From: Brian Gerst Date: Sat, 31 Jul 2010 16:48:22 +0000 (-0400) Subject: x86-64, asm: Directly access per-cpu IST X-Git-Tag: v2.6.36-rc1~526^2~2 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=c15a5958a0b6dbf06b3c05972694f04a0c50a4cf;p=thirdparty%2Fkernel%2Flinux.git x86-64, asm: Directly access per-cpu IST Use a direct per-cpu reference for the IST instead of using a scratch register. Signed-off-by: Brian Gerst LKML-Reference: <1280594903-6341-1-git-send-email-brgerst@gmail.com> Signed-off-by: H. Peter Anvin --- diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index 4db7c4d12ffac..59af275b37a28 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1065,6 +1065,7 @@ ENTRY(\sym) END(\sym) .endm +#define INIT_TSS_IST(x) PER_CPU_VAR(init_tss) + (TSS_ist + ((x) - 1) * 8) .macro paranoidzeroentry_ist sym do_sym ist ENTRY(\sym) INTR_FRAME @@ -1076,10 +1077,9 @@ ENTRY(\sym) TRACE_IRQS_OFF movq %rsp,%rdi /* pt_regs pointer */ xorl %esi,%esi /* no error code */ - PER_CPU(init_tss, %r12) - subq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%r12) + subq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist) call \do_sym - addq $EXCEPTION_STKSZ, TSS_ist + (\ist - 1) * 8(%r12) + addq $EXCEPTION_STKSZ, INIT_TSS_IST(\ist) jmp paranoid_exit /* %ebx: no swapgs flag */ CFI_ENDPROC END(\sym)