?  search:
summary | log | graphiclog1 | graphiclog2 | commit | commitdiff | tree | refs | edit | fork
blame | history | raw | HEAD
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
[linux-btrfs-devel.git] / arch / arm / mm / mmu.c
blob226f1804be12ed305abaa3156cc49982f2049d82
1 /*
2 * linux/arch/arm/mm/mmu.c
3 *
4 * Copyright (C) 1995-2005 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10 #include <linux/module.h>
11 #include <linux/kernel.h>
12 #include <linux/errno.h>
13 #include <linux/init.h>
14 #include <linux/mman.h>
15 #include <linux/nodemask.h>
16 #include <linux/memblock.h>
17 #include <linux/fs.h>
18
19 #include <asm/cputype.h>
20 #include <asm/sections.h>
21 #include <asm/cachetype.h>
22 #include <asm/setup.h>
23 #include <asm/sizes.h>
24 #include <asm/smp_plat.h>
25 #include <asm/tlb.h>
26 #include <asm/highmem.h>
27 #include <asm/traps.h>
28
29 #include <asm/mach/arch.h>
30 #include <asm/mach/map.h>
31
32 #include "mm.h"
33
34 /*
35 * empty_zero_page is a special page that is used for
36 * zero-initialized data and COW.
37 */
38 struct page *empty_zero_page;
39 EXPORT_SYMBOL(empty_zero_page);
40
41 /*
42 * The pmd table for the upper-most set of pages.
43 */
44 pmd_t *top_pmd;
45
46 #define CPOLICY_UNCACHED 0
47 #define CPOLICY_BUFFERED 1
48 #define CPOLICY_WRITETHROUGH 2
49 #define CPOLICY_WRITEBACK 3
50 #define CPOLICY_WRITEALLOC 4
51
52 static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK;
53 static unsigned int ecc_mask __initdata = 0;
54 pgprot_t pgprot_user;
55 pgprot_t pgprot_kernel;
56
57 EXPORT_SYMBOL(pgprot_user);
58 EXPORT_SYMBOL(pgprot_kernel);
59
60 struct cachepolicy {
61 const char policy[16];
62 unsigned int cr_mask;
63 pmdval_t pmd;
64 pteval_t pte;
65 };
66
67 static struct cachepolicy cache_policies[] __initdata = {
68 {
69 .policy = "uncached",
70 .cr_mask = CR_W|CR_C,
71 .pmd = PMD_SECT_UNCACHED,
72 .pte = L_PTE_MT_UNCACHED,
73 }, {
74 .policy = "buffered",
75 .cr_mask = CR_C,
76 .pmd = PMD_SECT_BUFFERED,
77 .pte = L_PTE_MT_BUFFERABLE,
78 }, {
79 .policy = "writethrough",
80 .cr_mask = 0,
81 .pmd = PMD_SECT_WT,
82 .pte = L_PTE_MT_WRITETHROUGH,
83 }, {
84 .policy = "writeback",
85 .cr_mask = 0,
86 .pmd = PMD_SECT_WB,
87 .pte = L_PTE_MT_WRITEBACK,
88 }, {
89 .policy = "writealloc",
90 .cr_mask = 0,
91 .pmd = PMD_SECT_WBWA,
92 .pte = L_PTE_MT_WRITEALLOC,
93 }
94 };
95
96 /*
97 * These are useful for identifying cache coherency
98 * problems by allowing the cache or the cache and
99 * writebuffer to be turned off. (Note: the write
100 * buffer should not be on and the cache off).
101 */
102 static int __init early_cachepolicy(char *p)
103 {
104 int i;
105
106 for (i = 0; i < ARRAY_SIZE(cache_policies); i++) {
107 int len = strlen(cache_policies[i].policy);
108
109 if (memcmp(p, cache_policies[i].policy, len) == 0) {
110 cachepolicy = i;
111 cr_alignment &= ~cache_policies[i].cr_mask;
112 cr_no_alignment &= ~cache_policies[i].cr_mask;
113 break;
114 }
115 }
116 if (i == ARRAY_SIZE(cache_policies))
117 printk(KERN_ERR "ERROR: unknown or unsupported cache policy\n");
118 /*
119 * This restriction is partly to do with the way we boot; it is
120 * unpredictable to have memory mapped using two different sets of
121 * memory attributes (shared, type, and cache attribs). We can not
122 * change these attributes once the initial assembly has setup the
123 * page tables.
