sparc64: Do not clobber %g2 in xcall_fetch_glob_regs().

BugLink: http://bugs.launchpad.net/bugs/1002880

[ Upstream commit a5a737e090e25981e99d69f01400e3a80356581c ]

%g2 is meant to hold the CPUID number throughout this routine, since
at the very beginning, and at the very end, we use %g2 to calculate
indexes into per-cpu arrays.

However we erroneously clobber it in order to hold the %cwp register
value mid-stream.

Fix this code to use %g3 for the %cwp read and related calulcations
instead.

Reported-by: Meelis Roos <mroos@linux.ee>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

2 files changed, 4 insertions, 4 deletions

diff --git a/arch/sparc/kernel/central.c b/arch/sparc/kernel/central.c
index 7eef3f74196..f5ddc0bae38 100644
--- a/arch/sparc/kernel/central.c
+++ b/arch/sparc/kernel/central.c
@@ -268,4 +268,4 @@ static int __init sunfire_init(void)
         return 0;
 }
 
-subsys_initcall(sunfire_init);
+fs_initcall(sunfire_init);
diff --git a/arch/sparc/mm/ultra.S b/arch/sparc/mm/ultra.S
index b57a5942ba6..874162a11ce 100644
--- a/arch/sparc/mm/ultra.S
+++ b/arch/sparc/mm/ultra.S
@@ -495,11 +495,11 @@ xcall_fetch_glob_regs:
         stx             %o7, [%g1 + GR_SNAP_O7]
         stx             %i7, [%g1 + GR_SNAP_I7]
         /* Don't try this at home kids... */
-        rdpr            %cwp, %g2
-        sub             %g2, 1, %g7
+        rdpr            %cwp, %g3
+        sub             %g3, 1, %g7
         wrpr            %g7, %cwp
         mov             %i7, %g7
-        wrpr            %g2, %cwp
+        wrpr            %g3, %cwp
         stx             %g7, [%g1 + GR_SNAP_RPC]
         sethi           %hi(trap_block), %g7
         or              %g7, %lo(trap_block), %g7