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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 | ||
30 | #include <asm/pgtable.h> | |
31 | #include <asm/pgalloc.h> | |
32 | #include <asm/io.h> | |
33 | ||
34 | #include "mmu_decl.h" | |
35 | ||
36 | unsigned long ioremap_base; | |
37 | unsigned long ioremap_bot; | |
38 | EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */ | |
39 | ||
40 | #if defined(CONFIG_6xx) || defined(CONFIG_POWER3) | |
41 | #define HAVE_BATS 1 | |
42 | #endif | |
43 | ||
44 | #if defined(CONFIG_FSL_BOOKE) | |
45 | #define HAVE_TLBCAM 1 | |
46 | #endif | |
47 | ||
48 | extern char etext[], _stext[]; | |
49 | ||
50 | #ifdef CONFIG_SMP | |
51 | extern void hash_page_sync(void); | |
52 | #endif | |
53 | ||
54 | #ifdef HAVE_BATS | |
55 | extern unsigned long v_mapped_by_bats(unsigned long va); | |
56 | extern unsigned long p_mapped_by_bats(unsigned long pa); | |
57 | void setbat(int index, unsigned long virt, unsigned long phys, | |
58 | unsigned int size, int flags); | |
59 | ||
60 | #else /* !HAVE_BATS */ | |
61 | #define v_mapped_by_bats(x) (0UL) | |
62 | #define p_mapped_by_bats(x) (0UL) | |
63 | #endif /* HAVE_BATS */ | |
64 | ||
65 | #ifdef HAVE_TLBCAM | |
66 | extern unsigned int tlbcam_index; | |
67 | extern unsigned long v_mapped_by_tlbcam(unsigned long va); | |
68 | extern unsigned long p_mapped_by_tlbcam(unsigned long pa); | |
69 | #else /* !HAVE_TLBCAM */ | |
70 | #define v_mapped_by_tlbcam(x) (0UL) | |
71 | #define p_mapped_by_tlbcam(x) (0UL) | |
72 | #endif /* HAVE_TLBCAM */ | |
73 | ||
74 | #ifdef CONFIG_PTE_64BIT | |
75 | /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */ | |
76 | #define PGDIR_ORDER 1 | |
77 | #else | |
78 | #define PGDIR_ORDER 0 | |
79 | #endif | |
80 | ||
81 | pgd_t *pgd_alloc(struct mm_struct *mm) | |
82 | { | |
83 | pgd_t *ret; | |
84 | ||
85 | ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER); | |
86 | return ret; | |
87 | } | |
88 | ||
89 | void pgd_free(pgd_t *pgd) | |
90 | { | |
91 | free_pages((unsigned long)pgd, PGDIR_ORDER); | |
92 | } | |
93 | ||
94 | __init_refok pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) | |
95 | { | |
96 | pte_t *pte; | |
97 | extern int mem_init_done; | |
98 | extern void *early_get_page(void); | |
99 | ||
100 | if (mem_init_done) { | |
101 | pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); | |
102 | } else { | |
103 | pte = (pte_t *)early_get_page(); | |
104 | if (pte) | |
105 | clear_page(pte); | |
106 | } | |
107 | return pte; | |
108 | } | |
109 | ||
110 | struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) | |
111 | { | |
112 | struct page *ptepage; | |
113 | ||
114 | #ifdef CONFIG_HIGHPTE | |
115 | gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT; | |
116 | #else | |
117 | gfp_t flags = GFP_KERNEL | __GFP_REPEAT; | |
118 | #endif | |
119 | ||
120 | ptepage = alloc_pages(flags, 0); | |
121 | if (ptepage) | |
122 | clear_highpage(ptepage); | |
123 | return ptepage; | |
124 | } | |
125 | ||
126 | void pte_free_kernel(pte_t *pte) | |
127 | { | |
128 | #ifdef CONFIG_SMP | |
129 | hash_page_sync(); | |
130 | #endif | |
131 | free_page((unsigned long)pte); | |
132 | } | |
133 | ||
134 | void pte_free(struct page *ptepage) | |
135 | { | |
136 | #ifdef CONFIG_SMP | |
137 | hash_page_sync(); | |
138 | #endif | |
139 | __free_page(ptepage); | |
140 | } | |
141 | ||
142 | void __iomem * | |
143 | ioremap(phys_addr_t addr, unsigned long size) | |
144 | { | |
145 | return __ioremap(addr, size, _PAGE_NO_CACHE); | |
146 | } | |
147 | EXPORT_SYMBOL(ioremap); | |
148 | ||
149 | void __iomem * | |
150 | ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags) | |
151 | { | |
152 | return __ioremap(addr, size, flags); | |
