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linux/drivers/char/i8k.c
Frederic Weisbecker d79b6f4de5 procfs: Push down the bkl from ioctl 
Push down the bkl from procfs's ioctl main handler to its users.
Only three procfs users implement an ioctl (non unlocked) handler.
Turn them into unlocked_ioctl and push down the Devil inside.

v2: PDE(inode)->data doesn't need to be under bkl
v3: And don't forget to git-add the result
v4: Use wrappers to pushdown instead of an invasive and error prone
    handlers surgery.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: John Kacur <jkacur@redhat.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
2010-05-17 03:06:12 +02:00

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/*
* i8k.c -- Linux driver for accessing the SMM BIOS on Dell laptops.
* See http://www.debian.org/~dz/i8k/ for more information
* and for latest version of this driver.
*
* Copyright (C) 2001 Massimo Dal Zotto <dz@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, 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.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/dmi.h>
#include <linux/capability.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
#include <asm/io.h>
#include <linux/i8k.h>
#define I8K_VERSION "1.14 21/02/2005"
#define I8K_SMM_FN_STATUS 0x0025
#define I8K_SMM_POWER_STATUS 0x0069
#define I8K_SMM_SET_FAN 0x01a3
#define I8K_SMM_GET_FAN 0x00a3
#define I8K_SMM_GET_SPEED 0x02a3
#define I8K_SMM_GET_TEMP 0x10a3
#define I8K_SMM_GET_DELL_SIG1 0xfea3
#define I8K_SMM_GET_DELL_SIG2 0xffa3
#define I8K_SMM_BIOS_VERSION 0x00a6
#define I8K_FAN_MULT 30
#define I8K_MAX_TEMP 127
#define I8K_FN_NONE 0x00
#define I8K_FN_UP 0x01
#define I8K_FN_DOWN 0x02
#define I8K_FN_MUTE 0x04
#define I8K_FN_MASK 0x07
#define I8K_FN_SHIFT 8
#define I8K_POWER_AC 0x05
#define I8K_POWER_BATTERY 0x01
#define I8K_TEMPERATURE_BUG 1
static char bios_version[4];
MODULE_AUTHOR("Massimo Dal Zotto (dz@debian.org)");
MODULE_DESCRIPTION("Driver for accessing SMM BIOS on Dell laptops");
MODULE_LICENSE("GPL");
static int force;
module_param(force, bool, 0);
MODULE_PARM_DESC(force, "Force loading without checking for supported models");
static int ignore_dmi;
module_param(ignore_dmi, bool, 0);
MODULE_PARM_DESC(ignore_dmi, "Continue probing hardware even if DMI data does not match");
static int restricted;
module_param(restricted, bool, 0);
MODULE_PARM_DESC(restricted, "Allow fan control if SYS_ADMIN capability set");
static int power_status;
module_param(power_status, bool, 0600);
MODULE_PARM_DESC(power_status, "Report power status in /proc/i8k");
static int fan_mult = I8K_FAN_MULT;
module_param(fan_mult, int, 0);
MODULE_PARM_DESC(fan_mult, "Factor to multiply fan speed with");
static int i8k_open_fs(struct inode *inode, struct file *file);
static long i8k_ioctl(struct file *, unsigned int, unsigned long);
static const struct file_operations i8k_fops = {
.owner = THIS_MODULE,
.open = i8k_open_fs,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
.unlocked_ioctl = i8k_ioctl,
};
struct smm_regs {
unsigned int eax;
unsigned int ebx __attribute__ ((packed));
unsigned int ecx __attribute__ ((packed));
unsigned int edx __attribute__ ((packed));
unsigned int esi __attribute__ ((packed));
unsigned int edi __attribute__ ((packed));
};
static inline const char *i8k_get_dmi_data(int field)
{
const char *dmi_data = dmi_get_system_info(field);
return dmi_data && *dmi_data ? dmi_data : "?";
}
/*
* Call the System Management Mode BIOS. Code provided by Jonathan Buzzard.
