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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2011-08-17 14:42:24 -0400
committerRafael J. Wysocki <rjw@sisk.pl>2011-10-16 17:27:46 -0400
commit85055dd805f0822f13f736bee2a521e222c38293 (patch)
treeedbad90395fc7471732edfb5372adcd7e55e791b /arch
parentca123102f69fb260221502ade9bbc069290fae84 (diff)
PM / Hibernate: Include storage keys in hibernation image on s390
For s390 there is one additional byte associated with each page, the storage key. This byte contains the referenced and changed bits and needs to be included into the hibernation image. If the storage keys are not restored to their previous state all original pages would appear to be dirty. This can cause inconsistencies e.g. with read-only filesystems. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/Kconfig1
-rw-r--r--arch/s390/kernel/suspend.c118
-rw-r--r--arch/s390/kernel/swsusp_asm64.S3
3 files changed, 122 insertions, 0 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index ed5cb5af5281..6b99fc3f9b63 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -91,6 +91,7 @@ config S390
91 select HAVE_ARCH_MUTEX_CPU_RELAX 91 select HAVE_ARCH_MUTEX_CPU_RELAX
92 select HAVE_ARCH_JUMP_LABEL if !MARCH_G5 92 select HAVE_ARCH_JUMP_LABEL if !MARCH_G5
93 select HAVE_RCU_TABLE_FREE if SMP 93 select HAVE_RCU_TABLE_FREE if SMP
94 select ARCH_SAVE_PAGE_KEYS if HIBERNATION
94 select ARCH_INLINE_SPIN_TRYLOCK 95 select ARCH_INLINE_SPIN_TRYLOCK
95 select ARCH_INLINE_SPIN_TRYLOCK_BH 96 select ARCH_INLINE_SPIN_TRYLOCK_BH
96 select ARCH_INLINE_SPIN_LOCK 97 select ARCH_INLINE_SPIN_LOCK
diff --git a/arch/s390/kernel/suspend.c b/arch/s390/kernel/suspend.c
index cf9e5c6d5527..b6f9afed74ec 100644
--- a/arch/s390/kernel/suspend.c
+++ b/arch/s390/kernel/suspend.c
@@ -7,6 +7,7 @@
7 */ 7 */
8 8
9#include <linux/pfn.h> 9#include <linux/pfn.h>
10#include <linux/mm.h>
10#include <asm/system.h> 11#include <asm/system.h>
11 12
12/* 13/*
@@ -14,6 +15,123 @@
14 */ 15 */
15extern const void __nosave_begin, __nosave_end; 16extern const void __nosave_begin, __nosave_end;
16 17
18/*
19 * The restore of the saved pages in an hibernation image will set
20 * the change and referenced bits in the storage key for each page.
21 * Overindication of the referenced bits after an hibernation cycle
22 * does not cause any harm but the overindication of the change bits
23 * would cause trouble.
24 * Use the ARCH_SAVE_PAGE_KEYS hooks to save the storage key of each
25 * page to the most significant byte of the associated page frame
26 * number in the hibernation image.
27 */
28
29/*
30 * Key storage is allocated as a linked list of pages.
31 * The size of the keys array is (PAGE_SIZE - sizeof(long))
32 */
33struct page_key_data {
34 struct page_key_data *next;
35 unsigned char data[];
36};
37
38#define PAGE_KEY_DATA_SIZE (PAGE_SIZE - sizeof(struct page_key_data *))
39
40static struct page_key_data *page_key_data;
41static struct page_key_data *page_key_rp, *page_key_wp;
42static unsigned long page_key_rx, page_key_wx;
43
44/*
45 * For each page in the hibernation image one additional byte is
46 * stored in the most significant byte of the page frame number.
47 * On suspend no additional memory is required but on resume the
48 * keys need to be memorized until the page data has been restored.
49 * Only then can the storage keys be set to their old state.
