powerpc/tm: Save MSR to PACA before RFID

As other exit points, move SRR1 (MSR) into paca->tm_scratch, so, if
there is a TM Bad Thing in RFID, it is easy to understand what was the
SRR1 value being used.

Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 7c2032e..5fe1431 100644 (file)
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -291,6 +291,10 @@ BEGIN_FTR_SECTION
        HMT_MEDIUM_LOW
 END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
 
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+       std     r8, PACATMSCRATCH(r13)
+#endif
+
        ld      r13,GPR13(r1)   /* only restore r13 if returning to usermode */
        ld      r2,GPR2(r1)
        ld      r1,GPR1(r1)