124 */
125 if (cpu_architecture() >= CPU_ARCH_ARMv6) {
126 printk(KERN_WARNING "Only cachepolicy=writeback supported on ARMv6 and later\n");
127 cachepolicy = CPOLICY_WRITEBACK;
128 }
129 flush_cache_all();
130 set_cr(cr_alignment);
131 return 0;
132 }
133 early_param("cachepolicy", early_cachepolicy);
134
135 static int __init early_nocache(char *__unused)
136 {
137 char *p = "buffered";
138 printk(KERN_WARNING "nocache is deprecated; use cachepolicy=%s\n", p);
139 early_cachepolicy(p);
140 return 0;
141 }
142 early_param("nocache", early_nocache);
143
144 static int __init early_nowrite(char *__unused)
145 {
146 char *p = "uncached";
147 printk(KERN_WARNING "nowb is deprecated; use cachepolicy=%s\n", p);
148 early_cachepolicy(p);
149 return 0;
150 }
151 early_param("nowb", early_nowrite);
152
153 static int __init early_ecc(char *p)
154 {
155 if (memcmp(p, "on", 2) == 0)
156 ecc_mask = PMD_PROTECTION;
157 else if (memcmp(p, "off", 3) == 0)
158 ecc_mask = 0;
159 return 0;
160 }
161 early_param("ecc", early_ecc);
162
163 static int __init noalign_setup(char *__unused)
164 {
165 cr_alignment &= ~CR_A;
166 cr_no_alignment &= ~CR_A;
167 set_cr(cr_alignment);
168 return 1;
169 }
170 __setup("noalign", noalign_setup);
171
172 #ifndef CONFIG_SMP
173 void adjust_cr(unsigned long mask, unsigned long set)
174 {
175 unsigned long flags;
176
177 mask &= ~CR_A;
178
179 set &= mask;
180
181 local_irq_save(flags);
182
183 cr_no_alignment = (cr_no_alignment & ~mask) | set;
184 cr_alignment = (cr_alignment & ~mask) | set;
185
186 set_cr((get_cr() & ~mask) | set);
187
188 local_irq_restore(flags);
189 }
190 #endif
191
192 #define PROT_PTE_DEVICE L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_XN
193 #define PROT_SECT_DEVICE PMD_TYPE_SECT|PMD_SECT_AP_WRITE
194
195 static struct mem_type mem_types[] = {
196 [MT_DEVICE] = { /* Strongly ordered / ARMv6 shared device */
197 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_SHARED |
198 L_PTE_SHARED,
199 .prot_l1 = PMD_TYPE_TABLE,
200 .prot_sect = PROT_SECT_DEVICE | PMD_SECT_S,
201 .domain = DOMAIN_IO,
202 },
203 [MT_DEVICE_NONSHARED] = { /* ARMv6 non-shared device */
204 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_NONSHARED,
205 .prot_l1 = PMD_TYPE_TABLE,
206 .prot_sect = PROT_SECT_DEVICE,
207 .domain = DOMAIN_IO,
208 },
209 [MT_DEVICE_CACHED] = { /* ioremap_cached */
210 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_CACHED,
211 .prot_l1 = PMD_TYPE_TABLE,
212 .prot_sect = PROT_SECT_DEVICE | PMD_SECT_WB,
213 .domain = DOMAIN_IO,
214 },
215 [MT_DEVICE_WC] = { /* ioremap_wc */
216 .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_WC,
217 .prot_l1 = PMD_TYPE_TABLE,
218 .prot_sect = PROT_SECT_DEVICE,
219 .domain = DOMAIN_IO,
220 },
221 [MT_UNCACHED] = {
222 .prot_pte = PROT_PTE_DEVICE,
223 .prot_l1 = PMD_TYPE_TABLE,
224 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
225 .domain = DOMAIN_IO,
226 },
227 [MT_CACHECLEAN] = {
228 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
229 .domain = DOMAIN_KERNEL,
230 },
231 [MT_MINICLEAN] = {
232 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN | PMD_SECT_MINICACHE,
233 .domain = DOMAIN_KERNEL,
234 },
235 [MT_LOW_VECTORS] = {
236 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
237 L_PTE_RDONLY,
238 .prot_l1 = PMD_TYPE_TABLE,
239 .domain = DOMAIN_USER,
240 },
241 [MT_HIGH_VECTORS] = {
242 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
243 L_PTE_USER | L_PTE_RDONLY,
244 .prot_l1 = PMD_TYPE_TABLE,
245 .domain = DOMAIN_USER,
246 },
247 [MT_MEMORY] = {
248 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
249 .prot_l1 = PMD_TYPE_TABLE,
250 .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
251 .domain = DOMAIN_KERNEL,
252 },
253 [MT_ROM] = {
254 .prot_sect = PMD_TYPE_SECT,
255 .domain = DOMAIN_KERNEL,
256 },
257 [MT_MEMORY_NONCACHED] = {
258 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
259 L_PTE_MT_BUFFERABLE,
260 .prot_l1 = PMD_TYPE_TABLE,
261 .prot_sect = PMD_TYPE_SECT | PMD_SECT_AP_WRITE,
262 .domain = DOMAIN_KERNEL,
263 },
264 [MT_MEMORY_DTCM] = {
265 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
266 L_PTE_XN,
267 .prot_l1 = PMD_TYPE_TABLE,
268 .prot_sect = PMD_TYPE_SECT | PMD_SECT_XN,
269 .domain = DOMAIN_KERNEL,
270 },
271 [MT_MEMORY_ITCM] = {
272 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY,
273 .prot_l1 = PMD_TYPE_TABLE,
274 .domain = DOMAIN_KERNEL,
275 },
276 };
277
278 const struct mem_type *get_mem_type(unsigned int type)
279 {
280 return type < ARRAY_SIZE(mem_types) ? &mem_types[type] : NULL;
281 }
282 EXPORT_SYMBOL(get_mem_type);
283
284 /*
285 * Adjust the PMD section entries according to the CPU in use.
