From 6e1819d615f24ce0726a7d0bd3dd0152d7b21654 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 23 Mar 2006 03:00:03 -0800 Subject: [PATCH] swsusp: userland interface MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This patch introduces a user space interface for swsusp. The interface is based on a special character device, called the snapshot device, that allows user space processes to perform suspend and resume-related operations with the help of some ioctls and the read()/write() functions.  Additionally it allows these processes to allocate free swap pages from a selected swap partition, called the resume partition, so that they know which sectors of the resume partition are available to them. The interface uses the same low-level system memory snapshot-handling functions that are used by the built-it swap-writing/reading code of swsusp. The interface documentation is included in the patch. The patch assumes that the major and minor numbers of the snapshot device will be 10 (ie. misc device) and 231, the registration of which has already been requested. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/user.c | 301 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 301 insertions(+) create mode 100644 kernel/power/user.c (limited to 'kernel/power/user.c') diff --git a/kernel/power/user.c b/kernel/power/user.c new file mode 100644 index 000000000000..8cabc405ca10 --- /dev/null +++ b/kernel/power/user.c @@ -0,0 +1,301 @@ +/* + * linux/kernel/power/user.c + * + * This file provides the user space interface for software suspend/resume. + * + * Copyright (C) 2006 Rafael J. Wysocki + * + * This file is released under the GPLv2. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +#include "power.h" + +#define SNAPSHOT_MINOR 231 + +static struct snapshot_data { + struct snapshot_handle handle; + int swap; + struct bitmap_page *bitmap; + int mode; + char frozen; + char ready; +} snapshot_state; + +static atomic_t device_available = ATOMIC_INIT(1); + +static int snapshot_open(struct inode *inode, struct file *filp) +{ + struct snapshot_data *data; + + if (!atomic_add_unless(&device_available, -1, 0)) + return -EBUSY; + + if ((filp->f_flags & O_ACCMODE) == O_RDWR) + return -ENOSYS; + + nonseekable_open(inode, filp); + data = &snapshot_state; + filp->private_data = data; + memset(&data->handle, 0, sizeof(struct snapshot_handle)); + if ((filp->f_flags & O_ACCMODE) == O_RDONLY) { + data->swap = swsusp_resume_device ? swap_type_of(swsusp_resume_device) : -1; + data->mode = O_RDONLY; + } else { + data->swap = -1; + data->mode = O_WRONLY; + } + data->bitmap = NULL; + data->frozen = 0; + data->ready = 0; + + return 0; +} + +static int snapshot_release(struct inode *inode, struct file *filp) +{ + struct snapshot_data *data; + + swsusp_free(); + data = filp->private_data; + free_all_swap_pages(data->swap, data->bitmap); + free_bitmap(data->bitmap); + if (data->frozen) { + down(&pm_sem); + thaw_processes(); + enable_nonboot_cpus(); + up(&pm_sem); + } + atomic_inc(&device_available); + return 0; +} + +static ssize_t snapshot_read(struct file *filp, char __user *buf, + size_t count, loff_t *offp) +{ + struct snapshot_data *data; + ssize_t res; + + data = filp->private_data; + res = snapshot_read_next(&data->handle, count); + if (res > 0) { + if (copy_to_user(buf, data_of(data->handle), res)) + res = -EFAULT; + else + *offp = data->handle.offset; + } + return res; +} + +static ssize_t snapshot_write(struct file *filp, const char __user *buf, + size_t count, loff_t *offp) +{ + struct snapshot_data *data; + ssize_t res; + + data = filp->private_data; + res = snapshot_write_next(&data->handle, count); + if (res > 0) { + if (copy_from_user(data_of(data->handle), buf, res)) + res = -EFAULT; + else + *offp = data->handle.offset; + } + return res; +} + +static int snapshot_ioctl(struct inode *inode, struct file *filp, + unsigned int cmd, unsigned long arg) +{ + int error = 0; + struct snapshot_data *data; + loff_t offset, avail; + + if (_IOC_TYPE(cmd) != SNAPSHOT_IOC_MAGIC) + return -ENOTTY; + if (_IOC_NR(cmd) > SNAPSHOT_IOC_MAXNR) + return -ENOTTY; + if (!capable(CAP_SYS_ADMIN)) + return -EPERM; + + data = filp->private_data; + + switch (cmd) { + + case SNAPSHOT_FREEZE: + if (data->frozen) + break; + sys_sync(); + down(&pm_sem); + pm_prepare_console(); + disable_nonboot_cpus(); + if (freeze_processes()) { + thaw_processes(); + enable_nonboot_cpus(); + pm_restore_console(); + error = -EBUSY; + } + up(&pm_sem); + if (!error) + data->frozen = 1; + break; + + case SNAPSHOT_UNFREEZE: + if (!data->frozen) + break; + down(&pm_sem); + thaw_processes(); + enable_nonboot_cpus(); + pm_restore_console(); + up(&pm_sem); + data->frozen = 0; + break; + + case SNAPSHOT_ATOMIC_SNAPSHOT: + if (data->mode != O_RDONLY || !data->frozen || data->ready) { + error = -EPERM; + break; + } + down(&pm_sem); + /* Free memory before shutting down devices. */ + error = swsusp_shrink_memory(); + if (!error) { + error = device_suspend(PMSG_FREEZE); + if (!error) { + in_suspend = 1; + error = swsusp_suspend(); + device_resume(); + } + } + up(&pm_sem); + if (!error) + error = put_user(in_suspend, (unsigned int __user *)arg); + if (!error) + data->ready = 1; + break; + + case SNAPSHOT_ATOMIC_RESTORE: + if (data->mode != O_WRONLY || !data->frozen || + !snapshot_image_loaded(&data->handle)) { + error = -EPERM; + break; + } + down(&pm_sem); + pm_prepare_console(); + error = device_suspend(PMSG_FREEZE); + if (!error) { + error = swsusp_resume(); + device_resume(); + } + pm_restore_console(); + up(&pm_sem); + break; + + case SNAPSHOT_FREE: + swsusp_free(); + memset(&data->handle, 0, sizeof(struct snapshot_handle)); + data->ready = 0; + break; + + case SNAPSHOT_SET_IMAGE_SIZE: + image_size = arg; + break; + + case SNAPSHOT_AVAIL_SWAP: + avail = count_swap_pages(data->swap, 1); + avail <<= PAGE_SHIFT; + error = put_user(avail, (loff_t __user *)arg); + break; + + case SNAPSHOT_GET_SWAP_PAGE: + if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { + error = -ENODEV; + break; + } + if (!data->bitmap) { + data->bitmap = alloc_bitmap(count_swap_pages(data->swap, 0)); + if (!data->bitmap) { + error = -ENOMEM; + break; + } + } + offset = alloc_swap_page(data->swap, data->bitmap); + if (offset) { + offset <<= PAGE_SHIFT; + error = put_user(offset, (loff_t __user *)arg); + } else { + error = -ENOSPC; + } + break; + + case SNAPSHOT_FREE_SWAP_PAGES: + if (data->swap < 0 || data->swap >= MAX_SWAPFILES) { + error = -ENODEV; + break; + } + free_all_swap_pages(data->swap, data->bitmap); + free_bitmap(data->bitmap); + data->bitmap = NULL; + break; + + case SNAPSHOT_SET_SWAP_FILE: + if (!data->bitmap) { + /* + * User space encodes device types as two-byte values, + * so we need to recode them + */ + if (old_decode_dev(arg)) { + data->swap = swap_type_of(old_decode_dev(arg)); + if (data->swap < 0) + error = -ENODEV; + } else { + data->swap = -1; + error = -EINVAL; + } + } else { + error = -EPERM; + } + break; + + default: + error = -ENOTTY; + + } + + return error; +} + +static struct file_operations snapshot_fops = { + .open = snapshot_open, + .release = snapshot_release, + .read = snapshot_read, + .write = snapshot_write, + .llseek = no_llseek, + .ioctl = snapshot_ioctl, +}; + +static struct miscdevice snapshot_device = { + .minor = SNAPSHOT_MINOR, + .name = "snapshot", + .fops = &snapshot_fops, +}; + +static int __init snapshot_device_init(void) +{ + return misc_register(&snapshot_device); +}; + +device_initcall(snapshot_device_init); -- cgit v1.2.3 From 02aaeb9b952f30b1ad6284d5d45be02030f679db Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 23 Mar 2006 03:00:04 -0800 Subject: [PATCH] swsusp: freeze user space processes first Allow swsusp to freeze processes successfully under heavy load by freezing userspace processes before kernel threads. [Thanks to Nigel Cunningham for suggesting the way to go.] Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/user.c | 1 - 1 file changed, 1 deletion(-) (limited to 'kernel/power/user.c') diff --git a/kernel/power/user.c b/kernel/power/user.c index 8cabc405ca10..a97406b86ef3 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -138,7 +138,6 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, case SNAPSHOT_FREEZE: if (data->frozen) break; - sys_sync(); down(&pm_sem); pm_prepare_console(); disable_nonboot_cpus(); -- cgit v1.2.3 From 94c188d32996beac00426740974310e32f162c14 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 23 Mar 2006 03:00:08 -0800 Subject: [PATCH] swsusp: let userland tools switch console on suspend Remove the console-switching code from the suspend part of the swsusp userland interface and let the userland tools switch the console. Signed-off-by: Rafael J. Wysocki Acked-by: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/user.c | 3 --- 1 file changed, 3 deletions(-) (limited to 'kernel/power/user.c') diff --git a/kernel/power/user.c b/kernel/power/user.c index a97406b86ef3..bbd4842104aa 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -139,12 +139,10 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, if (data->frozen) break; down(&pm_sem); - pm_prepare_console(); disable_nonboot_cpus(); if (freeze_processes()) { thaw_processes(); enable_nonboot_cpus(); - pm_restore_console(); error = -EBUSY; } up(&pm_sem); @@ -158,7 +156,6 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, down(&pm_sem); thaw_processes(); enable_nonboot_cpus(); - pm_restore_console(); up(&pm_sem); data->frozen = 0; break; -- cgit v1.2.3 From 9b238205ba5d79a8a242d7a5ddb82b89e4dc4e48 Mon Sep 17 00:00:00 2001 From: Luca Tettamanti Date: Thu, 23 Mar 2006 03:00:09 -0800 Subject: [PATCH] swsusp: add s2ram ioctl to userland interface Add the SNAPSHOT_S2RAM ioctl to the snapshot device. This ioctl allows a userland application to make the system (previously frozen with the SNAPSHOT_FREE ioctl) enter the S3 state without freezing processes and disabling nonboot CPUs for the second time. This will allow us to implement the suspend-to-disk-and-RAM (STDR) functionality in the userland suspend tools. Signed-off-by: Luca Tettamanti Signed-off-by: Rafael J. Wysocki Cc: Pavel Machek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/power/user.c | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) (limited to 'kernel/power/user.c') diff --git a/kernel/power/user.c b/kernel/power/user.c index bbd4842104aa..3f1539fbe48a 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -266,6 +266,42 @@ static int snapshot_ioctl(struct inode *inode, struct file *filp, } break; + case SNAPSHOT_S2RAM: + if (!data->frozen) { + error = -EPERM; + break; + } + + if (down_trylock(&pm_sem)) { + error = -EBUSY; + break; + } + + if (pm_ops->prepare) { + error = pm_ops->prepare(PM_SUSPEND_MEM); + if (error) + goto OutS3; + } + + /* Put devices to sleep */ + error = device_suspend(PMSG_SUSPEND); + if (error) { + printk(KERN_ERR "Failed to suspend some devices.\n"); + } else { + /* Enter S3, system is already frozen */ + suspend_enter(PM_SUSPEND_MEM); + + /* Wake up devices */ + device_resume(); + } + + if (pm_ops->finish) + pm_ops->finish(PM_SUSPEND_MEM); + +OutS3: + up(&pm_sem); + break; + default: error = -ENOTTY; -- cgit v1.2.3