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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/kthread.h> |
29 | #include <linux/module.h> | |
30 | #include <linux/oom.h> | |
fecba962 | 31 | #include <linux/reboot.h> |
84af458b BK |
32 | #include <linux/sched.h> |
33 | #include <linux/stringify.h> | |
34 | #include <linux/swap.h> | |
6c9d2909 | 35 | #include <linux/device.h> |
84af458b BK |
36 | #include <asm/firmware.h> |
37 | #include <asm/hvcall.h> | |
38 | #include <asm/mmu.h> | |
39 | #include <asm/pgalloc.h> | |
40 | #include <asm/uaccess.h> | |
14b8a76b | 41 | #include <linux/memory.h> |
212bebb4 | 42 | #include <asm/plpar_wrappers.h> |
84af458b BK |
43 | |
44 | #define CMM_DRIVER_VERSION "1.0.0" | |
45 | #define CMM_DEFAULT_DELAY 1 | |
14b8a76b | 46 | #define CMM_HOTPLUG_DELAY 5 |
84af458b BK |
47 | #define CMM_DEBUG 0 |
48 | #define CMM_DISABLE 0 | |
49 | #define CMM_OOM_KB 1024 | |
50 | #define CMM_MIN_MEM_MB 256 | |
51 | #define KB2PAGES(_p) ((_p)>>(PAGE_SHIFT-10)) | |
52 | #define PAGES2KB(_p) ((_p)<<(PAGE_SHIFT-10)) | |
14b8a76b RJ |
53 | /* |
54 | * The priority level tries to ensure that this notifier is called as | |
55 | * late as possible to reduce thrashing in the shared memory pool. | |
56 | */ | |
57 | #define CMM_MEM_HOTPLUG_PRI 1 | |
58 | #define CMM_MEM_ISOLATE_PRI 15 | |
84af458b BK |
59 | |
60 | static unsigned int delay = CMM_DEFAULT_DELAY; | |
14b8a76b | 61 | static unsigned int hotplug_delay = CMM_HOTPLUG_DELAY; |
84af458b BK |
62 | static unsigned int oom_kb = CMM_OOM_KB; |
63 | static unsigned int cmm_debug = CMM_DEBUG; | |
64 | static unsigned int cmm_disabled = CMM_DISABLE; | |
65 | static unsigned long min_mem_mb = CMM_MIN_MEM_MB; | |
6c9d2909 | 66 | static struct device cmm_dev; |
84af458b BK |
67 | |
68 | MODULE_AUTHOR("Brian King <brking@linux.vnet.ibm.com>"); | |
69 | MODULE_DESCRIPTION("IBM System p Collaborative Memory Manager"); | |
70 | MODULE_LICENSE("GPL"); | |
71 | MODULE_VERSION(CMM_DRIVER_VERSION); | |
72 | ||
73 | module_param_named(delay, delay, uint, S_IRUGO | S_IWUSR); | |
74 | MODULE_PARM_DESC(delay, "Delay (in seconds) between polls to query hypervisor paging requests. " | |
75 | "[Default=" __stringify(CMM_DEFAULT_DELAY) "]"); | |
14b8a76b RJ |
76 | module_param_named(hotplug_delay, hotplug_delay, uint, S_IRUGO | S_IWUSR); |
77 | MODULE_PARM_DESC(delay, "Delay (in seconds) after memory hotplug remove " | |
78 | "before loaning resumes. " | |
79 | "[Default=" __stringify(CMM_HOTPLUG_DELAY) "]"); | |
84af458b BK |
80 | module_param_named(oom_kb, oom_kb, uint, S_IRUGO | S_IWUSR); |
81 | MODULE_PARM_DESC(oom_kb, "Amount of memory in kb to free on OOM. " | |
82 | "[Default=" __stringify(CMM_OOM_KB) "]"); | |
83 | module_param_named(min_mem_mb, min_mem_mb, ulong, S_IRUGO | S_IWUSR); | |
84 | MODULE_PARM_DESC(min_mem_mb, "Minimum amount of memory (in MB) to not balloon. " | |
85 | "[Default=" __stringify(CMM_MIN_MEM_MB) "]"); | |
86 | module_param_named(debug, cmm_debug, uint, S_IRUGO | S_IWUSR); | |
87 | MODULE_PARM_DESC(debug, "Enable module debugging logging. Set to 1 to enable. " | |
