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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* linux/arch/unicore32/include/asm/mmu_context.h
*
* Code specific to PKUnity SoC and UniCore ISA
*
* Copyright (C) 2001-2010 GUAN Xue-tao
*/
#ifndef __UNICORE_MMU_CONTEXT_H__
#define __UNICORE_MMU_CONTEXT_H__
#include <linux/compiler.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/vmacache.h>
#include <linux/io.h>
#include <asm/cacheflush.h>
#include <asm/cpu-single.h>
#define init_new_context(tsk, mm) 0
#define destroy_context(mm) do { } while (0)
/*
* This is called when "tsk" is about to enter lazy TLB mode.
*
* mm: describes the currently active mm context
* tsk: task which is entering lazy tlb
* cpu: cpu number which is entering lazy tlb
*
* tsk->mm will be NULL
*/
static inline void
enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
}
/*
* This is the actual mm switch as far as the scheduler
* is concerned. No registers are touched. We avoid
* calling the CPU specific function when the mm hasn't
* actually changed.
*/
static inline void
switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
unsigned int cpu = smp_processor_id();
if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next)
cpu_switch_mm(next->pgd, next);
}
#define deactivate_mm(tsk, mm) do { } while (0)
#define activate_mm(prev, next) switch_mm(prev, next, NULL)
/*
* We are inserting a "fake" vma for the user-accessible vector page so
* gdb and friends can get to it through ptrace and /proc/<pid>/mem.
* But we also want to remove it before the generic code gets to see it
* during process exit or the unmapping of it would cause total havoc.
* (the macro is used as remove_vma() is static to mm/mmap.c)
*/
#define arch_exit_mmap(mm) \
do { \
struct vm_area_struct *high_vma = find_vma(mm, 0xffff0000); \
if (high_vma) { \
BUG_ON(high_vma->vm_next); /* it should be last */ \
if (high_vma->vm_prev) \
high_vma->vm_prev->vm_next = NULL; \
else \
mm->mmap = NULL; \
rb_erase(&high_vma->vm_rb, &mm->mm_rb); \
vmacache_invalidate(mm); \
mm->map_count--; \
remove_vma(high_vma); \
} \
} while (0)
static inline int arch_dup_mmap(struct mm_struct *oldmm,
struct mm_struct *mm)
{
return 0;
}
static inline void arch_unmap(struct mm_struct *mm,
unsigned long start, unsigned long end)
{
}
static inline void arch_bprm_mm_init(struct mm_struct *mm,
struct vm_area_struct *vma)
{
}
static inline bool arch_vma_access_permitted(struct vm_area_struct *vma,
bool write, bool execute, bool foreign)
{
/* by default, allow everything */
return true;
}
#endif
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