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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> | |
7c0f6ba6 | 40 | #include <linux/uaccess.h> |
14b8a76b | 41 | #include <linux/memory.h> |
212bebb4 | 42 | #include <asm/plpar_wrappers.h> |
84af458b | 43 | |
8f272a5d ME |
44 | #include "pseries.h" |
45 | ||
84af458b BK |
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; | |
6c9d2909 | 68 | static struct device cmm_dev; |
84af458b BK |
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 | ||
57ad583f | 75 | module_param_named(delay, delay, uint, 0644); |
84af458b BK |
76 | MODULE_PARM_DESC(delay, "Delay (in seconds) between polls to query hypervisor paging requests. " |
77 | "[Default=" __stringify(CMM_DEFAULT_DELAY) "]"); | |
57ad583f | 78 | module_param_named(hotplug_delay, hotplug_delay, uint, 0644); |
b0b5a765 | 79 | MODULE_PARM_DESC(hotplug_delay, "Delay (in seconds) after memory hotplug remove " |
14b8a76b RJ |
80 | "before loaning resumes. " |
81 | "[Default=" __stringify(CMM_HOTPLUG_DELAY) "]"); | |
57ad583f | 82 | module_param_named(oom_kb, oom_kb, uint, 0644); |
84af458b BK |
83 | MODULE_PARM_DESC(oom_kb, "Amount of memory in kb to free on OOM. " |
84 | "[Default=" __stringify(CMM_OOM_KB) "]"); | |
57ad583f | 85 | module_param_named(min_mem_mb, min_mem_mb, ulong, 0644); |
84af458b BK |
86 | MODULE_PARM_DESC(min_mem_mb, "Minimum amount of memory (in MB) to not balloon. " |
87 | "[Default=" __stringify(CMM_MIN_MEM_MB) "]"); | |
57ad583f | 88 | module_param_named(debug, cmm_debug, uint, 0644); |
84af458b BK |
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 | ||
8f272a5d ME |
114 | static long plpar_page_set_loaned(unsigned long vpa) |
115 | { | |
116 | unsigned long cmo_page_sz = cmo_get_page_size(); | |
117 | long rc = 0; | |
118 | int i; | |
119 | ||
120 | for (i = 0; !rc && i < PAGE_SIZE; i += cmo_page_sz) | |
121 | rc = plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_LOANED, vpa + i, 0); | |
122 | ||
123 | for (i -= cmo_page_sz; rc && i != 0; i -= cmo_page_sz) | |
124 | plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_ACTIVE, | |
125 | vpa + i - cmo_page_sz, 0); | |
126 | ||
127 | return rc; | |
128 | } | |
129 | ||
130 | static long plpar_page_set_active(unsigned long vpa) | |
131 | { | |
132 | unsigned long cmo_page_sz = cmo_get_page_size(); | |
133 | long rc = 0; | |
134 | int i; | |
135 | ||
136 | for (i = 0; !rc && i < PAGE_SIZE; i += cmo_page_sz) | |
137 | rc = plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_ACTIVE, vpa + i, 0); | |
138 | ||
139 | for (i -= cmo_page_sz; rc && i != 0; i -= cmo_page_sz) | |
140 | plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_LOANED, | |
141 | vpa + i - cmo_page_sz, 0); | |
142 | ||
143 | return rc; | |
144 | } | |
145 | ||
84af458b BK |
146 | /** |
147 | * cmm_alloc_pages - Allocate pages and mark them as loaned | |
148 | * @nr: number of pages to allocate | |
149 | * | |
150 | * Return value: | |
