Re: [PATCH]: In kernel hibernation, suspend to both: draft

[Rafael J. Wysocki]

Hi,

On Monday, May 07, 2012, Bojan Smojver wrote:
> Hi Rafael,
> 
> Was just playing with it and this is what I came up with. This is just a
> rough draft (I didn't even think of memory leaks and such here, to be
> honest). Let me know what you think.

Looks reasonable at first sight.

Thanks,
Rafael


> ------------------------------
> diff --git a/Documentation/power/swsusp.txt b/Documentation/power/swsusp.txt
> index ac190cf..92341b8 100644
> --- a/Documentation/power/swsusp.txt
> +++ b/Documentation/power/swsusp.txt
> @@ -33,6 +33,11 @@ echo shutdown > /sys/power/disk; echo disk > /sys/power/state
>  
>  echo platform > /sys/power/disk; echo disk > /sys/power/state
>  
> +. If you would like to write hibernation image to swap and then suspend
> +to RAM (provided your platform supports it), you can try
> +
> +echo suspend > /sys/power/disk; echo disk > /sys/power/state
> +
>  . If you have SATA disks, you'll need recent kernels with SATA suspend
>  support. For suspend and resume to work, make sure your disk drivers
>  are built into kernel -- not modules. [There's way to make
> diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c
> index e09dfbf..3b5726f 100644
> --- a/kernel/power/hibernate.c
> +++ b/kernel/power/hibernate.c
> @@ -5,6 +5,7 @@
>   * Copyright (c) 2003 Open Source Development Lab
>   * Copyright (c) 2004 Pavel Machek <pavel@xxxxxx>
>   * Copyright (c) 2009 Rafael J. Wysocki, Novell Inc.
> + * Copyright (C) 2012 Bojan Smojver <bojan@xxxxxxxxxxxxx>
>   *
>   * This file is released under the GPLv2.
>   */
> @@ -44,6 +45,9 @@ enum {
>  	HIBERNATION_PLATFORM,
>  	HIBERNATION_SHUTDOWN,
>  	HIBERNATION_REBOOT,
> +#ifdef CONFIG_SUSPEND
> +	HIBERNATION_SUSPEND,
> +#endif
>  	/* keep last */
>  	__HIBERNATION_AFTER_LAST
>  };
> @@ -572,6 +576,10 @@ int hibernation_platform_enter(void)
>   */
>  static void power_down(void)
>  {
> +#ifdef CONFIG_SUSPEND
> +	int error;
> +#endif
> +
>  	switch (hibernation_mode) {
>  	case HIBERNATION_REBOOT:
>  		kernel_restart(NULL);
> @@ -581,6 +589,25 @@ static void power_down(void)
>  	case HIBERNATION_SHUTDOWN:
>  		kernel_power_off();
>  		break;
> +#ifdef CONFIG_SUSPEND
> +	case HIBERNATION_SUSPEND:
> +		error = suspend_devices_and_enter(PM_SUSPEND_MEM);
> +		if (error) {
> +			if (hibernation_ops)
> +				hibernation_mode = HIBERNATION_PLATFORM;
> +			else
> +				hibernation_mode = HIBERNATION_SHUTDOWN;
> +			power_down();
> +		}
> +		/*
> +		 * Restore swap signature.
> +		 */
> +		error = swsusp_unmark();
> +		if (error)
> +			printk(KERN_ERR "PM: Swap will be unusable! "
> +			                "Try swapon -a.\n");
> +		return;
> +#endif
>  	}
>  	kernel_halt();
>  	/*
> @@ -814,6 +841,9 @@ static const char * const hibernation_modes[] = {
>  	[HIBERNATION_PLATFORM]	= "platform",
>  	[HIBERNATION_SHUTDOWN]	= "shutdown",
>  	[HIBERNATION_REBOOT]	= "reboot",
> +#ifdef CONFIG_SUSPEND
> +	[HIBERNATION_SUSPEND]	= "suspend",
> +#endif
>  };
>  
>  /*
> @@ -854,6 +884,9 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr,
>  		switch (i) {
>  		case HIBERNATION_SHUTDOWN:
>  		case HIBERNATION_REBOOT:
> +#ifdef CONFIG_SUSPEND
> +		case HIBERNATION_SUSPEND:
> +#endif
>  			break;
>  		case HIBERNATION_PLATFORM:
>  			if (hibernation_ops)
> @@ -894,6 +927,9 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr,
>  		switch (mode) {
>  		case HIBERNATION_SHUTDOWN:
>  		case HIBERNATION_REBOOT:
> +#ifdef CONFIG_SUSPEND
> +		case HIBERNATION_SUSPEND:
> +#endif
>  			hibernation_mode = mode;
>  			break;
>  		case HIBERNATION_PLATFORM:
> diff --git a/kernel/power/power.h b/kernel/power/power.h
> index 98f3622..07b4a68 100644
> --- a/kernel/power/power.h
> +++ b/kernel/power/power.h
> @@ -156,6 +156,9 @@ extern void swsusp_free(void);
>  extern int swsusp_read(unsigned int *flags_p);
>  extern int swsusp_write(unsigned int flags);
>  extern void swsusp_close(fmode_t);
> +#ifdef CONFIG_SUSPEND
> +extern int swsusp_unmark(void);
> +#endif
>  
>  /* kernel/power/block_io.c */
>  extern struct block_device *hib_resume_bdev;
> diff --git a/kernel/power/swap.c b/kernel/power/swap.c
> index eef311a..1027da8 100644
> --- a/kernel/power/swap.c
> +++ b/kernel/power/swap.c
> @@ -1456,6 +1456,34 @@ void swsusp_close(fmode_t mode)
>  	blkdev_put(hib_resume_bdev, mode);
>  }
>  
> +/**
> + *      swsusp_unmark - Unmark swsusp signature in the resume device
> + */
> +
> +#ifdef CONFIG_SUSPEND
> +int swsusp_unmark(void)
> +{
> +	int error;
> +
> +	hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
> +	if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
> +		memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
> +		error = hib_bio_write_page(swsusp_resume_block,
> +					swsusp_header, NULL);
> +	} else {
> +		printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
> +		error = -ENODEV;
> +	}
> +
> +	/*
> +	 * We just returned from suspend, we don't need the image any more.
> +	 */
> +	free_all_swap_pages(root_swap);
> +
> +	return error;
> +}
> +#endif
> +
>  static int swsusp_header_init(void)
>  {
>  	swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
> ------------------------------
> 
> 

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/