diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-12 13:17:27 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-12 13:17:27 -0700 |
commit | 947ec0b0c1e7e80eef4fe64f7763a06d0cf04d2e (patch) | |
tree | 29547b6975d58c3b252f08dc6c2dbda3b9adfa88 /kernel/power/hibernate_nvs.c | |
parent | c53567ad4528b6efefc3fc22a354d20f6226a098 (diff) | |
parent | 5818a6e2519b34cd6d0220d89f5729ab2725e1bf (diff) |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
PM: Add empty suspend/resume device irq functions
PM/Hibernate: Move NVS routines into a seperate file (v2).
PM/Hibernate: Rename disk.c to hibernate.c
PM: Separate suspend to RAM functionality from core
Driver Core: Rework platform suspend/resume, print warning
PM: Remove device_type suspend()/resume()
PM/Hibernate: Move memory shrinking to snapshot.c (rev. 2)
PM/Suspend: Do not shrink memory before suspend
PM: Remove bus_type suspend_late()/resume_early() V2
PM core: rename suspend and resume functions
PM: Rename device_power_down/up()
PM: Remove unused asm/suspend.h
x86: unify power/cpu_(32|64).c
x86: unify power/cpu_(32|64) copyright notes
x86: unify power/cpu_(32|64) regarding restoring processor state
x86: unify power/cpu_(32|64) regarding saving processor state
x86: unify power/cpu_(32|64) global variables
x86: unify power/cpu_(32|64) headers
PM: Warn if interrupts are enabled during suspend-resume of sysdevs
PM/ACPI/x86: Fix sparse warning in arch/x86/kernel/acpi/sleep.c
Diffstat (limited to 'kernel/power/hibernate_nvs.c')
-rw-r--r-- | kernel/power/hibernate_nvs.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/kernel/power/hibernate_nvs.c b/kernel/power/hibernate_nvs.c new file mode 100644 index 00000000000..39ac698ef83 --- /dev/null +++ b/kernel/power/hibernate_nvs.c @@ -0,0 +1,135 @@ +/* + * linux/kernel/power/hibernate_nvs.c - Routines for handling NVS memory + * + * Copyright (C) 2008,2009 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. + * + * This file is released under the GPLv2. + */ + +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/mm.h> +#include <linux/suspend.h> + +/* + * Platforms, like ACPI, may want us to save some memory used by them during + * hibernation and to restore the contents of this memory during the subsequent + * resume. The code below implements a mechanism allowing us to do that. + */ + +struct nvs_page { + unsigned long phys_start; + unsigned int size; + void *kaddr; + void *data; + struct list_head node; +}; + +static LIST_HEAD(nvs_list); + +/** + * hibernate_nvs_register - register platform NVS memory region to save + * @start - physical address of the region + * @size - size of the region + * + * The NVS region need not be page-aligned (both ends) and we arrange + * things so that the data from page-aligned addresses in this region will + * be copied into separate RAM pages. + */ +int hibernate_nvs_register(unsigned long start, unsigned long size) +{ + struct nvs_page *entry, *next; + + while (size > 0) { + unsigned int nr_bytes; + + entry = kzalloc(sizeof(struct nvs_page), GFP_KERNEL); + if (!entry) + goto Error; + + list_add_tail(&entry->node, &nvs_list); + entry->phys_start = start; + nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK); + entry->size = (size < nr_bytes) ? size : nr_bytes; + + start += entry->size; + size -= entry->size; + } + return 0; + + Error: + list_for_each_entry_safe(entry, next, &nvs_list, node) { + list_del(&entry->node); + kfree(entry); + } + return -ENOMEM; +} + +/** + * hibernate_nvs_free - free data pages allocated for saving NVS regions + */ +void hibernate_nvs_free(void) +{ + struct nvs_page *entry; + + list_for_each_entry(entry, &nvs_list, node) + if (entry->data) { + free_page((unsigned long)entry->data); + entry->data = NULL; + if (entry->kaddr) { + iounmap(entry->kaddr); + entry->kaddr = NULL; + } + } +} + +/** + * hibernate_nvs_alloc - allocate memory necessary for saving NVS regions + */ +int hibernate_nvs_alloc(void) +{ + struct nvs_page *entry; + + list_for_each_entry(entry, &nvs_list, node) { + entry->data = (void *)__get_free_page(GFP_KERNEL); + if (!entry->data) { + hibernate_nvs_free(); + return -ENOMEM; + } + } + return 0; +} + +/** + * hibernate_nvs_save - save NVS memory regions + */ +void hibernate_nvs_save(void) +{ + struct nvs_page *entry; + + printk(KERN_INFO "PM: Saving platform NVS memory\n"); + + list_for_each_entry(entry, &nvs_list, node) + if (entry->data) { + entry->kaddr = ioremap(entry->phys_start, entry->size); + memcpy(entry->data, entry->kaddr, entry->size); + } +} + +/** + * hibernate_nvs_restore - restore NVS memory regions + * + * This function is going to be called with interrupts disabled, so it + * cannot iounmap the virtual addresses used to access the NVS region. + */ +void hibernate_nvs_restore(void) +{ + struct nvs_page *entry; + + printk(KERN_INFO "PM: Restoring platform NVS memory\n"); + + list_for_each_entry(entry, &nvs_list, node) + if (entry->data) + memcpy(entry->kaddr, entry->data, entry->size); +} |