linux/drivers/watchdog/octeon-wdt-main.c
Guenter Roeck d017327893 watchdog: convert remaining drivers to use SPDX license identifier
This gets rid of the unnecessary license boilerplate, and avoids
having to deal with individual patches one by one.

No functional changes.

Reviewed-by: Jerry Hoemann <jerry.hoemann@hpe.com>
Acked-by: Sylvain Lemieux <slemieux.tyco@gmail.com>
Reviewed-by: Matthias Brugger <matthias.bgg@gmail.com>
Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Wim Van Sebroeck <wim@linux-watchdog.org>
2019-07-08 20:35:11 +02:00

611 lines
16 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Octeon Watchdog driver
*
* Copyright (C) 2007-2017 Cavium, Inc.
*
* Converted to use WATCHDOG_CORE by Aaro Koskinen <aaro.koskinen@iki.fi>.
*
* Some parts derived from wdt.c
*
* (c) Copyright 1996-1997 Alan Cox <alan@lxorguk.ukuu.org.uk>,
* All Rights Reserved.
*
* Neither Alan Cox nor CymruNet Ltd. admit liability nor provide
* warranty for any of this software. This material is provided
* "AS-IS" and at no charge.
*
* (c) Copyright 1995 Alan Cox <alan@lxorguk.ukuu.org.uk>
*
* The OCTEON watchdog has a maximum timeout of 2^32 * io_clock.
* For most systems this is less than 10 seconds, so to allow for
* software to request longer watchdog heartbeats, we maintain software
* counters to count multiples of the base rate. If the system locks
* up in such a manner that we can not run the software counters, the
* only result is a watchdog reset sooner than was requested. But
* that is OK, because in this case userspace would likely not be able
* to do anything anyhow.
*
* The hardware watchdog interval we call the period. The OCTEON
* watchdog goes through several stages, after the first period an
* irq is asserted, then if it is not reset, after the next period NMI
* is asserted, then after an additional period a chip wide soft reset.
* So for the software counters, we reset watchdog after each period
* and decrement the counter. But for the last two periods we need to
* let the watchdog progress to the NMI stage so we disable the irq
* and let it proceed. Once in the NMI, we print the register state
* to the serial port and then wait for the reset.
*
* A watchdog is maintained for each CPU in the system, that way if
* one CPU suffers a lockup, we also get a register dump and reset.
* The userspace ping resets the watchdog on all CPUs.
*
* Before userspace opens the watchdog device, we still run the
* watchdogs to catch any lockups that may be kernel related.
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/interrupt.h>
#include <linux/watchdog.h>
#include <linux/cpumask.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/cpu.h>
#include <linux/irq.h>
#include <asm/mipsregs.h>
#include <asm/uasm.h>
#include <asm/octeon/octeon.h>
#include <asm/octeon/cvmx-boot-vector.h>
#include <asm/octeon/cvmx-ciu2-defs.h>
#include <asm/octeon/cvmx-rst-defs.h>
/* Watchdog interrupt major block number (8 MSBs of intsn) */
#define WD_BLOCK_NUMBER 0x01
static int divisor;
/* The count needed to achieve timeout_sec. */
static unsigned int timeout_cnt;
/* The maximum period supported. */
static unsigned int max_timeout_sec;
/* The current period. */
static unsigned int timeout_sec;
/* Set to non-zero when userspace countdown mode active */
