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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ds1302.c
/*!***************************************************************************
*!
*! FILE NAME : ds1302.c
*!
*! DESCRIPTION: Implements an interface for the DS1302 RTC
*!
*! Functions exported: ds1302_readreg, ds1302_writereg, ds1302_init, get_rtc_status
*!
*! ---------------------------------------------------------------------------
*!
*! (C) Copyright 1999, 2000, 2001 Axis Communications AB, LUND, SWEDEN
*!
*!***************************************************************************/
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/bcd.h>
#include <linux/smp_lock.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <asm/system.h>
#include <asm/rtc.h>
#if defined(CONFIG_M32R)
#include <asm/m32r.h>
#endif
#define RTC_MAJOR_NR 121 /* local major, change later */
static const char ds1302_name[] = "ds1302";
/* Send 8 bits. */
static void
out_byte_rtc(unsigned int reg_addr, unsigned char x)
{
//RST H
outw(0x0001,(unsigned long)PLD_RTCRSTODT);
//write data
outw(((x<<8)|(reg_addr&0xff)),(unsigned long)PLD_RTCWRDATA);
//WE
outw(0x0002,(unsigned long)PLD_RTCCR);
//wait
while(inw((unsigned long)PLD_RTCCR));
//RST L
outw(0x0000,(unsigned long)PLD_RTCRSTODT);
}
static unsigned char
in_byte_rtc(unsigned int reg_addr)
{
unsigned char retval;
//RST H
outw(0x0001,(unsigned long)PLD_RTCRSTODT);
//write data
outw((reg_addr&0xff),(unsigned long)PLD_RTCRDDATA);
//RE
outw(0x0001,(unsigned long)PLD_RTCCR);
//wait
while(inw((unsigned long)PLD_RTCCR));
//read data
retval=(inw((unsigned long)PLD_RTCRDDATA) & 0xff00)>>8;
//RST L
outw(0x0000,(unsigned long)PLD_RTCRSTODT);
return retval;
}
/* Enable writing. */
static void
ds1302_wenable(void)
{
out_byte_rtc(0x8e,0x00);
}
/* Disable writing. */
static void
ds1302_wdisable(void)
{
out_byte_rtc(0x8e,0x80);
}
/* Read a byte from the selected register in the DS1302. */
unsigned char
ds1302_readreg(int reg)
{
unsigned char x;
x=in_byte_rtc((0x81 | (reg << 1))); /* read register */
return x;
}
/* Write a byte to the selected register. */
void
ds1302_writereg(int reg, unsigned char val)
{
ds1302_wenable();
out_byte_rtc((0x80 | (reg << 1)),val);
ds1302_wdisable();
}
void
get_rtc_time(struct rtc_time *rtc_tm)
{
unsigned long flags;
local_irq_save(flags);
rtc_tm->tm_sec = CMOS_READ(RTC_SECONDS);
rtc_tm->tm_min = CMOS_READ(RTC_MINUTES);
rtc_tm->tm_hour = CMOS_READ(RTC_HOURS);
rtc_tm->tm_mday = CMOS_READ(RTC_DAY_OF_MONTH);
rtc_tm->tm_mon = CMOS_READ(RTC_MONTH);
rtc_tm->tm_year = CMOS_READ(RTC_YEAR);
local_irq_restore(flags);
rtc_tm->tm_sec = bcd2bin(rtc_tm->tm_sec);
rtc_tm->tm_min = bcd2bin(rtc_tm->tm_min);
rtc_tm->tm_hour = bcd2bin(rtc_tm->tm_hour);
rtc_tm->tm_mday = bcd2bin(rtc_tm->tm_mday);
rtc_tm->tm_mon = bcd2bin(rtc_tm->tm_mon);
rtc_tm->tm_year = bcd2bin(rtc_tm->tm_year);
/*
* Account for differences between how the RTC uses the values
* and how they are defined in a struct rtc_time;
*/
if (rtc_tm->tm_year <= 69)
rtc_tm->tm_year += 100;
rtc_tm->tm_mon--;
}
static unsigned char days_in_mo[] =
{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
/* ioctl that supports RTC_RD_TIME and RTC_SET_TIME (read and set time/date). */
static long rtc_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
unsigned long flags;
switch(cmd) {
case RTC_RD_TIME: /* read the time/date from RTC */
{
struct rtc_time rtc_tm;
memset(&rtc_tm, 0, sizeof (struct rtc_time));
lock_kernel();
get_rtc_time(&rtc_tm);
unlock_kernel();
if (copy_to_user((struct rtc_time*)arg, &rtc_tm, sizeof(struct rtc_time)))
return -EFAULT;
