/*
* ras.c
* Copyright (C) 2001 Dave Engebretsen IBM Corporation
*
* 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.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/* Change Activity:
* 2001/09/21 : engebret : Created with minimal EPOW and HW exception support.
* End Change Activity
*/
#include <linux/errno.h>
#include <linux/threads.h>
#include <linux/kernel_stat.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/timex.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/random.h>
#include <linux/sysrq.h>
#include <linux/bitops.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/irq.h>
#include <asm/cache.h>
#include <asm/prom.h>
#include <asm/ptrace.h>
#include <asm/machdep.h>
#include <asm/rtas.h>
#include <asm/ppcdebug.h>
static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX];
static DEFINE_SPINLOCK(ras_log_buf_lock);
char mce_data_buf[RTAS_ERROR_LOG_MAX]
;
/* This is true if we are using the firmware NMI handler (typically LPAR) */
extern int fwnmi_active;
static int ras_get_sensor_state_token;
static int ras_check_exception_token;
#define EPOW_SENSOR_TOKEN 9
#define EPOW_SENSOR_INDEX 0
#define RAS_VECTOR_OFFSET 0x500
static irqreturn_t ras_epow_interrupt(int irq, void *dev_id,
struct pt_regs * regs);
static irqreturn_t ras_error_interrupt(int irq, void *dev_id,
struct pt_regs * regs);
/* #define DEBUG */
static void request_ras_irqs(struct device_node *np, char *propname,
irqreturn_t (*handler)(int, void *, struct pt_regs *),
const char *name)
{
unsigned int *ireg, len, i;
int virq, n_intr;
ireg = (unsigned int *)get_property(np, propname, &len);
if (ireg == NULL)
return;
n_intr = prom_n_intr_cells(np);
len /= n_intr * sizeof(*ireg);
for (i = 0; i < len; i++) {
virq = virt_irq_create_mapping(*ireg);
if (virq == NO_IRQ) {
printk(KERN_ERR "Unable to allocate interrupt "
"number for %s\n", np->full_name);
return;
}
if (request_irq(irq_offset_up(virq), handler, 0, name, NULL)) {
printk(KERN_ERR "Unable to request interrupt %d for "
"%s\n", irq_offset_up(virq), np->full_name);
return;
}
ireg += n_intr;
}
}
/*
* Initialize handlers for the set of interrupts caused by hardware errors
* and power system events.
*/
static int __init init_ras_IRQ(void)
{
struct device_node *np;
ras_get_sensor_state_token = rtas_token("get-sensor-state");
ras_check_exception_token = rtas_token("check-exception");
/* Internal Errors */
np = of_find_node_by_path("/event-sources/internal-errors");
if (np != NULL) {
request_ras_irqs(np, "open-pic-interrupt", ras_error_interrupt,
"RAS_ERROR");
request_ras_irqs(np, "interrupts", ras_error_interrupt,
"RAS_ERROR");
of_node_put(np);
}
/* EPOW Events */
np = of_find_node_by_path("/event-sources/epow-events");
if (np != NULL) {
request_ras_irqs(np, "open-pic-interrupt", ras_epow_interrupt,
"RAS_EPOW");
request_ras_irqs(np, "interrupts", ras_epow_interrupt,
"RAS_EPOW");
of_node_put(np);
}
return 1;
}
__initcall(init_ras_IRQ);
/*
* Handle power subsystem events (EPOW).
*
* Presently we just log the event has occurred. This should be fixed
* to examine the type of power failure and take appropriate action where
* the time horizon permits something useful to be done.
*/
static irqreturn_t
ras_epow_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
int status = 0xdeadbeef;
int state = 0;
int critical;
status = rtas_call(ras_get_sensor_state_token, 2, 2, &state,
EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX);
if (state > 3)
critical = 1; /* Time Critical */
else
critical = 0;
spin_lock(&ras_log_buf_lock);
status = rtas_call(ras_check_exception_token, 6, 1, NULL,
RAS_VECTOR_OFFSET,
virt_irq_to_real(irq_offset_down(irq)),
RTAS_EPOW_WARNING | RTAS_POWERMGM_EVENTS,
critical, __pa(&ras_log_buf),
rtas_get_error_log_max());
udbg_printf("EPOW <0x%lx 0x%x 0x%x>\n",
*((unsigned long *)&ras_log_buf), status, state);
printk(KERN_WARNING "EPOW <0x%lx 0x%x 0x%x>\n",
*((unsigned long *)&ras_log_buf), status, state);
/* format and print the extended information */
log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
spin_unlock(&ras_log_buf_lock);
return IRQ_HANDLED;
}
/*
* Handle hardware error interrupts.
*
* RTAS check-exception is called to collect data on the exception. If
* the error is deemed recoverable, we log a warning and return.
* For nonrecoverable errors, an error is logged and we stop all processing
* as quickly as possible in order to prevent propagation of the failure.
