linux/drivers/parisc/led.c
Herbert Xu e5ed639913 [IPV4]: Replace __in_dev_get with __in_dev_get_rcu/rtnl
The following patch renames __in_dev_get() to __in_dev_get_rtnl() and
introduces __in_dev_get_rcu() to cover the second case.

1) RCU with refcnt should use in_dev_get().
2) RCU without refcnt should use __in_dev_get_rcu().
3) All others must hold RTNL and use __in_dev_get_rtnl().

There is one exception in net/ipv4/route.c which is in fact a pre-existing
race condition.  I've marked it as such so that we remember to fix it.

This patch is based on suggestions and prior work by Suzanne Wood and
Paul McKenney.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2005-10-03 14:35:55 -07:00

764 lines
20 KiB
C

/*
* Chassis LCD/LED driver for HP-PARISC workstations
*
* (c) Copyright 2000 Red Hat Software
* (c) Copyright 2000 Helge Deller <hdeller@redhat.com>
* (c) Copyright 2001-2004 Helge Deller <deller@gmx.de>
* (c) Copyright 2001 Randolph Chung <tausq@debian.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.
*
* TODO:
* - speed-up calculations with inlined assembler
* - interface to write to second row of LCD from /proc (if technically possible)
*
* Changes:
* - Audit copy_from_user in led_proc_write.
* Daniele Bellucci <bellucda@tiscali.it>
*/
#include <linux/config.h>
#include <linux/module.h>
#include <linux/stddef.h> /* for offsetof() */
#include <linux/init.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/utsname.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/in.h>
#include <linux/interrupt.h>
#include <linux/kernel_stat.h>
#include <linux/reboot.h>
#include <linux/proc_fs.h>
#include <linux/ctype.h>
#include <linux/blkdev.h>
#include <linux/rcupdate.h>
#include <asm/io.h>
#include <asm/processor.h>
#include <asm/hardware.h>
#include <asm/param.h> /* HZ */
#include <asm/led.h>
#include <asm/pdc.h>
#include <asm/uaccess.h>
/* The control of the LEDs and LCDs on PARISC-machines have to be done
completely in software. The necessary calculations are done in a tasklet
which is scheduled at every timer interrupt and since the calculations
may consume relatively much CPU-time some of the calculations can be
turned off with the following variables (controlled via procfs) */
static int led_type = -1;
static int led_heartbeat = 1;
static int led_diskio = 1;
static int led_lanrxtx = 1;
static char lcd_text[32];
static char lcd_text_default[32];
#if 0
#define DPRINTK(x) printk x
#else
#define DPRINTK(x)
#endif
struct lcd_block {
unsigned char command; /* stores the command byte */
unsigned char on; /* value for turning LED on */
unsigned char off; /* value for turning LED off */
};
/* Structure returned by PDC_RETURN_CHASSIS_INFO */
/* NOTE: we use unsigned long:16 two times, since the following member
lcd_cmd_reg_addr needs to be 64bit aligned on 64bit PA2.0-machines */
struct pdc_chassis_lcd_info_ret_block {
unsigned long model:16; /* DISPLAY_MODEL_XXXX */
unsigned long lcd_width:16; /* width of the LCD in chars (DISPLAY_MODEL_LCD only) */
unsigned long lcd_cmd_reg_addr; /* ptr to LCD cmd-register & data ptr for LED */
unsigned long lcd_data_reg_addr; /* ptr to LCD data-register (LCD only) */
unsigned int min_cmd_delay; /* delay in uS after cmd-write (LCD only) */
unsigned char reset_cmd1; /* command #1 for writing LCD string (LCD only) */
