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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ds1620.c
/*
* linux/drivers/char/ds1620.c: Dallas Semiconductors DS1620
* thermometer driver (as used in the Rebel.com NetWinder)
*/
#include <linux/module.h>
#include <linux/miscdevice.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/capability.h>
#include <linux/init.h>
#include <linux/smp_lock.h>
#include <mach/hardware.h>
#include <asm/mach-types.h>
#include <asm/uaccess.h>
#include <asm/therm.h>
#ifdef CONFIG_PROC_FS
/* define for /proc interface */
#define THERM_USE_PROC
#endif
/* Definitions for DS1620 chip */
#define THERM_START_CONVERT 0xee
#define THERM_RESET 0xaf
#define THERM_READ_CONFIG 0xac
#define THERM_READ_TEMP 0xaa
#define THERM_READ_TL 0xa2
#define THERM_READ_TH 0xa1
#define THERM_WRITE_CONFIG 0x0c
#define THERM_WRITE_TL 0x02
#define THERM_WRITE_TH 0x01
#define CFG_CPU 2
#define CFG_1SHOT 1
static const char *fan_state[] = { "off", "on", "on (hardwired)" };
/*
* Start of NetWinder specifics
* Note! We have to hold the gpio lock with IRQs disabled over the
* whole of our transaction to the Dallas chip, since there is a
* chance that the WaveArtist driver could touch these bits to
* enable or disable the speaker.
*/
extern unsigned int system_rev;
static inline void netwinder_ds1620_set_clk(int clk)
{
nw_gpio_modify_op(GPIO_DSCLK, clk ? GPIO_DSCLK : 0);
}
static inline void netwinder_ds1620_set_data(int dat)
{
nw_gpio_modify_op(GPIO_DATA, dat ? GPIO_DATA : 0);
}
static inline int netwinder_ds1620_get_data(void)
{
return nw_gpio_read() & GPIO_DATA;
}
static inline void netwinder_ds1620_set_data_dir(int dir)
{
nw_gpio_modify_io(GPIO_DATA, dir ? GPIO_DATA : 0);
}
static inline void netwinder_ds1620_reset(void)
{
nw_cpld_modify(CPLD_DS_ENABLE, 0);
nw_cpld_modify(CPLD_DS_ENABLE, CPLD_DS_ENABLE);
}
static inline void netwinder_lock(unsigned long *flags)
{
spin_lock_irqsave(&nw_gpio_lock, *flags);
}
static inline void netwinder_unlock(unsigned long *flags)
{
spin_unlock_irqrestore(&nw_gpio_lock, *flags);
}
static inline void netwinder_set_fan(int i)
{
unsigned long flags;
spin_lock_irqsave(&nw_gpio_lock, flags);
nw_gpio_modify_op(GPIO_FAN, i ? GPIO_FAN : 0);
spin_unlock_irqrestore(&nw_gpio_lock, flags);
}
static inline int netwinder_get_fan(void)
{
if ((system_rev & 0xf000) == 0x4000)
return FAN_ALWAYS_ON;
return (nw_gpio_read() & GPIO_FAN) ? FAN_ON : FAN_OFF;
}
/*
* End of NetWinder specifics
*/
static void ds1620_send_bits(int nr, int value)
{
int i;
for (i = 0; i < nr; i++) {
netwinder_ds1620_set_data(value & 1);
netwinder_ds1620_set_clk(0);
udelay(1);
netwinder_ds1620_set_clk(1);
udelay(1);
value >>= 1;
}
}
static unsigned int ds1620_recv_bits(int nr)
{
unsigned int value = 0, mask = 1;
int i;
netwinder_ds1620_set_data(0);
for (i = 0; i < nr; i++) {
netwinder_ds1620_set_clk(0);
udelay(1);
if (netwinder_ds1620_get_data())
value |= mask;
mask <<= 1;
netwinder_ds1620_set_clk(1);
udelay(1);
}
return value;
}
static void ds1620_out(int cmd, int bits, int value)
{
unsigned long flags;
netwinder_lock(&flags);
netwinder_ds1620_set_clk(1);
netwinder_ds1620_set_data_dir(0);
netwinder_ds1620_reset();
udelay(1);
ds1620_send_bits(8, cmd);
if (bits)
ds1620_send_bits(bits, value);
udelay(1);
netwinder_ds1620_reset();
netwinder_unlock(&flags);
msleep(20);
}
static unsigned int ds1620_in(int cmd, int bits)
{
unsigned long flags;
unsigned int value;
netwinder_lock(&flags);
netwinder_ds1620_set_clk(1);
netwinder_ds1620_set_data_dir(0);
netwinder_ds1620_reset();
udelay(1);
ds1620_send_bits(8, cmd);
netwinder_ds1620_set_data_dir(1);
value = ds1620_recv_bits(bits);
netwinder_ds1620_reset();
netwinder_unlock(&flags);
return value;
}
static int cvt_9_to_int(unsigned int val)
{
if (val & 0x100)
val |= 0xfffffe00;
return val;
}
static void ds1620_write_state(struct therm *therm)
{
ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU);
ds1620_out(THERM_WRITE_TL, 9, therm->lo);
ds1620_out(THERM_WRITE_TH, 9, therm->hi);
ds1620_out(THERM_START_CONVERT, 0, 0);
}
static void ds1620_read_state(struct therm *therm)
