pstore/ram: add Device Tree bindings
[deliverable/linux.git] / arch / powerpc / mm / pgtable_32.c
CommitLineData
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1/*
2 * This file contains the routines setting up the linux page tables.
3 * -- paulus
4 *
5 * Derived from arch/ppc/mm/init.c:
6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
7 *
8 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
9 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
10 * Copyright (C) 1996 Paul Mackerras
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11 *
12 * Derived from "arch/i386/mm/init.c"
13 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
19 *
20 */
21
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22#include <linux/kernel.h>
23#include <linux/module.h>
24#include <linux/types.h>
25#include <linux/mm.h>
26#include <linux/vmalloc.h>
27#include <linux/init.h>
28#include <linux/highmem.h>
95f72d1e 29#include <linux/memblock.h>
5a0e3ad6 30#include <linux/slab.h>
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31
32#include <asm/pgtable.h>
33#include <asm/pgalloc.h>
2c419bde 34#include <asm/fixmap.h>
14cf11af 35#include <asm/io.h>
ae3a197e 36#include <asm/setup.h>
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37
38#include "mmu_decl.h"
39
14cf11af 40unsigned long ioremap_bot;
920573bd 41EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */
14cf11af 42
060ef9d8 43extern char etext[], _stext[], _sinittext[], _einittext[];
14cf11af 44
ca9153a3 45#define PGDIR_ORDER (32 + PGD_T_LOG2 - PGDIR_SHIFT)
14cf11af 46
ce67f5d0
LC
47#ifndef CONFIG_PPC_4K_PAGES
48static struct kmem_cache *pgtable_cache;
49
50void pgtable_cache_init(void)
51{
52 pgtable_cache = kmem_cache_create("PGDIR cache", 1 << PGDIR_ORDER,
53 1 << PGDIR_ORDER, 0, NULL);
54 if (pgtable_cache == NULL)
55 panic("Couldn't allocate pgtable caches");
56}
57#endif
58
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59pgd_t *pgd_alloc(struct mm_struct *mm)
60{
61 pgd_t *ret;
62
ca9153a3
IY
63 /* pgdir take page or two with 4K pages and a page fraction otherwise */
64#ifndef CONFIG_PPC_4K_PAGES
ce67f5d0 65 ret = kmem_cache_alloc(pgtable_cache, GFP_KERNEL | __GFP_ZERO);
ca9153a3
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66#else
67 ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO,
68 PGDIR_ORDER - PAGE_SHIFT);
69#endif
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70 return ret;
71}
72
5e541973 73void pgd_free(struct mm_struct *mm, pgd_t *pgd)
14cf11af 74{
ca9153a3 75#ifndef CONFIG_PPC_4K_PAGES
ce67f5d0 76 kmem_cache_free(pgtable_cache, (void *)pgd);
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77#else
78 free_pages((unsigned long)pgd, PGDIR_ORDER - PAGE_SHIFT);
79#endif
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80}
81
f1aed924 82__init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address)
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83{
84 pte_t *pte;
14cf11af 85
f691fa10 86 if (slab_is_available()) {
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87 pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
88 } else {
10239733 89 pte = __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE));
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90 if (pte)
91 clear_page(pte);
92 }
93 return pte;
94}
95
2f569afd 96pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address)
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97{
98 struct page *ptepage;
99
2f569afd 100 gfp_t flags = GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO;
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101
102 ptepage = alloc_pages(flags, 0);
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103 if (!ptepage)
104 return NULL;
4f804943
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105 if (!pgtable_page_ctor(ptepage)) {
106 __free_page(ptepage);
107 return NULL;
108 }
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109 return ptepage;
110}
111
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112void __iomem *
113ioremap(phys_addr_t addr, unsigned long size)
114{
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BH
115 return __ioremap_caller(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED,
116 __builtin_return_address(0));
14cf11af 117}
920573bd 118EXPORT_SYMBOL(ioremap);
14cf11af 119
be135f40
AB
120void __iomem *
121ioremap_wc(phys_addr_t addr, unsigned long size)
122{
123 return __ioremap_caller(addr, size, _PAGE_NO_CACHE,
124 __builtin_return_address(0));
125}
126EXPORT_SYMBOL(ioremap_wc);
127
68a64357 128void __iomem *
40f1ce7f 129ioremap_prot(phys_addr_t addr, unsigned long size, unsigned long flags)
68a64357 130{
a1f242ff 131 /* writeable implies dirty for kernel addresses */
a7b9f671 132 if ((flags & (_PAGE_RW | _PAGE_RO)) != _PAGE_RO)
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BH
133 flags |= _PAGE_DIRTY | _PAGE_HWWRITE;
134
135 /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */
ea3cc330 136 flags &= ~(_PAGE_USER | _PAGE_EXEC);
a1f242ff 137
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138#ifdef _PAGE_BAP_SR
139 /* _PAGE_USER contains _PAGE_BAP_SR on BookE using the new PTE format
140 * which means that we just cleared supervisor access... oops ;-) This
141 * restores it
142 */
143 flags |= _PAGE_BAP_SR;
144#endif
145
1cdab55d 146 return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
68a64357 147}
40f1ce7f 148EXPORT_SYMBOL(ioremap_prot);
68a64357 149
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150void __iomem *
151__ioremap(phys_addr_t addr, unsigned long size, unsigned long flags)
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BH
152{
153 return __ioremap_caller(addr, size, flags, __builtin_return_address(0));
154}
155
156void __iomem *
157__ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags,
158 void *caller)
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159{
160 unsigned long v, i;
161 phys_addr_t p;
162 int err;
163
a1f242ff
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164 /* Make sure we have the base flags */
165 if ((flags & _PAGE_PRESENT) == 0)
4f9c53c8 166 flags |= pgprot_val(PAGE_KERNEL);
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167
168 /* Non-cacheable page cannot be coherent */
169 if (flags & _PAGE_NO_CACHE)
170 flags &= ~_PAGE_COHERENT;
171
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172 /*
173 * Choose an address to map it to.