151 | * number of pages requested to be allocated which were not | |
152 | **/ | |
153 | static long cmm_alloc_pages(long nr) | |
154 | { | |
155 | struct cmm_page_array *pa, *npa; | |
156 | unsigned long addr; | |
157 | long rc; | |
158 | ||
159 | cmm_dbg("Begin request for %ld pages\n", nr); | |
160 | ||
161 | while (nr) { | |
14b8a76b RJ |
162 | /* Exit if a hotplug operation is in progress or occurred */ |
163 | if (mutex_trylock(&hotplug_mutex)) { | |
164 | if (hotplug_occurred) { | |
165 | mutex_unlock(&hotplug_mutex); | |
166 | break; | |
167 | } | |
168 | mutex_unlock(&hotplug_mutex); | |
169 | } else { | |
170 | break; | |
171 | } | |
172 | ||
84af458b BK |
173 | addr = __get_free_page(GFP_NOIO | __GFP_NOWARN | |
174 | __GFP_NORETRY | __GFP_NOMEMALLOC); | |
175 | if (!addr) | |
176 | break; | |
177 | spin_lock(&cmm_lock); | |
178 | pa = cmm_page_list; | |
179 | if (!pa || pa->index >= CMM_NR_PAGES) { | |
180 | /* Need a new page for the page list. */ | |
181 | spin_unlock(&cmm_lock); | |
14b8a76b RJ |
182 | npa = (struct cmm_page_array *)__get_free_page( |
183 | GFP_NOIO | __GFP_NOWARN | | |
184 | __GFP_NORETRY | __GFP_NOMEMALLOC); | |
84af458b | 185 | if (!npa) { |
5df72bf3 | 186 | pr_info("%s: Can not allocate new page list\n", __func__); |
84af458b BK |
187 | free_page(addr); |
188 | break; | |
189 | } | |
190 | spin_lock(&cmm_lock); | |
191 | pa = cmm_page_list; | |
192 | ||
193 | if (!pa || pa->index >= CMM_NR_PAGES) { | |
194 | npa->next = pa; | |
195 | npa->index = 0; | |
196 | pa = npa; | |
197 | cmm_page_list = pa; | |
198 | } else | |
199 | free_page((unsigned long) npa); | |
200 | } | |
201 | ||
202 | if ((rc = plpar_page_set_loaned(__pa(addr)))) { | |
5df72bf3 | 203 | pr_err("%s: Can not set page to loaned. rc=%ld\n", __func__, rc); |
84af458b BK |
204 | spin_unlock(&cmm_lock); |
205 | free_page(addr); | |
206 | break; | |
207 | } | |
208 | ||
209 | pa->page[pa->index++] = addr; | |
210 | loaned_pages++; | |
ca79b0c2 | 211 | totalram_pages_dec(); |
84af458b BK |
212 | spin_unlock(&cmm_lock); |
213 | nr--; | |
214 | } | |
215 | ||
216 | cmm_dbg("End request with %ld pages unfulfilled\n", nr); | |
217 | return nr; | |
218 | } | |
219 | ||
220 | /** | |
221 | * cmm_free_pages - Free pages and mark them as active | |
222 | * @nr: number of pages to free | |
223 | * | |
224 | * Return value: | |
225 | * number of pages requested to be freed which were not | |
226 | **/ | |
227 | static long cmm_free_pages(long nr) | |
228 | { | |
229 | struct cmm_page_array *pa; | |
230 | unsigned long addr; | |
231 | ||
232 | cmm_dbg("Begin free of %ld pages.\n", nr); | |
233 | spin_lock(&cmm_lock); | |
234 | pa = cmm_page_list; | |
235 | while (nr) { | |
236 | if (!pa || pa->index <= 0) | |
237 | break; | |
238 | addr = pa->page[--pa->index]; | |
239 | ||
240 | if (pa->index == 0) { | |
241 | pa = pa->next; | |
242 | free_page((unsigned long) cmm_page_list); | |
243 | cmm_page_list = pa; | |
244 | } | |
245 | ||
