ppc64: make sure to align stack pointer to 16 bytes at boot

yaboot is scrogged and calls us with an invalid stack alignment,
it seems.

Thanks to David Woodhouse to pointing me to the problem.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 11f2cd5af7dc..9b65029dd2a3 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -1537,6 +1537,9 @@ _STATIC(__boot_from_prom)
         mr      r28,r6
         mr      r27,r7
 
+        /* Align the stack to 16-byte boundary for broken yaboot */
+        rldicr  r1,r1,0,59
+
         /* Make sure we are running in 64 bits mode */
         bl      .enable_64b_mode