Bluetooth: hci_serdev: Init hci_uart proto_lock to avoid oops
[linux/fpc-iii.git] / drivers / acpi / nvs.c
blob85287b8fe3aa4923ef9d37739d567e5ed4ef86ad
1 /*
2 * nvs.c - Routines for saving and restoring ACPI NVS memory region
4 * Copyright (C) 2008-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc.
6 * This file is released under the GPLv2.
7 */
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>
16 #include "internal.h"
18 /* ACPI NVS regions, APEI may use it */
20 struct nvs_region {
21 __u64 phys_start;
22 __u64 size;
23 struct list_head node;
26 static LIST_HEAD(nvs_region_list);
28 #ifdef CONFIG_ACPI_SLEEP
29 static int suspend_nvs_register(unsigned long start, unsigned long size);
30 #else
31 static inline int suspend_nvs_register(unsigned long a, unsigned long b)
33 return 0;
35 #endif
37 int acpi_nvs_register(__u64 start, __u64 size)
39 struct nvs_region *region;
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(&region->node, &nvs_region_list);
48 return suspend_nvs_register(start, size);
51 int acpi_nvs_for_each_region(int (*func)(__u64 start, __u64 size, void *data),
52 void *data)
54 int rc;
55 struct nvs_region *region;
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;
63 return 0;
67 #ifdef CONFIG_ACPI_SLEEP
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.
74 struct 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;
83 static LIST_HEAD(nvs_list);
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
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.
94 static int suspend_nvs_register(unsigned long start, unsigned long size)
96 struct nvs_page *entry, *next;
98 pr_info("PM: Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n",
99 start, start + size - 1, size);
101 while (size > 0) {
102 unsigned int nr_bytes;
104 entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL);
105 if (!entry)
106 goto Error;
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;
113 start += entry->size;
114 size -= entry->size;
116 return 0;
118 Error:
119 list_for_each_entry_safe(entry, next, &nvs_list, node) {
120 list_del(&entry->node);
121 kfree(entry);
123 return -ENOMEM;
127 * suspend_nvs_free - free data pages allocated for saving NVS regions
129 void suspend_nvs_free(void)
131 struct nvs_page *entry;
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_iomem(entry->kaddr,
143 entry->size);
145 entry->kaddr = NULL;
151 * suspend_nvs_alloc - allocate memory necessary for saving NVS regions
153 int suspend_nvs_alloc(void)
155 struct nvs_page *entry;
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;
164 return 0;
168 * suspend_nvs_save - save NVS memory regions
170 int suspend_nvs_save(void)
172 struct nvs_page *entry;
174 printk(KERN_INFO "PM: Saving platform NVS memory\n");
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;
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;
186 if (!entry->kaddr) {
187 suspend_nvs_free();
188 return -ENOMEM;
190 memcpy(entry->data, entry->kaddr, entry->size);
193 return 0;
197 * suspend_nvs_restore - restore NVS memory regions
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.
202 void suspend_nvs_restore(void)
204 struct nvs_page *entry;
206 printk(KERN_INFO "PM: Restoring platform NVS memory\n");
208 list_for_each_entry(entry, &nvs_list, node)
209 if (entry->data)
210 memcpy(entry->kaddr, entry->data, entry->size);
212 #endif