{
therm->lo = cvt_9_to_int(ds1620_in(THERM_READ_TL, 9));
therm->hi = cvt_9_to_int(ds1620_in(THERM_READ_TH, 9));
}
static int ds1620_open(struct inode *inode, struct file *file)
{
cycle_kernel_lock();
return nonseekable_open(inode, file);
}
static ssize_t
ds1620_read(struct file *file, char __user *buf, size_t count, loff_t *ptr)
{
signed int cur_temp;
signed char cur_temp_degF;
cur_temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9)) >> 1;
/* convert to Fahrenheit, as per wdt.c */
cur_temp_degF = (cur_temp * 9) / 5 + 32;
if (copy_to_user(buf, &cur_temp_degF, 1))
return -EFAULT;
return 1;
}
static int
ds1620_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
{
struct therm therm;
union {
struct therm __user *therm;
int __user *i;
} uarg;
int i;
uarg.i = (int __user *)arg;
switch(cmd) {
case CMD_SET_THERMOSTATE:
case CMD_SET_THERMOSTATE2:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (cmd == CMD_SET_THERMOSTATE) {
if (get_user(therm.hi, uarg.i))
return -EFAULT;
therm.lo = therm.hi - 3;
} else {
if (copy_from_user(&therm, uarg.therm, sizeof(therm)))
return -EFAULT;
}
therm.lo <<= 1;
therm.hi <<= 1;
ds1620_write_state(&therm);
break;
case CMD_GET_THERMOSTATE:
case CMD_GET_THERMOSTATE2:
ds1620_read_state(&therm);
therm.lo >>= 1;
therm.hi >>= 1;
if (cmd == CMD_GET_THERMOSTATE) {
if (put_user(therm.hi, uarg.i))
return -EFAULT;
} else {
if (copy_to_user(uarg.therm, &therm, sizeof(therm)))
return -EFAULT;
}
break;
case CMD_GET_TEMPERATURE:
case CMD_GET_TEMPERATURE2:
i = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
if (cmd == CMD_GET_TEMPERATURE)
i >>= 1;
return put_user(i, uarg.i) ? -EFAULT : 0;
case CMD_GET_STATUS:
i = ds1620_in(THERM_READ_CONFIG, 8) & 0xe3;
return put_user(i, uarg.i) ? -EFAULT : 0;
case CMD_GET_FAN:
i = netwinder_get_fan();
return put_user(i, uarg.i) ? -EFAULT : 0;
case CMD_SET_FAN:
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
if (get_user(i, uarg.i))
return -EFAULT;
netwinder_set_fan(i);
break;
default:
return -ENOIOCTLCMD;
}
return 0;
}
#ifdef THERM_USE_PROC
static int
proc_therm_ds1620_read(char *buf, char **start, off_t offset,
int len, int *eof, void *unused)
{
struct therm th;
int temp;
ds1620_read_state(&th);
temp = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
len = sprintf(buf, "Thermostat: HI %i.%i, LOW %i.%i; "
"temperature: %i.%i C, fan %s\n",
th.hi >> 1, th.hi & 1 ? 5 : 0,
th.lo >> 1, th.lo & 1 ? 5 : 0,
temp >> 1, temp & 1 ? 5 : 0,
fan_state[netwinder_get_fan()]);
return len;
}
static struct proc_dir_entry *proc_therm_ds1620;
#endif
static const struct file_operations ds1620_fops = {
.owner = THIS_MODULE,
.open = ds1620_open,
.read = ds1620_read,
.ioctl = ds1620_ioctl,
};
static struct miscdevice ds1620_miscdev = {
TEMP_MINOR,
"temp",
&ds1620_fops
};
static int __init ds1620_init(void)
{
int ret;
struct therm th, th_start;
if (!machine_is_netwinder())
return -ENODEV;
ds1620_out(THERM_RESET, 0, 0);
ds1620_out(THERM_WRITE_CONFIG, 8, CFG_CPU);
ds1620_out(THERM_START_CONVERT, 0, 0);
/*
* Trigger the fan to start by setting
* temperature high point low. This kicks
* the fan into action.
*/
ds1620_read_state(&th);
th_start.lo = 0;
th_start.hi = 1;
ds1620_write_state(&th_start);
msleep(2000);
ds1620_write_state(&th);
ret = misc_register(&ds1620_miscdev);
if (ret < 0)
return ret;
#ifdef THERM_USE_PROC
proc_therm_ds1620 = create_proc_entry("therm", 0, NULL);
if (proc_therm_ds1620)
proc_therm_ds1620->read_proc = proc_therm_ds1620_read;
else
printk(KERN_ERR "therm: unable to register /proc/therm\n");
#endif
ds1620_read_state(&th);
ret = cvt_9_to_int(ds1620_in(THERM_READ_TEMP, 9));
printk(KERN_INFO "Thermostat: high %i.%i, low %i.%i, "
"current %i.%i C, fan %s.\n",
th.hi >> 1, th.hi & 1 ? 5 : 0,
th.lo >> 1, th.lo & 1 ? 5 : 0,
ret >> 1, ret & 1 ? 5 : 0,
fan_state[netwinder_get_fan()]);
return 0;
}
static void __exit ds1620_exit(void)
{
#ifdef THERM_USE_PROC
remove_proc_entry("therm", NULL);
#endif
misc_deregister(&ds1620_miscdev);
}
module_init(ds1620_init);
module_exit(ds1620_exit);
MODULE_LICENSE("GPL");
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