unsigned char reset_cmd2; /* command #2 for writing LCD string (LCD only) */
unsigned char act_enable; /* 0 = no activity (LCD only) */
struct lcd_block heartbeat;
struct lcd_block disk_io;
struct lcd_block lan_rcv;
struct lcd_block lan_tx;
char _pad;
};
/* LCD_CMD and LCD_DATA for KittyHawk machines */
#define KITTYHAWK_LCD_CMD F_EXTEND(0xf0190000UL) /* 64bit-ready */
#define KITTYHAWK_LCD_DATA (KITTYHAWK_LCD_CMD+1)
/* lcd_info is pre-initialized to the values needed to program KittyHawk LCD's
* HP seems to have used Sharp/Hitachi HD44780 LCDs most of the time. */
static struct pdc_chassis_lcd_info_ret_block
lcd_info __attribute__((aligned(8))) =
{
.model = DISPLAY_MODEL_LCD,
.lcd_width = 16,
.lcd_cmd_reg_addr = KITTYHAWK_LCD_CMD,
.lcd_data_reg_addr = KITTYHAWK_LCD_DATA,
.min_cmd_delay = 40,
.reset_cmd1 = 0x80,
.reset_cmd2 = 0xc0,
};
/* direct access to some of the lcd_info variables */
#define LCD_CMD_REG lcd_info.lcd_cmd_reg_addr
#define LCD_DATA_REG lcd_info.lcd_data_reg_addr
#define LED_DATA_REG lcd_info.lcd_cmd_reg_addr /* LASI & ASP only */
/* ptr to LCD/LED-specific function */
static void (*led_func_ptr) (unsigned char);
#define LED_HASLCD 1
#define LED_NOLCD 0
#ifdef CONFIG_PROC_FS
static int led_proc_read(char *page, char **start, off_t off, int count,
int *eof, void *data)
{
char *out = page;
int len;
switch ((long)data)
{
case LED_NOLCD:
out += sprintf(out, "Heartbeat: %d\n", led_heartbeat);
out += sprintf(out, "Disk IO: %d\n", led_diskio);
out += sprintf(out, "LAN Rx/Tx: %d\n", led_lanrxtx);
break;
case LED_HASLCD:
out += sprintf(out, "%s\n", lcd_text);
break;
default:
*eof = 1;
return 0;
}
len = out - page - off;
if (len < count) {
*eof = 1;
if (len <= 0) return 0;
} else {
len = count;
}
*start = page + off;
return len;
}
static int led_proc_write(struct file *file, const char *buf,
unsigned long count, void *data)
{
char *cur, lbuf[count + 1];
int d;
if (!capable(CAP_SYS_ADMIN))
return -EACCES;
memset(lbuf, 0, count + 1);
if (copy_from_user(lbuf, buf, count))
return -EFAULT;
cur = lbuf;
/* skip initial spaces */
while (*cur && isspace(*cur))
{
cur++;
}
switch ((long)data)
{
case LED_NOLCD:
d = *cur++ - '0';
if (d != 0 && d != 1) goto parse_error;
led_heartbeat = d;
if (*cur++ != ' ') goto parse_error;
d = *cur++ - '0';
if (d != 0 && d != 1) goto parse_error;
led_diskio = d;
if (*cur++ != ' ') goto parse_error;
d = *cur++ - '0';
if (d != 0 && d != 1) goto parse_error;
led_lanrxtx = d;
break;
case LED_HASLCD:
if (*cur && cur[strlen(cur)-1] == '\n')
cur[strlen(cur)-1] = 0;
if (*cur == 0)
cur = lcd_text_default;
lcd_print(cur);
break;
default:
return 0;
}
return count;
parse_error:
if ((long)data == LED_NOLCD)
printk(KERN_CRIT "Parse error: expect \"n n n\" (n == 0 or 1) for heartbeat,\ndisk io and lan tx/rx indicators\n");
return -EINVAL;
}
static int __init led_create_procfs(void)
{
struct proc_dir_entry *proc_pdc_root = NULL;
struct proc_dir_entry *ent;
if (led_type == -1) return -1;
proc_pdc_root = proc_mkdir("pdc", 0);
if (!proc_pdc_root) return -1;
proc_pdc_root->owner = THIS_MODULE;
ent = create_proc_entry("led", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
if (!ent) return -1;
ent->nlink = 1;
ent->data = (void *)LED_NOLCD; /* LED */
ent->read_proc = led_proc_read;
ent->write_proc = led_proc_write;
ent->owner = THIS_MODULE;
