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1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
7 * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
8 */
9#ifndef _ASM_PGTABLE_64_H
10#define _ASM_PGTABLE_64_H
11
12#include <linux/compiler.h>
13#include <linux/linkage.h>
14
15#include <asm/addrspace.h>
16#include <asm/page.h>
17#include <asm/cachectl.h>
18#include <asm/fixmap.h>
19
20#if CONFIG_PGTABLE_LEVELS == 2
21#include <asm-generic/pgtable-nopmd.h>
22#elif CONFIG_PGTABLE_LEVELS == 3
23#include <asm-generic/pgtable-nopud.h>
24#else
25#include <asm-generic/pgtable-nop4d.h>
26#endif
27
28/*
29 * Each address space has 2 4K pages as its page directory, giving 1024
30 * (== PTRS_PER_PGD) 8 byte pointers to pmd tables. Each pmd table is a
31 * single 4K page, giving 512 (== PTRS_PER_PMD) 8 byte pointers to page
32 * tables. Each page table is also a single 4K page, giving 512 (==
33 * PTRS_PER_PTE) 8 byte ptes. Each pud entry is initialized to point to
34 * invalid_pmd_table, each pmd entry is initialized to point to
35 * invalid_pte_table, each pte is initialized to 0.
36 *
37 * Kernel mappings: kernel mappings are held in the swapper_pg_table.
38 * The layout is identical to userspace except it's indexed with the
39 * fault address - VMALLOC_START.
40 */
41
42
43/* PGDIR_SHIFT determines what a third-level page table entry can map */
44#ifdef __PAGETABLE_PMD_FOLDED
45#define PGDIR_SHIFT (PAGE_SHIFT + PAGE_SHIFT - 3)
46#else
47
48/* PMD_SHIFT determines the size of the area a second-level page table can map */
49#define PMD_SHIFT (PAGE_SHIFT + (PAGE_SHIFT - 3))
50#define PMD_SIZE (1UL << PMD_SHIFT)
51#define PMD_MASK (~(PMD_SIZE-1))
52
53# ifdef __PAGETABLE_PUD_FOLDED
54# define PGDIR_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_TABLE_ORDER - 3))
55# endif
56#endif
57
58#ifndef __PAGETABLE_PUD_FOLDED
59#define PUD_SHIFT (PMD_SHIFT + (PAGE_SHIFT + PMD_TABLE_ORDER - 3))
60#define PUD_SIZE (1UL << PUD_SHIFT)
61#define PUD_MASK (~(PUD_SIZE-1))
62#define PGDIR_SHIFT (PUD_SHIFT + (PAGE_SHIFT + PUD_TABLE_ORDER - 3))
63#endif
64
65#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
66#define PGDIR_MASK (~(PGDIR_SIZE-1))
67
68/*
69 * For 4kB page size we use a 3 level page tree and an 8kB pud, which
70 * permits us mapping 40 bits of virtual address space.
71 *
72 * We used to implement 41 bits by having an order 1 pmd level but that seemed
73 * rather pointless.
74 *
75 * For 8kB page size we use a 3 level page tree which permits a total of
76 * 8TB of address space. Alternatively a 33-bit / 8GB organization using
77 * two levels would be easy to implement.
78 *
79 * For 16kB page size we use a 2 level page tree which permits a total of
80 * 36 bits of virtual address space. We could add a third level but it seems
81 * like at the moment there's no need for this.
82 *
83 * For 64kB page size we use a 2 level page table tree for a total of 42 bits
84 * of virtual address space.
