Add a misc device, "suspend_blocker", that allows user-space processesto block auto suspend. The device has ioctls to create a suspend_blocker,and to block and unblock suspend. To delete the suspend_blocker, closethe device.
Signed-off-by: Arve Hjønnevåg <arve@xxxxxxxxxxx>--- Documentation/power/suspend-blockers.txt | 17 ++++ include/linux/suspend_block_dev.h | 25 ++++++ kernel/power/Kconfig | 9 ++ kernel/power/Makefile | 1 + kernel/power/user_suspend_blocker.c | 125 ++++++++++++++++++++++++++++++ 5 files changed, 177 insertions(+), 0 deletions(-) create mode 100644 include/linux/suspend_block_dev.h create mode 100644 kernel/power/user_suspend_blocker.c
diff --git a/Documentation/power/suspend-blockers.txt b/Documentation/power/suspend-blockers.txtindex 5a33ed6..9d78d4e 100644--- a/Documentation/power/suspend-blockers.txt+++ b/Documentation/power/suspend-blockers.txt@@ -92,3 +92,20 @@ if (list_empty(&state->pending_work)) else suspend_block(&state->suspend_blocker); +User-space API+==============++To create a suspend_blocker from user-space, open the suspend_blocker device:+ fd = open("/dev/suspend_blocker", O_RDWR | O_CLOEXEC);+then call:+ ioctl(fd, SUSPEND_BLOCKER_IOCTL_INIT(strlen(name)), name);++To activate a suspend_blocker call:+ ioctl(fd, SUSPEND_BLOCKER_IOCTL_BLOCK);++To unblock call:+ ioctl(fd, SUSPEND_BLOCKER_IOCTL_UNBLOCK);++To destroy the suspend_blocker, close the device:+ close(fd);+diff --git a/include/linux/suspend_block_dev.h b/include/linux/suspend_block_dev.hnew file mode 100644index 0000000..a7c0bf9--- /dev/null+++ b/include/linux/suspend_block_dev.h@@ -0,0 +1,25 @@+/* include/linux/suspend_block_dev.h+ *+ * Copyright (C) 2009 Google, Inc.+ *+ * This software is licensed under the terms of the GNU General Public+ * License version 2, as published by the Free Software Foundation, and+ * may be copied, distributed, and modified under those terms.+ *+ * This program is distributed in the hope that it will be useful,+ * but WITHOUT ANY WARRANTY; without even the implied warranty of+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the+ * GNU General Public License for more details.+ *+ */++#ifndef _LINUX_SUSPEND_BLOCK_DEV_H+#define _LINUX_SUSPEND_BLOCK_DEV_H++#include <linux/ioctl.h>++#define SUSPEND_BLOCKER_IOCTL_INIT(len) _IOC(_IOC_WRITE, 's', 0, len)+#define SUSPEND_BLOCKER_IOCTL_BLOCK _IO('s', 1)+#define SUSPEND_BLOCKER_IOCTL_UNBLOCK _IO('s', 3)++#endifdiff --git a/kernel/power/Kconfig b/kernel/power/Kconfigindex a3587d3..84b423f 100644--- a/kernel/power/Kconfig+++ b/kernel/power/Kconfig@@ -126,6 +126,15 @@ config SUSPEND_BLOCKERS through /sys/power/request_state, the requested sleep state will be entered when no suspend blockers are active. +config USER_SUSPEND_BLOCKERS+ bool "Userspace suspend blockers"+ depends on SUSPEND_BLOCKERS+ default y+ ---help---+ User-space suspend block api. Creates a misc device with ioctls+ to create, block and unblock a suspend_blocker. The suspend_blocker+ will be deleted when the device is closed.+ config HIBERNATION bool "Hibernation (aka 'suspend to disk')" depends on PM && SWAP && ARCH_HIBERNATION_POSSIBLEdiff --git a/kernel/power/Makefile b/kernel/power/Makefileindex e8c7f85..24ade91 100644--- a/kernel/power/Makefile+++ b/kernel/power/Makefile@@ -7,6 +7,7 @@ obj-$(CONFIG_PM) += main.o obj-$(CONFIG_PM_SLEEP) += console.o obj-$(CONFIG_FREEZER) += process.o obj-$(CONFIG_SUSPEND_BLOCKERS) += suspend_blocker.o+obj-$(CONFIG_USER_SUSPEND_BLOCKERS) += user_suspend_blocker.o obj-$(CONFIG_HIBERNATION) += swsusp.o disk.o snapshot.o swap.o user.o obj-$(CONFIG_MAGIC_SYSRQ) += poweroff.odiff --git a/kernel/power/user_suspend_blocker.c b/kernel/power/user_suspend_blocker.cnew file mode 100644index 0000000..69b3ddb--- /dev/null+++ b/kernel/power/user_suspend_blocker.c@@ -0,0 +1,125 @@+/* kernel/power/user_suspend_block.c+ *+ * Copyright (C) 2009 Google, Inc.