*/
static int i8k_smm(struct smm_regs *regs)
{
int rc;
int eax = regs->eax;
#if defined(CONFIG_X86_64)
asm("pushq %%rax\n\t"
"movl 0(%%rax),%%edx\n\t"
"pushq %%rdx\n\t"
"movl 4(%%rax),%%ebx\n\t"
"movl 8(%%rax),%%ecx\n\t"
"movl 12(%%rax),%%edx\n\t"
"movl 16(%%rax),%%esi\n\t"
"movl 20(%%rax),%%edi\n\t"
"popq %%rax\n\t"
"out %%al,$0xb2\n\t"
"out %%al,$0x84\n\t"
"xchgq %%rax,(%%rsp)\n\t"
"movl %%ebx,4(%%rax)\n\t"
"movl %%ecx,8(%%rax)\n\t"
"movl %%edx,12(%%rax)\n\t"
"movl %%esi,16(%%rax)\n\t"
"movl %%edi,20(%%rax)\n\t"
"popq %%rdx\n\t"
"movl %%edx,0(%%rax)\n\t"
"lahf\n\t"
"shrl $8,%%eax\n\t"
"andl $1,%%eax\n"
:"=a"(rc)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#else
asm("pushl %%eax\n\t"
"movl 0(%%eax),%%edx\n\t"
"push %%edx\n\t"
"movl 4(%%eax),%%ebx\n\t"
"movl 8(%%eax),%%ecx\n\t"
"movl 12(%%eax),%%edx\n\t"
"movl 16(%%eax),%%esi\n\t"
"movl 20(%%eax),%%edi\n\t"
"popl %%eax\n\t"
"out %%al,$0xb2\n\t"
"out %%al,$0x84\n\t"
"xchgl %%eax,(%%esp)\n\t"
"movl %%ebx,4(%%eax)\n\t"
"movl %%ecx,8(%%eax)\n\t"
"movl %%edx,12(%%eax)\n\t"
"movl %%esi,16(%%eax)\n\t"
"movl %%edi,20(%%eax)\n\t"
"popl %%edx\n\t"
"movl %%edx,0(%%eax)\n\t"
"lahf\n\t"
"shrl $8,%%eax\n\t"
"andl $1,%%eax\n":"=a"(rc)
: "a"(regs)
: "%ebx", "%ecx", "%edx", "%esi", "%edi", "memory");
#endif
if (rc != 0 || (regs->eax & 0xffff) == 0xffff || regs->eax == eax)
return -EINVAL;
return 0;
}
/*
* Read the bios version. Return the version as an integer corresponding
* to the ascii value, for example "A17" is returned as 0x00413137.
*/
static int i8k_get_bios_version(void)
{
struct smm_regs regs = { .eax = I8K_SMM_BIOS_VERSION, };
return i8k_smm(&regs) ? : regs.eax;
}
/*
* Read the Fn key status.
*/
static int i8k_get_fn_status(void)
{
struct smm_regs regs = { .eax = I8K_SMM_FN_STATUS, };
int rc;
if ((rc = i8k_smm(&regs)) < 0)
return rc;
switch ((regs.eax >> I8K_FN_SHIFT) & I8K_FN_MASK) {
case I8K_FN_UP:
return I8K_VOL_UP;
case I8K_FN_DOWN:
return I8K_VOL_DOWN;
case I8K_FN_MUTE:
return I8K_VOL_MUTE;
default:
return 0;
}
}
/*
* Read the power status.
*/
static int i8k_get_power_status(void)
{
struct smm_regs regs = { .eax = I8K_SMM_POWER_STATUS, };
int rc;
if ((rc = i8k_smm(&regs)) < 0)
return rc;
return (regs.eax & 0xff) == I8K_POWER_AC ? I8K_AC : I8K_BATTERY;
}
/*
* Read the fan status.
*/
static int i8k_get_fan_status(int fan)
{
struct smm_regs regs = { .eax = I8K_SMM_GET_FAN, };
regs.ebx = fan & 0xff;
return i8k_smm(&regs) ? : regs.eax & 0xff;
}
/*
* Read the fan speed in RPM.
*/
static int i8k_get_fan_speed(int fan)
{
struct smm_regs regs = { .eax = I8K_SMM_GET_SPEED, };
regs.ebx = fan & 0xff;
return i8k_smm(&regs) ? : (regs.eax & 0xffff) * fan_mult;
}
/*
* Set the fan speed (off, low, high). Returns the new fan status.
