1 #ifndef _ASM_POWERPC_PAGE_H
2 #define _ASM_POWERPC_PAGE_H
3
4 /*
5 * Copyright (C) 2001,2005 IBM Corporation.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13 #ifndef __ASSEMBLY__
14 #include <linux/types.h>
15 #else
16 #include <asm/types.h>
17 #endif
18 #include <asm/asm-compat.h>
19 #include <asm/kdump.h>
20
21 /*
22 * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages
23 * on PPC44x). For PPC64 we support either 4K or 64K software
24 * page size. When using 64K pages however, whether we are really supporting
25 * 64K pages in HW or not is irrelevant to those definitions.
26 */
27 #if defined(CONFIG_PPC_256K_PAGES)
28 #define PAGE_SHIFT 18
29 #elif defined(CONFIG_PPC_64K_PAGES)
30 #define PAGE_SHIFT 16
31 #elif defined(CONFIG_PPC_16K_PAGES)
32 #define PAGE_SHIFT 14
33 #else
34 #define PAGE_SHIFT 12
35 #endif
36
37 #define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT)
38
39 #ifndef __ASSEMBLY__
40 #ifdef CONFIG_HUGETLB_PAGE
41 extern unsigned int HPAGE_SHIFT;
42 #else
43 #define HPAGE_SHIFT PAGE_SHIFT
44 #endif
45 #define HPAGE_SIZE ((1UL) << HPAGE_SHIFT)
46 #define HPAGE_MASK (~(HPAGE_SIZE - 1))
47 #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
48 #define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1)
49 #endif
50
51 /* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
52 #define __HAVE_ARCH_GATE_AREA 1
53
54 /*
55 * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
56 * assign PAGE_MASK to a larger type it gets extended the way we want
57 * (i.e. with 1s in the high bits)
58 */
59 #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
60
61 /*
62 * KERNELBASE is the virtual address of the start of the kernel, it's often
63 * the same as PAGE_OFFSET, but _might not be_.
64 *
65 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
66 *
67 * PAGE_OFFSET is the virtual address of the start of lowmem.
68 *
69 * PHYSICAL_START is the physical address of the start of the kernel.
70 *
71 * MEMORY_START is the physical address of the start of lowmem.
72 *
73 * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
74 * ppc32 and based on how they are set we determine MEMORY_START.
75 *
76 * For the linear mapping the following equation should be true:
77 * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
78 *
79 * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
80 *
81 * There are two was to determine a physical address from a virtual one:
82 * va = pa + PAGE_OFFSET - MEMORY_START
83 * va = pa + KERNELBASE - PHYSICAL_START
84 *
85 * If you want to know something's offset from the start of the kernel you
86 * should subtract KERNELBASE.
87 *
88 * If you want to test if something's a kernel address, use is_kernel_addr().
89 */
90
91 #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
92 #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
93 #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
94
95 #if defined(CONFIG_NONSTATIC_KERNEL)
96 #ifndef __ASSEMBLY__
97
98 extern phys_addr_t memstart_addr;
99 extern phys_addr_t kernstart_addr;
100
101 #ifdef CONFIG_RELOCATABLE_PPC32
102 extern long long virt_phys_offset;
103 #endif
104
105 #endif /* __ASSEMBLY__ */
106 #define PHYSICAL_START kernstart_addr
107
108 #else /* !CONFIG_NONSTATIC_KERNEL */
109 #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START)
110 #endif
111
112 /* See Description below for VIRT_PHYS_OFFSET */
113 #ifdef CONFIG_RELOCATABLE_PPC32
114 #define VIRT_PHYS_OFFSET virt_phys_offset
115 #else
116 #define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START)
117 #endif
118
119
120 #ifdef CONFIG_PPC64
121 #define MEMORY_START 0UL
122 #elif defined(CONFIG_NONSTATIC_KERNEL)
123 #define MEMORY_START memstart_addr
124 #else
125 #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
126 #endif
127
128 #ifdef CONFIG_FLATMEM
129 #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT))
130 #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr)
131 #endif
132
133 #define virt_to_page(kaddr) pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
134 #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
135 #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT)
136
137 /*
138 * On Book-E parts we need __va to parse the device tree and we can't
139 * determine MEMORY_START until then. However we can determine PHYSICAL_START
140 * from information at hand (program counter, TLB lookup).
