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 #include <linux/kernel.h>
16 #else
17 #include <asm/types.h>
18 #endif
19 #include <asm/asm-compat.h>
20 #include <asm/kdump.h>
21
22 /*
23 * On regular PPC32 page size is 4K (but we support 4K/16K/64K/256K pages
24 * on PPC44x). For PPC64 we support either 4K or 64K software
25 * page size. When using 64K pages however, whether we are really supporting
26 * 64K pages in HW or not is irrelevant to those definitions.
27 */
28 #if defined(CONFIG_PPC_256K_PAGES)
29 #define PAGE_SHIFT 18
30 #elif defined(CONFIG_PPC_64K_PAGES)
31 #define PAGE_SHIFT 16
32 #elif defined(CONFIG_PPC_16K_PAGES)
33 #define PAGE_SHIFT 14
34 #else
35 #define PAGE_SHIFT 12
36 #endif
37
38 #define PAGE_SIZE (ASM_CONST(1) << PAGE_SHIFT)
39
40 #ifndef __ASSEMBLY__
41 #ifdef CONFIG_HUGETLB_PAGE
42 extern unsigned int HPAGE_SHIFT;
43 #else
44 #define HPAGE_SHIFT PAGE_SHIFT
45 #endif
46 #define HPAGE_SIZE ((1UL) << HPAGE_SHIFT)
47 #define HPAGE_MASK (~(HPAGE_SIZE - 1))
48 #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT)
49 #define HUGE_MAX_HSTATE (MMU_PAGE_COUNT-1)
50 #endif
51
52 /*
53 * Subtle: (1 << PAGE_SHIFT) is an int, not an unsigned long. So if we
54 * assign PAGE_MASK to a larger type it gets extended the way we want
55 * (i.e. with 1s in the high bits)
56 */
57 #define PAGE_MASK (~((1 << PAGE_SHIFT) - 1))
58
59 /*
60 * KERNELBASE is the virtual address of the start of the kernel, it's often
61 * the same as PAGE_OFFSET, but _might not be_.
62 *
63 * The kdump dump kernel is one example where KERNELBASE != PAGE_OFFSET.
64 *
65 * PAGE_OFFSET is the virtual address of the start of lowmem.
66 *
67 * PHYSICAL_START is the physical address of the start of the kernel.
68 *
69 * MEMORY_START is the physical address of the start of lowmem.
70 *
71 * KERNELBASE, PAGE_OFFSET, and PHYSICAL_START are all configurable on
72 * ppc32 and based on how they are set we determine MEMORY_START.
73 *
74 * For the linear mapping the following equation should be true:
75 * KERNELBASE - PAGE_OFFSET = PHYSICAL_START - MEMORY_START
76 *
77 * Also, KERNELBASE >= PAGE_OFFSET and PHYSICAL_START >= MEMORY_START
78 *
79 * There are two ways to determine a physical address from a virtual one:
80 * va = pa + PAGE_OFFSET - MEMORY_START
81 * va = pa + KERNELBASE - PHYSICAL_START
82 *
83 * If you want to know something's offset from the start of the kernel you
84 * should subtract KERNELBASE.
85 *
86 * If you want to test if something's a kernel address, use is_kernel_addr().
87 */
88
89 #define KERNELBASE ASM_CONST(CONFIG_KERNEL_START)
90 #define PAGE_OFFSET ASM_CONST(CONFIG_PAGE_OFFSET)
91 #define LOAD_OFFSET ASM_CONST((CONFIG_KERNEL_START-CONFIG_PHYSICAL_START))
92
93 #if defined(CONFIG_NONSTATIC_KERNEL)
94 #ifndef __ASSEMBLY__
95
96 extern phys_addr_t memstart_addr;
97 extern phys_addr_t kernstart_addr;
98
99 #ifdef CONFIG_RELOCATABLE_PPC32
100 extern long long virt_phys_offset;
101 #endif
102
103 #endif /* __ASSEMBLY__ */
104 #define PHYSICAL_START kernstart_addr
105
106 #else /* !CONFIG_NONSTATIC_KERNEL */
107 #define PHYSICAL_START ASM_CONST(CONFIG_PHYSICAL_START)
108 #endif
109
110 /* See Description below for VIRT_PHYS_OFFSET */
111 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE)
112 #ifdef CONFIG_RELOCATABLE
113 #define VIRT_PHYS_OFFSET virt_phys_offset
114 #else
115 #define VIRT_PHYS_OFFSET (KERNELBASE - PHYSICAL_START)
116 #endif
117 #endif
118
119 #ifdef CONFIG_PPC64
120 #define MEMORY_START 0UL
121 #elif defined(CONFIG_NONSTATIC_KERNEL)
122 #define MEMORY_START memstart_addr
123 #else
124 #define MEMORY_START (PHYSICAL_START + PAGE_OFFSET - KERNELBASE)
125 #endif
126
127 #ifdef CONFIG_FLATMEM
128 #define ARCH_PFN_OFFSET ((unsigned long)(MEMORY_START >> PAGE_SHIFT))
129 #define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr)
130 #endif
131
132 #define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT)
133 #define virt_to_page(kaddr) pfn_to_page(virt_to_pfn(kaddr))
134 #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT)
135
136 #ifdef CONFIG_PPC_BOOK3S_64
137 /*
138 * On hash the vmalloc and other regions alias to the kernel region when passed
139 * through __pa(), which virt_to_pfn() uses. That means virt_addr_valid() can
140 * return true for some vmalloc addresses, which is incorrect. So explicitly
141 * check that the address is in the kernel region.
