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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 | ||
4f59927d HG |
8 | #define pr_fmt(fmt) "ACPI: PM: " fmt |
9 | ||
fce2b111 CH |
10 | #include <linux/io.h> |
11 | #include <linux/kernel.h> | |
12 | #include <linux/list.h> | |
13 | #include <linux/mm.h> | |
5a0e3ad6 | 14 | #include <linux/slab.h> |
d146df18 | 15 | #include <linux/acpi.h> |
fce2b111 | 16 | |
679c581b R |
17 | #include "internal.h" |
18 | ||
b54ac6d2 HY |
19 | /* ACPI NVS regions, APEI may use it */ |
20 | ||
21 | struct nvs_region { | |
22 | __u64 phys_start; | |
23 | __u64 size; | |
24 | struct list_head node; | |
25 | }; | |
26 | ||
27 | static LIST_HEAD(nvs_region_list); | |
28 | ||
29 | #ifdef CONFIG_ACPI_SLEEP | |
30 | static int suspend_nvs_register(unsigned long start, unsigned long size); | |
31 | #else | |
32 | static inline int suspend_nvs_register(unsigned long a, unsigned long b) | |
33 | { | |
34 | return 0; | |
35 | } | |
36 | #endif | |
37 | ||
38 | int acpi_nvs_register(__u64 start, __u64 size) | |
39 | { | |
40 | struct nvs_region *region; | |
41 | ||
42 | region = kmalloc(sizeof(*region), GFP_KERNEL); | |
43 | if (!region) | |
44 | return -ENOMEM; | |
45 | region->phys_start = start; | |
46 | region->size = size; | |
47 | list_add_tail(®ion->node, &nvs_region_list); | |
48 | ||
49 | return suspend_nvs_register(start, size); | |
50 | } | |
51 | ||
52 | int acpi_nvs_for_each_region(int (*func)(__u64 start, __u64 size, void *data), | |
53 | void *data) | |
54 | { | |
55 | int rc; | |
56 | struct nvs_region *region; | |
57 | ||
58 | list_for_each_entry(region, &nvs_region_list, node) { | |
59 | rc = func(region->phys_start, region->size, data); | |
60 | if (rc) | |
61 | return rc; | |
62 | } | |
63 | ||
64 | return 0; | |
65 | } | |
66 | ||
67 | ||
68 | #ifdef CONFIG_ACPI_SLEEP | |
fce2b111 CH |
69 | /* |
70 | * Platforms, like ACPI, may want us to save some memory used by them during | |
dd4c4f17 | 71 | * suspend and to restore the contents of this memory during the subsequent |
fce2b111 CH |
72 | * resume. The code below implements a mechanism allowing us to do that. |
73 | */ | |
74 | ||
75 | struct nvs_page { | |
76 | unsigned long phys_start; | |
77 | unsigned int size; | |
78 | void *kaddr; | |
79 | void *data; | |
bb45e394 | 80 | bool unmap; |
fce2b111 CH |
81 | struct list_head node; |
82 | }; | |
83 | ||
84 | static LIST_HEAD(nvs_list); | |
85 | ||
86 | /** | |
120f4aa8 BL |
87 | * suspend_nvs_register - register platform NVS memory region to save |
88 | * @start: Physical address of the region. | |
89 | * @size: Size of the region. | |
fce2b111 | 90 | * |
120f4aa8 BL |
91 | * The NVS region need not be page-aligned (both ends) and we arrange |
92 | * things so that the data from page-aligned addresses in this region will | |
93 | * be copied into separate RAM pages. | |
fce2b111 | 94 | */ |
b54ac6d2 | 95 | static int suspend_nvs_register(unsigned long start, unsigned long size) |
fce2b111 CH |
96 | { |
97 | struct nvs_page *entry, *next; | |
98 | ||
4f59927d | 99 | pr_info("Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n", |
c6436f5a | 100 | start, start + size - 1, size); |
bb45e394 | 101 | |
fce2b111 CH |
102 | while (size > 0) { |
103 | unsigned int nr_bytes; | |
104 | ||
105 | entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL); | |
106 | if (!entry) | |
107 | goto Error; | |
108 | ||