141 *
142 * On BookE with RELOCATABLE (RELOCATABLE_PPC32)
143 *
144 * With RELOCATABLE_PPC32, we support loading the kernel at any physical
145 * address without any restriction on the page alignment.
146 *
147 * We find the runtime address of _stext and relocate ourselves based on
148 * the following calculation:
149 *
150 * virtual_base = ALIGN_DOWN(KERNELBASE,256M) +
151 * MODULO(_stext.run,256M)
152 * and create the following mapping:
153 *
154 * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M)
155 *
156 * When we process relocations, we cannot depend on the
157 * existing equation for the __va()/__pa() translations:
158 *
159 * __va(x) = (x) - PHYSICAL_START + KERNELBASE
160 *
161 * Where:
162 * PHYSICAL_START = kernstart_addr = Physical address of _stext
163 * KERNELBASE = Compiled virtual address of _stext.
164 *
165 * This formula holds true iff, kernel load address is TLB page aligned.
166 *
167 * In our case, we need to also account for the shift in the kernel Virtual
168 * address.
169 *
170 * E.g.,
171 *
172 * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET).
173 * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M
174 *
175 * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000
176 * = 0xbc100000 , which is wrong.
177 *
178 * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000
179 * according to our mapping.
180 *
181 * Hence we use the following formula to get the translations right:
182 *
183 * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ]
184 *
185 * Where :
186 * PHYSICAL_START = dynamic load address.(kernstart_addr variable)
187 * Effective KERNELBASE = virtual_base =
188 * = ALIGN_DOWN(KERNELBASE,256M) +
189 * MODULO(PHYSICAL_START,256M)
190 *
191 * To make the cost of __va() / __pa() more light weight, we introduce
192 * a new variable virt_phys_offset, which will hold :
193 *
194 * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START
195 * = ALIGN_DOWN(KERNELBASE,256M) -
196 * ALIGN_DOWN(PHYSICALSTART,256M)
197 *
198 * Hence :
199 *
200 * __va(x) = x - PHYSICAL_START + Effective KERNELBASE
201 * = x + virt_phys_offset
202 *
203 * and
204 * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE
205 * = x - virt_phys_offset
206 *
207 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use
208 * the other definitions for __va & __pa.
209 */
210 #ifdef CONFIG_BOOKE
211 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET))
212 #define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET)
213 #else
214 #ifdef CONFIG_PPC64
215 /*
216 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET
217 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit.
218 */
219 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET))
220 #define __pa(x) ((unsigned long)(x) & 0x0fffffffffffffffUL)
221
222 #else /* 32-bit, non book E */
223 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START))
224 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
225 #endif
226 #endif
227
228 /*
229 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
230 * and needs to be executable. This means the whole heap ends
231 * up being executable.
232 */
233 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
234 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
235
236 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
237 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
238
239 #ifdef __powerpc64__
240 #include <asm/page_64.h>
241 #else
242 #include <asm/page_32.h>
243 #endif
244
245 /* align addr on a size boundary - adjust address up/down if needed */
246 #define _ALIGN_UP(addr,size) (((addr)+((size)-1))&(~((size)-1)))
247 #define _ALIGN_DOWN(addr,size) ((addr)&(~((size)-1)))
248
249 /* align addr on a size boundary - adjust address up if needed */
250 #define _ALIGN(addr,size) _ALIGN_UP(addr,size)
251
252 /*
253 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
254 * "kernelness", use is_kernel_addr() - it should do what you want.
255 */
256 #ifdef CONFIG_PPC_BOOK3E_64
257 #define is_kernel_addr(x) ((x) >= 0x8000000000000000ul)
258 #else
259 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET)
260 #endif
261
262 /*
263 * Use the top bit of the higher-level page table entries to indicate whether
264 * the entries we point to contain hugepages. This works because we know that
265 * the page tables live in kernel space. If we ever decide to support having
266 * page tables at arbitrary addresses, this breaks and will have to change.
267 */
268 #ifdef CONFIG_PPC64
269 #define PD_HUGE 0x8000000000000000
270 #else
271 #define PD_HUGE 0x80000000
272 #endif
273
274 /*
275 * Some number of bits at the level of the page table that points to
276 * a hugepte are used to encode the size. This masks those bits.