88 | "[Default=" __stringify(CMM_DEBUG) "]"); | |
89 | ||
90 | #define CMM_NR_PAGES ((PAGE_SIZE - sizeof(void *) - sizeof(unsigned long)) / sizeof(unsigned long)) | |
91 | ||
92 | #define cmm_dbg(...) if (cmm_debug) { printk(KERN_INFO "cmm: "__VA_ARGS__); } | |
93 | ||
94 | struct cmm_page_array { | |
95 | struct cmm_page_array *next; | |
96 | unsigned long index; | |
97 | unsigned long page[CMM_NR_PAGES]; | |
98 | }; | |
99 | ||
100 | static unsigned long loaned_pages; | |
101 | static unsigned long loaned_pages_target; | |
102 | static unsigned long oom_freed_pages; | |
103 | ||
104 | static struct cmm_page_array *cmm_page_list; | |
105 | static DEFINE_SPINLOCK(cmm_lock); | |
106 | ||
14b8a76b RJ |
107 | static DEFINE_MUTEX(hotplug_mutex); |
108 | static int hotplug_occurred; /* protected by the hotplug mutex */ | |
109 | ||
84af458b BK |
110 | static struct task_struct *cmm_thread_ptr; |
111 | ||
112 | /** | |
113 | * cmm_alloc_pages - Allocate pages and mark them as loaned | |
114 | * @nr: number of pages to allocate | |
115 | * | |
116 | * Return value: | |
117 | * number of pages requested to be allocated which were not | |
118 | **/ | |
119 | static long cmm_alloc_pages(long nr) | |
120 | { | |
121 | struct cmm_page_array *pa, *npa; | |
122 | unsigned long addr; | |
123 | long rc; | |
124 | ||
125 | cmm_dbg("Begin request for %ld pages\n", nr); | |
126 | ||
127 | while (nr) { | |
14b8a76b RJ |
128 | /* Exit if a hotplug operation is in progress or occurred */ |
129 | if (mutex_trylock(&hotplug_mutex)) { | |
130 | if (hotplug_occurred) { | |
131 | mutex_unlock(&hotplug_mutex); | |
132 | break; | |
133 | } | |
134 | mutex_unlock(&hotplug_mutex); | |
135 | } else { | |
136 | break; | |
137 | } | |
138 | ||
84af458b BK |
139 | addr = __get_free_page(GFP_NOIO | __GFP_NOWARN | |
140 | __GFP_NORETRY | __GFP_NOMEMALLOC); | |
141 | if (!addr) | |
142 | break; | |
143 | spin_lock(&cmm_lock); | |
144 | pa = cmm_page_list; | |
145 | if (!pa || pa->index >= CMM_NR_PAGES) { | |
146 | /* Need a new page for the page list. */ | |
147 | spin_unlock(&cmm_lock); | |
14b8a76b RJ |
148 | npa = (struct cmm_page_array *)__get_free_page( |
149 | GFP_NOIO | __GFP_NOWARN | | |
150 | __GFP_NORETRY | __GFP_NOMEMALLOC); | |
84af458b | 151 | if (!npa) { |
5df72bf3 | 152 | pr_info("%s: Can not allocate new page list\n", __func__); |
84af458b BK |
153 | free_page(addr); |
154 | break; | |
155 | } | |
156 | spin_lock(&cmm_lock); | |
157 | pa = cmm_page_list; | |
158 | ||
159 | if (!pa || pa->index >= CMM_NR_PAGES) { | |
160 | npa->next = pa; | |
161 | npa->index = 0; | |
162 | pa = npa; | |
163 | cmm_page_list = pa; | |
164 | } else | |
165 | free_page((unsigned long) npa); | |
166 | } | |
167 | ||
168 | if ((rc = plpar_page_set_loaned(__pa(addr)))) { | |
5df72bf3 | 169 | pr_err("%s: Can not set page to loaned. rc=%ld\n", __func__, rc); |
84af458b BK |
170 | spin_unlock(&cmm_lock); |
171 | free_page(addr); | |
172 | break; | |
173 | } | |
174 | ||
175 | pa->page[pa->index++] = addr; | |
176 | loaned_pages++; | |
177 | totalram_pages--; | |
178 | spin_unlock(&cmm_lock); | |
