Commit | Line | Data |
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eefa864b JK |
1 | #include <linux/mm.h> |
2 | #include <linux/mmzone.h> | |
3 | #include <linux/bootmem.h> | |
4 | #include <linux/page_ext.h> | |
5 | #include <linux/memory.h> | |
6 | #include <linux/vmalloc.h> | |
7 | #include <linux/kmemleak.h> | |
48c96a36 | 8 | #include <linux/page_owner.h> |
33c3fc71 | 9 | #include <linux/page_idle.h> |
eefa864b JK |
10 | |
11 | /* | |
12 | * struct page extension | |
13 | * | |
14 | * This is the feature to manage memory for extended data per page. | |
15 | * | |
16 | * Until now, we must modify struct page itself to store extra data per page. | |
17 | * This requires rebuilding the kernel and it is really time consuming process. | |
18 | * And, sometimes, rebuild is impossible due to third party module dependency. | |
19 | * At last, enlarging struct page could cause un-wanted system behaviour change. | |
20 | * | |
21 | * This feature is intended to overcome above mentioned problems. This feature | |
22 | * allocates memory for extended data per page in certain place rather than | |
23 | * the struct page itself. This memory can be accessed by the accessor | |
24 | * functions provided by this code. During the boot process, it checks whether | |
25 | * allocation of huge chunk of memory is needed or not. If not, it avoids | |
26 | * allocating memory at all. With this advantage, we can include this feature | |
27 | * into the kernel in default and can avoid rebuild and solve related problems. | |
28 | * | |
29 | * To help these things to work well, there are two callbacks for clients. One | |
30 | * is the need callback which is mandatory if user wants to avoid useless | |
31 | * memory allocation at boot-time. The other is optional, init callback, which | |
32 | * is used to do proper initialization after memory is allocated. | |
33 | * | |
34 | * The need callback is used to decide whether extended memory allocation is | |
35 | * needed or not. Sometimes users want to deactivate some features in this | |
36 | * boot and extra memory would be unneccessary. In this case, to avoid | |
37 | * allocating huge chunk of memory, each clients represent their need of | |
38 | * extra memory through the need callback. If one of the need callbacks | |
39 | * returns true, it means that someone needs extra memory so that | |
40 | * page extension core should allocates memory for page extension. If | |
41 | * none of need callbacks return true, memory isn't needed at all in this boot | |
42 | * and page extension core can skip to allocate memory. As result, | |
43 | * none of memory is wasted. | |
44 | * | |
45 | * The init callback is used to do proper initialization after page extension | |
46 | * is completely initialized. In sparse memory system, extra memory is | |
47 | * allocated some time later than memmap is allocated. In other words, lifetime | |
48 | * of memory for page extension isn't same with memmap for struct page. | |
49 | * Therefore, clients can't store extra data until page extension is | |
50 | * initialized, even if pages are allocated and used freely. This could | |
51 | * cause inadequate state of extra data per page, so, to prevent it, client | |
52 | * can utilize this callback to initialize the state of it correctly. | |
53 | */ | |
54 | ||
55 | static struct page_ext_operations *page_ext_ops[] = { | |
e30825f1 JK |
56 | &debug_guardpage_ops, |
57 | #ifdef CONFIG_PAGE_POISONING | |
58 | &page_poisoning_ops, | |
59 | #endif | |
48c96a36 JK |
60 | #ifdef CONFIG_PAGE_OWNER |
61 | &page_owner_ops, | |
62 | #endif | |
33c3fc71 VD |
63 | #if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT) |
