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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
155af2f9 | 2 | /* |
c48ff644 | 3 | * Suspend support specific for s390. |
155af2f9 HJP |
4 | * |
5 | * Copyright IBM Corp. 2009 | |
6 | * | |
7 | * Author(s): Hans-Joachim Picht <hans@linux.vnet.ibm.com> | |
155af2f9 HJP |
8 | */ |
9 | ||
c48ff644 | 10 | #include <linux/pfn.h> |
638ad34a | 11 | #include <linux/suspend.h> |
85055dd8 | 12 | #include <linux/mm.h> |
cd11433e | 13 | #include <linux/pci.h> |
a0616cde | 14 | #include <asm/ctl_reg.h> |
77e844b9 SO |
15 | #include <asm/ipl.h> |
16 | #include <asm/cio.h> | |
7f8998c7 | 17 | #include <asm/sections.h> |
63df41d6 | 18 | #include "entry.h" |
c48ff644 | 19 | |
85055dd8 MS |
20 | /* |
21 | * The restore of the saved pages in an hibernation image will set | |
22 | * the change and referenced bits in the storage key for each page. | |
23 | * Overindication of the referenced bits after an hibernation cycle | |
24 | * does not cause any harm but the overindication of the change bits | |
25 | * would cause trouble. | |
26 | * Use the ARCH_SAVE_PAGE_KEYS hooks to save the storage key of each | |
27 | * page to the most significant byte of the associated page frame | |
28 | * number in the hibernation image. | |
29 | */ | |
30 | ||
31 | /* | |
32 | * Key storage is allocated as a linked list of pages. | |
33 | * The size of the keys array is (PAGE_SIZE - sizeof(long)) | |
34 | */ | |
35 | struct page_key_data { | |
36 | struct page_key_data *next; | |
37 | unsigned char data[]; | |
38 | }; | |
39 | ||
40 | #define PAGE_KEY_DATA_SIZE (PAGE_SIZE - sizeof(struct page_key_data *)) | |
41 | ||
42 | static struct page_key_data *page_key_data; | |
43 | static struct page_key_data *page_key_rp, *page_key_wp; | |
44 | static unsigned long page_key_rx, page_key_wx; | |
91c15a95 | 45 | unsigned long suspend_zero_pages; |
85055dd8 MS |
46 | |
47 | /* | |
48 | * For each page in the hibernation image one additional byte is | |
49 | * stored in the most significant byte of the page frame number. | |
50 | * On suspend no additional memory is required but on resume the | |
51 | * keys need to be memorized until the page data has been restored. | |
52 | * Only then can the storage keys be set to their old state. | |
53 | */ | |
54 | unsigned long page_key_additional_pages(unsigned long pages) | |
55 | { | |
56 | return DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE); | |
57 | } | |
58 | ||
59 | /* | |
60 | * Free page_key_data list of arrays. | |
61 | */ | |
62 | void page_key_free(void) | |
63 | { | |
64 | struct page_key_data *pkd; | |
65 | ||
66 | while (page_key_data) { | |
67 | pkd = page_key_data; | |
68 | page_key_data = pkd->next; | |
69 | free_page((unsigned long) pkd); | |
70 | } | |
71 | } | |
72 | ||
73 | /* | |
74 | * Allocate page_key_data list of arrays with enough room to store | |
75 | * one byte for each page in the hibernation image. | |
76 | */ | |
77 | int page_key_alloc(unsigned long pages) | |
78 | { | |
79 | struct page_key_data *pk; | |