179 | nr--; | |
180 | } | |
181 | ||
182 | cmm_dbg("End request with %ld pages unfulfilled\n", nr); | |
183 | return nr; | |
184 | } | |
185 | ||
186 | /** | |
187 | * cmm_free_pages - Free pages and mark them as active | |
188 | * @nr: number of pages to free | |
189 | * | |
190 | * Return value: | |
191 | * number of pages requested to be freed which were not | |
192 | **/ | |
193 | static long cmm_free_pages(long nr) | |
194 | { | |
195 | struct cmm_page_array *pa; | |
196 | unsigned long addr; | |
197 | ||
198 | cmm_dbg("Begin free of %ld pages.\n", nr); | |
199 | spin_lock(&cmm_lock); | |
200 | pa = cmm_page_list; | |
201 | while (nr) { | |
202 | if (!pa || pa->index <= 0) | |
203 | break; | |
204 | addr = pa->page[--pa->index]; | |
205 | ||
206 | if (pa->index == 0) { | |
207 | pa = pa->next; | |
208 | free_page((unsigned long) cmm_page_list); | |
209 | cmm_page_list = pa; | |
210 | } | |
211 | ||
212 | plpar_page_set_active(__pa(addr)); | |
213 | free_page(addr); | |
214 | loaned_pages--; | |
215 | nr--; | |
216 | totalram_pages++; | |
217 | } | |
218 | spin_unlock(&cmm_lock); | |
219 | cmm_dbg("End request with %ld pages unfulfilled\n", nr); | |
220 | return nr; | |
221 | } | |
222 | ||
223 | /** | |
224 | * cmm_oom_notify - OOM notifier | |
225 | * @self: notifier block struct | |
226 | * @dummy: not used | |
227 | * @parm: returned - number of pages freed | |
228 | * | |
229 | * Return value: | |
230 | * NOTIFY_OK | |
231 | **/ | |
232 | static int cmm_oom_notify(struct notifier_block *self, | |
233 | unsigned long dummy, void *parm) | |
234 | { | |
235 | unsigned long *freed = parm; | |
236 | long nr = KB2PAGES(oom_kb); | |
237 | ||
238 | cmm_dbg("OOM processing started\n"); | |
239 | nr = cmm_free_pages(nr); | |
240 | loaned_pages_target = loaned_pages; | |
241 | *freed += KB2PAGES(oom_kb) - nr; | |
242 | oom_freed_pages += KB2PAGES(oom_kb) - nr; | |
243 | cmm_dbg("OOM processing complete\n"); | |
244 | return NOTIFY_OK; | |
245 | } | |
246 | ||
247 | /** | |
248 | * cmm_get_mpp - Read memory performance parameters | |
249 | * | |
250 | * Makes hcall to query the current page loan request from the hypervisor. | |
251 | * | |
252 | * Return value: | |
253 | * nothing | |
254 | **/ | |
255 | static void cmm_get_mpp(void) | |
256 | { | |
257 | int rc; | |
258 | struct hvcall_mpp_data mpp_data; | |
8be8cf5b BK |
259 | signed long active_pages_target, page_loan_request, target; |
260 | signed long total_pages = totalram_pages + loaned_pages; | |
261 | signed long min_mem_pages = (min_mem_mb * 1024 * 1024) / PAGE_SIZE; | |
84af458b BK |
262 | |
263 | rc = h_get_mpp(&mpp_data); | |
264 | ||
265 | if (rc != H_SUCCESS) | |
266 | return; | |
267 | ||
268 | page_loan_request = div_s64((s64)mpp_data.loan_request, PAGE_SIZE); | |
8be8cf5b BK |
269 | target = page_loan_request + (signed long)loaned_pages; |
270 | ||
271 | if (target < 0 || total_pages < min_mem_pages) | |
272 | target = 0; | |
273 | ||
274 | if (target > oom_freed_pages) | |
275 | target -= oom_freed_pages; | |
84af458b | 276 | else |
8be8cf5b BK |
277 | target = 0; |
278 | ||
