linux/drivers/watchdog/intel_scu_watchdog.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Intel_SCU 0.2: An Intel SCU IOH Based Watchdog Device
* for Intel part #(s):
* - AF82MP20 PCH
*
* Copyright (C) 2009-2010 Intel Corporation. All rights reserved.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/miscdevice.h>
#include <linux/watchdog.h>
#include <linux/fs.h>
#include <linux/notifier.h>
#include <linux/reboot.h>
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/signal.h>
#include <linux/sfi.h>
#include <asm/irq.h>
#include <linux/atomic.h>
#include <asm/intel_scu_ipc.h>
#include <asm/apb_timer.h>
#include <asm/intel-mid.h>
#include "intel_scu_watchdog.h"
/* Bounds number of times we will retry loading time count */
/* This retry is a work around for a silicon bug. */
#define MAX_RETRY 16
#define IPC_SET_WATCHDOG_TIMER 0xF8
static int timer_margin = DEFAULT_SOFT_TO_HARD_MARGIN;
module_param(timer_margin, int, 0);
MODULE_PARM_DESC(timer_margin,
"Watchdog timer margin"
"Time between interrupt and resetting the system"
"The range is from 1 to 160"
"This is the time for all keep alives to arrive");
static int timer_set = DEFAULT_TIME;
module_param(timer_set, int, 0);
MODULE_PARM_DESC(timer_set,
"Default Watchdog timer setting"
"Complete cycle time"
"The range is from 1 to 170"
"This is the time for all keep alives to arrive");
/* After watchdog device is closed, check force_boot. If:
* force_boot == 0, then force boot on next watchdog interrupt after close,
* force_boot == 1, then force boot immediately when device is closed.
*/
static int force_boot;
module_param(force_boot, int, 0);
MODULE_PARM_DESC(force_boot,
"A value of 1 means that the driver will reboot"
"the system immediately if the /dev/watchdog device is closed"
"A value of 0 means that when /dev/watchdog device is closed"
"the watchdog timer will be refreshed for one more interval"
"of length: timer_set. At the end of this interval, the"
"watchdog timer will reset the system."
);
/* there is only one device in the system now; this can be made into
* an array in the future if we have more than one device */
static struct intel_scu_watchdog_dev watchdog_device;
/* Forces restart, if force_reboot is set */
static void watchdog_fire(void)
{
if (force_boot) {
pr_crit("Initiating system reboot\n");
emergency_restart();
pr_crit("Reboot didn't ?????\n");
}
else {
pr_crit("Immediate Reboot Disabled\n");
pr_crit("System will reset when watchdog timer times out!\n");
}
}
static int check_timer_margin(int new_margin)
{
if ((new_margin < MIN_TIME_CYCLE) ||
(new_margin > MAX_TIME - timer_set)) {
pr_debug("value of new_margin %d is out of the range %d to %d\n",
new_margin, MIN_TIME_CYCLE, MAX_TIME - timer_set);
return -EINVAL;
}
return 0;
}
/*
* IPC operations
*/
static int watchdog_set_ipc(int soft_threshold, int threshold)
{
u32 *ipc_wbuf;
u8 cbuf[16] = { '\0' };
int ipc_ret = 0;
ipc_wbuf = (u32 *)&cbuf;
ipc_wbuf[0] = soft_threshold;
ipc_wbuf[1] = threshold;
ipc_ret = intel_scu_ipc_command(
IPC_SET_WATCHDOG_TIMER,
0,
ipc_wbuf,
2,
NULL,
0);
if (ipc_ret != 0)
pr_err("Error setting SCU watchdog timer: %x\n", ipc_ret);
return ipc_ret;
};
/*
* Intel_SCU operations
*/
/* timer interrupt handler */
static irqreturn_t watchdog_timer_interrupt(int irq, void *dev_id)
{
int int_status;
int_status = ioread32(watchdog_device.timer_interrupt_status_addr);
pr_debug("irq, int_status: %x\n", int_status);
if (int_status != 0)
return IRQ_NONE;
/* has the timer been started? If not, then this is spurious */
if (watchdog_device.timer_started == 0) {
pr_debug("spurious interrupt received\n");
return IRQ_HANDLED;
}
/* temporarily disable the timer */
iowrite32(0x00000002, watchdog_device.timer_control_addr);
/* set the timer to the threshold */
iowrite32(watchdog_device.threshold,
watchdog_device.timer_load_count_addr);
/* allow the timer to run */
iowrite32(0x00000003, watchdog_device.timer_control_addr);
return IRQ_HANDLED;
}
static int intel_scu_keepalive(void)
{
/* read eoi register - clears interrupt */
ioread32(watchdog_device.timer_clear_interrupt_addr);
/* temporarily disable the timer */
iowrite32(0x00000002, watchdog_device.timer_control_addr);
/* set the timer to the soft_threshold */
iowrite32(watchdog_device.soft_threshold,
watchdog_device.timer_load_count_addr);
/* allow the timer to run */
iowrite32(0x00000003, watchdog_device.timer_control_addr);
return 0;
}
static int intel_scu_stop(void)
{
iowrite32(0, watchdog_device.timer_control_addr);
return 0;
}
static int intel_scu_set_heartbeat(u32 t)
{
int ipc_ret;
int retry_count;
u32 soft_value;
u32 hw_value;
watchdog_device.timer_set = t;
watchdog_device.threshold =
timer_margin * watchdog_device.timer_tbl_ptr->freq_hz;
watchdog_device.soft_threshold =
(watchdog_device.timer_set - timer_margin)
* watchdog_device.timer_tbl_ptr->freq_hz;
pr_debug("set_heartbeat: timer freq is %d\n",
