[PATCH 4.9 084/222] powerpc/64s/hash: Fix stab_rr off by one initialization

[Greg Kroah-Hartman]

From: Nicholas Piggin <npiggin@xxxxxxxxx>

[ Upstream commit 09b4438db13fa83b6219aee5993711a2aa2a0c64 ]

This causes SLB alloation to start 1 beyond the start of the SLB.
There is no real problem because after it wraps it stats behaving
properly, it's just surprisig to see when looking at SLB traces.

Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/powerpc/mm/slb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index 64c9a91773af4..96c41b55b106b 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -321,7 +321,7 @@ void slb_initialize(void)
 #endif
 	}
 
-	get_paca()->stab_rr = SLB_NUM_BOLTED;
+	get_paca()->stab_rr = SLB_NUM_BOLTED - 1;
 
 	lflags = SLB_VSID_KERNEL | linear_llp;
 	vflags = SLB_VSID_KERNEL | vmalloc_llp;
-- 
2.20.1