80 | unsigned long size; | |
81 | ||
82 | size = DIV_ROUND_UP(pages, PAGE_KEY_DATA_SIZE); | |
83 | while (size--) { | |
84 | pk = (struct page_key_data *) get_zeroed_page(GFP_KERNEL); | |
85 | if (!pk) { | |
86 | page_key_free(); | |
87 | return -ENOMEM; | |
88 | } | |
89 | pk->next = page_key_data; | |
90 | page_key_data = pk; | |
91 | } | |
92 | page_key_rp = page_key_wp = page_key_data; | |
93 | page_key_rx = page_key_wx = 0; | |
94 | return 0; | |
95 | } | |
96 | ||
97 | /* | |
98 | * Save the storage key into the upper 8 bits of the page frame number. | |
99 | */ | |
100 | void page_key_read(unsigned long *pfn) | |
101 | { | |
c9b5ad54 | 102 | struct page *page; |
85055dd8 | 103 | unsigned long addr; |
c9b5ad54 MS |
104 | unsigned char key; |
105 | ||
106 | page = pfn_to_page(*pfn); | |
107 | addr = (unsigned long) page_address(page); | |
108 | key = (unsigned char) page_get_storage_key(addr) & 0x7f; | |
109 | if (arch_test_page_nodat(page)) | |
110 | key |= 0x80; | |
111 | *(unsigned char *) pfn = key; | |
85055dd8 MS |
112 | } |
113 | ||
114 | /* | |
115 | * Extract the storage key from the upper 8 bits of the page frame number | |
116 | * and store it in the page_key_data list of arrays. | |
117 | */ | |
118 | void page_key_memorize(unsigned long *pfn) | |
119 | { | |
120 | page_key_wp->data[page_key_wx] = *(unsigned char *) pfn; | |
121 | *(unsigned char *) pfn = 0; | |
122 | if (++page_key_wx < PAGE_KEY_DATA_SIZE) | |
123 | return; | |
124 | page_key_wp = page_key_wp->next; | |
125 | page_key_wx = 0; | |
126 | } | |
127 | ||
128 | /* | |
129 | * Get the next key from the page_key_data list of arrays and set the | |
130 | * storage key of the page referred by @address. If @address refers to | |
131 | * a "safe" page the swsusp_arch_resume code will transfer the storage | |
132 | * key from the buffer page to the original page. | |
133 | */ | |
134 | void page_key_write(void *address) | |
135 | { | |
c9b5ad54 MS |
136 | struct page *page; |
137 | unsigned char key; | |
138 | ||
139 | key = page_key_rp->data[page_key_rx]; | |
140 | page_set_storage_key((unsigned long) address, key & 0x7f, 0); | |
141 | page = virt_to_page(address); | |
142 | if (key & 0x80) | |
143 | arch_set_page_nodat(page, 0); | |
144 | else | |
145 | arch_set_page_dat(page, 0); | |
85055dd8 MS |
146 | if (++page_key_rx >= PAGE_KEY_DATA_SIZE) |
147 | return; | |
148 | page_key_rp = page_key_rp->next; | |
149 | page_key_rx = 0; | |
150 | } | |
151 | ||
c48ff644 HC |
152 | int pfn_is_nosave(unsigned long pfn) |
153 | { | |
2573a575 HC |
154 | unsigned long nosave_begin_pfn = PFN_DOWN(__pa(&__nosave_begin)); |
155 | unsigned long nosave_end_pfn = PFN_DOWN(__pa(&__nosave_end)); | |
d7441949 HC |
156 | unsigned long eshared_pfn = PFN_DOWN(__pa(&_eshared)) - 1; |
157 | unsigned long stext_pfn = PFN_DOWN(__pa(&_stext)); | |
c48ff644 | 158 | |
2573a575 HC |
159 | /* Always save lowcore pages (LC protection might be enabled). */ |
160 | if (pfn <= LC_PAGES) | |
161 | return 0; | |
c48ff644 HC |
162 | if (pfn >= nosave_begin_pfn && pfn < nosave_end_pfn) |
