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

["Rafael J. Wysocki" <rjw@sisk.pl>]

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@de.ibm.com>

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@sisk.pl>, 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