[patch 1/2] F00F bug fixup for i386 - use immediate values

[Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>]

Use the faster immediate values for F00F bug handling in do_page_fault.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
---
 arch/i386/kernel/traps.c     |    4 ++++
 arch/i386/mm/fault.c         |    3 ++-
 include/asm-i386/processor.h |    3 +++
 3 files changed, 9 insertions(+), 1 deletion(-)

Index: linux-2.6-lttng/arch/i386/kernel/traps.c
===================================================================
--- linux-2.6-lttng.orig/arch/i386/kernel/traps.c	2007-07-13 19:30:53.000000000 -0400
+++ linux-2.6-lttng/arch/i386/kernel/traps.c	2007-07-13 19:31:21.000000000 -0400
@@ -31,6 +31,7 @@
 #include <linux/uaccess.h>
 #include <linux/nmi.h>
 #include <linux/bug.h>
+#include <linux/immediate.h>
 
 #ifdef CONFIG_EISA
 #include <linux/ioport.h>
@@ -1158,6 +1159,8 @@
 #endif /* CONFIG_MATH_EMULATION */
 
 #ifdef CONFIG_X86_F00F_BUG
+immediate_char_t f00f_bug_fix __read_mostly;
+
 void __init trap_init_f00f_bug(void)
 {
 	__set_fixmap(FIX_F00F_IDT, __pa(&idt_table), PAGE_KERNEL_RO);
@@ -1168,6 +1171,7 @@
 	 */
 	idt_descr.address = fix_to_virt(FIX_F00F_IDT);
 	load_idt(&idt_descr);
+	immediate_set_early(&f00f_bug_fix, 1);
 }
 #endif
 
Index: linux-2.6-lttng/arch/i386/mm/fault.c
===================================================================
--- linux-2.6-lttng.orig/arch/i386/mm/fault.c	2007-07-13 19:25:38.000000000 -0400
+++ linux-2.6-lttng/arch/i386/mm/fault.c	2007-07-13 19:30:55.000000000 -0400
@@ -25,6 +25,7 @@
 #include <linux/kprobes.h>
 #include <linux/uaccess.h>
 #include <linux/kdebug.h>
+#include <linux/immediate.h>
 
 #include <asm/system.h>
 #include <asm/desc.h>
@@ -492,7 +493,7 @@
 	/*
 	 * Pentium F0 0F C7 C8 bug workaround.
 	 */
-	if (boot_cpu_data.f00f_bug) {
+	immediate_if (&f00f_bug_fix) {
 		unsigned long nr;
 		
 		nr = (address - idt_descr.address) >> 3;
Index: linux-2.6-lttng/include/asm-i386/processor.h
===================================================================
--- linux-2.6-lttng.orig/include/asm-i386/processor.h	2007-07-13 19:25:38.000000000 -0400
+++ linux-2.6-lttng/include/asm-i386/processor.h	2007-07-13 19:30:55.000000000 -0400
@@ -21,6 +21,7 @@
 #include <asm/percpu.h>
 #include <linux/cpumask.h>
 #include <linux/init.h>
+#include <linux/immediate.h>
 #include <asm/processor-flags.h>
 
 /* flag for disabling the tsc */
@@ -102,6 +103,8 @@
 extern struct tss_struct doublefault_tss;
 DECLARE_PER_CPU(struct tss_struct, init_tss);
 
+extern immediate_char_t f00f_bug_fix;
+
 #ifdef CONFIG_SMP
 extern struct cpuinfo_x86 cpu_data[];
 #define current_cpu_data cpu_data[smp_processor_id()]

-- 
Mathieu Desnoyers
Computer Engineering Ph.D. Student, Ecole Polytechnique de Montreal
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F  BA06 3F25 A8FE 3BAE 9A68
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