246 | plpar_page_set_active(__pa(addr)); | |
247 | free_page(addr); | |
248 | loaned_pages--; | |
249 | nr--; | |
ca79b0c2 | 250 | totalram_pages_inc(); |
84af458b BK |
251 | } |
252 | spin_unlock(&cmm_lock); | |
253 | cmm_dbg("End request with %ld pages unfulfilled\n", nr); | |
254 | return nr; | |
255 | } | |
256 | ||
257 | /** | |
258 | * cmm_oom_notify - OOM notifier | |
259 | * @self: notifier block struct | |
260 | * @dummy: not used | |
261 | * @parm: returned - number of pages freed | |
262 | * | |
263 | * Return value: | |
264 | * NOTIFY_OK | |
265 | **/ | |
266 | static int cmm_oom_notify(struct notifier_block *self, | |
267 | unsigned long dummy, void *parm) | |
268 | { | |
269 | unsigned long *freed = parm; | |
270 | long nr = KB2PAGES(oom_kb); | |
271 | ||
272 | cmm_dbg("OOM processing started\n"); | |
273 | nr = cmm_free_pages(nr); | |
274 | loaned_pages_target = loaned_pages; | |
275 | *freed += KB2PAGES(oom_kb) - nr; | |
276 | oom_freed_pages += KB2PAGES(oom_kb) - nr; | |
277 | cmm_dbg("OOM processing complete\n"); | |
278 | return NOTIFY_OK; | |
279 | } | |
280 | ||
281 | /** | |
282 | * cmm_get_mpp - Read memory performance parameters | |
283 | * | |
284 | * Makes hcall to query the current page loan request from the hypervisor. | |
285 | * | |
286 | * Return value: | |
287 | * nothing | |
288 | **/ | |
289 | static void cmm_get_mpp(void) | |
290 | { | |
291 | int rc; | |
292 | struct hvcall_mpp_data mpp_data; | |
8be8cf5b | 293 | signed long active_pages_target, page_loan_request, target; |
ca79b0c2 | 294 | signed long total_pages = totalram_pages() + loaned_pages; |
8be8cf5b | 295 | signed long min_mem_pages = (min_mem_mb * 1024 * 1024) / PAGE_SIZE; |
84af458b BK |
296 | |
297 | rc = h_get_mpp(&mpp_data); | |
298 | ||
299 | if (rc != H_SUCCESS) | |
300 | return; | |
301 | ||
302 | page_loan_request = div_s64((s64)mpp_data.loan_request, PAGE_SIZE); | |
8be8cf5b BK |
303 | target = page_loan_request + (signed long)loaned_pages; |
304 | ||
305 | if (target < 0 || total_pages < min_mem_pages) | |
306 | target = 0; | |
307 | ||
308 | if (target > oom_freed_pages) | |
309 | target -= oom_freed_pages; | |
84af458b | 310 | else |
8be8cf5b BK |
311 | target = 0; |
312 | ||
313 | active_pages_target = total_pages - target; | |
314 | ||
315 | if (min_mem_pages > active_pages_target) | |
316 | target = total_pages - min_mem_pages; | |
84af458b | 317 | |
8be8cf5b BK |
318 | if (target < 0) |
319 | target = 0; | |
84af458b | 320 | |
8be8cf5b | 321 | loaned_pages_target = target; |
84af458b BK |
322 | |
323 | cmm_dbg("delta = %ld, loaned = %lu, target = %lu, oom = %lu, totalram = %lu\n", | |
324 | page_loan_request, loaned_pages, loaned_pages_target, | |
ca79b0c2 | 325 | oom_freed_pages, totalram_pages()); |
84af458b BK |
326 | } |
327 | ||
328 | static struct notifier_block cmm_oom_nb = { | |
329 | .notifier_call = cmm_oom_notify | |
330 | }; | |
331 | ||
332 | /** | |
333 | * cmm_thread - CMM task thread | |
