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/*
* MMU context allocation for 64-bit kernels.
*
* Copyright (C) 2004 Anton Blanchard, IBM Corp. <anton@samba.org>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*
*/
#include <linux/config.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/idr.h>
#include <asm/mmu_context.h>
static DEFINE_SPINLOCK(mmu_context_lock);
static DEFINE_IDR(mmu_context_idr);
int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
int index;
int err;
again:
if (!idr_pre_get(&mmu_context_idr, GFP_KERNEL))
return -ENOMEM;
spin_lock(&mmu_context_lock);
err = idr_get_new_above(&mmu_context_idr, NULL, 1, &index);
spin_unlock(&mmu_context_lock);
if (err == -EAGAIN)
goto again;
else if (err)
return err;
if (index > MAX_CONTEXT) {
idr_remove(&mmu_context_idr, index);
return -ENOMEM;
}
mm->context.id = index;
return 0;
}
void destroy_context(struct mm_struct *mm)
{
spin_lock(&mmu_context_lock);
idr_remove(&mmu_context_idr, mm->context.id);
spin_unlock(&mmu_context_lock);
mm->context.id = NO_CONTEXT;
}
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