286 */
287 static void __init build_mem_type_table(void)
288 {
289 struct cachepolicy *cp;
290 unsigned int cr = get_cr();
291 pteval_t user_pgprot, kern_pgprot, vecs_pgprot;
292 int cpu_arch = cpu_architecture();
293 int i;
294
295 if (cpu_arch < CPU_ARCH_ARMv6) {
296 #if defined(CONFIG_CPU_DCACHE_DISABLE)
297 if (cachepolicy > CPOLICY_BUFFERED)
298 cachepolicy = CPOLICY_BUFFERED;
299 #elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
300 if (cachepolicy > CPOLICY_WRITETHROUGH)
301 cachepolicy = CPOLICY_WRITETHROUGH;
302 #endif
303 }
304 if (cpu_arch < CPU_ARCH_ARMv5) {
305 if (cachepolicy >= CPOLICY_WRITEALLOC)
306 cachepolicy = CPOLICY_WRITEBACK;
307 ecc_mask = 0;
308 }
309 if (is_smp())
310 cachepolicy = CPOLICY_WRITEALLOC;
311
312 /*
313 * Strip out features not present on earlier architectures.
314 * Pre-ARMv5 CPUs don't have TEX bits. Pre-ARMv6 CPUs or those
315 * without extended page tables don't have the 'Shared' bit.
316 */
317 if (cpu_arch < CPU_ARCH_ARMv5)
318 for (i = 0; i < ARRAY_SIZE(mem_types); i++)
319 mem_types[i].prot_sect &= ~PMD_SECT_TEX(7);
320 if ((cpu_arch < CPU_ARCH_ARMv6 || !(cr & CR_XP)) && !cpu_is_xsc3())
321 for (i = 0; i < ARRAY_SIZE(mem_types); i++)
322 mem_types[i].prot_sect &= ~PMD_SECT_S;
323
324 /*
325 * ARMv5 and lower, bit 4 must be set for page tables (was: cache
326 * "update-able on write" bit on ARM610). However, Xscale and
327 * Xscale3 require this bit to be cleared.
328 */
329 if (cpu_is_xscale() || cpu_is_xsc3()) {
330 for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
331 mem_types[i].prot_sect &= ~PMD_BIT4;
332 mem_types[i].prot_l1 &= ~PMD_BIT4;
333 }
334 } else if (cpu_arch < CPU_ARCH_ARMv6) {
335 for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
336 if (mem_types[i].prot_l1)
337 mem_types[i].prot_l1 |= PMD_BIT4;
338 if (mem_types[i].prot_sect)
339 mem_types[i].prot_sect |= PMD_BIT4;
340 }
341 }
342
343 /*
344 * Mark the device areas according to the CPU/architecture.
345 */
346 if (cpu_is_xsc3() || (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP))) {
347 if (!cpu_is_xsc3()) {
348 /*
349 * Mark device regions on ARMv6+ as execute-never
350 * to prevent speculative instruction fetches.
351 */
352 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_XN;
353 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_XN;
354 mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_XN;
355 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_XN;
356 }
357 if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
358 /*
359 * For ARMv7 with TEX remapping,
360 * - shared device is SXCB=1100
361 * - nonshared device is SXCB=0100
362 * - write combine device mem is SXCB=0001
363 * (Uncached Normal memory)
364 */
365 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1);
366 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(1);
367 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
368 } else if (cpu_is_xsc3()) {
369 /*
370 * For Xscale3,
371 * - shared device is TEXCB=00101
372 * - nonshared device is TEXCB=01000
373 * - write combine device mem is TEXCB=00100
374 * (Inner/Outer Uncacheable in xsc3 parlance)
375 */
376 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1) | PMD_SECT_BUFFERED;
377 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2);
378 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
379 } else {
380 /*
381 * For ARMv6 and ARMv7 without TEX remapping,
382 * - shared device is TEXCB=00001
383 * - nonshared device is TEXCB=01000
384 * - write combine device mem is TEXCB=00100
385 * (Uncached Normal in ARMv6 parlance).
