xref: /openbmc/linux/arch/mips/include/asm/pgtable-64.h (revision 0e17c50f)
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 + PTE_ORDER - 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 + PTE_ORDER - 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_ORDER - 3))
55 # endif
56 #endif
57 
58 #ifndef __PAGETABLE_PUD_FOLDED
59 #define PUD_SHIFT	(PMD_SHIFT + (PAGE_SHIFT + PMD_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_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_ORDER		0
89 #  define PUD_ORDER		0
90 # else
91 #  define PGD_ORDER		1
92 #  define PUD_ORDER		aieeee_attempt_to_allocate_pud
93 # endif
94 #define PMD_ORDER		0
95 #define PTE_ORDER		0
96 #endif
97 #ifdef CONFIG_PAGE_SIZE_8KB
98 #define PGD_ORDER		0
99 #define PUD_ORDER		aieeee_attempt_to_allocate_pud
100 #define PMD_ORDER		0
101 #define PTE_ORDER		0
102 #endif
103 #ifdef CONFIG_PAGE_SIZE_16KB
104 #ifdef CONFIG_MIPS_VA_BITS_48
105 #define PGD_ORDER               1
106 #else
107 #define PGD_ORDER               0
108 #endif
109 #define PUD_ORDER		aieeee_attempt_to_allocate_pud
110 #define PMD_ORDER		0
111 #define PTE_ORDER		0
112 #endif
113 #ifdef CONFIG_PAGE_SIZE_32KB
114 #define PGD_ORDER		0
115 #define PUD_ORDER		aieeee_attempt_to_allocate_pud
116 #define PMD_ORDER		0
117 #define PTE_ORDER		0
118 #endif
119 #ifdef CONFIG_PAGE_SIZE_64KB
120 #define PGD_ORDER		0
121 #define PUD_ORDER		aieeee_attempt_to_allocate_pud
122 #ifdef CONFIG_MIPS_VA_BITS_48
123 #define PMD_ORDER		0
124 #else
125 #define PMD_ORDER		aieeee_attempt_to_allocate_pmd
126 #endif
127 #define PTE_ORDER		0
128 #endif
129 
130 #define PTRS_PER_PGD	((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
131 #ifndef __PAGETABLE_PUD_FOLDED
132 #define PTRS_PER_PUD	((PAGE_SIZE << PUD_ORDER) / sizeof(pud_t))
133 #endif
134 #ifndef __PAGETABLE_PMD_FOLDED
135 #define PTRS_PER_PMD	((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t))
136 #endif
137 #define PTRS_PER_PTE	((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
138 
139 #define USER_PTRS_PER_PGD       ((TASK_SIZE64 / PGDIR_SIZE)?(TASK_SIZE64 / PGDIR_SIZE):1)
140 #define FIRST_USER_ADDRESS	0UL
141 
142 /*
143  * TLB refill handlers also map the vmalloc area into xuseg.  Avoid
144  * the first couple of pages so NULL pointer dereferences will still
145  * reliably trap.
146  */
147 #define VMALLOC_START		(MAP_BASE + (2 * PAGE_SIZE))
148 #define VMALLOC_END	\
149 	(MAP_BASE + \
150 	 min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, \
151 	     (1UL << cpu_vmbits)) - (1UL << 32))
152 
153 #if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \
154 	VMALLOC_START != CKSSEG
155 /* Load modules into 32bit-compatible segment. */
156 #define MODULE_START	CKSSEG
157 #define MODULE_END	(FIXADDR_START-2*PAGE_SIZE)
158 #endif
159 
160 #define pte_ERROR(e) \
161 	printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
162 #ifndef __PAGETABLE_PMD_FOLDED
163 #define pmd_ERROR(e) \
164 	printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
165 #endif
166 #ifndef __PAGETABLE_PUD_FOLDED
167 #define pud_ERROR(e) \
168 	printk("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
169 #endif
170 #define pgd_ERROR(e) \
171 	printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
172 
173 extern pte_t invalid_pte_table[PTRS_PER_PTE];
174 
175 #ifndef __PAGETABLE_PUD_FOLDED
176 /*
177  * For 4-level pagetables we defines these ourselves, for 3-level the
178  * definitions are below, for 2-level the
179  * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
180  */
181 typedef struct { unsigned long pud; } pud_t;
182 #define pud_val(x)	((x).pud)
183 #define __pud(x)	((pud_t) { (x) })
184 
185 extern pud_t invalid_pud_table[PTRS_PER_PUD];
186 
187 /*
188  * Empty pgd entries point to the invalid_pud_table.