174 * Once the vmalloc system is running, we use it.
e974cd4b 175 * Before then, we use space going down from IOREMAP_TOP
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176 * (ioremap_bot records where we're up to).
177 */
178 p = addr & PAGE_MASK;
179 size = PAGE_ALIGN(addr + size) - p;
180
181 /*
182 * If the address lies within the first 16 MB, assume it's in ISA
183 * memory space
184 */
185 if (p < 16*1024*1024)
186 p += _ISA_MEM_BASE;
187
01695a96 188#ifndef CONFIG_CRASH_DUMP
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189 /*
190 * Don't allow anybody to remap normal RAM that we're using.
191 * mem_init() sets high_memory so only do the check after that.
192 */
f691fa10 193 if (slab_is_available() && (p < virt_to_phys(high_memory)) &&
95f72d1e 194 !(__allow_ioremap_reserved && memblock_is_region_reserved(p, size))) {
cc83458d 195 printk("__ioremap(): phys addr 0x%llx is RAM lr %ps\n",
37f01d64 196 (unsigned long long)p, __builtin_return_address(0));
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197 return NULL;
198 }
01695a96 199#endif
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200
201 if (size == 0)
202 return NULL;
203
204 /*
205 * Is it already mapped? Perhaps overlapped by a previous
3084cdb7 206 * mapping.
14cf11af 207 */
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208 v = p_block_mapped(p);
209 if (v)
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210 goto out;
211
f691fa10 212 if (slab_is_available()) {
14cf11af 213 struct vm_struct *area;
1cdab55d 214 area = get_vm_area_caller(size, VM_IOREMAP, caller);
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215 if (area == 0)
216 return NULL;
7a9d1256 217 area->phys_addr = p;
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218 v = (unsigned long) area->addr;
219 } else {
220 v = (ioremap_bot -= size);
221 }
222
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223 /*
224 * Should check if it is a candidate for a BAT mapping
225 */
226
227 err = 0;
228 for (i = 0; i < size && err == 0; i += PAGE_SIZE)
229 err = map_page(v+i, p+i, flags);
230 if (err) {
f691fa10 231 if (slab_is_available())
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232 vunmap((void *)v);
233 return NULL;
234 }
235
236out:
237 return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK));
238}
920573bd 239EXPORT_SYMBOL(__ioremap);
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240
241void iounmap(volatile void __iomem *addr)
242{
243 /*
244 * If mapped by BATs then there is nothing to do.
245 * Calling vfree() generates a benign warning.
246 */
3084cdb7
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247 if (v_block_mapped((unsigned long)addr))
248 return;
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249
250 if (addr > high_memory && (unsigned long) addr < ioremap_bot)
251 vunmap((void *) (PAGE_MASK & (unsigned long)addr));
252}
920573bd 253EXPORT_SYMBOL(iounmap);
14cf11af 254
68a64357 255int map_page(unsigned long va, phys_addr_t pa, int flags)
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256{
257 pmd_t *pd;
258 pte_t *pg;
259 int err = -ENOMEM;
260
14cf11af 261 /* Use upper 10 bits of VA to index the first level map */
d1953c88 262 pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va);
14cf11af 263 /* Use middle 10 bits of VA to index the second-level map */
e2f2e58e 264 pg = pte_alloc_kernel(pd, va);
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265 if (pg != 0) {
266 err = 0;
3be4e699
BH
267 /* The PTE should never be already set nor present in the
268 * hash table
269 */
7021d86a
AV
270 BUG_ON((pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)) &&
271 flags);
3be4e699
BH
272 set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT,
273 __pgprot(flags)));
14cf11af 274 }
47ce8af4 275 smp_wmb();
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276 return err;
277}
278
279/*
de32400d 280 * Map in a chunk of physical memory starting at start.
