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55716d26 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
fce2b111 | 2 | /* |
d146df18 | 3 | * nvs.c - Routines for saving and restoring ACPI NVS memory region |
fce2b111 | 4 | * |
d146df18 | 5 | * Copyright (C) 2008-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. |
fce2b111 CH |
6 | */ |
7 | ||
8 | #include <linux/io.h> | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/list.h> | |
11 | #include <linux/mm.h> | |
5a0e3ad6 | 12 | #include <linux/slab.h> |
d146df18 | 13 | #include <linux/acpi.h> |
fce2b111 | 14 | |
679c581b R |
15 | #include "internal.h" |
16 | ||
b54ac6d2 HY |
17 | /* ACPI NVS regions, APEI may use it */ |
18 | ||
19 | struct nvs_region { | |
20 | __u64 phys_start; | |
21 | __u64 size; | |
22 | struct list_head node; | |
23 | }; | |
24 | ||
25 | static LIST_HEAD(nvs_region_list); | |
26 | ||
27 | #ifdef CONFIG_ACPI_SLEEP | |
28 | static int suspend_nvs_register(unsigned long start, unsigned long size); | |
29 | #else | |
30 | static inline int suspend_nvs_register(unsigned long a, unsigned long b) | |
31 | { | |
32 | return 0; | |
33 | } | |
34 | #endif | |
35 | ||
36 | int 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 | ||
50 | int 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 | |
fce2b111 CH |
67 | /* |
68 | * Platforms, like ACPI, may want us to save some memory used by them during | |
dd4c4f17 | 69 | * suspend and to restore the contents of this memory during the subsequent |
fce2b111 CH |
70 | * resume. The code below implements a mechanism allowing us to do that. |
71 | */ | |
72 | ||
73 | struct nvs_page { | |
74 | unsigned long phys_start; | |
75 | unsigned int size; | |
76 | void *kaddr; | |
77 | void *data; | |
bb45e394 | 78 | bool unmap; |
fce2b111 CH |
79 | struct list_head node; |
80 | }; | |
81 | ||
82 | static LIST_HEAD(nvs_list); | |
83 | ||
84 | /** | |
dd4c4f17 | 85 | * suspend_nvs_register - register platform NVS memory region to save |
fce2b111 CH |
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 | */ | |
b54ac6d2 | 93 | static int suspend_nvs_register(unsigned long start, unsigned long size) |
fce2b111 CH |
94 | { |
95 | struct nvs_page *entry, *next; | |
96 | ||
c6436f5a BH |
97 | pr_info("PM: Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n", |
98 | start, start + size - 1, size); | |
bb45e394 | 99 | |
fce2b111 CH |
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 | /** | |
dd4c4f17 | 126 | * suspend_nvs_free - free data pages allocated for saving NVS regions |
fce2b111 | 127 | */ |
dd4c4f17 | 128 | void suspend_nvs_free(void) |
fce2b111 CH |
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) { | |
bb45e394 RW |
137 | if (entry->unmap) { |
138 | iounmap(entry->kaddr); | |
139 | entry->unmap = false; | |
140 | } else { | |
a238317c LZ |
141 | acpi_os_unmap_iomem(entry->kaddr, |
142 | entry->size); | |
bb45e394 | 143 | } |
fce2b111 CH |
144 | entry->kaddr = NULL; |
145 | } | |
146 | } | |
147 | } | |
148 | ||
149 | /** | |
dd4c4f17 | 150 | * suspend_nvs_alloc - allocate memory necessary for saving NVS regions |
fce2b111 | 151 | */ |
dd4c4f17 | 152 | int suspend_nvs_alloc(void) |
fce2b111 CH |
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) { | |
dd4c4f17 | 159 | suspend_nvs_free(); |
fce2b111 CH |
160 | return -ENOMEM; |
161 | } | |
162 | } | |
163 | return 0; | |
164 | } | |
165 | ||
166 | /** | |
dd4c4f17 | 167 | * suspend_nvs_save - save NVS memory regions |
fce2b111 | 168 | */ |
26fcaf60 | 169 | int suspend_nvs_save(void) |
fce2b111 CH |
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) { | |
bb45e394 RW |
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 | } | |
26fcaf60 JS |
185 | if (!entry->kaddr) { |
186 | suspend_nvs_free(); | |
187 | return -ENOMEM; | |
188 | } | |
fce2b111 CH |
189 | memcpy(entry->data, entry->kaddr, entry->size); |
190 | } | |
26fcaf60 JS |
191 | |
192 | return 0; | |
fce2b111 CH |
193 | } |
194 | ||
195 | /** | |
dd4c4f17 | 196 | * suspend_nvs_restore - restore NVS memory regions |
fce2b111 CH |
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 | */ | |
dd4c4f17 | 201 | void suspend_nvs_restore(void) |
fce2b111 CH |
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 | } | |
b54ac6d2 | 211 | #endif |