Revision 475049809977bf3975d78f2d2fd992e19ce2d59e authored by Roel Kluin on 10 March 2009, 19:55:45 UTC, committed by Linus Torvalds on 10 March 2009, 22:55:10 UTC
get_nid_for_pfn() returns int Presumably the (nid < 0) case has never happened. We do know that it is happening on one system while creating a symlink for a memory section so it should also happen on the same system if unregister_mem_sect_under_nodes() were called to remove the same symlink. The test was actually added in response to a problem with an earlier version reported by Yasunori Goto where one or more of the leading pages of a memory section on the 2nd node of one of his systems was uninitialized because I believe they coincided with a memory hole. That earlier version did not ignore uninitialized pages and determined the nid by considering only the 1st page of each memory section. This caused the symlink to the 1st memory section on the 2nd node to be incorrectly created in /sys/devices/system/node/node0 instead of /sys/devices/system/node/node1. The problem was fixed by adding the test to skip over uninitialized pages. I suspect we have not seen any reports of the non-removal of a symlink due to the incorrect declaration of the nid variable in unregister_mem_sect_under_nodes() because - systems where a memory section could have an uninitialized range of leading pages are probably rare. - memory remove is probably not done very frequently on the systems that are capable of demonstrating the problem. - lingering symlink(s) that should have been removed may have simply gone unnoticed. [garyhade@us.ibm.com: wrote changelog] Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Cc: Gary Hade <garyhade@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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snsc_event.c
/*
* SN Platform system controller communication support
*
* 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.
*
* Copyright (C) 2004-2006 Silicon Graphics, Inc. All rights reserved.
*/
/*
* System controller event handler
*
* These routines deal with environmental events arriving from the
* system controllers.
*/
#include <linux/interrupt.h>
#include <linux/sched.h>
#include <asm/byteorder.h>
#include <asm/sn/sn_sal.h>
#include <asm/unaligned.h>
#include "snsc.h"
static struct subch_data_s *event_sd;
void scdrv_event(unsigned long);
DECLARE_TASKLET(sn_sysctl_event, scdrv_event, 0);
/*
* scdrv_event_interrupt
*
* Pull incoming environmental events off the physical link to the
* system controller and put them in a temporary holding area in SAL.
* Schedule scdrv_event() to move them along to their ultimate
* destination.
*/
static irqreturn_t
scdrv_event_interrupt(int irq, void *subch_data)
{
struct subch_data_s *sd = subch_data;
unsigned long flags;
int status;
spin_lock_irqsave(&sd->sd_rlock, flags);
status = ia64_sn_irtr_intr(sd->sd_nasid, sd->sd_subch);
if ((status > 0) && (status & SAL_IROUTER_INTR_RECV)) {
tasklet_schedule(&sn_sysctl_event);
}
spin_unlock_irqrestore(&sd->sd_rlock, flags);
return IRQ_HANDLED;
}
/*
* scdrv_parse_event
*
* Break an event (as read from SAL) into useful pieces so we can decide
* what to do with it.
*/
static int
scdrv_parse_event(char *event, int *src, int *code, int *esp_code, char *desc)
{
char *desc_end;
/* record event source address */
*src = get_unaligned_be32(event);
event += 4; /* move on to event code */
/* record the system controller's event code */
*code = get_unaligned_be32(event);
event += 4; /* move on to event arguments */
/* how many arguments are in the packet? */
if (*event++ != 2) {
/* if not 2, give up */
return -1;
}
/* parse out the ESP code */
if (*event++ != IR_ARG_INT) {
/* not an integer argument, so give up */
return -1;
}
*esp_code = get_unaligned_be32(event);
event += 4;
/* parse out the event description */
if (*event++ != IR_ARG_ASCII) {
/* not an ASCII string, so give up */
return -1;
}
event[CHUNKSIZE-1] = '\0'; /* ensure this string ends! */
event += 2; /* skip leading CR/LF */
desc_end = desc + sprintf(desc, "%s", event);
/* strip trailing CR/LF (if any) */
for (desc_end--;
(desc_end != desc) && ((*desc_end == 0xd) || (*desc_end == 0xa));
desc_end--) {
*desc_end = '\0';
}
return 0;
}
/*
* scdrv_event_severity
*
* Figure out how urgent a message we should write to the console/syslog
* via printk.
