[PATCH] port of cpuid to devfs

[Duncan Sands <sands@xxxxxxxxxxxxxxxxxxx>]

I ported cpuid for kernel version 2.4.2 to devfs.  It now creates
the /dev/cpu/%d/cpuid devices.  The changes are straightforward.

Duncan Sands.

--- arch/i386/kernel/cpuid.c.orig       Mon Mar 19 17:57:24 2001
+++ arch/i386/kernel/cpuid.c    Mon Mar 19 16:13:14 2001
@@ -35,12 +35,15 @@
 #include <linux/poll.h>
 #include <linux/smp.h>
 #include <linux/major.h>
+#include <linux/devfs_fs_kernel.h>
 
 #include <asm/processor.h>
 #include <asm/msr.h>
 #include <asm/uaccess.h>
 #include <asm/system.h>
 
+static devfs_handle_t dir_handle;      /*  For the directory */
+
 #ifdef CONFIG_SMP
 
 struct cpuid_command {
@@ -142,18 +145,38 @@
 
 int __init cpuid_init(void)
 {
-  if (register_chrdev(CPUID_MAJOR, "cpu/cpuid", &cpuid_fops)) {
+  if (devfs_register_chrdev(CPUID_MAJOR, "cpu/cpuid", &cpuid_fops)) {
     printk(KERN_ERR "cpuid: unable to get major %d for cpuid\n",
           CPUID_MAJOR);
     return -EBUSY;
   }
 
+  dir_handle = devfs_mk_dir(NULL, "cpu", NULL);
+  devfs_register_series(dir_handle, "%u/cpuid", smp_num_cpus, DEVFS_FL_DEFAULT,
+                        CPUID_MAJOR, 0,
+                        S_IFCHR | S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH,
+                        &cpuid_fops, NULL);
+
   return 0;
 }
 
 void __exit cpuid_exit(void)
 {
-  unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");
+  char devname[16];
+  devfs_handle_t handle;
+  unsigned int minor;
+
+#ifdef CONFIG_DEVFS_FS
+  for (minor=0; minor < smp_num_cpus; ++minor)
+  {
+    sprintf(devname, "%u/cpuid", minor);
+    handle = devfs_find_handle(dir_handle, devname, CPUID_MAJOR, minor,
+                               DEVFS_SPECIAL_CHR, 0);
+    devfs_unregister(handle);
+  }
+#endif /* CONFIG_DEVFS_FS */
+
+  devfs_unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");
 }
 
 module_init(cpuid_init);