if (led_type == LED_HASLCD)
{
ent = create_proc_entry("lcd", S_IFREG|S_IRUGO|S_IWUSR, proc_pdc_root);
if (!ent) return -1;
ent->nlink = 1;
ent->data = (void *)LED_HASLCD; /* LCD */
ent->read_proc = led_proc_read;
ent->write_proc = led_proc_write;
ent->owner = THIS_MODULE;
}
return 0;
}
#endif
/*
**
** led_ASP_driver()
**
*/
#define LED_DATA 0x01 /* data to shift (0:on 1:off) */
#define LED_STROBE 0x02 /* strobe to clock data */
static void led_ASP_driver(unsigned char leds)
{
int i;
leds = ~leds;
for (i = 0; i < 8; i++) {
unsigned char value;
value = (leds & 0x80) >> 7;
gsc_writeb( value, LED_DATA_REG );
gsc_writeb( value | LED_STROBE, LED_DATA_REG );
leds <<= 1;
}
}
/*
**
** led_LASI_driver()
**
*/
static void led_LASI_driver(unsigned char leds)
{
leds = ~leds;
gsc_writeb( leds, LED_DATA_REG );
}
/*
**
** led_LCD_driver()
**
** The logic of the LCD driver is, that we write at every scheduled call
** only to one of LCD_CMD_REG _or_ LCD_DATA_REG - registers.
** That way we don't need to let this tasklet busywait for min_cmd_delay
** milliseconds.
**
** TODO: check the value of "min_cmd_delay" against the value of HZ.
**
*/
static void led_LCD_driver(unsigned char leds)
{
static int last_index; /* 0:heartbeat, 1:disk, 2:lan_in, 3:lan_out */
static int last_was_cmd;/* 0: CMD was written last, 1: DATA was last */
struct lcd_block *block_ptr;
int value;
switch (last_index) {
case 0: block_ptr = &lcd_info.heartbeat;
value = leds & LED_HEARTBEAT;
break;
case 1: block_ptr = &lcd_info.disk_io;
value = leds & LED_DISK_IO;
break;
case 2: block_ptr = &lcd_info.lan_rcv;
value = leds & LED_LAN_RCV;
break;
case 3: block_ptr = &lcd_info.lan_tx;
value = leds & LED_LAN_TX;
break;
default: /* should never happen: */
return;
}
if (last_was_cmd) {
/* write the value to the LCD data port */
gsc_writeb( value ? block_ptr->on : block_ptr->off, LCD_DATA_REG );
} else {
/* write the command-byte to the LCD command register */
gsc_writeb( block_ptr->command, LCD_CMD_REG );
}
/* now update the vars for the next interrupt iteration */
if (++last_was_cmd == 2) { /* switch between cmd & data */
last_was_cmd = 0;
if (++last_index == 4)
last_index = 0; /* switch back to heartbeat index */
}
}
/*
**
** led_get_net_activity()
**
** calculate if there was TX- or RX-troughput on the network interfaces
** (analog to dev_get_info() from net/core/dev.c)
**
*/
static __inline__ int led_get_net_activity(void)
{
#ifndef CONFIG_NET
return 0;
#else
static unsigned long rx_total_last, tx_total_last;
unsigned long rx_total, tx_total;
struct net_device *dev;
int retval;
rx_total = tx_total = 0;
/* we are running as tasklet, so locking dev_base
* for reading should be OK */
read_lock(&dev_base_lock);
rcu_read_lock();
for (dev = dev_base; dev; dev = dev->next) {
struct net_device_stats *stats;
struct in_device *in_dev = __in_dev_get_rcu(dev);
if (!in_dev || !in_dev->ifa_list)
continue;
if (LOOPBACK(in_dev->ifa_list->ifa_local))
continue;
if (!dev->get_stats)
continue;
stats = dev->get_stats(dev);
rx_total += stats->rx_packets;
tx_total += stats->tx_packets;
}
rcu_read_unlock();
read_unlock(&dev_base_lock);
retval = 0;
if (rx_total != rx_total_last) {
rx_total_last = rx_total;
retval |= LED_LAN_RCV;
}
if (tx_total != tx_total_last) {
tx_total_last = tx_total;
retval |= LED_LAN_TX;
}
return retval;