64 | &page_idle_ops, | |
65 | #endif | |
eefa864b JK |
66 | }; |
67 | ||
68 | static unsigned long total_usage; | |
69 | ||
70 | static bool __init invoke_need_callbacks(void) | |
71 | { | |
72 | int i; | |
73 | int entries = ARRAY_SIZE(page_ext_ops); | |
74 | ||
75 | for (i = 0; i < entries; i++) { | |
76 | if (page_ext_ops[i]->need && page_ext_ops[i]->need()) | |
77 | return true; | |
78 | } | |
79 | ||
80 | return false; | |
81 | } | |
82 | ||
83 | static void __init invoke_init_callbacks(void) | |
84 | { | |
85 | int i; | |
86 | int entries = ARRAY_SIZE(page_ext_ops); | |
87 | ||
88 | for (i = 0; i < entries; i++) { | |
89 | if (page_ext_ops[i]->init) | |
90 | page_ext_ops[i]->init(); | |
91 | } | |
92 | } | |
93 | ||
94 | #if !defined(CONFIG_SPARSEMEM) | |
95 | ||
96 | ||
97 | void __meminit pgdat_page_ext_init(struct pglist_data *pgdat) | |
98 | { | |
99 | pgdat->node_page_ext = NULL; | |
100 | } | |
101 | ||
102 | struct page_ext *lookup_page_ext(struct page *page) | |
103 | { | |
104 | unsigned long pfn = page_to_pfn(page); | |
105 | unsigned long offset; | |
106 | struct page_ext *base; | |
107 | ||
108 | base = NODE_DATA(page_to_nid(page))->node_page_ext; | |
1414c7f4 | 109 | #if defined(CONFIG_DEBUG_VM) || defined(CONFIG_PAGE_POISONING) |
eefa864b JK |
110 | /* |
111 | * The sanity checks the page allocator does upon freeing a | |
112 | * page can reach here before the page_ext arrays are | |
113 | * allocated when feeding a range of pages to the allocator | |
114 | * for the first time during bootup or memory hotplug. | |
1414c7f4 LA |
115 | * |
116 | * This check is also necessary for ensuring page poisoning | |
117 | * works as expected when enabled | |
eefa864b JK |
118 | */ |
119 | if (unlikely(!base)) | |
120 | return NULL; | |
121 | #endif | |
122 | offset = pfn - round_down(node_start_pfn(page_to_nid(page)), | |
123 | MAX_ORDER_NR_PAGES); | |
124 | return base + offset; | |
125 | } | |
126 | ||
127 | static int __init alloc_node_page_ext(int nid) | |
128 | { | |
129 | struct page_ext *base; | |
130 | unsigned long table_size; | |
131 | unsigned long nr_pages; | |
132 | ||
133 | nr_pages = NODE_DATA(nid)->node_spanned_pages; | |
134 | if (!nr_pages) | |
135 | return 0; | |
136 | ||
137 | /* | |
138 | * Need extra space if node range is not aligned with | |
139 | * MAX_ORDER_NR_PAGES. When page allocator's buddy algorithm | |
140 | * checks buddy's status, range could be out of exact node range. | |
141 | */ | |
142 | if (!IS_ALIGNED(node_start_pfn(nid), MAX_ORDER_NR_PAGES) || | |
143 | !IS_ALIGNED(node_end_pfn(nid), MAX_ORDER_NR_PAGES)) | |
144 | nr_pages += MAX_ORDER_NR_PAGES; | |
145 | ||
146 | table_size = sizeof(struct page_ext) * nr_pages; | |
147 | ||
148 | base = memblock_virt_alloc_try_nid_nopanic( | |
149 | table_size, PAGE_SIZE, __pa(MAX_DMA_ADDRESS), | |
150 | BOOTMEM_ALLOC_ACCESSIBLE, nid); | |
151 | if (!base) | |
152 | return -ENOMEM; | |
153 | NODE_DATA(nid)->node_page_ext = base; | |
154 | total_usage += table_size; | |
155 | return 0; | |
156 | } | |
157 | ||
158 | void __init page_ext_init_flatmem(void) | |
159 | { | |
160 | ||
161 | int nid, fail; | |
162 | ||
163 | if (!invoke_need_callbacks()) | |
164 | return; | |
165 | ||
166 | for_each_online_node(nid) { | |
167 | fail = alloc_node_page_ext(nid); | |
168 | if (fail) | |
169 | goto fail; | |
170 | } | |
171 | pr_info("allocated %ld bytes of page_ext\n", total_usage); | |
172 | invoke_init_callbacks(); | |
173 | return; | |
174 | ||
175 | fail: | |
176 | pr_crit("allocation of page_ext failed.\n"); | |
177 | panic("Out of memory"); | |
178 | } | |
179 | ||
180 | #else /* CONFIG_FLAT_NODE_MEM_MAP */ | |
181 | ||
