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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 | |
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 | ||
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> | |
29 | #include <linux/lmb.h> | |
30 | #include <linux/slab.h> | |
31 | ||
32 | #include <asm/pgtable.h> | |
33 | #include <asm/pgalloc.h> | |
34 | #include <asm/fixmap.h> | |
35 | #include <asm/io.h> | |
36 | ||
37 | #include "mmu_decl.h" | |
38 | ||
39 | unsigned long ioremap_base; | |
40 | unsigned long ioremap_bot; | |
41 | EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */ | |
42 | ||
43 | #if defined(CONFIG_6xx) || defined(CONFIG_POWER3) | |
44 | #define HAVE_BATS 1 | |
45 | #endif | |
46 | ||
47 | #if defined(CONFIG_FSL_BOOKE) | |
48 | #define HAVE_TLBCAM 1 | |
49 | #endif | |
50 | ||
51 | extern char etext[], _stext[]; | |
52 | ||
53 | #ifdef HAVE_BATS | |
54 | extern phys_addr_t v_mapped_by_bats(unsigned long va); | |
55 | extern unsigned long p_mapped_by_bats(phys_addr_t pa); | |
56 | void setbat(int index, unsigned long virt, phys_addr_t phys, | |
57 | unsigned int size, int flags); | |
58 | ||
59 | #else /* !HAVE_BATS */ | |
60 | #define v_mapped_by_bats(x) (0UL) | |
61 | #define p_mapped_by_bats(x) (0UL) | |
62 | #endif /* HAVE_BATS */ | |
63 | ||
64 | #ifdef HAVE_TLBCAM | |
65 | extern unsigned int tlbcam_index; | |
66 | extern phys_addr_t v_mapped_by_tlbcam(unsigned long va); | |
67 | extern unsigned long p_mapped_by_tlbcam(phys_addr_t pa); | |
68 | #else /* !HAVE_TLBCAM */ | |
69 | #define v_mapped_by_tlbcam(x) (0UL) | |
70 | #define p_mapped_by_tlbcam(x) (0UL) | |
71 | #endif /* HAVE_TLBCAM */ | |
72 | ||
73 | #define PGDIR_ORDER (32 + PGD_T_LOG2 - PGDIR_SHIFT) | |
74 | ||
75 | pgd_t *pgd_alloc(struct mm_struct *mm) | |
76 | { | |
77 | pgd_t *ret; | |
78 | ||
79 | /* pgdir take page or two with 4K pages and a page fraction otherwise */ | |
80 | #ifndef CONFIG_PPC_4K_PAGES | |
81 | ret = (pgd_t *)kzalloc(1 << PGDIR_ORDER, GFP_KERNEL); | |
82 | #else | |
83 | ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, | |
84 | PGDIR_ORDER - PAGE_SHIFT); | |
85 | #endif | |
86 | return ret; | |
87 | } | |
88 | ||
89 | void pgd_free(struct mm_struct *mm, pgd_t *pgd) | |
90 | { | |
91 | #ifndef CONFIG_PPC_4K_PAGES | |
92 | kfree((void *)pgd); | |
93 | #else | |
94 | free_pages((unsigned long)pgd, PGDIR_ORDER - PAGE_SHIFT); | |
95 | #endif | |
96 | } | |
97 | ||
98 | __init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) | |
99 | { | |
100 | pte_t *pte; | |
101 | extern int mem_init_done; | |
102 | extern void *early_get_page(void); | |
103 | ||
104 | if (mem_init_done) { | |
105 | pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); | |
106 | } else { | |
107 | pte = (pte_t *)early_get_page(); | |
108 | if (pte) | |
109 | clear_page(pte); | |
110 | } | |
111 | return pte; | |
112 | } | |
113 | ||
114 | pgtable_t pte_alloc_one(struct mm_struct *mm, unsigned long address) | |
115 | { | |
116 | struct page *ptepage; | |
117 | ||
118 | #ifdef CONFIG_HIGHPTE | |
119 | gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT | __GFP_ZERO; | |
120 | #else | |
121 | gfp_t flags = GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO; | |
122 | #endif | |
123 | ||
124 | ptepage = alloc_pages(flags, 0); | |
125 | if (!ptepage) | |
126 | return NULL; | |
127 | pgtable_page_ctor(ptepage); | |