#endif
}
/*
**
** led_get_diskio_activity()
**
** calculate if there was disk-io in the system
**
*/
static __inline__ int led_get_diskio_activity(void)
{
static unsigned long last_pgpgin, last_pgpgout;
struct page_state pgstat;
int changed;
get_full_page_state(&pgstat); /* get no of sectors in & out */
/* Just use a very simple calculation here. Do not care about overflow,
since we only want to know if there was activity or not. */
changed = (pgstat.pgpgin != last_pgpgin) || (pgstat.pgpgout != last_pgpgout);
last_pgpgin = pgstat.pgpgin;
last_pgpgout = pgstat.pgpgout;
return (changed ? LED_DISK_IO : 0);
}
/*
** led_tasklet_func()
**
** is scheduled at every timer interrupt from time.c and
** updates the chassis LCD/LED
TODO:
- display load average (older machines like 715/64 have 4 "free" LED's for that)
- optimizations
*/
#define HEARTBEAT_LEN (HZ*6/100)
#define HEARTBEAT_2ND_RANGE_START (HZ*22/100)
#define HEARTBEAT_2ND_RANGE_END (HEARTBEAT_2ND_RANGE_START + HEARTBEAT_LEN)
#define NORMALIZED_COUNT(count) (count/(HZ/100))
static void led_tasklet_func(unsigned long unused)
{
static unsigned char lastleds;
unsigned char currentleds; /* stores current value of the LEDs */
static unsigned long count; /* static incremented value, not wrapped */
static unsigned long count_HZ; /* counter in range 0..HZ */
/* exit if not initialized */
if (!led_func_ptr)
return;
/* increment the local counters */
++count;
if (++count_HZ == HZ)
count_HZ = 0;
currentleds = lastleds;
if (led_heartbeat)
{
/* flash heartbeat-LED like a real heart (2 x short then a long delay) */
if (count_HZ<HEARTBEAT_LEN ||
(count_HZ>=HEARTBEAT_2ND_RANGE_START && count_HZ<HEARTBEAT_2ND_RANGE_END))
currentleds |= LED_HEARTBEAT;
else
currentleds &= ~LED_HEARTBEAT;
}
/* look for network activity and flash LEDs respectively */
if (led_lanrxtx && ((NORMALIZED_COUNT(count)+(8/2)) & 7) == 0)
{
currentleds &= ~(LED_LAN_RCV | LED_LAN_TX);
currentleds |= led_get_net_activity();
}
/* avoid to calculate diskio-stats at same irq as netio-stats */
if (led_diskio && (NORMALIZED_COUNT(count) & 7) == 0)
{
currentleds &= ~LED_DISK_IO;
currentleds |= led_get_diskio_activity();
}
/* blink all LEDs twice a second if we got an Oops (HPMC) */
if (oops_in_progress) {
currentleds = (count_HZ<=(HZ/2)) ? 0 : 0xff;
}
/* update the LCD/LEDs */
if (currentleds != lastleds) {
led_func_ptr(currentleds);
lastleds = currentleds;
}
}
/* main led tasklet struct (scheduled from time.c) */
DECLARE_TASKLET_DISABLED(led_tasklet, led_tasklet_func, 0);
/*
** led_halt()
**
** called by the reboot notifier chain at shutdown and stops all
** LED/LCD activities.
**
*/
static int led_halt(struct notifier_block *, unsigned long, void *);
static struct notifier_block led_notifier = {
.notifier_call = led_halt,
};
static int led_halt(struct notifier_block *nb, unsigned long event, void *buf)
{
char *txt;
switch (event) {
case SYS_RESTART: txt = "SYSTEM RESTART";
break;
case SYS_HALT: txt = "SYSTEM HALT";
break;
case SYS_POWER_OFF: txt = "SYSTEM POWER OFF";
break;
default: return NOTIFY_DONE;
}
/* completely stop the LED/LCD tasklet */
tasklet_disable(&led_tasklet);
if (lcd_info.model == DISPLAY_MODEL_LCD)
lcd_print(txt);
else
if (led_func_ptr)
led_func_ptr(0xff); /* turn all LEDs ON */
unregister_reboot_notifier(&led_notifier);
return NOTIFY_OK;
