File: /usr/src/linux/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 */
186