Re: [PATCH 1/3] swsusp add architecture special saveable pagessupport

[Shaohua Li]

On Wed, 2006-04-12 at 06:55 +0200, Pavel Machek wrote:
> > 
> > 1. Add architecture specific pages save/restore support. Next two patches will
> > use this to save/restore 'ACPI NVS' pages.
> > 2. Allow reserved pages 'nosave'. This could avoid save/restore BIOS reserved
> > pages.
> 
> I'm not 100% convinced that it is needed, but if BIOS people say it
> is, lets believe them. Code looks ok.
ACPI spec 3.0 also says in P387, P405 reserved pages should not be
saved/restored and ACPI NVS should be saved/restored in S4.

Thanks,
Shaohua
> 
> 							Pavel
> > 
> > Signed-off-by: Shaohua Li <shaohua.li@xxxxxxxxx>
> > ---
> > 
> >  linux-2.6.17-rc1-root/include/linux/suspend.h |    1 
> >  linux-2.6.17-rc1-root/kernel/power/power.h    |    4 +
> >  linux-2.6.17-rc1-root/kernel/power/snapshot.c |  100 +++++++++++++++++++++++++-
> >  linux-2.6.17-rc1-root/kernel/power/swsusp.c   |   18 +---
> >  4 files changed, 108 insertions(+), 15 deletions(-)
> > 
> > diff -puN kernel/power/snapshot.c~swsusp_save_pages kernel/power/snapshot.c
> > --- linux-2.6.17-rc1/kernel/power/snapshot.c~swsusp_save_pages	2006-04-10 09:14:35.000000000 +0800
> > +++ linux-2.6.17-rc1-root/kernel/power/snapshot.c	2006-04-11 08:03:21.000000000 +0800
> > @@ -39,6 +39,78 @@ static unsigned int nr_copy_pages;
> >  static unsigned int nr_meta_pages;
> >  static unsigned long *buffer;
> >  
> > +struct arch_saveable_page {
> > +	unsigned long pfn;
> > +	void *data;
> > +	struct arch_saveable_page *next;
> > +};
> > +static struct arch_saveable_page *arch_pages;
> > +
> > +int swsusp_add_arch_pages(unsigned long start, unsigned long end)
> > +{
> > +	struct arch_saveable_page *tmp;
> > +
> > +	while (start <= end) {
> > +		tmp = kzalloc(sizeof(struct arch_saveable_page), GFP_KERNEL);
> > +		if (!tmp)
> > +			return -ENOMEM;
> > +		tmp->pfn = start;
> > +		tmp->next = arch_pages;
> > +		start++;
> > +		arch_pages = tmp;
> > +	}
> > +	return 0;
> > +}
> > +
> > +static unsigned int count_arch_pages(void)
> > +{
> > +	unsigned int count = 0;
> > +	struct arch_saveable_page *tmp = arch_pages;
> > +	while (tmp) {
> > +		count++;
> > +		tmp = tmp->next;
> > +	}
> > +	return count;
> > +}
> > +
> > +static int save_arch_mem(void)
> > +{
> > +	void *kaddr;
> > +	struct arch_saveable_page *tmp = arch_pages;
> > +
> > +	pr_debug("swsusp: Saving arch specific memory");
> > +	while (tmp) {
> > +		tmp->data = (void *)get_zeroed_page(GFP_ATOMIC);
> > +		if (!tmp->data)
> > +			return -ENOMEM;
> > +		/* arch pages might haven't a 'struct page' */
> > +		kaddr = kmap_atomic_pfn(tmp->pfn, KM_PTE0);
> > +		memcpy(tmp->data, kaddr, PAGE_SIZE);
> > +		kunmap_atomic(kaddr, KM_PTE0);
> > +
> > +		tmp = tmp->next;
> > +	}
> > +	return 0;
> > +}
> > +
> > +static int restore_arch_mem(void)
> > +{
> > +	void *kaddr;
> > +	struct arch_saveable_page *tmp = arch_pages;
> > +
> > +	while (tmp) {
> > +		if (!tmp->data)
> > +			continue;
> > +		kaddr = kmap_atomic_pfn(tmp->pfn, KM_PTE0);
> > +		memcpy(kaddr, tmp->data, PAGE_SIZE);
> > +		kunmap_atomic(kaddr, KM_PTE0);
> > +		free_page((long)tmp->data);
> > +		tmp->data = NULL;
> > +		tmp = tmp->next;
> > +	}
> > +	return 0;
> > +}
> > +
> >  #ifdef CONFIG_HIGHMEM
> >  unsigned int count_highmem_pages(void)
> >  {
> > @@ -150,8 +222,35 @@ int restore_highmem(void)
> >  	}
> >  	return 0;
> >  }
> > +#else
> > +static unsigned int count_highmem_pages(void) {return 0;}
> > +static int save_highmem(void) {return 0;}
> > +static int restore_highmem(void) {return 0;}
> >  #endif
> >  
> > +unsigned int count_special_pages(void)
> > +{
> > +	return count_arch_pages() + count_highmem_pages();
> > +}
> > +
> > +int save_special_mem(void)
> > +{
> > +	int ret;
> > +	ret = save_arch_mem();
> > +	if (!ret)
> > +		ret = save_highmem();
> > +	return ret;
> > +}
> > +
> > +int restore_special_mem(void)
> > +{
> > +	int ret;
> > +	ret = restore_arch_mem();