279 | active_pages_target = total_pages - target; | |
280 | ||
281 | if (min_mem_pages > active_pages_target) | |
282 | target = total_pages - min_mem_pages; | |
84af458b | 283 | |
8be8cf5b BK |
284 | if (target < 0) |
285 | target = 0; | |
84af458b | 286 | |
8be8cf5b | 287 | loaned_pages_target = target; |
84af458b BK |
288 | |
289 | cmm_dbg("delta = %ld, loaned = %lu, target = %lu, oom = %lu, totalram = %lu\n", | |
290 | page_loan_request, loaned_pages, loaned_pages_target, | |
291 | oom_freed_pages, totalram_pages); | |
292 | } | |
293 | ||
294 | static struct notifier_block cmm_oom_nb = { | |
295 | .notifier_call = cmm_oom_notify | |
296 | }; | |
297 | ||
298 | /** | |
299 | * cmm_thread - CMM task thread | |
300 | * @dummy: not used | |
301 | * | |
302 | * Return value: | |
303 | * 0 | |
304 | **/ | |
305 | static int cmm_thread(void *dummy) | |
306 | { | |
307 | unsigned long timeleft; | |
308 | ||
309 | while (1) { | |
310 | timeleft = msleep_interruptible(delay * 1000); | |
311 | ||
14b8a76b | 312 | if (kthread_should_stop() || timeleft) |
84af458b | 313 | break; |
14b8a76b RJ |
314 | |
315 | if (mutex_trylock(&hotplug_mutex)) { | |
316 | if (hotplug_occurred) { | |
317 | hotplug_occurred = 0; | |
318 | mutex_unlock(&hotplug_mutex); | |
319 | cmm_dbg("Hotplug operation has occurred, " | |
320 | "loaning activity suspended " | |
321 | "for %d seconds.\n", | |
322 | hotplug_delay); | |
323 | timeleft = msleep_interruptible(hotplug_delay * | |
324 | 1000); | |
325 | if (kthread_should_stop() || timeleft) | |
326 | break; | |
327 | continue; | |
328 | } | |
329 | mutex_unlock(&hotplug_mutex); | |
330 | } else { | |
331 | cmm_dbg("Hotplug operation in progress, activity " | |
332 | "suspended\n"); | |
333 | continue; | |
84af458b BK |
334 | } |
335 | ||
336 | cmm_get_mpp(); | |
337 | ||
338 | if (loaned_pages_target > loaned_pages) { | |
339 | if (cmm_alloc_pages(loaned_pages_target - loaned_pages)) | |
340 | loaned_pages_target = loaned_pages; | |
341 | } else if (loaned_pages_target < loaned_pages) | |
342 | cmm_free_pages(loaned_pages - loaned_pages_target); | |
343 | } | |
344 | return 0; | |
345 | } | |
346 | ||
347 | #define CMM_SHOW(name, format, args...) \ | |
6c9d2909 KS |
348 | static ssize_t show_##name(struct device *dev, \ |
349 | struct device_attribute *attr, \ | |
3cee67f7 | 350 | char *buf) \ |
84af458b BK |
351 | { \ |
352 | return sprintf(buf, format, ##args); \ | |
353 | } \ | |
6c9d2909 | 354 | static DEVICE_ATTR(name, S_IRUGO, show_##name, NULL) |
84af458b BK |
355 | |
356 | CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(loaned_pages)); | |
357 | CMM_SHOW(loaned_target_kb, "%lu\n", PAGES2KB(loaned_pages_target)); | |
358 | ||
6c9d2909 KS |
359 | static ssize_t show_oom_pages(struct device *dev, |
360 | struct device_attribute *attr, char *buf) | |
84af458b BK |
361 | { |
362 | return sprintf(buf, "%lu\n", PAGES2KB(oom_freed_pages)); | |
363 | } | |
364 | ||
6c9d2909 KS |
365 | static ssize_t store_oom_pages(struct device *dev, |
366 | struct device_attribute *attr, | |
84af458b BK |
367 | const char *buf, size_t count) |