386 */
387 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED;
388 mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2);
389 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
390 }
391 } else {
392 /*
393 * On others, write combining is "Uncached/Buffered"
394 */
395 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
396 }
397
398 /*
399 * Now deal with the memory-type mappings
400 */
401 cp = &cache_policies[cachepolicy];
402 vecs_pgprot = kern_pgprot = user_pgprot = cp->pte;
403
404 /*
405 * Only use write-through for non-SMP systems
406 */
407 if (!is_smp() && cpu_arch >= CPU_ARCH_ARMv5 && cachepolicy > CPOLICY_WRITETHROUGH)
408 vecs_pgprot = cache_policies[CPOLICY_WRITETHROUGH].pte;
409
410 /*
411 * Enable CPU-specific coherency if supported.
412 * (Only available on XSC3 at the moment.)
413 */
414 if (arch_is_coherent() && cpu_is_xsc3()) {
415 mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
416 mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED;
417 mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
418 mem_types[MT_MEMORY_NONCACHED].prot_pte |= L_PTE_SHARED;
419 }
420 /*
421 * ARMv6 and above have extended page tables.
422 */
423 if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) {
424 /*
425 * Mark cache clean areas and XIP ROM read only
426 * from SVC mode and no access from userspace.
427 */
428 mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
429 mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
430 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
431
432 if (is_smp()) {
433 /*
434 * Mark memory with the "shared" attribute
435 * for SMP systems
436 */
437 user_pgprot |= L_PTE_SHARED;
438 kern_pgprot |= L_PTE_SHARED;
439 vecs_pgprot |= L_PTE_SHARED;
440 mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_S;
441 mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_SHARED;
442 mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_S;
443 mem_types[MT_DEVICE_CACHED].prot_pte |= L_PTE_SHARED;
444 mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
445 mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED;
446 mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_S;
447 mem_types[MT_MEMORY_NONCACHED].prot_pte |= L_PTE_SHARED;
448 }
449 }
450
451 /*
452 * Non-cacheable Normal - intended for memory areas that must
453 * not cause dirty cache line writebacks when used
454 */
455 if (cpu_arch >= CPU_ARCH_ARMv6) {
456 if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
457 /* Non-cacheable Normal is XCB = 001 */
458 mem_types[MT_MEMORY_NONCACHED].prot_sect |=
459 PMD_SECT_BUFFERED;
460 } else {
461 /* For both ARMv6 and non-TEX-remapping ARMv7 */
462 mem_types[MT_MEMORY_NONCACHED].prot_sect |=
463 PMD_SECT_TEX(1);
464 }
465 } else {
466 mem_types[MT_MEMORY_NONCACHED].prot_sect |= PMD_SECT_BUFFERABLE;
467 }
468
469 for (i = 0; i < 16; i++) {
470 unsigned long v = pgprot_val(protection_map[i]);
471 protection_map[i] = __pgprot(v | user_pgprot);
472 }
473
474 mem_types[MT_LOW_VECTORS].prot_pte |= vecs_pgprot;
475 mem_types[MT_HIGH_VECTORS].prot_pte |= vecs_pgprot;
476
477 pgprot_user = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot);
478 pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
479 L_PTE_DIRTY | kern_pgprot);
480
481 mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
482 mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
483 mem_types[MT_MEMORY].prot_sect |= ecc_mask | cp->pmd;
484 mem_types[MT_MEMORY].prot_pte |= kern_pgprot;
485 mem_types[MT_MEMORY_NONCACHED].prot_sect |= ecc_mask;
486 mem_types[MT_ROM].prot_sect |= cp->pmd;
487
488 switch (cp->pmd) {
489 case PMD_SECT_WT:
490 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT;
491 break;
492 case PMD_SECT_WB:
493 case PMD_SECT_WBWA:
494 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WB;
495 break;
496 }
497 printk("Memory policy: ECC %sabled, Data cache %s\n",
498 ecc_mask ? "en" : "dis", cp->policy);
499
500 for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
501 struct mem_type *t = &mem_types[i];
502 if (t->prot_l1)
503 t->prot_l1 |= PMD_DOMAIN(t->domain);
