From 3a2df3798d4da2fc40052c25f0d9c687b1467d53 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Mon, 24 Jul 2017 14:28:03 +1000 Subject: [PATCH] powerpc/mm: Make switch_mm_irqs_off() out of line It's too big to be inline, there is no reason to keep it that way. Signed-off-by: Benjamin Herrenschmidt [mpe: Rework to incorporate the comment changes via fixes branch] Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/mmu_context.h | 89 +----------------------------- arch/powerpc/mm/Makefile | 2 +- arch/powerpc/mm/mmu_context.c | 99 ++++++++++++++++++++++++++++++++++ 3 files changed, 102 insertions(+), 88 deletions(-) create mode 100644 arch/powerpc/mm/mmu_context.c diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 2338abf..3095925 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -77,93 +77,8 @@ extern void switch_cop(struct mm_struct *next); extern int use_cop(unsigned long acop, struct mm_struct *mm); extern void drop_cop(unsigned long acop, struct mm_struct *mm); -#if defined(CONFIG_PPC32) -static inline void switch_mm_pgdir(struct task_struct *tsk, - struct mm_struct *mm) -{ - /* 32-bit keeps track of the current PGDIR in the thread struct */ - tsk->thread.pgdir = mm->pgd; -} -#elif defined(CONFIG_PPC_BOOK3E_64) -static inline void switch_mm_pgdir(struct task_struct *tsk, - struct mm_struct *mm) -{ - /* 64-bit Book3E keeps track of current PGD in the PACA */ - get_paca()->pgd = mm->pgd; -} -#else -static inline void switch_mm_pgdir(struct task_struct *tsk, - struct mm_struct *mm) { } -#endif - -#ifdef CONFIG_PPC_BOOK3S_64 -static inline void inc_mm_active_cpus(struct mm_struct *mm) -{ - atomic_inc(&mm->context.active_cpus); -} -#else -static inline void inc_mm_active_cpus(struct mm_struct *mm) { } -#endif - -/* - * switch_mm is the entry point called from the architecture independent - * code in kernel/sched/core.c - */ -static inline void switch_mm_irqs_off(struct mm_struct *prev, - struct mm_struct *next, - struct task_struct *tsk) -{ - bool new_on_cpu = false; - - /* Mark this context has been used on the new CPU */ - if (!cpumask_test_cpu(smp_processor_id(), mm_cpumask(next))) { - cpumask_set_cpu(smp_processor_id(), mm_cpumask(next)); - inc_mm_active_cpus(next); - - /* - * This full barrier orders the store to the cpumask above vs - * a subsequent operation which allows this CPU to begin loading - * translations for next. - * - * When using the radix MMU that operation is the load of the - * MMU context id, which is then moved to SPRN_PID. - * - * For the hash MMU it is either the first load from slb_cache - * in switch_slb(), and/or the store of paca->mm_ctx_id in - * copy_mm_to_paca(). - * - * On the read side the barrier is in pte_xchg(), which orders - * the store to the PTE vs the load of mm_cpumask. - */ - smp_mb(); - - new_on_cpu = true; - } - - /* Some subarchs need to track the PGD elsewhere */ - switch_mm_pgdir(tsk, next); - - /* Nothing else to do if we aren't actually switching */ - if (prev == next) - return; - - /* We must stop all altivec streams before changing the HW - * context - */ -#ifdef CONFIG_ALTIVEC - if (cpu_has_feature(CPU_FTR_ALTIVEC)) - asm volatile ("dssall"); -#endif /* CONFIG_ALTIVEC */ - - if (new_on_cpu) - radix_kvm_prefetch_workaround(next); - - /* - * The actual HW switching method differs between the various - * sub architectures. Out of line for now - */ - switch_mmu_context(prev, next, tsk); -} +extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk); static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk) diff --git a/arch/powerpc/mm/Makefile b/arch/powerpc/mm/Makefile index fa6a6ba..fb844d2 100644 --- a/arch/powerpc/mm/Makefile +++ b/arch/powerpc/mm/Makefile @@ -8,7 +8,7 @@ ccflags-$(CONFIG_PPC64) := $(NO_MINIMAL_TOC) obj-y := fault.o mem.o pgtable.o mmap.o \ init_$(BITS).o pgtable_$(BITS).o \ - init-common.o + init-common.o mmu_context.o obj-$(CONFIG_PPC_MMU_NOHASH) += mmu_context_nohash.o tlb_nohash.o \ tlb_nohash_low.o obj-$(CONFIG_PPC_BOOK3E) += tlb_low_$(BITS)e.o diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c new file mode 100644 index 0000000..0f613bc --- /dev/null +++ b/arch/powerpc/mm/mmu_context.c @@ -0,0 +1,99 @@ +/* + * Common implementation of switch_mm_irqs_off + * + * Copyright IBM Corp. 2017 + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + * + */ + +#include +#include + +#include + +#if defined(CONFIG_PPC32) +static inline void switch_mm_pgdir(struct task_struct *tsk, + struct mm_struct *mm) +{ + /* 32-bit keeps track of the current PGDIR in the thread struct */ + tsk->thread.pgdir = mm->pgd; +} +#elif defined(CONFIG_PPC_BOOK3E_64) +static inline void switch_mm_pgdir(struct task_struct *tsk, + struct mm_struct *mm) +{ + /* 64-bit Book3E keeps track of current PGD in the PACA */ + get_paca()->pgd = mm->pgd; +} +#else +static inline void switch_mm_pgdir(struct task_struct *tsk, + struct mm_struct *mm) { } +#endif + +#ifdef CONFIG_PPC_BOOK3S_64 +static inline void inc_mm_active_cpus(struct mm_struct *mm) +{ + atomic_inc(&mm->context.active_cpus); +} +#else +static inline void inc_mm_active_cpus(struct mm_struct *mm) { } +#endif + +void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk) +{ + bool new_on_cpu = false; + + /* Mark this context has been used on the new CPU */ + if (!cpumask_test_cpu(smp_processor_id(), mm_cpumask(next))) { + cpumask_set_cpu(smp_processor_id(), mm_cpumask(next)); + inc_mm_active_cpus(next); + + /* + * This full barrier orders the store to the cpumask above vs + * a subsequent operation which allows this CPU to begin loading + * translations for next. + * + * When using the radix MMU that operation is the load of the + * MMU context id, which is then moved to SPRN_PID. + * + * For the hash MMU it is either the first load from slb_cache + * in switch_slb(), and/or the store of paca->mm_ctx_id in + * copy_mm_to_paca(). + * + * On the read side the barrier is in pte_xchg(), which orders + * the store to the PTE vs the load of mm_cpumask. + */ + smp_mb(); + + new_on_cpu = true; + } + + /* Some subarchs need to track the PGD elsewhere */ + switch_mm_pgdir(tsk, next); + + /* Nothing else to do if we aren't actually switching */ + if (prev == next) + return; + + /* + * We must stop all altivec streams before changing the HW + * context + */ + if (cpu_has_feature(CPU_FTR_ALTIVEC)) + asm volatile ("dssall"); + + if (new_on_cpu) + radix_kvm_prefetch_workaround(next); + + /* + * The actual HW switching method differs between the various + * sub architectures. Out of line for now + */ + switch_mmu_context(prev, next, tsk); +} + -- 2.7.4