368 | { | |
369 | unsigned long val = simple_strtoul (buf, NULL, 10); | |
370 | ||
371 | if (!capable(CAP_SYS_ADMIN)) | |
372 | return -EPERM; | |
373 | if (val != 0) | |
374 | return -EBADMSG; | |
375 | ||
376 | oom_freed_pages = 0; | |
377 | return count; | |
378 | } | |
379 | ||
6c9d2909 | 380 | static DEVICE_ATTR(oom_freed_kb, S_IWUSR | S_IRUGO, |
84af458b BK |
381 | show_oom_pages, store_oom_pages); |
382 | ||
6c9d2909 KS |
383 | static struct device_attribute *cmm_attrs[] = { |
384 | &dev_attr_loaned_kb, | |
385 | &dev_attr_loaned_target_kb, | |
386 | &dev_attr_oom_freed_kb, | |
84af458b BK |
387 | }; |
388 | ||
6c9d2909 | 389 | static struct bus_type cmm_subsys = { |
84af458b | 390 | .name = "cmm", |
6c9d2909 | 391 | .dev_name = "cmm", |
84af458b BK |
392 | }; |
393 | ||
394 | /** | |
395 | * cmm_sysfs_register - Register with sysfs | |
396 | * | |
397 | * Return value: | |
398 | * 0 on success / other on failure | |
399 | **/ | |
6c9d2909 | 400 | static int cmm_sysfs_register(struct device *dev) |
84af458b BK |
401 | { |
402 | int i, rc; | |
403 | ||
6c9d2909 | 404 | if ((rc = subsys_system_register(&cmm_subsys, NULL))) |
84af458b BK |
405 | return rc; |
406 | ||
6c9d2909 KS |
407 | dev->id = 0; |
408 | dev->bus = &cmm_subsys; | |
84af458b | 409 | |
6c9d2909 KS |
410 | if ((rc = device_register(dev))) |
411 | goto subsys_unregister; | |
84af458b BK |
412 | |
413 | for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++) { | |
6c9d2909 | 414 | if ((rc = device_create_file(dev, cmm_attrs[i]))) |
84af458b BK |
415 | goto fail; |
416 | } | |
417 | ||
418 | return 0; | |
419 | ||
420 | fail: | |
421 | while (--i >= 0) | |
6c9d2909 KS |
422 | device_remove_file(dev, cmm_attrs[i]); |
423 | device_unregister(dev); | |
424 | subsys_unregister: | |
425 | bus_unregister(&cmm_subsys); | |
84af458b BK |
426 | return rc; |
427 | } | |
428 | ||
429 | /** | |
430 | * cmm_unregister_sysfs - Unregister from sysfs | |
431 | * | |
432 | **/ | |
6c9d2909 | 433 | static void cmm_unregister_sysfs(struct device *dev) |
84af458b BK |
434 | { |
435 | int i; | |
436 | ||
437 | for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++) | |
6c9d2909 KS |
438 | device_remove_file(dev, cmm_attrs[i]); |
439 | device_unregister(dev); | |
440 | bus_unregister(&cmm_subsys); | |
84af458b BK |
441 | } |
442 | ||
fecba962 BK |
443 | /** |
444 | * cmm_reboot_notifier - Make sure pages are not still marked as "loaned" | |
445 | * | |
446 | **/ | |
447 | static int cmm_reboot_notifier(struct notifier_block *nb, | |
448 | unsigned long action, void *unused) | |
449 | { | |
450 | if (action == SYS_RESTART) { | |
451 | if (cmm_thread_ptr) | |
452 | kthread_stop(cmm_thread_ptr); | |
453 | cmm_thread_ptr = NULL; | |
454 | cmm_free_pages(loaned_pages); | |
455 | } | |
456 | return NOTIFY_DONE; | |
457 | } | |
458 | ||
459 | static struct notifier_block cmm_reboot_nb = { | |
460 | .notifier_call = cmm_reboot_notifier, | |
461 | }; | |
462 | ||
14b8a76b RJ |
463 | /** |
464 | * cmm_count_pages - Count the number of pages loaned in a particular range. | |
465 | * | |