85 */
86#ifdef CONFIG_PAGE_SIZE_4KB
87# ifdef CONFIG_MIPS_VA_BITS_48
88# define PGD_TABLE_ORDER 0
89# define PUD_TABLE_ORDER 0
90# else
91# define PGD_TABLE_ORDER 1
92# define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud
93# endif
94#define PMD_TABLE_ORDER 0
95#endif
96#ifdef CONFIG_PAGE_SIZE_8KB
97#define PGD_TABLE_ORDER 0
98#define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud
99#define PMD_TABLE_ORDER 0
100#endif
101#ifdef CONFIG_PAGE_SIZE_16KB
102#ifdef CONFIG_MIPS_VA_BITS_48
103#define PGD_TABLE_ORDER 1
104#else
105#define PGD_TABLE_ORDER 0
106#endif
107#define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud
108#define PMD_TABLE_ORDER 0
109#endif
110#ifdef CONFIG_PAGE_SIZE_32KB
111#define PGD_TABLE_ORDER 0
112#define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud
113#define PMD_TABLE_ORDER 0
114#endif
115#ifdef CONFIG_PAGE_SIZE_64KB
116#define PGD_TABLE_ORDER 0
117#define PUD_TABLE_ORDER aieeee_attempt_to_allocate_pud
118#ifdef CONFIG_MIPS_VA_BITS_48
119#define PMD_TABLE_ORDER 0
120#else
121#define PMD_TABLE_ORDER aieeee_attempt_to_allocate_pmd
122#endif
123#endif
124
125#define PTRS_PER_PGD ((PAGE_SIZE << PGD_TABLE_ORDER) / sizeof(pgd_t))
126#ifndef __PAGETABLE_PUD_FOLDED
127#define PTRS_PER_PUD ((PAGE_SIZE << PUD_TABLE_ORDER) / sizeof(pud_t))
128#endif
129#ifndef __PAGETABLE_PMD_FOLDED
130#define PTRS_PER_PMD ((PAGE_SIZE << PMD_TABLE_ORDER) / sizeof(pmd_t))
131#endif
132#define PTRS_PER_PTE (PAGE_SIZE / sizeof(pte_t))
133
134#define USER_PTRS_PER_PGD ((TASK_SIZE64 / PGDIR_SIZE)?(TASK_SIZE64 / PGDIR_SIZE):1)
135
136/*
137 * TLB refill handlers also map the vmalloc area into xuseg. Avoid
138 * the first couple of pages so NULL pointer dereferences will still
139 * reliably trap.
140 */
141#define VMALLOC_START (MAP_BASE + (2 * PAGE_SIZE))
142#define VMALLOC_END \
143 (MAP_BASE + \
144 min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, \
145 (1UL << cpu_vmbits)) - (1UL << 32))
146
147#if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \
148 VMALLOC_START != CKSSEG
149/* Load modules into 32bit-compatible segment. */
150#define MODULES_VADDR CKSSEG
151#define MODULES_END (FIXADDR_START-2*PAGE_SIZE)
152#endif
153
154#define pte_ERROR(e) \
155 printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
156#ifndef __PAGETABLE_PMD_FOLDED
157#define pmd_ERROR(e) \
158 printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
159#endif
160#ifndef __PAGETABLE_PUD_FOLDED
161#define pud_ERROR(e) \
162 printk("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
163#endif
164#define pgd_ERROR(e) \
165 printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
166
167extern pte_t invalid_pte_table[PTRS_PER_PTE];
168
169#ifndef __PAGETABLE_PUD_FOLDED
170/*
171 * For 4-level pagetables we defines these ourselves, for 3-level the
172 * definitions are below, for 2-level the
173 * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
174 */
175typedef struct { unsigned long pud; } pud_t;
176#define pud_val(x) ((x).pud)
177#define __pud(x) ((pud_t) { (x) })
178
179extern pud_t invalid_pud_table[PTRS_PER_PUD];
180
181/*
182 * Empty pgd entries point to the invalid_pud_table.
183 */
184static inline int p4d_none(p4d_t p4d)
185{
186 return p4d_val(p4d) == (unsigned long)invalid_pud_table;
187}
188
189static inline int p4d_bad(p4d_t p4d)
190{
191 if (unlikely(p4d_val(p4d) & ~PAGE_MASK))
192 return 1;
193
194 return 0;
195}
196
197static inline int p4d_present(p4d_t p4d)
198{
199 return p4d_val(p4d) != (unsigned long)invalid_pud_table;
200}
201
202static inline void p4d_clear(p4d_t *p4dp)
203{
204 p4d_val(*p4dp) = (unsigned long)invalid_pud_table;
205}
206
207static inline pud_t *p4d_pgtable(p4d_t p4d)
208{
209 return (pud_t *)p4d_val(p4d);
210}
211
212#define p4d_phys(p4d) virt_to_phys((void *)p4d_val(p4d))
213#define p4d_page(p4d) (pfn_to_page(p4d_phys(p4d) >> PAGE_SHIFT))
214
215#define p4d_index(address) (((address) >> P4D_SHIFT) & (PTRS_PER_P4D - 1))
216
217static inline void set_p4d(p4d_t *p4d, p4d_t p4dval)
218{
219 *p4d = p4dval;
220}
221
222#endif
223
224#ifndef __PAGETABLE_PMD_FOLDED
225/*
226 * For 3-level pagetables we defines these ourselves, for 2-level the
227 * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
228 */
229typedef struct { unsigned long pmd; } pmd_t;
230#define pmd_val(x) ((x).pmd)
231#define __pmd(x) ((pmd_t) { (x) } )
232
233
234extern pmd_t invalid_pmd_table[PTRS_PER_PMD];
235#endif
236
237/*
238 * Empty pgd/pmd entries point to the invalid_pte_table.
