Adding upstream version 4.19.249.upstream/4.19.249

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 619 insertions, 0 deletions

diff --git a/drivers/watchdog/octeon-wdt-main.c b/drivers/watchdog/octeon-wdt-main.c
new file mode 100644
index 000000000..0ec419a3f
--- /dev/null
+++ b/drivers/watchdog/octeon-wdt-main.c
@@ -0,0 +1,619 @@
+/*
+ * 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.
+ *
+ *	This program is free software; you can redistribute it and/or
+ *	modify it under the terms of the GNU General Public License
+ *	as published by the Free Software Foundation; either version
+ *	2 of the License, or (at your option) any later version.
+ *
+ *	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>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ *
+ * 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);