189  */
190 static inline int p4d_none(p4d_t p4d)
191 {
192 	return p4d_val(p4d) == (unsigned long)invalid_pud_table;
193 }
194 
195 static inline int p4d_bad(p4d_t p4d)
196 {
197 	if (unlikely(p4d_val(p4d) & ~PAGE_MASK))
198 		return 1;
199 
200 	return 0;
201 }
202 
203 static inline int p4d_present(p4d_t p4d)
204 {
205 	return p4d_val(p4d) != (unsigned long)invalid_pud_table;
206 }
207 
208 static inline void p4d_clear(p4d_t *p4dp)
209 {
210 	p4d_val(*p4dp) = (unsigned long)invalid_pud_table;
211 }
212 
213 #define pud_index(address)	(((address) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
214 
215 static inline unsigned long p4d_page_vaddr(p4d_t p4d)
216 {
217 	return p4d_val(p4d);
218 }
219 
220 #define p4d_phys(p4d)		virt_to_phys((void *)p4d_val(p4d))
221 #define p4d_page(p4d)		(pfn_to_page(p4d_phys(p4d) >> PAGE_SHIFT))
222 
223 #define p4d_index(address)	(((address) >> P4D_SHIFT) & (PTRS_PER_P4D - 1))
224 
225 static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
226 {
227 	return (pud_t *)p4d_page_vaddr(*p4d) + pud_index(address);
228 }
229 
230 static inline void set_p4d(p4d_t *p4d, p4d_t p4dval)
231 {
232 	*p4d = p4dval;
233 }
234 
235 #endif
236 
237 #ifndef __PAGETABLE_PMD_FOLDED
238 /*
239  * For 3-level pagetables we defines these ourselves, for 2-level the
240  * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
241  */
242 typedef struct { unsigned long pmd; } pmd_t;
243 #define pmd_val(x)	((x).pmd)
244 #define __pmd(x)	((pmd_t) { (x) } )
245 
246 
247 extern pmd_t invalid_pmd_table[PTRS_PER_PMD];
248 #endif
249 
250 /*
251  * Empty pgd/pmd entries point to the invalid_pte_table.
252  */
253 static inline int pmd_none(pmd_t pmd)
254 {
255 	return pmd_val(pmd) == (unsigned long) invalid_pte_table;
256 }
257 
258 static inline int pmd_bad(pmd_t pmd)
259 {
260 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
261 	/* pmd_huge(pmd) but inline */
262 	if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
263 		return 0;
264 #endif
265 
266 	if (unlikely(pmd_val(pmd) & ~PAGE_MASK))
267 		return 1;
268 
269 	return 0;
270 }
271 
272 static inline int pmd_present(pmd_t pmd)
273 {
274 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
275 	if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
276 		return pmd_val(pmd) & _PAGE_PRESENT;
277 #endif
278 
279 	return pmd_val(pmd) != (unsigned long) invalid_pte_table;
280 }
281 
282 static inline void pmd_clear(pmd_t *pmdp)
283 {
284 	pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
285 }
286 #ifndef __PAGETABLE_PMD_FOLDED
287 
288 /*
289  * Empty pud entries point to the invalid_pmd_table.
290  */
291 static inline int pud_none(pud_t pud)
292 {
293 	return pud_val(pud) == (unsigned long) invalid_pmd_table;
294 }
295 
296 static inline int pud_bad(pud_t pud)
297 {
298 	return pud_val(pud) & ~PAGE_MASK;
299 }
300 
301 static inline int pud_present(pud_t pud)
302 {
303 	return pud_val(pud) != (unsigned long) invalid_pmd_table;
304 }
305 
306 static inline void pud_clear(pud_t *pudp)
307 {
308 	pud_val(*pudp) = ((unsigned long) invalid_pmd_table);
309 }
310 #endif
311 
312 #define pte_page(x)		pfn_to_page(pte_pfn(x))
313 
314 #ifdef CONFIG_CPU_VR41XX
315 #define pte_pfn(x)		((unsigned long)((x).pte >> (PAGE_SHIFT + 2)))
316 #define pfn_pte(pfn, prot)	__pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot))
317 #else
318 #define pte_pfn(x)		((unsigned long)((x).pte >> _PFN_SHIFT))
319 #define pfn_pte(pfn, prot)	__pte(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
320 #define pfn_pmd(pfn, prot)	__pmd(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
321 #endif
322 
323 /* to find an entry in a kernel page-table-directory */
324 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
325 
326 #define pgd_index(address)	(((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
327 #define pmd_index(address)	(((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
328 
329 /* to find an entry in a page-table-directory */
330 #define pgd_offset(mm, addr)	((mm)->pgd + pgd_index(addr))
331 
332 #ifndef __PAGETABLE_PMD_FOLDED
333 static inline unsigned long pud_page_vaddr(pud_t pud)
334 {
335 	return pud_val(pud);
336 }
337 #define pud_phys(pud)		virt_to_phys((void *)pud_val(pud))
338 #define pud_page(pud)		(pfn_to_page(pud_phys(pud) >> PAGE_SHIFT))
339 
340 /* Find an entry in the second-level page table.. */
341 static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address)
342 {
343 	return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address);
344 }
345 #endif
346 
347 /* Find an entry in the third-level page table.. */
348 #define __pte_offset(address)						\
349 	(((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
350 #define pte_offset(dir, address)					\
351 	((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
352 #define pte_offset_kernel(dir, address)					\
353 	((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
354 #define pte_offset_map(dir, address)					\
355 	((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
356 #define pte_unmap(pte) ((void)(pte))
357 
358 /*
359  * Initialize a new pgd / pmd table with invalid pointers.
360  */
361 extern void pgd_init(unsigned long page);
362 extern void pud_init(unsigned long page, unsigned long pagetable);
363 extern void pmd_init(unsigned long page, unsigned long pagetable);
364 
365 /*
366  * Non-present pages:  high 40 bits are offset, next 8 bits type,
367  * low 16 bits zero.
368  */
369 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
370 { pte_t pte; pte_val(pte) = (type << 16) | (offset << 24); return pte; }
371 
372 #define __swp_type(x)		(((x).val >> 16) & 0xff)
373 #define __swp_offset(x)		((x).val >> 24)
374 #define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) })
375 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
376 #define __swp_entry_to_pte(x)	((pte_t) { (x).val })
377 
378 #endif /* _ASM_PGTABLE_64_H */
379