static bool do_countdown;
static unsigned int countdown_reset;
static unsigned int per_cpu_countdown[NR_CPUS];
static cpumask_t irq_enabled_cpus;
#define WD_TIMO 60 /* Default heartbeat = 60 seconds */
#define CVMX_GSERX_SCRATCH(offset) (CVMX_ADD_IO_SEG(0x0001180090000020ull) + ((offset) & 15) * 0x1000000ull)
static int heartbeat = WD_TIMO;
module_param(heartbeat, int, 0444);
MODULE_PARM_DESC(heartbeat,
"Watchdog heartbeat in seconds. (0 < heartbeat, default="
__MODULE_STRING(WD_TIMO) ")");
static bool nowayout = WATCHDOG_NOWAYOUT;
module_param(nowayout, bool, 0444);
MODULE_PARM_DESC(nowayout,
"Watchdog cannot be stopped once started (default="
__MODULE_STRING(WATCHDOG_NOWAYOUT) ")");
static int disable;
module_param(disable, int, 0444);
MODULE_PARM_DESC(disable,
"Disable the watchdog entirely (default=0)");
static struct cvmx_boot_vector_element *octeon_wdt_bootvector;
void octeon_wdt_nmi_stage2(void);
static int cpu2core(int cpu)
{
#ifdef CONFIG_SMP
return cpu_logical_map(cpu) & 0x3f;
#else
return cvmx_get_core_num();
#endif
}
/**
* Poke the watchdog when an interrupt is received
*
* @cpl:
* @dev_id:
*
* Returns
*/
static irqreturn_t octeon_wdt_poke_irq(int cpl, void *dev_id)
{
int cpu = raw_smp_processor_id();
unsigned int core = cpu2core(cpu);
int node = cpu_to_node(cpu);
if (do_countdown) {
if (per_cpu_countdown[cpu] > 0) {
/* We're alive, poke the watchdog */
cvmx_write_csr_node(node, CVMX_CIU_PP_POKEX(core), 1);
per_cpu_countdown[cpu]--;
} else {
/* Bad news, you are about to reboot. */
disable_irq_nosync(cpl);
cpumask_clear_cpu(cpu, &irq_enabled_cpus);
}
} else {
/* Not open, just ping away... */
cvmx_write_csr_node(node, CVMX_CIU_PP_POKEX(core), 1);
}
return IRQ_HANDLED;
}
/* From setup.c */
extern int prom_putchar(char c);
/**
* Write a string to the uart
*
* @str: String to write
*/
static void octeon_wdt_write_string(const char *str)
{
/* Just loop writing one byte at a time */
while (*str)
prom_putchar(*str++);
}
/**
* Write a hex number out of the uart
*
* @value: Number to display
* @digits: Number of digits to print (1 to 16)
*/
static void octeon_wdt_write_hex(u64 value, int digits)
{
int d;
int v;
for (d = 0; d < digits; d++) {
v = (value >> ((digits - d - 1) * 4)) & 0xf;
if (v >= 10)
prom_putchar('a' + v - 10);
else
prom_putchar('0' + v);
}
}
static const char reg_name[][3] = {
"$0", "at", "v0", "v1", "a0", "a1", "a2", "a3",
"a4", "a5", "a6", "a7", "t0", "t1", "t2", "t3",
"s0", "s1", "s2", "s3", "s4", "s5", "s6", "s7",
"t8", "t9", "k0", "k1", "gp", "sp", "s8", "ra"
};
/**
* NMI stage 3 handler. NMIs are handled in the following manner:
* 1) The first NMI handler enables CVMSEG and transfers from
* the bootbus region into normal memory. It is careful to not
* destroy any registers.
* 2) The second stage handler uses CVMSEG to save the registers
* and create a stack for C code. It then calls the third level
* handler with one argument, a pointer to the register values.
* 3) The third, and final, level handler is the following C
* function that prints out some useful infomration.
*
* @reg: Pointer to register state before the NMI
*/
void octeon_wdt_nmi_stage3(u64 reg[32])
{
u64 i;
unsigned int coreid = cvmx_get_core_num();
/*
* Save status and cause early to get them before any changes
* might happen.
