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1/*
2 * nvs.c - Routines for saving and restoring ACPI NVS memory region
3 *
4 * Copyright (C) 2008-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
5 *
6 * This file is released under the GPLv2.
7 */
8
9#include <linux/io.h>
10#include <linux/kernel.h>
11#include <linux/list.h>
12#include <linux/mm.h>
13#include <linux/slab.h>
14#include <linux/acpi.h>
15#include <linux/acpi_io.h>
16#include <acpi/acpiosxf.h>
17
18/*
19 * Platforms, like ACPI, may want us to save some memory used by them during
20 * suspend and to restore the contents of this memory during the subsequent
21 * resume. The code below implements a mechanism allowing us to do that.
22 */
23
24struct nvs_page {
25 unsigned long phys_start;
26 unsigned int size;
27 void *kaddr;
28 void *data;
29 bool unmap;
30 struct list_head node;
31};
32
33static LIST_HEAD(nvs_list);
34
35/**
36 * suspend_nvs_register - register platform NVS memory region to save
37 * @start - physical address of the region
38 * @size - size of the region
39 *
40 * The NVS region need not be page-aligned (both ends) and we arrange
41 * things so that the data from page-aligned addresses in this region will
42 * be copied into separate RAM pages.
43 */
44int suspend_nvs_register(unsigned long start, unsigned long size)
45{
46 struct nvs_page *entry, *next;
47
48 pr_info("PM: Registering ACPI NVS region at %lx (%ld bytes)\n",
49 start, size);
50
51 while (size > 0) {
52 unsigned int nr_bytes;
53
54 entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL);
55 if (!entry)
56 goto Error;
57
58 list_add_tail(&entry->node, &nvs_list);
59 entry->phys_start = start;
60 nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK);
61 entry->size = (size < nr_bytes) ? size : nr_bytes;
62
63 start += entry->size;
64 size -= entry->size;
65 }
66 return 0;
67
68 Error:
69 list_for_each_entry_safe(entry, next, &nvs_list, node) {
70 list_del(&entry->node);
71 kfree(entry);
72 }
73 return -ENOMEM;
74}
75
76/**
77 * suspend_nvs_free - free data pages allocated for saving NVS regions
78 */
79void suspend_nvs_free(void)
80{
81 struct nvs_page *entry;
82
83 list_for_each_entry(entry, &nvs_list, node)
84 if (entry->data) {
85 free_page((unsigned long)entry->data);
86 entry->data = NULL;
87 if (entry->kaddr) {
88 if (entry->unmap) {
89 iounmap(entry->kaddr);
90 entry->unmap = false;
91 } else {
92 acpi_os_unmap_memory(entry->kaddr,
93 entry->size);
94 }
95 entry->kaddr = NULL;
96 }
97 }
98}
99
100/**
101 * suspend_nvs_alloc - allocate memory necessary for saving NVS regions
102 */
103int suspend_nvs_alloc(void)
104{
105 struct nvs_page *entry;
106
107 list_for_each_entry(entry, &nvs_list, node) {
108 entry->data = (void *)__get_free_page(GFP_KERNEL);
109 if (!entry->data) {
110 suspend_nvs_free();
111 return -ENOMEM;
112 }
113 }
114 return 0;
115}
116
117/**
118 * suspend_nvs_save - save NVS memory regions
119 */
120int suspend_nvs_save(void)
121{
122 struct nvs_page *entry;
123
124 printk(KERN_INFO "PM: Saving platform NVS memory\n");
125
126 list_for_each_entry(entry, &nvs_list, node)
127 if (entry->data) {
128 unsigned long phys = entry->phys_start;
129 unsigned int size = entry->size;
130
131 entry->kaddr = acpi_os_get_iomem(phys, size);
132 if (!entry->kaddr) {
133 entry->kaddr = acpi_os_ioremap(phys, size);
134 entry->unmap = !!entry->kaddr;
135 }
136 if (!entry->kaddr) {
137 suspend_nvs_free();
138 return -ENOMEM;
139 }
140 memcpy(entry->data, entry->kaddr, entry->size);
141 }
142
143 return 0;
144}
145
146/**
147 * suspend_nvs_restore - restore NVS memory regions
148 *
149 * This function is going to be called with interrupts disabled, so it
150 * cannot iounmap the virtual addresses used to access the NVS region.
151 */
152void suspend_nvs_restore(void)
153{
154 struct nvs_page *entry;
155
156 printk(KERN_INFO "PM: Restoring platform NVS memory\n");
157
158 list_for_each_entry(entry, &nvs_list, node)
159 if (entry->data)
160 memcpy(entry->kaddr, entry->data, entry->size);
161}
1/*
2 * nvs.c - Routines for saving and restoring ACPI NVS memory region
3 *
4 * Copyright (C) 2008-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
5 *
6 * This file is released under the GPLv2.
