projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 | 1 | /* |
| d84b4711 | 2 | * linux/arch/arm/mm/context.c |
| 1da177e4 LT |
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 | } |