From f33f79d09a1e7c214a206b3ee5c2d29b95f8f3b3 Mon Sep 17 00:00:00 2001 From: "Aneesh Kumar K.V" Date: Fri, 18 Aug 2017 17:37:00 +0200 Subject: [PATCH] powerpc/mm/radix: Optimise tlbiel flush all case BugLink: http://bugs.launchpad.net/bugs/1709220 _tlbiel_pid() is called with a ric (Radix Invalidation Control) argument of either RIC_FLUSH_TLB or RIC_FLUSH_ALL. RIC_FLUSH_ALL says to invalidate the entire TLB and the Page Walk Cache (PWC). To flush the whole TLB, we have to iterate over each set (congruence class) of the TLB. Currently we do that and pass RIC_FLUSH_ALL each time. That is not incorrect but it means we flush the PWC 128 times, when once would suffice. Fix it by doing the first flush with the ric value we're passed, and then if it was RIC_FLUSH_ALL, we downgrade it to RIC_FLUSH_TLB, because we know we have just flushed the PWC and don't need to do it again. Signed-off-by: Aneesh Kumar K.V [mpe: Split out of combined patch, tweak logic, rewrite change log] Signed-off-by: Michael Ellerman (cherry picked from commit a5998fcb92552a18713b6aa5c146aa400e4d75ee) Signed-off-by: Joseph Salisbury Acked-by: Stefan Bader Acked-by: Seth Forshee Signed-off-by: Kleber Sacilotto de Souza --- arch/powerpc/mm/tlb-radix.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/mm/tlb-radix.c b/arch/powerpc/mm/tlb-radix.c index 93c9d8080b2a..5e531e46ca3a 100644 --- a/arch/powerpc/mm/tlb-radix.c +++ b/arch/powerpc/mm/tlb-radix.c @@ -46,9 +46,20 @@ static inline void _tlbiel_pid(unsigned long pid, unsigned long ric) int set; asm volatile("ptesync": : :"memory"); - for (set = 0; set < POWER9_TLB_SETS_RADIX ; set++) { + + /* + * Flush the first set of the TLB, and if we're doing a RIC_FLUSH_ALL, + * also flush the entire Page Walk Cache. + */ + __tlbiel_pid(pid, 0, ric); + + if (ric == RIC_FLUSH_ALL) + /* For the remaining sets, just flush the TLB */ + ric = RIC_FLUSH_TLB; + + for (set = 1; set < POWER9_TLB_SETS_RADIX ; set++) __tlbiel_pid(pid, set, ric); - } + asm volatile("ptesync": : :"memory"); asm volatile(PPC_INVALIDATE_ERAT "; isync" : : :"memory"); } -- 2.39.2