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

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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>
This commit is contained in:
Zachary Amsden
2005-09-03 15:56:38 -07:00
committed by Linus Torvalds
parent 245067d167
commit 4d37e7e3fd
11 changed files with 43 additions and 40 deletions
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4
arch/i386/kernel/vm86.c
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@@ -294,8 +294,8 @@ static void do_sys_vm86(struct kernel_vm86_struct *info, struct task_struct *tsk
*/
info->regs32->eax = 0;
tsk->thread.saved_esp0 = tsk->thread.esp0;
asm volatile("mov %%fs,%0":"=m" (tsk->thread.saved_fs));
asm volatile("mov %%gs,%0":"=m" (tsk->thread.saved_gs));
savesegment(fs, tsk->thread.saved_fs);
savesegment(gs, tsk->thread.saved_gs);
tss = &per_cpu(init_tss, get_cpu());
tsk->thread.esp0 = (unsigned long) &info->VM86_TSS_ESP0;