182 | struct page_ext *lookup_page_ext(struct page *page) | |
183 | { | |
184 | unsigned long pfn = page_to_pfn(page); | |
185 | struct mem_section *section = __pfn_to_section(pfn); | |
1414c7f4 | 186 | #if defined(CONFIG_DEBUG_VM) || defined(CONFIG_PAGE_POISONING) |
eefa864b JK |
187 | /* |
188 | * The sanity checks the page allocator does upon freeing a | |
189 | * page can reach here before the page_ext arrays are | |
190 | * allocated when feeding a range of pages to the allocator | |
191 | * for the first time during bootup or memory hotplug. | |
1414c7f4 LA |
192 | * |
193 | * This check is also necessary for ensuring page poisoning | |
194 | * works as expected when enabled | |
eefa864b JK |
195 | */ |
196 | if (!section->page_ext) | |
197 | return NULL; | |
198 | #endif | |
199 | return section->page_ext + pfn; | |
200 | } | |
201 | ||
202 | static void *__meminit alloc_page_ext(size_t size, int nid) | |
203 | { | |
204 | gfp_t flags = GFP_KERNEL | __GFP_ZERO | __GFP_NOWARN; | |
205 | void *addr = NULL; | |
206 | ||
207 | addr = alloc_pages_exact_nid(nid, size, flags); | |
208 | if (addr) { | |
209 | kmemleak_alloc(addr, size, 1, flags); | |
210 | return addr; | |
211 | } | |
212 | ||
213 | if (node_state(nid, N_HIGH_MEMORY)) | |
214 | addr = vzalloc_node(size, nid); | |
215 | else | |
216 | addr = vzalloc(size); | |
217 | ||
218 | return addr; | |
219 | } | |
220 | ||
221 | static int __meminit init_section_page_ext(unsigned long pfn, int nid) | |
222 | { | |
223 | struct mem_section *section; | |
224 | struct page_ext *base; | |
225 | unsigned long table_size; | |
226 | ||
227 | section = __pfn_to_section(pfn); | |
228 | ||
229 | if (section->page_ext) | |
230 | return 0; | |
231 | ||
232 | table_size = sizeof(struct page_ext) * PAGES_PER_SECTION; | |
233 | base = alloc_page_ext(table_size, nid); | |
234 | ||
235 | /* | |
236 | * The value stored in section->page_ext is (base - pfn) | |
237 | * and it does not point to the memory block allocated above, | |
238 | * causing kmemleak false positives. | |
239 | */ | |
240 | kmemleak_not_leak(base); | |
241 | ||
242 | if (!base) { | |
243 | pr_err("page ext allocation failure\n"); | |
244 | return -ENOMEM; | |
245 | } | |
246 | ||
247 | /* | |
248 | * The passed "pfn" may not be aligned to SECTION. For the calculation | |
249 | * we need to apply a mask. | |
250 | */ | |
251 | pfn &= PAGE_SECTION_MASK; | |
252 | section->page_ext = base - pfn; | |
253 | total_usage += table_size; | |
254 | return 0; | |
255 | } | |
256 | #ifdef CONFIG_MEMORY_HOTPLUG | |
257 | static void free_page_ext(void *addr) | |
258 | { | |
259 | if (is_vmalloc_addr(addr)) { | |
260 | vfree(addr); | |
261 | } else { | |
262 | struct page *page = virt_to_page(addr); | |
263 | size_t table_size; | |
264 | ||
265 | table_size = sizeof(struct page_ext) * PAGES_PER_SECTION; | |
266 | ||
267 | BUG_ON(PageReserved(page)); | |
268 | free_pages_exact(addr, table_size); | |
269 | } | |
270 | } | |
271 | ||
272 | static void __free_page_ext(unsigned long pfn) | |
273 | { | |
274 | struct mem_section *ms; | |
275 | struct page_ext *base; | |
276 | ||
277 | ms = __pfn_to_section(pfn); | |
278 | if (!ms || !ms->page_ext) | |
279 | return; | |
280 | base = ms->page_ext + pfn; | |
281 | free_page_ext(base); | |
282 | ms->page_ext = NULL; | |
283 | } | |
284 | ||
285 | static int __meminit online_page_ext(unsigned long start_pfn, | |
286 | unsigned long nr_pages, | |
287 | int nid) | |
288 | { | |
289 | unsigned long start, end, pfn; | |
290 | int fail = 0; | |
291 | ||
292 | start = SECTION_ALIGN_DOWN(start_pfn); | |
293 | end = SECTION_ALIGN_UP(start_pfn + nr_pages); | |
294 | ||
295 | if (nid == -1) { | |
296 | /* | |