466 | * @arg: memory_isolate_notify structure with address range and count | |
467 | * | |
468 | * Return value: | |
469 | * 0 on success | |
470 | **/ | |
471 | static unsigned long cmm_count_pages(void *arg) | |
472 | { | |
473 | struct memory_isolate_notify *marg = arg; | |
474 | struct cmm_page_array *pa; | |
475 | unsigned long start = (unsigned long)pfn_to_kaddr(marg->start_pfn); | |
476 | unsigned long end = start + (marg->nr_pages << PAGE_SHIFT); | |
477 | unsigned long idx; | |
478 | ||
479 | spin_lock(&cmm_lock); | |
480 | pa = cmm_page_list; | |
481 | while (pa) { | |
482 | if ((unsigned long)pa >= start && (unsigned long)pa < end) | |
483 | marg->pages_found++; | |
484 | for (idx = 0; idx < pa->index; idx++) | |
485 | if (pa->page[idx] >= start && pa->page[idx] < end) | |
486 | marg->pages_found++; | |
487 | pa = pa->next; | |
488 | } | |
489 | spin_unlock(&cmm_lock); | |
490 | return 0; | |
491 | } | |
492 | ||
493 | /** | |
494 | * cmm_memory_isolate_cb - Handle memory isolation notifier calls | |
495 | * @self: notifier block struct | |
496 | * @action: action to take | |
497 | * @arg: struct memory_isolate_notify data for handler | |
498 | * | |
499 | * Return value: | |
500 | * NOTIFY_OK or notifier error based on subfunction return value | |
501 | **/ | |
502 | static int cmm_memory_isolate_cb(struct notifier_block *self, | |
503 | unsigned long action, void *arg) | |
504 | { | |
505 | int ret = 0; | |
506 | ||
507 | if (action == MEM_ISOLATE_COUNT) | |
508 | ret = cmm_count_pages(arg); | |
509 | ||
7e26065d | 510 | return notifier_from_errno(ret); |
14b8a76b RJ |
511 | } |
512 | ||
513 | static struct notifier_block cmm_mem_isolate_nb = { | |
514 | .notifier_call = cmm_memory_isolate_cb, | |
515 | .priority = CMM_MEM_ISOLATE_PRI | |
516 | }; | |
517 | ||
518 | /** | |
519 | * cmm_mem_going_offline - Unloan pages where memory is to be removed | |
520 | * @arg: memory_notify structure with page range to be offlined | |
521 | * | |
522 | * Return value: | |
523 | * 0 on success | |
524 | **/ | |
525 | static int cmm_mem_going_offline(void *arg) | |
526 | { | |
527 | struct memory_notify *marg = arg; | |
528 | unsigned long start_page = (unsigned long)pfn_to_kaddr(marg->start_pfn); | |
529 | unsigned long end_page = start_page + (marg->nr_pages << PAGE_SHIFT); | |
530 | struct cmm_page_array *pa_curr, *pa_last, *npa; | |
531 | unsigned long idx; | |
532 | unsigned long freed = 0; | |
533 | ||
534 | cmm_dbg("Memory going offline, searching 0x%lx (%ld pages).\n", | |
535 | start_page, marg->nr_pages); | |
536 | spin_lock(&cmm_lock); | |
537 | ||
538 | /* Search the page list for pages in the range to be offlined */ | |
539 | pa_last = pa_curr = cmm_page_list; | |
540 | while (pa_curr) { | |
541 | for (idx = (pa_curr->index - 1); (idx + 1) > 0; idx--) { | |
542 | if ((pa_curr->page[idx] < start_page) || | |
543 | (pa_curr->page[idx] >= end_page)) | |
544 | continue; | |
545 | ||
546 | plpar_page_set_active(__pa(pa_curr->page[idx])); | |
547 | free_page(pa_curr->page[idx]); | |
548 | freed++; | |
549 | loaned_pages--; | |
550 | totalram_pages++; | |
