Commit | Line | Data |
---|---|---|
155af2f9 | 1 | /* |
c48ff644 | 2 | * Suspend support specific for s390. |
155af2f9 HJP |
3 | * |
4 | * Copyright IBM Corp. 2009 | |
5 | * | |
6 | * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com> | |
155af2f9 HJP |
7 | */ |
8 | ||
c48ff644 | 9 | #include <linux/pfn.h> |
638ad34a | 10 | #include <linux/suspend.h> |
85055dd8 | 11 | #include <linux/mm.h> |
c63b196a | 12 | #include <asm/system.h> |
c48ff644 HC |
13 | |
14 | /* | |
15 | * References to section boundaries | |
16 | */ | |
17 | extern const void __nosave_begin, __nosave_end; | |
18 | ||
85055dd8 MS |
19 | /* |
20 | * The restore of the saved pages in an hibernation image will set | |
21 | * the change and referenced bits in the storage key for each page. | |
22 | * Overindication of the referenced bits after an hibernation cycle | |
23 | * does not cause any harm but the overindication of the change bits | |
24 | * would cause trouble. | |
25 | * Use the ARCH_SAVE_PAGE_KEYS hooks to save the storage key of each | |
26 | * page to the most significant byte of the associated page frame | |
27 | * number in the hibernation image. | |
28 | */ | |
29 | ||
30 | /* | |
31 | * Key storage is allocated as a linked list of pages. | |
32 | * The size of the keys array is (PAGE_SIZE - sizeof(long)) | |
33 | */ | |
34 | struct page_key_data { | |
35 | struct page_key_data *next; | |
36 | unsigned char data[]; | |
37 | }; | |
38 | ||
39 | #define PAGE_KEY_DATA_SIZE (PAGE_SIZE - sizeof(struct page_key_data *)) | |
40 | ||
41 | static struct page_key_data *page_key_data; | |
42 | static struct page_key_data *page_key_rp, *page_key_wp; | |
43 | static unsigned long page_key_rx, page_key_wx; | |
44 | ||
45 | /* | |
46 | * For each page in the hibernation image one additional byte is | |
47 | * stored in the most significant byte of the page frame number. | |
48 | * On suspend no additional memory is required but on resume the | |
49 | * keys need to be memorized until the page data has been restored. | |
50 | * Only then can the storage keys be set to their old state. | |
51 | */ | |
52 | unsigned long page_key_additional_pages(unsigned long pages) | |
53 | { | |
54 | return DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE); | |
55 | } | |
56 | ||
57 | /* | |
58 | * Free page_key_data list of arrays. | |
59 | */ | |
60 | void page_key_free(void) | |
61 | { | |
62 | struct page_key_data *pkd; | |
63 | ||
64 | while (page_key_data) { | |
65 | pkd = page_key_data; | |
66 | page_key_data = pkd->next; | |
67 | free_page((unsigned long) pkd); | |
68 | } | |
69 | } | |
70 | ||
71 | /* | |
72 | * Allocate page_key_data list of arrays with enough room to store | |
73 | * one byte for each page in the hibernation image. | |
74 | */ | |
75 | int page_key_alloc(unsigned long pages) | |
76 | { | |
77 | struct page_key_data *pk; | |
78 | unsigned long size; | |
79 | ||
80 | size = DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE); | |
81 | while (size--) { | |
82 | pk = (struct page_key_data *) get_zeroed_page(GFP_KERNEL); | |
83 | if (!pk) { | |
84 | page_key_free(); | |
85 | return -ENOMEM; | |
86 | } | |
87 | pk->next = page_key_data; | |
88 | page_key_data = pk; | |
89 | } | |
90 | page_key_rp = page_key_wp = page_key_data; | |
91 | page_key_rx = page_key_wx = 0; | |
92 | return 0; | |
93 | } | |
94 | ||
95 | /* | |
96 | * Save the storage key into the upper 8 bits of the page frame number. | |
97 | */ | |
98 | void page_key_read(unsigned long *pfn) | |
99 | { | |
100 | unsigned long addr; | |
101 | ||
