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14cf11af PM |
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 | * Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk). | |
12 | * | |
13 | * Derived from "arch/i386/mm/init.c" | |
14 | * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds | |
15 | * | |
16 | * This program is free software; you can redistribute it and/or | |
17 | * modify it under the terms of the GNU General Public License | |
18 | * as published by the Free Software Foundation; either version | |
19 | * 2 of the License, or (at your option) any later version. | |
20 | * | |
21 | */ | |
22 | ||
14cf11af PM |
23 | #include <linux/kernel.h> |
24 | #include <linux/module.h> | |
25 | #include <linux/types.h> | |
26 | #include <linux/mm.h> | |
27 | #include <linux/vmalloc.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/highmem.h> | |
30 | ||
31 | #include <asm/pgtable.h> | |
32 | #include <asm/pgalloc.h> | |
33 | #include <asm/io.h> | |
34 | ||
35 | #include "mmu_decl.h" | |
36 | ||
37 | unsigned long ioremap_base; | |
38 | unsigned long ioremap_bot; | |
920573bd | 39 | EXPORT_SYMBOL(ioremap_bot); /* aka VMALLOC_END */ |
14cf11af PM |
40 | int io_bat_index; |
41 | ||
42 | #if defined(CONFIG_6xx) || defined(CONFIG_POWER3) | |
43 | #define HAVE_BATS 1 | |
44 | #endif | |
45 | ||
46 | #if defined(CONFIG_FSL_BOOKE) | |
47 | #define HAVE_TLBCAM 1 | |
48 | #endif | |
49 | ||
50 | extern char etext[], _stext[]; | |
51 | ||
52 | #ifdef CONFIG_SMP | |
53 | extern void hash_page_sync(void); | |
54 | #endif | |
55 | ||
56 | #ifdef HAVE_BATS | |
57 | extern unsigned long v_mapped_by_bats(unsigned long va); | |
58 | extern unsigned long p_mapped_by_bats(unsigned long pa); | |
59 | void setbat(int index, unsigned long virt, unsigned long phys, | |
60 | unsigned int size, int flags); | |
61 | ||
62 | #else /* !HAVE_BATS */ | |
63 | #define v_mapped_by_bats(x) (0UL) | |
64 | #define p_mapped_by_bats(x) (0UL) | |
65 | #endif /* HAVE_BATS */ | |
66 | ||
67 | #ifdef HAVE_TLBCAM | |
68 | extern unsigned int tlbcam_index; | |
69 | extern unsigned long v_mapped_by_tlbcam(unsigned long va); | |
70 | extern unsigned long p_mapped_by_tlbcam(unsigned long pa); | |
71 | #else /* !HAVE_TLBCAM */ | |
72 | #define v_mapped_by_tlbcam(x) (0UL) | |
73 | #define p_mapped_by_tlbcam(x) (0UL) | |
74 | #endif /* HAVE_TLBCAM */ | |
75 | ||
76 | #ifdef CONFIG_PTE_64BIT | |
77 | /* 44x uses an 8kB pgdir because it has 8-byte Linux PTEs. */ | |
78 | #define PGDIR_ORDER 1 | |
79 | #else | |
80 | #define PGDIR_ORDER 0 | |
81 | #endif | |
82 | ||
83 | pgd_t *pgd_alloc(struct mm_struct *mm) | |
84 | { | |
85 | pgd_t *ret; | |
86 | ||
87 | ret = (pgd_t *)__get_free_pages(GFP_KERNEL|__GFP_ZERO, PGDIR_ORDER); | |
88 | return ret; | |
89 | } | |
90 | ||
91 | void pgd_free(pgd_t *pgd) | |
92 | { | |
93 | free_pages((unsigned long)pgd, PGDIR_ORDER); | |
94 | } | |
95 | ||
96 | pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address) | |
97 | { | |
98 | pte_t *pte; | |
99 | extern int mem_init_done; | |
100 | extern void *early_get_page(void); | |
101 | ||
102 | if (mem_init_done) { | |
103 | pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO); | |
104 | } else { | |
105 | pte = (pte_t *)early_get_page(); | |
106 | if (pte) | |
107 | clear_page(pte); | |
108 | } | |
109 | return pte; | |
110 | } | |
111 | ||
112 | struct page *pte_alloc_one(struct mm_struct *mm, unsigned long address) | |
113 | { | |
114 | struct page *ptepage; | |
115 | ||
116 | #ifdef CONFIG_HIGHPTE | |