334 | * @dummy: not used | |
335 | * | |
336 | * Return value: | |
337 | * 0 | |
338 | **/ | |
339 | static int cmm_thread(void *dummy) | |
340 | { | |
341 | unsigned long timeleft; | |
342 | ||
343 | while (1) { | |
344 | timeleft = msleep_interruptible(delay * 1000); | |
345 | ||
14b8a76b | 346 | if (kthread_should_stop() || timeleft) |
84af458b | 347 | break; |
14b8a76b RJ |
348 | |
349 | if (mutex_trylock(&hotplug_mutex)) { | |
350 | if (hotplug_occurred) { | |
351 | hotplug_occurred = 0; | |
352 | mutex_unlock(&hotplug_mutex); | |
353 | cmm_dbg("Hotplug operation has occurred, " | |
354 | "loaning activity suspended " | |
355 | "for %d seconds.\n", | |
356 | hotplug_delay); | |
357 | timeleft = msleep_interruptible(hotplug_delay * | |
358 | 1000); | |
359 | if (kthread_should_stop() || timeleft) | |
360 | break; | |
361 | continue; | |
362 | } | |
363 | mutex_unlock(&hotplug_mutex); | |
364 | } else { | |
365 | cmm_dbg("Hotplug operation in progress, activity " | |
366 | "suspended\n"); | |
367 | continue; | |
84af458b BK |
368 | } |
369 | ||
370 | cmm_get_mpp(); | |
371 | ||
372 | if (loaned_pages_target > loaned_pages) { | |
373 | if (cmm_alloc_pages(loaned_pages_target - loaned_pages)) | |
374 | loaned_pages_target = loaned_pages; | |
375 | } else if (loaned_pages_target < loaned_pages) | |
376 | cmm_free_pages(loaned_pages - loaned_pages_target); | |
377 | } | |
378 | return 0; | |
379 | } | |
380 | ||
381 | #define CMM_SHOW(name, format, args...) \ | |
6c9d2909 KS |
382 | static ssize_t show_##name(struct device *dev, \ |
383 | struct device_attribute *attr, \ | |
3cee67f7 | 384 | char *buf) \ |
84af458b BK |
385 | { \ |
386 | return sprintf(buf, format, ##args); \ | |
387 | } \ | |
57ad583f | 388 | static DEVICE_ATTR(name, 0444, show_##name, NULL) |
84af458b BK |
389 | |
390 | CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(loaned_pages)); | |
391 | CMM_SHOW(loaned_target_kb, "%lu\n", PAGES2KB(loaned_pages_target)); | |
392 | ||
6c9d2909 KS |
393 | static ssize_t show_oom_pages(struct device *dev, |
394 | struct device_attribute *attr, char *buf) | |
84af458b BK |
395 | { |
396 | return sprintf(buf, "%lu\n", PAGES2KB(oom_freed_pages)); | |
397 | } | |
398 | ||
6c9d2909 KS |
399 | static ssize_t store_oom_pages(struct device *dev, |
400 | struct device_attribute *attr, | |
84af458b BK |
401 | const char *buf, size_t count) |
402 | { | |
403 | unsigned long val = simple_strtoul (buf, NULL, 10); | |
404 | ||
405 | if (!capable(CAP_SYS_ADMIN)) | |
406 | return -EPERM; | |
407 | if (val != 0) | |
408 | return -EBADMSG; | |
409 | ||
410 | oom_freed_pages = 0; | |
411 | return count; | |
412 | } | |
413 | ||
57ad583f | 414 | static DEVICE_ATTR(oom_freed_kb, 0644, |
84af458b BK |
415 | show_oom_pages, store_oom_pages); |
416 | ||
6c9d2909 KS |
417 | static struct device_attribute *cmm_attrs[] = { |
418 | &dev_attr_loaned_kb, | |
419 | &dev_attr_loaned_target_kb, | |
420 | &dev_attr_oom_freed_kb, | |
84af458b BK |
