[linux-2.6-block.git] / include / asm-avr32 / mmu_context.h

/*
 * Copyright (C) 2004-2006 Atmel Corporation
 *
 * ASID handling taken from SH implementation.
 *   Copyright (C) 1999 Niibe Yutaka
 *   Copyright (C) 2003 Paul Mundt
 *
 * 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.
 */
#ifndef __ASM_AVR32_MMU_CONTEXT_H
#define __ASM_AVR32_MMU_CONTEXT_H

#include <asm/tlbflush.h>
#include <asm/pgalloc.h>
#include <asm/sysreg.h>
#include <asm-generic/mm_hooks.h>

/*
 * The MMU "context" consists of two things:
 *    (a) TLB cache version
 *    (b) ASID (Address Space IDentifier)
 */
#define MMU_CONTEXT_ASID_MASK		0x000000ff
#define MMU_CONTEXT_VERSION_MASK	0xffffff00
#define MMU_CONTEXT_FIRST_VERSION       0x00000100
#define NO_CONTEXT			0

#define MMU_NO_ASID			0x100

/* Virtual Page Number mask */
#define MMU_VPN_MASK	0xfffff000

/* Cache of MMU context last used */
extern unsigned long mmu_context_cache;

/*
 * Get MMU context if needed
 */
static inline void
get_mmu_context(struct mm_struct *mm)
{
	unsigned long mc = mmu_context_cache;

	if (((mm->context ^ mc) & MMU_CONTEXT_VERSION_MASK) == 0)
		/* It's up to date, do nothing */
		return;

	/* It's old, we need to get new context with new version */
	mc = ++mmu_context_cache;
	if (!(mc & MMU_CONTEXT_ASID_MASK)) {
		/*
		 * We have exhausted all ASIDs of this version.
		 * Flush the TLB and start new cycle.
		 */
		flush_tlb_all();
		/*
		 * Fix version. Note that we avoid version #0
		 * to distinguish NO_CONTEXT.
		 */
		if (!mc)
			mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
	}
	mm->context = mc;
}

/*
 * Initialize the context related info for a new mm_struct
 * instance.
 */
static inline int init_new_context(struct task_struct *tsk,
				       struct mm_struct *mm)
{
	mm->context = NO_CONTEXT;
	return 0;
}

/*
 * Destroy context related info for an mm_struct that is about
 * to be put to rest.
 */
static inline void destroy_context(struct mm_struct *mm)
{
	/* Do nothing */
}

static inline void set_asid(unsigned long asid)
{
	/* XXX: We're destroying TLBEHI[8:31] */
	sysreg_write(TLBEHI, asid & MMU_CONTEXT_ASID_MASK);
	cpu_sync_pipeline();
}

static inline unsigned long get_asid(void)
{
	unsigned long asid;

	asid = sysreg_read(TLBEHI);
	return asid & MMU_CONTEXT_ASID_MASK;
}

static inline void activate_context(struct mm_struct *mm)
{
	get_mmu_context(mm);
	set_asid(mm->context & MMU_CONTEXT_ASID_MASK);
}

static inline void switch_mm(struct mm_struct *prev,
				 struct mm_struct *next,
				 struct task_struct *tsk)
{
	if (likely(prev != next)) {
		unsigned long __pgdir = (unsigned long)next->pgd;

		sysreg_write(PTBR, __pgdir);
		activate_context(next);
	}
}

#define deactivate_mm(tsk,mm) do { } while(0)

#define activate_mm(prev, next) switch_mm((prev), (next), NULL)

static inline void
enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
{
}


static inline void enable_mmu(void)
{
	sysreg_write(MMUCR, (SYSREG_BIT(MMUCR_S)
			     | SYSREG_BIT(E)
			     | SYSREG_BIT(MMUCR_I)));
	nop(); nop(); nop(); nop(); nop(); nop(); nop(); nop();

	if (mmu_context_cache == NO_CONTEXT)
		mmu_context_cache = MMU_CONTEXT_FIRST_VERSION;

	set_asid(mmu_context_cache & MMU_CONTEXT_ASID_MASK);
}

static inline void disable_mmu(void)
{
	sysreg_write(MMUCR, SYSREG_BIT(MMUCR_S));
}

