Merge to Fedora kernel-2.6.7-1.492

[linux-2.6.git] / arch / s390 / mm / cmm.c

diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
index 095a564..72d4f1e 100644 (file)
--- a/arch/s390/mm/cmm.c
+++ b/arch/s390/mm/cmm.c
@@ -407,6 +407,14 @@ struct ctl_table_header *cmm_sysctl_header;
 static int
 cmm_init (void)
 {
+       int rc;
+
+       /* Prevent logical cpu 0 from being set offline. */
+       rc = smp_get_cpu(cpumask_of_cpu(0));
+       if (rc) {
+               printk(KERN_ERR "CMM: unable to reserve cpu 0\n");
+               return rc;
+       }
 #ifdef CONFIG_CMM_PROC
        cmm_sysctl_header = register_sysctl_table(cmm_dir_table, 1);
 #endif
@@ -430,6 +438,8 @@ cmm_exit(void)
 #ifdef CONFIG_CMM_IUCV
        smsg_unregister_callback(SMSG_PREFIX, cmm_smsg_target);
 #endif
+       /* Allow logical cpu 0 to be set offline again. */
+       smp_put_cpu(0);
 }
 
 module_init(cmm_init);