4 files changed, 321 insertions, 5 deletions

diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index bb91a0615303..8d0af3d37a4b 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -5,7 +5,7 @@ endif
 
 obj-y                           := main.o process.o console.o
 obj-$(CONFIG_PM_LEGACY)         += pm.o
-obj-$(CONFIG_SOFTWARE_SUSPEND)  += swsusp.o disk.o snapshot.o swap.o
+obj-$(CONFIG_SOFTWARE_SUSPEND)  += swsusp.o disk.o snapshot.o swap.o user.o
 
 obj-$(CONFIG_SUSPEND_SMP)       += smp.o
 
diff --git a/kernel/power/power.h b/kernel/power/power.h
index 5d1abffbb9ce..42c431c8bdde 100644
--- a/kernel/power/power.h
+++ b/kernel/power/power.h
@@ -8,6 +8,7 @@ struct swsusp_info {
         int                     cpus;
         unsigned long           image_pages;
         unsigned long           pages;
+        unsigned long           size;
 } __attribute__((aligned(PAGE_SIZE)));
 
 
@@ -65,6 +66,19 @@ extern int snapshot_read_next(struct snapshot_handle *handle, size_t count);
 extern int snapshot_write_next(struct snapshot_handle *handle, size_t count);
 int snapshot_image_loaded(struct snapshot_handle *handle);
 
+#define SNAPSHOT_IOC_MAGIC      '3'
+#define SNAPSHOT_FREEZE                 _IO(SNAPSHOT_IOC_MAGIC, 1)
+#define SNAPSHOT_UNFREEZE               _IO(SNAPSHOT_IOC_MAGIC, 2)
+#define SNAPSHOT_ATOMIC_SNAPSHOT        _IOW(SNAPSHOT_IOC_MAGIC, 3, void *)
+#define SNAPSHOT_ATOMIC_RESTORE         _IO(SNAPSHOT_IOC_MAGIC, 4)
+#define SNAPSHOT_FREE                   _IO(SNAPSHOT_IOC_MAGIC, 5)
+#define SNAPSHOT_SET_IMAGE_SIZE         _IOW(SNAPSHOT_IOC_MAGIC, 6, unsigned long)
+#define SNAPSHOT_AVAIL_SWAP             _IOR(SNAPSHOT_IOC_MAGIC, 7, void *)
+#define SNAPSHOT_GET_SWAP_PAGE          _IOR(SNAPSHOT_IOC_MAGIC, 8, void *)
+#define SNAPSHOT_FREE_SWAP_PAGES        _IO(SNAPSHOT_IOC_MAGIC, 9)
+#define SNAPSHOT_SET_SWAP_FILE          _IOW(SNAPSHOT_IOC_MAGIC, 10, unsigned int)
+#define SNAPSHOT_IOC_MAXNR      10
+
 /**
  *      The bitmap is used for tracing allocated swap pages
  *
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index cc349437fb72..0036955357e0 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -37,6 +37,7 @@
 struct pbe *pagedir_nosave;
 static unsigned int nr_copy_pages;
 static unsigned int nr_meta_pages;
+static unsigned long *buffer;
 
 #ifdef CONFIG_HIGHMEM
 unsigned int count_highmem_pages(void)
@@ -389,7 +390,7 @@ struct pbe *alloc_pagedir(unsigned int nr_pages, gfp_t gfp_mask, int safe_needed
                 free_pagedir(pblist);
                 pblist = NULL;
         } else
-                create_pbe_list(pblist, nr_pages);
+                create_pbe_list(pblist, nr_pages);
         return pblist;
 }
 
@@ -418,6 +419,7 @@ void swsusp_free(void)
         nr_copy_pages = 0;
         nr_meta_pages = 0;
         pagedir_nosave = NULL;
+        buffer = NULL;
 }
 
 
@@ -523,6 +525,8 @@ static void init_header(struct swsusp_info *info)
         info->cpus = num_online_cpus();
         info->image_pages = nr_copy_pages;
         info->pages = nr_copy_pages + nr_meta_pages + 1;
+        info->size = info->pages;
+        info->size <<= PAGE_SHIFT;
 }
 
 /**
@@ -568,8 +572,6 @@ static inline struct pbe *pack_orig_addresses(unsigned long *buf, struct pbe *pb
 
 int snapshot_read_next(struct snapshot_handle *handle, size_t count)
 {
-        static unsigned long *buffer;
-
         if (handle->page > nr_meta_pages + nr_copy_pages)
                 return 0;
         if (!buffer) {
@@ -774,7 +776,6 @@ static int create_image(struct snapshot_handle *handle)
 
 int snapshot_write_next(struct snapshot_handle *handle, size_t count)
 {
-        static unsigned long *buffer;
         int error = 0;
 
         if (handle->prev && handle->page > nr_meta_pages + nr_copy_pages)
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 <rjw@sisk.pl>
+ *
+ * This file is released under the GPLv2.
+ *
+ */
+
+#include <linux/suspend.h>
+#include <linux/syscalls.h>
+#include <linux/string.h>
+#include <linux/device.h>
+#include <linux/miscdevice.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/pm.h>
+#include <linux/fs.h>
+
+#include <asm/uaccess.h>
+
+#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);