diff options
| author | H. Peter Anvin <hpa@zytor.com> | 2009-08-31 14:16:57 -0700 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2009-08-31 16:16:04 -0700 |
| commit | ff55df53dfdd338906c8ba9d1f4a759b86b869d5 (patch) | |
| tree | 80ccb646dfd40beeb839d4c70624ba34dbcd5795 /arch/x86/kernel/msr.c | |
| parent | 8b956bf1f0f2b552ed93cf6cafe823edff298b3b (diff) | |
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>
Diffstat (limited to 'arch/x86/kernel/msr.c')
| -rw-r--r-- | arch/x86/kernel/msr.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c index 2cfbb4b2c422..7dd950094178 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(®s, uregs, sizeof regs)) { + err = -EFAULT; + break; + } + err = rdmsr_safe_regs_on_cpu(cpu, regs); + if (err) + break; + if (copy_to_user(uregs, ®s, sizeof regs)) + err = -EFAULT; + break; + + case X86_IOC_WRMSR_REGS: + if (!(file->f_mode & FMODE_WRITE)) { + err = -EBADF; + break; + } + if (copy_from_user(®s, uregs, sizeof regs)) { + err = -EFAULT; + break; + } + err = wrmsr_safe_regs_on_cpu(cpu, regs); + if (err) + break; + if (copy_to_user(uregs, ®s, 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) |