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Diffstat (limited to 'arch/mn10300/include/asm/mmu_context.h')
| -rw-r--r-- | arch/mn10300/include/asm/mmu_context.h | 163 |
1 files changed, 0 insertions, 163 deletions
diff --git a/arch/mn10300/include/asm/mmu_context.h b/arch/mn10300/include/asm/mmu_context.h deleted file mode 100644 index d2034f5e6eda..000000000000 --- a/arch/mn10300/include/asm/mmu_context.h +++ /dev/null @@ -1,163 +0,0 @@ -/* MN10300 MMU context management - * - * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. - * Modified by David Howells (dhowells@redhat.com) - * - Derived from include/asm-m32r/mmu_context.h - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public Licence - * as published by the Free Software Foundation; either version - * 2 of the Licence, or (at your option) any later version. - * - * - * This implements an algorithm to provide TLB PID mappings to provide - * selective access to the TLB for processes, thus reducing the number of TLB - * flushes required. - * - * Note, however, that the M32R algorithm is technically broken as it does not - * handle version wrap-around, and could, theoretically, have a problem with a - * very long lived program that sleeps long enough for the version number to - * wrap all the way around so that its TLB mappings appear valid once again. - */ -#ifndef _ASM_MMU_CONTEXT_H -#define _ASM_MMU_CONTEXT_H - -#include <linux/atomic.h> -#include <linux/mm_types.h> - -#include <asm/pgalloc.h> -#include <asm/tlbflush.h> -#include <asm-generic/mm_hooks.h> - -#define MMU_CONTEXT_TLBPID_NR 256 -#define MMU_CONTEXT_TLBPID_MASK 0x000000ffUL -#define MMU_CONTEXT_VERSION_MASK 0xffffff00UL -#define MMU_CONTEXT_FIRST_VERSION 0x00000100UL -#define MMU_NO_CONTEXT 0x00000000UL -#define MMU_CONTEXT_TLBPID_LOCK_NR 0 - -#define enter_lazy_tlb(mm, tsk) do {} while (0) - -static inline void cpu_ran_vm(int cpu, struct mm_struct *mm) -{ -#ifdef CONFIG_SMP - cpumask_set_cpu(cpu, mm_cpumask(mm)); -#endif -} - -static inline bool cpu_maybe_ran_vm(int cpu, struct mm_struct *mm) -{ -#ifdef CONFIG_SMP - return cpumask_test_and_set_cpu(cpu, mm_cpumask(mm)); -#else - return true; -#endif -} - -#ifdef CONFIG_MN10300_TLB_USE_PIDR -extern unsigned long mmu_context_cache[NR_CPUS]; -#define mm_context(mm) (mm->context.tlbpid[smp_processor_id()]) - -/** - * allocate_mmu_context - Allocate storage for the arch-specific MMU data - * @mm: The userspace VM context being set up - */ -static inline unsigned long allocate_mmu_context(struct mm_struct *mm) -{ - unsigned long *pmc = &mmu_context_cache[smp_processor_id()]; - unsigned long mc = ++(*pmc); - - if (!(mc & MMU_CONTEXT_TLBPID_MASK)) { - /* we exhausted the TLB PIDs of this version on this CPU, so we - * flush this CPU's TLB in its entirety and start new cycle */ - local_flush_tlb_all(); - - /* fix the TLB version if needed (we avoid version #0 so as to - * distinguish MMU_NO_CONTEXT) */ - if (!mc) - *pmc = mc = MMU_CONTEXT_FIRST_VERSION; - } - mm_context(mm) = mc; - return mc; -} - -/* - * get an MMU context if one is needed - */ -static inline unsigned long get_mmu_context(struct mm_struct *mm) -{ - unsigned long mc = MMU_NO_CONTEXT, cache; - - if (mm) { - cache = mmu_context_cache[smp_processor_id()]; - mc = mm_context(mm); - - /* if we have an old version of the context, replace it */ - if ((mc ^ cache) & MMU_CONTEXT_VERSION_MASK) - mc = allocate_mmu_context(mm); - } - return mc; -} - -/* - * initialise the context related info for a new mm_struct instance - */ -static inline int init_new_context(struct task_struct *tsk, - struct mm_struct *mm) -{ - int num_cpus = NR_CPUS, i; - - for (i = 0; i < num_cpus; i++) - mm->context.tlbpid[i] = MMU_NO_CONTEXT; - return 0; -} - -/* - * after we have set current->mm to a new value, this activates the context for - * the new mm so we see the new mappings. - */ -static inline void activate_context(struct mm_struct *mm) -{ - PIDR = get_mmu_context(mm) & MMU_CONTEXT_TLBPID_MASK; -} -#else /* CONFIG_MN10300_TLB_USE_PIDR */ - -#define init_new_context(tsk, mm) (0) -#define activate_context(mm) local_flush_tlb() - -#endif /* CONFIG_MN10300_TLB_USE_PIDR */ - -/** - * destroy_context - Destroy mm context information - * @mm: The MM being destroyed. - * - * Destroy context related info for an mm_struct that is about to be put to - * rest - */ -#define destroy_context(mm) do {} while (0) - -/** - * switch_mm - Change between userspace virtual memory contexts - * @prev: The outgoing MM context. - * @next: The incoming MM context. - * @tsk: The incoming task. - */ -static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, - struct task_struct *tsk) -{ - int cpu = smp_processor_id(); - - if (prev != next) { -#ifdef CONFIG_SMP - per_cpu(cpu_tlbstate, cpu).active_mm = next; -#endif - cpu_ran_vm(cpu, next); - PTBR = (unsigned long) next->pgd; - activate_context(next); - } -} - -#define deactivate_mm(tsk, mm) do {} while (0) -#define activate_mm(prev, next) switch_mm((prev), (next), NULL) - -#endif /* _ASM_MMU_CONTEXT_H */ |