421 | }; |
422 | ||
6c9d2909 | 423 | static struct bus_type cmm_subsys = { |
84af458b | 424 | .name = "cmm", |
6c9d2909 | 425 | .dev_name = "cmm", |
84af458b BK |
426 | }; |
427 | ||
428 | /** | |
429 | * cmm_sysfs_register - Register with sysfs | |
430 | * | |
431 | * Return value: | |
432 | * 0 on success / other on failure | |
433 | **/ | |
6c9d2909 | 434 | static int cmm_sysfs_register(struct device *dev) |
84af458b BK |
435 | { |
436 | int i, rc; | |
437 | ||
6c9d2909 | 438 | if ((rc = subsys_system_register(&cmm_subsys, NULL))) |
84af458b BK |
439 | return rc; |
440 | ||
6c9d2909 KS |
441 | dev->id = 0; |
442 | dev->bus = &cmm_subsys; | |
84af458b | 443 | |
6c9d2909 KS |
444 | if ((rc = device_register(dev))) |
445 | goto subsys_unregister; | |
84af458b BK |
446 | |
447 | for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++) { | |
6c9d2909 | 448 | if ((rc = device_create_file(dev, cmm_attrs[i]))) |
84af458b BK |
449 | goto fail; |
450 | } | |
451 | ||
452 | return 0; | |
453 | ||
454 | fail: | |
455 | while (--i >= 0) | |
6c9d2909 KS |
456 | device_remove_file(dev, cmm_attrs[i]); |
457 | device_unregister(dev); | |
458 | subsys_unregister: | |
459 | bus_unregister(&cmm_subsys); | |
84af458b BK |
460 | return rc; |
461 | } | |
462 | ||
463 | /** | |
464 | * cmm_unregister_sysfs - Unregister from sysfs | |
465 | * | |
466 | **/ | |
6c9d2909 | 467 | static void cmm_unregister_sysfs(struct device *dev) |
84af458b BK |
468 | { |
469 | int i; | |
470 | ||
471 | for (i = 0; i < ARRAY_SIZE(cmm_attrs); i++) | |
6c9d2909 KS |
472 | device_remove_file(dev, cmm_attrs[i]); |
473 | device_unregister(dev); | |
474 | bus_unregister(&cmm_subsys); | |
84af458b BK |
475 | } |
476 | ||
fecba962 BK |
477 | /** |
478 | * cmm_reboot_notifier - Make sure pages are not still marked as "loaned" | |
479 | * | |
480 | **/ | |
481 | static int cmm_reboot_notifier(struct notifier_block *nb, | |
482 | unsigned long action, void *unused) | |
483 | { | |
484 | if (action == SYS_RESTART) { | |
485 | if (cmm_thread_ptr) | |
486 | kthread_stop(cmm_thread_ptr); | |
487 | cmm_thread_ptr = NULL; | |
488 | cmm_free_pages(loaned_pages); | |
489 | } | |
490 | return NOTIFY_DONE; | |
491 | } | |
492 | ||
493 | static struct notifier_block cmm_reboot_nb = { | |
494 | .notifier_call = cmm_reboot_notifier, | |
495 | }; | |
496 | ||
14b8a76b RJ |
497 | /** |
498 | * cmm_count_pages - Count the number of pages loaned in a particular range. | |
499 | * | |
500 | * @arg: memory_isolate_notify structure with address range and count | |
501 | * | |
502 | * Return value: | |
503 | * 0 on success | |
504 | **/ | |
505 | static unsigned long cmm_count_pages(void *arg) | |
506 | { | |
507 | struct memory_isolate_notify *marg = arg; | |
508 | struct cmm_page_array *pa; | |
509 | unsigned long start = (unsigned long)pfn_to_kaddr(marg->start_pfn); | |
510 | unsigned long end = start + (marg->nr_pages << PAGE_SHIFT); | |
511 | unsigned long idx; | |
512 | ||
