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84af458b BK |
1 | /* |
2 | * Collaborative memory management interface. | |
3 | * | |
4 | * Copyright (C) 2008 IBM Corporation | |
5 | * Author(s): Brian King (brking@linux.vnet.ibm.com), | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or modify | |
8 | * it under the terms of the GNU General Public License as published by | |
9 | * the Free Software Foundation; either version 2 of the License, or | |
10 | * (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
20 | * | |
21 | */ | |
22 | ||
23 | #include <linux/ctype.h> | |
24 | #include <linux/delay.h> | |
25 | #include <linux/errno.h> | |
26 | #include <linux/fs.h> | |
5a0e3ad6 | 27 | #include <linux/gfp.h> |
84af458b BK |
28 | #include <linux/init.h> |
29 | #include <linux/kthread.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/oom.h> | |
fecba962 | 32 | #include <linux/reboot.h> |
84af458b BK |
33 | #include <linux/sched.h> |
34 | #include <linux/stringify.h> | |
35 | #include <linux/swap.h> | |
36 | #include <linux/sysdev.h> | |
37 | #include <asm/firmware.h> | |
38 | #include <asm/hvcall.h> | |
39 | #include <asm/mmu.h> | |
40 | #include <asm/pgalloc.h> | |
41 | #include <asm/uaccess.h> | |
14b8a76b | 42 | #include <linux/memory.h> |
84af458b BK |
43 | |
44 | #include "plpar_wrappers.h" | |
45 | ||
46 | #define CMM_DRIVER_VERSION "1.0.0" | |
47 | #define CMM_DEFAULT_DELAY 1 | |
14b8a76b | 48 | #define CMM_HOTPLUG_DELAY 5 |
84af458b BK |
49 | #define CMM_DEBUG 0 |
50 | #define CMM_DISABLE 0 | |
51 | #define CMM_OOM_KB 1024 | |
52 | #define CMM_MIN_MEM_MB 256 | |
53 | #define KB2PAGES(_p) ((_p)>>(PAGE_SHIFT-10)) | |
54 | #define PAGES2KB(_p) ((_p)<<(PAGE_SHIFT-10)) | |
14b8a76b RJ |
55 | /* |
56 | * The priority level tries to ensure that this notifier is called as | |
57 | * late as possible to reduce thrashing in the shared memory pool. | |
58 | */ | |
59 | #define CMM_MEM_HOTPLUG_PRI 1 | |
60 | #define CMM_MEM_ISOLATE_PRI 15 | |
84af458b BK |
61 | |
62 | static unsigned int delay = CMM_DEFAULT_DELAY; | |
14b8a76b | 63 | static unsigned int hotplug_delay = CMM_HOTPLUG_DELAY; |
84af458b BK |
64 | static unsigned int oom_kb = CMM_OOM_KB; |
65 | static unsigned int cmm_debug = CMM_DEBUG; | |
66 | static unsigned int cmm_disabled = CMM_DISABLE; | |
67 | static unsigned long min_mem_mb = CMM_MIN_MEM_MB; | |
68 | static struct sys_device cmm_sysdev; | |
69 | ||
70 | MODULE_AUTHOR("Brian King <brking@linux.vnet.ibm.com>"); | |
71 | MODULE_DESCRIPTION("IBM System p Collaborative Memory Manager"); | |
72 | MODULE_LICENSE("GPL"); | |
73 | MODULE_VERSION(CMM_DRIVER_VERSION); | |
74 | ||
75 | module_param_named(delay, delay, uint, S_IRUGO | S_IWUSR); | |
76 | MODULE_PARM_DESC(delay, "Delay (in seconds) between polls to query hypervisor paging requests. " | |
77 | "[Default=" __stringify(CMM_DEFAULT_DELAY) "]"); | |
14b8a76b RJ |
78 | module_param_named(hotplug_delay, hotplug_delay, uint, S_IRUGO | S_IWUSR); |
79 | MODULE_PARM_DESC(delay, "Delay (in seconds) after memory hotplug remove " | |
80 | "before loaning resumes. " | |
81 | "[Default=" __stringify(CMM_HOTPLUG_DELAY) "]"); | |
84af458b BK |
