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[ARM] 3998/1: VR1000: LED platform devices
[linux-2.6-block.git] / arch / arm / mm / mmu.c
CommitLineData
d111e8f9
RK		 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 */
ae8f1541 10#include <linux/module.h>
d111e8f9
RK		 11#include <linux/kernel.h>
12#include <linux/errno.h>
13#include <linux/init.h>
14#include <linux/bootmem.h>
15#include <linux/mman.h>
16#include <linux/nodemask.h>
17
18#include <asm/mach-types.h>
19#include <asm/setup.h>
20#include <asm/sizes.h>
21#include <asm/tlb.h>
22
23#include <asm/mach/arch.h>
24#include <asm/mach/map.h>
25
26#include "mm.h"
27
28DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
29
6ae5a6ef 30extern void _stext, _etext, __data_start, _end;
d111e8f9
RK		 31extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
32
33/*
34 * empty_zero_page is a special page that is used for
35 * zero-initialized data and COW.
36 */
37struct page *empty_zero_page;
38
39/*
40 * The pmd table for the upper-most set of pages.
41 */
42pmd_t *top_pmd;
43
ae8f1541
RK		 44#define CPOLICY_UNCACHED 0
45#define CPOLICY_BUFFERED 1
46#define CPOLICY_WRITETHROUGH 2
47#define CPOLICY_WRITEBACK 3
48#define CPOLICY_WRITEALLOC 4
49
50static unsigned int cachepolicy __initdata = CPOLICY_WRITEBACK;
51static unsigned int ecc_mask __initdata = 0;
52pgprot_t pgprot_kernel;
53
54EXPORT_SYMBOL(pgprot_kernel);
55
56struct cachepolicy {
57 const char policy[16];
58 unsigned int cr_mask;
59 unsigned int pmd;
60 unsigned int pte;
61};
62
63static struct cachepolicy cache_policies[] __initdata = {
64 {
65 .policy = "uncached",
66 .cr_mask = CR_W|CR_C,
67 .pmd = PMD_SECT_UNCACHED,
68 .pte = 0,
69 }, {
70 .policy = "buffered",
71 .cr_mask = CR_C,
72 .pmd = PMD_SECT_BUFFERED,
73 .pte = PTE_BUFFERABLE,
74 }, {
75 .policy = "writethrough",
76 .cr_mask = 0,
77 .pmd = PMD_SECT_WT,
78 .pte = PTE_CACHEABLE,
79 }, {
80 .policy = "writeback",
81 .cr_mask = 0,
82 .pmd = PMD_SECT_WB,
83 .pte = PTE_BUFFERABLE|PTE_CACHEABLE,
84 }, {
85 .policy = "writealloc",
86 .cr_mask = 0,
87 .pmd = PMD_SECT_WBWA,
88 .pte = PTE_BUFFERABLE|PTE_CACHEABLE,
89 }
90};
91
92/*
93 * These are useful for identifing cache coherency
94 * problems by allowing the cache or the cache and
95 * writebuffer to be turned off. (Note: the write
96 * buffer should not be on and the cache off).