*/
static int i8k_set_fan(int fan, int speed)
{
struct smm_regs regs = { .eax = I8K_SMM_SET_FAN, };
speed = (speed < 0) ? 0 : ((speed > I8K_FAN_MAX) ? I8K_FAN_MAX : speed);
regs.ebx = (fan & 0xff) | (speed << 8);
return i8k_smm(&regs) ? : i8k_get_fan_status(fan);
}
/*
* Read the cpu temperature.
*/
static int i8k_get_temp(int sensor)
{
struct smm_regs regs = { .eax = I8K_SMM_GET_TEMP, };
int rc;
int temp;
#ifdef I8K_TEMPERATURE_BUG
static int prev;
#endif
regs.ebx = sensor & 0xff;
if ((rc = i8k_smm(&regs)) < 0)
return rc;
temp = regs.eax & 0xff;
#ifdef I8K_TEMPERATURE_BUG
/*
* Sometimes the temperature sensor returns 0x99, which is out of range.
* In this case we return (once) the previous cached value. For example:
# 1003655137 00000058 00005a4b
# 1003655138 00000099 00003a80 <--- 0x99 = 153 degrees
# 1003655139 00000054 00005c52
*/
if (temp > I8K_MAX_TEMP) {
temp = prev;
prev = I8K_MAX_TEMP;
} else {
prev = temp;
}
#endif
return temp;
}
static int i8k_get_dell_signature(int req_fn)
{
struct smm_regs regs = { .eax = req_fn, };
int rc;
if ((rc = i8k_smm(&regs)) < 0)
return rc;
return regs.eax == 1145651527 && regs.edx == 1145392204 ? 0 : -1;
}
static int
i8k_ioctl_unlocked(struct file *fp, unsigned int cmd, unsigned long arg)
{
int val = 0;
int speed;
unsigned char buff[16];
int __user *argp = (int __user *)arg;
if (!argp)
return -EINVAL;
switch (cmd) {
case I8K_BIOS_VERSION:
val = i8k_get_bios_version();
break;
case I8K_MACHINE_ID:
memset(buff, 0, 16);
strlcpy(buff, i8k_get_dmi_data(DMI_PRODUCT_SERIAL), sizeof(buff));
break;
case I8K_FN_STATUS:
val = i8k_get_fn_status();
break;
case I8K_POWER_STATUS:
val = i8k_get_power_status();
break;
case I8K_GET_TEMP:
val = i8k_get_temp(0);
break;
case I8K_GET_SPEED:
if (copy_from_user(&val, argp, sizeof(int)))
return -EFAULT;
val = i8k_get_fan_speed(val);
break;
case I8K_GET_FAN:
if (copy_from_user(&val, argp, sizeof(int)))
return -EFAULT;
val = i8k_get_fan_status(val);
break;
case I8K_SET_FAN:
if (restricted && !capable(CAP_SYS_ADMIN))
return -EPERM;
if (copy_from_user(&val, argp, sizeof(int)))
return -EFAULT;
if (copy_from_user(&speed, argp + 1, sizeof(int)))
return -EFAULT;
val = i8k_set_fan(val, speed);
break;
default:
return -EINVAL;
}
if (val < 0)
return val;
switch (cmd) {
case I8K_BIOS_VERSION:
if (copy_to_user(argp, &val, 4))
return -EFAULT;
break;
case I8K_MACHINE_ID:
if (copy_to_user(argp, buff, 16))
return -EFAULT;
break;
default:
if (copy_to_user(argp, &val, sizeof(int)))
return -EFAULT;
break;
}
return 0;
}
static long i8k_ioctl(struct file *fp, unsigned int cmd, unsigned long arg)
{
long ret;
lock_kernel();
ret = i8k_ioctl_unlocked(fp, cmd, arg);
unlock_kernel();
return ret;
}
/*
* Print the information for /proc/i8k.
