[PATCH] i386: inline assembler: cleanup and encapsulate descriptor and task register management

i386 inline assembler cleanup.

This change encapsulates descriptor and task register management.  Also,
it is possible to improve assembler generation in two cases; savesegment
may store the value in a register instead of a memory location, which
allows GCC to optimize stack variables into registers, and MOV MEM, SEG
is always a 16-bit write to memory, making the casting in math-emu
unnecessary.

Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 5 insertions, 4 deletions

diff --git a/arch/i386/kernel/reboot.c b/arch/i386/kernel/reboot.c
index c71fef31dc47..1cbb9c0f4704 100644
--- a/arch/i386/kernel/reboot.c
+++ b/arch/i386/kernel/reboot.c
@@ -13,6 +13,7 @@
 #include <linux/dmi.h>
 #include <asm/uaccess.h>
 #include <asm/apic.h>
+#include <asm/desc.h>
 #include "mach_reboot.h"
 #include <linux/reboot_fixups.h>
 
@@ -242,13 +243,13 @@ void machine_real_restart(unsigned char *code, int length)
 
         /* Set up the IDT for real mode. */
 
-        __asm__ __volatile__ ("lidt %0" : : "m" (real_mode_idt));
+        load_idt(&real_mode_idt);
 
         /* Set up a GDT from which we can load segment descriptors for real
            mode.  The GDT is not used in real mode; it is just needed here to
            prepare the descriptors. */
 
-        __asm__ __volatile__ ("lgdt %0" : : "m" (real_mode_gdt));
+        load_gdt(&real_mode_gdt);
 
         /* Load the data segment registers, and thus the descriptors ready for
            real mode.  The base address of each segment is 0x100, 16 times the
@@ -316,7 +317,7 @@ void machine_emergency_restart(void)
         if (!reboot_thru_bios) {
                 if (efi_enabled) {
                         efi.reset_system(EFI_RESET_COLD, EFI_SUCCESS, 0, NULL);
-                        __asm__ __volatile__("lidt %0": :"m" (no_idt));
+                        load_idt(&no_idt);
                         __asm__ __volatile__("int3");
                 }
                 /* rebooting needs to touch the page at absolute addr 0 */
@@ -325,7 +326,7 @@ void machine_emergency_restart(void)
                         mach_reboot_fixups(); /* for board specific fixups */
                         mach_reboot();
                         /* That didn't work - force a triple fault.. */
-                        __asm__ __volatile__("lidt %0": :"m" (no_idt));
+                        load_idt(&no_idt);
                         __asm__ __volatile__("int3");
                 }
         }