551 | pa_curr->page[idx] = pa_last->page[--pa_last->index]; | |
552 | if (pa_last->index == 0) { | |
553 | if (pa_curr == pa_last) | |
554 | pa_curr = pa_last->next; | |
555 | pa_last = pa_last->next; | |
556 | free_page((unsigned long)cmm_page_list); | |
557 | cmm_page_list = pa_last; | |
14b8a76b RJ |
558 | } |
559 | } | |
560 | pa_curr = pa_curr->next; | |
561 | } | |
562 | ||
563 | /* Search for page list structures in the range to be offlined */ | |
564 | pa_last = NULL; | |
565 | pa_curr = cmm_page_list; | |
566 | while (pa_curr) { | |
567 | if (((unsigned long)pa_curr >= start_page) && | |
568 | ((unsigned long)pa_curr < end_page)) { | |
569 | npa = (struct cmm_page_array *)__get_free_page( | |
570 | GFP_NOIO | __GFP_NOWARN | | |
571 | __GFP_NORETRY | __GFP_NOMEMALLOC); | |
572 | if (!npa) { | |
573 | spin_unlock(&cmm_lock); | |
574 | cmm_dbg("Failed to allocate memory for list " | |
575 | "management. Memory hotplug " | |
576 | "failed.\n"); | |
577 | return ENOMEM; | |
578 | } | |
579 | memcpy(npa, pa_curr, PAGE_SIZE); | |
580 | if (pa_curr == cmm_page_list) | |
581 | cmm_page_list = npa; | |
582 | if (pa_last) | |
583 | pa_last->next = npa; | |
584 | free_page((unsigned long) pa_curr); | |
585 | freed++; | |
586 | pa_curr = npa; | |
587 | } | |
588 | ||
589 | pa_last = pa_curr; | |
590 | pa_curr = pa_curr->next; | |
591 | } | |
592 | ||
593 | spin_unlock(&cmm_lock); | |
594 | cmm_dbg("Released %ld pages in the search range.\n", freed); | |
595 | ||
596 | return 0; | |
597 | } | |
598 | ||
599 | /** | |
600 | * cmm_memory_cb - Handle memory hotplug notifier calls | |
601 | * @self: notifier block struct | |
602 | * @action: action to take | |
603 | * @arg: struct memory_notify data for handler | |
604 | * | |
605 | * Return value: | |
606 | * NOTIFY_OK or notifier error based on subfunction return value | |
607 | * | |
608 | **/ | |
609 | static int cmm_memory_cb(struct notifier_block *self, | |
610 | unsigned long action, void *arg) | |
611 | { | |
612 | int ret = 0; | |
613 | ||
614 | switch (action) { | |
615 | case MEM_GOING_OFFLINE: | |
616 | mutex_lock(&hotplug_mutex); | |
617 | hotplug_occurred = 1; | |
618 | ret = cmm_mem_going_offline(arg); | |
619 | break; | |
620 | case MEM_OFFLINE: | |
621 | case MEM_CANCEL_OFFLINE: | |
622 | mutex_unlock(&hotplug_mutex); | |
623 | cmm_dbg("Memory offline operation complete.\n"); | |
624 | break; | |
625 | case MEM_GOING_ONLINE: | |
626 | case MEM_ONLINE: | |
627 | case MEM_CANCEL_ONLINE: | |
628 | break; | |
629 | } | |
630 | ||
7e26065d | 631 | return notifier_from_errno(ret); |
14b8a76b RJ |
632 | } |
633 | ||
634 | static struct notifier_block cmm_mem_nb = { | |
635 | .notifier_call = cmm_memory_cb, | |
636 | .priority = CMM_MEM_HOTPLUG_PRI | |
637 | }; | |
638 | ||
84af458b BK |
639 | /** |
640 | * cmm_init - Module initialization | |
641 | * | |
642 | * Return value: | |
643 | * 0 on success / other on failure | |
644 | **/ | |
645 | static int cmm_init(void) | |
646 | { | |
647 | int rc = -ENOMEM; | |
648 | ||
649 | if (!firmware_has_feature(FW_FEATURE_CMO)) | |
650 | return -EOPNOTSUPP; | |