153 | } | |
154 | EXPORT_SYMBOL(ioremap_flags); | |
155 | ||
156 | void __iomem * | |
157 | __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) | |
158 | { | |
159 | unsigned long v, i; | |
160 | phys_addr_t p; | |
161 | int err; | |
162 | ||
163 | /* | |
164 | * Choose an address to map it to. | |
165 | * Once the vmalloc system is running, we use it. | |
166 | * Before then, we use space going down from ioremap_base | |
167 | * (ioremap_bot records where we're up to). | |
168 | */ | |
169 | p = addr & PAGE_MASK; | |
170 | size = PAGE_ALIGN(addr + size) - p; | |
171 | ||
172 | /* | |
173 | * If the address lies within the first 16 MB, assume it's in ISA | |
174 | * memory space | |
175 | */ | |
176 | if (p < 16*1024*1024) | |
177 | p += _ISA_MEM_BASE; | |
178 | ||
179 | /* | |
180 | * Don't allow anybody to remap normal RAM that we're using. | |
181 | * mem_init() sets high_memory so only do the check after that. | |
182 | */ | |
183 | if (mem_init_done && (p < virt_to_phys(high_memory))) { | |
184 | printk("__ioremap(): phys addr 0x%llx is RAM lr %p\n", | |
185 | (unsigned long long)p, __builtin_return_address(0)); | |
186 | return NULL; | |
187 | } | |
188 | ||
189 | if (size == 0) | |
190 | return NULL; | |
191 | ||
192 | /* | |
193 | * Is it already mapped? Perhaps overlapped by a previous | |
194 | * BAT mapping. If the whole area is mapped then we're done, | |
195 | * otherwise remap it since we want to keep the virt addrs for | |
196 | * each request contiguous. | |
197 | * | |
198 | * We make the assumption here that if the bottom and top | |
199 | * of the range we want are mapped then it's mapped to the | |
200 | * same virt address (and this is contiguous). | |
201 | * -- Cort | |
202 | */ | |
203 | if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ ) | |
204 | goto out; | |
205 | ||
206 | if ((v = p_mapped_by_tlbcam(p))) | |
207 | goto out; | |
208 | ||
209 | if (mem_init_done) { | |
210 | struct vm_struct *area; | |
211 | area = get_vm_area(size, VM_IOREMAP); | |
212 | if (area == 0) | |
213 | return NULL; | |
214 | v = (unsigned long) area->addr; | |
215 | } else { | |
216 | v = (ioremap_bot -= size); | |
217 | } | |
218 | ||
219 | if ((flags & _PAGE_PRESENT) == 0) | |
220 | flags |= _PAGE_KERNEL; | |
221 | if (flags & _PAGE_NO_CACHE) | |
222 | flags |= _PAGE_GUARDED; | |
223 | ||
224 | /* | |
225 | * Should check if it is a candidate for a BAT mapping | |
226 | */ | |
227 | ||
228 | err = 0; | |
229 | for (i = 0; i < size && err == 0; i += PAGE_SIZE) | |
230 | err = map_page(v+i, p+i, flags); | |
231 | if (err) { | |
232 | if (mem_init_done) | |
233 | vunmap((void *)v); | |
234 | return NULL; | |
235 | } | |
236 | ||
237 | out: | |
238 | return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); | |
239 | } | |
240 | EXPORT_SYMBOL(__ioremap); | |
241 | ||
242 | void iounmap(volatile void __iomem *addr) | |
243 | { | |
244 | /* | |
245 | * If mapped by BATs then there is nothing to do. | |
246 | * Calling vfree() generates a benign warning. | |
247 | */ | |
248 | if (v_mapped_by_bats((unsigned long)addr)) return; | |
249 | ||
250 | if (addr > high_memory && (unsigned long) addr < ioremap_bot) | |
251 | vunmap((void *) (PAGE_MASK & (unsigned long)addr)); | |
252 | } | |
253 | EXPORT_SYMBOL(iounmap); | |
254 | ||
255 | int map_page(unsigned long va, phys_addr_t pa, int flags) | |
256 | { | |
257 | pmd_t *pd; | |
258 | pte_t *pg; | |
259 | int err = -ENOMEM; | |
260 | ||
261 | /* Use upper 10 bits of VA to index the first level map */ | |
262 | pd = pmd_offset(pud_offset(pgd_offset_k(va), va), va); | |
263 | /* Use middle 10 bits of VA to index the second-level map */ | |
264 | pg = pte_alloc_kernel(pd, va); | |
