linux/arch/powerpc/platforms/83xx/misc.c
Christophe Leroy 0deae39cec powerpc/83xx: handle machine check caused by watchdog timer
When the watchdog timer is set in interrupt mode, it causes a
machine check when it times out. The purpose of this mode is to
ease debugging, not to crash the kernel and reboot the machine.

This patch implements a special handling for that, in order to not
crash the kernel if the watchdog times out while in interrupt or
within the idle task.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
[scottwood: added missing #include]
Signed-off-by: Scott Wood <oss@buserror.net>
2018-12-21 20:56:41 -06:00

170 lines
3.6 KiB
C

/*
* misc setup functions for MPC83xx
*
* Maintainer: Kumar Gala <galak@kernel.crashing.org>
*
* 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.
*/
#include <linux/stddef.h>
#include <linux/kernel.h>
#include <linux/of_platform.h>
#include <linux/pci.h>
#include <asm/debug.h>
#include <asm/io.h>
#include <asm/hw_irq.h>
#include <asm/ipic.h>
#include <soc/fsl/qe/qe_ic.h>
#include <sysdev/fsl_soc.h>
#include <sysdev/fsl_pci.h>
#include "mpc83xx.h"
static __be32 __iomem *restart_reg_base;
static int __init mpc83xx_restart_init(void)
{
/* map reset restart_reg_baseister space */
restart_reg_base = ioremap(get_immrbase() + 0x900, 0xff);
return 0;
}
arch_initcall(mpc83xx_restart_init);
void __noreturn mpc83xx_restart(char *cmd)
{
#define RST_OFFSET 0x00000900
#define RST_PROT_REG 0x00000018
#define RST_CTRL_REG 0x0000001c
local_irq_disable();
if (restart_reg_base) {
/* enable software reset "RSTE" */
out_be32(restart_reg_base + (RST_PROT_REG >> 2), 0x52535445);
/* set software hard reset */
out_be32(restart_reg_base + (RST_CTRL_REG >> 2), 0x2);
} else {
printk (KERN_EMERG "Error: Restart registers not mapped, spinning!\n");
}
for (;;) ;
}
long __init mpc83xx_time_init(void)
{
#define SPCR_OFFSET 0x00000110
#define SPCR_TBEN 0x00400000
__be32 __iomem *spcr = ioremap(get_immrbase() + SPCR_OFFSET, 4);
__be32 tmp;
tmp = in_be32(spcr);
out_be32(spcr, tmp | SPCR_TBEN);
iounmap(spcr);
return 0;
}
void __init mpc83xx_ipic_init_IRQ(void)
{
struct device_node *np;
/* looking for fsl,pq2pro-pic which is asl compatible with fsl,ipic */
np = of_find_compatible_node(NULL, NULL, "fsl,ipic");
if (!np)
np = of_find_node_by_type(NULL, "ipic");
if (!np)
return;
ipic_init(np, 0);
of_node_put(np);
/* Initialize the default interrupt mapping priorities,
* in case the boot rom changed something on us.
*/
ipic_set_default_priority();
}
#ifdef CONFIG_QUICC_ENGINE
void __init mpc83xx_qe_init_IRQ(void)
{
struct device_node *np;
np = of_find_compatible_node(NULL, NULL, "fsl,qe-ic");
if (!np) {
np = of_find_node_by_type(NULL, "qeic");
if (!np)
return;
}
qe_ic_init(np, 0, qe_ic_cascade_low_ipic, qe_ic_cascade_high_ipic);
of_node_put(np);
}
void __init mpc83xx_ipic_and_qe_init_IRQ(void)
{
mpc83xx_ipic_init_IRQ();
mpc83xx_qe_init_IRQ();
}
#endif /* CONFIG_QUICC_ENGINE */
static const struct of_device_id of_bus_ids[] __initconst = {
{ .type = "soc", },
{ .compatible = "soc", },
{ .compatible = "simple-bus" },
{ .compatible = "gianfar" },
{ .compatible = "gpio-leds", },
{ .type = "qe", },
{ .compatible = "fsl,qe", },
{},
};
int __init mpc83xx_declare_of_platform_devices(void)
{
of_platform_bus_probe(NULL, of_bus_ids, NULL);
return 0;
}
#ifdef CONFIG_PCI
void __init mpc83xx_setup_pci(void)
{
struct device_node *np;
for_each_compatible_node(np, "pci", "fsl,mpc8349-pci")
mpc83xx_add_bridge(np);
for_each_compatible_node(np, "pci", "fsl,mpc8314-pcie")
mpc83xx_add_bridge(np);
}
#endif
void __init mpc83xx_setup_arch(void)
{
if (ppc_md.progress)
ppc_md.progress("mpc83xx_setup_arch()", 0);
mpc83xx_setup_pci();
}
int machine_check_83xx(struct pt_regs *regs)
{
u32 mask = 1 << (31 - IPIC_MCP_WDT);
if (!(regs->msr & SRR1_MCE_MCP) || !(ipic_get_mcp_status() & mask))
return machine_check_generic(regs);
ipic_clear_mcp_status(mask);
if (debugger_fault_handler(regs))
return 1;
die("Watchdog NMI Reset", regs, 0);
return 1;
}