From: Nicholas Piggin <npiggin@gmail.com>
Date: Fri, 14 Sep 2018 15:30:45 +0000 (+1000)
Subject: powerpc/64s/hash: Fix stab_rr off by one initialization
X-Git-Tag: v4.20-rc1~97^2~202
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=09b4438db13fa83b6219aee5993711a2aa2a0c64;p=thirdparty%2Fkernel%2Flinux.git

powerpc/64s/hash: Fix stab_rr off by one initialization

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@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---

diff --git a/arch/powerpc/mm/slb.c b/arch/powerpc/mm/slb.c
index e941189d9bd63..07ece013856b5 100644
--- a/arch/powerpc/mm/slb.c
+++ b/arch/powerpc/mm/slb.c
@@ -425,7 +425,7 @@ 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;