Merge branch 'hwmon-for-linus' of git://jdelvare.pck.nerim.net/jdelvare-2.6

[pandora-kernel.git] / arch / x86_64 / kernel / head.S

diff --git a/arch/x86_64/kernel/head.S b/arch/x86_64/kernel/head.S
index c9739ca..598a4d0 100644 (file)
--- a/arch/x86_64/kernel/head.S
+++ b/arch/x86_64/kernel/head.S
@@ -5,8 +5,6 @@
  *  Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
  *  Copyright (C) 2000 Karsten Keil <kkeil@suse.de>
  *  Copyright (C) 2001,2002 Andi Kleen <ak@suse.de>
- *
- *  $Id: head.S,v 1.49 2002/03/19 17:39:25 ak Exp $
  */
 
 
@@ -165,6 +163,20 @@ startup_64:
         */
        lgdt    cpu_gdt_descr
 
+       /* set up data segments. actually 0 would do too */
+       movl $__KERNEL_DS,%eax
+       movl %eax,%ds
+       movl %eax,%ss
+       movl %eax,%es
+
+       /*
+        * We don't really need to load %fs or %gs, but load them anyway
+        * to kill any stale realmode selectors.  This allows execution
+        * under VT hardware.
+        */
+       movl %eax,%fs
+       movl %eax,%gs
+
        /* 
         * Setup up a dummy PDA. this is just for some early bootup code
         * that does in_interrupt() 
@@ -175,24 +187,21 @@ startup_64:
        shrq    $32,%rdx
        wrmsr   
 
-       /* set up data segments. actually 0 would do too */
-       movl $__KERNEL_DS,%eax
-       movl %eax,%ds   
-       movl %eax,%ss
-       movl %eax,%es
-                       
        /* esi is pointer to real mode structure with interesting info.
           pass it to C */
        movl    %esi, %edi
        
        /* Finally jump to run C code and to be on real kernel address
         * Since we are running on identity-mapped space we have to jump
-        * to the full 64bit address , this is only possible as indirect
-        * jump
+        * to the full 64bit address, this is only possible as indirect
+        * jump.  In addition we need to ensure %cs is set so we make this
+        * a far return.
         */
        movq    initial_code(%rip),%rax
-       pushq   $0              # fake return address
-       jmp     *%rax
+       pushq   $0              # fake return address to stop unwinder
+       pushq   $__KERNEL_CS    # set correct cs
+       pushq   %rax            # target address in negative space
+       lretq
 
        /* SMP bootup changes these two */
        .align  8
@@ -371,7 +380,7 @@ ENTRY(cpu_gdt_table)
        .quad   0,0                     /* TSS */
        .quad   0,0                     /* LDT */
        .quad   0,0,0                   /* three TLS descriptors */ 
-       .quad   0                       /* unused */
+       .quad   0x0000f40000000000      /* node/CPU stored in limit */
 gdt_end:       
        /* asm/segment.h:GDT_ENTRIES must match this */ 
        /* This should be a multiple of the cache line size */