[POWERPC] Move to runtime allocated exception stacks
For the additonal exception levels (critical, debug, machine check) on
40x/book-e we were using "static" allocations of the stack in the
associated head.S.
Move to a runtime allocation to make the code a bit easier to read as
we mimic how we handle IRQ stacks. Its also a bit easier to setup the
stack with a "dummy" thread_info in C code.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h
index 721faef..9eacf4c 100644
--- a/arch/powerpc/kernel/head_booke.h
+++ b/arch/powerpc/kernel/head_booke.h
@@ -43,9 +43,7 @@
SAVE_2GPRS(7, r11)
/* To handle the additional exception priority levels on 40x and Book-E
- * processors we allocate a 4k stack per additional priority level. The various
- * head_xxx.S files allocate space (exception_stack_top) for each priority's
- * stack times the number of CPUs
+ * processors we allocate a stack per additional priority level.
*
* On 40x critical is the only additional level
* On 44x/e500 we have critical and machine check
@@ -61,36 +59,31 @@
* going to critical or their own debug level we aren't currently
* providing configurations that micro-optimize space usage.
*/
-#ifdef CONFIG_44x
-#define NUM_EXCEPTION_LVLS 2
-#else
-#define NUM_EXCEPTION_LVLS 3
-#endif
-#define BOOKE_EXCEPTION_STACK_SIZE (4096 * NUM_EXCEPTION_LVLS)
/* CRIT_SPRG only used in critical exception handling */
#define CRIT_SPRG SPRN_SPRG2
/* MCHECK_SPRG only used in machine check exception handling */
#define MCHECK_SPRG SPRN_SPRG6W
-#define MCHECK_STACK_TOP (exception_stack_top - 4096)
-#define CRIT_STACK_TOP (exception_stack_top)
+#define MCHECK_STACK_BASE mcheckirq_ctx
+#define CRIT_STACK_BASE critirq_ctx
/* only on e200 for now */
-#define DEBUG_STACK_TOP (exception_stack_top - 8192)
+#define DEBUG_STACK_BASE dbgirq_ctx
#define DEBUG_SPRG SPRN_SPRG6W
#ifdef CONFIG_SMP
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
mfspr r8,SPRN_PIR; \
- mulli r8,r8,BOOKE_EXCEPTION_STACK_SIZE; \
- neg r8,r8; \
- addis r8,r8,level##_STACK_TOP@ha; \
- addi r8,r8,level##_STACK_TOP@l
+ slwi r8,r8,2; \
+ addis r8,r8,level##_STACK_BASE@ha; \
+ lwz r8,level##_STACK_BASE@l(r8); \
+ addi r8,r8,THREAD_SIZE;
#else
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
- lis r8,level##_STACK_TOP@h; \
- ori r8,r8,level##_STACK_TOP@l
+ lis r8,level##_STACK_BASE@ha; \
+ lwz r8,level##_STACK_BASE@l(r8); \
+ addi r8,r8,THREAD_SIZE;
#endif
/*