From 0f52b3a00c789569d7ed822b5a6b30f59a8d4393 Mon Sep 17 00:00:00 2001 From: Mahesh Salgaonkar Date: Thu, 23 Aug 2018 10:26:08 +0530 Subject: [PATCH] powerpc/mce: Fix SLB rebolting during MCE recovery path. The commit e7e81847478 ("powerpc/64s: move machine check SLB flushing to mm/slb.c") introduced a bug in reloading bolted SLB entries. Unused bolted entries are stored with .esid=0 in the slb_shadow area, and that value is now used directly as the RB input to slbmte, which means the RB[52:63] index field is set to 0, which causes SLB entry 0 to be cleared. Fix this by storing the index bits in the unused bolted entries, which directs the slbmte to the right place. The SLB shadow area is also used by the hypervisor, but PAPR is okay with that, from LoPAPR v1.1, 14.11.1.3 SLB Shadow Buffer: Note: SLB is filled sequentially starting at index 0 from the shadow buffer ignoring the contents of RB field bits 52-63 Fixes: e7e81847478b ("powerpc/64s: move machine check SLB flushing to mm/slb.c") Signed-off-by: Mahesh Salgaonkar Signed-off-by: Nicholas Piggin Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman --- 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 0b095fa54049..9f574e59d178 100644 --- a/arch/powerpc/mm/slb.c +++ b/arch/powerpc/mm/slb.c @@ -70,7 +70,7 @@ static inline void slb_shadow_update(unsigned long ea, int ssize, static inline void slb_shadow_clear(enum slb_index index) { - WRITE_ONCE(get_slb_shadow()->save_area[index].esid, 0); + WRITE_ONCE(get_slb_shadow()->save_area[index].esid, cpu_to_be64(index)); } static inline void create_shadowed_slbe(unsigned long ea, int ssize, -- 2.30.2