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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * nvs.c - Routines for saving and restoring ACPI NVS memory region
4 *
5 * Copyright (C) 2008-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
6 */
7
8#include <linux/io.h>
9#include <linux/kernel.h>
10#include <linux/list.h>
11#include <linux/mm.h>
12#include <linux/slab.h>
13#include <linux/acpi.h>
14
15#include "internal.h"
16
17/* ACPI NVS regions, APEI may use it */
18
19struct nvs_region {
20 __u64 phys_start;
21 __u64 size;
22 struct list_head node;
23};
24
25static LIST_HEAD(nvs_region_list);
26
27#ifdef CONFIG_ACPI_SLEEP
28static int suspend_nvs_register(unsigned long start, unsigned long size);
29#else
30static inline int suspend_nvs_register(unsigned long a, unsigned long b)
31{
32 return 0;
33}
34#endif
35
36int acpi_nvs_register(__u64 start, __u64 size)
37{
38 struct nvs_region *region;
39
40 region = kmalloc(sizeof(*region), GFP_KERNEL);
41 if (!region)
42 return -ENOMEM;
43 region->phys_start = start;
44 region->size = size;
45 list_add_tail(®ion->node, &nvs_region_list);
46
47 return suspend_nvs_register(start, size);
48}
49
50int acpi_nvs_for_each_region(int (*func)(__u64 start, __u64 size, void *data),
51 void *data)
52{
53 int rc;
54 struct nvs_region *region;
55
56 list_for_each_entry(region, &nvs_region_list, node) {
57 rc = func(region->phys_start, region->size, data);
58 if (rc)
59 return rc;
60 }
61
62 return 0;
63}
64
65
66#ifdef CONFIG_ACPI_SLEEP
67/*
68 * Platforms, like ACPI, may want us to save some memory used by them during
69 * suspend and to restore the contents of this memory during the subsequent
70 * resume. The code below implements a mechanism allowing us to do that.
71 */
72
73struct nvs_page {
74 unsigned long phys_start;
75 unsigned int size;
76 void *kaddr;
77 void *data;
78 bool unmap;
79 struct list_head node;
80};
81
82static LIST_HEAD(nvs_list);
83
84/**
85 * suspend_nvs_register - register platform NVS memory region to save
86 * @start - physical address of the region
87 * @size - size of the region
88 *
89 * The NVS region need not be page-aligned (both ends) and we arrange
90 * things so that the data from page-aligned addresses in this region will
91 * be copied into separate RAM pages.
92 */
93static int suspend_nvs_register(unsigned long start, unsigned long size)
94{
95 struct nvs_page *entry, *next;
96
97 pr_info("PM: Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n",
98 start, start + size - 1, size);
99
100 while (size > 0) {
101 unsigned int nr_bytes;
102
103 entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL);
104 if (!entry)
105 goto Error;
106
107 list_add_tail(&entry->node, &nvs_list);
108 entry->phys_start = start;
109 nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK);
110 entry->size = (size < nr_bytes) ? size : nr_bytes;
111
112 start += entry->size;
113 size -= entry->size;
114 }
115 return 0;
116
117 Error:
118 list_for_each_entry_safe(entry, next, &nvs_list, node) {
119 list_del(&entry->node);
120 kfree(entry);
121 }
122 return -ENOMEM;
123}
124
125/**
126 * suspend_nvs_free - free data pages allocated for saving NVS regions
127 */
128void suspend_nvs_free(void)
129{
130 struct nvs_page *entry;
131
132 list_for_each_entry(entry, &nvs_list, node)
133 if (entry->data) {
134 free_page((unsigned long)entry->data);
135 entry->data = NULL;
136 if (entry->kaddr) {