watchdog_device.timer_tbl_ptr->freq_hz);
pr_debug("set_heartbeat: timer_set is %x (hex)\n",
watchdog_device.timer_set);
pr_debug("set_heartbeat: timer_margin is %x (hex)\n", timer_margin);
pr_debug("set_heartbeat: threshold is %x (hex)\n",
watchdog_device.threshold);
pr_debug("set_heartbeat: soft_threshold is %x (hex)\n",
watchdog_device.soft_threshold);
/* Adjust thresholds by FREQ_ADJUSTMENT factor, to make the */
/* watchdog timing come out right. */
watchdog_device.threshold =
watchdog_device.threshold / FREQ_ADJUSTMENT;
watchdog_device.soft_threshold =
watchdog_device.soft_threshold / FREQ_ADJUSTMENT;
/* temporarily disable the timer */
iowrite32(0x00000002, watchdog_device.timer_control_addr);
/* send the threshold and soft_threshold via IPC to the processor */
ipc_ret = watchdog_set_ipc(watchdog_device.soft_threshold,
watchdog_device.threshold);
if (ipc_ret != 0) {
/* Make sure the watchdog timer is stopped */
intel_scu_stop();
return ipc_ret;
}
/* Soft Threshold set loop. Early versions of silicon did */
/* not always set this count correctly. This loop checks */
/* the value and retries if it was not set correctly. */
retry_count = 0;
soft_value = watchdog_device.soft_threshold & 0xFFFF0000;
do {
/* Make sure timer is stopped */
intel_scu_stop();
if (MAX_RETRY < retry_count++) {
/* Unable to set timer value */
pr_err("Unable to set timer\n");
return -ENODEV;
}
/* set the timer to the soft threshold */
iowrite32(watchdog_device.soft_threshold,
watchdog_device.timer_load_count_addr);
/* read count value before starting timer */
ioread32(watchdog_device.timer_load_count_addr);
/* Start the timer */
iowrite32(0x00000003, watchdog_device.timer_control_addr);
/* read the value the time loaded into its count reg */
hw_value = ioread32(watchdog_device.timer_load_count_addr);
hw_value = hw_value & 0xFFFF0000;
} while (soft_value != hw_value);
watchdog_device.timer_started = 1;
return 0;
}
/*
* /dev/watchdog handling
*/
static int intel_scu_open(struct inode *inode, struct file *file)
{
/* Set flag to indicate that watchdog device is open */
if (test_and_set_bit(0, &watchdog_device.driver_open))
return -EBUSY;
/* Check for reopen of driver. Reopens are not allowed */
if (watchdog_device.driver_closed)
return -EPERM;
*: convert stream-like files from nonseekable_open -> stream_open Using scripts/coccinelle/api/stream_open.cocci added in 10dce8af3422 ("fs: stream_open - opener for stream-like files so that read and write can run simultaneously without deadlock"), search and convert to stream_open all in-kernel nonseekable_open users for which read and write actually do not depend on ppos and where there is no other methods in file_operations which assume @offset access. I've verified each generated change manually - that it is correct to convert - and each other nonseekable_open instance left - that it is either not correct to convert there, or that it is not converted due to current stream_open.cocci limitations. The script also does not convert files that should be valid to convert, but that currently have .llseek = noop_llseek or generic_file_llseek for unknown reason despite file being opened with nonseekable_open (e.g. drivers/input/mousedev.c) Among cases converted 14 were potentially vulnerable to read vs write deadlock (see details in 10dce8af3422): drivers/char/pcmcia/cm4000_cs.c:1685:7-23: ERROR: cm4000_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/gnss/core.c:45:1-17: ERROR: gnss_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/hid/uhid.c:635:1-17: ERROR: uhid_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/infiniband/core/user_mad.c:988:1-17: ERROR: umad_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/input/evdev.c:527:1-17: ERROR: evdev_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/input/misc/uinput.c:401:1-17: ERROR: uinput_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/isdn/capi/capi.c:963:8-24: ERROR: capi_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/leds/uleds.c:77:1-17: ERROR: uleds_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/media/rc/lirc_dev.c:198:1-17: ERROR: lirc_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/s390/char/fs3270.c:488:1-17: ERROR: fs3270_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/usb/misc/ldusb.c:310:1-17: ERROR: ld_usb_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. drivers/xen/evtchn.c:667:8-24: ERROR: evtchn_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. net/batman-adv/icmp_socket.c:80:1-17: ERROR: batadv_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. net/rfkill/core.c:1146:8-24: ERROR: rfkill_fops: .read() can deadlock .write(); change nonseekable_open -> stream_open to fix. and the rest were just safe to convert to stream_open because their read and write do not use ppos at all and corresponding file_operations do not have methods that assume @offset file