97 */
98static void __init early_cachepolicy(char **p)
99{
100 int i;
101
102 for (i = 0; i < ARRAY_SIZE(cache_policies); i++) {
103 int len = strlen(cache_policies[i].policy);
104
105 if (memcmp(*p, cache_policies[i].policy, len) == 0) {
106 cachepolicy = i;
107 cr_alignment &= ~cache_policies[i].cr_mask;
108 cr_no_alignment &= ~cache_policies[i].cr_mask;
109 *p += len;
110 break;
111 }
112 }
113 if (i == ARRAY_SIZE(cache_policies))
114 printk(KERN_ERR "ERROR: unknown or unsupported cache policy\n");
115 flush_cache_all();
116 set_cr(cr_alignment);
117}
118__early_param("cachepolicy=", early_cachepolicy);
119
120static void __init early_nocache(char **__unused)
121{
122 char *p = "buffered";
123 printk(KERN_WARNING "nocache is deprecated; use cachepolicy=%s\n", p);
124 early_cachepolicy(&p);
125}
126__early_param("nocache", early_nocache);
127
128static void __init early_nowrite(char **__unused)
129{
130 char *p = "uncached";
131 printk(KERN_WARNING "nowb is deprecated; use cachepolicy=%s\n", p);
132 early_cachepolicy(&p);
133}
134__early_param("nowb", early_nowrite);
135
136static void __init early_ecc(char **p)
137{
138 if (memcmp(*p, "on", 2) == 0) {
139 ecc_mask = PMD_PROTECTION;
140 *p += 2;
141 } else if (memcmp(*p, "off", 3) == 0) {
142 ecc_mask = 0;
143 *p += 3;
144 }
145}
146__early_param("ecc=", early_ecc);
147
148static int __init noalign_setup(char *__unused)
149{
150 cr_alignment &= ~CR_A;
151 cr_no_alignment &= ~CR_A;
152 set_cr(cr_alignment);
153 return 1;
154}
155__setup("noalign", noalign_setup);
156
157struct mem_types {
158 unsigned int prot_pte;
159 unsigned int prot_l1;
160 unsigned int prot_sect;
161 unsigned int domain;
162};
163
164static struct mem_types mem_types[] __initdata = {
165 [MT_DEVICE] = {
166 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
167 L_PTE_WRITE,
168 .prot_l1 = PMD_TYPE_TABLE,
169 .prot_sect = PMD_TYPE_SECT | PMD_BIT4 | PMD_SECT_UNCACHED |
170 PMD_SECT_AP_WRITE,
171 .domain = DOMAIN_IO,
172 },
173 [MT_CACHECLEAN] = {
174 .prot_sect = PMD_TYPE_SECT | PMD_BIT4,
175 .domain = DOMAIN_KERNEL,
176 },
177 [MT_MINICLEAN] = {
178 .prot_sect = PMD_TYPE_SECT | PMD_BIT4 | PMD_SECT_MINICACHE,
179 .domain = DOMAIN_KERNEL,
180 },
181 [MT_LOW_VECTORS] = {
182 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
183 L_PTE_EXEC,
184 .prot_l1 = PMD_TYPE_TABLE,
185 .domain = DOMAIN_USER,
186 },
187 [MT_HIGH_VECTORS] = {
188 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
189 L_PTE_USER | L_PTE_EXEC,
190 .prot_l1 = PMD_TYPE_TABLE,
191 .domain = DOMAIN_USER,
192 },
193 [MT_MEMORY] = {
194 .prot_sect = PMD_TYPE_SECT | PMD_BIT4 | PMD_SECT_AP_WRITE,
195 .domain = DOMAIN_KERNEL,
196 },
197 [MT_ROM] = {
198 .prot_sect = PMD_TYPE_SECT | PMD_BIT4,
199 .domain = DOMAIN_KERNEL,
200 },
201 [MT_IXP2000_DEVICE] = { /* IXP2400 requires XCB=101 for on-chip I/O */
202 .prot_pte = L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_DIRTY |
203 L_PTE_WRITE,
204 .prot_l1 = PMD_TYPE_TABLE,
205 .prot_sect = PMD_TYPE_SECT | PMD_BIT4 | PMD_SECT_UNCACHED |
206 PMD_SECT_AP_WRITE | PMD_SECT_BUFFERABLE |
207 PMD_SECT_TEX(1),
208 .domain = DOMAIN_IO,
209 },
210 [MT_NONSHARED_DEVICE] = {
211 .prot_l1 = PMD_TYPE_TABLE,
212 .prot_sect = PMD_TYPE_SECT | PMD_BIT4 | PMD_SECT_NONSHARED_DEV |
213 PMD_SECT_AP_WRITE,
214 .domain = DOMAIN_IO,
215 }
216};
217
218/*
219 * Adjust the PMD section entries according to the CPU in use.