277 */
278 #define HUGEPD_SHIFT_MASK 0x3f
279
280 #ifndef __ASSEMBLY__
281
282 #undef STRICT_MM_TYPECHECKS
283
284 #ifdef STRICT_MM_TYPECHECKS
285 /* These are used to make use of C type-checking. */
286
287 /* PTE level */
288 typedef struct { pte_basic_t pte; } pte_t;
289 #define pte_val(x) ((x).pte)
290 #define __pte(x) ((pte_t) { (x) })
291
292 /* 64k pages additionally define a bigger "real PTE" type that gathers
293 * the "second half" part of the PTE for pseudo 64k pages
294 */
295 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
296 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
297 #else
298 typedef struct { pte_t pte; } real_pte_t;
299 #endif
300
301 /* PMD level */
302 #ifdef CONFIG_PPC64
303 typedef struct { unsigned long pmd; } pmd_t;
304 #define pmd_val(x) ((x).pmd)
305 #define __pmd(x) ((pmd_t) { (x) })
306
307 /* PUD level exusts only on 4k pages */
308 #ifndef CONFIG_PPC_64K_PAGES
309 typedef struct { unsigned long pud; } pud_t;
310 #define pud_val(x) ((x).pud)
311 #define __pud(x) ((pud_t) { (x) })
312 #endif /* !CONFIG_PPC_64K_PAGES */
313 #endif /* CONFIG_PPC64 */
314
315 /* PGD level */
316 typedef struct { unsigned long pgd; } pgd_t;
317 #define pgd_val(x) ((x).pgd)
318 #define __pgd(x) ((pgd_t) { (x) })
319
320 /* Page protection bits */
321 typedef struct { unsigned long pgprot; } pgprot_t;
322 #define pgprot_val(x) ((x).pgprot)
323 #define __pgprot(x) ((pgprot_t) { (x) })
324
325 #else
326
327 /*
328 * .. while these make it easier on the compiler
329 */
330
331 typedef pte_basic_t pte_t;
332 #define pte_val(x) (x)
333 #define __pte(x) (x)
334
335 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
336 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
337 #else
338 typedef pte_t real_pte_t;
339 #endif
340
341
342 #ifdef CONFIG_PPC64
343 typedef unsigned long pmd_t;
344 #define pmd_val(x) (x)
345 #define __pmd(x) (x)
346
347 #ifndef CONFIG_PPC_64K_PAGES
348 typedef unsigned long pud_t;
349 #define pud_val(x) (x)
350 #define __pud(x) (x)
351 #endif /* !CONFIG_PPC_64K_PAGES */
352 #endif /* CONFIG_PPC64 */
353
354 typedef unsigned long pgd_t;
355 #define pgd_val(x) (x)
356 #define pgprot_val(x) (x)
357
358 typedef unsigned long pgprot_t;
359 #define __pgd(x) (x)
360 #define __pgprot(x) (x)
361
362 #endif
363
364 typedef struct { signed long pd; } hugepd_t;
365
366 #ifdef CONFIG_HUGETLB_PAGE
hugepd_ok(hugepd_t hpd)367 static inline int hugepd_ok(hugepd_t hpd)
368 {
369 return (hpd.pd > 0);
370 }
371
372 #define is_hugepd(pdep) (hugepd_ok(*((hugepd_t *)(pdep))))
373 #else /* CONFIG_HUGETLB_PAGE */
374 #define is_hugepd(pdep) 0
375 #endif /* CONFIG_HUGETLB_PAGE */
376
377 struct page;
378 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
379 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
380 struct page *p);
381 extern int page_is_ram(unsigned long pfn);
382 extern int devmem_is_allowed(unsigned long pfn);
383
384 #ifdef CONFIG_PPC_SMLPAR
385 void arch_free_page(struct page *page, int order);
386 #define HAVE_ARCH_FREE_PAGE
387 #endif
388
389 struct vm_area_struct;
390
391 typedef struct page *pgtable_t;
392
393 #include <asm-generic/memory_model.h>
394 #endif /* __ASSEMBLY__ */
395
396 #endif /* _ASM_POWERPC_PAGE_H */
397