82 | module_param_named(oom_kb, oom_kb, uint, S_IRUGO | S_IWUSR); |
83 | MODULE_PARM_DESC(oom_kb, "Amount of memory in kb to free on OOM. " | |
84 | "[Default=" __stringify(CMM_OOM_KB) "]"); | |
85 | module_param_named(min_mem_mb, min_mem_mb, ulong, S_IRUGO | S_IWUSR); | |
86 | MODULE_PARM_DESC(min_mem_mb, "Minimum amount of memory (in MB) to not balloon. " | |
87 | "[Default=" __stringify(CMM_MIN_MEM_MB) "]"); | |
88 | module_param_named(debug, cmm_debug, uint, S_IRUGO | S_IWUSR); | |
89 | MODULE_PARM_DESC(debug, "Enable module debugging logging. Set to 1 to enable. " | |
90 | "[Default=" __stringify(CMM_DEBUG) "]"); | |
91 | ||
92 | #define CMM_NR_PAGES ((PAGE_SIZE - sizeof(void *) - sizeof(unsigned long)) / sizeof(unsigned long)) | |
93 | ||
94 | #define cmm_dbg(...) if (cmm_debug) { printk(KERN_INFO "cmm: "__VA_ARGS__); } | |
95 | ||
96 | struct cmm_page_array { | |
97 | struct cmm_page_array *next; | |
98 | unsigned long index; | |
99 | unsigned long page[CMM_NR_PAGES]; | |
100 | }; | |
101 | ||
102 | static unsigned long loaned_pages; | |
103 | static unsigned long loaned_pages_target; | |
104 | static unsigned long oom_freed_pages; | |
105 | ||
106 | static struct cmm_page_array *cmm_page_list; | |
107 | static DEFINE_SPINLOCK(cmm_lock); | |
108 | ||
14b8a76b RJ |
109 | static DEFINE_MUTEX(hotplug_mutex); |
110 | static int hotplug_occurred; /* protected by the hotplug mutex */ | |
111 | ||
84af458b BK |
112 | static struct task_struct *cmm_thread_ptr; |
113 | ||
114 | /** | |
115 | * cmm_alloc_pages - Allocate pages and mark them as loaned | |
116 | * @nr: number of pages to allocate | |
117 | * | |
118 | * Return value: | |
119 | * number of pages requested to be allocated which were not | |
120 | **/ | |
121 | static long cmm_alloc_pages(long nr) | |
122 | { | |
123 | struct cmm_page_array *pa, *npa; | |
124 | unsigned long addr; | |
125 | long rc; | |
126 | ||
127 | cmm_dbg("Begin request for %ld pages\n", nr); | |
128 | ||
129 | while (nr) { | |
14b8a76b RJ |
130 | /* Exit if a hotplug operation is in progress or occurred */ |
131 | if (mutex_trylock(&hotplug_mutex)) { | |
132 | if (hotplug_occurred) { | |
133 | mutex_unlock(&hotplug_mutex); | |
134 | break; | |
135 | } | |
136 | mutex_unlock(&hotplug_mutex); | |
137 | } else { | |
138 | break; | |
139 | } | |
140 | ||
84af458b BK |
141 | addr = __get_free_page(GFP_NOIO | __GFP_NOWARN | |
142 | __GFP_NORETRY | __GFP_NOMEMALLOC); | |
143 | if (!addr) | |
144 | break; | |
145 | spin_lock(&cmm_lock); | |
146 | pa = cmm_page_list; | |
147 | if (!pa || pa->index >= CMM_NR_PAGES) { | |
148 | /* Need a new page for the page list. */ | |
149 | spin_unlock(&cmm_lock); | |
14b8a76b RJ |
150 | npa = (struct cmm_page_array *)__get_free_page( |
151 | GFP_NOIO | __GFP_NOWARN | | |
152 | __GFP_NORETRY | __GFP_NOMEMALLOC); | |
84af458b | 153 | if (!npa) { |
5df72bf3 | 154 | pr_info("%s: Can not allocate new page list\n", __func__); |
84af458b BK |
155 | free_page(addr); |
156 | break; | |
157 | } | |
158 | spin_lock(&cmm_lock); | |
159 | pa = cmm_page_list; | |
160 | ||
161 | if (!pa || pa->index >= CMM_NR_PAGES) { | |
162 | npa->next = pa; | |
163 | npa->index = 0; | |