220 */
221static void __init build_mem_type_table(void)
222{
223 struct cachepolicy *cp;
224 unsigned int cr = get_cr();
225 unsigned int user_pgprot, kern_pgprot;
226 int cpu_arch = cpu_architecture();
227 int i;
228
229#if defined(CONFIG_CPU_DCACHE_DISABLE)
230 if (cachepolicy > CPOLICY_BUFFERED)
231 cachepolicy = CPOLICY_BUFFERED;
232#elif defined(CONFIG_CPU_DCACHE_WRITETHROUGH)
233 if (cachepolicy > CPOLICY_WRITETHROUGH)
234 cachepolicy = CPOLICY_WRITETHROUGH;
235#endif
236 if (cpu_arch < CPU_ARCH_ARMv5) {
237 if (cachepolicy >= CPOLICY_WRITEALLOC)
238 cachepolicy = CPOLICY_WRITEBACK;
239 ecc_mask = 0;
240 }
241
242 /*
243 * Xscale must not have PMD bit 4 set for section mappings.
244 */
245 if (cpu_is_xscale())
246 for (i = 0; i < ARRAY_SIZE(mem_types); i++)
247 mem_types[i].prot_sect &= ~PMD_BIT4;
248
249 /*
250 * ARMv5 and lower, excluding Xscale, bit 4 must be set for
251 * page tables.
252 */
253 if (cpu_arch < CPU_ARCH_ARMv6 && !cpu_is_xscale())
254 for (i = 0; i < ARRAY_SIZE(mem_types); i++)
255 if (mem_types[i].prot_l1)
256 mem_types[i].prot_l1 |= PMD_BIT4;
257
258 cp = &cache_policies[cachepolicy];
259 kern_pgprot = user_pgprot = cp->pte;
260
261 /*
262 * Enable CPU-specific coherency if supported.
263 * (Only available on XSC3 at the moment.)
264 */
265 if (arch_is_coherent()) {
266 if (cpu_is_xsc3()) {
267 mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
0e5fdca7 268 mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED;
ae8f1541
RK		 269 }
270 }
271
272 /*
273 * ARMv6 and above have extended page tables.
274 */
275 if (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP)) {
276 /*
277 * bit 4 becomes XN which we must clear for the
278 * kernel memory mapping.
279 */
280 mem_types[MT_MEMORY].prot_sect &= ~PMD_SECT_XN;
281 mem_types[MT_ROM].prot_sect &= ~PMD_SECT_XN;
282
283 /*
284 * Mark cache clean areas and XIP ROM read only
285 * from SVC mode and no access from userspace.
286 */
287 mem_types[MT_ROM].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
288 mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
289 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
290
291 /*
292 * Mark the device area as "shared device"
293 */
294 mem_types[MT_DEVICE].prot_pte |= L_PTE_BUFFERABLE;
295 mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED;
296
297 /*
298 * User pages need to be mapped with the ASID
299 * (iow, non-global)
300 */
301 user_pgprot |= L_PTE_ASID;
302
303#ifdef CONFIG_SMP
304 /*
305 * Mark memory with the "shared" attribute for SMP systems
306 */
307 user_pgprot |= L_PTE_SHARED;
308 kern_pgprot |= L_PTE_SHARED;
309 mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
310#endif
311 }
312
313 for (i = 0; i < 16; i++) {
314 unsigned long v = pgprot_val(protection_map[i]);
315 v = (v & ~(L_PTE_BUFFERABLE|L_PTE_CACHEABLE)) | user_pgprot;
316 protection_map[i] = __pgprot(v);
317 }
318
319 mem_types[MT_LOW_VECTORS].prot_pte |= kern_pgprot;
320 mem_types[MT_HIGH_VECTORS].prot_pte |= kern_pgprot;
321
322 if (cpu_arch >= CPU_ARCH_ARMv5) {
323#ifndef CONFIG_SMP
324 /*
325 * Only use write-through for non-SMP systems
326 */
327 mem_types[MT_LOW_VECTORS].prot_pte &= ~L_PTE_BUFFERABLE;
328 mem_types[MT_HIGH_VECTORS].prot_pte &= ~L_PTE_BUFFERABLE;
329#endif
330 } else {
331 mem_types[MT_MINICLEAN].prot_sect &= ~PMD_SECT_TEX(1);
332 }
333
334 pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |
335 L_PTE_DIRTY | L_PTE_WRITE |
336 L_PTE_EXEC | kern_pgprot);
337
338 mem_types[MT_LOW_VECTORS].prot_l1 |= ecc_mask;
339 mem_types[MT_HIGH_VECTORS].prot_l1 |= ecc_mask;
340 mem_types[MT_MEMORY].prot_sect |= ecc_mask | cp->pmd;
341 mem_types[MT_ROM].prot_sect |= cp->pmd;
342
343 switch (cp->pmd) {
344 case PMD_SECT_WT:
345 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WT;
346 break;
347 case PMD_SECT_WB:
348 case PMD_SECT_WBWA:
349 mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_WB;
350 break;
351 }
352 printk("Memory policy: ECC %sabled, Data cache %s\n",
353 ecc_mask ? "en" : "dis", cp->policy);
354}
355
356#define vectors_base() (vectors_high() ? 0xffff0000 : 0)
357
358/*
359 * Create a SECTION PGD between VIRT and PHYS in domain
360 * DOMAIN with protection PROT. This operates on half-
361 * pgdir entry increments.