504 if (t->prot_sect)
505 t->prot_sect |= PMD_DOMAIN(t->domain);
506 }
507 }
508
509 #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
510 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
511 unsigned long size, pgprot_t vma_prot)
512 {
513 if (!pfn_valid(pfn))
514 return pgprot_noncached(vma_prot);
515 else if (file->f_flags & O_SYNC)
516 return pgprot_writecombine(vma_prot);
517 return vma_prot;
518 }
519 EXPORT_SYMBOL(phys_mem_access_prot);
520 #endif
521
522 #define vectors_base() (vectors_high() ? 0xffff0000 : 0)
523
524 static void __init *early_alloc(unsigned long sz)
525 {
526 void *ptr = __va(memblock_alloc(sz, sz));
527 memset(ptr, 0, sz);
528 return ptr;
529 }
530
531 static pte_t * __init early_pte_alloc(pmd_t *pmd, unsigned long addr, unsigned long prot)
532 {
533 if (pmd_none(*pmd)) {
534 pte_t *pte = early_alloc(PTE_HWTABLE_OFF + PTE_HWTABLE_SIZE);
535 __pmd_populate(pmd, __pa(pte), prot);
536 }
537 BUG_ON(pmd_bad(*pmd));
538 return pte_offset_kernel(pmd, addr);
539 }
540
541 static void __init alloc_init_pte(pmd_t *pmd, unsigned long addr,
542 unsigned long end, unsigned long pfn,
543 const struct mem_type *type)
544 {
545 pte_t *pte = early_pte_alloc(pmd, addr, type->prot_l1);
546 do {
547 set_pte_ext(pte, pfn_pte(pfn, __pgprot(type->prot_pte)), 0);
548 pfn++;
549 } while (pte++, addr += PAGE_SIZE, addr != end);
550 }
551
552 static void __init alloc_init_section(pud_t *pud, unsigned long addr,
553 unsigned long end, phys_addr_t phys,
554 const struct mem_type *type)
555 {
556 pmd_t *pmd = pmd_offset(pud, addr);
557
558 /*
559 * Try a section mapping - end, addr and phys must all be aligned
560 * to a section boundary. Note that PMDs refer to the individual
561 * L1 entries, whereas PGDs refer to a group of L1 entries making
562 * up one logical pointer to an L2 table.
563 */
564 if (((addr | end | phys) & ~SECTION_MASK) == 0) {
565 pmd_t *p = pmd;
566
567 if (addr & SECTION_SIZE)
568 pmd++;
569
570 do {
571 *pmd = __pmd(phys | type->prot_sect);
572 phys += SECTION_SIZE;
573 } while (pmd++, addr += SECTION_SIZE, addr != end);
574
575 flush_pmd_entry(p);
576 } else {
577 /*
578 * No need to loop; pte's aren't interested in the
579 * individual L1 entries.
580 */
581 alloc_init_pte(pmd, addr, end, __phys_to_pfn(phys), type);
582 }
583 }
584
585 static void alloc_init_pud(pgd_t *pgd, unsigned long addr, unsigned long end,
586 unsigned long phys, const struct mem_type *type)
587 {
588 pud_t *pud = pud_offset(pgd, addr);
589 unsigned long next;
590
591 do {
592 next = pud_addr_end(addr, end);
593 alloc_init_section(pud, addr, next, phys, type);
594 phys += next - addr;
595 } while (pud++, addr = next, addr != end);
596 }
597
598 static void __init create_36bit_mapping(struct map_desc *md,
599 const struct mem_type *type)
600 {
601 unsigned long addr, length, end;
602 phys_addr_t phys;
603 pgd_t *pgd;
604
605 addr = md->virtual;
606 phys = __pfn_to_phys(md->pfn);
607 length = PAGE_ALIGN(md->length);
608
609 if (!(cpu_architecture() >= CPU_ARCH_ARMv6 || cpu_is_xsc3())) {
610 printk(KERN_ERR "MM: CPU does not support supersection "
611 "mapping for 0x%08llx at 0x%08lx\n",
612 (long long)__pfn_to_phys((u64)md->pfn), addr);
613 return;
614 }
615
616 /* N.B. ARMv6 supersections are only defined to work with domain 0.
617 * Since domain assignments can in fact be arbitrary, the
618 * 'domain == 0' check below is required to insure that ARMv6
619 * supersections are only allocated for domain 0 regardless
620 * of the actual domain assignments in use.
621 */
622 if (type->domain) {
623 printk(KERN_ERR "MM: invalid domain in supersection "
624 "mapping for 0x%08llx at 0x%08lx\n",
625 (long long)__pfn_to_phys((u64)md->pfn), addr);
626 return;
627 }
628
629 if ((addr | length | __pfn_to_phys(md->pfn)) & ~SUPERSECTION_MASK) {
630 printk(KERN_ERR "MM: cannot create mapping for 0x%08llx"
631 " at 0x%08lx invalid alignment\n",
632 (long long)__pfn_to_phys((u64)md->pfn), addr);
633 return;
634 }
635
636 /*
637 * Shift bits [35:32] of address into bits [23:20] of PMD
638 * (See ARMv6 spec).