239 */
240static inline int pmd_none(pmd_t pmd)
241{
242 return pmd_val(pmd) == (unsigned long) invalid_pte_table;
243}
244
245static inline int pmd_bad(pmd_t pmd)
246{
247#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
248 /* pmd_leaf(pmd) but inline */
249 if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
250 return 0;
251#endif
252
253 if (unlikely(pmd_val(pmd) & ~PAGE_MASK))
254 return 1;
255
256 return 0;
257}
258
259static inline int pmd_present(pmd_t pmd)
260{
261#ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
262 if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
263 return pmd_val(pmd) & _PAGE_PRESENT;
264#endif
265
266 return pmd_val(pmd) != (unsigned long) invalid_pte_table;
267}
268
269static inline void pmd_clear(pmd_t *pmdp)
270{
271 pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
272}
273#ifndef __PAGETABLE_PMD_FOLDED
274
275/*
276 * Empty pud entries point to the invalid_pmd_table.
277 */
278static inline int pud_none(pud_t pud)
279{
280 return pud_val(pud) == (unsigned long) invalid_pmd_table;
281}
282
283static inline int pud_bad(pud_t pud)
284{
285 return pud_val(pud) & ~PAGE_MASK;
286}
287
288static inline int pud_present(pud_t pud)
289{
290 return pud_val(pud) != (unsigned long) invalid_pmd_table;
291}
292
293static inline void pud_clear(pud_t *pudp)
294{
295 pud_val(*pudp) = ((unsigned long) invalid_pmd_table);
296}
297#endif
298
299#define pte_page(x) pfn_to_page(pte_pfn(x))
300
301#define pte_pfn(x) ((unsigned long)((x).pte >> PFN_PTE_SHIFT))
302#define pfn_pte(pfn, prot) __pte(((pfn) << PFN_PTE_SHIFT) | pgprot_val(prot))
303#define pfn_pmd(pfn, prot) __pmd(((pfn) << PFN_PTE_SHIFT) | pgprot_val(prot))
304
305#ifndef __PAGETABLE_PMD_FOLDED
306static inline pmd_t *pud_pgtable(pud_t pud)
307{
308 return (pmd_t *)pud_val(pud);
309}
310#define pud_phys(pud) virt_to_phys((void *)pud_val(pud))
311#define pud_page(pud) (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT))
312
313#endif
314
315/*
316 * Initialize a new pgd / pud / pmd table with invalid pointers.
317 */
318extern void pgd_init(void *addr);
319extern void pud_init(void *addr);
320#define pud_init pud_init
321extern void pmd_init(void *addr);
322#define pmd_init pmd_init
323
324/*
325 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
326 * are !pte_none() && !pte_present().
327 *
328 * Format of swap PTEs:
329 *
330 * 6 6 6 6 5 5 5 5 5 5 5 5 5 5 4 4 4 4 4 4 4 4 4 4 3 3 3 3 3 3 3 3
331 * 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2
332 * <--------------------------- offset ---------------------------
333 *
334 * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
335 * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
336 * --------------> E <-- type ---> <---------- zeroes ----------->
337 *
338 * E is the exclusive marker that is not stored in swap entries.
339 */
340static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
341{ pte_t pte; pte_val(pte) = ((type & 0x7f) << 16) | (offset << 24); return pte; }
342
343#define __swp_type(x) (((x).val >> 16) & 0x7f)
344#define __swp_offset(x) ((x).val >> 24)
345#define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) })
346#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
347#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
348
349/* We borrow bit 23 to store the exclusive marker in swap PTEs. */
350#define _PAGE_SWP_EXCLUSIVE (1 << 23)
351
352#endif /* _ASM_PGTABLE_64_H */