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- /*
- * linux/arch/arm/mm/context.c
- *
- * Copyright (C) 2002-2003 Deep Blue Solutions Ltd, all rights reserved.
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License version 2 as
- * published by the Free Software Foundation.
- */
- #include <linux/init.h>
- #include <linux/sched.h>
- #include <linux/mm.h>
- #include <asm/mmu_context.h>
- #include <asm/tlbflush.h>
- unsigned int cpu_last_asid = { 1 << ASID_BITS };
- /*
- * We fork()ed a process, and we need a new context for the child
- * to run in. We reserve version 0 for initial tasks so we will
- * always allocate an ASID. The ASID 0 is reserved for the TTBR
- * register changing sequence.
- */
- void __init_new_context(struct task_struct *tsk, struct mm_struct *mm)
- {
- mm->context.id = 0;
- }
- void __new_context(struct mm_struct *mm)
- {
- unsigned int asid;
- asid = ++cpu_last_asid;
- if (asid == 0)
- asid = cpu_last_asid = 1 << ASID_BITS;
- /*
- * If we've used up all our ASIDs, we need
- * to start a new version and flush the TLB.
- */
- if ((asid & ~ASID_MASK) == 0) {
- asid = ++cpu_last_asid;
- /* set the reserved ASID before flushing the TLB */
- asm("mcr p15, 0, %0, c13, c0, 1 @ set reserved context ID\n"
- :
- : "r" (0));
- isb();
- flush_tlb_all();
- }
- mm->context.id = asid;
- }
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