patch-2_6_7-vs1_9_1_12
[linux-2.6.git] / arch / ia64 / kernel / palinfo.c
index 27123bb..fab4296 100644 (file)
@@ -8,11 +8,14 @@
  *
  * Copyright (C) 2000-2001, 2003 Hewlett-Packard Co
  *     Stephane Eranian <eranian@hpl.hp.com>
+ * Copyright (C) 2004 Intel Corporation
+ *  Ashok Raj <ashok.raj@intel.com>
  *
  * 05/26/2000  S.Eranian       initial release
  * 08/21/2000  S.Eranian       updated to July 2000 PAL specs
  * 02/05/2001   S.Eranian      fixed module support
  * 10/23/2001  S.Eranian       updated pal_perf_mon_info bug fixes
+ * 03/24/2004  Ashok Raj       updated to work with CPU Hotplug
  */
 #include <linux/config.h>
 #include <linux/types.h>
@@ -22,6 +25,9 @@
 #include <linux/mm.h>
 #include <linux/module.h>
 #include <linux/efi.h>
+#include <linux/notifier.h>
+#include <linux/cpu.h>
+#include <linux/cpumask.h>
 
 #include <asm/pal.h>
 #include <asm/sal.h>
@@ -768,13 +774,12 @@ static palinfo_entry_t palinfo_entries[]={
  * does not do recursion of deletion
  *
  * Notes:
- *     - first +1 accounts for the cpuN entry
- *     - second +1 account for toplevel palinfo
- *
+ *     - +1 accounts for the cpuN directory entry in /proc/pal
  */
-#define NR_PALINFO_PROC_ENTRIES        (NR_CPUS*(NR_PALINFO_ENTRIES+1)+1)
+#define NR_PALINFO_PROC_ENTRIES        (NR_CPUS*(NR_PALINFO_ENTRIES+1))
 
 static struct proc_dir_entry *palinfo_proc_entries[NR_PALINFO_PROC_ENTRIES];
+static struct proc_dir_entry *palinfo_dir;
 
 /*
  * This data structure is used to pass which cpu,function is being requested
@@ -888,47 +893,107 @@ palinfo_read_entry(char *page, char **start, off_t off, int count, int *eof, voi
        return len;
 }
 
-static int __init
-palinfo_init(void)
+static void
+create_palinfo_proc_entries(unsigned int cpu)
 {
 #      define CPUSTR   "cpu%d"
 
        pal_func_cpu_u_t f;
-       struct proc_dir_entry **pdir = palinfo_proc_entries;
-       struct proc_dir_entry *palinfo_dir, *cpu_dir;
-       int i, j;
+       struct proc_dir_entry **pdir;
+       struct proc_dir_entry *cpu_dir;
+       int j;
        char cpustr[sizeof(CPUSTR)];
 
-       printk(KERN_INFO "PAL Information Facility v%s\n", PALINFO_VERSION);
-
-       palinfo_dir = proc_mkdir("pal", NULL);
 
        /*
         * we keep track of created entries in a depth-first order for
         * cleanup purposes. Each entry is stored into palinfo_proc_entries
         */
-       for (i=0; i < NR_CPUS; i++) {
-
-               if (!cpu_online(i)) continue;
+       sprintf(cpustr,CPUSTR, cpu);
 
-               sprintf(cpustr,CPUSTR, i);
+       cpu_dir = proc_mkdir(cpustr, palinfo_dir);
 
-               cpu_dir = proc_mkdir(cpustr, palinfo_dir);
+       f.req_cpu = cpu;
 
-               f.req_cpu = i;
+       /*
+        * Compute the location to store per cpu entries
+        * We dont store the top level entry in this list, but
+        * remove it finally after removing all cpu entries.
+        */
+       pdir = &palinfo_proc_entries[cpu*(NR_PALINFO_ENTRIES+1)];
+       *pdir++ = cpu_dir;
+       for (j=0; j < NR_PALINFO_ENTRIES; j++) {
+               f.func_id = j;
+               *pdir = create_proc_read_entry(
+                               palinfo_entries[j].name, 0, cpu_dir,
+                               palinfo_read_entry, (void *)f.value);
+               if (*pdir)
+                       (*pdir)->owner = THIS_MODULE;
+               pdir++;
+       }
+}
 
-               for (j=0; j < NR_PALINFO_ENTRIES; j++) {
-                       f.func_id = j;
-                       *pdir = create_proc_read_entry(
-                                       palinfo_entries[j].name, 0, cpu_dir,
-                                       palinfo_read_entry, (void *)f.value);
-                       if (*pdir)
-                               (*pdir)->owner = THIS_MODULE;
-                       pdir++;
+static void
+remove_palinfo_proc_entries(unsigned int hcpu)
+{
+       int j;
+       struct proc_dir_entry *cpu_dir, **pdir;
+
+       pdir = &palinfo_proc_entries[hcpu*(NR_PALINFO_ENTRIES+1)];
+       cpu_dir = *pdir;
+       *pdir++=NULL;
+       for (j=0; j < (NR_PALINFO_ENTRIES); j++) {
+               if ((*pdir)) {
+                       remove_proc_entry ((*pdir)->name, cpu_dir);
+                       *pdir ++= NULL;
                }
-               *pdir++ = cpu_dir;
        }
-       *pdir = palinfo_dir;
+
+       if (cpu_dir) {
+               remove_proc_entry(cpu_dir->name, palinfo_dir);
+       }
+}
+
+static int __devinit palinfo_cpu_callback(struct notifier_block *nfb,
+                                                               unsigned long action,
+                                                               void *hcpu)
+{
+       unsigned int hotcpu = (unsigned long)hcpu;
+
+       switch (action) {
+       case CPU_ONLINE:
+               create_palinfo_proc_entries(hotcpu);
+               break;
+#ifdef CONFIG_HOTPLUG_CPU
+       case CPU_DEAD:
+               remove_palinfo_proc_entries(hotcpu);
+               break;
+#endif
+       }
+       return NOTIFY_OK;
+}
+
+static struct notifier_block palinfo_cpu_notifier =
+{
+       .notifier_call = palinfo_cpu_callback,
+       .priority = 0,
+};
+
+static int __init
+palinfo_init(void)
+{
+       int i = 0;
+
+       printk(KERN_INFO "PAL Information Facility v%s\n", PALINFO_VERSION);
+       palinfo_dir = proc_mkdir("pal", NULL);
+
+       /* Create palinfo dirs in /proc for all online cpus */
+       for_each_online_cpu(i) {
+               create_palinfo_proc_entries(i);
+       }
+
+       /* Register for future delivery via notify registration */
+       register_cpu_notifier(&palinfo_cpu_notifier);
 
        return 0;
 }
@@ -939,10 +1004,19 @@ palinfo_exit(void)
        int i = 0;
 
        /* remove all nodes: depth first pass. Could optimize this  */
-       for (i=0; i< NR_PALINFO_PROC_ENTRIES ; i++) {
-               if (palinfo_proc_entries[i])
-                       remove_proc_entry (palinfo_proc_entries[i]->name, NULL);
+       for_each_online_cpu(i) {
+               remove_palinfo_proc_entries(i);
        }
+
+       /*
+        * Remove the top level entry finally
+        */
+       remove_proc_entry(palinfo_dir->name, NULL);
+
+       /*
+        * Unregister from cpu notifier callbacks
+        */
+       unregister_cpu_notifier(&palinfo_cpu_notifier);
 }
 
 module_init(palinfo_init);