microblaze: Remove r0_ram pointer and PTO alignment
r0_ram pool was used for saving/restoring register
content if hw exception happen. This poll was replaced by
pt_pool_space with PT_SIZE size.
Based on this change SAVE_STATE_ARG_SPACE was removed which
caused that PTO offset is zero that's why is also removed.
r0_ram space was used as scratchpad by v850. In early
Microblaze Linux developing phase was this part of code
blindly copied.
Signed-off-by: Michal Simek <monstr@monstr.eu>
diff --git a/arch/microblaze/kernel/hw_exception_handler.S b/arch/microblaze/kernel/hw_exception_handler.S
index ec5e99d..2401fa4b 100644
--- a/arch/microblaze/kernel/hw_exception_handler.S
+++ b/arch/microblaze/kernel/hw_exception_handler.S
@@ -93,7 +93,7 @@
lwi r6, r1, PT_R6; \
lwi r11, r1, PT_R11; \
lwi r31, r1, PT_R31; \
- lwi r1, r0, TOPHYS(r0_ram + 0);
+ lwi r1, r1, PT_R1;
#endif /* CONFIG_MMU */
#define LWREG_NOP \
@@ -208,8 +208,8 @@
* | . |
* | . |
*
- * NO_MMU kernel use the same r0_ram pointed space - look to vmlinux.lds.S
- * which is used for storing register values - old style was, that value were
+ * MMU kernel uses the same 'pt_pool_space' pointed space
+ * which is used for storing register values - noMMu style was, that values were
* stored in stack but in case of failure you lost information about register.
* Currently you can see register value in memory in specific place.
* In compare to with previous solution the speed should be the same.
@@ -228,8 +228,12 @@
*/
/* wrappers to restore state before coming to entry.S */
-
#ifdef CONFIG_MMU
+.section .data
+.align 4
+pt_pool_space:
+ .space PT_SIZE
+
#ifdef DEBUG
/* Create space for exception counting. */
.section .data
@@ -299,10 +303,10 @@
#ifndef CONFIG_MMU
addik r1, r1, -(EX_HANDLER_STACK_SIZ); /* Create stack frame */
#else
- swi r1, r0, TOPHYS(r0_ram + 0); /* GET_SP */
+ swi r1, r0, TOPHYS(pt_pool_space + PT_R1); /* GET_SP */
/* Save date to kernel memory. Here is the problem
* when you came from user space */
- ori r1, r0, TOPHYS(r0_ram + 28);
+ ori r1, r0, TOPHYS(pt_pool_space);
#endif
swi r3, r1, PT_R3
swi r4, r1, PT_R4