14cf11af 281 */
de32400d 282void __init __mapin_ram_chunk(unsigned long offset, unsigned long top)
14cf11af 283{
99c62dd7
KG
284 unsigned long v, s, f;
285 phys_addr_t p;
ee4f2ea4 286 int ktext;
14cf11af 287
de32400d 288 s = offset;
ccdcef72 289 v = PAGE_OFFSET + s;
99c62dd7 290 p = memstart_addr + s;
de32400d 291 for (; s < top; s += PAGE_SIZE) {
060ef9d8
CL
292 ktext = ((char *)v >= _stext && (char *)v < etext) ||
293 ((char *)v >= _sinittext && (char *)v < _einittext);
4f9c53c8 294 f = ktext ? pgprot_val(PAGE_KERNEL_TEXT) : pgprot_val(PAGE_KERNEL);
14cf11af 295 map_page(v, p, f);
ee4f2ea4
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296#ifdef CONFIG_PPC_STD_MMU_32
297 if (ktext)
298 hash_preload(&init_mm, v, 0, 0x300);
299#endif
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300 v += PAGE_SIZE;
301 p += PAGE_SIZE;
302 }
303}
304
de32400d
AH
305void __init mapin_ram(void)
306{
307 unsigned long s, top;
308
309#ifndef CONFIG_WII
310 top = total_lowmem;
311 s = mmu_mapin_ram(top);
312 __mapin_ram_chunk(s, top);
313#else
314 if (!wii_hole_size) {
315 s = mmu_mapin_ram(total_lowmem);
316 __mapin_ram_chunk(s, total_lowmem);
317 } else {
318 top = wii_hole_start;
319 s = mmu_mapin_ram(top);
320 __mapin_ram_chunk(s, top);
321
95f72d1e 322 top = memblock_end_of_DRAM();
de32400d
AH
323 s = wii_mmu_mapin_mem2(top);
324 __mapin_ram_chunk(s, top);
325 }
326#endif
327}
328
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329/* Scan the real Linux page tables and return a PTE pointer for
330 * a virtual address in a context.
331 * Returns true (1) if PTE was found, zero otherwise. The pointer to
332 * the PTE pointer is unmodified if PTE is not found.
333 */
334int
bab70a4a 335get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp)
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336{
337 pgd_t *pgd;
d1953c88 338 pud_t *pud;
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339 pmd_t *pmd;
340 pte_t *pte;
341 int retval = 0;
342
343 pgd = pgd_offset(mm, addr & PAGE_MASK);
344 if (pgd) {
d1953c88
DG
345 pud = pud_offset(pgd, addr & PAGE_MASK);
346 if (pud && pud_present(*pud)) {
347 pmd = pmd_offset(pud, addr & PAGE_MASK);
348 if (pmd_present(*pmd)) {
349 pte = pte_offset_map(pmd, addr & PAGE_MASK);
350 if (pte) {
351 retval = 1;
352 *ptep = pte;
353 if (pmdp)
354 *pmdp = pmd;
355 /* XXX caller needs to do pte_unmap, yuck */
356 }
357 }
358 }
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359 }
360 return(retval);
361}
362
88df6e90
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363#ifdef CONFIG_DEBUG_PAGEALLOC
364
365static int __change_page_attr(struct page *page, pgprot_t prot)
366{
367 pte_t *kpte;
368 pmd_t *kpmd;
369 unsigned long address;
370
371 BUG_ON(PageHighMem(page));
372 address = (unsigned long)page_address(page);
373
3084cdb7 374 if (v_block_mapped(address))
88df6e90
BH
375 return 0;
376 if (!get_pteptr(&init_mm, address, &kpte, &kpmd))
377 return -EINVAL;
50891457 378 __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0);
88df6e90 379 wmb();
f63837f0 380 flush_tlb_page(NULL, address);
88df6e90
BH
381 pte_unmap(kpte);
382
383 return 0;
384}
385
386/*
387 * Change the page attributes of an page in the linear mapping.
388 *
389 * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY
390 */
391static int change_page_attr(struct page *page, int numpages, pgprot_t prot)
392{
393 int i, err = 0;
394 unsigned long flags;
395
396 local_irq_save(flags);
397 for (i = 0; i < numpages; i++, page++) {
398 err = __change_page_attr(page, prot);
399 if (err)
400 break;
401 }
402 local_irq_restore(flags);
403 return err;
404}
405
406
031bc574 407void __kernel_map_pages(struct page *page, int numpages, int enable)
88df6e90
BH
408{
409 if (PageHighMem(page))
410 return;
411
412 change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0));
413}
414#endif /* CONFIG_DEBUG_PAGEALLOC */
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415
416static int fixmaps;
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417
418void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags)
419{
420 unsigned long address = __fix_to_virt(idx);
421
422 if (idx >= __end_of_fixed_addresses) {
423 BUG();
424 return;
425 }
426
46a74179 427 map_page(address, phys, pgprot_val(flags));
2c419bde
KG
428 fixmaps++;
429}
430
431void __this_fixmap_does_not_exist(void)
432{
433 WARN_ON(1);
434}
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