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2024-10-12 a5969cabbb4660eab42b6ef0412cbbd1200cf14d 
 kernel/arch/powerpc/platforms/pseries/cmm.c
....@@ -1,23 +1,9 @@
1
+// SPDX-License-Identifier: GPL-2.0-or-later
12 /*
23  * Collaborative memory management interface.
34  *
45  * Copyright (C) 2008 IBM Corporation
56  * 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
- *
217  */
228 
239 #include <linux/ctype.h>
....@@ -33,10 +19,13 @@
3319 #include <linux/stringify.h>
3420 #include <linux/swap.h>
3521 #include <linux/device.h>
22
+#include <linux/mount.h>
23
+#include <linux/pseudo_fs.h>
24
+#include <linux/magic.h>
25
+#include <linux/balloon_compaction.h>
3626 #include <asm/firmware.h>
3727 #include <asm/hvcall.h>
3828 #include <asm/mmu.h>
39
-#include <asm/pgalloc.h>
4029 #include <linux/uaccess.h>
4130 #include <linux/memory.h>
4231 #include <asm/plpar_wrappers.h>
....@@ -52,12 +41,8 @@
5241 #define CMM_MIN_MEM_MB		256
5342 #define KB2PAGES(_p)		((_p)>>(PAGE_SHIFT-10))
5443 #define PAGES2KB(_p)		((_p)<<(PAGE_SHIFT-10))
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
- */
44
+
5945 #define CMM_MEM_HOTPLUG_PRI	1
60
-#define CMM_MEM_ISOLATE_PRI	15
6146 
6247 static unsigned int delay = CMM_DEFAULT_DELAY;
6348 static unsigned int hotplug_delay = CMM_HOTPLUG_DELAY;
....@@ -65,6 +50,8 @@
6550 static unsigned int cmm_debug = CMM_DEBUG;
6651 static unsigned int cmm_disabled = CMM_DISABLE;
6752 static unsigned long min_mem_mb = CMM_MIN_MEM_MB;
53
+static bool __read_mostly simulate;
54
+static unsigned long simulate_loan_target_kb;
6855 static struct device cmm_dev;
6956 
7057 MODULE_AUTHOR("Brian King <brking@linux.vnet.ibm.com>");
....@@ -88,34 +75,30 @@
8875 module_param_named(debug, cmm_debug, uint, 0644);
8976 MODULE_PARM_DESC(debug, "Enable module debugging logging. Set to 1 to enable. "
9077 		 "[Default=" __stringify(CMM_DEBUG) "]");
91
-
92
-#define CMM_NR_PAGES ((PAGE_SIZE - sizeof(void *) - sizeof(unsigned long)) / sizeof(unsigned long))
78
+module_param_named(simulate, simulate, bool, 0444);
79
+MODULE_PARM_DESC(simulate, "Enable simulation mode (no communication with hw).");
9380 
9481 #define cmm_dbg(...) if (cmm_debug) { printk(KERN_INFO "cmm: "__VA_ARGS__); }
9582 
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;
83
+static atomic_long_t loaned_pages;
10384 static unsigned long loaned_pages_target;
10485 static unsigned long oom_freed_pages;
105
-
106
-static struct cmm_page_array *cmm_page_list;
107
-static DEFINE_SPINLOCK(cmm_lock);
10886 
10987 static DEFINE_MUTEX(hotplug_mutex);
11088 static int hotplug_occurred; /* protected by the hotplug mutex */
11189 
11290 static struct task_struct *cmm_thread_ptr;
91
+static struct balloon_dev_info b_dev_info;
11392 
114
-static long plpar_page_set_loaned(unsigned long vpa)
93
+static long plpar_page_set_loaned(struct page *page)
11594 {
95
+	const unsigned long vpa = page_to_phys(page);
11696 	unsigned long cmo_page_sz = cmo_get_page_size();
11797 	long rc = 0;
11898 	int i;
99
+
100
+	if (unlikely(simulate))
101
+		return 0;
119102 
120103 	for (i = 0; !rc && i < PAGE_SIZE; i += cmo_page_sz)
121104 		rc = plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_LOANED, vpa + i, 0);
....@@ -127,11 +110,15 @@
127110 	return rc;
128111 }
129112 
130