164 | pa = npa; | |
165 | cmm_page_list = pa; | |
166 | } else | |
167 | free_page((unsigned long) npa); | |
168 | } | |
169 | ||
170 | if ((rc = plpar_page_set_loaned(__pa(addr)))) { | |
5df72bf3 | 171 | pr_err("%s: Can not set page to loaned. rc=%ld\n", __func__, rc); |
84af458b BK |
172 | spin_unlock(&cmm_lock); |
173 | free_page(addr); | |
174 | break; | |
175 | } | |
176 | ||
177 | pa->page[pa->index++] = addr; | |
178 | loaned_pages++; | |
179 | totalram_pages--; | |
180 | spin_unlock(&cmm_lock); | |
181 | nr--; | |
182 | } | |
183 | ||
184 | cmm_dbg("End request with %ld pages unfulfilled\n", nr); | |
185 | return nr; | |
186 | } | |
187 | ||
188 | /** | |
189 | * cmm_free_pages - Free pages and mark them as active | |
190 | * @nr: number of pages to free | |
191 | * | |
192 | * Return value: | |
193 | * number of pages requested to be freed which were not | |
194 | **/ | |
195 | static long cmm_free_pages(long nr) | |
196 | { | |
197 | struct cmm_page_array *pa; | |
198 | unsigned long addr; | |
199 | ||
200 | cmm_dbg("Begin free of %ld pages.\n", nr); | |
201 | spin_lock(&cmm_lock); | |
202 | pa = cmm_page_list; | |
203 | while (nr) { | |
204 | if (!pa || pa->index <= 0) | |
205 | break; | |
206 | addr = pa->page[--pa->index]; | |
207 | ||
208 | if (pa->index == 0) { | |
209 | pa = pa->next; | |
210 | free_page((unsigned long) cmm_page_list); | |
211 | cmm_page_list = pa; | |
212 | } | |
213 | ||
214 | plpar_page_set_active(__pa(addr)); | |
215 | free_page(addr); | |
216 | loaned_pages--; | |
217 | nr--; | |
218 | totalram_pages++; | |
219 | } | |
220 | spin_unlock(&cmm_lock); | |
221 | cmm_dbg("End request with %ld pages unfulfilled\n", nr); | |
222 | return nr; | |
223 | } | |
224 | ||
225 | /** | |
226 | * cmm_oom_notify - OOM notifier | |
227 | * @self: notifier block struct | |
228 | * @dummy: not used | |
229 | * @parm: returned - number of pages freed | |
230 | * | |
231 | * Return value: | |
232 | * NOTIFY_OK | |
233 | **/ | |
234 | static int cmm_oom_notify(struct notifier_block *self, | |
235 | unsigned long dummy, void *parm) | |
236 | { | |
237 | unsigned long *freed = parm; | |
238 | long nr = KB2PAGES(oom_kb); | |
239 | ||
240 | cmm_dbg("OOM processing started\n"); | |
241 | nr = cmm_free_pages(nr); | |
242 | loaned_pages_target = loaned_pages; | |
243 | *freed += KB2PAGES(oom_kb) - nr; | |
244 | oom_freed_pages += KB2PAGES(oom_kb) - nr; | |
245 | cmm_dbg("OOM processing complete\n"); | |
246 | return NOTIFY_OK; | |
247 | } | |
248 | ||
249 | /** | |
250 | * cmm_get_mpp - Read memory performance parameters | |
251 | * | |
252 | * Makes hcall to query the current page loan request from the hypervisor. | |
253 | * | |
254 | * Return value: | |
255 | * nothing | |
256 | **/ | |
257 | static void cmm_get_mpp(void) | |
258 | { | |
259 | int rc; | |
260 | struct hvcall_mpp_data mpp_data; | |
8be8cf5b BK |
261 | signed long active_pages_target, page_loan_request, target; |
262 | signed long total_pages = totalram_pages + loaned_pages; | |
263 | signed long min_mem_pages = (min_mem_mb * 1024 * 1024) / PAGE_SIZE; | |
84af458b BK |
264 | |
265 | rc = h_get_mpp(&mpp_data); | |
266 | ||
