#ifndef __I386_MMU_CONTEXT_H
#define __I386_MMU_CONTEXT_H
#include < linux/config.h>
#include < asm/desc.h>
#include < asm/atomic.h>
#include < asm/pgalloc.h>
/*
* possibly do the LDT unload here?
*/
#define destroy_context(mm) do { } while(0)
#define init_new_context(tsk,mm) 0
#ifdef CONFIG_SMP
static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk, unsigned cpu)
{
if(cpu_tlbstate[cpu].state == TLBSTATE_OK)
cpu_tlbstate[cpu].state = TLBSTATE_LAZY;
}
#else
static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk, unsigned cpu)
{
}
#endif
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, struct task_struct *tsk, unsigned cpu)
{
if (prev != next) {
/* stop flush ipis for the previous mm */
clear_bit(cpu, &prev->cpu_vm_mask);
/*
* Re-load LDT if necessary
*/
if (prev->context.segments != next->context.segments)
load_LDT(next);
#ifdef CONFIG_SMP
cpu_tlbstate[cpu].state = TLBSTATE_OK;
cpu_tlbstate[cpu].active_mm = next;
#endif
set_bit(cpu, &next->cpu_vm_mask);
set_bit(cpu, &next->context.cpuvalid);
/* Re-load page tables */
asm volatile("movl %0,%%cr3": :"r" (__pa(next->pgd))) ; //cxl: 进程的地址空间信息:进程的二级页表pgd
}
#ifdef CONFIG_SMP
else {
cpu_tlbstate[cpu].state = TLBSTATE_OK;
if(cpu_tlbstate[cpu].active_mm != next)
BUG();
if(!test_and_set_bit(cpu, &next->cpu_vm_mask)) {
/* We were in lazy tlb mode and leave_mm disabled
* tlb flush IPI delivery. We must flush our tlb.
*/
local_flush_tlb();
}
if (!test_and_set_bit(cpu, &next->context.cpuvalid))
load_LDT(next);
}
#endif
}
#define activate_mm(prev, next) \
switch_mm((prev),(next),NULL,smp_processor_id())
#endif