-static long plpar_page_set_active(unsigned long vpa)
113
+static long plpar_page_set_active(struct page *page)
131114 {
115
+	const unsigned long vpa = page_to_phys(page);
132116 	unsigned long cmo_page_sz = cmo_get_page_size();
133117 	long rc = 0;
134118 	int i;
119
+
120
+	if (unlikely(simulate))
121
+		return 0;
135122 
136123 	for (i = 0; !rc && i < PAGE_SIZE; i += cmo_page_sz)
137124 		rc = plpar_hcall_norets(H_PAGE_INIT, H_PAGE_SET_ACTIVE, vpa + i, 0);
....@@ -152,8 +139,7 @@
152139  **/
153140 static long cmm_alloc_pages(long nr)
154141 {
155
-	struct cmm_page_array *pa, *npa;
156
-	unsigned long addr;
142
+	struct page *page;
157143 	long rc;
158144 
159145 	cmm_dbg("Begin request for %ld pages\n", nr);
....@@ -170,46 +156,19 @@
170156 			break;
171157 		}
172158 
173
-		addr = __get_free_page(GFP_NOIO | __GFP_NOWARN |
174
-				       __GFP_NORETRY | __GFP_NOMEMALLOC);
175
-		if (!addr)
159
+		page = balloon_page_alloc();
160
+		if (!page)
176161 			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);
182
-			npa = (struct cmm_page_array *)__get_free_page(
183
-					GFP_NOIO | __GFP_NOWARN |
184
-					__GFP_NORETRY | __GFP_NOMEMALLOC);
185
-			if (!npa) {
186
-				pr_info("%s: Can not allocate new page list\n", __func__);
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)))) {
162
+		rc = plpar_page_set_loaned(page);
163
+		if (rc) {
203164 			pr_err("%s: Can not set page to loaned. rc=%ld\n", __func__, rc);
204
-			spin_unlock(&cmm_lock);
205
-			free_page(addr);
165
+			__free_page(page);
206166 			break;
207167 		}
208168 
209
-		pa->page[pa->index++] = addr;
210
-		loaned_pages++;
211
-		totalram_pages--;
212
-		spin_unlock(&cmm_lock);
169
+		balloon_page_enqueue(&b_dev_info, page);
170
+		atomic_long_inc(&loaned_pages);
171
+		adjust_managed_page_count(page, -1);
213172 		nr--;
214173 	}
215174 
....@@ -226,30 +185,19 @@
226185  **/
227186 static long cmm_free_pages(long nr)
228187 {
229
-	struct cmm_page_array *pa;
230
-	unsigned long addr;
188
+	struct page *page;
231189 
232190 	cmm_dbg("Begin free of %ld pages.\n", nr);
233
-	spin_lock(&cmm_lock);
234
-	pa = cmm_page_list;
235191 	while (nr) {
236
-		if (!pa || pa->index <= 0)
192
+		page = balloon_page_dequeue(&b_dev_info);
193
+		if (!page)
237194 			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--;
195
+		plpar_page_set_active(page);
196
+		adjust_managed_page_count(page, 1);
197
+		__free_page(page);
198
+		atomic_long_dec(&loaned_pages);
249199 		nr--;
250
-		totalram_pages++;
251200 	}
252
-	spin_unlock(&cmm_lock);
253201 	cmm_dbg("End request with %ld pages unfulfilled\n", nr);
254202 	return nr;
255203 }
....@@ -271,7 +219,7 @@
271219 
272220 	cmm_dbg("OOM processing started\n");
273221 	nr = cmm_free_pages(nr);
274
-	loaned_pages_target = loaned_pages;
222
+	loaned_pages_target = atomic_long_read(&loaned_pages);
275223 	*freed += KB2PAGES(oom_kb) - nr;
276224 	oom_freed_pages += KB2PAGES(oom_kb) - nr;
277225 	cmm_dbg("OOM processing complete\n");
....@@ -288,19 +236,24 @@
288236  **/
289237 static void cmm_get_mpp(void)
290238 {
239
+	const long __loaned_pages = atomic_long_read(&loaned_pages);
240
+	const long total_pages = totalram_pages() + __loaned_pages;
291241 	int rc;
292242 	struct hvcall_mpp_data mpp_data;
293243 	signed long active_pages_target, page_loan_request, target;
