linux/arch/x86/kernel/cpuid.c
Rafael J. Wysocki b844eba292 PM: Remove destroy_suspended_device()
After 2.6.24 there was a plan to make the PM core acquire all device
semaphores during a suspend/hibernation to protect itself from
concurrent operations involving device objects.  That proved to be
too heavy-handed and we found a better way to achieve the goal, but
before it happened, we had introduced the functions
device_pm_schedule_removal() and destroy_suspended_device() to allow
drivers to "safely" destroy a suspended device and we had adapted some
drivers to use them.  Now that these functions are no longer necessary,
it seems reasonable to remove them and modify their users to use the
normal device unregistration instead.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-04-19 19:10:28 -07:00

224 lines
5.1 KiB
C

/* ----------------------------------------------------------------------- *
*
* Copyright 2000-2008 H. Peter Anvin - All Rights Reserved
*
* 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, Inc., 675 Mass Ave, Cambridge MA 02139,
* USA; either version 2 of the License, or (at your option) any later
* version; incorporated herein by reference.
*
* ----------------------------------------------------------------------- */
/*
* x86 CPUID access device
*
* This device is accessed by lseek() to the appropriate CPUID level
* and then read in chunks of 16 bytes. A larger size means multiple
* reads of consecutive levels.
*
* The lower 32 bits of the file position is used as the incoming %eax,
* and the upper 32 bits of the file position as the incoming %ecx,
* the latter intended for "counting" eax levels like eax=4.
*
* This driver uses /dev/cpu/%d/cpuid where %d is the minor number, and on
* an SMP box will direct the access to CPU %d.
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/fcntl.h>
#include <linux/init.h>
#include <linux/poll.h>
#include <linux/smp.h>
#include <linux/major.h>
#include <linux/fs.h>
#include <linux/smp_lock.h>
#include <linux/device.h>
#include <linux/cpu.h>
#include <linux/notifier.h>
#include <asm/processor.h>
#include <asm/msr.h>
#include <asm/uaccess.h>
#include <asm/system.h>
static struct class *cpuid_class;
struct cpuid_regs {
u32 eax, ebx, ecx, edx;
};
static void cpuid_smp_cpuid(void *cmd_block)
{
struct cpuid_regs *cmd = (struct cpuid_regs *)cmd_block;
cpuid_count(cmd->eax, cmd->ecx,
&cmd->eax, &cmd->ebx, &cmd->ecx, &cmd->edx);
}
static loff_t cpuid_seek(struct file *file, loff_t offset, int orig)
{
loff_t ret;
struct inode *inode = file->f_mapping->host;
mutex_lock(&inode->i_mutex);
switch (orig) {
case 0:
file->f_pos = offset;
ret = file->f_pos;
break;
case 1:
file->f_pos += offset;
ret = file->f_pos;
break;
default:
ret = -EINVAL;
}
mutex_unlock(&inode->i_mutex);
return ret;
}
static ssize_t cpuid_read(struct file *file, char __user *buf,
size_t count, loff_t * ppos)
{
char __user *tmp = buf;
struct cpuid_regs cmd;
int cpu = iminor(file->f_path.dentry->d_inode);
u64 pos = *ppos;
if (count % 16)
return -EINVAL; /* Invalid chunk size */
for (; count; count -= 16) {
cmd.eax = pos;
cmd.ecx = pos >> 32;
smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1, 1);
if (copy_to_user(tmp, &cmd, 16))
return -EFAULT;
tmp += 16;
*ppos = ++pos;
}
return tmp - buf;
}
static int cpuid_open(struct inode *inode, struct file *file)
{
unsigned int cpu = iminor(file->f_path.dentry->d_inode);
struct cpuinfo_x86 *c = &cpu_data(cpu);
if (cpu >= NR_CPUS || !cpu_online(cpu))
return -ENXIO; /* No such CPU */
if (c->cpuid_level < 0)
return -EIO; /* CPUID not supported */
return 0;
}
/*
* File operations we support
*/
static const struct file_operations cpuid_fops = {
.owner = THIS_MODULE,
.llseek = cpuid_seek,
.read = cpuid_read,
.open = cpuid_open,
};
static __cpuinit int cpuid_device_create(int cpu)
{
struct device *dev;
dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu),
"cpu%d", cpu);
return IS_ERR(dev) ? PTR_ERR(dev) : 0;
}
static void cpuid_device_destroy(int cpu)
{
device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
}
static int __cpuinit cpuid_class_cpu_callback(struct notifier_block *nfb,
unsigned long action,
void *hcpu)
{
unsigned int cpu = (unsigned long)hcpu;
int err = 0;
switch (action) {
case CPU_UP_PREPARE:
err = cpuid_device_create(cpu);
break;
case CPU_UP_CANCELED:
case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
cpuid_device_destroy(cpu);
break;
}
return err ? NOTIFY_BAD : NOTIFY_OK;
}
static struct notifier_block __refdata cpuid_class_cpu_notifier =
{
.notifier_call = cpuid_class_cpu_callback,
};
static int __init cpuid_init(void)
{
int i, err = 0;
i = 0;
if (register_chrdev(CPUID_MAJOR, "cpu/cpuid", &cpuid_fops)) {
printk(KERN_ERR "cpuid: unable to get major %d for cpuid\n",
CPUID_MAJOR);
err = -EBUSY;
goto out;
}
cpuid_class = class_create(THIS_MODULE, "cpuid");
if (IS_ERR(cpuid_class)) {
err = PTR_ERR(cpuid_class);
goto out_chrdev;
}
for_each_online_cpu(i) {
err = cpuid_device_create(i);
if (err != 0)
goto out_class;
}
register_hotcpu_notifier(&cpuid_class_cpu_notifier);
err = 0;
goto out;
out_class:
i = 0;
for_each_online_cpu(i) {
cpuid_device_destroy(i);
}
class_destroy(cpuid_class);
out_chrdev:
unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");
out:
return err;
}
static void __exit cpuid_exit(void)
{
int cpu = 0;
for_each_online_cpu(cpu)
cpuid_device_destroy(cpu);
class_destroy(cpuid_class);
unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");
unregister_hotcpu_notifier(&cpuid_class_cpu_notifier);
}
module_init(cpuid_init);
module_exit(cpuid_exit);
MODULE_AUTHOR("H. Peter Anvin <hpa@zytor.com>");
MODULE_DESCRIPTION("x86 generic CPUID driver");
MODULE_LICENSE("GPL");