102 | addr = (unsigned long) page_address(pfn_to_page(*pfn)); | |
103 | *(unsigned char *) pfn = (unsigned char) page_get_storage_key(addr); | |
104 | } | |
105 | ||
106 | /* | |
107 | * Extract the storage key from the upper 8 bits of the page frame number | |
108 | * and store it in the page_key_data list of arrays. | |
109 | */ | |
110 | void page_key_memorize(unsigned long *pfn) | |
111 | { | |
112 | page_key_wp->data[page_key_wx] = *(unsigned char *) pfn; | |
113 | *(unsigned char *) pfn = 0; | |
114 | if (++page_key_wx < PAGE_KEY_DATA_SIZE) | |
115 | return; | |
116 | page_key_wp = page_key_wp->next; | |
117 | page_key_wx = 0; | |
118 | } | |
119 | ||
120 | /* | |
121 | * Get the next key from the page_key_data list of arrays and set the | |
122 | * storage key of the page referred by @address. If @address refers to | |
123 | * a "safe" page the swsusp_arch_resume code will transfer the storage | |
124 | * key from the buffer page to the original page. | |
125 | */ | |
126 | void page_key_write(void *address) | |
127 | { | |
128 | page_set_storage_key((unsigned long) address, | |
129 | page_key_rp->data[page_key_rx], 0); | |
130 | if (++page_key_rx >= PAGE_KEY_DATA_SIZE) | |
131 | return; | |
132 | page_key_rp = page_key_rp->next; | |
133 | page_key_rx = 0; | |
134 | } | |
135 | ||
c48ff644 HC |
136 | int pfn_is_nosave(unsigned long pfn) |
137 | { | |
2573a575 HC |
138 | unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin)); |
139 | unsigned long nosave_end_pfn = PFN_DOWN(__pa(&__nosave_end)); | |
c48ff644 | 140 | |
2573a575 HC |
141 | /* Always save lowcore pages (LC protection might be enabled). */ |
142 | if (pfn <= LC_PAGES) | |
143 | return 0; | |
c48ff644 HC |
144 | if (pfn >= nosave_begin_pfn && pfn < nosave_end_pfn) |
145 | return 1; | |
2573a575 HC |
146 | /* Skip memory holes and read-only pages (NSS, DCSS, ...). */ |
147 | if (tprot(PFN_PHYS(pfn))) | |
c48ff644 HC |
148 | return 1; |
149 | return 0; | |
150 | } | |
155af2f9 | 151 | |
155af2f9 HJP |
152 | void save_processor_state(void) |
153 | { | |
c63b196a HC |
154 | /* swsusp_arch_suspend() actually saves all cpu register contents. |
155 | * Machine checks must be disabled since swsusp_arch_suspend() stores | |
156 | * register contents to their lowcore save areas. That's the same | |
157 | * place where register contents on machine checks would be saved. | |
158 | * To avoid register corruption disable machine checks. | |
159 | * We must also disable machine checks in the new psw mask for | |
160 | * program checks, since swsusp_arch_suspend() may generate program | |
161 | * checks. Disabling machine checks for all other new psw masks is | |
162 | * just paranoia. | |
155af2f9 | 163 | */ |
c63b196a HC |
164 | local_mcck_disable(); |
165 | /* Disable lowcore protection */ | |
166 | __ctl_clear_bit(0,28); | |
167 | S390_lowcore.external_new_psw.mask &= ~PSW_MASK_MCHECK; | |
168 | S390_lowcore.svc_new_psw.mask &= ~PSW_MASK_MCHECK; | |
169 | S390_lowcore.io_new_psw.mask &= ~PSW_MASK_MCHECK; | |
170 | S390_lowcore.program_new_psw.mask &= ~PSW_MASK_MCHECK; | |
155af2f9 HJP |
171 | } |
172 | ||
155af2f9 HJP |
173 | void restore_processor_state(void) |
174 | { | |
c63b196a HC |
175 | S390_lowcore.external_new_psw.mask |= PSW_MASK_MCHECK; |
176 | S390_lowcore.svc_new_psw.mask |= PSW_MASK_MCHECK; | |
177 | S390_lowcore.io_new_psw.mask |= PSW_MASK_MCHECK; | |
178 | S390_lowcore.program_new_psw.mask |= PSW_MASK_MCHECK; | |
179 | /* Enable lowcore protection */ | |
180 | __ctl_set_bit(0,28); | |
181 | local_mcck_enable(); | |
155af2f9 | 182 | } |