return 0;
}
case RTC_SET_TIME: /* set the RTC */
{
struct rtc_time rtc_tm;
unsigned char mon, day, hrs, min, sec, leap_yr;
unsigned int yrs;
if (!capable(CAP_SYS_TIME))
return -EPERM;
if (copy_from_user(&rtc_tm, (struct rtc_time*)arg, sizeof(struct rtc_time)))
return -EFAULT;
yrs = rtc_tm.tm_year + 1900;
mon = rtc_tm.tm_mon + 1; /* tm_mon starts at zero */
day = rtc_tm.tm_mday;
hrs = rtc_tm.tm_hour;
min = rtc_tm.tm_min;
sec = rtc_tm.tm_sec;
if ((yrs < 1970) || (yrs > 2069))
return -EINVAL;
leap_yr = ((!(yrs % 4) && (yrs % 100)) || !(yrs % 400));
if ((mon > 12) || (day == 0))
return -EINVAL;
if (day > (days_in_mo[mon] + ((mon == 2) && leap_yr)))
return -EINVAL;
if ((hrs >= 24) || (min >= 60) || (sec >= 60))
return -EINVAL;
if (yrs >= 2000)
yrs -= 2000; /* RTC (0, 1, ... 69) */
else
yrs -= 1900; /* RTC (70, 71, ... 99) */
sec = bin2bcd(sec);
min = bin2bcd(min);
hrs = bin2bcd(hrs);
day = bin2bcd(day);
mon = bin2bcd(mon);
yrs = bin2bcd(yrs);
lock_kernel();
local_irq_save(flags);
CMOS_WRITE(yrs, RTC_YEAR);
CMOS_WRITE(mon, RTC_MONTH);
CMOS_WRITE(day, RTC_DAY_OF_MONTH);
CMOS_WRITE(hrs, RTC_HOURS);
CMOS_WRITE(min, RTC_MINUTES);
CMOS_WRITE(sec, RTC_SECONDS);
local_irq_restore(flags);
unlock_kernel();
/* Notice that at this point, the RTC is updated but
* the kernel is still running with the old time.
* You need to set that separately with settimeofday
* or adjtimex.
*/
return 0;
}
case RTC_SET_CHARGE: /* set the RTC TRICKLE CHARGE register */
{
int tcs_val;
if (!capable(CAP_SYS_TIME))
return -EPERM;
if(copy_from_user(&tcs_val, (int*)arg, sizeof(int)))
return -EFAULT;
lock_kernel();
tcs_val = RTC_TCR_PATTERN | (tcs_val & 0x0F);
ds1302_writereg(RTC_TRICKLECHARGER, tcs_val);
unlock_kernel();
return 0;
}
default:
return -EINVAL;
}
}
int
get_rtc_status(char *buf)
{
char *p;
struct rtc_time tm;
p = buf;
get_rtc_time(&tm);
/*
* There is no way to tell if the luser has the RTC set for local
* time or for Universal Standard Time (GMT). Probably local though.
*/
p += sprintf(p,
"rtc_time\t: %02d:%02d:%02d\n"
"rtc_date\t: %04d-%02d-%02d\n",
tm.tm_hour, tm.tm_min, tm.tm_sec,
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday);
return p - buf;
}
/* The various file operations we support. */
static const struct file_operations rtc_fops = {
.owner = THIS_MODULE,
.unlocked_ioctl = rtc_ioctl,
};
/* Probe for the chip by writing something to its RAM and try reading it back. */
#define MAGIC_PATTERN 0x42
static int __init
ds1302_probe(void)
{
int retval, res, baur;
baur=(boot_cpu_data.bus_clock/(2*1000*1000));
printk("%s: Set PLD_RTCBAUR = %d\n", ds1302_name,baur);
outw(0x0000,(unsigned long)PLD_RTCCR);
outw(0x0000,(unsigned long)PLD_RTCRSTODT);
outw(baur,(unsigned long)PLD_RTCBAUR);
/* Try to talk to timekeeper. */
ds1302_wenable();
/* write RAM byte 0 */
/* write something magic */
out_byte_rtc(0xc0,MAGIC_PATTERN);
/* read RAM byte 0 */
if((res = in_byte_rtc(0xc1)) == MAGIC_PATTERN) {
char buf[100];
ds1302_wdisable();
printk("%s: RTC found.\n", ds1302_name);
get_rtc_status(buf);
printk(buf);
retval = 1;
} else {
printk("%s: RTC not found.\n", ds1302_name);
retval = 0;
}
return retval;
}
/* Just probe for the RTC and register the device to handle the ioctl needed. */
int __init
ds1302_init(void)
{
if (!ds1302_probe()) {
return -1;
}
return 0;
}
static int __init ds1302_register(void)
{
ds1302_init();
if (register_chrdev(RTC_MAJOR_NR, ds1302_name, &rtc_fops)) {
printk(KERN_INFO "%s: unable to get major %d for rtc\n",
ds1302_name, RTC_MAJOR_NR);
return -1;
}
return 0;
}
module_init(ds1302_register);
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