#endif /* __ASM_AVR32_MMU_CONTEXT_H */
Commit	Line	Data
5f97f7f9 HS	1	/*
	2	* Copyright (C) 2004-2006 Atmel Corporation
	3	*
	4	* ASID handling taken from SH implementation.
	5	* Copyright (C) 1999 Niibe Yutaka
	6	* Copyright (C) 2003 Paul Mundt
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12	#ifndef __ASM_AVR32_MMU_CONTEXT_H
	13	#define __ASM_AVR32_MMU_CONTEXT_H
	14
	15	#include <asm/tlbflush.h>
	16	#include <asm/pgalloc.h>
	17	#include <asm/sysreg.h>
d6dd61c8	18	#include <asm-generic/mm_hooks.h>
5f97f7f9 HS	19
	20	/*
	21	* The MMU "context" consists of two things:
	22	* (a) TLB cache version
	23	* (b) ASID (Address Space IDentifier)
	24	*/
	25	#define MMU_CONTEXT_ASID_MASK 0x000000ff
	26	#define MMU_CONTEXT_VERSION_MASK 0xffffff00
	27	#define MMU_CONTEXT_FIRST_VERSION 0x00000100
	28	#define NO_CONTEXT 0
	29
	30	#define MMU_NO_ASID 0x100
	31
	32	/* Virtual Page Number mask */
	33	#define MMU_VPN_MASK 0xfffff000
	34
	35	/* Cache of MMU context last used */
	36	extern unsigned long mmu_context_cache;
	37
	38	/*
	39	* Get MMU context if needed
	40	*/
	41	static inline void
	42	get_mmu_context(struct mm_struct *mm)
	43	{
	44	unsigned long mc = mmu_context_cache;
	45
	46	if (((mm->context ^ mc) & MMU_CONTEXT_VERSION_MASK) == 0)
	47	/* It's up to date, do nothing */
	48	return;
	49
	50	/* It's old, we need to get new context with new version */
	51	mc = ++mmu_context_cache;
	52	if (!(mc & MMU_CONTEXT_ASID_MASK)) {
	53	/*
	54	* We have exhausted all ASIDs of this version.
	55	* Flush the TLB and start new cycle.
	56	*/
	57	flush_tlb_all();
	58	/*
	59	* Fix version. Note that we avoid version #0
	60	* to distinguish NO_CONTEXT.
	61	*/
	62	if (!mc)
	63	mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
	64	}
	65	mm->context = mc;
	66	}
	67
	68	/*
	69	* Initialize the context related info for a new mm_struct
	70	* instance.
	71	*/
	72	static inline int init_new_context(struct task_struct *tsk,
	73	struct mm_struct *mm)
	74	{
	75	mm->context = NO_CONTEXT;
	76	return 0;
	77	}
	78
	79	/*
	80	* Destroy context related info for an mm_struct that is about
	81	* to be put to rest.
	82	*/
83	static inline void destroy_context(struct mm_struct *mm)
84	{
85	/* Do nothing */
86	}
87
88	static inline void set_asid(unsigned long asid)
89	{
90	/* XXX: We're destroying TLBEHI[8:31] */
91	sysreg_write(TLBEHI, asid & MMU_CONTEXT_ASID_MASK);
92	cpu_sync_pipeline();
93	}
94
95	static inline unsigned long get_asid(void)
96	{
97	unsigned long asid;
98
99	asid = sysreg_read(TLBEHI);
100	return asid & MMU_CONTEXT_ASID_MASK;
101	}
102
103	static inline void activate_context(struct mm_struct *mm)
104	{
105	get_mmu_context(mm);
106	set_asid(mm->context & MMU_CONTEXT_ASID_MASK);
107	}
108
109	static inline void switch_mm(struct mm_struct *prev,
110	struct mm_struct *next,
111	struct task_struct *tsk)
112	{
113	if (likely(prev != next)) {
114	unsigned long __pgdir = (unsigned long)next->pgd;
115
116	sysreg_write(PTBR, __pgdir);
117	activate_context(next);
118	}
119	}
120
121	#define deactivate_mm(tsk,mm) do { } while(0)
122
123	#define activate_mm(prev, next) switch_mm((prev), (next), NULL)
124
125	static inline void
126	enter_lazy_tlb(struct mm_struct mm, struct task_struct tsk)
127	{
128	}
129
130
131	static inline void enable_mmu(void)
132	{
133	sysreg_write(MMUCR, (SYSREG_BIT(MMUCR_S)
134	\| SYSREG_BIT(E)
135	\| SYSREG_BIT(MMUCR_I)));
136	nop(); nop(); nop(); nop(); nop(); nop(); nop(); nop();
137
138	if (mmu_context_cache == NO_CONTEXT)
139	mmu_context_cache = MMU_CONTEXT_FIRST_VERSION;
140
141	set_asid(mmu_context_cache & MMU_CONTEXT_ASID_MASK);
142	}
143
144	static inline void disable_mmu(void)
145	{
146	sysreg_write(MMUCR, SYSREG_BIT(MMUCR_S));
147	}
148
149	#endif /* __ASM_AVR32_MMU_CONTEXT_H */