[PATCH] ppc32: Add support for Freescale e200 (Book-E) core
The e200 core is a Book-E core (similar to e500) that has a unified L1 cache
and is not cache coherent on the bus. The e200 core also adds a separate
exception level for debug exceptions. Part of this patch helps to cleanup a
few cases that are true for all Freescale Book-E parts, not just e500.
Signed-off-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Kumar Gala <kumar.gala@freescale.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/arch/ppc/kernel/head_booke.h b/arch/ppc/kernel/head_booke.h
index 9c50f9d..9342acf 100644
--- a/arch/ppc/kernel/head_booke.h
+++ b/arch/ppc/kernel/head_booke.h
@@ -49,6 +49,7 @@
*
* On 40x critical is the only additional level
* On 44x/e500 we have critical and machine check
+ * On e200 we have critical and debug (machine check occurs via critical)
*
* Additionally we reserve a SPRG for each priority level so we can free up a
* GPR to use as the base for indirect access to the exception stacks. This
@@ -60,12 +61,16 @@
/* CRIT_SPRG only used in critical exception handling */
#define CRIT_SPRG SPRN_SPRG2
-/* MCHECK_SPRG only used in critical exception handling */
+/* 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)
+/* only on e200 for now */
+#define DEBUG_STACK_TOP (exception_stack_top - 4096)
+#define DEBUG_SPRG SPRN_SPRG6W
+
#ifdef CONFIG_SMP
#define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
mfspr r8,SPRN_PIR; \
@@ -124,6 +129,8 @@
#define CRITICAL_EXCEPTION_PROLOG \
EXC_LEVEL_EXCEPTION_PROLOG(CRIT, SPRN_CSRR0, SPRN_CSRR1)
+#define DEBUG_EXCEPTION_PROLOG \
+ EXC_LEVEL_EXCEPTION_PROLOG(DEBUG, SPRN_DSRR0, SPRN_DSRR1)
#define MCHECK_EXCEPTION_PROLOG \
EXC_LEVEL_EXCEPTION_PROLOG(MCHECK, SPRN_MCSRR0, SPRN_MCSRR1)
@@ -205,6 +212,60 @@
* save (and later restore) the MSR via SPRN_CSRR1, which will still have
* the MSR_DE bit set.
*/
+#ifdef CONFIG_E200
+#define DEBUG_EXCEPTION \
+ START_EXCEPTION(Debug); \
+ DEBUG_EXCEPTION_PROLOG; \
+ \
+ /* \
+ * If there is a single step or branch-taken exception in an \
+ * exception entry sequence, it was probably meant to apply to \
+ * the code where the exception occurred (since exception entry \
+ * doesn't turn off DE automatically). We simulate the effect \
+ * of turning off DE on entry to an exception handler by turning \
+ * off DE in the CSRR1 value and clearing the debug status. \
+ */ \
+ mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
+ andis. r10,r10,DBSR_IC@h; \
+ beq+ 2f; \
+ \
+ lis r10,KERNELBASE@h; /* check if exception in vectors */ \
+ ori r10,r10,KERNELBASE@l; \
+ cmplw r12,r10; \
+ blt+ 2f; /* addr below exception vectors */ \
+ \
+ lis r10,Debug@h; \
+ ori r10,r10,Debug@l; \
+ cmplw r12,r10; \
+ bgt+ 2f; /* addr above exception vectors */ \
+ \
+ /* here it looks like we got an inappropriate debug exception. */ \
+1: rlwinm r9,r9,0,~MSR_DE; /* clear DE in the CDRR1 value */ \
+ lis r10,DBSR_IC@h; /* clear the IC event */ \
+ mtspr SPRN_DBSR,r10; \
+ /* restore state and get out */ \
+ lwz r10,_CCR(r11); \
+ lwz r0,GPR0(r11); \
+ lwz r1,GPR1(r11); \
+ mtcrf 0x80,r10; \
+ mtspr SPRN_DSRR0,r12; \
+ mtspr SPRN_DSRR1,r9; \
+ lwz r9,GPR9(r11); \
+ lwz r12,GPR12(r11); \
+ mtspr DEBUG_SPRG,r8; \
+ BOOKE_LOAD_EXC_LEVEL_STACK(DEBUG); /* r8 points to the debug stack */ \
+ lwz r10,GPR10-INT_FRAME_SIZE(r8); \
+ lwz r11,GPR11-INT_FRAME_SIZE(r8); \
+ mfspr r8,DEBUG_SPRG; \
+ \
+ RFDI; \
+ b .; \
+ \
+ /* continue normal handling for a critical exception... */ \
+2: mfspr r4,SPRN_DBSR; \
+ addi r3,r1,STACK_FRAME_OVERHEAD; \
+ EXC_XFER_TEMPLATE(DebugException, 0x2002, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), NOCOPY, debug_transfer_to_handler, ret_from_debug_exc)
+#else
#define DEBUG_EXCEPTION \
START_EXCEPTION(Debug); \
CRITICAL_EXCEPTION_PROLOG; \
@@ -257,6 +318,7 @@
2: mfspr r4,SPRN_DBSR; \
addi r3,r1,STACK_FRAME_OVERHEAD; \
EXC_XFER_TEMPLATE(DebugException, 0x2002, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), NOCOPY, crit_transfer_to_handler, ret_from_crit_exc)
+#endif
#define INSTRUCTION_STORAGE_EXCEPTION \
START_EXCEPTION(InstructionStorage) \