128 | return ptepage; | |
129 | } | |
130 | ||
131 | void __iomem * | |
132 | ioremap(phys_addr_t addr, unsigned long size) | |
133 | { | |
134 | return __ioremap_caller(addr, size, _PAGE_NO_CACHE | _PAGE_GUARDED, | |
135 | __builtin_return_address(0)); | |
136 | } | |
137 | EXPORT_SYMBOL(ioremap); | |
138 | ||
139 | void __iomem * | |
140 | ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags) | |
141 | { | |
142 | /* writeable implies dirty for kernel addresses */ | |
143 | if (flags & _PAGE_RW) | |
144 | flags |= _PAGE_DIRTY | _PAGE_HWWRITE; | |
145 | ||
146 | /* we don't want to let _PAGE_USER and _PAGE_EXEC leak out */ | |
147 | flags &= ~(_PAGE_USER | _PAGE_EXEC); | |
148 | ||
149 | return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); | |
150 | } | |
151 | EXPORT_SYMBOL(ioremap_flags); | |
152 | ||
153 | void __iomem * | |
154 | __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) | |
155 | { | |
156 | return __ioremap_caller(addr, size, flags, __builtin_return_address(0)); | |
157 | } | |
158 | ||
159 | void __iomem * | |
160 | __ioremap_caller(phys_addr_t addr, unsigned long size, unsigned long flags, | |
161 | void *caller) | |
162 | { | |
163 | unsigned long v, i; | |
164 | phys_addr_t p; | |
165 | int err; | |
166 | ||
167 | /* Make sure we have the base flags */ | |
168 | if ((flags & _PAGE_PRESENT) == 0) | |
169 | flags |= PAGE_KERNEL; | |
170 | ||
171 | /* Non-cacheable page cannot be coherent */ | |
172 | if (flags & _PAGE_NO_CACHE) | |
173 | flags &= ~_PAGE_COHERENT; | |
174 | ||
175 | /* | |
176 | * Choose an address to map it to. | |
177 | * Once the vmalloc system is running, we use it. | |
178 | * Before then, we use space going down from ioremap_base | |
179 | * (ioremap_bot records where we're up to). | |
180 | */ | |
181 | p = addr & PAGE_MASK; | |
182 | size = PAGE_ALIGN(addr + size) - p; | |
183 | ||
184 | /* | |
185 | * If the address lies within the first 16 MB, assume it's in ISA | |
186 | * memory space | |
187 | */ | |
188 | if (p < 16*1024*1024) | |
189 | p += _ISA_MEM_BASE; | |
190 | ||
191 | #ifndef CONFIG_CRASH_DUMP | |
192 | /* | |
193 | * Don't allow anybody to remap normal RAM that we're using. | |
194 | * mem_init() sets high_memory so only do the check after that. | |
195 | */ | |
196 | if (mem_init_done && (p < virt_to_phys(high_memory)) && | |
197 | !(__allow_ioremap_reserved && lmb_is_region_reserved(p, size))) { | |
198 | printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n", | |
199 | (unsigned long long)p, __builtin_return_address(0)); | |
200 | return NULL; | |
201 | } | |
202 | #endif | |
203 | ||
204 | if (size == 0) | |
205 | return NULL; | |
206 | ||
207 | /* | |
208 | * Is it already mapped? Perhaps overlapped by a previous | |
209 | * BAT mapping. If the whole area is mapped then we're done, | |
210 | * otherwise remap it since we want to keep the virt addrs for | |
211 | * each request contiguous. | |
212 | * | |
213 | * We make the assumption here that if the bottom and top | |
214 | * of the range we want are mapped then it's mapped to the | |
215 | * same virt address (and this is contiguous). | |
216 | * -- Cort | |
217 | */ | |
218 | if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ ) | |
219 | goto out; | |
220 | ||
221 | if ((v = p_mapped_by_tlbcam(p))) | |
222 | goto out; | |
223 | ||
224 | if (mem_init_done) { | |
