x86: cpuid, msr: use inode mutex instead of big kernel lock

[linux-2.6-omap-h63xx.git] / arch / x86 / kernel / cpuid.c

diff --git a/arch/x86/kernel/cpuid.c b/arch/x86/kernel/cpuid.c
index 70dcf912d9fb3076e1116a438a3dcde699205ab9..288e7a6598ac6450c1b13a88e51337ccc0c0b9d2 100644 (file)
--- a/arch/x86/kernel/cpuid.c
+++ b/arch/x86/kernel/cpuid.c
@@ -1,6 +1,6 @@
 /* ----------------------------------------------------------------------- *
- *   
- *   Copyright 2000 H. Peter Anvin - All Rights Reserved
+ *
+ *   Copyright 2000-2008 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
@@ -17,6 +17,10 @@
  * and then read in chunks of 16 bytes.  A larger size means multiple
  * reads of consecutive levels.
  *
+ * The lower 32 bits of the file position is used as the incoming %eax,
+ * and the upper 32 bits of the file position as the incoming %ecx,
+ * the latter intended for "counting" eax levels like eax=4.
+ *
  * This driver uses /dev/cpu/%d/cpuid where %d is the minor number, and on
  * an SMP box will direct the access to CPU %d.
  */
@@ -43,35 +47,24 @@
 
 static struct class *cpuid_class;
 
-struct cpuid_command {
-       u32 reg;
-       u32 *data;
+struct cpuid_regs {
+       u32 eax, ebx, ecx, edx;
 };
 
 static void cpuid_smp_cpuid(void *cmd_block)
 {
-       struct cpuid_command *cmd = (struct cpuid_command *)cmd_block;
+       struct cpuid_regs *cmd = (struct cpuid_regs *)cmd_block;
 
-       cpuid(cmd->reg, &cmd->data[0], &cmd->data[1], &cmd->data[2],
-                     &cmd->data[3]);
-}
-
-static inline void do_cpuid(int cpu, u32 reg, u32 * data)
-{
-       struct cpuid_command cmd;
-
-       cmd.reg = reg;
-       cmd.data = data;
-
-       smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1, 1);
+       cpuid_count(cmd->eax, cmd->ecx,
+                   &cmd->eax, &cmd->ebx, &cmd->ecx, &cmd->edx);
 }
 
 static loff_t cpuid_seek(struct file *file, loff_t offset, int orig)
 {
        loff_t ret;
+       struct inode *inode = file->f_mapping->host;
 
-       lock_kernel();
-
+       mutex_lock(&inode->i_mutex);
        switch (orig) {
        case 0:
                file->f_pos = offset;
@@ -84,8 +77,7 @@ static loff_t cpuid_seek(struct file *file, loff_t offset, int orig)
        default:
                ret = -EINVAL;
        }
-
-       unlock_kernel();
+       mutex_unlock(&inode->i_mutex);
        return ret;
 }
 
@@ -93,19 +85,21 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
                          size_t count, loff_t * ppos)
 {
        char __user *tmp = buf;
-       u32 data[4];
-       u32 reg = *ppos;
+       struct cpuid_regs cmd;
        int cpu = iminor(file->f_path.dentry->d_inode);
+       u64 pos = *ppos;
 
        if (count % 16)
                return -EINVAL; /* Invalid chunk size */
 
        for (; count; count -= 16) {
-               do_cpuid(cpu, reg, data);
-               if (copy_to_user(tmp, &data, 16))
+               cmd.eax = pos;
+               cmd.ecx = pos >> 32;
+               smp_call_function_single(cpu, cpuid_smp_cpuid, &cmd, 1, 1);
+               if (copy_to_user(tmp, &cmd, 16))
                        return -EFAULT;
                tmp += 16;
-               *ppos = reg++;
+               *ppos = ++pos;
        }
 
        return tmp - buf;
@@ -114,7 +108,7 @@ static ssize_t cpuid_read(struct file *file, char __user *buf,
 static int cpuid_open(struct inode *inode, struct file *file)
 {
        unsigned int cpu = iminor(file->f_path.dentry->d_inode);
-       struct cpuinfo_x86 *c = &(cpu_data)[cpu];
+       struct cpuinfo_x86 *c = &cpu_data(cpu);
 
        if (cpu >= NR_CPUS || !cpu_online(cpu))
                return -ENXIO;  /* No such CPU */
@@ -134,15 +128,18 @@ static const struct file_operations cpuid_fops = {
        .open = cpuid_open,
 };
 
-static int __cpuinit cpuid_device_create(int i)
+static __cpuinit int cpuid_device_create(int cpu)
 {
-       int err = 0;
        struct device *dev;
 
-       dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, i), "cpu%d",i);
-       if (IS_ERR(dev))
-               err = PTR_ERR(dev);
-       return err;
+       dev = device_create(cpuid_class, NULL, MKDEV(CPUID_MAJOR, cpu),
+                           "cpu%d", cpu);
+       return IS_ERR(dev) ? PTR_ERR(dev) : 0;
+}
+
+static void cpuid_device_destroy(int cpu)
+{
+       device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
 }
 
 static int __cpuinit cpuid_class_cpu_callback(struct notifier_block *nfb,
@@ -150,21 +147,24 @@ static int __cpuinit cpuid_class_cpu_callback(struct notifier_block *nfb,
                                              void *hcpu)
 {
        unsigned int cpu = (unsigned long)hcpu;
+       int err = 0;
 
        switch (action) {
-       case CPU_ONLINE:
-       case CPU_ONLINE_FROZEN:
-               cpuid_device_create(cpu);
+       case CPU_UP_PREPARE:
+               err = cpuid_device_create(cpu);
                break;
+       case CPU_UP_CANCELED:
        case CPU_DEAD:
-       case CPU_DEAD_FROZEN:
-               device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
+               cpuid_device_destroy(cpu);
+               break;
+       case CPU_UP_CANCELED_FROZEN:
+               destroy_suspended_device(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
                break;
        }
-       return NOTIFY_OK;
+       return err ? NOTIFY_BAD : NOTIFY_OK;
 }
 
-static struct notifier_block __cpuinitdata cpuid_class_cpu_notifier =
+static struct notifier_block __refdata cpuid_class_cpu_notifier =
 {
        .notifier_call = cpuid_class_cpu_callback,
 };
@@ -187,7 +187,7 @@ static int __init cpuid_init(void)
        }
        for_each_online_cpu(i) {
                err = cpuid_device_create(i);
-               if (err != 0) 
+               if (err != 0)
                        goto out_class;
        }
        register_hotcpu_notifier(&cpuid_class_cpu_notifier);
@@ -198,11 +198,11 @@ static int __init cpuid_init(void)
 out_class:
        i = 0;
        for_each_online_cpu(i) {
-               device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, i));
+               cpuid_device_destroy(i);
        }
        class_destroy(cpuid_class);
 out_chrdev:
-       unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");    
+       unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");
 out:
        return err;
 }
@@ -212,7 +212,7 @@ static void __exit cpuid_exit(void)
        int cpu = 0;
 
        for_each_online_cpu(cpu)
-               device_destroy(cpuid_class, MKDEV(CPUID_MAJOR, cpu));
+               cpuid_device_destroy(cpu);
        class_destroy(cpuid_class);
        unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");
        unregister_hotcpu_notifier(&cpuid_class_cpu_notifier);