3ee1fcac | 117 | gfp_t flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT; |
14cf11af | 118 | #else |
3ee1fcac | 119 | gfp_t flags = GFP_KERNEL | __GFP_REPEAT; |
14cf11af PM |
120 | #endif |
121 | ||
122 | ptepage = alloc_pages(flags, 0); | |
123 | if (ptepage) | |
124 | clear_highpage(ptepage); | |
125 | return ptepage; | |
126 | } | |
127 | ||
128 | void pte_free_kernel(pte_t *pte) | |
129 | { | |
130 | #ifdef CONFIG_SMP | |
131 | hash_page_sync(); | |
132 | #endif | |
133 | free_page((unsigned long)pte); | |
134 | } | |
135 | ||
136 | void pte_free(struct page *ptepage) | |
137 | { | |
138 | #ifdef CONFIG_SMP | |
139 | hash_page_sync(); | |
140 | #endif | |
141 | __free_page(ptepage); | |
142 | } | |
143 | ||
14cf11af PM |
144 | void __iomem * |
145 | ioremap(phys_addr_t addr, unsigned long size) | |
146 | { | |
147 | return __ioremap(addr, size, _PAGE_NO_CACHE); | |
148 | } | |
920573bd | 149 | EXPORT_SYMBOL(ioremap); |
14cf11af | 150 | |
68a64357 BH |
151 | void __iomem * |
152 | ioremap_flags(phys_addr_t addr, unsigned long size, unsigned long flags) | |
153 | { | |
154 | return __ioremap(addr, size, flags); | |
155 | } | |
156 | EXPORT_SYMBOL(ioremap_flags); | |
157 | ||
14cf11af PM |
158 | void __iomem * |
159 | __ioremap(phys_addr_t addr, unsigned long size, unsigned long flags) | |
160 | { | |
161 | unsigned long v, i; | |
162 | phys_addr_t p; | |
163 | int err; | |
164 | ||
165 | /* | |
166 | * Choose an address to map it to. | |
167 | * Once the vmalloc system is running, we use it. | |
168 | * Before then, we use space going down from ioremap_base | |
169 | * (ioremap_bot records where we're up to). | |
170 | */ | |
171 | p = addr & PAGE_MASK; | |
172 | size = PAGE_ALIGN(addr + size) - p; | |
173 | ||
174 | /* | |
175 | * If the address lies within the first 16 MB, assume it's in ISA | |
176 | * memory space | |
177 | */ | |
178 | if (p < 16*1024*1024) | |
179 | p += _ISA_MEM_BASE; | |
180 | ||
181 | /* | |
182 | * Don't allow anybody to remap normal RAM that we're using. | |
183 | * mem_init() sets high_memory so only do the check after that. | |
184 | */ | |
7c8c6b97 | 185 | if (mem_init_done && (p < virt_to_phys(high_memory))) { |
14cf11af PM |
186 | printk("__ioremap(): phys addr "PHYS_FMT" is RAM lr %p\n", p, |
187 | __builtin_return_address(0)); | |
188 | return NULL; | |
189 | } | |
190 | ||
191 | if (size == 0) | |
192 | return NULL; | |
193 | ||
194 | /* | |
195 | * Is it already mapped? Perhaps overlapped by a previous | |
196 | * BAT mapping. If the whole area is mapped then we're done, | |
197 | * otherwise remap it since we want to keep the virt addrs for | |
198 | * each request contiguous. | |
199 | * | |
200 | * We make the assumption here that if the bottom and top | |
201 | * of the range we want are mapped then it's mapped to the | |
202 | * same virt address (and this is contiguous). | |
203 | * -- Cort | |
204 | */ | |
205 | if ((v = p_mapped_by_bats(p)) /*&& p_mapped_by_bats(p+size-1)*/ ) | |
206 | goto out; | |
207 | ||
208 | if ((v = p_mapped_by_tlbcam(p))) | |
209 | goto out; | |
210 | ||
211 | if (mem_init_done) { | |
212 | struct vm_struct *area; | |
213 | area = get_vm_area(size, VM_IOREMAP); | |
214 | if (area == 0) | |
215 | return NULL; | |
216 | v = (unsigned long) area->addr; | |
217 | } else { | |
218 | v = (ioremap_bot -= size); | |
219 | } | |
220 | ||
221 | if ((flags & _PAGE_PRESENT) == 0) | |
222 | flags |= _PAGE_KERNEL; | |
223 | if (flags & _PAGE_NO_CACHE) | |
224 | flags |= _PAGE_GUARDED; | |
225 | ||
226 | /* | |
227 | * Should check if it is a candidate for a BAT mapping | |