639 */
640 phys |= (((md->pfn >> (32 - PAGE_SHIFT)) & 0xF) << 20);
641
642 pgd = pgd_offset_k(addr);
643 end = addr + length;
644 do {
645 pud_t *pud = pud_offset(pgd, addr);
646 pmd_t *pmd = pmd_offset(pud, addr);
647 int i;
648
649 for (i = 0; i < 16; i++)
650 *pmd++ = __pmd(phys | type->prot_sect | PMD_SECT_SUPER);
651
652 addr += SUPERSECTION_SIZE;
653 phys += SUPERSECTION_SIZE;
654 pgd += SUPERSECTION_SIZE >> PGDIR_SHIFT;
655 } while (addr != end);
656 }
657
658 /*
659 * Create the page directory entries and any necessary
660 * page tables for the mapping specified by `md'. We
661 * are able to cope here with varying sizes and address
662 * offsets, and we take full advantage of sections and
663 * supersections.
664 */
665 static void __init create_mapping(struct map_desc *md)
666 {
667 unsigned long addr, length, end;
668 phys_addr_t phys;
669 const struct mem_type *type;
670 pgd_t *pgd;
671
672 if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) {
673 printk(KERN_WARNING "BUG: not creating mapping for 0x%08llx"
674 " at 0x%08lx in user region\n",
675 (long long)__pfn_to_phys((u64)md->pfn), md->virtual);
676 return;
677 }
678
679 if ((md->type == MT_DEVICE || md->type == MT_ROM) &&
680 md->virtual >= PAGE_OFFSET && md->virtual < VMALLOC_END) {
681 printk(KERN_WARNING "BUG: mapping for 0x%08llx"
682 " at 0x%08lx overlaps vmalloc space\n",
683 (long long)__pfn_to_phys((u64)md->pfn), md->virtual);
684 }
685
686 type = &mem_types[md->type];
687
688 /*
689 * Catch 36-bit addresses
690 */
691 if (md->pfn >= 0x100000) {
692 create_36bit_mapping(md, type);
693 return;
694 }
695
696 addr = md->virtual & PAGE_MASK;
697 phys = __pfn_to_phys(md->pfn);
698 length = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
699
700 if (type->prot_l1 == 0 && ((addr | phys | length) & ~SECTION_MASK)) {
701 printk(KERN_WARNING "BUG: map for 0x%08llx at 0x%08lx can not "
702 "be mapped using pages, ignoring.\n",
703 (long long)__pfn_to_phys(md->pfn), addr);
704 return;
705 }
706
707 pgd = pgd_offset_k(addr);
708 end = addr + length;
709 do {
710 unsigned long next = pgd_addr_end(addr, end);
711
712 alloc_init_pud(pgd, addr, next, phys, type);
713
714 phys += next - addr;
715 addr = next;
716 } while (pgd++, addr != end);
717 }
718
719 /*
720 * Create the architecture specific mappings
721 */
722 void __init iotable_init(struct map_desc *io_desc, int nr)
723 {
724 int i;
725
726 for (i = 0; i < nr; i++)
727 create_mapping(io_desc + i);
728 }
729
730 static void * __initdata vmalloc_min = (void *)(VMALLOC_END - SZ_128M);
731
732 /*
733 * vmalloc=size forces the vmalloc area to be exactly 'size'
734 * bytes. This can be used to increase (or decrease) the vmalloc
735 * area - the default is 128m.
736 */
737 static int __init early_vmalloc(char *arg)
738 {
739 unsigned long vmalloc_reserve = memparse(arg, NULL);
740
741 if (vmalloc_reserve < SZ_16M) {
742 vmalloc_reserve = SZ_16M;
743 printk(KERN_WARNING
744 "vmalloc area too small, limiting to %luMB\n",
745 vmalloc_reserve >> 20);
746 }
747
748 if (vmalloc_reserve > VMALLOC_END - (PAGE_OFFSET + SZ_32M)) {
749 vmalloc_reserve = VMALLOC_END - (PAGE_OFFSET + SZ_32M);
750 printk(KERN_WARNING
751 "vmalloc area is too big, limiting to %luMB\n",
752 vmalloc_reserve >> 20);
753 }
754
755 vmalloc_min = (void *)(VMALLOC_END - vmalloc_reserve);
756 return 0;
757 }
758 early_param("vmalloc", early_vmalloc);
759
760 static phys_addr_t lowmem_limit __initdata = 0;
761
762 void __init sanity_check_meminfo(void)
763 {
764 int i, j, highmem = 0;
765
766 for (i = 0, j = 0; i < meminfo.nr_banks; i++) {
767 struct membank *bank = &meminfo.bank[j];
768 *bank = meminfo.bank[i];
769
770 #ifdef CONFIG_HIGHMEM
771 if (__va(bank->start) >= vmalloc_min ||
772 __va(bank->start) < (void *)PAGE_OFFSET)
773 highmem = 1;
774
775 bank->highmem = highmem;
776
777 /*
778 * Split those memory banks which are partially overlapping
779 * the vmalloc area greatly simplifying things later.