+ *+ * This software is licensed under the terms of the GNU General Public+ * License version 2, as published by the Free Software Foundation, and+ * may be copied, distributed, and modified under those terms.+ *+ * This program is distributed in the hope that it will be useful,+ * but WITHOUT ANY WARRANTY; without even the implied warranty of+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the+ * GNU General Public License for more details.+ *+ */++#include <linux/fs.h>+#include <linux/miscdevice.h>+#include <linux/module.h>+#include <linux/uaccess.h>+#include <linux/suspend_blocker.h>+#include <linux/suspend_block_dev.h>++enum {+ DEBUG_FAILURE = BIT(0),+};+static int debug_mask = DEBUG_FAILURE;+module_param_named(debug_mask, debug_mask, int, S_IRUGO | S_IWUSR | S_IWGRP);++static DEFINE_MUTEX(ioctl_lock);++struct user_suspend_blocker {+ struct suspend_blocker blocker;+ char name[0];+};++static int create_user_suspend_blocker(struct file *file, void __user *name,+ size_t name_len)+{+ struct user_suspend_blocker *bl;+ if (file->private_data)+ return -EBUSY;+ bl = kzalloc(sizeof(*bl) + name_len + 1, GFP_KERNEL);+ if (!bl)+ return -ENOMEM;+ if (copy_from_user(bl->name, name, name_len))+ goto err_fault;+ suspend_blocker_init(&bl->blocker, bl->name);+ file->private_data = bl;+ return 0;++err_fault:+ kfree(bl);+ return -EFAULT;+}++static long user_suspend_blocker_ioctl(struct file *file, unsigned int cmd,+ unsigned long _arg)+{+ void __user *arg = (void __user *)_arg;+ struct user_suspend_blocker *bl;+ long ret;++ mutex_lock(&ioctl_lock);+ if ((cmd & ~IOCSIZE_MASK) == SUSPEND_BLOCKER_IOCTL_INIT(0)) {+ ret = create_user_suspend_blocker(file, arg, _IOC_SIZE(cmd));+ goto done;+ }+ bl = file->private_data;+ if (!bl) {+ ret = -ENOENT;+ goto done;+ }+ switch (cmd) {+ case SUSPEND_BLOCKER_IOCTL_BLOCK:+ suspend_block(&bl->blocker);+ ret = 0;+ break;+ case SUSPEND_BLOCKER_IOCTL_UNBLOCK:+ suspend_unblock(&bl->blocker);+ ret = 0;+ break;+ default:+ ret = -ENOTSUPP;+ }+done:+ if (ret && debug_mask & DEBUG_FAILURE)+ pr_err("user_suspend_blocker_ioctl: cmd %x failed, %ld\n",+ cmd, ret);+ mutex_unlock(&ioctl_lock);+ return ret;+}++static int user_suspend_blocker_release(struct inode *inode, struct file *file)+{+ struct user_suspend_blocker *bl = file->private_data;+ if (!bl)+ return 0;+ suspend_blocker_destroy(&bl->blocker);+ kfree(bl);+ return 0;+}++const struct file_operations user_suspend_blocker_fops = {+ .release = user_suspend_blocker_release,+ .unlocked_ioctl = user_suspend_blocker_ioctl,+};++struct miscdevice user_suspend_blocker_device = {+ .minor = MISC_DYNAMIC_MINOR,+ .name = "suspend_blocker",+ .fops = &user_suspend_blocker_fops,+};++static int __init user_suspend_blocker_init(void)+{+ return misc_register(&user_suspend_blocker_device);+}++static void __exit user_suspend_blocker_exit(void)+{+ misc_deregister(&user_suspend_blocker_device);+}++module_init(user_suspend_blocker_init);+module_exit(user_suspend_blocker_exit);-- 1.6.1
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