[POWERPC] 40x/Book-E: Save/restore volatile exception registers

On machines with more than one exception level any system register that
might be modified by the "normal" exception level needs to be saved and
restored on taking a higher level exception.  We already are saving
and restoring ESR and DEAR.

For critical level add SRR0/1.
For debug level add CSRR0/1 and SRR0/1.
For machine check level add DSRR0/1, CSRR0/1, and SRR0/1.

On FSL Book-E parts we always save/restore the MAS registers for critical,
debug, and machine check level exceptions.  On 44x we always save/restore
the MMUCR.

Additionally, we save and restore the ksp_limit since we have to adjust it
for each exception level.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Acked-by: Paul Mackerras <paulus@samba.org>

1 files changed, 23 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index ec9228d687b0..8655c7670350 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -52,6 +52,10 @@
 #include <asm/iseries/alpaca.h>
 #endif
 
+#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+#include "head_booke.h"
+#endif
+
 int main(void)
 {
         DEFINE(THREAD, offsetof(struct task_struct, thread));
@@ -242,6 +246,25 @@ int main(void)
         DEFINE(_SRR1, STACK_FRAME_OVERHEAD+sizeof(struct pt_regs)+8);
 #endif /* CONFIG_PPC64 */
 
+#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
+        DEFINE(EXC_LVL_SIZE, STACK_EXC_LVL_FRAME_SIZE);
+        DEFINE(MAS0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas0));
+        /* we overload MMUCR for 44x on MAS0 since they are mutually exclusive */
+        DEFINE(MMUCR, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas0));
+        DEFINE(MAS1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas1));
+        DEFINE(MAS2, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas2));
+        DEFINE(MAS3, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas3));
+        DEFINE(MAS6, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas6));
+        DEFINE(MAS7, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, mas7));
+        DEFINE(_SRR0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, srr0));
+        DEFINE(_SRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, srr1));
+        DEFINE(_CSRR0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, csrr0));
+        DEFINE(_CSRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, csrr1));
+        DEFINE(_DSRR0, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, dsrr0));
+        DEFINE(_DSRR1, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, dsrr1));
+        DEFINE(SAVED_KSP_LIMIT, STACK_INT_FRAME_SIZE+offsetof(struct exception_regs, saved_ksp_limit));
+#endif
+
         DEFINE(CLONE_VM, CLONE_VM);
         DEFINE(CLONE_UNTRACED, CLONE_UNTRACED);