163 | return 1; | |
2573a575 | 164 | /* Skip memory holes and read-only pages (NSS, DCSS, ...). */ |
d7441949 HC |
165 | if (pfn >= stext_pfn && pfn <= eshared_pfn) |
166 | return ipl_info.type == IPL_TYPE_NSS ? 1 : 0; | |
2573a575 | 167 | if (tprot(PFN_PHYS(pfn))) |
c48ff644 HC |
168 | return 1; |
169 | return 0; | |
170 | } | |
155af2f9 | 171 | |
91c15a95 MH |
172 | /* |
173 | * PM notifier callback for suspend | |
174 | */ | |
175 | static int suspend_pm_cb(struct notifier_block *nb, unsigned long action, | |
176 | void *ptr) | |
177 | { | |
178 | switch (action) { | |
179 | case PM_SUSPEND_PREPARE: | |
180 | case PM_HIBERNATION_PREPARE: | |
181 | suspend_zero_pages = __get_free_pages(GFP_KERNEL, LC_ORDER); | |
182 | if (!suspend_zero_pages) | |
183 | return NOTIFY_BAD; | |
184 | break; | |
185 | case PM_POST_SUSPEND: | |
186 | case PM_POST_HIBERNATION: | |
187 | free_pages(suspend_zero_pages, LC_ORDER); | |
188 | break; | |
189 | default: | |
190 | return NOTIFY_DONE; | |
191 | } | |
192 | return NOTIFY_OK; | |
193 | } | |
194 | ||
195 | static int __init suspend_pm_init(void) | |
196 | { | |
197 | pm_notifier(suspend_pm_cb, 0); | |
198 | return 0; | |
199 | } | |
200 | arch_initcall(suspend_pm_init); | |
201 | ||
155af2f9 HJP |
202 | void save_processor_state(void) |
203 | { | |
c63b196a HC |
204 | /* swsusp_arch_suspend() actually saves all cpu register contents. |
205 | * Machine checks must be disabled since swsusp_arch_suspend() stores | |
206 | * register contents to their lowcore save areas. That's the same | |
207 | * place where register contents on machine checks would be saved. | |
208 | * To avoid register corruption disable machine checks. | |
209 | * We must also disable machine checks in the new psw mask for | |
210 | * program checks, since swsusp_arch_suspend() may generate program | |
211 | * checks. Disabling machine checks for all other new psw masks is | |
212 | * just paranoia. | |
155af2f9 | 213 | */ |
c63b196a HC |
214 | local_mcck_disable(); |
215 | /* Disable lowcore protection */ | |
216 | __ctl_clear_bit(0,28); | |
217 | S390_lowcore.external_new_psw.mask &= ~PSW_MASK_MCHECK; | |
218 | S390_lowcore.svc_new_psw.mask &= ~PSW_MASK_MCHECK; | |
219 | S390_lowcore.io_new_psw.mask &= ~PSW_MASK_MCHECK; | |
220 | S390_lowcore.program_new_psw.mask &= ~PSW_MASK_MCHECK; | |
155af2f9 HJP |
221 | } |
222 | ||
155af2f9 HJP |
223 | void restore_processor_state(void) |
224 | { | |
c63b196a HC |
225 | S390_lowcore.external_new_psw.mask |= PSW_MASK_MCHECK; |
226 | S390_lowcore.svc_new_psw.mask |= PSW_MASK_MCHECK; | |
227 | S390_lowcore.io_new_psw.mask |= PSW_MASK_MCHECK; | |
228 | S390_lowcore.program_new_psw.mask |= PSW_MASK_MCHECK; | |
229 | /* Enable lowcore protection */ | |
230 | __ctl_set_bit(0,28); | |
231 | local_mcck_enable(); | |
155af2f9 | 232 | } |
77e844b9 SO |
233 | |
234 | /* Called at the end of swsusp_arch_resume */ | |
235 | void s390_early_resume(void) | |
236 | { | |
237 | lgr_info_log(); | |
238 | channel_subsystem_reinit(); | |
57b5918c | 239 | zpci_rescan(); |
77e844b9 | 240 | } |