*/
u64 cp0_cause = read_c0_cause();
u64 cp0_status = read_c0_status();
u64 cp0_error_epc = read_c0_errorepc();
u64 cp0_epc = read_c0_epc();
/* Delay so output from all cores output is not jumbled together. */
udelay(85000 * coreid);
octeon_wdt_write_string("\r\n*** NMI Watchdog interrupt on Core 0x");
octeon_wdt_write_hex(coreid, 2);
octeon_wdt_write_string(" ***\r\n");
for (i = 0; i < 32; i++) {
octeon_wdt_write_string("\t");
octeon_wdt_write_string(reg_name[i]);
octeon_wdt_write_string("\t0x");
octeon_wdt_write_hex(reg[i], 16);
if (i & 1)
octeon_wdt_write_string("\r\n");
}
octeon_wdt_write_string("\terr_epc\t0x");
octeon_wdt_write_hex(cp0_error_epc, 16);
octeon_wdt_write_string("\tepc\t0x");
octeon_wdt_write_hex(cp0_epc, 16);
octeon_wdt_write_string("\r\n");
octeon_wdt_write_string("\tstatus\t0x");
octeon_wdt_write_hex(cp0_status, 16);
octeon_wdt_write_string("\tcause\t0x");
octeon_wdt_write_hex(cp0_cause, 16);
octeon_wdt_write_string("\r\n");
/* The CIU register is different for each Octeon model. */
if (OCTEON_IS_MODEL(OCTEON_CN68XX)) {
octeon_wdt_write_string("\tsrc_wd\t0x");
octeon_wdt_write_hex(cvmx_read_csr(CVMX_CIU2_SRC_PPX_IP2_WDOG(coreid)), 16);
octeon_wdt_write_string("\ten_wd\t0x");
octeon_wdt_write_hex(cvmx_read_csr(CVMX_CIU2_EN_PPX_IP2_WDOG(coreid)), 16);
octeon_wdt_write_string("\r\n");
octeon_wdt_write_string("\tsrc_rml\t0x");
octeon_wdt_write_hex(cvmx_read_csr(CVMX_CIU2_SRC_PPX_IP2_RML(coreid)), 16);
octeon_wdt_write_string("\ten_rml\t0x");
octeon_wdt_write_hex(cvmx_read_csr(CVMX_CIU2_EN_PPX_IP2_RML(coreid)), 16);
octeon_wdt_write_string("\r\n");
octeon_wdt_write_string("\tsum\t0x");
octeon_wdt_write_hex(cvmx_read_csr(CVMX_CIU2_SUM_PPX_IP2(coreid)), 16);
octeon_wdt_write_string("\r\n");
} else if (!octeon_has_feature(OCTEON_FEATURE_CIU3)) {
octeon_wdt_write_string("\tsum0\t0x");
octeon_wdt_write_hex(cvmx_read_csr(CVMX_CIU_INTX_SUM0(coreid * 2)), 16);
octeon_wdt_write_string("\ten0\t0x");
octeon_wdt_write_hex(cvmx_read_csr(CVMX_CIU_INTX_EN0(coreid * 2)), 16);
octeon_wdt_write_string("\r\n");
}
octeon_wdt_write_string("*** Chip soft reset soon ***\r\n");
/*
* G-30204: We must trigger a soft reset before watchdog
* does an incomplete job of doing it.
*/
if (OCTEON_IS_OCTEON3() && !OCTEON_IS_MODEL(OCTEON_CN70XX)) {
u64 scr;
unsigned int node = cvmx_get_node_num();
unsigned int lcore = cvmx_get_local_core_num();
union cvmx_ciu_wdogx ciu_wdog;
/*
* Wait for other cores to print out information, but
* not too long. Do the soft reset before watchdog
* can trigger it.
*/
do {
ciu_wdog.u64 = cvmx_read_csr_node(node, CVMX_CIU_WDOGX(lcore));
} while (ciu_wdog.s.cnt > 0x10000);
scr = cvmx_read_csr_node(0, CVMX_GSERX_SCRATCH(0));
scr |= 1 << 11; /* Indicate watchdog in bit 11 */
cvmx_write_csr_node(0, CVMX_GSERX_SCRATCH(0), scr);
cvmx_write_csr_node(0, CVMX_RST_SOFT_RST, 1);
}
}
static int octeon_wdt_cpu_to_irq(int cpu)
{
unsigned int coreid;
int node;
int irq;
coreid = cpu2core(cpu);
node = cpu_to_node(cpu);
if (octeon_has_feature(OCTEON_FEATURE_CIU3)) {
struct irq_domain *domain;
int hwirq;
domain = octeon_irq_get_block_domain(node,