780 */
781 if (__va(bank->start) < vmalloc_min &&
782 bank->size > vmalloc_min - __va(bank->start)) {
783 if (meminfo.nr_banks >= NR_BANKS) {
784 printk(KERN_CRIT "NR_BANKS too low, "
785 "ignoring high memory\n");
786 } else {
787 memmove(bank + 1, bank,
788 (meminfo.nr_banks - i) * sizeof(*bank));
789 meminfo.nr_banks++;
790 i++;
791 bank[1].size -= vmalloc_min - __va(bank->start);
792 bank[1].start = __pa(vmalloc_min - 1) + 1;
793 bank[1].highmem = highmem = 1;
794 j++;
795 }
796 bank->size = vmalloc_min - __va(bank->start);
797 }
798 #else
799 bank->highmem = highmem;
800
801 /*
802 * Check whether this memory bank would entirely overlap
803 * the vmalloc area.
804 */
805 if (__va(bank->start) >= vmalloc_min ||
806 __va(bank->start) < (void *)PAGE_OFFSET) {
807 printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx "
808 "(vmalloc region overlap).\n",
809 (unsigned long long)bank->start,
810 (unsigned long long)bank->start + bank->size - 1);
811 continue;
812 }
813
814 /*
815 * Check whether this memory bank would partially overlap
816 * the vmalloc area.
817 */
818 if (__va(bank->start + bank->size) > vmalloc_min ||
819 __va(bank->start + bank->size) < __va(bank->start)) {
820 unsigned long newsize = vmalloc_min - __va(bank->start);
821 printk(KERN_NOTICE "Truncating RAM at %.8llx-%.8llx "
822 "to -%.8llx (vmalloc region overlap).\n",
823 (unsigned long long)bank->start,
824 (unsigned long long)bank->start + bank->size - 1,
825 (unsigned long long)bank->start + newsize - 1);
826 bank->size = newsize;
827 }
828 #endif
829 if (!bank->highmem && bank->start + bank->size > lowmem_limit)
830 lowmem_limit = bank->start + bank->size;
831
832 j++;
833 }
834 #ifdef CONFIG_HIGHMEM
835 if (highmem) {
836 const char *reason = NULL;
837
838 if (cache_is_vipt_aliasing()) {
839 /*
840 * Interactions between kmap and other mappings
841 * make highmem support with aliasing VIPT caches
842 * rather difficult.
843 */
844 reason = "with VIPT aliasing cache";
845 }
846 if (reason) {
847 printk(KERN_CRIT "HIGHMEM is not supported %s, ignoring high memory\n",
848 reason);
849 while (j > 0 && meminfo.bank[j - 1].highmem)
850 j--;
851 }
852 }
853 #endif
854 meminfo.nr_banks = j;
855 memblock_set_current_limit(lowmem_limit);
856 }
857
858 static inline void prepare_page_table(void)
859 {
860 unsigned long addr;
861 phys_addr_t end;
862
863 /*
864 * Clear out all the mappings below the kernel image.
865 */
866 for (addr = 0; addr < MODULES_VADDR; addr += PMD_SIZE)
867 pmd_clear(pmd_off_k(addr));
868
869 #ifdef CONFIG_XIP_KERNEL
870 /* The XIP kernel is mapped in the module area -- skip over it */
871 addr = ((unsigned long)_etext + PMD_SIZE - 1) & PMD_MASK;
872 #endif
873 for ( ; addr < PAGE_OFFSET; addr += PMD_SIZE)
874 pmd_clear(pmd_off_k(addr));
875
876 /*
877 * Find the end of the first block of lowmem.
878 */
879 end = memblock.memory.regions[0].base + memblock.memory.regions[0].size;
880 if (end >= lowmem_limit)
881 end = lowmem_limit;
882
883 /*
884 * Clear out all the kernel space mappings, except for the first
885 * memory bank, up to the end of the vmalloc region.
886 */
887 for (addr = __phys_to_virt(end);
888 addr < VMALLOC_END; addr += PMD_SIZE)
889 pmd_clear(pmd_off_k(addr));
890 }
891
892 #define SWAPPER_PG_DIR_SIZE (PTRS_PER_PGD * sizeof(pgd_t))
893
894 /*
895 * Reserve the special regions of memory
896 */
897 void __init arm_mm_memblock_reserve(void)
898 {
899 /*
900 * Reserve the page tables. These are already in use,
901 * and can only be in node 0.
902 */
903 memblock_reserve(__pa(swapper_pg_dir), SWAPPER_PG_DIR_SIZE);
904
905 #ifdef CONFIG_SA1111
906 /*
907 * Because of the SA1111 DMA bug, we want to preserve our
908 * precious DMA-able memory...