267 | if (rc != H_SUCCESS) | |
268 | return; | |
269 | ||
270 | page_loan_request = div_s64((s64)mpp_data.loan_request, PAGE_SIZE); | |
8be8cf5b BK |
271 | target = page_loan_request + (signed long)loaned_pages; |
272 | ||
273 | if (target < 0 || total_pages < min_mem_pages) | |
274 | target = 0; | |
275 | ||
276 | if (target > oom_freed_pages) | |
277 | target -= oom_freed_pages; | |
84af458b | 278 | else |
8be8cf5b BK |
279 | target = 0; |
280 | ||
281 | active_pages_target = total_pages - target; | |
282 | ||
283 | if (min_mem_pages > active_pages_target) | |
284 | target = total_pages - min_mem_pages; | |
84af458b | 285 | |
8be8cf5b BK |
286 | if (target < 0) |
287 | target = 0; | |
84af458b | 288 | |
8be8cf5b | 289 | loaned_pages_target = target; |
84af458b BK |
290 | |
291 | cmm_dbg("delta = %ld, loaned = %lu, target = %lu, oom = %lu, totalram = %lu\n", | |
292 | page_loan_request, loaned_pages, loaned_pages_target, | |
293 | oom_freed_pages, totalram_pages); | |
294 | } | |
295 | ||
296 | static struct notifier_block cmm_oom_nb = { | |
297 | .notifier_call = cmm_oom_notify | |
298 | }; | |
299 | ||
300 | /** | |
301 | * cmm_thread - CMM task thread | |
302 | * @dummy: not used | |
303 | * | |
304 | * Return value: | |
305 | * 0 | |
306 | **/ | |
307 | static int cmm_thread(void *dummy) | |
308 | { | |
309 | unsigned long timeleft; | |
310 | ||
311 | while (1) { | |
312 | timeleft = msleep_interruptible(delay * 1000); | |
313 | ||
14b8a76b | 314 | if (kthread_should_stop() || timeleft) |
84af458b | 315 | break; |
14b8a76b RJ |
316 | |
317 | if (mutex_trylock(&hotplug_mutex)) { | |
318 | if (hotplug_occurred) { | |
319 | hotplug_occurred = 0; | |
320 | mutex_unlock(&hotplug_mutex); | |
321 | cmm_dbg("Hotplug operation has occurred, " | |
322 | "loaning activity suspended " | |
323 | "for %d seconds.\n", | |
324 | hotplug_delay); | |
325 | timeleft = msleep_interruptible(hotplug_delay * | |
326 | 1000); | |
327 | if (kthread_should_stop() || timeleft) | |
328 | break; | |
329 | continue; | |
330 | } | |
331 | mutex_unlock(&hotplug_mutex); | |
332 | } else { | |
333 | cmm_dbg("Hotplug operation in progress, activity " | |
334 | "suspended\n"); | |
335 | continue; | |
84af458b BK |
336 | } |
337 | ||
338 | cmm_get_mpp(); | |
339 | ||
340 | if (loaned_pages_target > loaned_pages) { | |
341 | if (cmm_alloc_pages(loaned_pages_target - loaned_pages)) | |
342 | loaned_pages_target = loaned_pages; | |
343 | } else if (loaned_pages_target < loaned_pages) | |
344 | cmm_free_pages(loaned_pages - loaned_pages_target); | |
345 | } | |
346 | return 0; | |
347 | } | |
348 | ||
349 | #define CMM_SHOW(name, format, args...) \ | |
3cee67f7 SR |
350 | static ssize_t show_##name(struct sys_device *dev, \ |
351 | struct sysdev_attribute *attr, \ | |
352 | char *buf) \ | |
84af458b BK |
353 | { \ |
354 | return sprintf(buf, format, ##args); \ | |
355 | } \ | |
356 | static SYSDEV_ATTR(name, S_IRUGO, show_##name, NULL) | |
357 | ||
358 | CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(loaned_pages)); | |
359 | CMM_SHOW(loaned_target_kb, "%lu\n", PAGES2KB(loaned_pages_target)); | |
360 | ||
3cee67f7 SR |
361 | static ssize_t show_oom_pages(struct sys_device *dev, |