access(*): arch/powerpc/platforms/52xx/mpc52xx_gpt.c:631:8-24: WARNING: mpc52xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_ibox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_mbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/powerpc/platforms/cell/spufs/file.c:591:8-24: WARNING: spufs_wbox_stat_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. arch/um/drivers/harddog_kern.c:88:8-24: WARNING: harddog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. arch/x86/kernel/cpu/microcode/core.c:430:33-49: WARNING: microcode_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/ds1620.c:215:8-24: WARNING: ds1620_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/dtlk.c:301:1-17: WARNING: dtlk_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/ipmi/ipmi_watchdog.c:840:9-25: WARNING: ipmi_wdog_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/pcmcia/scr24x_cs.c:95:8-24: WARNING: scr24x_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/char/tb0219.c:246:9-25: WARNING: tb0219_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/firewire/nosy.c:306:8-24: WARNING: nosy_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/hwmon/fschmd.c:840:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/hwmon/w83793.c:1344:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/ucma.c:1747:8-24: WARNING: ucma_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/ucm.c:1178:8-24: WARNING: ucm_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/infiniband/core/uverbs_main.c:1086:8-24: WARNING: uverbs_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/input/joydev.c:282:1-17: WARNING: joydev_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/pci/switch/switchtec.c:393:1-17: WARNING: switchtec_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/platform/chrome/cros_ec_debugfs.c:135:8-24: WARNING: cros_ec_console_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/rtc/rtc-ds1374.c:470:9-25: WARNING: ds1374_wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/rtc/rtc-m41t80.c:805:9-25: WARNING: wdt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/char/tape_char.c:293:2-18: WARNING: tape_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/char/zcore.c:194:8-24: WARNING: zcore_reipl_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/s390/crypto/zcrypt_api.c:528:8-24: WARNING: zcrypt_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/spi/spidev.c:594:1-17: WARNING: spidev_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/staging/pi433/pi433_if.c:974:1-17: WARNING: pi433_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/acquirewdt.c:203:8-24: WARNING: acq_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/advantechwdt.c:202:8-24: WARNING: advwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/alim1535_wdt.c:252:8-24: WARNING: ali_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/alim7101_wdt.c:217:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ar7_wdt.c:166:8-24: WARNING: ar7_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/at91rm9200_wdt.c:113:8-24: WARNING: at91wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ath79_wdt.c:135:8-24: WARNING: ath79_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/bcm63xx_wdt.c:119:8-24: WARNING: bcm63xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/cpu5wdt.c:143:8-24: WARNING: cpu5wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/cpwd.c:397:8-24: WARNING: cpwd_fops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/eurotechwdt.c:319:8-24: WARNING: eurwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/f71808e_wdt.c:528:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/gef_wdt.c:232:8-24: WARNING: gef_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/geodewdt.c:95:8-24: WARNING: geodewdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ib700wdt.c:241:8-24: WARNING: ibwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ibmasr.c:326:8-24: WARNING: asr_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/indydog.c:80:8-24: WARNING: indydog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/intel_scu_watchdog.c:307:8-24: WARNING: intel_scu_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/iop_wdt.c:104:8-24: WARNING: iop_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/it8712f_wdt.c:330:8-24: WARNING: it8712f_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ixp4xx_wdt.c:68:8-24: WARNING: ixp4xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/ks8695_wdt.c:145:8-24: WARNING: ks8695wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/m54xx_wdt.c:88:8-24: WARNING: m54xx_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/machzwd.c:336:8-24: WARNING: zf_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mixcomwd.c:153:8-24: WARNING: mixcomwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mtx-1_wdt.c:121:8-24: WARNING: mtx1_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/mv64x60_wdt.c:136:8-24: WARNING: mv64x60_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/nuc900_wdt.c:134:8-24: WARNING: nuc900wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/nv_tco.c:164:8-24: WARNING: nv_tco_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pc87413_wdt.c:289:8-24: WARNING: pc87413_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd.c:698:8-24: WARNING: pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd.c:737:8-24: WARNING: pcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_pci.c:581:8-24: WARNING: pcipcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_pci.c:623:8-24: WARNING: pcipcwd_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_usb.c:488:8-24: WARNING: usb_pcwd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pcwd_usb.c:527:8-24: WARNING: usb_pcwd_temperature_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pika_wdt.c:121:8-24: WARNING: pikawdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/pnx833x_wdt.c:119:8-24: WARNING: pnx833x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/rc32434_wdt.c:153:8-24: WARNING: rc32434_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/rdc321x_wdt.c:145:8-24: WARNING: rdc321x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/riowd.c:79:1-17: WARNING: riowd_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sa1100_wdt.c:62:8-24: WARNING: sa1100dog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc60xxwdt.c:211:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc7240_wdt.c:139:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc8360.c:274:8-24: WARNING: sbc8360_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc_epx_c3.c:81:8-24: WARNING: epx_c3_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sbc_fitpc2_wdt.c:78:8-24: WARNING: fitpc2_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sb_wdog.c:108:1-17: WARNING: sbwdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sc1200wdt.c:181:8-24: WARNING: sc1200wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sc520_wdt.c:261:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/sch311x_wdt.c:319:8-24: WARNING: sch311x_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/scx200_wdt.c:105:8-24: WARNING: scx200_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/smsc37b787_wdt.c:369:8-24: WARNING: wb_smsc_wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/w83877f_wdt.c:227:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/w83977f_wdt.c:301:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wafer5823wdt.c:200:8-24: WARNING: wafwdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/watchdog_dev.c:828:8-24: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdrtas.c:379:8-24: WARNING: wdrtas_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdrtas.c:445:8-24: WARNING: wdrtas_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt285.c:104:1-17: WARNING: watchdog_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt977.c:276:8-24: WARNING: wdt977_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt.c:424:8-24: WARNING: wdt_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt.c:484:8-24: WARNING: wdt_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt_pci.c:464:8-24: WARNING: wdtpci_fops: .write() has stream semantic; safe to change nonseekable_open -> stream_open. drivers/watchdog/wdt_pci.c:527:8-24: WARNING: wdtpci_temp_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. net/batman-adv/log.c:105:1-17: WARNING: batadv_log_fops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. sound/core/control.c:57:7-23: WARNING: snd_ctl_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. sound/core/rawmidi.c:385:7-23: WARNING: snd_rawmidi_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. sound/core/seq/seq_clientmgr.c:310:7-23: WARNING: snd_seq_f_ops: .read() and .write() have stream semantic; safe to change nonseekable_open -> stream_open. sound/core/timer.c:1428:7-23: WARNING: snd_timer_f_ops: .read() has stream semantic; safe to change nonseekable_open -> stream_open. One can also recheck/review the patch via generating it with explanation comments included via $ make coccicheck MODE=patch COCCI=scripts/coccinelle/api/stream_open.cocci SPFLAGS="-D explain" (*) This second group also contains cases with read/write deadlocks that stream_open.cocci don't yet detect, but which are still valid to convert to stream_open since ppos is not used. For example drivers/pci/switch/switchtec.c calls wait_for_completion_interruptible() in its .read, but stream_open.cocci currently detects only "wait_event*" as blocking. Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yongzhi Pan <panyongzhi@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Juergen Gross <jgross@suse.com> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Tejun Heo <tj@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Julia Lawall <Julia.Lawall@lip6.fr> Cc: Nikolaus Rath <Nikolaus@rath.org> Cc: Han-Wen Nienhuys <hanwen@google.com> Cc: Anatolij Gustschin <agust@denx.de> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "James R. Van Zandt" <jrv@vanzandt.mv.com> Cc: Corey Minyard <minyard@acm.org> Cc: Harald Welte <laforge@gnumonks.org> Acked-by: Lubomir Rintel <lkundrak@v3.sk> [scr24x_cs] Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Johan Hovold <johan@kernel.org> Cc: David Herrmann <dh.herrmann@googlemail.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: Jean Delvare <jdelvare@suse.com> Acked-by: Guenter Roeck <linux@roeck-us.net> [watchdog/* hwmon/*] Cc: Rudolf Marek <r.marek@assembler.cz> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Karsten Keil <isdn@linux-pingi.de> Cc: Jacek Anaszewski <jacek.anaszewski@gmail.com> Cc: Pavel Machek <pavel@ucw.cz> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Kurt Schwemmer <kurt.schwemmer@microsemi.com> Acked-by: Logan Gunthorpe <logang@deltatee.com> [drivers/pci/switch/switchtec] Acked-by: Bjorn Helgaas <bhelgaas@google.com> [drivers/pci/switch/switchtec] Cc: Benson Leung <bleung@chromium.org> Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> [platform/chrome] Cc: Alessandro Zummo <a.zummo@towertech.it> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> [rtc/*] Cc: Mark Brown <broonie@kernel.org> Cc: Wim Van Sebroeck <wim@linux-watchdog.org> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: Wan ZongShun <mcuos.com@gmail.com> Cc: Zwane Mwaikambo <zwanem@gmail.com> Cc: Marek Lindner <mareklindner@neomailbox.ch> Cc: Simon Wunderlich <sw@simonwunderlich.de> Cc: Antonio Quartulli <a@unstable.cc> Cc: "David S. Miller" <davem@davemloft.net> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.com> Signed-off-by: Kirill Smelkov <kirr@nexedi.com>
2019-03-26 20:51:19 +00:00
return stream_open(inode, file);
}
static int intel_scu_release(struct inode *inode, struct file *file)
{
/*
* This watchdog should not be closed, after the timer
* is started with the WDIPC_SETTIMEOUT ioctl
* If force_boot is set watchdog_fire() will cause an
* immediate reset. If force_boot is not set, the watchdog
* timer is refreshed for one more interval. At the end
* of that interval, the watchdog timer will reset the system.
*/
if (!test_and_clear_bit(0, &watchdog_device.driver_open)) {
pr_debug("intel_scu_release, without open\n");
return -ENOTTY;
}
if (!watchdog_device.timer_started) {
/* Just close, since timer has not been started */
pr_debug("closed, without starting timer\n");
return 0;
}
pr_crit("Unexpected close of /dev/watchdog!\n");
/* Since the timer was started, prevent future reopens */
watchdog_device.driver_closed = 1;
/* Refresh the timer for one more interval */
intel_scu_keepalive();
/* Reboot system (if force_boot is set) */
watchdog_fire();
/* We should only reach this point if force_boot is not set */
return 0;
}
static ssize_t intel_scu_write(struct file *file,
char const *data,
size_t len,
loff_t *ppos)
{
if (watchdog_device.timer_started)
/* Watchdog already started, keep it alive */
intel_scu_keepalive();
else
/* Start watchdog with timer value set by init */
intel_scu_set_heartbeat(watchdog_device.timer_set);
return len;
}
static long intel_scu_ioctl(struct file *file,
unsigned int cmd,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
u32 __user *p = argp;
u32 new_margin;
static const struct watchdog_info ident = {
.options = WDIOF_SETTIMEOUT
| WDIOF_KEEPALIVEPING,
.firmware_version = 0, /* @todo Get from SCU via
ipc_get_scu_fw_version()? */
.identity = "Intel_SCU IOH Watchdog" /* len < 32 */
};
switch (cmd) {
case WDIOC_GETSUPPORT:
return copy_to_user(argp,
&ident,
sizeof(ident)) ? -EFAULT : 0;
case WDIOC_GETSTATUS:
case WDIOC_GETBOOTSTATUS:
return put_user(0, p);
case WDIOC_KEEPALIVE:
intel_scu_keepalive();
return 0;
case WDIOC_SETTIMEOUT:
if (get_user(new_margin, p))
return -EFAULT;
if (check_timer_margin(new_margin))
return -EINVAL;
if (intel_scu_set_heartbeat(new_margin))
return -EINVAL;
return 0;
case WDIOC_GETTIMEOUT:
return put_user(watchdog_device.soft_threshold, p);
default:
return -ENOTTY;
}
}
/*
* Notifier for system down
*/
static int intel_scu_notify_sys(struct notifier_block *this,
unsigned long code,
void *another_unused)
{
if (code == SYS_DOWN || code == SYS_HALT)
/* Turn off the watchdog timer. */
intel_scu_stop();
return NOTIFY_DONE;
}
/*
* Kernel Interfaces
*/
static const struct file_operations intel_scu_fops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.write = intel_scu_write,
.unlocked_ioctl = intel_scu_ioctl,
.open = intel_scu_open,
.release = intel_scu_release,
};
static int __init intel_scu_watchdog_init(void)
{
int ret;
u32 __iomem *tmp_addr;
/*
* We don't really need to check this as the SFI timer get will fail
* but if we do so we can exit with a clearer reason and no noise.