265 | if (pg != 0) { | |
266 | err = 0; | |
267 | /* The PTE should never be already set nor present in the | |
268 | * hash table | |
269 | */ | |
270 | BUG_ON(pte_val(*pg) & (_PAGE_PRESENT | _PAGE_HASHPTE)); | |
271 | set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, | |
272 | __pgprot(flags))); | |
273 | } | |
274 | return err; | |
275 | } | |
276 | ||
277 | /* | |
278 | * Map in all of physical memory starting at KERNELBASE. | |
279 | */ | |
280 | void __init mapin_ram(void) | |
281 | { | |
282 | unsigned long v, p, s, f; | |
283 | int ktext; | |
284 | ||
285 | s = mmu_mapin_ram(); | |
286 | v = KERNELBASE + s; | |
287 | p = PPC_MEMSTART + s; | |
288 | for (; s < total_lowmem; s += PAGE_SIZE) { | |
289 | ktext = ((char *) v >= _stext && (char *) v < etext); | |
290 | f = ktext ?_PAGE_RAM_TEXT : _PAGE_RAM; | |
291 | map_page(v, p, f); | |
292 | #ifdef CONFIG_PPC_STD_MMU_32 | |
293 | if (ktext) | |
294 | hash_preload(&init_mm, v, 0, 0x300); | |
295 | #endif | |
296 | v += PAGE_SIZE; | |
297 | p += PAGE_SIZE; | |
298 | } | |
299 | } | |
300 | ||
301 | /* Scan the real Linux page tables and return a PTE pointer for | |
302 | * a virtual address in a context. | |
303 | * Returns true (1) if PTE was found, zero otherwise. The pointer to | |
304 | * the PTE pointer is unmodified if PTE is not found. | |
305 | */ | |
306 | int | |
307 | get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) | |
308 | { | |
309 | pgd_t *pgd; | |
310 | pud_t *pud; | |
311 | pmd_t *pmd; | |
312 | pte_t *pte; | |
313 | int retval = 0; | |
314 | ||
315 | pgd = pgd_offset(mm, addr & PAGE_MASK); | |
316 | if (pgd) { | |
317 | pud = pud_offset(pgd, addr & PAGE_MASK); | |
318 | if (pud && pud_present(*pud)) { | |
319 | pmd = pmd_offset(pud, addr & PAGE_MASK); | |
320 | if (pmd_present(*pmd)) { | |
321 | pte = pte_offset_map(pmd, addr & PAGE_MASK); | |
322 | if (pte) { | |
323 | retval = 1; | |
324 | *ptep = pte; | |
325 | if (pmdp) | |
326 | *pmdp = pmd; | |
327 | /* XXX caller needs to do pte_unmap, yuck */ | |
328 | } | |
329 | } | |
330 | } | |
331 | } | |
332 | return(retval); | |
333 | } | |
334 | ||
335 | #ifdef CONFIG_DEBUG_PAGEALLOC | |
336 | ||
337 | static int __change_page_attr(struct page *page, pgprot_t prot) | |
338 | { | |
339 | pte_t *kpte; | |
340 | pmd_t *kpmd; | |
341 | unsigned long address; | |
342 | ||
343 | BUG_ON(PageHighMem(page)); | |
344 | address = (unsigned long)page_address(page); | |
345 | ||
346 | if (v_mapped_by_bats(address) || v_mapped_by_tlbcam(address)) | |
347 | return 0; | |
348 | if (!get_pteptr(&init_mm, address, &kpte, &kpmd)) | |
349 | return -EINVAL; | |
350 | set_pte_at(&init_mm, address, kpte, mk_pte(page, prot)); | |
351 | wmb(); | |
352 | flush_HPTE(0, address, pmd_val(*kpmd)); | |
353 | pte_unmap(kpte); | |
354 | ||
355 | return 0; | |
356 | } | |
357 | ||
358 | /* | |
359 | * Change the page attributes of an page in the linear mapping. | |
360 | * | |
361 | * THIS CONFLICTS WITH BAT MAPPINGS, DEBUG USE ONLY | |
362 | */ | |
363 | static int change_page_attr(struct page *page, int numpages, pgprot_t prot) | |
364 | { | |
365 | int i, err = 0; | |
366 | unsigned long flags; | |
367 | ||
368 | local_irq_save(flags); | |
369 | for (i = 0; i < numpages; i++, page++) { | |
370 | err = __change_page_attr(page, prot); | |
371 | if (err) | |
372 | break; | |
373 | } | |
374 | local_irq_restore(flags); | |
375 | return err; | |
376 | } | |
377 | ||
378 | ||
379 | void kernel_map_pages(struct page *page, int numpages, int enable) | |
380 | { | |
381 | if (PageHighMem(page)) | |
382 | return; | |
383 | ||
384 | change_page_attr(page, numpages, enable ? PAGE_KERNEL : __pgprot(0)); | |
385 | } | |
386 | #endif /* CONFIG_DEBUG_PAGEALLOC */ |