[PATCH 1/2] powerpc/kexec: Reset secondary cpu endianess before kexec

[Samuel Mendoza-Jonas <sam.mj@au1.ibm.com>]

If the target kernel does not inlcude the FIXUP_ENDIAN check, coming
from a different-endian kernel will cause the target kernel to panic.
All ppc64 kernels can handle starting in big-endian mode, so return to
big-endian before branching into the target kernel.

This mainly affects pseries as secondaries on powernv are returned to
OPAL.

Signed-off-by: Samuel Mendoza-Jonas <sam.mj@au1.ibm.com>
---
 arch/powerpc/kernel/misc_64.S | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 4e314b9..c73e587 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -475,9 +475,20 @@ _GLOBAL(kexec_wait)
 #ifdef CONFIG_KEXEC		/* use no memory without kexec */
 	lwz	r4,0(r5)
 	cmpwi	0,r4,0
-	bnea	0x60
+	beq	99b
+	mfmsr	r9		/* Check endianess */
+	clrldi.	r10,r9,63
+	beqa	0x60		/* Already big-endian */
+	bcl	20,31,$+4
+	mflr	r10
+	addi	r10,r10,28
+	mfmsr	r11
+	xori	r11,r11,1
+	mtsrr0	r10
+	mtsrr1	r11
+	rfid
+	.long	0x62000048	/* ba 0x60 */
 #endif
-	b	99b
 
 /* this can be in text because we won't change it until we are
  * running in real anyways
-- 
2.4.5