294
-	signed long total_pages = totalram_pages + loaned_pages;
295244 	signed long min_mem_pages = (min_mem_mb * 1024 * 1024) / PAGE_SIZE;
296245 
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);
303
-	target = page_loan_request + (signed long)loaned_pages;
246
+	if (likely(!simulate)) {
247
+		rc = h_get_mpp(&mpp_data);
248
+		if (rc != H_SUCCESS)
249
+			return;
250
+		page_loan_request = div_s64((s64)mpp_data.loan_request,
251
+					    PAGE_SIZE);
252
+		target = page_loan_request + __loaned_pages;
253
+	} else {
254
+		target = KB2PAGES(simulate_loan_target_kb);
255
+		page_loan_request = target - __loaned_pages;
256
+	}
304257 
305258 	if (target < 0 || total_pages < min_mem_pages)
306259 		target = 0;
....@@ -321,8 +274,8 @@
321274 	loaned_pages_target = target;
322275 
323276 	cmm_dbg("delta = %ld, loaned = %lu, target = %lu, oom = %lu, totalram = %lu\n",
324
-		page_loan_request, loaned_pages, loaned_pages_target,
325
-		oom_freed_pages, totalram_pages);
277
+		page_loan_request, __loaned_pages, loaned_pages_target,
278
+		oom_freed_pages, totalram_pages());
326279 }
327280 
328281 static struct notifier_block cmm_oom_nb = {
....@@ -339,6 +292,7 @@
339292 static int cmm_thread(void *dummy)
340293 {
341294 	unsigned long timeleft;
295
+	long __loaned_pages;
342296 
343297 	while (1) {
344298 		timeleft = msleep_interruptible(delay * 1000);
....@@ -369,11 +323,12 @@
369323 
370324 		cmm_get_mpp();
371325 
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);
326
+		__loaned_pages = atomic_long_read(&loaned_pages);
327
+		if (loaned_pages_target > __loaned_pages) {
328
+			if (cmm_alloc_pages(loaned_pages_target - __loaned_pages))
329
+				loaned_pages_target = __loaned_pages;
330
+		} else if (loaned_pages_target < __loaned_pages)
331
+			cmm_free_pages(__loaned_pages - loaned_pages_target);
377332 	}
378333 	return 0;
379334 }
....@@ -387,7 +342,7 @@
387342 	}							\
388343 	static DEVICE_ATTR(name, 0444, show_##name, NULL)
389344 
390
-CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(loaned_pages));
345
+CMM_SHOW(loaned_kb, "%lu\n", PAGES2KB(atomic_long_read(&loaned_pages)));
391346 CMM_SHOW(loaned_target_kb, "%lu\n", PAGES2KB(loaned_pages_target));
392347 
393348 static ssize_t show_oom_pages(struct device *dev,
....@@ -419,6 +374,9 @@
419374 	&dev_attr_loaned_target_kb,
420375 	&dev_attr_oom_freed_kb,
421376 };
377
+
378
+static DEVICE_ULONG_ATTR(simulate_loan_target_kb, 0644,
379
+			 simulate_loan_target_kb);
422380 
423381 static struct bus_type cmm_subsys = {
424382 	.name = "cmm",
....@@ -454,6 +412,11 @@
454412 			goto fail;
455413 	}
456414 
415
+	if (!simulate)
416
+		return 0;
417
+	rc = device_create_file(dev, &dev_attr_simulate_loan_target_kb.attr);
418
+	if (rc)
419
+		goto fail;
457420 	return 0;
458421 
459422 fail:
....@@ -490,7 +453,7 @@
490453 		if (cmm_thread_ptr)
491454 			kthread_stop(cmm_thread_ptr);
492455 		cmm_thread_ptr = NULL;
493
-		cmm_free_pages(loaned_pages);
456
+		cmm_free_pages(atomic_long_read(&loaned_pages));
494457 	}
495458 	return NOTIFY_DONE;
496459 }
....@@ -498,142 +461,6 @@
498461 static struct notifier_block cmm_reboot_nb = {
499462 	.notifier_call = cmm_reboot_notifier,
500463 };
501
-
502
-/**
503
- * cmm_count_pages - Count the number of pages loaned in a particular range.
