Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/mm/bootmem.c | |
3 | * | |
4 | * Copyright (C) 1999 Ingo Molnar | |
5 | * Discontiguous memory support, Kanoj Sarcar, SGI, Nov 1999 | |
6 | * | |
7 | * simple boot-time physical memory area allocator and | |
8 | * free memory collector. It's used to deal with reserved | |
9 | * system memory and memory holes as well. | |
10 | */ | |
11 | ||
12 | #include <linux/mm.h> | |
13 | #include <linux/kernel_stat.h> | |
14 | #include <linux/swap.h> | |
15 | #include <linux/interrupt.h> | |
16 | #include <linux/init.h> | |
17 | #include <linux/bootmem.h> | |
18 | #include <linux/mmzone.h> | |
19 | #include <linux/module.h> | |
20 | #include <asm/dma.h> | |
21 | #include <asm/io.h> | |
22 | #include "internal.h" | |
23 | ||
24 | /* | |
25 | * Access to this subsystem has to be serialized externally. (this is | |
26 | * true for the boot process anyway) | |
27 | */ | |
28 | unsigned long max_low_pfn; | |
29 | unsigned long min_low_pfn; | |
30 | unsigned long max_pfn; | |
31 | ||
32 | EXPORT_SYMBOL(max_pfn); /* This is exported so | |
33 | * dma_get_required_mask(), which uses | |
34 | * it, can be an inline function */ | |
35 | ||
36 | /* return the number of _pages_ that will be allocated for the boot bitmap */ | |
37 | unsigned long __init bootmem_bootmap_pages (unsigned long pages) | |
38 | { | |
39 | unsigned long mapsize; | |
40 | ||
41 | mapsize = (pages+7)/8; | |
42 | mapsize = (mapsize + ~PAGE_MASK) & PAGE_MASK; | |
43 | mapsize >>= PAGE_SHIFT; | |
44 | ||
45 | return mapsize; | |
46 | } | |
47 | ||
48 | /* | |
49 | * Called once to set up the allocator itself. | |
50 | */ | |
51 | static unsigned long __init init_bootmem_core (pg_data_t *pgdat, | |
52 | unsigned long mapstart, unsigned long start, unsigned long end) | |
53 | { | |
54 | bootmem_data_t *bdata = pgdat->bdata; | |
55 | unsigned long mapsize = ((end - start)+7)/8; | |
56 | ||
57 | pgdat->pgdat_next = pgdat_list; | |
58 | pgdat_list = pgdat; | |
59 | ||
60 | mapsize = (mapsize + (sizeof(long) - 1UL)) & ~(sizeof(long) - 1UL); | |
61 | bdata->node_bootmem_map = phys_to_virt(mapstart << PAGE_SHIFT); | |
62 | bdata->node_boot_start = (start << PAGE_SHIFT); | |
63 | bdata->node_low_pfn = end; | |
64 | ||
65 | /* | |
66 | * Initially all pages are reserved - setup_arch() has to | |
67 | * register free RAM areas explicitly. | |
68 | */ | |
69 | memset(bdata->node_bootmem_map, 0xff, mapsize); | |
70 | ||
71 | return mapsize; | |
72 | } | |
73 | ||
74 | /* | |
75 | * Marks a particular physical memory range as unallocatable. Usable RAM | |
76 | * might be used for boot-time allocations - or it might get added | |
77 | * to the free page pool later on. | |
78 | */ | |
79 | static void __init reserve_bootmem_core(bootmem_data_t *bdata, unsigned long addr, unsigned long size) | |
80 | { | |
81 | unsigned long i; | |
82 | /* | |
83 | * round up, partially reserved pages are considered | |
84 | * fully reserved. | |
85 | */ | |
86 | unsigned long sidx = (addr - bdata->node_boot_start)/PAGE_SIZE; | |
87 | unsigned long eidx = (addr + size - bdata->node_boot_start + | |
88 | PAGE_SIZE-1)/PAGE_SIZE; | |
89 | unsigned long end = (addr + size + PAGE_SIZE-1)/PAGE_SIZE; | |
90 | ||
91 | BUG_ON(!size); | |
92 | BUG_ON(sidx >= eidx); | |
93 | BUG_ON((addr >> PAGE_SHIFT) >= bdata->node_low_pfn); | |
94 | BUG_ON(end > bdata->node_low_pfn); | |
95 | ||
96 | for (i = sidx; i < eidx; i++) | |
97 | if (test_and_set_bit(i, bdata->node_bootmem_map)) { | |
