From ebb9d30a6a74f4ced5b7d35446ebb6362a724393 Mon Sep 17 00:00:00 2001 From: chenhui zhao Date: Thu, 24 Dec 2015 08:39:57 +0800 Subject: [PATCH] powerpc/mm: any thread in one core can be the first to setup TLB1 On e6500, in the case of cpu hotplug, either thread in one core may be the first thread initilzing the TLB1. The subsequent threads must not setup it again. The code is derived from the comment of Scott Wood. Signed-off-by: Chenhui Zhao Signed-off-by: Scott Wood --- arch/powerpc/include/asm/cputhreads.h | 8 ++++++++ arch/powerpc/mm/tlb_nohash.c | 4 +--- 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/arch/powerpc/include/asm/cputhreads.h b/arch/powerpc/include/asm/cputhreads.h index ba42e46ea58e..ea9623147b87 100644 --- a/arch/powerpc/include/asm/cputhreads.h +++ b/arch/powerpc/include/asm/cputhreads.h @@ -94,6 +94,14 @@ static inline int cpu_last_thread_sibling(int cpu) return cpu | (threads_per_core - 1); } +static inline u32 get_tensr(void) +{ +#ifdef CONFIG_BOOKE + if (cpu_has_feature(CPU_FTR_SMT)) + return mfspr(SPRN_TENSR); +#endif + return 1; +} #endif /* _ASM_POWERPC_CPUTHREADS_H */ diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c index bb04e4df3100..f4668488512c 100644 --- a/arch/powerpc/mm/tlb_nohash.c +++ b/arch/powerpc/mm/tlb_nohash.c @@ -640,9 +640,7 @@ static void early_init_this_mmu(void) * transient mapping would cause problems. */ #ifdef CONFIG_SMP - if (cpu != boot_cpuid && - (cpu != cpu_first_thread_sibling(cpu) || - cpu == cpu_first_thread_sibling(boot_cpuid))) + if (hweight32(get_tensr()) > 1) map = false; #endif -- 2.34.1