362 | struct sysdev_attribute *attr, char *buf) | |
84af458b BK |
363 | { |
364 | return sprintf(buf, "%lu\n", PAGES2KB(oom_freed_pages)); | |
365 | } | |
366 | ||
367 | static ssize_t store_oom_pages(struct sys_device *dev, | |
3cee67f7 | 368 | struct sysdev_attribute *attr, |
84af458b BK |
369 | const char *buf, size_t count) |
370 | { | |
371 | unsigned long val = simple_strtoul (buf, NULL, 10); | |
372 | ||
373 | if (!capable(CAP_SYS_ADMIN)) | |
374 | return -EPERM; | |
375 | if (val != 0) | |
376 | return -EBADMSG; | |
377 | ||
378 | oom_freed_pages = 0; | |
379 | return count; | |
380 | } | |
381 | ||
382 | static SYSDEV_ATTR(oom_freed_kb, S_IWUSR| S_IRUGO, | |
383 | show_oom_pages, store_oom_pages); | |
384 | ||
385 | static struct sysdev_attribute *cmm_attrs[] = { | |
386 | &attr_loaned_kb, | |
387 | &attr_loaned_target_kb, | |
388 | &attr_oom_freed_kb, | |
389 | }; | |
390 | ||
391 | static struct sysdev_class cmm_sysdev_class = { | |
392 | .name = "cmm", | |
393 | }; | |
394 | ||
395 | /** | |
396 | * cmm_sysfs_register - Register with sysfs | |
397 | * | |
398 | * Return value: | |
399 | * 0 on success / other on failure | |
400 | **/ | |
401 | static int cmm_sysfs_register(struct sys_device *sysdev) | |
402 | { | |
403 | int i, rc; | |
404 | ||
405 | if ((rc = sysdev_class_register(&cmm_sysdev_class))) | |
406 | return rc; | |
407 | ||
408 | sysdev->id = 0; | |
409 | sysdev->cls = &cmm_sysdev_class; | |
410 | ||
411 | if ((rc = sysdev_register(sysdev))) | |
412 | goto class_unregister; | |
413 | ||
414 | for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++) { | |
415 | if ((rc = sysdev_create_file(sysdev, cmm_attrs[i]))) | |
416 | goto fail; | |
417 | } | |
418 | ||
419 | return 0; | |
420 | ||
421 | fail: | |
422 | while (--i >= 0) | |
423 | sysdev_remove_file(sysdev, cmm_attrs[i]); | |
424 | sysdev_unregister(sysdev); | |
425 | class_unregister: | |
426 | sysdev_class_unregister(&cmm_sysdev_class); | |
427 | return rc; | |
428 | } | |
429 | ||
430 | /** | |
431 | * cmm_unregister_sysfs - Unregister from sysfs | |
432 | * | |
433 | **/ | |
434 | static void cmm_unregister_sysfs(struct sys_device *sysdev) | |
435 | { | |
436 | int i; | |
437 | ||
438 | for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++) | |
439 | sysdev_remove_file(sysdev, cmm_attrs[i]); | |
440 | sysdev_unregister(sysdev); | |
441 | sysdev_class_unregister(&cmm_sysdev_class); | |
442 | } | |
443 | ||
fecba962 BK |
444 | /** |
445 | * cmm_reboot_notifier - Make sure pages are not still marked as "loaned" | |
446 | * | |
447 | **/ | |
448 | static int cmm_reboot_notifier(struct notifier_block *nb, | |
449 | unsigned long action, void *unused) | |
450 | { | |
451 | if (action == SYS_RESTART) { | |
452 | if (cmm_thread_ptr) | |
453 | kthread_stop(cmm_thread_ptr); | |
454 | cmm_thread_ptr = NULL; | |
455 | cmm_free_pages(loaned_pages); | |
456 | } | |
457 | return NOTIFY_DONE; | |
458 | } | |
459 | ||
460 | static struct notifier_block cmm_reboot_nb = { | |
461 | .notifier_call = cmm_reboot_notifier, | |
462 | }; | |
463 | ||
14b8a76b RJ |
464 | /** |
