From: Suresh Siddha <suresh.b.siddha@intel.com>
Date: Tue, 29 Jul 2008 17:29:20 +0000 (-0700)
Subject: x86, xsave: context switch support using xsave/xrstor
X-Git-Tag: v2.6.28-rc1~699^2^8~20
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b359e8a434cc3d09847010fc4aeccf48d69740e4;p=pandora-kernel.git

x86, xsave: context switch support using xsave/xrstor

Uses xsave/xrstor (instead of traditional fxsave/fxrstor) in context switch
when available.

Introduces TS_XSAVE flag, which determine the need to use xsave/xrstor
instructions during context switch instead of the legacy fxsave/fxrstor
instructions. Thread-synchronous status word is already in L1 cache during
this code patch and thus minimizes the performance penality compared to
(cpu_has_xsave) checks.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
---

Reading git-diff-tree failed