651 | ||
652 | if ((rc = register_oom_notifier(&cmm_oom_nb)) < 0) | |
653 | return rc; | |
654 | ||
fecba962 | 655 | if ((rc = register_reboot_notifier(&cmm_reboot_nb))) |
84af458b BK |
656 | goto out_oom_notifier; |
657 | ||
6c9d2909 | 658 | if ((rc = cmm_sysfs_register(&cmm_dev))) |
fecba962 BK |
659 | goto out_reboot_notifier; |
660 | ||
14b8a76b RJ |
661 | if (register_memory_notifier(&cmm_mem_nb) || |
662 | register_memory_isolate_notifier(&cmm_mem_isolate_nb)) | |
663 | goto out_unregister_notifier; | |
664 | ||
84af458b BK |
665 | if (cmm_disabled) |
666 | return rc; | |
667 | ||
668 | cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); | |
669 | if (IS_ERR(cmm_thread_ptr)) { | |
670 | rc = PTR_ERR(cmm_thread_ptr); | |
14b8a76b | 671 | goto out_unregister_notifier; |
84af458b BK |
672 | } |
673 | ||
674 | return rc; | |
675 | ||
14b8a76b RJ |
676 | out_unregister_notifier: |
677 | unregister_memory_notifier(&cmm_mem_nb); | |
678 | unregister_memory_isolate_notifier(&cmm_mem_isolate_nb); | |
6c9d2909 | 679 | cmm_unregister_sysfs(&cmm_dev); |
fecba962 BK |
680 | out_reboot_notifier: |
681 | unregister_reboot_notifier(&cmm_reboot_nb); | |
84af458b BK |
682 | out_oom_notifier: |
683 | unregister_oom_notifier(&cmm_oom_nb); | |
684 | return rc; | |
685 | } | |
686 | ||
687 | /** | |
688 | * cmm_exit - Module exit | |
689 | * | |
690 | * Return value: | |
691 | * nothing | |
692 | **/ | |
693 | static void cmm_exit(void) | |
694 | { | |
695 | if (cmm_thread_ptr) | |
696 | kthread_stop(cmm_thread_ptr); | |
697 | unregister_oom_notifier(&cmm_oom_nb); | |
fecba962 | 698 | unregister_reboot_notifier(&cmm_reboot_nb); |
14b8a76b RJ |
699 | unregister_memory_notifier(&cmm_mem_nb); |
700 | unregister_memory_isolate_notifier(&cmm_mem_isolate_nb); | |
84af458b | 701 | cmm_free_pages(loaned_pages); |
6c9d2909 | 702 | cmm_unregister_sysfs(&cmm_dev); |
84af458b BK |
703 | } |
704 | ||
705 | /** | |
706 | * cmm_set_disable - Disable/Enable CMM | |
707 | * | |
708 | * Return value: | |
709 | * 0 on success / other on failure | |
710 | **/ | |
711 | static int cmm_set_disable(const char *val, struct kernel_param *kp) | |
712 | { | |
713 | int disable = simple_strtoul(val, NULL, 10); | |
714 | ||
715 | if (disable != 0 && disable != 1) | |
716 | return -EINVAL; | |
717 | ||
718 | if (disable && !cmm_disabled) { | |
719 | if (cmm_thread_ptr) | |
720 | kthread_stop(cmm_thread_ptr); | |
721 | cmm_thread_ptr = NULL; | |
722 | cmm_free_pages(loaned_pages); | |
723 | } else if (!disable && cmm_disabled) { | |
724 | cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); | |
725 | if (IS_ERR(cmm_thread_ptr)) | |
726 | return PTR_ERR(cmm_thread_ptr); | |
727 | } | |
728 | ||
729 | cmm_disabled = disable; | |
730 | return 0; | |
731 | } | |
732 | ||
733 | module_param_call(disable, cmm_set_disable, param_get_uint, | |
734 | &cmm_disabled, S_IRUGO | S_IWUSR); | |
735 | MODULE_PARM_DESC(disable, "Disable CMM. Set to 1 to disable. " | |
736 | "[Default=" __stringify(CMM_DISABLE) "]"); | |
737 | ||
738 | module_init(cmm_init); | |
739 | module_exit(cmm_exit); |