504
- *
505
- * @arg: memory_isolate_notify structure with address range and count
506
- *
507
- * Return value:
508
- *      0 on success
509
- **/
510
-static unsigned long cmm_count_pages(void *arg)
511
-{
512
-	struct memory_isolate_notify *marg = arg;
513
-	struct cmm_page_array *pa;
514
-	unsigned long start = (unsigned long)pfn_to_kaddr(marg->start_pfn);
515
-	unsigned long end = start + (marg->nr_pages << PAGE_SHIFT);
516
-	unsigned long idx;
517
-
518
-	spin_lock(&cmm_lock);
519
-	pa = cmm_page_list;
520
-	while (pa) {
521
-		if ((unsigned long)pa >= start && (unsigned long)pa < end)
522
-			marg->pages_found++;
523
-		for (idx = 0; idx < pa->index; idx++)
524
-			if (pa->page[idx] >= start && pa->page[idx] < end)
525
-				marg->pages_found++;
526
-		pa = pa->next;
527
-	}
528
-	spin_unlock(&cmm_lock);
529
-	return 0;
530
-}
531
-
532
-/**
533
- * cmm_memory_isolate_cb - Handle memory isolation notifier calls
534
- * @self:	notifier block struct
535
- * @action:	action to take
536
- * @arg:	struct memory_isolate_notify data for handler
537
- *
538
- * Return value:
539
- *	NOTIFY_OK or notifier error based on subfunction return value
540
- **/
541
-static int cmm_memory_isolate_cb(struct notifier_block *self,
542
-				 unsigned long action, void *arg)
543
-{
544
-	int ret = 0;
545
-
546
-	if (action == MEM_ISOLATE_COUNT)
547
-		ret = cmm_count_pages(arg);
548
-
549
-	return notifier_from_errno(ret);
550
-}
551
-
552
-static struct notifier_block cmm_mem_isolate_nb = {
553
-	.notifier_call = cmm_memory_isolate_cb,
554
-	.priority = CMM_MEM_ISOLATE_PRI
555
-};
556
-
557
-/**
558
- * cmm_mem_going_offline - Unloan pages where memory is to be removed
559
- * @arg: memory_notify structure with page range to be offlined
560
- *
561
- * Return value:
562
- *	0 on success
563
- **/
564
-static int cmm_mem_going_offline(void *arg)
565
-{
566
-	struct memory_notify *marg = arg;
567
-	unsigned long start_page = (unsigned long)pfn_to_kaddr(marg->start_pfn);
568
-	unsigned long end_page = start_page + (marg->nr_pages << PAGE_SHIFT);
569
-	struct cmm_page_array *pa_curr, *pa_last, *npa;
570
-	unsigned long idx;
571
-	unsigned long freed = 0;
572
-
573
-	cmm_dbg("Memory going offline, searching 0x%lx (%ld pages).\n",
574
-			start_page, marg->nr_pages);
575
-	spin_lock(&cmm_lock);
576
-
577
-	/* Search the page list for pages in the range to be offlined */
578
-	pa_last = pa_curr = cmm_page_list;
579
-	while (pa_curr) {
580
-		for (idx = (pa_curr->index - 1); (idx + 1) > 0; idx--) {
581
-			if ((pa_curr->page[idx] < start_page) ||
582
-			    (pa_curr->page[idx] >= end_page))
583
-				continue;
584
-
585
-			plpar_page_set_active(__pa(pa_curr->page[idx]));
586
-			free_page(pa_curr->page[idx]);
587
-			freed++;
588
-			loaned_pages--;
589
-			totalram_pages++;
590
-			pa_curr->page[idx] = pa_last->page[--pa_last->index];
591
-			if (pa_last->index == 0) {
592
-				if (pa_curr == pa_last)
593
-					pa_curr = pa_last->next;
594
-				pa_last = pa_last->next;
595
-				free_page((unsigned long)cmm_page_list);
596
-				cmm_page_list = pa_last;
597
-			}
598
-		}
599
-		pa_curr = pa_curr->next;
600
-	}
601
-
602
-	/* Search for page list structures in the range to be offlined */
603
-	pa_last = NULL;
604