WD_BLOCK_NUMBER);
hwirq = WD_BLOCK_NUMBER << 12 | 0x200 | coreid;
irq = irq_find_mapping(domain, hwirq);
} else {
irq = OCTEON_IRQ_WDOG0 + coreid;
}
return irq;
}
static int octeon_wdt_cpu_pre_down(unsigned int cpu)
{
unsigned int core;
int node;
union cvmx_ciu_wdogx ciu_wdog;
core = cpu2core(cpu);
node = cpu_to_node(cpu);
/* Poke the watchdog to clear out its state */
cvmx_write_csr_node(node, CVMX_CIU_PP_POKEX(core), 1);
/* Disable the hardware. */
ciu_wdog.u64 = 0;
cvmx_write_csr_node(node, CVMX_CIU_WDOGX(core), ciu_wdog.u64);
free_irq(octeon_wdt_cpu_to_irq(cpu), octeon_wdt_poke_irq);
return 0;
}
static int octeon_wdt_cpu_online(unsigned int cpu)
{
unsigned int core;
unsigned int irq;
union cvmx_ciu_wdogx ciu_wdog;
int node;
struct irq_domain *domain;
int hwirq;
core = cpu2core(cpu);
node = cpu_to_node(cpu);
octeon_wdt_bootvector[core].target_ptr = (u64)octeon_wdt_nmi_stage2;
/* Disable it before doing anything with the interrupts. */
ciu_wdog.u64 = 0;
cvmx_write_csr_node(node, CVMX_CIU_WDOGX(core), ciu_wdog.u64);
per_cpu_countdown[cpu] = countdown_reset;
if (octeon_has_feature(OCTEON_FEATURE_CIU3)) {
/* Must get the domain for the watchdog block */
domain = octeon_irq_get_block_domain(node, WD_BLOCK_NUMBER);
/* Get a irq for the wd intsn (hardware interrupt) */
hwirq = WD_BLOCK_NUMBER << 12 | 0x200 | core;
irq = irq_create_mapping(domain, hwirq);
irqd_set_trigger_type(irq_get_irq_data(irq),
IRQ_TYPE_EDGE_RISING);
} else
irq = OCTEON_IRQ_WDOG0 + core;
if (request_irq(irq, octeon_wdt_poke_irq,
IRQF_NO_THREAD, "octeon_wdt", octeon_wdt_poke_irq))
panic("octeon_wdt: Couldn't obtain irq %d", irq);
/* Must set the irq affinity here */
if (octeon_has_feature(OCTEON_FEATURE_CIU3)) {
cpumask_t mask;
cpumask_clear(&mask);
cpumask_set_cpu(cpu, &mask);
irq_set_affinity(irq, &mask);
}
cpumask_set_cpu(cpu, &irq_enabled_cpus);
/* Poke the watchdog to clear out its state */
cvmx_write_csr_node(node, CVMX_CIU_PP_POKEX(core), 1);
/* Finally enable the watchdog now that all handlers are installed */
ciu_wdog.u64 = 0;
ciu_wdog.s.len = timeout_cnt;
ciu_wdog.s.mode = 3; /* 3 = Interrupt + NMI + Soft-Reset */
cvmx_write_csr_node(node, CVMX_CIU_WDOGX(core), ciu_wdog.u64);
return 0;
}
static int octeon_wdt_ping(struct watchdog_device __always_unused *wdog)
{
int cpu;
int coreid;
int node;
if (disable)
return 0;
for_each_online_cpu(cpu) {
coreid = cpu2core(cpu);
node = cpu_to_node(cpu);
cvmx_write_csr_node(node, CVMX_CIU_PP_POKEX(coreid), 1);
per_cpu_countdown[cpu] = countdown_reset;
if ((countdown_reset || !do_countdown) &&
!cpumask_test_cpu(cpu, &irq_enabled_cpus)) {
/* We have to enable the irq */
enable_irq(octeon_wdt_cpu_to_irq(cpu));
cpumask_set_cpu(cpu, &irq_enabled_cpus);
}
}
return 0;
}
static void octeon_wdt_calc_parameters(int t)
{
unsigned int periods;
timeout_sec = max_timeout_sec;
/*
* Find the largest interrupt period, that can evenly divide
* the requested heartbeat time.
*/
while ((t % timeout_sec) != 0)
timeout_sec--;
periods = t / timeout_sec;
/*
* The last two periods are after the irq is disabled, and
* then to the nmi, so we subtract them off.