142 */
143 #define virt_addr_valid(kaddr) (REGION_ID(kaddr) == KERNEL_REGION_ID && \
144 pfn_valid(virt_to_pfn(kaddr)))
145 #else
146 #define virt_addr_valid(kaddr) pfn_valid(virt_to_pfn(kaddr))
147 #endif
148
149 /*
150 * On Book-E parts we need __va to parse the device tree and we can't
151 * determine MEMORY_START until then. However we can determine PHYSICAL_START
152 * from information at hand (program counter, TLB lookup).
153 *
154 * On BookE with RELOCATABLE (RELOCATABLE_PPC32)
155 *
156 * With RELOCATABLE_PPC32, we support loading the kernel at any physical
157 * address without any restriction on the page alignment.
158 *
159 * We find the runtime address of _stext and relocate ourselves based on
160 * the following calculation:
161 *
162 * virtual_base = ALIGN_DOWN(KERNELBASE,256M) +
163 * MODULO(_stext.run,256M)
164 * and create the following mapping:
165 *
166 * ALIGN_DOWN(_stext.run,256M) => ALIGN_DOWN(KERNELBASE,256M)
167 *
168 * When we process relocations, we cannot depend on the
169 * existing equation for the __va()/__pa() translations:
170 *
171 * __va(x) = (x) - PHYSICAL_START + KERNELBASE
172 *
173 * Where:
174 * PHYSICAL_START = kernstart_addr = Physical address of _stext
175 * KERNELBASE = Compiled virtual address of _stext.
176 *
177 * This formula holds true iff, kernel load address is TLB page aligned.
178 *
179 * In our case, we need to also account for the shift in the kernel Virtual
180 * address.
181 *
182 * E.g.,
183 *
184 * Let the kernel be loaded at 64MB and KERNELBASE be 0xc0000000 (same as PAGE_OFFSET).
185 * In this case, we would be mapping 0 to 0xc0000000, and kernstart_addr = 64M
186 *
187 * Now __va(1MB) = (0x100000) - (0x4000000) + 0xc0000000
188 * = 0xbc100000 , which is wrong.
189 *
190 * Rather, it should be : 0xc0000000 + 0x100000 = 0xc0100000
191 * according to our mapping.
192 *
193 * Hence we use the following formula to get the translations right:
194 *
195 * __va(x) = (x) - [ PHYSICAL_START - Effective KERNELBASE ]
196 *
197 * Where :
198 * PHYSICAL_START = dynamic load address.(kernstart_addr variable)
199 * Effective KERNELBASE = virtual_base =
200 * = ALIGN_DOWN(KERNELBASE,256M) +
201 * MODULO(PHYSICAL_START,256M)
202 *
203 * To make the cost of __va() / __pa() more light weight, we introduce
204 * a new variable virt_phys_offset, which will hold :
205 *
206 * virt_phys_offset = Effective KERNELBASE - PHYSICAL_START
207 * = ALIGN_DOWN(KERNELBASE,256M) -
208 * ALIGN_DOWN(PHYSICALSTART,256M)
209 *
210 * Hence :
211 *
212 * __va(x) = x - PHYSICAL_START + Effective KERNELBASE
213 * = x + virt_phys_offset
214 *
215 * and
216 * __pa(x) = x + PHYSICAL_START - Effective KERNELBASE
217 * = x - virt_phys_offset
218 *
219 * On non-Book-E PPC64 PAGE_OFFSET and MEMORY_START are constants so use
220 * the other definitions for __va & __pa.
