[deliverable/linux.git] / arch / powerpc / mm / mmu_context_hash64.c

/*
 *  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/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 <linux/export.h>
#include <linux/gfp.h>
#include <linux/slab.h>

#include <asm/mmu_context.h>

#include "icswx.h"

static DEFINE_SPINLOCK(mmu_context_lock);
static DEFINE_IDA(mmu_context_ida);

int __init_new_context(void)
{
	int index;
	int err;

again:
	if (!ida_pre_get(&mmu_context_ida, GFP_KERNEL))
		return -ENOMEM;

	spin_lock(&mmu_context_lock);
	err = ida_get_new_above(&mmu_context_ida, 1, &index);
	spin_unlock(&mmu_context_lock);

	if (err == -EAGAIN)
		goto again;
	else if (err)
		return err;

	if (index > MAX_USER_CONTEXT) {
		spin_lock(&mmu_context_lock);
		ida_remove(&mmu_context_ida, index);
		spin_unlock(&mmu_context_lock);
		return -ENOMEM;
	}

	return index;
}
EXPORT_SYMBOL_GPL(__init_new_context);

int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
	int index;

	index = __init_new_context();
	if (index < 0)
		return index;

	/* The old code would re-promote on fork, we don't do that
	 * when using slices as it could cause problem promoting slices
	 * that have been forced down to 4K
	 */
	if (slice_mm_new_context(mm))
		slice_set_user_psize(mm, mmu_virtual_psize);
	subpage_prot_init_new_context(mm);
	mm->context.id = index;
#ifdef CONFIG_PPC_ICSWX
	mm->context.cop_lockp = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
	if (!mm->context.cop_lockp) {
		__destroy_context(index);
		subpage_prot_free(mm);
		mm->context.id = MMU_NO_CONTEXT;
		return -ENOMEM;
	}
	spin_lock_init(mm->context.cop_lockp);
#endif /* CONFIG_PPC_ICSWX */

	return 0;
}

void __destroy_context(int context_id)
{
	spin_lock(&mmu_context_lock);
	ida_remove(&mmu_context_ida, context_id);
	spin_unlock(&mmu_context_lock);
}
EXPORT_SYMBOL_GPL(__destroy_context);

void destroy_context(struct mm_struct *mm)
{
#ifdef CONFIG_PPC_ICSWX
	drop_cop(mm->context.acop, mm);
	kfree(mm->context.cop_lockp);
	mm->context.cop_lockp = NULL;
#endif /* CONFIG_PPC_ICSWX */
	__destroy_context(mm->context.id);
	subpage_prot_free(mm);
	mm->context.id = MMU_NO_CONTEXT;
}
Commit	Line	Data
14cf11af PM	1	/*
	2	* MMU context allocation for 64-bit kernels.
	3	*
	4	* Copyright (C) 2004 Anton Blanchard, IBM Corp. <anton@samba.org>
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public License
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the License, or (at your option) any later version.
	10	*
	11	*/
	12
14cf11af PM	13	#include <linux/sched.h>
	14	#include <linux/kernel.h>
	15	#include <linux/errno.h>
	16	#include <linux/string.h>
	17	#include <linux/types.h>
	18	#include <linux/mm.h>
	19	#include <linux/spinlock.h>
	20	#include <linux/idr.h>
4b16f8e2	21	#include <linux/export.h>
5a0e3ad6	22	#include <linux/gfp.h>
851d2e2f	23	#include <linux/slab.h>
14cf11af PM	24
	25	#include <asm/mmu_context.h>
	26
9d670280	27	#include "icswx.h"
851d2e2f	28
14cf11af	29	static DEFINE_SPINLOCK(mmu_context_lock);
7317ac87	30	static DEFINE_IDA(mmu_context_ida);
14cf11af	31
e85a4710	32	int __init_new_context(void)
14cf11af PM	33	{
	34	int index;
	35	int err;
	36
	37	again:
7317ac87	38	if (!ida_pre_get(&mmu_context_ida, GFP_KERNEL))
14cf11af PM	39	return -ENOMEM;
	40
	41	spin_lock(&mmu_context_lock);
7317ac87	42	err = ida_get_new_above(&mmu_context_ida, 1, &index);
14cf11af PM	43	spin_unlock(&mmu_context_lock);
	44
	45	if (err == -EAGAIN)
	46	goto again;
	47	else if (err)
	48	return err;
	49
c60ac569	50	if (index > MAX_USER_CONTEXT) {
f86c9747	51	spin_lock(&mmu_context_lock);
7317ac87	52	ida_remove(&mmu_context_ida, index);
f86c9747	53	spin_unlock(&mmu_context_lock);
14cf11af PM	54	return -ENOMEM;
	55	}
	56
e85a4710 AG	57	return index;
	58	}
	59	EXPORT_SYMBOL_GPL(__init_new_context);
	60
	61	int init_new_context(struct task_struct tsk, struct mm_struct mm)
	62	{
	63	int index;
	64
	65	index = __init_new_context();
	66	if (index < 0)
	67	return index;
	68
d0f13e3c BH	69	/* The old code would re-promote on fork, we don't do that
	70	* when using slices as it could cause problem promoting slices
	71	* that have been forced down to 4K
	72	*/
e8ff0646	73	if (slice_mm_new_context(mm))
d0f13e3c	74	slice_set_user_psize(mm, mmu_virtual_psize);
d28513bc	75	subpage_prot_init_new_context(mm);
9dfe5c53	76	mm->context.id = index;
851d2e2f THFL	77	#ifdef CONFIG_PPC_ICSWX
	78	mm->context.cop_lockp = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
	79	if (!mm->context.cop_lockp) {
	80	__destroy_context(index);
	81	subpage_prot_free(mm);
79af2187	82	mm->context.id = MMU_NO_CONTEXT;
851d2e2f THFL	83	return -ENOMEM;
	84	}
	85	spin_lock_init(mm->context.cop_lockp);
	86	#endif /* CONFIG_PPC_ICSWX */
14cf11af PM	87
	88	return 0;
	89	}
	90
e85a4710	91	void __destroy_context(int context_id)
14cf11af PM	92	{
14cf11af PM	93	spin_lock(&mmu_context_lock);
7317ac87	94	ida_remove(&mmu_context_ida, context_id);
14cf11af	95	spin_unlock(&mmu_context_lock);
e85a4710 AG	96	}
e85a4710 AG	97	EXPORT_SYMBOL_GPL(__destroy_context);
14cf11af	98
e85a4710 AG	99	void destroy_context(struct mm_struct *mm)
e85a4710 AG	100	{
851d2e2f THFL	101	#ifdef CONFIG_PPC_ICSWX
	102	drop_cop(mm->context.acop, mm);
	103	kfree(mm->context.cop_lockp);
	104	mm->context.cop_lockp = NULL;
	105	#endif /* CONFIG_PPC_ICSWX */
e85a4710	106	__destroy_context(mm->context.id);
d28513bc	107	subpage_prot_free(mm);
5e8e7b40	108	mm->context.id = MMU_NO_CONTEXT;
14cf11af	109	}