362 */
363static inline void
364alloc_init_section(unsigned long virt, unsigned long phys, int prot)
365{
366 pmd_t *pmdp = pmd_off_k(virt);
367
368 if (virt & (1 << 20))
369 pmdp++;
370
371 *pmdp = __pmd(phys | prot);
372 flush_pmd_entry(pmdp);
373}
374
375/*
376 * Create a SUPER SECTION PGD between VIRT and PHYS with protection PROT
377 */
378static inline void
379alloc_init_supersection(unsigned long virt, unsigned long phys, int prot)
380{
381 int i;
382
383 for (i = 0; i < 16; i += 1) {
384 alloc_init_section(virt, phys, prot | PMD_SECT_SUPER);
385
386 virt += (PGDIR_SIZE / 2);
387 }
388}
389
390/*
391 * Add a PAGE mapping between VIRT and PHYS in domain
392 * DOMAIN with protection PROT. Note that due to the
393 * way we map the PTEs, we must allocate two PTE_SIZE'd
394 * blocks - one for the Linux pte table, and one for
395 * the hardware pte table.
396 */
397static inline void
398alloc_init_page(unsigned long virt, unsigned long phys, unsigned int prot_l1, pgprot_t prot)
399{
400 pmd_t *pmdp = pmd_off_k(virt);
401 pte_t *ptep;
402
403 if (pmd_none(*pmdp)) {
404 ptep = alloc_bootmem_low_pages(2 * PTRS_PER_PTE *
405 sizeof(pte_t));
406
407 __pmd_populate(pmdp, __pa(ptep) | prot_l1);
408 }
409 ptep = pte_offset_kernel(pmdp, virt);
410
411 set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot));
412}
413
414/*
415 * Create the page directory entries and any necessary
416 * page tables for the mapping specified by `md'. We
417 * are able to cope here with varying sizes and address
418 * offsets, and we take full advantage of sections and
419 * supersections.
420 */
421void __init create_mapping(struct map_desc *md)
422{
423 unsigned long virt, length;
424 int prot_sect, prot_l1, domain;
425 pgprot_t prot_pte;
426 unsigned long off = (u32)__pfn_to_phys(md->pfn);
427
428 if (md->virtual != vectors_base() && md->virtual < TASK_SIZE) {
429 printk(KERN_WARNING "BUG: not creating mapping for "
430 "0x%08llx at 0x%08lx in user region\n",
431 __pfn_to_phys((u64)md->pfn), md->virtual);
432 return;
433 }
434
435 if ((md->type == MT_DEVICE || md->type == MT_ROM) &&
436 md->virtual >= PAGE_OFFSET && md->virtual < VMALLOC_END) {
437 printk(KERN_WARNING "BUG: mapping for 0x%08llx at 0x%08lx "
438 "overlaps vmalloc space\n",
439 __pfn_to_phys((u64)md->pfn), md->virtual);
440 }
441
442 domain = mem_types[md->type].domain;
443 prot_pte = __pgprot(mem_types[md->type].prot_pte);
444 prot_l1 = mem_types[md->type].prot_l1 | PMD_DOMAIN(domain);
445 prot_sect = mem_types[md->type].prot_sect | PMD_DOMAIN(domain);
446
447 /*
448 * Catch 36-bit addresses
449 */
450 if(md->pfn >= 0x100000) {
451 if(domain) {
452 printk(KERN_ERR "MM: invalid domain in supersection "
453 "mapping for 0x%08llx at 0x%08lx\n",
454 __pfn_to_phys((u64)md->pfn), md->virtual);
455 return;
456 }
457 if((md->virtual | md->length | __pfn_to_phys(md->pfn))
458 & ~SUPERSECTION_MASK) {
459 printk(KERN_ERR "MM: cannot create mapping for "
460 "0x%08llx at 0x%08lx invalid alignment\n",
461 __pfn_to_phys((u64)md->pfn), md->virtual);
462 return;
463 }
464
465 /*
466 * Shift bits [35:32] of address into bits [23:20] of PMD
467 * (See ARMv6 spec).