221 */
222 #if defined(CONFIG_PPC32) && defined(CONFIG_BOOKE)
223 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + VIRT_PHYS_OFFSET))
224 #define __pa(x) ((unsigned long)(x) - VIRT_PHYS_OFFSET)
225 #else
226 #ifdef CONFIG_PPC64
227 /*
228 * gcc miscompiles (unsigned long)(&static_var) - PAGE_OFFSET
229 * with -mcmodel=medium, so we use & and | instead of - and + on 64-bit.
230 */
231 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) | PAGE_OFFSET))
232 #define __pa(x) ((unsigned long)(x) & 0x0fffffffffffffffUL)
233
234 #else /* 32-bit, non book E */
235 #define __va(x) ((void *)(unsigned long)((phys_addr_t)(x) + PAGE_OFFSET - MEMORY_START))
236 #define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + MEMORY_START)
237 #endif
238 #endif
239
240 /*
241 * Unfortunately the PLT is in the BSS in the PPC32 ELF ABI,
242 * and needs to be executable. This means the whole heap ends
243 * up being executable.
244 */
245 #define VM_DATA_DEFAULT_FLAGS32 (VM_READ | VM_WRITE | VM_EXEC | \
246 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
247
248 #define VM_DATA_DEFAULT_FLAGS64 (VM_READ | VM_WRITE | \
249 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
250
251 #ifdef __powerpc64__
252 #include <asm/page_64.h>
253 #else
254 #include <asm/page_32.h>
255 #endif
256
257 /* align addr on a size boundary - adjust address up/down if needed */
258 #define _ALIGN_UP(addr, size) __ALIGN_KERNEL(addr, size)
259 #define _ALIGN_DOWN(addr, size) ((addr)&(~((typeof(addr))(size)-1)))
260
261 /* align addr on a size boundary - adjust address up if needed */
262 #define _ALIGN(addr,size) _ALIGN_UP(addr,size)
263
264 /*
265 * Don't compare things with KERNELBASE or PAGE_OFFSET to test for
266 * "kernelness", use is_kernel_addr() - it should do what you want.
267 */
268 #ifdef CONFIG_PPC_BOOK3E_64
269 #define is_kernel_addr(x) ((x) >= 0x8000000000000000ul)
270 #else
271 #define is_kernel_addr(x) ((x) >= PAGE_OFFSET)
272 #endif
273
274 #ifndef CONFIG_PPC_BOOK3S_64
275 /*
276 * Use the top bit of the higher-level page table entries to indicate whether
277 * the entries we point to contain hugepages. This works because we know that
278 * the page tables live in kernel space. If we ever decide to support having
279 * page tables at arbitrary addresses, this breaks and will have to change.
280 */
281 #ifdef CONFIG_PPC64
282 #define PD_HUGE 0x8000000000000000
283 #else
284 #define PD_HUGE 0x80000000
285 #endif
286 #endif /* CONFIG_PPC_BOOK3S_64 */
287
288 /*
289 * Some number of bits at the level of the page table that points to
290 * a hugepte are used to encode the size. This masks those bits.
