[PATCH REPOST] [1/3] Don't set up early exception handlers for external interrupts

From: Andi Kleen
Date: Tue Mar 04 2008 - 16:14:07 EST



All of early setup runs with interrupts disabled, so there is no
need to set up early exception handlers for vectors >= 32

That saves some text size

Signed-off-by: Andi Kleen <ak@xxxxxxx>

---
arch/x86/kernel/head64.c | 2 +-
arch/x86/kernel/head_64.S | 6 ++----
include/asm-x86/segment.h | 3 ++-
3 files changed, 5 insertions(+), 6 deletions(-)

Index: linux/arch/x86/kernel/head64.c
===================================================================
--- linux.orig/arch/x86/kernel/head64.c
+++ linux/arch/x86/kernel/head64.c
@@ -91,7 +91,7 @@ void __init x86_64_start_kernel(char * r
/* Cleanup the over mapped high alias */
cleanup_highmap();

- for (i = 0; i < IDT_ENTRIES; i++) {
+ for (i = 0; i < NUM_EXCEPTION_VECTORS; i++) {
#ifdef CONFIG_EARLY_PRINTK
set_intr_gate(i, &early_idt_handlers[i]);
#else
Index: linux/include/asm-x86/segment.h
===================================================================
--- linux.orig/include/asm-x86/segment.h
+++ linux/include/asm-x86/segment.h
@@ -191,13 +191,14 @@
#define SEGMENT_TI_MASK 0x4

#define IDT_ENTRIES 256
+#define NUM_EXCEPTION_VECTORS 32
#define GDT_SIZE (GDT_ENTRIES * 8)
#define GDT_ENTRY_TLS_ENTRIES 3
#define TLS_SIZE (GDT_ENTRY_TLS_ENTRIES * 8)

#ifdef __KERNEL__
#ifndef __ASSEMBLY__
-extern const char early_idt_handlers[IDT_ENTRIES][10];
+extern const char early_idt_handlers[NUM_EXCEPTION_VECTORS][10];
#endif
#endif

Index: linux/arch/x86/kernel/head_64.S
===================================================================
--- linux.orig/arch/x86/kernel/head_64.S
+++ linux/arch/x86/kernel/head_64.S
@@ -278,10 +278,8 @@ bad_address:

.globl early_idt_handlers
early_idt_handlers:
- early_idt_tramp 0, 63
- early_idt_tramp 64, 127
- early_idt_tramp 128, 191
- early_idt_tramp 192, 255
+ .set maxe,NUM_EXCEPTION_VECTORS-1
+ early_idt_tramp 0,maxe
#endif

ENTRY(early_idt_handler)
--
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