109 | list_add_tail(&entry->node, &nvs_list); | |
110 | entry->phys_start = start; | |
111 | nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK); | |
112 | entry->size = (size < nr_bytes) ? size : nr_bytes; | |
113 | ||
114 | start += entry->size; | |
115 | size -= entry->size; | |
116 | } | |
117 | return 0; | |
118 | ||
119 | Error: | |
120 | list_for_each_entry_safe(entry, next, &nvs_list, node) { | |
121 | list_del(&entry->node); | |
122 | kfree(entry); | |
123 | } | |
124 | return -ENOMEM; | |
125 | } | |
126 | ||
127 | /** | |
120f4aa8 | 128 | * suspend_nvs_free - free data pages allocated for saving NVS regions |
fce2b111 | 129 | */ |
dd4c4f17 | 130 | void suspend_nvs_free(void) |
fce2b111 CH |
131 | { |
132 | struct nvs_page *entry; | |
133 | ||
134 | list_for_each_entry(entry, &nvs_list, node) | |
135 | if (entry->data) { | |
136 | free_page((unsigned long)entry->data); | |
137 | entry->data = NULL; | |
138 | if (entry->kaddr) { | |
bb45e394 RW |
139 | if (entry->unmap) { |
140 | iounmap(entry->kaddr); | |
141 | entry->unmap = false; | |
142 | } else { | |
a238317c LZ |
143 | acpi_os_unmap_iomem(entry->kaddr, |
144 | entry->size); | |
bb45e394 | 145 | } |
fce2b111 CH |
146 | entry->kaddr = NULL; |
147 | } | |
148 | } | |
149 | } | |
150 | ||
151 | /** | |
120f4aa8 | 152 | * suspend_nvs_alloc - allocate memory necessary for saving NVS regions |
fce2b111 | 153 | */ |
dd4c4f17 | 154 | int suspend_nvs_alloc(void) |
fce2b111 CH |
155 | { |
156 | struct nvs_page *entry; | |
157 | ||
158 | list_for_each_entry(entry, &nvs_list, node) { | |
159 | entry->data = (void *)__get_free_page(GFP_KERNEL); | |
160 | if (!entry->data) { | |
dd4c4f17 | 161 | suspend_nvs_free(); |
fce2b111 CH |
162 | return -ENOMEM; |
163 | } | |
164 | } | |
165 | return 0; | |
166 | } | |
167 | ||
168 | /** | |
120f4aa8 | 169 | * suspend_nvs_save - save NVS memory regions |
fce2b111 | 170 | */ |
26fcaf60 | 171 | int suspend_nvs_save(void) |
fce2b111 CH |
172 | { |
173 | struct nvs_page *entry; | |
174 | ||
4f59927d | 175 | pr_info("Saving platform NVS memory\n"); |
fce2b111 CH |
176 | |
177 | list_for_each_entry(entry, &nvs_list, node) | |
178 | if (entry->data) { | |
bb45e394 RW |
179 | unsigned long phys = entry->phys_start; |
180 | unsigned int size = entry->size; | |
181 | ||
182 | entry->kaddr = acpi_os_get_iomem(phys, size); | |
183 | if (!entry->kaddr) { | |
184 | entry->kaddr = acpi_os_ioremap(phys, size); | |
185 | entry->unmap = !!entry->kaddr; | |
186 | } | |
26fcaf60 JS |
187 | if (!entry->kaddr) { |
188 | suspend_nvs_free(); | |
189 | return -ENOMEM; | |
190 | } | |
fce2b111 CH |
191 | memcpy(entry->data, entry->kaddr, entry->size); |
192 | } | |
26fcaf60 JS |
193 | |
194 | return 0; | |
fce2b111 CH |
195 | } |
196 | ||
197 | /** | |
120f4aa8 | 198 | * suspend_nvs_restore - restore NVS memory regions |
fce2b111 | 199 | * |
120f4aa8 BL |
200 | * This function is going to be called with interrupts disabled, so it |
201 | * cannot iounmap the virtual addresses used to access the NVS region. | |
fce2b111 | 202 | */ |
dd4c4f17 | 203 | void suspend_nvs_restore(void) |
fce2b111 CH |
204 | { |
205 | struct nvs_page *entry; | |
206 | ||
4f59927d | 207 | pr_info("Restoring platform NVS memory\n"); |
fce2b111 CH |
208 | |
209 | list_for_each_entry(entry, &nvs_list, node) | |
210 | if (entry->data) | |
211 | memcpy(entry->kaddr, entry->data, entry->size); | |
212 | } | |
b54ac6d2 | 213 | #endif |