diff options
Diffstat (limited to 'arch/x86_64/kernel/msr.c')
| -rw-r--r-- | arch/x86_64/kernel/msr.c | 279 |
1 files changed, 0 insertions, 279 deletions
diff --git a/arch/x86_64/kernel/msr.c b/arch/x86_64/kernel/msr.c deleted file mode 100644 index 598953ab0154..000000000000 --- a/arch/x86_64/kernel/msr.c +++ /dev/null @@ -1,279 +0,0 @@ -/* ----------------------------------------------------------------------- * - * - * Copyright 2000 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. - * - * ----------------------------------------------------------------------- */ - -/* - * msr.c - * - * x86 MSR access device - * - * This device is accessed by lseek() to the appropriate register number - * and then read/write in chunks of 8 bytes. A larger size means multiple - * reads or writes of the same register. - * - * This driver uses /dev/cpu/%d/msr where %d is the minor number, and on - * an SMP box will direct the access to CPU %d. - */ - -#include <linux/module.h> -#include <linux/config.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/smp_lock.h> -#include <linux/major.h> -#include <linux/fs.h> - -#include <asm/processor.h> -#include <asm/msr.h> -#include <asm/uaccess.h> -#include <asm/system.h> - -/* Note: "err" is handled in a funny way below. Otherwise one version - of gcc or another breaks. */ - -static inline int wrmsr_eio(u32 reg, u32 eax, u32 edx) -{ - int err; - - asm volatile ("1: wrmsr\n" - "2:\n" - ".section .fixup,\"ax\"\n" - "3: movl %4,%0\n" - " jmp 2b\n" - ".previous\n" - ".section __ex_table,\"a\"\n" - " .align 8\n" " .quad 1b,3b\n" ".previous":"=&bDS" (err) - :"a"(eax), "d"(edx), "c"(reg), "i"(-EIO), "0"(0)); - - return err; -} - -static inline int rdmsr_eio(u32 reg, u32 *eax, u32 *edx) -{ - int err; - - asm volatile ("1: rdmsr\n" - "2:\n" - ".section .fixup,\"ax\"\n" - "3: movl %4,%0\n" - " jmp 2b\n" - ".previous\n" - ".section __ex_table,\"a\"\n" - " .align 8\n" - " .quad 1b,3b\n" - ".previous":"=&bDS" (err), "=a"(*eax), "=d"(*edx) - :"c"(reg), "i"(-EIO), "0"(0)); - - return err; -} - -#ifdef CONFIG_SMP - -struct msr_command { - int cpu; - int err; - u32 reg; - u32 data[2]; -}; - -static void msr_smp_wrmsr(void *cmd_block) -{ - struct msr_command *cmd = (struct msr_command *)cmd_block; - - if (cmd->cpu == smp_processor_id()) - cmd->err = wrmsr_eio(cmd->reg, cmd->data[0], cmd->data[1]); -} - -static void msr_smp_rdmsr(void *cmd_block) -{ - struct msr_command *cmd = (struct msr_command *)cmd_block; - - if (cmd->cpu == smp_processor_id()) - cmd->err = rdmsr_eio(cmd->reg, &cmd->data[0], &cmd->data[1]); -} - -static inline int do_wrmsr(int cpu, u32 reg, u32 eax, u32 edx) -{ - struct msr_command cmd; - int ret; - - preempt_disable(); - if (cpu == smp_processor_id()) { - ret = wrmsr_eio(reg, eax, edx); - } else { - cmd.cpu = cpu; - cmd.reg = reg; - cmd.data[0] = eax; - cmd.data[1] = edx; - - smp_call_function(msr_smp_wrmsr, &cmd, 1, 1); - ret = cmd.err; - } - preempt_enable(); - return ret; -} - -static inline int do_rdmsr(int