465 | * cmm_count_pages - Count the number of pages loaned in a particular range. | |
466 | * | |
467 | * @arg: memory_isolate_notify structure with address range and count | |
468 | * | |
469 | * Return value: | |
470 | * 0 on success | |
471 | **/ | |
472 | static unsigned long cmm_count_pages(void *arg) | |
473 | { | |
474 | struct memory_isolate_notify *marg = arg; | |
475 | struct cmm_page_array *pa; | |
476 | unsigned long start = (unsigned long)pfn_to_kaddr(marg->start_pfn); | |
477 | unsigned long end = start + (marg->nr_pages << PAGE_SHIFT); | |
478 | unsigned long idx; | |
479 | ||
480 | spin_lock(&cmm_lock); | |
481 | pa = cmm_page_list; | |
482 | while (pa) { | |
483 | if ((unsigned long)pa >= start && (unsigned long)pa < end) | |
484 | marg->pages_found++; | |
485 | for (idx = 0; idx < pa->index; idx++) | |
486 | if (pa->page[idx] >= start && pa->page[idx] < end) | |
487 | marg->pages_found++; | |
488 | pa = pa->next; | |
489 | } | |
490 | spin_unlock(&cmm_lock); | |
491 | return 0; | |
492 | } | |
493 | ||
494 | /** | |
495 | * cmm_memory_isolate_cb - Handle memory isolation notifier calls | |
496 | * @self: notifier block struct | |
497 | * @action: action to take | |
498 | * @arg: struct memory_isolate_notify data for handler | |
499 | * | |
500 | * Return value: | |
501 | * NOTIFY_OK or notifier error based on subfunction return value | |
502 | **/ | |
503 | static int cmm_memory_isolate_cb(struct notifier_block *self, | |
504 | unsigned long action, void *arg) | |
505 | { | |
506 | int ret = 0; | |
507 | ||
508 | if (action == MEM_ISOLATE_COUNT) | |
509 | ret = cmm_count_pages(arg); | |
510 | ||
511 | if (ret) | |
512 | ret = notifier_from_errno(ret); | |
513 | else | |
514 | ret = NOTIFY_OK; | |
515 | ||
516 | return ret; | |
517 | } | |
518 | ||
519 | static struct notifier_block cmm_mem_isolate_nb = { | |
520 | .notifier_call = cmm_memory_isolate_cb, | |
521 | .priority = CMM_MEM_ISOLATE_PRI | |
522 | }; | |
523 | ||
524 | /** | |
525 | * cmm_mem_going_offline - Unloan pages where memory is to be removed | |
526 | * @arg: memory_notify structure with page range to be offlined | |
527 | * | |
528 | * Return value: | |
529 | * 0 on success | |
530 | **/ | |
531 | static int cmm_mem_going_offline(void *arg) | |
532 | { | |
533 | struct memory_notify *marg = arg; | |
534 | unsigned long start_page = (unsigned long)pfn_to_kaddr(marg->start_pfn); | |
535 | unsigned long end_page = start_page + (marg->nr_pages << PAGE_SHIFT); | |
536 | struct cmm_page_array *pa_curr, *pa_last, *npa; | |
537 | unsigned long idx; | |
538 | unsigned long freed = 0; | |
539 | ||
540 | cmm_dbg("Memory going offline, searching 0x%lx (%ld pages).\n", | |
541 | start_page, marg->nr_pages); | |
542 | spin_lock(&cmm_lock); | |
543 | ||
544 | /* Search the page list for pages in the range to be offlined */ | |
545 | pa_last = pa_curr = cmm_page_list; | |
546 | while (pa_curr) { | |
547 | for (idx = (pa_curr->index - 1); (idx + 1) > 0; idx--) { | |
548 | if ((pa_curr->page[idx] < start_page) || | |
549 | (pa_curr->page[idx] >= end_page)) | |
550 | continue; | |
551 | ||
552 | plpar_page_set_active(__pa(pa_curr->page[idx])); | |
553 | free_page(pa_curr->page[idx]); | |
