Driver-Core: extend devnode callbacks to provide permissions

[deliverable/linux.git] / arch / x86 / kernel / msr.c

diff --git a/arch/x86/kernel/msr.c b/arch/x86/kernel/msr.c
index 98fd6cd4e3a479e8e1cea7a4ccfad7063f921850..6a3cefc7dda1ecdfc17315624fbde11366670fb7 100644 (file)
--- 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
@@ -80,11 +81,8 @@ static ssize_t msr_read(struct file *file, char __user *buf,
 
        for (; count; count -= 8) {
                err = rdmsr_safe_on_cpu(cpu, reg, &data[0], &data[1]);
-               if (err) {
-                       if (err == -EFAULT) /* Fix idiotic error code */
-                               err = -EIO;
+               if (err)
                        break;
-               }
                if (copy_to_user(tmp, &data, 8)) {
                        err = -EFAULT;
                        break;
@@ -115,11 +113,8 @@ static ssize_t msr_write(struct file *file, const char __user *buf,
                        break;
                }
                err = wrmsr_safe_on_cpu(cpu, reg, data[0], data[1]);
-               if (err) {
-                       if (err == -EFAULT) /* Fix idiotic error code */
-                               err = -EIO;
+               if (err)
                        break;
-               }
                tmp += 2;
                bytes += 8;
        }
@@ -127,6 +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);
@@ -157,6 +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)
@@ -196,7 +241,7 @@ static struct notifier_block __refdata msr_class_cpu_notifier = {
        .notifier_call = msr_class_cpu_callback,
 };
 
-static char *msr_nodename(struct device *dev)
+static char *msr_devnode(struct device *dev, mode_t *mode)
 {
        return kasprintf(GFP_KERNEL, "cpu/%u/msr", MINOR(dev->devt));
 }
@@ -217,7 +262,7 @@ static int __init msr_init(void)
                err = PTR_ERR(msr_class);
                goto out_chrdev;
        }
-       msr_class->nodename = msr_nodename;
+       msr_class->devnode = msr_devnode;
        for_each_online_cpu(i) {
                err = msr_device_create(i);
                if (err != 0)