513 | spin_lock(&cmm_lock); | |
514 | pa = cmm_page_list; | |
515 | while (pa) { | |
516 | if ((unsigned long)pa >= start && (unsigned long)pa < end) | |
517 | marg->pages_found++; | |
518 | for (idx = 0; idx < pa->index; idx++) | |
519 | if (pa->page[idx] >= start && pa->page[idx] < end) | |
520 | marg->pages_found++; | |
521 | pa = pa->next; | |
522 | } | |
523 | spin_unlock(&cmm_lock); | |
524 | return 0; | |
525 | } | |
526 | ||
527 | /** | |
528 | * cmm_memory_isolate_cb - Handle memory isolation notifier calls | |
529 | * @self: notifier block struct | |
530 | * @action: action to take | |
531 | * @arg: struct memory_isolate_notify data for handler | |
532 | * | |
533 | * Return value: | |
534 | * NOTIFY_OK or notifier error based on subfunction return value | |
535 | **/ | |
536 | static int cmm_memory_isolate_cb(struct notifier_block *self, | |
537 | unsigned long action, void *arg) | |
538 | { | |
539 | int ret = 0; | |
540 | ||
541 | if (action == MEM_ISOLATE_COUNT) | |
542 | ret = cmm_count_pages(arg); | |
543 | ||
7e26065d | 544 | return notifier_from_errno(ret); |
14b8a76b RJ |
545 | } |
546 | ||
547 | static struct notifier_block cmm_mem_isolate_nb = { | |
548 | .notifier_call = cmm_memory_isolate_cb, | |
549 | .priority = CMM_MEM_ISOLATE_PRI | |
550 | }; | |
551 | ||
552 | /** | |
553 | * cmm_mem_going_offline - Unloan pages where memory is to be removed | |
554 | * @arg: memory_notify structure with page range to be offlined | |
555 | * | |
556 | * Return value: | |
557 | * 0 on success | |
558 | **/ | |
559 | static int cmm_mem_going_offline(void *arg) | |
560 | { | |
561 | struct memory_notify *marg = arg; | |
562 | unsigned long start_page = (unsigned long)pfn_to_kaddr(marg->start_pfn); | |
563 | unsigned long end_page = start_page + (marg->nr_pages << PAGE_SHIFT); | |
564 | struct cmm_page_array *pa_curr, *pa_last, *npa; | |
565 | unsigned long idx; | |
566 | unsigned long freed = 0; | |
567 | ||
568 | cmm_dbg("Memory going offline, searching 0x%lx (%ld pages).\n", | |
569 | start_page, marg->nr_pages); | |
570 | spin_lock(&cmm_lock); | |
571 | ||
572 | /* Search the page list for pages in the range to be offlined */ | |
573 | pa_last = pa_curr = cmm_page_list; | |
574 | while (pa_curr) { | |
575 | for (idx = (pa_curr->index - 1); (idx + 1) > 0; idx--) { | |
576 | if ((pa_curr->page[idx] < start_page) || | |
577 | (pa_curr->page[idx] >= end_page)) | |
578 | continue; | |
579 | ||
580 | plpar_page_set_active(__pa(pa_curr->page[idx])); | |
581 | free_page(pa_curr->page[idx]); | |
582 | freed++; | |
583 | loaned_pages--; | |
ca79b0c2 | 584 | totalram_pages_inc(); |
14b8a76b RJ |
585 | pa_curr->page[idx] = pa_last->page[--pa_last->index]; |
586 | if (pa_last->index == 0) { | |
587 | if (pa_curr == pa_last) | |
588 | pa_curr = pa_last->next; | |
589 | pa_last = pa_last->next; | |
590 | free_page((unsigned long)cmm_page_list); | |
591 | cmm_page_list = pa_last; | |
14b8a76b RJ |
592 | } |
593 | } | |
