Re: [PATCH 2/3] xen: make direct versions ofirq_enable/disable/save/restore to common code

From: Ingo Molnar
Date: Thu Feb 05 2009 - 10:00:53 EST



* Tejun Heo <htejun@xxxxxxxxx> wrote:

> Hello,
>
> Jeremy Fitzhardinge wrote:
> > Now that x86-64 has directly accessible percpu variables, it can also
> > implement the direct versions of these operations, which operate on a
> > vcpu_info structure directly embedded in the percpu area.
> >
> > In fact, the 64-bit versions are more or less identical, and so can be
> > shared. The only two differences are:
> > 1. xen_restore_fl_direct takes its argument in eax on 32-bit, and rdi on
> > 64-bit.
> > Unfortunately it isn't possible to directly refer to the 2nd lsb of
> > rdi directly
> > (as you can with %ah), so the code isn't quite as dense.
> > 2. check_events needs to variants to save different registers.
> >
> > Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
> > ---
> > arch/x86/xen/Makefile | 3 arch/x86/xen/xen-asm.S | 140
> > +++++++++++++++++++++++++++++++++++++++++++++
> > arch/x86/xen/xen-asm.h | 12 +++
> > arch/x86/xen/xen-asm_32.S | 113 ++++--------------------------------
> > arch/x86/xen/xen-asm_64.S | 136
> > +------------------------------------------
> > 5 files changed, 171 insertions(+), 233 deletions(-)
> ...
> > ===================================================================
> > --- a/arch/x86/xen/xen-asm_32.S
> > +++ b/arch/x86/xen/xen-asm_32.S
> > @@ -11,101 +11,28 @@
> > generally too large to inline anyway.
> > */
> >
> > -#include <linux/linkage.h>
> > -
> > -#include <asm/asm-offsets.h>
> > +//#include <asm/asm-offsets.h>
>
> Applied without the above addition of //

btw., that's still worth fixing, plus the comments styles could be
standardized. And this should grow an extra space after the comma:

lea 4(%edi),%esp /* point esp to new frame */

(there's 5-6 similar instructions in that file with this problem - the rest
is fine.)

Ingo
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