}
/*
** register_led_driver()
**
** registers an external LED or LCD for usage by this driver.
** currently only LCD-, LASI- and ASP-style LCD/LED's are supported.
**
*/
int __init register_led_driver(int model, unsigned long cmd_reg, unsigned long data_reg)
{
static int initialized;
if (initialized || !data_reg)
return 1;
lcd_info.model = model; /* store the values */
LCD_CMD_REG = (cmd_reg == LED_CMD_REG_NONE) ? 0 : cmd_reg;
switch (lcd_info.model) {
case DISPLAY_MODEL_LCD:
LCD_DATA_REG = data_reg;
printk(KERN_INFO "LCD display at %lx,%lx registered\n",
LCD_CMD_REG , LCD_DATA_REG);
led_func_ptr = led_LCD_driver;
lcd_print( lcd_text_default );
led_type = LED_HASLCD;
break;
case DISPLAY_MODEL_LASI:
LED_DATA_REG = data_reg;
led_func_ptr = led_LASI_driver;
printk(KERN_INFO "LED display at %lx registered\n", LED_DATA_REG);
led_type = LED_NOLCD;
break;
case DISPLAY_MODEL_OLD_ASP:
LED_DATA_REG = data_reg;
led_func_ptr = led_ASP_driver;
printk(KERN_INFO "LED (ASP-style) display at %lx registered\n",
LED_DATA_REG);
led_type = LED_NOLCD;
break;
default:
printk(KERN_ERR "%s: Wrong LCD/LED model %d !\n",
__FUNCTION__, lcd_info.model);
return 1;
}
/* mark the LCD/LED driver now as initialized and
* register to the reboot notifier chain */
initialized++;
register_reboot_notifier(&led_notifier);
/* start the led tasklet for the first time */
tasklet_enable(&led_tasklet);
return 0;
}
/*
** register_led_regions()
**
** register_led_regions() registers the LCD/LED regions for /procfs.
** At bootup - where the initialisation of the LCD/LED normally happens -
** not all internal structures of request_region() are properly set up,
** so that we delay the led-registration until after busdevices_init()
** has been executed.
**
*/
void __init register_led_regions(void)
{
switch (lcd_info.model) {
case DISPLAY_MODEL_LCD:
request_mem_region((unsigned long)LCD_CMD_REG, 1, "lcd_cmd");
request_mem_region((unsigned long)LCD_DATA_REG, 1, "lcd_data");
break;
case DISPLAY_MODEL_LASI:
case DISPLAY_MODEL_OLD_ASP:
request_mem_region((unsigned long)LED_DATA_REG, 1, "led_data");
break;
}
}
/*
**
** lcd_print()
**
** Displays the given string on the LCD-Display of newer machines.
** lcd_print() disables the timer-based led tasklet during its
** execution and enables it afterwards again.
**
*/
int lcd_print( char *str )
{
int i;
if (!led_func_ptr || lcd_info.model != DISPLAY_MODEL_LCD)
return 0;
/* temporarily disable the led tasklet */
tasklet_disable(&led_tasklet);
/* copy display string to buffer for procfs */
strlcpy(lcd_text, str, sizeof(lcd_text));
/* Set LCD Cursor to 1st character */
gsc_writeb(lcd_info.reset_cmd1, LCD_CMD_REG);
udelay(lcd_info.min_cmd_delay);
/* Print the string */
for (i=0; i < lcd_info.lcd_width; i++) {
if (str && *str)
gsc_writeb(*str++, LCD_DATA_REG);
else
gsc_writeb(' ', LCD_DATA_REG);
udelay(lcd_info.min_cmd_delay);
}
/* re-enable the led tasklet */
tasklet_enable(&led_tasklet);
return lcd_info.lcd_width;