225 | struct vm_struct *area; | |
226 | area = get_vm_area_caller(size, VM_IOREMAP, caller); | |
227 | if (area == 0) | |
228 | return NULL; | |
229 | v = (unsigned long) area->addr; | |
230 | } else { | |
231 | v = (ioremap_bot -= size); | |
232 | } | |
233 | ||
234 | /* | |
235 | * Should check if it is a candidate for a BAT mapping | |
236 | */ | |
237 | ||
238 | err = 0; | |
239 | for (i = 0; i < size && err == 0; i += PAGE_SIZE) | |
240 | err = map_page(v+i, p+i, flags); | |
241 | if (err) { | |
242 | if (mem_init_done) | |
243 | vunmap((void *)v); | |
244 | return NULL; | |
245 | } | |
246 | ||
247 | out: | |
248 | return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); | |
249 | } | |
250 | EXPORT_SYMBOL(__ioremap); | |
251 | ||
252 | void iounmap(volatile void __iomem *addr) | |
253 | { | |
254 | /* | |
255 | * If mapped by BATs then there is nothing to do. | |
256 | * Calling vfree() generates a benign warning. | |
257 | */ | |
258 | if (v_mapped_by_bats((unsigned long)addr)) return; | |
259 | ||
260 | if (addr > high_memory && (unsigned long) addr < ioremap_bot) | |
261 | vunmap((void *) (PAGE_MASK & (unsigned long)addr)); | |
262 | } | |
263 | EXPORT_SYMBOL(iounmap); | |
264 | ||
265 | int map_page(unsigned long va, phys_addr_t pa, int flags) | |
266 | { | |
267 | pmd_t *pd; | |
268 | pte_t *pg; | |
269 | int err = -ENOMEM; | |
270 | ||
271 | /* Use upper 10 bits of VA to index the first level map */ | |
272 | pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va); | |
273 | /* Use middle 10 bits of VA to index the second-level map */ | |
274 | pg = pte_alloc_kernel(pd, va); | |
275 | if (pg != 0) { | |
276 | err = 0; | |
277 | /* The PTE should never be already set nor present in the | |
278 | * hash table | |
279 | */ | |
280 | BUG_ON((pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)) && | |
281 | flags); | |
282 | set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, | |
283 | __pgprot(flags))); | |
284 | } | |
285 | return err; | |
286 | } | |
287 | ||
288 | /* | |
289 | * Map in a chunk of physical memory starting at start. | |
290 | */ | |
291 | void __init __mapin_ram_chunk(unsigned long offset, unsigned long top) | |
292 | { | |
293 | unsigned long v, s, f; | |
294 | phys_addr_t p; | |
295 | int ktext; | |
296 | ||
297 | s = offset; | |
298 | v = PAGE_OFFSET + s; | |
299 | p = memstart_addr + s; | |
300 | for (; s < top; s += PAGE_SIZE) { | |
301 | ktext = ((char *) v >= _stext && (char *) v < etext); | |
302 | f = ktext ? PAGE_KERNEL_TEXT : PAGE_KERNEL; | |
303 | map_page(v, p, f); | |
304 | #ifdef CONFIG_PPC_STD_MMU_32 | |
305 | if (ktext) | |
306 | hash_preload(&init_mm, v, 0, 0x300); | |
307 | #endif | |
308 | v += PAGE_SIZE; | |
309 | p += PAGE_SIZE; | |
310 | } | |
311 | } | |
312 | ||
313 | void __init mapin_ram(void) | |
314 | { | |
315 | unsigned long s, top; | |
316 | ||
317 | #ifndef CONFIG_WII | |
318 | top = total_lowmem; | |
319 | s = mmu_mapin_ram(top); | |
320 | __mapin_ram_chunk(s, top); | |
321 | #else | |
322 | if (!wii_hole_size) { | |
323 | s = mmu_mapin_ram(total_lowmem); | |
324 | __mapin_ram_chunk(s, total_lowmem); | |
325 | } else { | |
326 | top = wii_hole_start; | |
327 | s = mmu_mapin_ram(top); | |
328 | __mapin_ram_chunk(s, top); | |
329 | ||
330 | top = lmb_end_of_DRAM(); | |
331 | s = wii_mmu_mapin_mem2(top); | |
332 | __mapin_ram_chunk(s, top); | |