*/
countdown_reset = periods > 2 ? periods - 2 : 0;
heartbeat = t;
timeout_cnt = ((octeon_get_io_clock_rate() / divisor) * timeout_sec) >> 8;
}
static int octeon_wdt_set_timeout(struct watchdog_device *wdog,
unsigned int t)
{
int cpu;
int coreid;
union cvmx_ciu_wdogx ciu_wdog;
int node;
if (t <= 0)
return -1;
octeon_wdt_calc_parameters(t);
if (disable)
return 0;
for_each_online_cpu(cpu) {
coreid = cpu2core(cpu);
node = cpu_to_node(cpu);
cvmx_write_csr_node(node, CVMX_CIU_PP_POKEX(coreid), 1);
ciu_wdog.u64 = 0;
ciu_wdog.s.len = timeout_cnt;
ciu_wdog.s.mode = 3; /* 3 = Interrupt + NMI + Soft-Reset */
cvmx_write_csr_node(node, CVMX_CIU_WDOGX(coreid), ciu_wdog.u64);
cvmx_write_csr_node(node, CVMX_CIU_PP_POKEX(coreid), 1);
}
octeon_wdt_ping(wdog); /* Get the irqs back on. */
return 0;
}
static int octeon_wdt_start(struct watchdog_device *wdog)
{
octeon_wdt_ping(wdog);
do_countdown = 1;
return 0;
}
static int octeon_wdt_stop(struct watchdog_device *wdog)
{
do_countdown = 0;
octeon_wdt_ping(wdog);
return 0;
}
static const struct watchdog_info octeon_wdt_info = {
.options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | WDIOF_KEEPALIVEPING,
.identity = "OCTEON",
};
static const struct watchdog_ops octeon_wdt_ops = {
.owner = THIS_MODULE,
.start = octeon_wdt_start,
.stop = octeon_wdt_stop,
.ping = octeon_wdt_ping,
.set_timeout = octeon_wdt_set_timeout,
};
static struct watchdog_device octeon_wdt = {
.info = &octeon_wdt_info,
.ops = &octeon_wdt_ops,
};
static enum cpuhp_state octeon_wdt_online;
/**
* Module/ driver initialization.
*
* Returns Zero on success
*/
static int __init octeon_wdt_init(void)
{
int ret;
octeon_wdt_bootvector = cvmx_boot_vector_get();
if (!octeon_wdt_bootvector) {
pr_err("Error: Cannot allocate boot vector.\n");
return -ENOMEM;
}
if (OCTEON_IS_MODEL(OCTEON_CN68XX))
divisor = 0x200;
else if (OCTEON_IS_MODEL(OCTEON_CN78XX))
divisor = 0x400;
else
divisor = 0x100;
/*
* Watchdog time expiration length = The 16 bits of LEN
* represent the most significant bits of a 24 bit decrementer
* that decrements every divisor cycle.
*
* Try for a timeout of 5 sec, if that fails a smaller number
* of even seconds,
*/
max_timeout_sec = 6;
do {
max_timeout_sec--;
timeout_cnt = ((octeon_get_io_clock_rate() / divisor) * max_timeout_sec) >> 8;
} while (timeout_cnt > 65535);
BUG_ON(timeout_cnt == 0);
octeon_wdt_calc_parameters(heartbeat);
pr_info("Initial granularity %d Sec\n", timeout_sec);
octeon_wdt.timeout = timeout_sec;
octeon_wdt.max_timeout = UINT_MAX;
watchdog_set_nowayout(&octeon_wdt, nowayout);
ret = watchdog_register_device(&octeon_wdt);
if (ret) {
pr_err("watchdog_register_device() failed: %d\n", ret);
return ret;
}
if (disable) {
pr_notice("disabled\n");
return 0;
}
cpumask_clear(&irq_enabled_cpus);
ret = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "watchdog/octeon:online",
octeon_wdt_cpu_online, octeon_wdt_cpu_pre_down);
if (ret < 0)
goto err;
octeon_wdt_online = ret;
return 0;
err:
cvmx_write_csr(CVMX_MIO_BOOT_LOC_CFGX(0), 0);
watchdog_unregister_device(&octeon_wdt);
return ret;
}
/**
* Module / driver shutdown
*/
static void __exit octeon_wdt_cleanup(void)
{
watchdog_unregister_device(&octeon_wdt);
if (disable)
return;
cpuhp_remove_state(octeon_wdt_online);
/*
* Disable the boot-bus memory, the code it points to is soon
* to go missing.
*/
cvmx_write_csr(CVMX_MIO_BOOT_LOC_CFGX(0), 0);
}
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Cavium Inc. <support@cavium.com>");
MODULE_DESCRIPTION("Cavium Inc. OCTEON Watchdog driver.");
module_init(octeon_wdt_init);
module_exit(octeon_wdt_cleanup);