> > +	if (!ret)
> > +		ret = restore_highmem();
> > +	return ret;
> > +}
> > +
> >  static int pfn_is_nosave(unsigned long pfn)
> >  {
> >  	unsigned long nosave_begin_pfn = __pa(&__nosave_begin) >> PAGE_SHIFT;
> > @@ -177,7 +276,6 @@ static int saveable(struct zone *zone, u
> >  		return 0;
> >  
> >  	page = pfn_to_page(pfn);
> > -	BUG_ON(PageReserved(page) && PageNosave(page));
> >  	if (PageNosave(page))
> >  		return 0;
> >  	if (PageReserved(page) && pfn_is_nosave(pfn))
> > diff -puN kernel/power/swsusp.c~swsusp_save_pages kernel/power/swsusp.c
> > --- linux-2.6.17-rc1/kernel/power/swsusp.c~swsusp_save_pages	2006-04-10 09:14:35.000000000 +0800
> > +++ linux-2.6.17-rc1-root/kernel/power/swsusp.c	2006-04-11 08:02:02.000000000 +0800
> > @@ -62,16 +62,6 @@ unsigned long image_size = 500 * 1024 * 
> >  
> >  int in_suspend __nosavedata = 0;
> >  
> > -#ifdef CONFIG_HIGHMEM
> > -unsigned int count_highmem_pages(void);
> > -int save_highmem(void);
> > -int restore_highmem(void);
> > -#else
> > -static int save_highmem(void) { return 0; }
> > -static int restore_highmem(void) { return 0; }
> > -static unsigned int count_highmem_pages(void) { return 0; }
> > -#endif
> > -
> >  /**
> >   *	The following functions are used for tracing the allocated
> >   *	swap pages, so that they can be freed in case of an error.
> > @@ -186,7 +176,7 @@ int swsusp_shrink_memory(void)
> >  
> >  	printk("Shrinking memory...  ");
> >  	do {
> > -		size = 2 * count_highmem_pages();
> > +		size = 2 * count_special_pages();
> >  		size += size / 50 + count_data_pages();
> >  		size += (size + PBES_PER_PAGE - 1) / PBES_PER_PAGE +
> >  			PAGES_FOR_IO;
> > @@ -228,7 +218,7 @@ int swsusp_suspend(void)
> >  		goto Enable_irqs;
> >  	}
> >  
> > -	if ((error = save_highmem())) {
> > +	if ((error = save_special_mem())) {
> >  		printk(KERN_ERR "swsusp: Not enough free pages for highmem\n");
> >  		goto Restore_highmem;
> >  	}
> > @@ -239,7 +229,7 @@ int swsusp_suspend(void)
> >  	/* Restore control flow magically appears here */
> >  	restore_processor_state();
> >  Restore_highmem:
> > -	restore_highmem();
> > +	restore_special_mem();
> >  	device_power_up();
> >  Enable_irqs:
> >  	local_irq_enable();
> > @@ -265,7 +255,7 @@ int swsusp_resume(void)
> >  	 */
> >  	swsusp_free();
> >  	restore_processor_state();
> > -	restore_highmem();
> > +	restore_special_mem();
> >  	touch_softlockup_watchdog();
> >  	device_power_up();
> >  	local_irq_enable();
> > diff -puN include/linux/suspend.h~swsusp_save_pages include/linux/suspend.h
> > --- linux-2.6.17-rc1/include/linux/suspend.h~swsusp_save_pages	2006-04-10 09:14:35.000000000 +0800
> > +++ linux-2.6.17-rc1-root/include/linux/suspend.h	2006-04-10 09:14:35.000000000 +0800
> > @@ -72,6 +72,7 @@ struct saved_context;
> >  void __save_processor_state(struct saved_context *ctxt);
> >  void __restore_processor_state(struct saved_context *ctxt);
> >  unsigned long get_safe_page(gfp_t gfp_mask);
> > +int swsusp_add_arch_pages(unsigned long start, unsigned long end);
> >  
> >  /*
> >   * XXX: We try to keep some more pages free so that I/O operations succeed
> > diff -puN kernel/power/power.h~swsusp_save_pages kernel/power/power.h
> > --- linux-2.6.17-rc1/kernel/power/power.h~swsusp_save_pages	2006-04-11 08:00:30.000000000 +0800
> > +++ linux-2.6.17-rc1-root/kernel/power/power.h	2006-04-11 08:02:03.000000000 +0800
> > @@ -105,6 +105,10 @@ extern struct bitmap_page *alloc_bitmap(
> >  extern unsigned long alloc_swap_page(int swap, struct bitmap_page *bitmap);
> >  extern void free_all_swap_pages(int swap, struct bitmap_page *bitmap);
> >  
> > +extern unsigned int count_special_pages(void);
> > +extern int save_special_mem(void);
> > +extern int restore_special_mem(void);
> > +
> >  extern int swsusp_check(void);
> >  extern int swsusp_shrink_memory(void);
> >  extern void swsusp_free(void);
> > _
> > 
> > 
> 
-- 
Shaohua Li <shaohua.li@xxxxxxxxx>

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