[XTENSA] Add missing a2 register restore in register spill routine

Register a2 is saved in depc but wasn't getting restored before
returning from _spill_registers when there weren't any registers
to spill. The mask to cut the top bit from the rotated WINDOWMASK
register was also one bit short.

Signed-off-by: CHris Zankel <chris@zankel.net>

1 files changed, 5 insertions, 3 deletions

diff --git a/arch/xtensa/kernel/entry.S b/arch/xtensa/kernel/entry.S
index 91a689eca43d..401b33bfd9c0 100644
--- a/arch/xtensa/kernel/entry.S
+++ b/arch/xtensa/kernel/entry.S
@@ -1344,7 +1344,7 @@ ENTRY(_spill_registers)
 
         /* We are done if there are no more than the current register frame. */
 
-        extui   a3, a3, 1, WSBITS-2     # a3 = 0yyxxxwww
+        extui   a3, a3, 1, WSBITS-1     # a3 = 0yyxxxwww
         movi    a2, (1 << (WSBITS-1))
         _beqz   a3, .Lnospill           # only one active frame? jump
 
@@ -1394,6 +1394,10 @@ ENTRY(_spill_registers)
         l32e    a4, a1, -16
         j       .Lc12c
 
+.Lnospill:
+        rsr     a2, DEPC        # restore a2 and 'return'
+        jx      a0
+
 .Lloop: _bbsi.l a3, 1, .Lc4
         _bbci.l a3, 2, .Lc12
 
@@ -1419,8 +1423,6 @@ ENTRY(_spill_registers)
         movi    a3, 1
         sll     a3, a3
         wsr     a3, WINDOWSTART
-
-.Lnospill:
         jx      a0
 
 .Lc4:   s32e    a4, a9, -16