594 | pa_curr = pa_curr->next; | |
595 | } | |
596 | ||
597 | /* Search for page list structures in the range to be offlined */ | |
598 | pa_last = NULL; | |
599 | pa_curr = cmm_page_list; | |
600 | while (pa_curr) { | |
601 | if (((unsigned long)pa_curr >= start_page) && | |
602 | ((unsigned long)pa_curr < end_page)) { | |
603 | npa = (struct cmm_page_array *)__get_free_page( | |
604 | GFP_NOIO | __GFP_NOWARN | | |
605 | __GFP_NORETRY | __GFP_NOMEMALLOC); | |
606 | if (!npa) { | |
607 | spin_unlock(&cmm_lock); | |
608 | cmm_dbg("Failed to allocate memory for list " | |
609 | "management. Memory hotplug " | |
610 | "failed.\n"); | |
e2be2371 | 611 | return -ENOMEM; |
14b8a76b RJ |
612 | } |
613 | memcpy(npa, pa_curr, PAGE_SIZE); | |
614 | if (pa_curr == cmm_page_list) | |
615 | cmm_page_list = npa; | |
616 | if (pa_last) | |
617 | pa_last->next = npa; | |
618 | free_page((unsigned long) pa_curr); | |
619 | freed++; | |
620 | pa_curr = npa; | |
621 | } | |
622 | ||
623 | pa_last = pa_curr; | |
624 | pa_curr = pa_curr->next; | |
625 | } | |
626 | ||
627 | spin_unlock(&cmm_lock); | |
628 | cmm_dbg("Released %ld pages in the search range.\n", freed); | |
629 | ||
630 | return 0; | |
631 | } | |
632 | ||
633 | /** | |
634 | * cmm_memory_cb - Handle memory hotplug notifier calls | |
635 | * @self: notifier block struct | |
636 | * @action: action to take | |
637 | * @arg: struct memory_notify data for handler | |
638 | * | |
639 | * Return value: | |
640 | * NOTIFY_OK or notifier error based on subfunction return value | |
641 | * | |
642 | **/ | |
643 | static int cmm_memory_cb(struct notifier_block *self, | |
644 | unsigned long action, void *arg) | |
645 | { | |
646 | int ret = 0; | |
647 | ||
648 | switch (action) { | |
649 | case MEM_GOING_OFFLINE: | |
650 | mutex_lock(&hotplug_mutex); | |
651 | hotplug_occurred = 1; | |
652 | ret = cmm_mem_going_offline(arg); | |
653 | break; | |
654 | case MEM_OFFLINE: | |
655 | case MEM_CANCEL_OFFLINE: | |
656 | mutex_unlock(&hotplug_mutex); | |
657 | cmm_dbg("Memory offline operation complete.\n"); | |
658 | break; | |
659 | case MEM_GOING_ONLINE: | |
660 | case MEM_ONLINE: | |
661 | case MEM_CANCEL_ONLINE: | |
662 | break; | |
663 | } | |
664 | ||
7e26065d | 665 | return notifier_from_errno(ret); |
14b8a76b RJ |
666 | } |
667 | ||
668 | static struct notifier_block cmm_mem_nb = { | |
669 | .notifier_call = cmm_memory_cb, | |
670 | .priority = CMM_MEM_HOTPLUG_PRI | |
671 | }; | |
672 | ||
84af458b BK |
673 | /** |
674 | * cmm_init - Module initialization | |
675 | * | |
676 | * Return value: | |
677 | * 0 on success / other on failure | |
678 | **/ | |
679 | static int cmm_init(void) | |
680 | { | |
681 | int rc = -ENOMEM; | |
682 | ||
683 | if (!firmware_has_feature(FW_FEATURE_CMO)) | |
684 | return -EOPNOTSUPP; | |
685 | ||
686 | if ((rc = register_oom_notifier(&cmm_oom_nb)) < 0) | |
687 | return rc; | |
688 | ||
fecba962 | 689 | if ((rc = register_reboot_notifier(&cmm_reboot_nb))) |