7 */
8
9#include <linux/io.h>
10#include <linux/kernel.h>
11#include <linux/list.h>
12#include <linux/mm.h>
13#include <linux/slab.h>
14#include <linux/acpi.h>
15#include <linux/acpi_io.h>
16#include <acpi/acpiosxf.h>
17
18/* ACPI NVS regions, APEI may use it */
19
20struct nvs_region {
21 __u64 phys_start;
22 __u64 size;
23 struct list_head node;
24};
25
26static LIST_HEAD(nvs_region_list);
27
28#ifdef CONFIG_ACPI_SLEEP
29static int suspend_nvs_register(unsigned long start, unsigned long size);
30#else
31static inline int suspend_nvs_register(unsigned long a, unsigned long b)
32{
33 return 0;
34}
35#endif
36
37int acpi_nvs_register(__u64 start, __u64 size)
38{
39 struct nvs_region *region;
40
41 region = kmalloc(sizeof(*region), GFP_KERNEL);
42 if (!region)
43 return -ENOMEM;
44 region->phys_start = start;
45 region->size = size;
46 list_add_tail(®ion->node, &nvs_region_list);
47
48 return suspend_nvs_register(start, size);
49}
50
51int acpi_nvs_for_each_region(int (*func)(__u64 start, __u64 size, void *data),
52 void *data)
53{
54 int rc;
55 struct nvs_region *region;
56
57 list_for_each_entry(region, &nvs_region_list, node) {
58 rc = func(region->phys_start, region->size, data);
59 if (rc)
60 return rc;
61 }
62
63 return 0;
64}
65
66
67#ifdef CONFIG_ACPI_SLEEP
68/*
69 * Platforms, like ACPI, may want us to save some memory used by them during
70 * suspend and to restore the contents of this memory during the subsequent
71 * resume. The code below implements a mechanism allowing us to do that.
72 */
73
74struct nvs_page {
75 unsigned long phys_start;
76 unsigned int size;
77 void *kaddr;
78 void *data;
79 bool unmap;
80 struct list_head node;
81};
82
83static LIST_HEAD(nvs_list);
84
85/**
86 * suspend_nvs_register - register platform NVS memory region to save
87 * @start - physical address of the region
88 * @size - size of the region
89 *
90 * The NVS region need not be page-aligned (both ends) and we arrange
91 * things so that the data from page-aligned addresses in this region will
92 * be copied into separate RAM pages.
93 */
94static int suspend_nvs_register(unsigned long start, unsigned long size)
95{
96 struct nvs_page *entry, *next;
97
98 pr_info("PM: Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n",
99 start, start + size - 1, size);
100
101 while (size > 0) {
102 unsigned int nr_bytes;
103
104 entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL);
105 if (!entry)
106 goto Error;
107
108 list_add_tail(&entry->node, &nvs_list);
109 entry->phys_start = start;
110 nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK);
111 entry->size = (size < nr_bytes) ? size : nr_bytes;
112
113 start += entry->size;
114 size -= entry->size;
115 }
116 return 0;
117
118 Error:
119 list_for_each_entry_safe(entry, next, &nvs_list, node) {
120 list_del(&entry->node);
121 kfree(entry);
122 }
123 return -ENOMEM;
124}
125
126/**
127 * suspend_nvs_free - free data pages allocated for saving NVS regions
128 */
129void suspend_nvs_free(void)
130{
131 struct nvs_page *entry;
132
133 list_for_each_entry(entry, &nvs_list, node)
134 if (entry->data) {
135 free_page((unsigned long)entry->data);
136 entry->data = NULL;
137 if (entry->kaddr) {
138 if (entry->unmap) {
139 iounmap(entry->kaddr);
140 entry->unmap = false;
141 } else {
142 acpi_os_unmap_memory(entry->kaddr,
143 entry->size);
144 }
145 entry->kaddr = NULL;
146 }
147 }
148}
149
150/**
151 * suspend_nvs_alloc - allocate memory necessary for saving NVS regions
152 */
153int suspend_nvs_alloc(void)
154{
155 struct nvs_page *entry;
156
157 list_for_each_entry(entry, &nvs_list, node) {
158 entry->data = (void *)__get_free_page(GFP_KERNEL);
159 if (!entry->data) {
160 suspend_nvs_free();
161 return -ENOMEM;
162 }
163 }
164 return 0;
165}
166
167/**
168 * suspend_nvs_save - save NVS memory regions
169 */
170int suspend_nvs_save(void)
171{
172 struct nvs_page *entry;
173
174 printk(KERN_INFO "PM: Saving platform NVS memory\n");
175
176 list_for_each_entry(entry, &nvs_list, node)
177 if (entry->data) {
178 unsigned long phys = entry->phys_start;
179 unsigned int size = entry->size;
180
181 entry->kaddr = acpi_os_get_iomem(phys, size);
182 if (!entry->kaddr) {
183 entry->kaddr = acpi_os_ioremap(phys, size);
184 entry->unmap = !!entry->kaddr;
185 }
186 if (!entry->kaddr) {
187 suspend_nvs_free();
188 return -ENOMEM;
189 }
190 memcpy(entry->data, entry->kaddr, entry->size);
191 }
192
193 return 0;
194}
195
196/**
197 * suspend_nvs_restore - restore NVS memory regions
198 *
199 * This function is going to be called with interrupts disabled, so it
200 * cannot iounmap the virtual addresses used to access the NVS region.
201 */
202void suspend_nvs_restore(void)
203{
204 struct nvs_page *entry;
205
206 printk(KERN_INFO "PM: Restoring platform NVS memory\n");
207
208 list_for_each_entry(entry, &nvs_list, node)
209 if (entry->data)
210 memcpy(entry->kaddr, entry->data, entry->size);
211}
212#endif