50 */
51unsigned long page_key_additional_pages(unsigned long pages)
52{
53 return DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
54}
55
56/*
57 * Free page_key_data list of arrays.
58 */
59void page_key_free(void)
60{
61 struct page_key_data *pkd;
62
63 while (page_key_data) {
64 pkd = page_key_data;
65 page_key_data = pkd->next;
66 free_page((unsigned long) pkd);
67 }
68}
69
70/*
71 * Allocate page_key_data list of arrays with enough room to store
72 * one byte for each page in the hibernation image.
73 */
74int page_key_alloc(unsigned long pages)
75{
76 struct page_key_data *pk;
77 unsigned long size;
78
79 size = DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE);
80 while (size--) {
81 pk = (struct page_key_data *) get_zeroed_page(GFP_KERNEL);
82 if (!pk) {
83 page_key_free();
84 return -ENOMEM;
85 }
86 pk->next = page_key_data;
87 page_key_data = pk;
88 }
89 page_key_rp = page_key_wp = page_key_data;
90 page_key_rx = page_key_wx = 0;
91 return 0;
92}
93
94/*
95 * Save the storage key into the upper 8 bits of the page frame number.
96 */
97void page_key_read(unsigned long *pfn)
98{
99 unsigned long addr;
100
101 addr = (unsigned long) page_address(pfn_to_page(*pfn));
102 *(unsigned char *) pfn = (unsigned char) page_get_storage_key(addr);
103}
104
105/*
106 * Extract the storage key from the upper 8 bits of the page frame number
107 * and store it in the page_key_data list of arrays.
108 */
109void page_key_memorize(unsigned long *pfn)
110{
111 page_key_wp->data[page_key_wx] = *(unsigned char *) pfn;
112 *(unsigned char *) pfn = 0;
113 if (++page_key_wx < PAGE_KEY_DATA_SIZE)
114 return;
115 page_key_wp = page_key_wp->next;
116 page_key_wx = 0;
117}
118
119/*
120 * Get the next key from the page_key_data list of arrays and set the
121 * storage key of the page referred by @address. If @address refers to
122 * a "safe" page the swsusp_arch_resume code will transfer the storage
123 * key from the buffer page to the original page.
124 */
125void page_key_write(void *address)
126{
127 page_set_storage_key((unsigned long) address,
128 page_key_rp->data[page_key_rx], 0);
129 if (++page_key_rx >= PAGE_KEY_DATA_SIZE)
130 return;
131 page_key_rp = page_key_rp->next;
132 page_key_rx = 0;
133}
134
17int pfn_is_nosave(unsigned long pfn) 135int pfn_is_nosave(unsigned long pfn)
18{ 136{
19 unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin)); 137 unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin));
diff --git a/arch/s390/kernel/swsusp_asm64.S b/arch/s390/kernel/swsusp_asm64.S
index 51bcdb50a230..acb78cdee896 100644
--- a/arch/s390/kernel/swsusp_asm64.S
+++ b/arch/s390/kernel/swsusp_asm64.S
@@ -136,11 +136,14 @@ ENTRY(swsusp_arch_resume)
1360: 1360:
137 lg %r2,8(%r1) 137 lg %r2,8(%r1)
138 lg %r4,0(%r1) 138 lg %r4,0(%r1)
139 iske %r0,%r4
139 lghi %r3,PAGE_SIZE 140 lghi %r3,PAGE_SIZE
140 lghi %r5,PAGE_SIZE 141 lghi %r5,PAGE_SIZE
1411: 1421:
142 mvcle %r2,%r4,0 143 mvcle %r2,%r4,0
143 jo 1b 144 jo 1b
145 lg %r2,8(%r1)
146 sske %r0,%r2
144 lg %r1,16(%r1) 147 lg %r1,16(%r1)
145 ltgr %r1,%r1 148 ltgr %r1,%r1
146 jnz 0b 149 jnz 0b