107 lines
2.7 KiB
C
107 lines
2.7 KiB
C
/*
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* linux/arch/unicore32/include/asm/mmu_context.h
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*
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* Code specific to PKUnity SoC and UniCore ISA
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*
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* Copyright (C) 2001-2010 GUAN Xue-tao
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#ifndef __UNICORE_MMU_CONTEXT_H__
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#define __UNICORE_MMU_CONTEXT_H__
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#include <linux/compiler.h>
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#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/vmacache.h>
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#include <linux/io.h>
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#include <asm/cacheflush.h>
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#include <asm/cpu-single.h>
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#define init_new_context(tsk, mm) 0
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#define destroy_context(mm) do { } while (0)
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/*
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* This is called when "tsk" is about to enter lazy TLB mode.
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*
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* mm: describes the currently active mm context
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* tsk: task which is entering lazy tlb
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* cpu: cpu number which is entering lazy tlb
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*
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* tsk->mm will be NULL
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*/
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static inline void
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enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
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{
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}
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/*
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* This is the actual mm switch as far as the scheduler
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* is concerned. No registers are touched. We avoid
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* calling the CPU specific function when the mm hasn't
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* actually changed.
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*/
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static inline void
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switch_mm(struct mm_struct *prev, struct mm_struct *next,
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struct task_struct *tsk)
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{
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unsigned int cpu = smp_processor_id();
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if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next)
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cpu_switch_mm(next->pgd, next);
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}
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#define deactivate_mm(tsk, mm) do { } while (0)
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#define activate_mm(prev, next) switch_mm(prev, next, NULL)
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/*
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* We are inserting a "fake" vma for the user-accessible vector page so
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* gdb and friends can get to it through ptrace and /proc/<pid>/mem.
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* But we also want to remove it before the generic code gets to see it
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* during process exit or the unmapping of it would cause total havoc.
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* (the macro is used as remove_vma() is static to mm/mmap.c)
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*/
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#define arch_exit_mmap(mm) \
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do { \
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struct vm_area_struct *high_vma = find_vma(mm, 0xffff0000); \
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if (high_vma) { \
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BUG_ON(high_vma->vm_next); /* it should be last */ \
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if (high_vma->vm_prev) \
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high_vma->vm_prev->vm_next = NULL; \
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else \
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mm->mmap = NULL; \
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rb_erase(&high_vma->vm_rb, &mm->mm_rb); \
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vmacache_invalidate(mm); \
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mm->map_count--; \
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remove_vma(high_vma); \
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} \
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} while (0)
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static inline int arch_dup_mmap(struct mm_struct *oldmm,
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struct mm_struct *mm)
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{
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return 0;
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}
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static inline void arch_unmap(struct mm_struct *mm,
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unsigned long start, unsigned long end)
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{
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}
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static inline void arch_bprm_mm_init(struct mm_struct *mm,
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struct vm_area_struct *vma)
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{
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}
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static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
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bool write, bool execute, bool foreign)
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{
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/* by default, allow everything */
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return true;
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}
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#endif
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