297 | * In this case, "nid" already exists and contains valid memory. | |
298 | * "start_pfn" passed to us is a pfn which is an arg for | |
299 | * online__pages(), and start_pfn should exist. | |
300 | */ | |
301 | nid = pfn_to_nid(start_pfn); | |
302 | VM_BUG_ON(!node_state(nid, N_ONLINE)); | |
303 | } | |
304 | ||
305 | for (pfn = start; !fail && pfn < end; pfn += PAGES_PER_SECTION) { | |
306 | if (!pfn_present(pfn)) | |
307 | continue; | |
308 | fail = init_section_page_ext(pfn, nid); | |
309 | } | |
310 | if (!fail) | |
311 | return 0; | |
312 | ||
313 | /* rollback */ | |
314 | for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) | |
315 | __free_page_ext(pfn); | |
316 | ||
317 | return -ENOMEM; | |
318 | } | |
319 | ||
320 | static int __meminit offline_page_ext(unsigned long start_pfn, | |
321 | unsigned long nr_pages, int nid) | |
322 | { | |
323 | unsigned long start, end, pfn; | |
324 | ||
325 | start = SECTION_ALIGN_DOWN(start_pfn); | |
326 | end = SECTION_ALIGN_UP(start_pfn + nr_pages); | |
327 | ||
328 | for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) | |
329 | __free_page_ext(pfn); | |
330 | return 0; | |
331 | ||
332 | } | |
333 | ||
334 | static int __meminit page_ext_callback(struct notifier_block *self, | |
335 | unsigned long action, void *arg) | |
336 | { | |
337 | struct memory_notify *mn = arg; | |
338 | int ret = 0; | |
339 | ||
340 | switch (action) { | |
341 | case MEM_GOING_ONLINE: | |
342 | ret = online_page_ext(mn->start_pfn, | |
343 | mn->nr_pages, mn->status_change_nid); | |
344 | break; | |
345 | case MEM_OFFLINE: | |
346 | offline_page_ext(mn->start_pfn, | |
347 | mn->nr_pages, mn->status_change_nid); | |
348 | break; | |
349 | case MEM_CANCEL_ONLINE: | |
350 | offline_page_ext(mn->start_pfn, | |
351 | mn->nr_pages, mn->status_change_nid); | |
352 | break; | |
353 | case MEM_GOING_OFFLINE: | |
354 | break; | |
355 | case MEM_ONLINE: | |
356 | case MEM_CANCEL_OFFLINE: | |
357 | break; | |
358 | } | |
359 | ||
360 | return notifier_from_errno(ret); | |
361 | } | |
362 | ||
363 | #endif | |
364 | ||
365 | void __init page_ext_init(void) | |
366 | { | |
367 | unsigned long pfn; | |
368 | int nid; | |
369 | ||
370 | if (!invoke_need_callbacks()) | |
371 | return; | |
372 | ||
373 | for_each_node_state(nid, N_MEMORY) { | |
374 | unsigned long start_pfn, end_pfn; | |
375 | ||
376 | start_pfn = node_start_pfn(nid); | |
377 | end_pfn = node_end_pfn(nid); | |
378 | /* | |
379 | * start_pfn and end_pfn may not be aligned to SECTION and the | |
380 | * page->flags of out of node pages are not initialized. So we | |
381 | * scan [start_pfn, the biggest section's pfn < end_pfn) here. | |
382 | */ | |
383 | for (pfn = start_pfn; pfn < end_pfn; | |
384 | pfn = ALIGN(pfn + 1, PAGES_PER_SECTION)) { | |
385 | ||
386 | if (!pfn_valid(pfn)) | |
387 | continue; | |
388 | /* | |
389 | * Nodes's pfns can be overlapping. | |
390 | * We know some arch can have a nodes layout such as | |
391 | * -------------pfn--------------> | |
392 | * N0 | N1 | N2 | N0 | N1 | N2|.... | |
fe53ca54 YS |
393 | * |
394 | * Take into account DEFERRED_STRUCT_PAGE_INIT. | |
eefa864b | 395 | */ |
fe53ca54 | 396 | if (early_pfn_to_nid(pfn) != nid) |
eefa864b JK |
397 | continue; |
398 | if (init_section_page_ext(pfn, nid)) | |
399 | goto oom; | |
400 | } | |
401 | } | |
402 | hotplug_memory_notifier(page_ext_callback, 0); | |
403 | pr_info("allocated %ld bytes of page_ext\n", total_usage); | |
404 | invoke_init_callbacks(); | |
405 | return; | |
406 | ||
407 | oom: | |
408 | panic("Out of memory"); | |
409 | } | |
410 | ||
411 | void __meminit pgdat_page_ext_init(struct pglist_data *pgdat) | |
412 | { | |
413 | } | |
414 | ||
415 | #endif |