137 if (entry->unmap) {
138 iounmap(entry->kaddr);
139 entry->unmap = false;
140 } else {
141 acpi_os_unmap_iomem(entry->kaddr,
142 entry->size);
143 }
144 entry->kaddr = NULL;
145 }
146 }
147}
148
149/**
150 * suspend_nvs_alloc - allocate memory necessary for saving NVS regions
151 */
152int suspend_nvs_alloc(void)
153{
154 struct nvs_page *entry;
155
156 list_for_each_entry(entry, &nvs_list, node) {
157 entry->data = (void *)__get_free_page(GFP_KERNEL);
158 if (!entry->data) {
159 suspend_nvs_free();
160 return -ENOMEM;
161 }
162 }
163 return 0;
164}
165
166/**
167 * suspend_nvs_save - save NVS memory regions
168 */
169int suspend_nvs_save(void)
170{
171 struct nvs_page *entry;
172
173 printk(KERN_INFO "PM: Saving platform NVS memory\n");
174
175 list_for_each_entry(entry, &nvs_list, node)
176 if (entry->data) {
177 unsigned long phys = entry->phys_start;
178 unsigned int size = entry->size;
179
180 entry->kaddr = acpi_os_get_iomem(phys, size);
181 if (!entry->kaddr) {
182 entry->kaddr = acpi_os_ioremap(phys, size);
183 entry->unmap = !!entry->kaddr;
184 }
185 if (!entry->kaddr) {
186 suspend_nvs_free();
187 return -ENOMEM;
188 }
189 memcpy(entry->data, entry->kaddr, entry->size);
190 }
191
192 return 0;
193}
194
195/**
196 * suspend_nvs_restore - restore NVS memory regions
197 *
198 * This function is going to be called with interrupts disabled, so it
199 * cannot iounmap the virtual addresses used to access the NVS region.
200 */
201void suspend_nvs_restore(void)
202{
203 struct nvs_page *entry;
204
205 printk(KERN_INFO "PM: Restoring platform NVS memory\n");
206
207 list_for_each_entry(entry, &nvs_list, node)
208 if (entry->data)
209 memcpy(entry->kaddr, entry->data, entry->size);
210}
211#endif
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * nvs.c - Routines for saving and restoring ACPI NVS memory region
4 *
5 * Copyright (C) 2008-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
6 */
7
8#include <linux/io.h>
9#include <linux/kernel.h>
10#include <linux/list.h>
11#include <linux/mm.h>
12#include <linux/slab.h>
13#include <linux/acpi.h>
14
15#include "internal.h"
16
17/* ACPI NVS regions, APEI may use it */
18
19struct nvs_region {
20 __u64 phys_start;
21 __u64 size;
22 struct list_head node;
23};
24
25static LIST_HEAD(nvs_region_list);
26
27#ifdef CONFIG_ACPI_SLEEP
28static int suspend_nvs_register(unsigned long start, unsigned long size);
29#else
30static inline int suspend_nvs_register(unsigned long a, unsigned long b)
31{
32 return 0;
33}
34#endif
35
36int acpi_nvs_register(__u64 start, __u64 size)
37{
38 struct nvs_region *region;
39
40 region = kmalloc(sizeof(*region), GFP_KERNEL);
41 if (!region)
42 return -ENOMEM;
43 region->phys_start = start;
44 region->size = size;
45 list_add_tail(®ion->node, &nvs_region_list);
46
47 return suspend_nvs_register(start, size);
48}
49
50int acpi_nvs_for_each_region(int (*func)(__u64 start, __u64 size, void *data),
51 void *data)
52{
53 int rc;
54 struct nvs_region *region;
55
56 list_for_each_entry(region, &nvs_region_list, node) {
57 rc = func(region->phys_start, region->size, data);
58 if (rc)
59 return rc;
60 }
61
62 return 0;
63}
64
65
66#ifdef CONFIG_ACPI_SLEEP
67/*
68 * Platforms, like ACPI, may want us to save some memory used by them during
69 * suspend and to restore the contents of this memory during the subsequent
70 * resume. The code below implements a mechanism allowing us to do that.