333 | } | |
334 | #endif | |
335 | } | |
336 | ||
337 | /* Scan the real Linux page tables and return a PTE pointer for | |
338 | * a virtual address in a context. | |
339 | * Returns true (1) if PTE was found, zero otherwise. The pointer to | |
340 | * the PTE pointer is unmodified if PTE is not found. | |
341 | */ | |
342 | int | |
343 | get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) | |
344 | { | |
345 | pgd_t *pgd; | |
346 | pud_t *pud; | |
347 | pmd_t *pmd; | |
348 | pte_t *pte; | |
349 | int retval = 0; | |
350 | ||
351 | pgd = pgd_offset(mm, addr & PAGE_MASK); | |
352 | if (pgd) { | |
353 | pud = pud_offset(pgd, addr & PAGE_MASK); | |
354 | if (pud && pud_present(*pud)) { | |
355 | pmd = pmd_offset(pud, addr & PAGE_MASK); | |
356 | if (pmd_present(*pmd)) { | |
357 | pte = pte_offset_map(pmd, addr & PAGE_MASK); | |
358 | if (pte) { | |
359 | retval = 1; | |
360 | *ptep = pte; | |
361 | if (pmdp) | |
362 | *pmdp = pmd; | |
363 | /* XXX caller needs to do pte_unmap, yuck */ | |
364 | } | |
365 | } | |
366 | } | |
367 | } | |
368 | return(retval); | |
369 | } | |
370 | ||
371 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
372 | ||
373 | static int __change_page_attr(struct page *page, pgprot_t prot) | |
374 | { | |
375 | pte_t *kpte; | |
376 | pmd_t *kpmd; | |
377 | unsigned long address; | |
378 | ||
379 | BUG_ON(PageHighMem(page)); | |
380 | address = (unsigned long)page_address(page); | |
381 | ||
382 | if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address)) | |
383 | return 0; | |
384 | if (!get_pteptr(&init_mm, address, &kpte, &kpmd)) | |
385 | return -EINVAL; | |
386 | __set_pte_at(&init_mm, address, kpte, mk_pte(page, prot), 0); | |
387 | wmb(); | |
388 | #ifdef CONFIG_PPC_STD_MMU | |
389 | flush_hash_pages(0, address, pmd_val(*kpmd), 1); | |
390 | #else | |
391 | flush_tlb_page(NULL, address); | |
392 | #endif | |
393 | pte_unmap(kpte); | |
394 | ||
395 | return 0; | |
396 | } | |
397 | ||
398 | /* | |
399 | * Change the page attributes of an page in the linear mapping. | |
400 | * | |
401 | * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY | |
402 | */ | |
403 | static int change_page_attr(struct page *page, int numpages, pgprot_t prot) | |
404 | { | |
405 | int i, err = 0; | |
406 | unsigned long flags; | |
407 | ||
408 | local_irq_save(flags); | |
409 | for (i = 0; i < numpages; i++, page++) { | |
410 | err = __change_page_attr(page, prot); | |
411 | if (err) | |
412 | break; | |
413 | } | |
414 | local_irq_restore(flags); | |
415 | return err; | |
416 | } | |
417 | ||
418 | ||
419 | void kernel_map_pages(struct page *page, int numpages, int enable) | |
420 | { | |
421 | if (PageHighMem(page)) | |
422 | return; | |
423 | ||
424 | change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); | |
425 | } | |
426 | #endif /* CONFIG_DEBUG_PAGEALLOC */ | |
427 | ||
428 | static int fixmaps; | |
429 | ||
430 | void __set_fixmap (enum fixed_addresses idx, phys_addr_t phys, pgprot_t flags) | |
431 | { | |
432 | unsigned long address = __fix_to_virt(idx); | |
433 | ||
434 | if (idx >= __end_of_fixed_addresses) { | |
435 | BUG(); | |
436 | return; | |
437 | } | |
438 | ||
439 | map_page(address, phys, pgprot_val(flags)); | |
440 | fixmaps++; | |
441 | } | |
442 | ||
443 | void __this_fixmap_does_not_exist(void) | |
444 | { | |
445 | WARN_ON(1); | |
446 | } |