*
* If it isn't an intel MID device then it doesn't have this watchdog
*/
if (!intel_mid_identify_cpu())
return -ENODEV;
/* Check boot parameters to verify that their initial values */
/* are in range. */
/* Check value of timer_set boot parameter */
if ((timer_set < MIN_TIME_CYCLE) ||
(timer_set > MAX_TIME - MIN_TIME_CYCLE)) {
pr_err("value of timer_set %x (hex) is out of range from %x to %x (hex)\n",
timer_set, MIN_TIME_CYCLE, MAX_TIME - MIN_TIME_CYCLE);
return -EINVAL;
}
/* Check value of timer_margin boot parameter */
if (check_timer_margin(timer_margin))
return -EINVAL;
watchdog_device.timer_tbl_ptr = sfi_get_mtmr(sfi_mtimer_num-1);
if (watchdog_device.timer_tbl_ptr == NULL) {
pr_debug("timer is not available\n");
return -ENODEV;
}
/* make sure the timer exists */
if (watchdog_device.timer_tbl_ptr->phys_addr == 0) {
pr_debug("timer %d does not have valid physical memory\n",
sfi_mtimer_num);
return -ENODEV;
}
if (watchdog_device.timer_tbl_ptr->irq == 0) {
pr_debug("timer %d invalid irq\n", sfi_mtimer_num);
return -ENODEV;
}
tmp_addr = ioremap_nocache(watchdog_device.timer_tbl_ptr->phys_addr,
20);
if (tmp_addr == NULL) {
pr_debug("timer unable to ioremap\n");
return -ENOMEM;
}
watchdog_device.timer_load_count_addr = tmp_addr++;
watchdog_device.timer_current_value_addr = tmp_addr++;
watchdog_device.timer_control_addr = tmp_addr++;
watchdog_device.timer_clear_interrupt_addr = tmp_addr++;
watchdog_device.timer_interrupt_status_addr = tmp_addr++;
/* Set the default time values in device structure */
watchdog_device.timer_set = timer_set;
watchdog_device.threshold =
timer_margin * watchdog_device.timer_tbl_ptr->freq_hz;
watchdog_device.soft_threshold =
(watchdog_device.timer_set - timer_margin)
* watchdog_device.timer_tbl_ptr->freq_hz;
watchdog_device.intel_scu_notifier.notifier_call =
intel_scu_notify_sys;
ret = register_reboot_notifier(&watchdog_device.intel_scu_notifier);
if (ret) {
pr_err("cannot register notifier %d)\n", ret);
goto register_reboot_error;
}
watchdog_device.miscdev.minor = WATCHDOG_MINOR;
watchdog_device.miscdev.name = "watchdog";
watchdog_device.miscdev.fops = &intel_scu_fops;
ret = misc_register(&watchdog_device.miscdev);
if (ret) {
pr_err("cannot register miscdev %d err =%d\n",
WATCHDOG_MINOR, ret);
goto misc_register_error;
}
ret = request_irq((unsigned int)watchdog_device.timer_tbl_ptr->irq,
watchdog_timer_interrupt,
IRQF_SHARED, "watchdog",
&watchdog_device.timer_load_count_addr);
if (ret) {
pr_err("error requesting irq %d\n", ret);
goto request_irq_error;
}
/* Make sure timer is disabled before returning */
intel_scu_stop();
return 0;
/* error cleanup */
request_irq_error:
misc_deregister(&watchdog_device.miscdev);
misc_register_error:
unregister_reboot_notifier(&watchdog_device.intel_scu_notifier);
register_reboot_error:
intel_scu_stop();
iounmap(watchdog_device.timer_load_count_addr);
return ret;
}
late_initcall(intel_scu_watchdog_init);