98 | #ifdef CONFIG_DEBUG_BOOTMEM | |
99 | printk("hm, page %08lx reserved twice.\n", i*PAGE_SIZE); | |
100 | #endif | |
101 | } | |
102 | } | |
103 | ||
104 | static void __init free_bootmem_core(bootmem_data_t *bdata, unsigned long addr, unsigned long size) | |
105 | { | |
106 | unsigned long i; | |
107 | unsigned long start; | |
108 | /* | |
109 | * round down end of usable mem, partially free pages are | |
110 | * considered reserved. | |
111 | */ | |
112 | unsigned long sidx; | |
113 | unsigned long eidx = (addr + size - bdata->node_boot_start)/PAGE_SIZE; | |
114 | unsigned long end = (addr + size)/PAGE_SIZE; | |
115 | ||
116 | BUG_ON(!size); | |
117 | BUG_ON(end > bdata->node_low_pfn); | |
118 | ||
119 | if (addr < bdata->last_success) | |
120 | bdata->last_success = addr; | |
121 | ||
122 | /* | |
123 | * Round up the beginning of the address. | |
124 | */ | |
125 | start = (addr + PAGE_SIZE-1) / PAGE_SIZE; | |
126 | sidx = start - (bdata->node_boot_start/PAGE_SIZE); | |
127 | ||
128 | for (i = sidx; i < eidx; i++) { | |
129 | if (unlikely(!test_and_clear_bit(i, bdata->node_bootmem_map))) | |
130 | BUG(); | |
131 | } | |
132 | } | |
133 | ||
134 | /* | |
135 | * We 'merge' subsequent allocations to save space. We might 'lose' | |
136 | * some fraction of a page if allocations cannot be satisfied due to | |
137 | * size constraints on boxes where there is physical RAM space | |
138 | * fragmentation - in these cases (mostly large memory boxes) this | |
139 | * is not a problem. | |
140 | * | |
141 | * On low memory boxes we get it right in 100% of the cases. | |
142 | * | |
143 | * alignment has to be a power of 2 value. | |
144 | * | |
145 | * NOTE: This function is _not_ reentrant. | |
146 | */ | |
147 | static void * __init | |
148 | __alloc_bootmem_core(struct bootmem_data *bdata, unsigned long size, | |
149 | unsigned long align, unsigned long goal) | |
150 | { | |
151 | unsigned long offset, remaining_size, areasize, preferred; | |
152 | unsigned long i, start = 0, incr, eidx; | |
153 | void *ret; | |
154 | ||
155 | if(!size) { | |
156 | printk("__alloc_bootmem_core(): zero-sized request\n"); | |
157 | BUG(); | |
158 | } | |
159 | BUG_ON(align & (align-1)); | |
160 | ||
161 | eidx = bdata->node_low_pfn - (bdata->node_boot_start >> PAGE_SHIFT); | |
162 | offset = 0; | |
163 | if (align && | |
164 | (bdata->node_boot_start & (align - 1UL)) != 0) | |
165 | offset = (align - (bdata->node_boot_start & (align - 1UL))); | |
166 | offset >>= PAGE_SHIFT; | |
167 | ||
168 | /* | |
169 | * We try to allocate bootmem pages above 'goal' | |
170 | * first, then we try to allocate lower pages. | |
171 | */ | |
172 | if (goal && (goal >= bdata->node_boot_start) && | |
173 | ((goal >> PAGE_SHIFT) < bdata->node_low_pfn)) { | |
174 | preferred = goal - bdata->node_boot_start; | |
175 | ||
176 | if (bdata->last_success >= preferred) | |
177 | preferred = bdata->last_success; | |
178 | } else | |
179 | preferred = 0; | |
180 | ||
181 | preferred = ((preferred + align - 1) & ~(align - 1)) >> PAGE_SHIFT; | |
182 | preferred += offset; | |
183 | areasize = (size+PAGE_SIZE-1)/PAGE_SIZE; | |
184 | incr = align >> PAGE_SHIFT ? : 1; | |
185 | ||
186 | restart_scan: | |
187 | for (i = preferred; i < eidx; i += incr) { | |
188 | unsigned long j; | |
189 | i = find_next_zero_bit(bdata->node_bootmem_map, eidx, i); | |
190 | i = ALIGN(i, incr); | |
191 | if (test_bit(i, bdata->node_bootmem_map)) | |
192 | continue; | |
193 | for (j = i + 1; j < i + areasize; ++j) { | |
194 | if (j >= eidx) | |
