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e73a780272
Make sure that when the WDIOF_MAGICCLOSE flag is set we also support the magic-close feature... Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
227 lines
5.1 KiB
C
227 lines
5.1 KiB
C
/*
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* SBC EPX C3 0.1 A Hardware Watchdog Device for the Winsystems EPX-C3
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* single board computer
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*
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* (c) Copyright 2006 Calin A. Culianu <calin@ajvar.org>, All Rights
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* Reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*
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* based on softdog.c by Alan Cox <alan@lxorguk.ukuu.org.uk>
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*/
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/miscdevice.h>
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#include <linux/watchdog.h>
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#include <linux/notifier.h>
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#include <linux/reboot.h>
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#include <linux/init.h>
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#include <linux/ioport.h>
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#include <linux/uaccess.h>
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#include <linux/io.h>
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#define PFX "epx_c3: "
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static int epx_c3_alive;
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#define WATCHDOG_TIMEOUT 1 /* 1 sec default timeout */
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static int nowayout = WATCHDOG_NOWAYOUT;
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module_param(nowayout, int, 0);
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MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default="
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__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
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#define EPXC3_WATCHDOG_CTL_REG 0x1ee /* write 1 to enable, 0 to disable */
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#define EPXC3_WATCHDOG_PET_REG 0x1ef /* write anything to pet once enabled */
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static void epx_c3_start(void)
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{
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outb(1, EPXC3_WATCHDOG_CTL_REG);
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}
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static void epx_c3_stop(void)
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{
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outb(0, EPXC3_WATCHDOG_CTL_REG);
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printk(KERN_INFO PFX "Stopped watchdog timer.\n");
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}
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static void epx_c3_pet(void)
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{
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outb(1, EPXC3_WATCHDOG_PET_REG);
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}
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/*
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* Allow only one person to hold it open
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*/
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static int epx_c3_open(struct inode *inode, struct file *file)
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{
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if (epx_c3_alive)
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return -EBUSY;
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if (nowayout)
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__module_get(THIS_MODULE);
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/* Activate timer */
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epx_c3_start();
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epx_c3_pet();
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epx_c3_alive = 1;
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printk(KERN_INFO "Started watchdog timer.\n");
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return nonseekable_open(inode, file);
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}
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static int epx_c3_release(struct inode *inode, struct file *file)
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{
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/* Shut off the timer.
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* Lock it in if it's a module and we defined ...NOWAYOUT */
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if (!nowayout)
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epx_c3_stop(); /* Turn the WDT off */
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epx_c3_alive = 0;
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return 0;
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}
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static ssize_t epx_c3_write(struct file *file, const char __user *data,
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size_t len, loff_t *ppos)
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{
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/* Refresh the timer. */
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if (len)
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epx_c3_pet();
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return len;
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}
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static long epx_c3_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int options, retval = -EINVAL;
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int __user *argp = (void __user *)arg;
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static const struct watchdog_info ident = {
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.options = WDIOF_KEEPALIVEPING,
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.firmware_version = 0,
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.identity = "Winsystems EPX-C3 H/W Watchdog",
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};
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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if (copy_to_user(argp, &ident, sizeof(ident)))
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return -EFAULT;
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return 0;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, argp);
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case WDIOC_SETOPTIONS:
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if (get_user(options, argp))
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return -EFAULT;
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if (options & WDIOS_DISABLECARD) {
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epx_c3_stop();
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retval = 0;
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}
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if (options & WDIOS_ENABLECARD) {
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epx_c3_start();
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retval = 0;
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}
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return retval;
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case WDIOC_KEEPALIVE:
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epx_c3_pet();
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return 0;
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case WDIOC_GETTIMEOUT:
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return put_user(WATCHDOG_TIMEOUT, argp);
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default:
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return -ENOTTY;
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}
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}
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static int epx_c3_notify_sys(struct notifier_block *this, unsigned long code,
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void *unused)
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{
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if (code == SYS_DOWN || code == SYS_HALT)
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epx_c3_stop(); /* Turn the WDT off */
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return NOTIFY_DONE;
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}
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static const struct file_operations epx_c3_fops = {
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.owner = THIS_MODULE,
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.llseek = no_llseek,
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.write = epx_c3_write,
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.unlocked_ioctl = epx_c3_ioctl,
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.open = epx_c3_open,
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.release = epx_c3_release,
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};
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static struct miscdevice epx_c3_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &epx_c3_fops,
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};
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static struct notifier_block epx_c3_notifier = {
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.notifier_call = epx_c3_notify_sys,
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};
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static const char banner[] __initdata = KERN_INFO PFX
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"Hardware Watchdog Timer for Winsystems EPX-C3 SBC: 0.1\n";
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static int __init watchdog_init(void)
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{
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int ret;
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if (!request_region(EPXC3_WATCHDOG_CTL_REG, 2, "epxc3_watchdog"))
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return -EBUSY;
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ret = register_reboot_notifier(&epx_c3_notifier);
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if (ret) {
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printk(KERN_ERR PFX "cannot register reboot notifier "
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"(err=%d)\n", ret);
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goto out;
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}
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ret = misc_register(&epx_c3_miscdev);
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if (ret) {
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printk(KERN_ERR PFX "cannot register miscdev on minor=%d "
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"(err=%d)\n", WATCHDOG_MINOR, ret);
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unregister_reboot_notifier(&epx_c3_notifier);
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goto out;
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}
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printk(banner);
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return 0;
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out:
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release_region(EPXC3_WATCHDOG_CTL_REG, 2);
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return ret;
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}
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static void __exit watchdog_exit(void)
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{
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misc_deregister(&epx_c3_miscdev);
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unregister_reboot_notifier(&epx_c3_notifier);
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release_region(EPXC3_WATCHDOG_CTL_REG, 2);
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}
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module_init(watchdog_init);
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module_exit(watchdog_exit);
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MODULE_AUTHOR("Calin A. Culianu <calin@ajvar.org>");
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MODULE_DESCRIPTION("Hardware Watchdog Device for Winsystems EPX-C3 SBC. "
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"Note that there is no way to probe for this device -- "
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"so only use it if you are *sure* you are runnning on this specific "
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"SBC system from Winsystems! It writes to IO ports 0x1ee and 0x1ef!");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS_MISCDEV(WATCHDOG_MINOR);
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