1 files changed, 8 insertions, 3 deletions

diff --git a/arch/i386/kernel/apm.c b/arch/i386/kernel/apm.c
index a60358fe9a49..199016927541 100644
--- a/arch/i386/kernel/apm.c
+++ b/arch/i386/kernel/apm.c
@@ -231,6 +231,7 @@
 #include <asm/uaccess.h>
 #include <asm/desc.h>
 #include <asm/i8253.h>
+#include <asm/paravirt.h>
 
 #include "io_ports.h"
 
@@ -784,7 +785,11 @@ static int apm_do_idle(void)
         polling = !!(current_thread_info()->status & TS_POLLING);
         if (polling) {
                 current_thread_info()->status &= ~TS_POLLING;
-                smp_mb__after_clear_bit();
+                /*
+                 * TS_POLLING-cleared state must be visible before we
+                 * test NEED_RESCHED:
+                 */
+                smp_mb();
         }
         if (!need_resched()) {
                 idled = 1;
@@ -1603,7 +1608,7 @@ static int do_open(struct inode * inode, struct file * filp)
 {
         struct apm_user *       as;
 
-        as = (struct apm_user *)kmalloc(sizeof(*as), GFP_KERNEL);
+        as = kmalloc(sizeof(*as), GFP_KERNEL);
         if (as == NULL) {
                 printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
                        sizeof(*as));
@@ -2235,7 +2240,7 @@ static int __init apm_init(void)
 
         dmi_check_system(apm_dmi_table);
 
-        if (apm_info.bios.version == 0) {
+        if (apm_info.bios.version == 0 || paravirt_enabled()) {
                 printk(KERN_INFO "apm: BIOS not found.\n");
                 return -ENODEV;
         }