Utility functions to handle /dev/cpu/

@@ -924,6 +924,25 @@ void devfs_put (devfs_handle_t de)
 }   /*  End Function devfs_put  */
 
 /**
+ * 	_devfs_update_dev_cpu - Update the /dev/cpu/ hierarchy
+ * 
+ *  This function should be updated when/if CPU Hotplugging support is added
+ *   so that plugging in/out a CPU will be reflected in the /dev/cpu/ 
+ *   hierarchy.
+ */
+
+void _devfs_update_dev_cpu (void)
+{
+    int tmp;
+    for (tmp = 0; tmp < smp_num_cpus; tmp++)
+    {
+        char path[8];
+        sprintf (path, "cpu/%d", tmp);
+        devfs_mk_dir (NULL, path, NULL);
+    }
+}   /* End Function _devfs_update_dev_cpu */
+
+/**
  *	_devfs_search_dir - Search for a devfs entry in a directory.
  *	@dir:  The directory to search.
  *	@name:  The name of the entry to search for.

@@ -3466,7 +3485,6 @@ static ssize_t stat_read (struct file *f
 }   /*  End Function stat_read  */
 #endif
 
-
 static int __init init_devfs_fs (void)
 {
     int err;

@@ -3500,6 +3518,9 @@ void __init mount_devfs_fs (void)
     err = do_mount ("none", "/dev", "devfs", 0, "");
     if (err == 0) printk (KERN_INFO "Mounted devfs on /dev\n");
     else PRINTK ("(): unable to mount devfs, err: %d\n", err);
+
+    _devfs_update_dev_cpu ();
+
 }   /*  End Function mount_devfs_fs  */
 
 module_init(init_devfs_fs)

56 lines not on this page · raw message

@@ -107,6 +107,11 @@ extern void devfs_register_series (devfs
 				   unsigned int flags, unsigned int major,
 				   unsigned int minor_start,
 				   umode_t mode, void *ops, void *info);
+extern void devfs_per_cpu_register (const char *name, unsigned int flags,
+				    unsigned int major, 
+				    unsigned int minor_start, umode_t mode,
+				    void *ops, void *info);
+extern void devfs_per_cpu_unregister (const char *name);
 extern int devfs_alloc_major (char type);
 extern void devfs_dealloc_major (char type, int major);
 extern kdev_t devfs_alloc_devnum (char type);

@@ -272,6 +277,19 @@ static inline void devfs_register_series
 					  unsigned int major,
 					  unsigned int minor_start,
 					  umode_t mode, void *ops, void *info)
+{
+    return;
+}
+static inline void devfs_per_cpu_register (const char *name,
+					   unsigned int flags,
+					   unsigned int major,
+					   unsigned int minor_start,
+					   umode_t mode, void *ops, void *info)
+{
+    return;
+}
+
+static inline void devfs_per_cpu_unregister (const char *name);
 {
     return;
 }

@@ -34,6 +34,7 @@
 #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>

@@ -250,18 +251,26 @@ static struct file_operations msr_fops =
 
 int __init msr_init(void)
 {
+#ifndef CONFIG_DEVFS_FS
   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;
   }
-  
+#else
+  devfs_per_cpu_register("msr", DEVFS_FL_DEFAULT, 202, 0,
+			S_IFCHR | S_IRUSR | S_IWUSR, &msr_fops, NULL);
+#endif
   return 0;
 }
 
 void __exit msr_exit(void)
 {
+#ifndef CONFIG_DEVFS_FS
   unregister_chrdev(MSR_MAJOR, "cpu/msr");
+#else
+  devfs_per_cpu_unregister("msr");
+#endif
 }
 
 module_init(msr_init);

@@ -35,6 +35,7 @@
 #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>

@@ -142,18 +143,26 @@ static struct file_operations cpuid_fops
 
 int __init cpuid_init(void)
 {
+#ifndef CONFIG_DEVFS_FS
   if (register_chrdev(CPUID_MAJOR, "cpu/cpuid", &cpuid_fops)) {
     printk(KERN_ERR "cpuid: unable to get major %d for cpuid\n",
 	   CPUID_MAJOR);
     return -EBUSY;
   }
-
+#else
+  devfs_per_cpu_register("cpuid", DEVFS_FL_DEFAULT, 203, 0, 
+			S_IFCHR | S_IRUSR | S_IWUSR, &cpuid_fops, NULL);
+#endif
   return 0;
 }
 
 void __exit cpuid_exit(void)
 {
+#ifndef CONFIG_DEVFS_FS
   unregister_chrdev(CPUID_MAJOR, "cpu/cpuid");
+#else
+  devfs_per_cpu_unregister("cpuid");
+#endif
 }
 
 module_init(cpuid_init);