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| 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 | |
| parent | x86, msr: Create _on_cpu helpers for {rw,wr}msr_safe_regs() (diff) | |
| download | linux-dev-ff55df53dfdd338906c8ba9d1f4a759b86b869d5.tar.xz linux-dev-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.txt | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/msr.h | 10 | ||||
| -rw-r--r-- | arch/x86/kernel/msr.c | 51 |
3 files changed, 60 insertions, 2 deletions
diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index dbea4f95fc85..1c058b552e93 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 8e56712aa176..7e2b6ba962ff 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 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) |