+++ /dev/null
-/* ----------------------------------------------------------------------- *
- *
- * 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");
#define wrmsrl(msr,val) wrmsr(msr,(__u32)((__u64)(val)),((__u64)(val))>>32)
/* wrmsr with exception handling */
-#define wrmsr_safe(msr,a,b) ({ int ret__; \
- asm volatile("2: wrmsr ; xorl %0,%0\n" \
- "1:\n\t" \
- ".section .fixup,\"ax\"\n\t" \
- "3: movl %4,%0 ; jmp 1b\n\t" \
- ".previous\n\t" \
- ".section __ex_table,\"a\"\n" \
- " .align 8\n\t" \
- " .quad 2b,3b\n\t" \
- ".previous" \
- : "=a" (ret__) \
- : "c" (msr), "0" (a), "d" (b), "i" (-EFAULT));\
+#define wrmsr_safe(msr,a,b) ({ int ret__; \
+ asm volatile("2: wrmsr ; xorl %0,%0\n" \
+ "1:\n\t" \
+ ".section .fixup,\"ax\"\n\t" \
+ "3: movl %4,%0 ; jmp 1b\n\t" \
+ ".previous\n\t" \
+ ".section __ex_table,\"a\"\n" \
+ " .align 8\n\t" \
+ " .quad 2b,3b\n\t" \
+ ".previous" \
+ : "=a" (ret__) \
+ : "c" (msr), "0" (a), "d" (b), "i" (-EFAULT)); \
ret__; })
#define checking_wrmsrl(msr,val) wrmsr_safe(msr,(u32)(val),(u32)((val)>>32))
+#define rdmsr_safe(msr,a,b) \
+ ({ int ret__; \
+ 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" (ret__), "=a"(a), "=d"(b)\
+ :"c"(msr), "i"(-EIO), "0"(0)); \
+ ret__; })
+
#define rdtsc(low,high) \
__asm__ __volatile__("rdtsc" : "=a" (low), "=d" (high))
projects / platform / kernel / linux-stable.git / commitdiff