*/
static int i8k_proc_show(struct seq_file *seq, void *offset)
{
int fn_key, cpu_temp, ac_power;
int left_fan, right_fan, left_speed, right_speed;
cpu_temp = i8k_get_temp(0); /* 11100 µs */
left_fan = i8k_get_fan_status(I8K_FAN_LEFT); /* 580 µs */
right_fan = i8k_get_fan_status(I8K_FAN_RIGHT); /* 580 µs */
left_speed = i8k_get_fan_speed(I8K_FAN_LEFT); /* 580 µs */
right_speed = i8k_get_fan_speed(I8K_FAN_RIGHT); /* 580 µs */
fn_key = i8k_get_fn_status(); /* 750 µs */
if (power_status)
ac_power = i8k_get_power_status(); /* 14700 µs */
else
ac_power = -1;
/*
* Info:
*
* 1) Format version (this will change if format changes)
* 2) BIOS version
* 3) BIOS machine ID
* 4) Cpu temperature
* 5) Left fan status
* 6) Right fan status
* 7) Left fan speed
* 8) Right fan speed
* 9) AC power
* 10) Fn Key status
*/
return seq_printf(seq, "%s %s %s %d %d %d %d %d %d %d\n",
I8K_PROC_FMT,
bios_version,
i8k_get_dmi_data(DMI_PRODUCT_SERIAL),
cpu_temp,
left_fan, right_fan, left_speed, right_speed,
ac_power, fn_key);
}
static int i8k_open_fs(struct inode *inode, struct file *file)
{
return single_open(file, i8k_proc_show, NULL);
}
static struct dmi_system_id __initdata i8k_dmi_table[] = {
{
.ident = "Dell Inspiron",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
},
},
{
.ident = "Dell Latitude",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer"),
DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
},
},
{
.ident = "Dell Inspiron 2",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron"),
},
},
{
.ident = "Dell Latitude 2",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Latitude"),
},
},
{ /* UK Inspiron 6400 */
.ident = "Dell Inspiron 3",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "MM061"),
},
},
{
.ident = "Dell Inspiron 3",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "MP061"),
},
},
{
.ident = "Dell Precision",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Precision"),
},
},
{
.ident = "Dell Vostro",
.matches = {
DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
DMI_MATCH(DMI_PRODUCT_NAME, "Vostro"),
},
},
{ }
};
/*
* Probe for the presence of a supported laptop.
*/
static int __init i8k_probe(void)
{
char buff[4];
int version;
/*
* Get DMI information
*/
if (!dmi_check_system(i8k_dmi_table)) {
if (!ignore_dmi && !force)
return -ENODEV;
printk(KERN_INFO "i8k: not running on a supported Dell system.\n");
printk(KERN_INFO "i8k: vendor=%s, model=%s, version=%s\n",
i8k_get_dmi_data(DMI_SYS_VENDOR),
i8k_get_dmi_data(DMI_PRODUCT_NAME),
i8k_get_dmi_data(DMI_BIOS_VERSION));
}
strlcpy(bios_version, i8k_get_dmi_data(DMI_BIOS_VERSION), sizeof(bios_version));
/*
* Get SMM Dell signature
*/
if (i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG1) &&
i8k_get_dell_signature(I8K_SMM_GET_DELL_SIG2)) {
printk(KERN_ERR "i8k: unable to get SMM Dell signature\n");
if (!force)
return -ENODEV;
}
/*
* Get SMM BIOS version.
*/
version = i8k_get_bios_version();
if (version <= 0) {
printk(KERN_WARNING "i8k: unable to get SMM BIOS version\n");
} else {
buff[0] = (version >> 16) & 0xff;
buff[1] = (version >> 8) & 0xff;
buff[2] = (version) & 0xff;
buff[3] = '\0';
/*
* If DMI BIOS version is unknown use SMM BIOS version.
*/
if (!dmi_get_system_info(DMI_BIOS_VERSION))
strlcpy(bios_version, buff, sizeof(bios_version));
/*
* Check if the two versions match.
*/
if (strncmp(buff, bios_version, sizeof(bios_version)) != 0)
printk(KERN_WARNING "i8k: BIOS version mismatch: %s != %s\n",
buff, bios_version);
}
return 0;
}
static int __init i8k_init(void)
{
struct proc_dir_entry *proc_i8k;
/* Are we running on an supported laptop? */
if (i8k_probe())
return -ENODEV;
/* Register the proc entry */
proc_i8k = proc_create("i8k", 0, NULL, &i8k_fops);
if (!proc_i8k)
return -ENOENT;
printk(KERN_INFO
"Dell laptop SMM driver v%s Massimo Dal Zotto (dz@debian.org)\n",
I8K_VERSION);
return 0;
}
static void __exit i8k_exit(void)
{
remove_proc_entry("i8k", NULL);
}
module_init(i8k_init);
module_exit(i8k_exit);
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