84af458b BK |
690 | goto out_oom_notifier; |
691 | ||
6c9d2909 | 692 | if ((rc = cmm_sysfs_register(&cmm_dev))) |
fecba962 BK |
693 | goto out_reboot_notifier; |
694 | ||
14b8a76b RJ |
695 | if (register_memory_notifier(&cmm_mem_nb) || |
696 | register_memory_isolate_notifier(&cmm_mem_isolate_nb)) | |
697 | goto out_unregister_notifier; | |
698 | ||
84af458b BK |
699 | if (cmm_disabled) |
700 | return rc; | |
701 | ||
702 | cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); | |
703 | if (IS_ERR(cmm_thread_ptr)) { | |
704 | rc = PTR_ERR(cmm_thread_ptr); | |
14b8a76b | 705 | goto out_unregister_notifier; |
84af458b BK |
706 | } |
707 | ||
708 | return rc; | |
709 | ||
14b8a76b RJ |
710 | out_unregister_notifier: |
711 | unregister_memory_notifier(&cmm_mem_nb); | |
712 | unregister_memory_isolate_notifier(&cmm_mem_isolate_nb); | |
6c9d2909 | 713 | cmm_unregister_sysfs(&cmm_dev); |
fecba962 BK |
714 | out_reboot_notifier: |
715 | unregister_reboot_notifier(&cmm_reboot_nb); | |
84af458b BK |
716 | out_oom_notifier: |
717 | unregister_oom_notifier(&cmm_oom_nb); | |
718 | return rc; | |
719 | } | |
720 | ||
721 | /** | |
722 | * cmm_exit - Module exit | |
723 | * | |
724 | * Return value: | |
725 | * nothing | |
726 | **/ | |
727 | static void cmm_exit(void) | |
728 | { | |
729 | if (cmm_thread_ptr) | |
730 | kthread_stop(cmm_thread_ptr); | |
731 | unregister_oom_notifier(&cmm_oom_nb); | |
fecba962 | 732 | unregister_reboot_notifier(&cmm_reboot_nb); |
14b8a76b RJ |
733 | unregister_memory_notifier(&cmm_mem_nb); |
734 | unregister_memory_isolate_notifier(&cmm_mem_isolate_nb); | |
84af458b | 735 | cmm_free_pages(loaned_pages); |
6c9d2909 | 736 | cmm_unregister_sysfs(&cmm_dev); |
84af458b BK |
737 | } |
738 | ||
739 | /** | |
740 | * cmm_set_disable - Disable/Enable CMM | |
741 | * | |
742 | * Return value: | |
743 | * 0 on success / other on failure | |
744 | **/ | |
e4dca7b7 | 745 | static int cmm_set_disable(const char *val, const struct kernel_param *kp) |
84af458b BK |
746 | { |
747 | int disable = simple_strtoul(val, NULL, 10); | |
748 | ||
749 | if (disable != 0 && disable != 1) | |
750 | return -EINVAL; | |
751 | ||
752 | if (disable && !cmm_disabled) { | |
753 | if (cmm_thread_ptr) | |
754 | kthread_stop(cmm_thread_ptr); | |
755 | cmm_thread_ptr = NULL; | |
756 | cmm_free_pages(loaned_pages); | |
757 | } else if (!disable && cmm_disabled) { | |
758 | cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread"); | |
759 | if (IS_ERR(cmm_thread_ptr)) | |
760 | return PTR_ERR(cmm_thread_ptr); | |
761 | } | |
762 | ||
763 | cmm_disabled = disable; | |
764 | return 0; | |
765 | } | |
766 | ||
767 | module_param_call(disable, cmm_set_disable, param_get_uint, | |
57ad583f | 768 | &cmm_disabled, 0644); |
84af458b BK |
769 | MODULE_PARM_DESC(disable, "Disable CMM. Set to 1 to disable. " |
770 | "[Default=" __stringify(CMM_DISABLE) "]"); | |
771 | ||
772 | module_init(cmm_init); | |
773 | module_exit(cmm_exit); |