909 */
910 memblock_reserve(PHYS_OFFSET, __pa(swapper_pg_dir) - PHYS_OFFSET);
911 #endif
912 }
913
914 /*
915 * Set up device the mappings. Since we clear out the page tables for all
916 * mappings above VMALLOC_END, we will remove any debug device mappings.
917 * This means you have to be careful how you debug this function, or any
918 * called function. This means you can't use any function or debugging
919 * method which may touch any device, otherwise the kernel _will_ crash.
920 */
921 static void __init devicemaps_init(struct machine_desc *mdesc)
922 {
923 struct map_desc map;
924 unsigned long addr;
925
926 /*
927 * Allocate the vector page early.
928 */
929 vectors_page = early_alloc(PAGE_SIZE);
930
931 for (addr = VMALLOC_END; addr; addr += PMD_SIZE)
932 pmd_clear(pmd_off_k(addr));
933
934 /*
935 * Map the kernel if it is XIP.
936 * It is always first in the modulearea.
937 */
938 #ifdef CONFIG_XIP_KERNEL
939 map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK);
940 map.virtual = MODULES_VADDR;
941 map.length = ((unsigned long)_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK;
942 map.type = MT_ROM;
943 create_mapping(&map);
944 #endif
945
946 /*
947 * Map the cache flushing regions.
948 */
949 #ifdef FLUSH_BASE
950 map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS);
951 map.virtual = FLUSH_BASE;
952 map.length = SZ_1M;
953 map.type = MT_CACHECLEAN;
954 create_mapping(&map);
955 #endif
956 #ifdef FLUSH_BASE_MINICACHE
957 map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M);
958 map.virtual = FLUSH_BASE_MINICACHE;
959 map.length = SZ_1M;
960 map.type = MT_MINICLEAN;
961 create_mapping(&map);
962 #endif
963
964 /*
965 * Create a mapping for the machine vectors at the high-vectors
966 * location (0xffff0000). If we aren't using high-vectors, also
967 * create a mapping at the low-vectors virtual address.
968 */
969 map.pfn = __phys_to_pfn(virt_to_phys(vectors_page));
970 map.virtual = 0xffff0000;
971 map.length = PAGE_SIZE;
972 map.type = MT_HIGH_VECTORS;
973 create_mapping(&map);
974
975 if (!vectors_high()) {
976 map.virtual = 0;
977 map.type = MT_LOW_VECTORS;
978 create_mapping(&map);
979 }
980
981 /*
982 * Ask the machine support to map in the statically mapped devices.
983 */
984 if (mdesc->map_io)
985 mdesc->map_io();
986
987 /*
988 * Finally flush the caches and tlb to ensure that we're in a
989 * consistent state wrt the writebuffer. This also ensures that
990 * any write-allocated cache lines in the vector page are written
991 * back. After this point, we can start to touch devices again.
992 */
993 local_flush_tlb_all();
994 flush_cache_all();
995 }
996
997 static void __init kmap_init(void)
998 {
999 #ifdef CONFIG_HIGHMEM
1000 pkmap_page_table = early_pte_alloc(pmd_off_k(PKMAP_BASE),
1001 PKMAP_BASE, _PAGE_KERNEL_TABLE);
1002 #endif
1003 }
1004
1005 static void __init map_lowmem(void)
1006 {
1007 struct memblock_region *reg;
1008
1009 /* Map all the lowmem memory banks. */
1010 for_each_memblock(memory, reg) {
1011 phys_addr_t start = reg->base;
1012 phys_addr_t end = start + reg->size;
1013 struct map_desc map;
1014
1015 if (end > lowmem_limit)
1016 end = lowmem_limit;
1017 if (start >= end)
1018 break;
1019
1020 map.pfn = __phys_to_pfn(start);
1021 map.virtual = __phys_to_virt(start);
1022 map.length = end - start;
1023 map.type = MT_MEMORY;
1024
1025 create_mapping(&map);
1026 }
1027 }
1028
1029 /*
1030 * paging_init() sets up the page tables, initialises the zone memory
1031 * maps, and sets up the zero page, bad page and bad page tables.
1032 */
1033 void __init paging_init(struct machine_desc *mdesc)
1034 {
1035 void *zero_page;
1036
1037 memblock_set_current_limit(lowmem_limit);
1038
1039 build_mem_type_table();
1040 prepare_page_table();
1041 map_lowmem();
1042 devicemaps_init(mdesc);
1043 kmap_init();
1044
1045 top_pmd = pmd_off_k(0xffff0000);
1046
1047 /* allocate the zero page. */
1048 zero_page = early_alloc(PAGE_SIZE);
1049
1050 bootmem_init();
1051
1052 empty_zero_page = virt_to_page(zero_page);
1053 __flush_dcache_page(NULL, empty_zero_page);
1054 }
Linux Btrfs Development