-	pa_curr = cmm_page_list;
605
-	while (pa_curr) {
606
-		if (((unsigned long)pa_curr >= start_page) &&
607
-				((unsigned long)pa_curr < end_page)) {
608
-			npa = (struct cmm_page_array *)__get_free_page(
609
-					GFP_NOIO | __GFP_NOWARN |
610
-					__GFP_NORETRY | __GFP_NOMEMALLOC);
611
-			if (!npa) {
612
-				spin_unlock(&cmm_lock);
613
-				cmm_dbg("Failed to allocate memory for list "
614
-						"management. Memory hotplug "
615
-						"failed.\n");
616
-				return -ENOMEM;
617
-			}
618
-			memcpy(npa, pa_curr, PAGE_SIZE);
619
-			if (pa_curr == cmm_page_list)
620
-				cmm_page_list = npa;
621
-			if (pa_last)
622
-				pa_last->next = npa;
623
-			free_page((unsigned long) pa_curr);
624
-			freed++;
625
-			pa_curr = npa;
626
-		}
627
-
628
-		pa_last = pa_curr;
629
-		pa_curr = pa_curr->next;
630
-	}
631
-
632
-	spin_unlock(&cmm_lock);
633
-	cmm_dbg("Released %ld pages in the search range.\n", freed);
634
-
635
-	return 0;
636
-}
637464 
638465 /**
639466  * cmm_memory_cb - Handle memory hotplug notifier calls
....@@ -654,7 +481,6 @@
654481 	case MEM_GOING_OFFLINE:
655482 		mutex_lock(&hotplug_mutex);
656483 		hotplug_occurred = 1;
657
-		ret = cmm_mem_going_offline(arg);
658484 		break;
659485 	case MEM_OFFLINE:
660486 	case MEM_CANCEL_OFFLINE:
....@@ -675,6 +501,116 @@
675501 	.priority = CMM_MEM_HOTPLUG_PRI
676502 };
677503 
504
+#ifdef CONFIG_BALLOON_COMPACTION
505
+static struct vfsmount *balloon_mnt;
506
+
507
+static int cmm_init_fs_context(struct fs_context *fc)
508
+{
509
+	return init_pseudo(fc, PPC_CMM_MAGIC) ? 0 : -ENOMEM;
510
+}
511
+
512
+static struct file_system_type balloon_fs = {
513
+	.name = "ppc-cmm",
514
+	.init_fs_context = cmm_init_fs_context,
515
+	.kill_sb = kill_anon_super,
516
+};
517
+
518
+static int cmm_migratepage(struct balloon_dev_info *b_dev_info,
519
+			   struct page *newpage, struct page *page,
520
+			   enum migrate_mode mode)
521
+{
522
+	unsigned long flags;
523
+
524
+	/*
525
+	 * loan/"inflate" the newpage first.
526
+	 *
527
+	 * We might race against the cmm_thread who might discover after our
528
+	 * loan request that another page is to be unloaned. However, once
529
+	 * the cmm_thread runs again later, this error will automatically
530
+	 * be corrected.
531
+	 */
532
+	if (plpar_page_set_loaned(newpage)) {
533
+		/* Unlikely, but possible. Tell the caller not to retry now. */
534
+		pr_err_ratelimited("%s: Cannot set page to loaned.", __func__);
535
+		return -EBUSY;
536
+	}
537
+
538
+	/* balloon page list reference */
539
+	get_page(newpage);
540
+
541
+	/*
542
+	 * When we migrate a page to a different zone, we have to fixup the
543
+	 * count of both involved zones as we adjusted the managed page count
544
+	 * when inflating.
545
+	 */
546
+	if (page_zone(page) != page_zone(newpage)) {
547
+		adjust_managed_page_count(page, 1);
548
+		adjust_managed_page_count(newpage, -1);
549
+	}
550
+
551
+	spin_lock_irqsave(&b_dev_info->pages_lock, flags);
552
+	balloon_page_insert(b_dev_info, newpage);
553
+	balloon_page_delete(page);
554
+	b_dev_info->isolated_pages--;
555
+	spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
556
+
557
+	/*
558
+	 * activate/"deflate" the old page. We ignore any errors just like the
559
+	 * other callers.