554 | freed++; | |
555 | loaned_pages--; | |
556 | totalram_pages++; | |
557 | pa_curr->page[idx] = pa_last->page[--pa_last->index]; | |
558 | if (pa_last->index == 0) { | |
559 | if (pa_curr == pa_last) | |
560 | pa_curr = pa_last->next; | |
561 | pa_last = pa_last->next; | |
562 | free_page((unsigned long)cmm_page_list); | |
563 | cmm_page_list = pa_last; | |
564 | continue; | |
565 | } | |
566 | } | |
567 | pa_curr = pa_curr->next; | |
568 | } | |
569 | ||
570 | /* Search for page list structures in the range to be offlined */ | |
571 | pa_last = NULL; | |
572 | pa_curr = cmm_page_list; | |
573 | while (pa_curr) { | |
574 | if (((unsigned long)pa_curr >= start_page) && | |
575 | ((unsigned long)pa_curr < end_page)) { | |
576 | npa = (struct cmm_page_array *)__get_free_page( | |
577 | GFP_NOIO | __GFP_NOWARN | | |
578 | __GFP_NORETRY | __GFP_NOMEMALLOC); | |
579 | if (!npa) { | |
580 | spin_unlock(&cmm_lock); | |
581 | cmm_dbg("Failed to allocate memory for list " | |
582 | "management. Memory hotplug " | |
583 | "failed.\n"); | |
584 | return ENOMEM; | |
585 | } | |
586 | memcpy(npa, pa_curr, PAGE_SIZE); | |
587 | if (pa_curr == cmm_page_list) | |
588 | cmm_page_list = npa; | |
589 | if (pa_last) | |
590 | pa_last->next = npa; | |
591 | free_page((unsigned long) pa_curr); | |
592 | freed++; | |
593 | pa_curr = npa; | |
594 | } | |
595 | ||
596 | pa_last = pa_curr; | |
597 | pa_curr = pa_curr->next; | |
598 | } | |
599 | ||
600 | spin_unlock(&cmm_lock); | |
601 | cmm_dbg("Released %ld pages in the search range.\n", freed); | |
602 | ||
603 | return 0; | |
604 | } | |
605 | ||
606 | /** | |
607 | * cmm_memory_cb - Handle memory hotplug notifier calls | |
608 | * @self: notifier block struct | |
609 | * @action: action to take | |
610 | * @arg: struct memory_notify data for handler | |
611 | * | |
612 | * Return value: | |
613 | * NOTIFY_OK or notifier error based on subfunction return value | |
614 | * | |
615 | **/ | |
616 | static int cmm_memory_cb(struct notifier_block *self, | |
617 | unsigned long action, void *arg) | |
618 | { | |
619 | int ret = 0; | |
620 | ||
621 | switch (action) { | |
622 | case MEM_GOING_OFFLINE: | |
623 | mutex_lock(&hotplug_mutex); | |
624 | hotplug_occurred = 1; | |
625 | ret = cmm_mem_going_offline(arg); | |
626 | break; | |
627 | case MEM_OFFLINE: | |
628 | case MEM_CANCEL_OFFLINE: | |
629 | mutex_unlock(&hotplug_mutex); | |
630 | cmm_dbg("Memory offline operation complete.\n"); | |
631 | break; | |
632 | case MEM_GOING_ONLINE: | |
633 | case MEM_ONLINE: | |
634 | case MEM_CANCEL_ONLINE: | |
635 | break; | |
636 | } | |
637 | ||
638 | if (ret) | |
639 | ret = notifier_from_errno(ret); | |
640 | else | |
641 | ret = NOTIFY_OK; | |
642 | ||
643 | return ret; | |
644 | } | |
645 | ||
646 | static struct notifier_block cmm_mem_nb = { | |
647 | .notifier_call = cmm_memory_cb, | |
648 | .priority = CMM_MEM_HOTPLUG_PRI | |
649 | }; | |
650 | ||
84af458b BK |
651 | /** |
652 | * cmm_init - Module initialization | |
653 | * | |
654 | * Return value: | |
655 | * 0 on success / other on failure | |
656 | **/ | |
657 | static int cmm_init(void) | |
658 | { | |
659 | int rc = -ENOMEM; | |
