From 6617927031e114268a66bbfc906340f3ec060aeb Mon Sep 17 00:00:00 2001
From: Chuck Ebbert <76306.1226@compuserve.com>
Date: Thu, 23 Mar 2006 02:59:34 -0800
Subject: [PATCH] --- yaml --- r: 22987 b: refs/heads/master c:
 4f88651125e2ca8b106b6f65b65ea45776517bf3 h: refs/heads/master i:   22985:
 8ddf67849b3185d06d0d7791c5d423ea3d175387   22983:
 36a8c51ca349762aca1a98b31b5993503d1ef7fb v: v3

---
 [refs]                                    |  2 +-
 trunk/Documentation/kernel-parameters.txt |  6 +++++-
 trunk/arch/i386/kernel/cpu/common.c       | 15 ++++++++++++++-
 3 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/[refs] b/[refs]
index dcffbcaa287a..45847c213798 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 3bc9b76bede9b3c72088258c7e72eb823f3351d4
+refs/heads/master: 4f88651125e2ca8b106b6f65b65ea45776517bf3
diff --git a/trunk/Documentation/kernel-parameters.txt b/trunk/Documentation/kernel-parameters.txt
index fc99075e0af4..880be3a30d8d 100644
--- a/trunk/Documentation/kernel-parameters.txt
+++ b/trunk/Documentation/kernel-parameters.txt
@@ -1008,7 +1008,9 @@ running once the system is up.
 			noexec=on: enable non-executable mappings (default)
 			noexec=off: disable nn-executable mappings
 
-	nofxsr		[BUGS=IA-32]
+	nofxsr		[BUGS=IA-32] Disables x86 floating point extended
+			register save and restore. The kernel will only save
+			legacy floating-point registers on task switch.
 
 	nohlt		[BUGS=ARM]
 
@@ -1053,6 +1055,8 @@ running once the system is up.
 
 	nosbagart	[IA-64]
 
+	nosep		[BUGS=IA-32] Disables x86 SYSENTER/SYSEXIT support.
+
 	nosmp		[SMP] Tells an SMP kernel to act as a UP kernel.
 
 	nosync		[HW,M68K] Disables sync negotiation for all devices.
diff --git a/trunk/arch/i386/kernel/cpu/common.c b/trunk/arch/i386/kernel/cpu/common.c
index f63dcfb16dad..bbfc278dfa49 100644
--- a/trunk/arch/i386/kernel/cpu/common.c
+++ b/trunk/arch/i386/kernel/cpu/common.c
@@ -26,8 +26,9 @@ DEFINE_PER_CPU(unsigned char, cpu_16bit_stack[CPU_16BIT_STACK_SIZE]);
 EXPORT_PER_CPU_SYMBOL(cpu_16bit_stack);
 
 static int cachesize_override __cpuinitdata = -1;
-static int disable_x86_fxsr __cpuinitdata = 0;
+static int disable_x86_fxsr __cpuinitdata;
 static int disable_x86_serial_nr __cpuinitdata = 1;
+static int disable_x86_sep __cpuinitdata;
 
 struct cpu_dev * cpu_devs[X86_VENDOR_NUM] = {};
 
@@ -187,6 +188,14 @@ static int __init x86_fxsr_setup(char * s)
 __setup("nofxsr", x86_fxsr_setup);
 
 
+static int __init x86_sep_setup(char * s)
+{
+	disable_x86_sep = 1;
+	return 1;
+}
+__setup("nosep", x86_sep_setup);
+
+
 /* Standard macro to see if a specific flag is changeable */
 static inline int flag_is_changeable_p(u32 flag)
 {
@@ -405,6 +414,10 @@ void __cpuinit identify_cpu(struct cpuinfo_x86 *c)
 		clear_bit(X86_FEATURE_XMM, c->x86_capability);
 	}
 
+	/* SEP disabled? */
+	if (disable_x86_sep)
+		clear_bit(X86_FEATURE_SEP, c->x86_capability);
+
 	if (disable_pse)
 		clear_bit(X86_FEATURE_PSE, c->x86_capability);