       0
  61
  62 /* Virtual address region for use by kernel_map() */
  63 #ifdef CONFIG_SUN3
  64 #define KMAP_START     0x0DC00000
  65 #define KMAP_END       0x0E000000
  66 #else
  67 #define KMAP_START      0xd0000000
  68 #define KMAP_END        0xf0000000
  69 #endif
  70
  71 #ifndef CONFIG_SUN3
  72 /* Just any arbitrary offset to the start of the vmalloc VM area: the
  73  * current 8MB value just means that there will be a 8MB "hole" after the
  74  * physical memory until the kernel virtual memory starts.  That means that
  75  * any out-of-bounds memory accesses will hopefully be caught.
  76  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  77  * area for the same reason. ;)
  78  */
  79 #define VMALLOC_OFFSET  (8*1024*1024)
  80 #define VMALLOC_START (((unsigned long) high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
  81 #define VMALLOC_VMADDR(x) ((unsigned long)(x))
  82 #define VMALLOC_END KMAP_START
  83 #else
  84 extern unsigned long vmalloc_end;
  85 #define VMALLOC_START 0x0f800000
  86 #define VMALLOC_VMADDR(x) ((unsigned long)(x))
  87 #define VMALLOC_END vmalloc_end
  88 #endif /* CONFIG_SUN3 */
  89
  90 /* zero page used for uninitialized stuff */
  91 extern unsigned long empty_zero_page;
  92
  93 /*
  94  * BAD_PAGETABLE is used when we need a bogus page-table, while
  95  * BAD_PAGE is used for a bogus page.
  96  *
  97  * ZERO_PAGE is a global shared page that is always zero: used
  98  * for zero-mapped memory areas etc..
  99  */
 100 extern pte_t __bad_page(void);
 101 extern pte_t * __bad_pagetable(void);
 102
 103 #define BAD_PAGETABLE __bad_pagetable()
 104 #define BAD_PAGE __bad_page()
 105 #define ZERO_PAGE(vaddr)        (virt_to_page(empty_zero_page))
 106
 107 /* number of bits that fit into a memory pointer */
 108 #define BITS_PER_PTR                    (8*sizeof(unsigned long))
 109
 110 /* to align the pointer to a pointer address */
 111 #define PTR_MASK                        (~(sizeof(void*)-1))
 112
 113 /* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
 114 /* 64-bit machines, beware!  SRB. */
 115 #define SIZEOF_PTR_LOG2                        2
 116
 117 /*
 118  * Check if the addr/len goes up to the end of a physical
 119  * memory chunk.  Used for DMA functions.
 120  */
 121 #ifdef CONFIG_SINGLE_MEMORY_CHUNK
 122 /*
 123  * It makes no sense to consider whether we cross a memory boundary if
 124  * we support just one physical chunk of memory.
 125  */
 126 extern inline int mm_end_of_chunk (unsigned long addr, int len)
 127 {
 128         return 0;
 129 }
 130 #else
 131 int mm_end_of_chunk (unsigned long addr, int len);
 132 #endif
 133
 134 extern void kernel_set_cachemode(void *addr, unsigned long size, int cmode);
 135
 136 /*
 137  * The m68k doesn't have any external MMU info: the kernel page
 138  * tables contain all the necessary information.  The Sun3 does, but
 139  * they are updated on demand.
 140  */
 141 extern inline void update_mmu_cache(struct vm_area_struct * vma,
 142         unsigned long address, pte_t pte)
 143 {
 144 }
 145
 146 #ifdef CONFIG_SUN3
 147 /* Macros to (de)construct the fake PTEs representing swap pages. */
 148 #define SWP_TYPE(x)                ((x).val & 0x7F)
 149 #define SWP_OFFSET(x)      (((x).val) >> 7)
 150 #define SWP_ENTRY(type,offset) ((swp_entry_t) { ((type) | ((offset) << 7)) })
 151 #define pte_to_swp_entry(pte)           ((swp_entry_t) { pte_val(pte) })
 152 #define swp_entry_to_pte(x)             ((pte_t) { (x).val })
 153
 154 #else
 155
 156 /* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */
 157 #define SWP_TYPE(x)                     (((x).val >> 1) & 0xff)
 158 #define SWP_OFFSET(x)                   ((x).val >> 10)
 159 #define SWP_ENTRY(type, offset)         ((swp_entry_t) { ((type) << 1) | ((offset) << 10) })
 160 #define pte_to_swp_entry(pte)           ((swp_entry_t) { pte_val(pte) })
 161 #define swp_entry_to_pte(x)             ((pte_t) { (x).val })
 162
 163 #endif CONFIG_SUN3
 164
 165 #endif /* !__ASSEMBLY__ */
 166
 167 /* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
 168 #define PageSkip(page)          (0)
 169 #define kern_addr_valid(addr)   (1)
 170
 171 #define io_remap_page_range remap_page_range
 172
 173 /* MMU-specific headers */
 174
 175 #ifdef CONFIG_SUN3
 176 #include <asm/sun3_pgtable.h>
 177 #else
 178 #include <asm/motorola_pgtable.h>
 179 #endif
 180
 181 #ifndef __ASSEMBLY__
 182 #include <asm-generic/pgtable.h>
 183 #endif /* !__ASSEMBLY__ */
 184
 185 #endif /* _M68K_PGTABLE_H */