cpu, u32 reg, u32 * eax, u32 * edx) -{ - struct msr_command cmd; - int ret; - - preempt_disable(); - if (cpu == smp_processor_id()) { - ret = rdmsr_eio(reg, eax, edx); - } else { - cmd.cpu = cpu; - cmd.reg = reg; - - smp_call_function(msr_smp_rdmsr, &cmd, 1, 1); - - *eax = cmd.data[0]; - *edx = cmd.data[1]; - - ret = cmd.err; - } - preempt_enable(); - return ret; -} - -#else /* ! CONFIG_SMP */ - -static inline int do_wrmsr(int cpu, u32 reg, u32 eax, u32 edx) -{ - return wrmsr_eio(reg, eax, edx); -} - -static inline int do_rdmsr(int cpu, u32 reg, u32 *eax, u32 *edx) -{ - return rdmsr_eio(reg, eax, edx); -} - -#endif /* ! CONFIG_SMP */ - -static loff_t msr_seek(struct file *file, loff_t offset, int orig) -{ - loff_t ret = -EINVAL; - - lock_kernel(); - switch (orig) { - case 0: - file->f_pos = offset; - ret = file->f_pos; - break; - case 1: - file->f_pos += offset; - ret = file->f_pos; - } - unlock_kernel(); - return ret; -} - -static ssize_t msr_read(struct file *file, char __user * buf, - size_t count, loff_t * ppos) -{ - u32 __user *tmp = (u32 __user *) buf; - u32 data[2]; - size_t rv; - u32 reg = *ppos; - int cpu = iminor(file->f_dentry->d_inode); - int err; - - if (count % 8) - return -EINVAL; /* Invalid chunk size */ - - for (rv = 0; count; count -= 8) { - err = do_rdmsr(cpu, reg, &data[0], &data[1]); - if (err) - return err; - if (copy_to_user(tmp, &data, 8)) - return -EFAULT; - tmp += 2; - } - - return ((char __user *)tmp) - buf; -} - -static ssize_t msr_write(struct file *file, const char __user *buf, - size_t count, loff_t *ppos) -{ - const u32 __user *tmp = (const u32 __user *)buf; - u32 data[2]; - size_t rv; - u32 reg = *ppos; - int cpu = iminor(file->f_dentry->d_inode); - int err; - - if (count % 8) - return -EINVAL; /* Invalid chunk size */ - - for (rv = 0; count; count -= 8) { - if (copy_from_user(&data, tmp, 8)) - return -EFAULT; - err = do_wrmsr(cpu, reg, data[0], data[1]); - if (err) - return err; - tmp += 2; - } - - return ((char __user *)tmp) - buf; -} - -static int msr_open(struct inode *inode, struct file *file) -{ - unsigned int cpu = iminor(file->f_dentry->d_inode); - struct cpuinfo_x86 *c = &(cpu_data)[cpu]; - - if (cpu >= NR_CPUS || !cpu_online(cpu)) - return -ENXIO; /* No such CPU */ - if (!cpu_has(c, X86_FEATURE_MSR)) - return -EIO; /* MSR not supported */ - - return 0; -} - -/* - * File operations we support - */ -static struct file_operations msr_fops = { - .owner = THIS_MODULE, - .llseek = msr_seek, - .read = msr_read, - .write = msr_write, - .open = msr_open, -}; - -static int __init msr_init(void) -{ - if (register_chrdev(MSR_MAJOR, "cpu/msr", &msr_fops)) { - printk(KERN_ERR "msr: unable to get major %d for msr\n", - MSR_MAJOR); - return -EBUSY; - } - - return 0; -} - -static void __exit msr_exit(void) -{ - unregister_chrdev(MSR_MAJOR, "cpu/msr"); -} - -module_init(msr_init); -module_exit(msr_exit) - -MODULE_AUTHOR("H. Peter Anvin <hpa@zytor.com>"); -MODULE_DESCRIPTION("x86 generic MSR driver"); -MODULE_LICENSE("GPL"); |