*/
static char *
scdrv_event_severity(int code)
{
int ev_class = (code & EV_CLASS_MASK);
int ev_severity = (code & EV_SEVERITY_MASK);
char *pk_severity = KERN_NOTICE;
switch (ev_class) {
case EV_CLASS_POWER:
switch (ev_severity) {
case EV_SEVERITY_POWER_LOW_WARNING:
case EV_SEVERITY_POWER_HIGH_WARNING:
pk_severity = KERN_WARNING;
break;
case EV_SEVERITY_POWER_HIGH_FAULT:
case EV_SEVERITY_POWER_LOW_FAULT:
pk_severity = KERN_ALERT;
break;
}
break;
case EV_CLASS_FAN:
switch (ev_severity) {
case EV_SEVERITY_FAN_WARNING:
pk_severity = KERN_WARNING;
break;
case EV_SEVERITY_FAN_FAULT:
pk_severity = KERN_CRIT;
break;
}
break;
case EV_CLASS_TEMP:
switch (ev_severity) {
case EV_SEVERITY_TEMP_ADVISORY:
pk_severity = KERN_WARNING;
break;
case EV_SEVERITY_TEMP_CRITICAL:
pk_severity = KERN_CRIT;
break;
case EV_SEVERITY_TEMP_FAULT:
pk_severity = KERN_ALERT;
break;
}
break;
case EV_CLASS_ENV:
pk_severity = KERN_ALERT;
break;
case EV_CLASS_TEST_FAULT:
pk_severity = KERN_ALERT;
break;
case EV_CLASS_TEST_WARNING:
pk_severity = KERN_WARNING;
break;
case EV_CLASS_PWRD_NOTIFY:
pk_severity = KERN_ALERT;
break;
}
return pk_severity;
}
/*
* scdrv_dispatch_event
*
* Do the right thing with an incoming event. That's often nothing
* more than printing it to the system log. For power-down notifications
* we start a graceful shutdown.
*/
static void
scdrv_dispatch_event(char *event, int len)
{
static int snsc_shutting_down = 0;
int code, esp_code, src, class;
char desc[CHUNKSIZE];
char *severity;
if (scdrv_parse_event(event, &src, &code, &esp_code, desc) < 0) {
/* ignore uninterpretible event */
return;
}
/* how urgent is the message? */
severity = scdrv_event_severity(code);
class = (code & EV_CLASS_MASK);
if (class == EV_CLASS_PWRD_NOTIFY || code == ENV_PWRDN_PEND) {
if (snsc_shutting_down)
return;
snsc_shutting_down = 1;
/* give a message for each type of event */
if (class == EV_CLASS_PWRD_NOTIFY)
printk(KERN_NOTICE "Power off indication received."
" Sending SIGPWR to init...\n");
else if (code == ENV_PWRDN_PEND)
printk(KERN_CRIT "WARNING: Shutting down the system"
" due to a critical environmental condition."
" Sending SIGPWR to init...\n");
/* give a SIGPWR signal to init proc */
kill_cad_pid(SIGPWR, 0);
} else {
/* print to system log */
printk("%s|$(0x%x)%s\n", severity, esp_code, desc);
}
}
/*
* scdrv_event
*
* Called as a tasklet when an event arrives from the L1. Read the event
* from where it's temporarily stored in SAL and call scdrv_dispatch_event()
* to send it on its way. Keep trying to read events until SAL indicates
* that there are no more immediately available.
*/
void
scdrv_event(unsigned long dummy)
{
int status;
int len;
unsigned long flags;
struct subch_data_s *sd = event_sd;
/* anything to read? */
len = CHUNKSIZE;
spin_lock_irqsave(&sd->sd_rlock, flags);
status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
sd->sd_rb, &len);
while (!(status < 0)) {
spin_unlock_irqrestore(&sd->sd_rlock, flags);
scdrv_dispatch_event(sd->sd_rb, len);
len = CHUNKSIZE;
spin_lock_irqsave(&sd->sd_rlock, flags);
status = ia64_sn_irtr_recv(sd->sd_nasid, sd->sd_subch,
sd->sd_rb, &len);
}
spin_unlock_irqrestore(&sd->sd_rlock, flags);
}
/*
* scdrv_event_init
*
* Sets up a system controller subchannel to begin receiving event
* messages. This is sort of a specialized version of scdrv_open()
* in drivers/char/sn_sysctl.c.
*/
void
scdrv_event_init(struct sysctl_data_s *scd)
{
int rv;
event_sd = kzalloc(sizeof (struct subch_data_s), GFP_KERNEL);
if (event_sd == NULL) {
printk(KERN_WARNING "%s: couldn't allocate subchannel info"
" for event monitoring\n", __func__);
return;
}
/* initialize subch_data_s fields */
event_sd->sd_nasid = scd->scd_nasid;
spin_lock_init(&event_sd->sd_rlock);
/* ask the system controllers to send events to this node */
event_sd->sd_subch = ia64_sn_sysctl_event_init(scd->scd_nasid);
if (event_sd->sd_subch < 0) {
kfree(event_sd);
printk(KERN_WARNING "%s: couldn't open event subchannel\n",
__func__);
return;
}
/* hook event subchannel up to the system controller interrupt */
rv = request_irq(SGI_UART_VECTOR, scdrv_event_interrupt,
IRQF_SHARED | IRQF_DISABLED,
"system controller events", event_sd);
if (rv) {
printk(KERN_WARNING "%s: irq request failed (%d)\n",
__func__, rv);
ia64_sn_irtr_close(event_sd->sd_nasid, event_sd->sd_subch);
kfree(event_sd);
return;
}
}
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