Re: [PATCH v2] pm: Move nvs routines into a seperate file.

From: Rafael J. Wysocki
Date: Tue Jun 09 2009 - 19:10:00 EST


On Tuesday 09 June 2009, Cornelia Huck wrote:
> The *_nvs_* routines in swsusp.c make use of the io*map()
> functions, which are only provided for HAS_IOMEM, thus
> breaking compilation if HAS_IOMEM is not set. Fix this
> by moving the *_nvs_* routines into hibernation_nvs.c, which
> is only compiled if HAS_IOMEM is set.
>
> Signed-off-by: Cornelia Huck <cornelia.huck@xxxxxxxxxx>

Thanks, I added the GPLv2 line to the header comment and changed the name
of the file to hibernate_nvs.c (to match the other changes in the works).

I'll carry out some compilation testing on it and put it into the tree shortly.

Best,
Rafael

> ---
> include/linux/suspend.h | 18 +++--
> kernel/power/Kconfig | 4 +
> kernel/power/Makefile | 1
> kernel/power/hibernation_nvs.c | 135 +++++++++++++++++++++++++++++++++++++++++
> kernel/power/swsusp.c | 122 -------------------------------------
> 5 files changed, 151 insertions(+), 129 deletions(-)
>
> --- /dev/null
> +++ linux-suspend/kernel/power/hibernation_nvs.c
> @@ -0,0 +1,135 @@
> +/*
> + * linux/kernel/power/hibernation_nvs.c
> + *
> + * Copyright (C) 2008,2009 Rafael J. Wysocki <rjw@xxxxxxx>, Novell Inc.
> + *
> + * Routines for NVS memory handling
> + */
> +
> +#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);
> +}
> --- linux-suspend.orig/kernel/power/swsusp.c
> +++ linux-suspend/kernel/power/swsusp.c
> @@ -186,125 +186,3 @@ void swsusp_show_speed(struct timeval *s
> centisecs / 100, centisecs % 100,
> kps / 1000, (kps % 1000) / 10);
> }
> -
> -/*
> - * 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);
> -}
> --- linux-suspend.orig/kernel/power/Kconfig
> +++ linux-suspend/kernel/power/Kconfig
> @@ -116,9 +116,13 @@ config SUSPEND_FREEZER
>
> Turning OFF this setting is NOT recommended! If in doubt, say Y.
>
> +config HIBERNATION_NVS
> + bool
> +
> config HIBERNATION
> bool "Hibernation (aka 'suspend to disk')"
> depends on PM && SWAP && ARCH_HIBERNATION_POSSIBLE
> + select HIBERNATION_NVS if HAS_IOMEM
> ---help---
> Enable the suspend to disk (STD) functionality, which is usually
> called "hibernation" in user interfaces. STD checkpoints the
> --- linux-suspend.orig/kernel/power/Makefile
> +++ linux-suspend/kernel/power/Makefile
> @@ -7,5 +7,6 @@ obj-$(CONFIG_PM) += main.o
> obj-$(CONFIG_PM_SLEEP) += console.o
> obj-$(CONFIG_FREEZER) += process.o
> obj-$(CONFIG_HIBERNATION) += swsusp.o disk.o snapshot.o swap.o user.o
> +obj-$(CONFIG_HIBERNATION_NVS) += hibernation_nvs.o
>
> obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.o
> --- linux-suspend.orig/include/linux/suspend.h
> +++ linux-suspend/include/linux/suspend.h
> @@ -245,11 +245,6 @@ extern unsigned long get_safe_page(gfp_t
>
> extern void hibernation_set_ops(struct platform_hibernation_ops *ops);
> extern int hibernate(void);
> -extern int hibernate_nvs_register(unsigned long start, unsigned long size);
> -extern int hibernate_nvs_alloc(void);
> -extern void hibernate_nvs_free(void);
> -extern void hibernate_nvs_save(void);
> -extern void hibernate_nvs_restore(void);
> extern bool system_entering_hibernation(void);
> #else /* CONFIG_HIBERNATION */
> static inline int swsusp_page_is_forbidden(struct page *p) { return 0; }
> @@ -258,6 +253,16 @@ static inline void swsusp_unset_page_fre
>
> static inline void hibernation_set_ops(struct platform_hibernation_ops *ops) {}
> static inline int hibernate(void) { return -ENOSYS; }
> +static inline bool system_entering_hibernation(void) { return false; }
> +#endif /* CONFIG_HIBERNATION */
> +
> +#ifdef CONFIG_HIBERNATION_NVS
> +extern int hibernate_nvs_register(unsigned long start, unsigned long size);
> +extern int hibernate_nvs_alloc(void);
> +extern void hibernate_nvs_free(void);
> +extern void hibernate_nvs_save(void);
> +extern void hibernate_nvs_restore(void);
> +#else /* CONFIG_HIBERNATION_NVS */
> static inline int hibernate_nvs_register(unsigned long a, unsigned long b)
> {
> return 0;
> @@ -266,8 +271,7 @@ static inline int hibernate_nvs_alloc(vo
> static inline void hibernate_nvs_free(void) {}
> static inline void hibernate_nvs_save(void) {}
> static inline void hibernate_nvs_restore(void) {}
> -static inline bool system_entering_hibernation(void) { return false; }
> -#endif /* CONFIG_HIBERNATION */
> +#endif /* CONFIG_HIBERNATION_NVS */
>
> #ifdef CONFIG_PM_SLEEP
> void save_processor_state(void);
>
>


--
Everyone knows that debugging is twice as hard as writing a program
in the first place. So if you're as clever as you can be when you write it,
how will you ever debug it? --- Brian Kernighan
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