468 */
469 off |= (((md->pfn >> (32 - PAGE_SHIFT)) & 0xF) << 20);
470 }
471
472 virt = md->virtual;
473 off -= virt;
474 length = md->length;
475
476 if (mem_types[md->type].prot_l1 == 0 &&
477 (virt & 0xfffff || (virt + off) & 0xfffff || (virt + length) & 0xfffff)) {
478 printk(KERN_WARNING "BUG: map for 0x%08lx at 0x%08lx can not "
479 "be mapped using pages, ignoring.\n",
480 __pfn_to_phys(md->pfn), md->virtual);
481 return;
482 }
483
484 while ((virt & 0xfffff || (virt + off) & 0xfffff) && length >= PAGE_SIZE) {
485 alloc_init_page(virt, virt + off, prot_l1, prot_pte);
486
487 virt += PAGE_SIZE;
488 length -= PAGE_SIZE;
489 }
490
491 /* N.B. ARMv6 supersections are only defined to work with domain 0.
492 * Since domain assignments can in fact be arbitrary, the
493 * 'domain == 0' check below is required to insure that ARMv6
494 * supersections are only allocated for domain 0 regardless
495 * of the actual domain assignments in use.
496 */
497 if ((cpu_architecture() >= CPU_ARCH_ARMv6 || cpu_is_xsc3())
498 && domain == 0) {
499 /*
500 * Align to supersection boundary if !high pages.
501 * High pages have already been checked for proper
502 * alignment above and they will fail the SUPSERSECTION_MASK
503 * check because of the way the address is encoded into
504 * offset.
505 */
506 if (md->pfn <= 0x100000) {
507 while ((virt & ~SUPERSECTION_MASK ||
508 (virt + off) & ~SUPERSECTION_MASK) &&
509 length >= (PGDIR_SIZE / 2)) {
510 alloc_init_section(virt, virt + off, prot_sect);
511
512 virt += (PGDIR_SIZE / 2);
513 length -= (PGDIR_SIZE / 2);
514 }
515 }
516
517 while (length >= SUPERSECTION_SIZE) {
518 alloc_init_supersection(virt, virt + off, prot_sect);
519
520 virt += SUPERSECTION_SIZE;
521 length -= SUPERSECTION_SIZE;
522 }
523 }
524
525 /*
526 * A section mapping covers half a "pgdir" entry.
527 */
528 while (length >= (PGDIR_SIZE / 2)) {
529 alloc_init_section(virt, virt + off, prot_sect);
530
531 virt += (PGDIR_SIZE / 2);
532 length -= (PGDIR_SIZE / 2);
533 }
534
535 while (length >= PAGE_SIZE) {
536 alloc_init_page(virt, virt + off, prot_l1, prot_pte);
537
538 virt += PAGE_SIZE;
539 length -= PAGE_SIZE;
540 }
541}
542
543/*
544 * Create the architecture specific mappings
545 */
546void __init iotable_init(struct map_desc *io_desc, int nr)
547{
548 int i;
549
550 for (i = 0; i < nr; i++)
551 create_mapping(io_desc + i);
552}
553
d111e8f9
RK		 554static inline void prepare_page_table(struct meminfo *mi)
555{
556 unsigned long addr;
557
558 /*
559 * Clear out all the mappings below the kernel image.