228 | */ | |
229 | ||
230 | err = 0; | |
231 | for (i = 0; i < size && err == 0; i += PAGE_SIZE) | |
232 | err = map_page(v+i, p+i, flags); | |
233 | if (err) { | |
234 | if (mem_init_done) | |
235 | vunmap((void *)v); | |
236 | return NULL; | |
237 | } | |
238 | ||
239 | out: | |
240 | return (void __iomem *) (v + ((unsigned long)addr & ~PAGE_MASK)); | |
241 | } | |
920573bd | 242 | EXPORT_SYMBOL(__ioremap); |
14cf11af PM |
243 | |
244 | void iounmap(volatile void __iomem *addr) | |
245 | { | |
246 | /* | |
247 | * If mapped by BATs then there is nothing to do. | |
248 | * Calling vfree() generates a benign warning. | |
249 | */ | |
250 | if (v_mapped_by_bats((unsigned long)addr)) return; | |
251 | ||
252 | if (addr > high_memory && (unsigned long) addr < ioremap_bot) | |
253 | vunmap((void *) (PAGE_MASK & (unsigned long)addr)); | |
254 | } | |
920573bd | 255 | EXPORT_SYMBOL(iounmap); |
14cf11af | 256 | |
68a64357 | 257 | int map_page(unsigned long va, phys_addr_t pa, int flags) |
14cf11af PM |
258 | { |
259 | pmd_t *pd; | |
260 | pte_t *pg; | |
261 | int err = -ENOMEM; | |
262 | ||
14cf11af PM |
263 | /* Use upper 10 bits of VA to index the first level map */ |
264 | pd = pmd_offset(pgd_offset_k(va), va); | |
265 | /* Use middle 10 bits of VA to index the second-level map */ | |
e2f2e58e | 266 | pg = pte_alloc_kernel(pd, va); |
14cf11af PM |
267 | if (pg != 0) { |
268 | err = 0; | |
269 | set_pte_at(&init_mm, va, pg, pfn_pte(pa >> PAGE_SHIFT, __pgprot(flags))); | |
270 | if (mem_init_done) | |
271 | flush_HPTE(0, va, pmd_val(*pd)); | |
272 | } | |
14cf11af PM |
273 | return err; |
274 | } | |
275 | ||
276 | /* | |
277 | * Map in all of physical memory starting at KERNELBASE. | |
278 | */ | |
279 | void __init mapin_ram(void) | |
280 | { | |
281 | unsigned long v, p, s, f; | |
282 | ||
283 | s = mmu_mapin_ram(); | |
284 | v = KERNELBASE + s; | |
285 | p = PPC_MEMSTART + s; | |
286 | for (; s < total_lowmem; s += PAGE_SIZE) { | |
287 | if ((char *) v >= _stext && (char *) v < etext) | |
288 | f = _PAGE_RAM_TEXT; | |
289 | else | |
290 | f = _PAGE_RAM; | |
291 | map_page(v, p, f); | |
292 | v += PAGE_SIZE; | |
293 | p += PAGE_SIZE; | |
294 | } | |
295 | } | |
296 | ||
14cf11af | 297 | /* is x a power of 4? */ |
63c2f782 | 298 | #define is_power_of_4(x) is_power_of_2(x) && (ffs(x) & 1)) |
14cf11af PM |
299 | |
300 | /* | |
301 | * Set up a mapping for a block of I/O. | |
302 | * virt, phys, size must all be page-aligned. | |
303 | * This should only be called before ioremap is called. | |
304 | */ | |
305 | void __init io_block_mapping(unsigned long virt, phys_addr_t phys, | |
306 | unsigned int size, int flags) | |
307 | { | |
308 | int i; | |
309 | ||
310 | if (virt > KERNELBASE && virt < ioremap_bot) | |
311 | ioremap_bot = ioremap_base = virt; | |
312 | ||
313 | #ifdef HAVE_BATS | |
314 | /* | |
315 | * Use a BAT for this if possible... | |
316 | */ | |
317 | if (io_bat_index < 2 && is_power_of_2(size) | |
318 | && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { | |
319 | setbat(io_bat_index, virt, phys, size, flags); | |
320 | ++io_bat_index; | |
321 | return; | |
322 | } | |
323 | #endif /* HAVE_BATS */ | |
324 | ||
325 | #ifdef HAVE_TLBCAM | |
326 | /* | |
327 | * Use a CAM for this if possible... | |
328 | */ | |
329 | if (tlbcam_index < num_tlbcam_entries && is_power_of_4(size) | |
330 | && (virt & (size - 1)) == 0 && (phys & (size - 1)) == 0) { | |
331 | settlbcam(tlbcam_index, virt, phys, size, flags, 0); | |
332 | ++tlbcam_index; | |
333 | return; | |