195 | goto fail_block; | |
196 | if (test_bit (j, bdata->node_bootmem_map)) | |
197 | goto fail_block; | |
198 | } | |
199 | start = i; | |
200 | goto found; | |
201 | fail_block: | |
202 | i = ALIGN(j, incr); | |
203 | } | |
204 | ||
205 | if (preferred > offset) { | |
206 | preferred = offset; | |
207 | goto restart_scan; | |
208 | } | |
209 | return NULL; | |
210 | ||
211 | found: | |
212 | bdata->last_success = start << PAGE_SHIFT; | |
213 | BUG_ON(start >= eidx); | |
214 | ||
215 | /* | |
216 | * Is the next page of the previous allocation-end the start | |
217 | * of this allocation's buffer? If yes then we can 'merge' | |
218 | * the previous partial page with this allocation. | |
219 | */ | |
220 | if (align < PAGE_SIZE && | |
221 | bdata->last_offset && bdata->last_pos+1 == start) { | |
222 | offset = (bdata->last_offset+align-1) & ~(align-1); | |
223 | BUG_ON(offset > PAGE_SIZE); | |
224 | remaining_size = PAGE_SIZE-offset; | |
225 | if (size < remaining_size) { | |
226 | areasize = 0; | |
227 | /* last_pos unchanged */ | |
228 | bdata->last_offset = offset+size; | |
229 | ret = phys_to_virt(bdata->last_pos*PAGE_SIZE + offset + | |
230 | bdata->node_boot_start); | |
231 | } else { | |
232 | remaining_size = size - remaining_size; | |
233 | areasize = (remaining_size+PAGE_SIZE-1)/PAGE_SIZE; | |
234 | ret = phys_to_virt(bdata->last_pos*PAGE_SIZE + offset + | |
235 | bdata->node_boot_start); | |
236 | bdata->last_pos = start+areasize-1; | |
237 | bdata->last_offset = remaining_size; | |
238 | } | |
239 | bdata->last_offset &= ~PAGE_MASK; | |
240 | } else { | |
241 | bdata->last_pos = start + areasize - 1; | |
242 | bdata->last_offset = size & ~PAGE_MASK; | |
243 | ret = phys_to_virt(start * PAGE_SIZE + bdata->node_boot_start); | |
244 | } | |
245 | ||
246 | /* | |
247 | * Reserve the area now: | |
248 | */ | |
249 | for (i = start; i < start+areasize; i++) | |
250 | if (unlikely(test_and_set_bit(i, bdata->node_bootmem_map))) | |
251 | BUG(); | |
252 | memset(ret, 0, size); | |
253 | return ret; | |
254 | } | |
255 | ||
256 | static unsigned long __init free_all_bootmem_core(pg_data_t *pgdat) | |
257 | { | |
258 | struct page *page; | |
259 | bootmem_data_t *bdata = pgdat->bdata; | |
260 | unsigned long i, count, total = 0; | |
261 | unsigned long idx; | |
262 | unsigned long *map; | |
263 | int gofast = 0; | |
264 | ||
265 | BUG_ON(!bdata->node_bootmem_map); | |
266 | ||
267 | count = 0; | |
268 | /* first extant page of the node */ | |
269 | page = virt_to_page(phys_to_virt(bdata->node_boot_start)); | |
270 | idx = bdata->node_low_pfn - (bdata->node_boot_start >> PAGE_SHIFT); | |
271 | map = bdata->node_bootmem_map; | |
272 | /* Check physaddr is O(LOG2(BITS_PER_LONG)) page aligned */ | |
273 | if (bdata->node_boot_start == 0 || | |
274 | ffs(bdata->node_boot_start) - PAGE_SHIFT > ffs(BITS_PER_LONG)) | |
275 | gofast = 1; | |
276 | for (i = 0; i < idx; ) { | |
277 | unsigned long v = ~map[i / BITS_PER_LONG]; | |
278 | if (gofast && v == ~0UL) { | |
279 | int j, order; | |
280 | ||
281 | count += BITS_PER_LONG; | |
282 | __ClearPageReserved(page); | |
283 | order = ffs(BITS_PER_LONG) - 1; | |
284 | set_page_refs(page, order); | |
285 | for (j = 1; j < BITS_PER_LONG; j++) { | |
286 | if (j + 16 < BITS_PER_LONG) | |
287 | prefetchw(page + j + 16); | |
288 | __ClearPageReserved(page + j); | |
289 | } | |
290 | __free_pages(page, order); | |
291 | i += BITS_PER_LONG; | |
292 | page += BITS_PER_LONG; | |
293 | } else if (v) { | |
294 | unsigned long m; | |