71 */
72
73struct nvs_page {
74 unsigned long phys_start;
75 unsigned int size;
76 void *kaddr;
77 void *data;
78 bool unmap;
79 struct list_head node;
80};
81
82static LIST_HEAD(nvs_list);
83
84/**
85 * suspend_nvs_register - register platform NVS memory region to save
86 * @start - physical address of the region
87 * @size - size of the region
88 *
89 * The NVS region need not be page-aligned (both ends) and we arrange
90 * things so that the data from page-aligned addresses in this region will
91 * be copied into separate RAM pages.
92 */
93static int suspend_nvs_register(unsigned long start, unsigned long size)
94{
95 struct nvs_page *entry, *next;
96
97 pr_info("PM: Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n",
98 start, start + size - 1, size);
99
100 while (size > 0) {
101 unsigned int nr_bytes;
102
103 entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL);
104 if (!entry)
105 goto Error;
106
107 list_add_tail(&entry->node, &nvs_list);
108 entry->phys_start = start;
109 nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK);
110 entry->size = (size < nr_bytes) ? size : nr_bytes;
111
112 start += entry->size;
113 size -= entry->size;
114 }
115 return 0;
116
117 Error:
118 list_for_each_entry_safe(entry, next, &nvs_list, node) {
119 list_del(&entry->node);
120 kfree(entry);
121 }
122 return -ENOMEM;
123}
124
125/**
126 * suspend_nvs_free - free data pages allocated for saving NVS regions
127 */
128void suspend_nvs_free(void)
129{
130 struct nvs_page *entry;
131
132 list_for_each_entry(entry, &nvs_list, node)
133 if (entry->data) {
134 free_page((unsigned long)entry->data);
135 entry->data = NULL;
136 if (entry->kaddr) {
137 if (entry->unmap) {
138 iounmap(entry->kaddr);
139 entry->unmap = false;
140 } else {
141 acpi_os_unmap_iomem(entry->kaddr,
142 entry->size);
143 }
144 entry->kaddr = NULL;
145 }
146 }
147}
148
149/**
150 * suspend_nvs_alloc - allocate memory necessary for saving NVS regions
151 */
152int suspend_nvs_alloc(void)
153{
154 struct nvs_page *entry;
155
156 list_for_each_entry(entry, &nvs_list, node) {
157 entry->data = (void *)__get_free_page(GFP_KERNEL);
158 if (!entry->data) {
159 suspend_nvs_free();
160 return -ENOMEM;
161 }
162 }
163 return 0;
164}
165
166/**
167 * suspend_nvs_save - save NVS memory regions
168 */
169int suspend_nvs_save(void)
170{
171 struct nvs_page *entry;
172
173 printk(KERN_INFO "PM: Saving platform NVS memory\n");
174
175 list_for_each_entry(entry, &nvs_list, node)
176 if (entry->data) {
177 unsigned long phys = entry->phys_start;
178 unsigned int size = entry->size;
179
180 entry->kaddr = acpi_os_get_iomem(phys, size);
181 if (!entry->kaddr) {
182 entry->kaddr = acpi_os_ioremap(phys, size);
183 entry->unmap = !!entry->kaddr;
184 }
185 if (!entry->kaddr) {
186 suspend_nvs_free();
187 return -ENOMEM;
188 }
189 memcpy(entry->data, entry->kaddr, entry->size);
190 }
191
192 return 0;
193}
194
195/**
196 * suspend_nvs_restore - restore NVS memory regions
197 *
198 * This function is going to be called with interrupts disabled, so it
199 * cannot iounmap the virtual addresses used to access the NVS region.
200 */
201void suspend_nvs_restore(void)
202{
203 struct nvs_page *entry;
204
205 printk(KERN_INFO "PM: Restoring platform NVS memory\n");
206
207 list_for_each_entry(entry, &nvs_list, node)
208 if (entry->data)
209 memcpy(entry->kaddr, entry->data, entry->size);
210}
211#endif