334 | } | |
335 | #endif /* HAVE_TLBCAM */ | |
336 | ||
337 | /* No BATs available, put it in the page tables. */ | |
338 | for (i = 0; i < size; i += PAGE_SIZE) | |
339 | map_page(virt + i, phys + i, flags); | |
340 | } | |
341 | ||
342 | /* Scan the real Linux page tables and return a PTE pointer for | |
343 | * a virtual address in a context. | |
344 | * Returns true (1) if PTE was found, zero otherwise. The pointer to | |
345 | * the PTE pointer is unmodified if PTE is not found. | |
346 | */ | |
347 | int | |
bab70a4a | 348 | get_pteptr(struct mm_struct *mm, unsigned long addr, pte_t **ptep, pmd_t **pmdp) |
14cf11af PM |
349 | { |
350 | pgd_t *pgd; | |
351 | pmd_t *pmd; | |
352 | pte_t *pte; | |
353 | int retval = 0; | |
354 | ||
355 | pgd = pgd_offset(mm, addr & PAGE_MASK); | |
356 | if (pgd) { | |
357 | pmd = pmd_offset(pgd, addr & PAGE_MASK); | |
358 | if (pmd_present(*pmd)) { | |
359 | pte = pte_offset_map(pmd, addr & PAGE_MASK); | |
360 | if (pte) { | |
361 | retval = 1; | |
362 | *ptep = pte; | |
bab70a4a ES |
363 | if (pmdp) |
364 | *pmdp = pmd; | |
14cf11af PM |
365 | /* XXX caller needs to do pte_unmap, yuck */ |
366 | } | |
367 | } | |
368 | } | |
369 | return(retval); | |
370 | } | |
371 | ||
372 | /* Find physical address for this virtual address. Normally used by | |
373 | * I/O functions, but anyone can call it. | |
374 | */ | |
375 | unsigned long iopa(unsigned long addr) | |
376 | { | |
377 | unsigned long pa; | |
378 | ||
379 | /* I don't know why this won't work on PMacs or CHRP. It | |
380 | * appears there is some bug, or there is some implicit | |
381 | * mapping done not properly represented by BATs or in page | |
382 | * tables.......I am actively working on resolving this, but | |
383 | * can't hold up other stuff. -- Dan | |
384 | */ | |
385 | pte_t *pte; | |
386 | struct mm_struct *mm; | |
387 | ||
388 | /* Check the BATs */ | |
389 | pa = v_mapped_by_bats(addr); | |
390 | if (pa) | |
391 | return pa; | |
392 | ||
393 | /* Allow mapping of user addresses (within the thread) | |
394 | * for DMA if necessary. | |
395 | */ | |
396 | if (addr < TASK_SIZE) | |
397 | mm = current->mm; | |
398 | else | |
399 | mm = &init_mm; | |
400 | ||
401 | pa = 0; | |
bab70a4a | 402 | if (get_pteptr(mm, addr, &pte, NULL)) { |
14cf11af PM |
403 | pa = (pte_val(*pte) & PAGE_MASK) | (addr & ~PAGE_MASK); |
404 | pte_unmap(pte); | |
405 | } | |
406 | ||
407 | return(pa); | |
408 | } | |
409 | ||
410 | /* This is will find the virtual address for a physical one.... | |
411 | * Swiped from APUS, could be dangerous :-). | |
412 | * This is only a placeholder until I really find a way to make this | |
413 | * work. -- Dan | |
414 | */ | |
415 | unsigned long | |
416 | mm_ptov (unsigned long paddr) | |
417 | { | |
418 | unsigned long ret; | |
419 | #if 0 | |
420 | if (paddr < 16*1024*1024) | |
421 | ret = ZTWO_VADDR(paddr); | |
422 | else { | |
423 | int i; | |
424 | ||
425 | for (i = 0; i < kmap_chunk_count;){ | |
426 | unsigned long phys = kmap_chunks[i++]; | |
427 | unsigned long size = kmap_chunks[i++]; | |
428 | unsigned long virt = kmap_chunks[i++]; | |
429 | if (paddr >= phys | |
430 | && paddr < (phys + size)){ | |
431 | ret = virt + paddr - phys; | |
432 | goto exit; | |
433 | } | |
434 | } | |
435 | ||
436 | ret = (unsigned long) __va(paddr); | |
437 | } | |
438 | exit: | |
439 | #ifdef DEBUGPV | |
440 | printk ("PTOV(%lx)=%lx\n", paddr, ret); | |
441 | #endif | |
442 | #else | |
443 | ret = (unsigned long)paddr + KERNELBASE; | |
444 | #endif | |
445 | return ret; | |
446 | } | |
447 |