295 | for (m = 1; m && i < idx; m<<=1, page++, i++) { | |
296 | if (v & m) { | |
297 | count++; | |
298 | __ClearPageReserved(page); | |
299 | set_page_refs(page, 0); | |
300 | __free_page(page); | |
301 | } | |
302 | } | |
303 | } else { | |
304 | i+=BITS_PER_LONG; | |
305 | page += BITS_PER_LONG; | |
306 | } | |
307 | } | |
308 | total += count; | |
309 | ||
310 | /* | |
311 | * Now free the allocator bitmap itself, it's not | |
312 | * needed anymore: | |
313 | */ | |
314 | page = virt_to_page(bdata->node_bootmem_map); | |
315 | count = 0; | |
316 | for (i = 0; i < ((bdata->node_low_pfn-(bdata->node_boot_start >> PAGE_SHIFT))/8 + PAGE_SIZE-1)/PAGE_SIZE; i++,page++) { | |
317 | count++; | |
318 | __ClearPageReserved(page); | |
319 | set_page_count(page, 1); | |
320 | __free_page(page); | |
321 | } | |
322 | total += count; | |
323 | bdata->node_bootmem_map = NULL; | |
324 | ||
325 | return total; | |
326 | } | |
327 | ||
328 | unsigned long __init init_bootmem_node (pg_data_t *pgdat, unsigned long freepfn, unsigned long startpfn, unsigned long endpfn) | |
329 | { | |
330 | return(init_bootmem_core(pgdat, freepfn, startpfn, endpfn)); | |
331 | } | |
332 | ||
333 | void __init reserve_bootmem_node (pg_data_t *pgdat, unsigned long physaddr, unsigned long size) | |
334 | { | |
335 | reserve_bootmem_core(pgdat->bdata, physaddr, size); | |
336 | } | |
337 | ||
338 | void __init free_bootmem_node (pg_data_t *pgdat, unsigned long physaddr, unsigned long size) | |
339 | { | |
340 | free_bootmem_core(pgdat->bdata, physaddr, size); | |
341 | } | |
342 | ||
343 | unsigned long __init free_all_bootmem_node (pg_data_t *pgdat) | |
344 | { | |
345 | return(free_all_bootmem_core(pgdat)); | |
346 | } | |
347 | ||
348 | unsigned long __init init_bootmem (unsigned long start, unsigned long pages) | |
349 | { | |
350 | max_low_pfn = pages; | |
351 | min_low_pfn = start; | |
352 | return(init_bootmem_core(NODE_DATA(0), start, 0, pages)); | |
353 | } | |
354 | ||
355 | #ifndef CONFIG_HAVE_ARCH_BOOTMEM_NODE | |
356 | void __init reserve_bootmem (unsigned long addr, unsigned long size) | |
357 | { | |
358 | reserve_bootmem_core(NODE_DATA(0)->bdata, addr, size); | |
359 | } | |
360 | #endif /* !CONFIG_HAVE_ARCH_BOOTMEM_NODE */ | |
361 | ||
362 | void __init free_bootmem (unsigned long addr, unsigned long size) | |
363 | { | |
364 | free_bootmem_core(NODE_DATA(0)->bdata, addr, size); | |
365 | } | |
366 | ||
367 | unsigned long __init free_all_bootmem (void) | |
368 | { | |
369 | return(free_all_bootmem_core(NODE_DATA(0))); | |
370 | } | |
371 | ||
372 | void * __init __alloc_bootmem (unsigned long size, unsigned long align, unsigned long goal) | |
373 | { | |
374 | pg_data_t *pgdat = pgdat_list; | |
375 | void *ptr; | |
376 | ||
377 | for_each_pgdat(pgdat) | |
378 | if ((ptr = __alloc_bootmem_core(pgdat->bdata, size, | |
379 | align, goal))) | |
380 | return(ptr); | |
381 | ||
382 | /* | |
383 | * Whoops, we cannot satisfy the allocation request. | |
384 | */ | |
385 | printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size); | |
386 | panic("Out of memory"); | |
387 | return NULL; | |
388 | } | |
389 | ||
390 | void * __init __alloc_bootmem_node (pg_data_t *pgdat, unsigned long size, unsigned long align, unsigned long goal) | |
391 | { | |
392 | void *ptr; | |
393 | ||
394 | ptr = __alloc_bootmem_core(pgdat->bdata, size, align, goal); | |
395 | if (ptr) | |
396 | return (ptr); | |
397 | ||
398 | return __alloc_bootmem(size, align, goal); | |
399 | } | |
400 |