560 */
561 for (addr = 0; addr < MODULE_START; addr += PGDIR_SIZE)
562 pmd_clear(pmd_off_k(addr));
563
564#ifdef CONFIG_XIP_KERNEL
565 /* The XIP kernel is mapped in the module area -- skip over it */
566 addr = ((unsigned long)&_etext + PGDIR_SIZE - 1) & PGDIR_MASK;
567#endif
568 for ( ; addr < PAGE_OFFSET; addr += PGDIR_SIZE)
569 pmd_clear(pmd_off_k(addr));
570
571 /*
572 * Clear out all the kernel space mappings, except for the first
573 * memory bank, up to the end of the vmalloc region.
574 */
575 for (addr = __phys_to_virt(mi->bank[0].start + mi->bank[0].size);
576 addr < VMALLOC_END; addr += PGDIR_SIZE)
577 pmd_clear(pmd_off_k(addr));
578}
579
580/*
581 * Reserve the various regions of node 0
582 */
583void __init reserve_node_zero(pg_data_t *pgdat)
584{
585 unsigned long res_size = 0;
586
587 /*
588 * Register the kernel text and data with bootmem.
589 * Note that this can only be in node 0.
590 */
591#ifdef CONFIG_XIP_KERNEL
592 reserve_bootmem_node(pgdat, __pa(&__data_start), &_end - &__data_start);
593#else
594 reserve_bootmem_node(pgdat, __pa(&_stext), &_end - &_stext);
595#endif
596
597 /*
598 * Reserve the page tables. These are already in use,
599 * and can only be in node 0.
600 */
601 reserve_bootmem_node(pgdat, __pa(swapper_pg_dir),
602 PTRS_PER_PGD * sizeof(pgd_t));
603
604 /*
605 * Hmm... This should go elsewhere, but we really really need to
606 * stop things allocating the low memory; ideally we need a better
607 * implementation of GFP_DMA which does not assume that DMA-able
608 * memory starts at zero.
609 */
610 if (machine_is_integrator() || machine_is_cintegrator())
611 res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;
612
613 /*
614 * These should likewise go elsewhere. They pre-reserve the
615 * screen memory region at the start of main system memory.
616 */
617 if (machine_is_edb7211())
618 res_size = 0x00020000;
619 if (machine_is_p720t())
620 res_size = 0x00014000;
621
9073341c
BD		 622 if (machine_is_h1940()) {
623 reserve_bootmem_node(pgdat, 0x30003000, 0x1000);
624 reserve_bootmem_node(pgdat, 0x30081000, 0x1000);
625 }
626
d111e8f9
RK		 627#ifdef CONFIG_SA1111
628 /*
629 * Because of the SA1111 DMA bug, we want to preserve our
630 * precious DMA-able memory...
631 */
632 res_size = __pa(swapper_pg_dir) - PHYS_OFFSET;
633#endif
634 if (res_size)
635 reserve_bootmem_node(pgdat, PHYS_OFFSET, res_size);
636}
637
638/*
639 * Set up device the mappings. Since we clear out the page tables for all
640 * mappings above VMALLOC_END, we will remove any debug device mappings.
641 * This means you have to be careful how you debug this function, or any
642 * called function. This means you can't use any function or debugging
643 * method which may touch any device, otherwise the kernel _will_ crash.
644 */
645static void __init devicemaps_init(struct machine_desc *mdesc)
646{
647 struct map_desc map;
648 unsigned long addr;
649 void *vectors;
650
651 /*
652 * Allocate the vector page early.
653 */
654 vectors = alloc_bootmem_low_pages(PAGE_SIZE);
655 BUG_ON(!vectors);
656
657 for (addr = VMALLOC_END; addr; addr += PGDIR_SIZE)
658 pmd_clear(pmd_off_k(addr));
659
660 /*
661 * Map the kernel if it is XIP.
662 * It is always first in the modulearea.