660 | ||
661 | if (!firmware_has_feature(FW_FEATURE_CMO)) | |
662 | return -EOPNOTSUPP; | |
663 | ||
664 | if ((rc = register_oom_notifier(&cmm_oom_nb)) < 0) | |
665 | return rc; | |
666 | ||
fecba962 | 667 | if ((rc = register_reboot_notifier(&cmm_reboot_nb))) |
84af458b BK |
668 | goto out_oom_notifier; |
669 | ||
fecba962 BK |
670 | if ((rc = cmm_sysfs_register(&cmm_sysdev))) |
671 | goto out_reboot_notifier; | |
672 | ||
14b8a76b RJ |
673 | if (register_memory_notifier(&cmm_mem_nb) || |
674 | register_memory_isolate_notifier(&cmm_mem_isolate_nb)) | |
675 | goto out_unregister_notifier; | |
676 | ||
84af458b BK |
677 | if (cmm_disabled) |
678 | return rc; | |
679 | ||
680 | cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); | |
681 | if (IS_ERR(cmm_thread_ptr)) { | |
682 | rc = PTR_ERR(cmm_thread_ptr); | |
14b8a76b | 683 | goto out_unregister_notifier; |
84af458b BK |
684 | } |
685 | ||
686 | return rc; | |
687 | ||
14b8a76b RJ |
688 | out_unregister_notifier: |
689 | unregister_memory_notifier(&cmm_mem_nb); | |
690 | unregister_memory_isolate_notifier(&cmm_mem_isolate_nb); | |
84af458b | 691 | cmm_unregister_sysfs(&cmm_sysdev); |
fecba962 BK |
692 | out_reboot_notifier: |
693 | unregister_reboot_notifier(&cmm_reboot_nb); | |
84af458b BK |
694 | out_oom_notifier: |
695 | unregister_oom_notifier(&cmm_oom_nb); | |
696 | return rc; | |
697 | } | |
698 | ||
699 | /** | |
700 | * cmm_exit - Module exit | |
701 | * | |
702 | * Return value: | |
703 | * nothing | |
704 | **/ | |
705 | static void cmm_exit(void) | |
706 | { | |
707 | if (cmm_thread_ptr) | |
708 | kthread_stop(cmm_thread_ptr); | |
709 | unregister_oom_notifier(&cmm_oom_nb); | |
fecba962 | 710 | unregister_reboot_notifier(&cmm_reboot_nb); |
14b8a76b RJ |
711 | unregister_memory_notifier(&cmm_mem_nb); |
712 | unregister_memory_isolate_notifier(&cmm_mem_isolate_nb); | |
84af458b BK |
713 | cmm_free_pages(loaned_pages); |
714 | cmm_unregister_sysfs(&cmm_sysdev); | |
715 | } | |
716 | ||
717 | /** | |
718 | * cmm_set_disable - Disable/Enable CMM | |
719 | * | |
720 | * Return value: | |
721 | * 0 on success / other on failure | |
722 | **/ | |
723 | static int cmm_set_disable(const char *val, struct kernel_param *kp) | |
724 | { | |
725 | int disable = simple_strtoul(val, NULL, 10); | |
726 | ||
727 | if (disable != 0 && disable != 1) | |
728 | return -EINVAL; | |
729 | ||
730 | if (disable && !cmm_disabled) { | |
731 | if (cmm_thread_ptr) | |
732 | kthread_stop(cmm_thread_ptr); | |
733 | cmm_thread_ptr = NULL; | |
734 | cmm_free_pages(loaned_pages); | |
735 | } else if (!disable && cmm_disabled) { | |
736 | cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); | |
737 | if (IS_ERR(cmm_thread_ptr)) | |
738 | return PTR_ERR(cmm_thread_ptr); | |
739 | } | |
740 | ||
741 | cmm_disabled = disable; | |
742 | return 0; | |
743 | } | |
744 | ||
745 | module_param_call(disable, cmm_set_disable, param_get_uint, | |
746 | &cmm_disabled, S_IRUGO | S_IWUSR); | |
747 | MODULE_PARM_DESC(disable, "Disable CMM. Set to 1 to disable. " | |
748 | "[Default=" __stringify(CMM_DISABLE) "]"); | |
749 | ||
750 | module_init(cmm_init); | |
751 | module_exit(cmm_exit); |