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Diffstat (limited to 'arch/x86/kernel/cpuid.c')
-rw-r--r--arch/x86/kernel/cpuid.c60
1 files changed, 27 insertions, 33 deletions
diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index 05c9936a16c..288e7a6598a 100644
--- a/arch/x86/kernel/cpuid.c
+++ b/arch/x86/kernel/cpuid.c
@@ -1,6 +1,6 @@
/* ----------------------------------------------------------------------- *
- *
- * Copyright 2000 H. Peter Anvin - All Rights Reserved
+ *
+ * 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
@@ -17,6 +17,10 @@
* 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.
*/
@@ -43,35 +47,24 @@
static struct class *cpuid_class;
-struct cpuid_command {
- u32 reg;
- u32 *data;
+struct cpuid_regs {
+ u32 eax, ebx, ecx, edx;
};
static void cpuid_smp_cpuid(void *cmd_block)
{
- struct cpuid_command *cmd = (struct cpuid_command *)cmd_block;
-
- cpuid(cmd->reg, &cmd->data[0], &cmd->data[1], &cmd->data[2],
- &cmd->data[3]);
-}
-
-static inline void do_cpuid(int cpu, u32 reg, u32 * data)
-{
- struct cpuid_command cmd;
-
- cmd.reg = reg;
- cmd.data = data;
+ struct cpuid_regs *cmd = (struct cpuid_regs *)cmd_block;
- smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1, 1);
+ 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;
- lock_kernel();
-
+ mutex_lock(&inode->i_mutex);
switch (orig) {
case 0:
file->f_pos = offset;
@@ -84,8 +77,7 @@ static loff_t cpuid_seek(struct file *file, loff_t offset, int orig)
default:
ret = -EINVAL;
}
-
- unlock_kernel();
+ mutex_unlock(&inode->i_mutex);
return ret;
}
@@ -93,19 +85,21 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
size_t count, loff_t * ppos)
{
char __user *tmp = buf;
- u32 data[4];
- u32 reg = *ppos;
+ 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) {
- do_cpuid(cpu, reg, data);
- if (copy_to_user(tmp, &data, 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 = reg++;
+ *ppos = ++pos;
}
return tmp - buf;
@@ -157,20 +151,20 @@ static int __cpuinit cpuid_class_cpu_callback(struct notifier_block *nfb,
switch (action) {
case CPU_UP_PREPARE:
- case CPU_UP_PREPARE_FROZEN:
err = cpuid_device_create(cpu);
break;
case CPU_UP_CANCELED:
- case CPU_UP_CANCELED_FROZEN:
case CPU_DEAD:
- case CPU_DEAD_FROZEN:
cpuid_device_destroy(cpu);
break;
+ case CPU_UP_CANCELED_FROZEN:
+ destroy_suspended_device(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
+ break;
}
return err ? NOTIFY_BAD : NOTIFY_OK;
}
-static struct notifier_block __cpuinitdata cpuid_class_cpu_notifier =
+static struct notifier_block __refdata cpuid_class_cpu_notifier =
{
.notifier_call = cpuid_class_cpu_callback,
};
@@ -193,7 +187,7 @@ static int __init cpuid_init(void)
}
for_each_online_cpu(i) {
err = cpuid_device_create(i);
- if (err != 0)
+ if (err != 0)
goto out_class;
}
register_hotcpu_notifier(&cpuid_class_cpu_notifier);
@@ -208,7 +202,7 @@ out_class:
}
class_destroy(cpuid_class);
out_chrdev:
- unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");
+ unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");
out:
return err;
}