summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorH. Peter Anvin <hpa@zytor.com>2009-08-31 14:16:57 -0700
committerH. Peter Anvin <hpa@zytor.com>2009-08-31 16:16:04 -0700
commitff55df53dfdd338906c8ba9d1f4a759b86b869d5 (patch)
tree80ccb646dfd40beeb839d4c70624ba34dbcd5795
parent8b956bf1f0f2b552ed93cf6cafe823edff298b3b (diff)
downloadlinux-3.10-ff55df53dfdd338906c8ba9d1f4a759b86b869d5.tar.gz
linux-3.10-ff55df53dfdd338906c8ba9d1f4a759b86b869d5.tar.bz2
linux-3.10-ff55df53dfdd338906c8ba9d1f4a759b86b869d5.zip
x86, msr: Export the register-setting MSR functions via /dev/*/msr
Make it possible to access the all-register-setting/getting MSR functions via the MSR driver. This is implemented as an ioctl() on the standard MSR device node. Signed-off-by: H. Peter Anvin <hpa@zytor.com> Cc: Borislav Petkov <petkovbb@gmail.com>
-rw-r--r--Documentation/ioctl/ioctl-number.txt1
-rw-r--r--arch/x86/include/asm/msr.h10
-rw-r--r--arch/x86/kernel/msr.c51
3 files changed, 60 insertions, 2 deletions
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt
index dbea4f95fc8..1c058b552e9 100644
--- a/Documentation/ioctl/ioctl-number.txt
+++ b/Documentation/ioctl/ioctl-number.txt
@@ -121,6 +121,7 @@ Code Seq# Include File Comments
'c' 00-7F linux/comstats.h conflict!
'c' 00-7F linux/coda.h conflict!
'c' 80-9F arch/s390/include/asm/chsc.h
+'c' A0-AF arch/x86/include/asm/msr.h
'd' 00-FF linux/char/drm/drm/h conflict!
'd' F0-FF linux/digi1.h
'e' all linux/digi1.h conflict!
diff --git a/arch/x86/include/asm/msr.h b/arch/x86/include/asm/msr.h
index 8e56712aa17..7e2b6ba962f 100644
--- a/arch/x86/include/asm/msr.h
+++ b/arch/x86/include/asm/msr.h
@@ -3,10 +3,16 @@
#include <asm/msr-index.h>
-#ifdef __KERNEL__
#ifndef __ASSEMBLY__
#include <linux/types.h>
+#include <linux/ioctl.h>
+
+#define X86_IOC_RDMSR_REGS _IOWR('c', 0xA0, __u32[8])
+#define X86_IOC_WRMSR_REGS _IOWR('c', 0xA1, __u32[8])
+
+#ifdef __KERNEL__
+
#include <asm/asm.h>
#include <asm/errno.h>
#include <asm/cpumask.h>
@@ -286,6 +292,6 @@ static inline int wrmsr_safe_regs_on_cpu(unsigned int cpu, u32 regs[8])
return wrmsr_safe_regs(regs);
}
#endif /* CONFIG_SMP */
-#endif /* __ASSEMBLY__ */
#endif /* __KERNEL__ */
+#endif /* __ASSEMBLY__ */
#endif /* _ASM_X86_MSR_H */
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index 2cfbb4b2c42..7dd95009417 100644
--- a/arch/x86/kernel/msr.c
+++ b/arch/x86/kernel/msr.c
@@ -1,6 +1,7 @@
/* ----------------------------------------------------------------------- *
*
* Copyright 2000-2008 H. Peter Anvin - All Rights Reserved
+ * Copyright 2009 Intel Corporation; author: H. Peter Anvin
*
* 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
@@ -121,6 +122,54 @@ static ssize_t msr_write(struct file *file, const char __user *buf,
return bytes ? bytes : err;
}
+static long msr_ioctl(struct file *file, unsigned int ioc, unsigned long arg)
+{
+ u32 __user *uregs = (u32 __user *)arg;
+ u32 regs[8];
+ int cpu = iminor(file->f_path.dentry->d_inode);
+ int err;
+
+ switch (ioc) {
+ case X86_IOC_RDMSR_REGS:
+ if (!(file->f_mode & FMODE_READ)) {
+ err = -EBADF;
+ break;
+ }
+ if (copy_from_user(&regs, uregs, sizeof regs)) {
+ err = -EFAULT;
+ break;
+ }
+ err = rdmsr_safe_regs_on_cpu(cpu, regs);
+ if (err)
+ break;
+ if (copy_to_user(uregs, &regs, sizeof regs))
+ err = -EFAULT;
+ break;
+
+ case X86_IOC_WRMSR_REGS:
+ if (!(file->f_mode & FMODE_WRITE)) {
+ err = -EBADF;
+ break;
+ }
+ if (copy_from_user(&regs, uregs, sizeof regs)) {
+ err = -EFAULT;
+ break;
+ }
+ err = wrmsr_safe_regs_on_cpu(cpu, regs);
+ if (err)
+ break;
+ if (copy_to_user(uregs, &regs, sizeof regs))
+ err = -EFAULT;
+ break;
+
+ default:
+ err = -ENOTTY;
+ break;
+ }
+
+ return err;
+}
+
static int msr_open(struct inode *inode, struct file *file)
{
unsigned int cpu = iminor(file->f_path.dentry->d_inode);
@@ -151,6 +200,8 @@ static const struct file_operations msr_fops = {
.read = msr_read,
.write = msr_write,
.open = msr_open,
+ .unlocked_ioctl = msr_ioctl,
+ .compat_ioctl = msr_ioctl,
};
static int __cpuinit msr_device_create(int cpu)