560
+	 */
561
+	plpar_page_set_active(page);
562
+
563
+	/* balloon page list reference */
564
+	put_page(page);
565
+
566
+	return MIGRATEPAGE_SUCCESS;
567
+}
568
+
569
+static int cmm_balloon_compaction_init(void)
570
+{
571
+	int rc;
572
+
573
+	balloon_devinfo_init(&b_dev_info);
574
+	b_dev_info.migratepage = cmm_migratepage;
575
+
576
+	balloon_mnt = kern_mount(&balloon_fs);
577
+	if (IS_ERR(balloon_mnt)) {
578
+		rc = PTR_ERR(balloon_mnt);
579
+		balloon_mnt = NULL;
580
+		return rc;
581
+	}
582
+
583
+	b_dev_info.inode = alloc_anon_inode(balloon_mnt->mnt_sb);
584
+	if (IS_ERR(b_dev_info.inode)) {
585
+		rc = PTR_ERR(b_dev_info.inode);
586
+		b_dev_info.inode = NULL;
587
+		kern_unmount(balloon_mnt);
588
+		balloon_mnt = NULL;
589
+		return rc;
590
+	}
591
+
592
+	b_dev_info.inode->i_mapping->a_ops = &balloon_aops;
593
+	return 0;
594
+}
595
+static void cmm_balloon_compaction_deinit(void)
596
+{
597
+	if (b_dev_info.inode)
598
+		iput(b_dev_info.inode);
599
+	b_dev_info.inode = NULL;
600
+	kern_unmount(balloon_mnt);
601
+	balloon_mnt = NULL;
602
+}
603
+#else /* CONFIG_BALLOON_COMPACTION */
604
+static int cmm_balloon_compaction_init(void)
605
+{
606
+	return 0;
607
+}
608
+
609
+static void cmm_balloon_compaction_deinit(void)
610
+{
611
+}
612
+#endif /* CONFIG_BALLOON_COMPACTION */
613
+
678614 /**
679615  * cmm_init - Module initialization
680616  *
....@@ -683,13 +619,18 @@
683619  **/
684620 static int cmm_init(void)
685621 {
686
-	int rc = -ENOMEM;
622
+	int rc;
687623 
688
-	if (!firmware_has_feature(FW_FEATURE_CMO))
624
+	if (!firmware_has_feature(FW_FEATURE_CMO) && !simulate)
689625 		return -EOPNOTSUPP;
690626 
691
-	if ((rc = register_oom_notifier(&cmm_oom_nb)) < 0)
627
+	rc = cmm_balloon_compaction_init();
628
+	if (rc)
692629 		return rc;
630
+
631
+	rc = register_oom_notifier(&cmm_oom_nb);
632
+	if (rc < 0)
633
+		goto out_balloon_compaction;
693634 
694635 	if ((rc = register_reboot_notifier(&cmm_reboot_nb)))
695636 		goto out_oom_notifier;
....@@ -697,12 +638,12 @@
697638 	if ((rc = cmm_sysfs_register(&cmm_dev)))
698639 		goto out_reboot_notifier;
699640 
700
-	if (register_memory_notifier(&cmm_mem_nb) ||
701
-	    register_memory_isolate_notifier(&cmm_mem_isolate_nb))
641
+	rc = register_memory_notifier(&cmm_mem_nb);
642
+	if (rc)
702643 		goto out_unregister_notifier;
703644 
704645 	if (cmm_disabled)
705
-		return rc;
646
+		return 0;
706647 
707648 	cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
708649 	if (IS_ERR(cmm_thread_ptr)) {
....@@ -710,16 +651,16 @@
710651 		goto out_unregister_notifier;
711652 	}
712653 
713
-	return rc;
714
-
654
+	return 0;
715655 out_unregister_notifier:
716656 	unregister_memory_notifier(&cmm_mem_nb);
717
-	unregister_memory_isolate_notifier(&cmm_mem_isolate_nb);
718657 	cmm_unregister_sysfs(&cmm_dev);
719658 out_reboot_notifier:
720659 	unregister_reboot_notifier(&cmm_reboot_nb);
721660 out_oom_notifier:
722661 	unregister_oom_notifier(&cmm_oom_nb);
662
+out_balloon_compaction:
663
+	cmm_balloon_compaction_deinit();
723664 	return rc;
724665 }
725666 
....@@ -736,9 +677,9 @@
736677 	unregister_oom_notifier(&cmm_oom_nb);
737678 	unregister_reboot_notifier(&cmm_reboot_nb);
738679 	unregister_memory_notifier(&cmm_mem_nb);
739
-	unregister_memory_isolate_notifier(&cmm_mem_isolate_nb);
740
-	cmm_free_pages(loaned_pages);
680
+	cmm_free_pages(atomic_long_read(&loaned_pages));
741681 	cmm_unregister_sysfs(&cmm_dev);
682
+	cmm_balloon_compaction_deinit();
742683 }
743684 
744685 /**
....@@ -758,7 +699,7 @@
758699 		if (cmm_thread_ptr)
759700 			kthread_stop(cmm_thread_ptr);
760701 		cmm_thread_ptr = NULL;
761
-		cmm_free_pages(loaned_pages);
702
+		cmm_free_pages(atomic_long_read(&loaned_pages));
762703 	} else if (!disable && cmm_disabled) {
763704 		cmm_thread_ptr = kthread_run(cmm_thread, NULL, "cmmthread");
764705 		if (IS_ERR(cmm_thread_ptr))