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