1 /* 2 * linux/arch/arm/mm/mmu.c 3 * 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 17 unsigned 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 */ 24 void __init_new_context(struct task_struct *tsk, struct mm_struct *mm) 25 { 26 mm->context.id = 0; 27 } 28 29 void __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 } 46