291 */
292 #define HUGEPD_SHIFT_MASK 0x3f
293
294 #ifndef __ASSEMBLY__
295
296 #ifdef CONFIG_STRICT_MM_TYPECHECKS
297 /* These are used to make use of C type-checking. */
298
299 /* PTE level */
300 typedef struct { pte_basic_t pte; } pte_t;
301 #define pte_val(x) ((x).pte)
302 #define __pte(x) ((pte_t) { (x) })
303
304 /* 64k pages additionally define a bigger "real PTE" type that gathers
305 * the "second half" part of the PTE for pseudo 64k pages
306 */
307 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
308 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
309 #else
310 typedef struct { pte_t pte; } real_pte_t;
311 #endif
312
313 /* PMD level */
314 #ifdef CONFIG_PPC64
315 typedef struct { unsigned long pmd; } pmd_t;
316 #define pmd_val(x) ((x).pmd)
317 #define __pmd(x) ((pmd_t) { (x) })
318
319 /* PUD level exusts only on 4k pages */
320 #ifndef CONFIG_PPC_64K_PAGES
321 typedef struct { unsigned long pud; } pud_t;
322 #define pud_val(x) ((x).pud)
323 #define __pud(x) ((pud_t) { (x) })
324 #endif /* !CONFIG_PPC_64K_PAGES */
325 #endif /* CONFIG_PPC64 */
326
327 /* PGD level */
328 typedef struct { unsigned long pgd; } pgd_t;
329 #define pgd_val(x) ((x).pgd)
330 #define __pgd(x) ((pgd_t) { (x) })
331
332 /* Page protection bits */
333 typedef struct { unsigned long pgprot; } pgprot_t;
334 #define pgprot_val(x) ((x).pgprot)
335 #define __pgprot(x) ((pgprot_t) { (x) })
336
337 #else
338
339 /*
340 * .. while these make it easier on the compiler
341 */
342
343 typedef pte_basic_t pte_t;
344 #define pte_val(x) (x)
345 #define __pte(x) (x)
346
347 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC_STD_MMU_64)
348 typedef struct { pte_t pte; unsigned long hidx; } real_pte_t;
349 #else
350 typedef pte_t real_pte_t;
351 #endif
352
353
354 #ifdef CONFIG_PPC64
355 typedef unsigned long pmd_t;
356 #define pmd_val(x) (x)
357 #define __pmd(x) (x)
358
359 #ifndef CONFIG_PPC_64K_PAGES
360 typedef unsigned long pud_t;
361 #define pud_val(x) (x)
362 #define __pud(x) (x)
363 #endif /* !CONFIG_PPC_64K_PAGES */
364 #endif /* CONFIG_PPC64 */
365
366 typedef unsigned long pgd_t;
367 #define pgd_val(x) (x)
368 #define pgprot_val(x) (x)
369
370 typedef unsigned long pgprot_t;
371 #define __pgd(x) (x)
372 #define __pgprot(x) (x)
373
374 #endif
375
376 typedef struct { signed long pd; } hugepd_t;
377
378 #ifdef CONFIG_HUGETLB_PAGE
379 #ifdef CONFIG_PPC_BOOK3S_64
380 #ifdef CONFIG_PPC_64K_PAGES
381 /*
382 * With 64k page size, we have hugepage ptes in the pgd and pmd entries. We don't
383 * need to setup hugepage directory for them. Our pte and page directory format
384 * enable us to have this enabled. But to avoid errors when implementing new
385 * features disable hugepd for 64K. We enable a debug version here, So we catch
386 * wrong usage.
387 */
388 #ifdef CONFIG_DEBUG_VM
389 extern int hugepd_ok(hugepd_t hpd);
390 #else
391 #define hugepd_ok(x) (0)
392 #endif
393 #else
hugepd_ok(hugepd_t hpd)394 static inline int hugepd_ok(hugepd_t hpd)
395 {
396 /*
397 * hugepd pointer, bottom two bits == 00 and next 4 bits
398 * indicate size of table
399 */
400 return (((hpd.pd & 0x3) == 0x0) && ((hpd.pd & HUGEPD_SHIFT_MASK) != 0));
401 }
402 #endif
403 #else
hugepd_ok(hugepd_t hpd)404 static inline int hugepd_ok(hugepd_t hpd)
405 {
406 return (hpd.pd > 0);
407 }
408 #endif
409
410 #define is_hugepd(hpd) (hugepd_ok(hpd))
411 #define pgd_huge pgd_huge
412 int pgd_huge(pgd_t pgd);
413 #else /* CONFIG_HUGETLB_PAGE */
414 #define is_hugepd(pdep) 0
415 #define pgd_huge(pgd) 0
416 #endif /* CONFIG_HUGETLB_PAGE */
417 #define __hugepd(x) ((hugepd_t) { (x) })
418
419 struct page;
420 extern void clear_user_page(void *page, unsigned long vaddr, struct page *pg);
421 extern void copy_user_page(void *to, void *from, unsigned long vaddr,
422 struct page *p);
423 extern int page_is_ram(unsigned long pfn);
424 extern int devmem_is_allowed(unsigned long pfn);
425
426 #ifdef CONFIG_PPC_SMLPAR
427 void arch_free_page(struct page *page, int order);
428 #define HAVE_ARCH_FREE_PAGE
429 #endif
430
431 struct vm_area_struct;
432
433 #if defined(CONFIG_PPC_64K_PAGES) && defined(CONFIG_PPC64)
434 typedef pte_t *pgtable_t;
435 #else
436 typedef struct page *pgtable_t;
437 #endif
438
439 #include <asm-generic/memory_model.h>
440 #endif /* __ASSEMBLY__ */
441
442 #endif /* _ASM_POWERPC_PAGE_H */
443