663 */
664#ifdef CONFIG_XIP_KERNEL
665 map.pfn = __phys_to_pfn(CONFIG_XIP_PHYS_ADDR & SECTION_MASK);
666 map.virtual = MODULE_START;
667 map.length = ((unsigned long)&_etext - map.virtual + ~SECTION_MASK) & SECTION_MASK;
668 map.type = MT_ROM;
669 create_mapping(&map);
670#endif
671
672 /*
673 * Map the cache flushing regions.
674 */
675#ifdef FLUSH_BASE
676 map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS);
677 map.virtual = FLUSH_BASE;
678 map.length = SZ_1M;
679 map.type = MT_CACHECLEAN;
680 create_mapping(&map);
681#endif
682#ifdef FLUSH_BASE_MINICACHE
683 map.pfn = __phys_to_pfn(FLUSH_BASE_PHYS + SZ_1M);
684 map.virtual = FLUSH_BASE_MINICACHE;
685 map.length = SZ_1M;
686 map.type = MT_MINICLEAN;
687 create_mapping(&map);
688#endif
689
690 /*
691 * Create a mapping for the machine vectors at the high-vectors
692 * location (0xffff0000). If we aren't using high-vectors, also
693 * create a mapping at the low-vectors virtual address.
694 */
695 map.pfn = __phys_to_pfn(virt_to_phys(vectors));
696 map.virtual = 0xffff0000;
697 map.length = PAGE_SIZE;
698 map.type = MT_HIGH_VECTORS;
699 create_mapping(&map);
700
701 if (!vectors_high()) {
702 map.virtual = 0;
703 map.type = MT_LOW_VECTORS;
704 create_mapping(&map);
705 }
706
707 /*
708 * Ask the machine support to map in the statically mapped devices.
709 */
710 if (mdesc->map_io)
711 mdesc->map_io();
712
713 /*
714 * Finally flush the caches and tlb to ensure that we're in a
715 * consistent state wrt the writebuffer. This also ensures that
716 * any write-allocated cache lines in the vector page are written
717 * back. After this point, we can start to touch devices again.
718 */
719 local_flush_tlb_all();
720 flush_cache_all();
721}
722
723/*
724 * paging_init() sets up the page tables, initialises the zone memory
725 * maps, and sets up the zero page, bad page and bad page tables.
726 */
727void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)
728{
729 void *zero_page;
730
731 build_mem_type_table();
732 prepare_page_table(mi);
733 bootmem_init(mi);
734 devicemaps_init(mdesc);
735
736 top_pmd = pmd_off_k(0xffff0000);
737
738 /*
739 * allocate the zero page. Note that we count on this going ok.
740 */
741 zero_page = alloc_bootmem_low_pages(PAGE_SIZE);
742 memzero(zero_page, PAGE_SIZE);
743 empty_zero_page = virt_to_page(zero_page);
744 flush_dcache_page(empty_zero_page);
745}
ae8f1541
RK		 746
747/*
748 * In order to soft-boot, we need to insert a 1:1 mapping in place of
749 * the user-mode pages. This will then ensure that we have predictable
750 * results when turning the mmu off
751 */
752void setup_mm_for_reboot(char mode)
753{
754 unsigned long base_pmdval;
755 pgd_t *pgd;
756 int i;
757
758 if (current->mm && current->mm->pgd)
759 pgd = current->mm->pgd;
760 else
761 pgd = init_mm.pgd;
762
763 base_pmdval = PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | PMD_TYPE_SECT;
764 if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
765 base_pmdval |= PMD_BIT4;
766
767 for (i = 0; i < FIRST_USER_PGD_NR + USER_PTRS_PER_PGD; i++, pgd++) {
768 unsigned long pmdval = (i << PGDIR_SHIFT) | base_pmdval;
769 pmd_t *pmd;
770
771 pmd = pmd_off(pgd, i << PGDIR_SHIFT);
772 pmd[0] = __pmd(pmdval);
773 pmd[1] = __pmd(pmdval + (1 << (PGDIR_SHIFT - 1)));
774 flush_pmd_entry(pmd);
775 }
776}
Linux 6.x block layer and io_uring tree(s)