}
/*
** led_init()
**
** led_init() is called very early in the bootup-process from setup.c
** and asks the PDC for an usable chassis LCD or LED.
** If the PDC doesn't return any info, then the LED
** is detected by lasi.c or asp.c and registered with the
** above functions lasi_led_init() or asp_led_init().
** KittyHawk machines have often a buggy PDC, so that
** we explicitly check for those machines here.
*/
int __init led_init(void)
{
struct pdc_chassis_info chassis_info;
int ret;
snprintf(lcd_text_default, sizeof(lcd_text_default),
"Linux %s", system_utsname.release);
/* Work around the buggy PDC of KittyHawk-machines */
switch (CPU_HVERSION) {
case 0x580: /* KittyHawk DC2-100 (K100) */
case 0x581: /* KittyHawk DC3-120 (K210) */
case 0x582: /* KittyHawk DC3 100 (K400) */
case 0x583: /* KittyHawk DC3 120 (K410) */
case 0x58B: /* KittyHawk DC2 100 (K200) */
printk(KERN_INFO "%s: KittyHawk-Machine (hversion 0x%x) found, "
"LED detection skipped.\n", __FILE__, CPU_HVERSION);
goto found; /* use the preinitialized values of lcd_info */
}
/* initialize the struct, so that we can check for valid return values */
lcd_info.model = DISPLAY_MODEL_NONE;
chassis_info.actcnt = chassis_info.maxcnt = 0;
ret = pdc_chassis_info(&chassis_info, &lcd_info, sizeof(lcd_info));
if (ret == PDC_OK) {
DPRINTK((KERN_INFO "%s: chassis info: model=%d (%s), "
"lcd_width=%d, cmd_delay=%u,\n"
"%s: sizecnt=%d, actcnt=%ld, maxcnt=%ld\n",
__FILE__, lcd_info.model,
(lcd_info.model==DISPLAY_MODEL_LCD) ? "LCD" :
(lcd_info.model==DISPLAY_MODEL_LASI) ? "LED" : "unknown",
lcd_info.lcd_width, lcd_info.min_cmd_delay,
__FILE__, sizeof(lcd_info),
chassis_info.actcnt, chassis_info.maxcnt));
DPRINTK((KERN_INFO "%s: cmd=%p, data=%p, reset1=%x, reset2=%x, act_enable=%d\n",
__FILE__, lcd_info.lcd_cmd_reg_addr,
lcd_info.lcd_data_reg_addr, lcd_info.reset_cmd1,
lcd_info.reset_cmd2, lcd_info.act_enable ));
/* check the results. Some machines have a buggy PDC */
if (chassis_info.actcnt <= 0 || chassis_info.actcnt != chassis_info.maxcnt)
goto not_found;
switch (lcd_info.model) {
case DISPLAY_MODEL_LCD: /* LCD display */
if (chassis_info.actcnt <
offsetof(struct pdc_chassis_lcd_info_ret_block, _pad)-1)
goto not_found;
if (!lcd_info.act_enable) {
DPRINTK((KERN_INFO "PDC prohibited usage of the LCD.\n"));
goto not_found;
}
break;
case DISPLAY_MODEL_NONE: /* no LED or LCD available */
printk(KERN_INFO "PDC reported no LCD or LED.\n");
goto not_found;
case DISPLAY_MODEL_LASI: /* Lasi style 8 bit LED display */
if (chassis_info.actcnt != 8 && chassis_info.actcnt != 32)
goto not_found;
break;
default:
printk(KERN_WARNING "PDC reported unknown LCD/LED model %d\n",
lcd_info.model);
goto not_found;
} /* switch() */
found:
/* register the LCD/LED driver */
register_led_driver(lcd_info.model, LCD_CMD_REG, LCD_DATA_REG);
return 0;
} else { /* if() */
DPRINTK((KERN_INFO "pdc_chassis_info call failed with retval = %d\n", ret));
}
not_found:
lcd_info.model = DISPLAY_MODEL_NONE;
return 1;
}
#ifdef CONFIG_PROC_FS
module_init(led_create_procfs)
#endif