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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Russell Kingd84b4712006-08-21 19:23:38 +01002 * linux/arch/arm/mm/context.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Copyright (C) 2002-2003 Deep Blue Solutions Ltd, all rights reserved.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10#include <linux/init.h>
11#include <linux/sched.h>
12#include <linux/mm.h>
13
14#include <asm/mmu_context.h>
15#include <asm/tlbflush.h>
16
17unsigned int cpu_last_asid = { 1 << ASID_BITS };
18
19/*
20 * We fork()ed a process, and we need a new context for the child
21 * to run in. We reserve version 0 for initial tasks so we will
22 * always allocate an ASID.
23 */
24void __init_new_context(struct task_struct *tsk, struct mm_struct *mm)
25{
26 mm->context.id = 0;
27}
28
29void __new_context(struct mm_struct *mm)
30{
31 unsigned int asid;
32
33 asid = ++cpu_last_asid;
34 if (asid == 0)
35 asid = cpu_last_asid = 1 << ASID_BITS;
36
37 /*
38 * If we've used up all our ASIDs, we need
39 * to start a new version and flush the TLB.
40 */
41 if ((asid & ~ASID_MASK) == 0)
42 flush_tlb_all();
43
44 mm->context.id = asid;
45}