*/
static irqreturn_t
ras_error_interrupt(int irq, void *dev_id, struct pt_regs * regs)
{
struct rtas_error_log *rtas_elog;
int status = 0xdeadbeef;
int fatal;
spin_lock(&ras_log_buf_lock);
status = rtas_call(ras_check_exception_token, 6, 1, NULL,
RAS_VECTOR_OFFSET,
virt_irq_to_real(irq_offset_down(irq)),
RTAS_INTERNAL_ERROR, 1 /*Time Critical */,
__pa(&ras_log_buf),
rtas_get_error_log_max());
rtas_elog = (struct rtas_error_log *)ras_log_buf;
if ((status == 0) && (rtas_elog->severity >= RTAS_SEVERITY_ERROR_SYNC))
fatal = 1;
else
fatal = 0;
/* format and print the extended information */
log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);
if (fatal) {
udbg_printf("Fatal HW Error <0x%lx 0x%x>\n",
*((unsigned long *)&ras_log_buf), status);
printk(KERN_EMERG "Error: Fatal hardware error <0x%lx 0x%x>\n",
*((unsigned long *)&ras_log_buf), status);
#ifndef DEBUG
/* Don't actually power off when debugging so we can test
* without actually failing while injecting errors.
* Error data will not be logged to syslog.
*/
ppc_md.power_off();
#endif
} else {
udbg_printf("Recoverable HW Error <0x%lx 0x%x>\n",
*((unsigned long *)&ras_log_buf), status);
printk(KERN_WARNING
"Warning: Recoverable hardware error <0x%lx 0x%x>\n",
*((unsigned long *)&ras_log_buf), status);
}
spin_unlock(&ras_log_buf_lock);
return IRQ_HANDLED;
}
/* Get the error information for errors coming through the
* FWNMI vectors. The pt_regs' r3 will be updated to reflect
* the actual r3 if possible, and a ptr to the error log entry
* will be returned if found.
*
* The mce_data_buf does not have any locks or protection around it,
* if a second machine check comes in, or a system reset is done
* before we have logged the error, then we will get corruption in the
* error log. This is preferable over holding off on calling
* ibm,nmi-interlock which would result in us checkstopping if a
* second machine check did come in.
*/
static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
{
unsigned long errdata = regs->gpr[3];
struct rtas_error_log *errhdr = NULL;
unsigned long *savep;
if ((errdata >= 0x7000 && errdata < 0x7fff0) ||
(errdata >= rtas.base && errdata < rtas.base + rtas.size - 16)) {
savep = __va(errdata);
regs->gpr[3] = savep[0]; /* restore original r3 */
memset(mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
memcpy(mce_data_buf, (char *)(savep + 1), RTAS_ERROR_LOG_MAX);
errhdr = (struct rtas_error_log *)mce_data_buf;
} else {
printk("FWNMI: corrupt r3\n");
}
return errhdr;
}
/* Call this when done with the data returned by FWNMI_get_errinfo.
* It will release the saved data area for other CPUs in the
* partition to receive FWNMI errors.
*/
static void fwnmi_release_errinfo(void)
{
int ret = rtas_call(rtas_token("ibm,nmi-interlock"), 0, 1, NULL);
if (ret != 0)
printk("FWNMI: nmi-interlock failed: %d\n", ret);
}
void pSeries_system_reset_exception(struct pt_regs *regs)
{
if (fwnmi_active) {
struct rtas_error_log *errhdr = fwnmi_get_errinfo(regs);
if (errhdr) {
/* XXX Should look at FWNMI information */
}
fwnmi_release_errinfo();
}
}
/*
* See if we can recover from a machine check exception.
* This is only called on power4 (or above) and only via
* the Firmware Non-Maskable Interrupts (fwnmi) handler
* which provides the error analysis for us.
*
* Return 1 if corrected (or delivered a signal).
* Return 0 if there is nothing we can do.
*/
static int recover_mce(struct pt_regs *regs, struct rtas_error_log * err)
{
int nonfatal = 0;
if (err->disposition == RTAS_DISP_FULLY_RECOVERED) {
/* Platform corrected itself */
nonfatal = 1;
} else if ((regs->msr & MSR_RI) &&
user_mode(regs) &&
err->severity == RTAS_SEVERITY_ERROR_SYNC &&
err->disposition == RTAS_DISP_NOT_RECOVERED &&
err->target == RTAS_TARGET_MEMORY &&
err->type == RTAS_TYPE_ECC_UNCORR &&
!(current->pid == 0 || current->pid == 1)) {
/* Kill off a user process with an ECC error */
printk(KERN_ERR "MCE: uncorrectable ecc error for pid %d\n",
current->pid);
/* XXX something better for ECC error? */
_exception(SIGBUS, regs, BUS_ADRERR, regs->nip);
nonfatal = 1;
}
log_error((char *)err, ERR_TYPE_RTAS_LOG, !nonfatal);
return nonfatal;
}
/*
* Handle a machine check.
*
* Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi)
* should be present. If so the handler which called us tells us if the
* error was recovered (never true if RI=0).
*
* On hardware prior to Power 4 these exceptions were asynchronous which
* means we can't tell exactly where it occurred and so we can't recover.
*/
int pSeries_machine_check_exception(struct pt_regs *regs)
{
struct rtas_error_log *errp;
if (fwnmi_active) {
errp = fwnmi_get_errinfo(regs);
fwnmi_release_errinfo();
if (errp && recover_mce(regs, errp))
return 1;
}
return 0;
}
