[PATCH 1/2] i386: double fault adjustment - introduce THREAD_ORDER

["Jan Beulich" <JBeulich@novell.com>]

[-- Attachment #1: Type: text/plain, Size: 328 bytes --]

This introduces THREAD_ORDER (to accompany THREAD_SIZE, which now
becomes a derivate of the former) in order to easily pass this to page
allocation routines. Code consuming this (fixing the double fault
handler to use per-CPU stacks) will soon follow.

Signed-Off-By: Jan Beulich <jbeulich@novell.com>

(actual patch attached)


[-- Attachment #2: linux-2.6.14-i386-THREAD_ORDER.patch --]
[-- Type: application/octet-stream, Size: 3183 bytes --]

This introduces THREAD_ORDER (to accompany THREAD_SIZE, which now
becomes a derivate of the former) in order to easily pass this to page
allocation routines. Code consuming this (fixing the double fault
handler to use per-CPU stacks) will soon follow.

Signed-Off-By: Jan Beulich <jbeulich@novell.com>

--- 2.6.14/arch/i386/kernel/asm-offsets.c	2005-10-28 02:02:08.000000000 +0200
+++ 2.6.14-i386-THREAD_ORDER/arch/i386/kernel/asm-offsets.c	2005-11-04 16:19:32.000000000 +0100
@@ -68,5 +68,6 @@ void foo(void)
 		 sizeof(struct tss_struct));
 
 	DEFINE(PAGE_SIZE_asm, PAGE_SIZE);
+	DEFINE(THREAD_SIZE_asm, THREAD_SIZE);
 	DEFINE(VSYSCALL_BASE, __fix_to_virt(FIX_VSYSCALL));
 }
--- 2.6.14/arch/i386/kernel/entry.S	2005-10-28 02:02:08.000000000 +0200
+++ 2.6.14-i386-THREAD_ORDER/arch/i386/kernel/entry.S	2005-11-04 16:45:13.000000000 +0100
@@ -540,8 +540,8 @@ ENTRY(nmi)
 	/* Do not access memory above the end of our stack page,
 	 * it might not exist.
 	 */
-	andl $(THREAD_SIZE-1),%eax
-	cmpl $(THREAD_SIZE-20),%eax
+	andl $(THREAD_SIZE_asm-1),%eax
+	cmpl $(THREAD_SIZE_asm-20),%eax
 	popl %eax
 	jae nmi_stack_correct
 	cmpl $sysenter_entry,12(%esp)
--- 2.6.14/arch/i386/kernel/head.S	2005-10-28 02:02:08.000000000 +0200
+++ 2.6.14-i386-THREAD_ORDER/arch/i386/kernel/head.S	2005-11-04 16:47:02.000000000 +0100
@@ -429,7 +429,7 @@ ENTRY(empty_zero_page)
 .data
 
 ENTRY(stack_start)
-	.long init_thread_union+THREAD_SIZE
+	.long init_thread_union+THREAD_SIZE_asm
 	.long __BOOT_DS
 
 ready:	.byte 0
--- 2.6.14/arch/i386/kernel/vmlinux.lds.S	2005-10-28 02:02:08.000000000 +0200
+++ 2.6.14-i386-THREAD_ORDER/arch/i386/kernel/vmlinux.lds.S	2005-11-08 14:45:53.000000000 +0100
@@ -4,8 +4,9 @@
 
 #define LOAD_OFFSET __PAGE_OFFSET
 
+#include <linux/config.h>
 #include <asm-generic/vmlinux.lds.h>
-#include <asm/thread_info.h>
+#include <asm/asm-offsets.h>
 #include <asm/page.h>
 
 OUTPUT_FORMAT("elf32-i386", "elf32-i386", "elf32-i386")
@@ -63,7 +64,7 @@ SECTIONS
   .data.read_mostly : AT(ADDR(.data.read_mostly) - LOAD_OFFSET) { *(.data.read_mostly) }
   _edata = .;			/* End of data section */
 
-  . = ALIGN(THREAD_SIZE);	/* init_task */
+  . = ALIGN(THREAD_SIZE_asm);	/* init_task */
   .data.init_task : AT(ADDR(.data.init_task) - LOAD_OFFSET) {
 	*(.data.init_task)
   }
--- 2.6.14/include/asm-i386/thread_info.h	2005-10-28 02:02:08.000000000 +0200
+++ 2.6.14-i386-THREAD_ORDER/include/asm-i386/thread_info.h	2005-11-04 16:19:34.000000000 +0100
@@ -54,10 +54,11 @@ struct thread_info {
 
 #define PREEMPT_ACTIVE		0x10000000
 #ifdef CONFIG_4KSTACKS
-#define THREAD_SIZE            (4096)
+#define THREAD_ORDER 0
 #else
-#define THREAD_SIZE		(8192)
+#define THREAD_ORDER 1
 #endif
+#define THREAD_SIZE (PAGE_SIZE << THREAD_ORDER)
 
 #define STACK_WARN             (THREAD_SIZE/8)
 /*
@@ -118,12 +119,12 @@ register unsigned long current_stack_poi
 
 /* how to get the thread information struct from ASM */
 #define GET_THREAD_INFO(reg) \
-	movl $-THREAD_SIZE, reg; \
+	movl $-THREAD_SIZE_asm, reg; \
 	andl %esp, reg
 
 /* use this one if reg already contains %esp */
 #define GET_THREAD_INFO_WITH_ESP(reg) \
-	andl $-THREAD_SIZE, reg
+	andl $-THREAD_SIZE_asm, reg
 
 #endif