ARM: 8078/1: get rid of hardcoded assumptions about kernel stack size
Changing kernel stack size on arm is not as simple as it should be:
1) THREAD_SIZE macro doesn't respect PAGE_SIZE and THREAD_SIZE_ORDER
2) stack size is hardcoded in get_thread_info macro
This patch fixes it by calculating THREAD_SIZE and thread_info address
taking into account PAGE_SIZE and THREAD_SIZE_ORDER.
Now changing stack size becomes simply changing THREAD_SIZE_ORDER.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 57f0584..906703a 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -24,6 +24,8 @@
#include <asm/domain.h>
#include <asm/opcodes-virt.h>
#include <asm/asm-offsets.h>
+#include <asm/page.h>
+#include <asm/thread_info.h>
#define IOMEM(x) (x)
@@ -179,10 +181,10 @@
* Get current thread_info.
*/
.macro get_thread_info, rd
- ARM( mov \rd, sp, lsr #13 )
+ ARM( mov \rd, sp, lsr #THREAD_SIZE_ORDER + PAGE_SHIFT )
THUMB( mov \rd, sp )
- THUMB( lsr \rd, \rd, #13 )
- mov \rd, \rd, lsl #13
+ THUMB( lsr \rd, \rd, #THREAD_SIZE_ORDER + PAGE_SHIFT )
+ mov \rd, \rd, lsl #THREAD_SIZE_ORDER + PAGE_SHIFT
.endm
/*
diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h
index e4e4208..fc44d37 100644
--- a/arch/arm/include/asm/thread_info.h
+++ b/arch/arm/include/asm/thread_info.h
@@ -14,9 +14,10 @@
#include <linux/compiler.h>
#include <asm/fpstate.h>
+#include <asm/page.h>
#define THREAD_SIZE_ORDER 1
-#define THREAD_SIZE 8192
+#define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER)
#define THREAD_START_SP (THREAD_SIZE - 8)
#ifndef __ASSEMBLY__