OpenRISC: Memory management

/*

 * OpenRISC Linux

 *

 * Linux architectural port borrowing liberally from similar works of

 * others.  All original copyrights apply as per the original source

 * declaration.

 *

 * OpenRISC implementation:

 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>

 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>

 * et al.

 *

 * 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.

 */

#ifndef __ASM_OPENRISC_CACHE_H

#define __ASM_OPENRISC_CACHE_H

/* FIXME: How can we replace these with values from the CPU...

 * they shouldn't be hard-coded!

 */

#define L1_CACHE_BYTES 16

#define L1_CACHE_SHIFT 4

#endif /* __ASM_OPENRISC_CACHE_H */

/*

 * OpenRISC Linux

 *

 * Linux architectural port borrowing liberally from similar works of

 * others.  All original copyrights apply as per the original source

 * declaration.

 *

 * OpenRISC implementation:

 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>

 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>

 * et al.

 *

 * 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.

 */

#ifndef __ASM_OPENRISC_FIXMAP_H

#define __ASM_OPENRISC_FIXMAP_H

/* Why exactly do we need 2 empty pages between the top of the fixed

 * addresses and the top of virtual memory?  Something is using that

 * memory space but not sure what right now... If you find it, leave

 * a comment here.

 */

#define FIXADDR_TOP	((unsigned long) (-2*PAGE_SIZE))

#include <linux/kernel.h>

#include <asm/page.h>

/*

 * On OpenRISC we use these special fixed_addresses for doing ioremap

 * early in the boot process before memory initialization is complete.

 * This is used, in particular, by the early serial console code.

 *

 * It's not really 'fixmap', per se, but fits loosely into the same

 * paradigm.

 */

enum fixed_addresses {

	/*

	 * FIX_IOREMAP entries are useful for mapping physical address

	 * space before ioremap() is useable, e.g. really early in boot

	 * before kmalloc() is working.

	 */

#define FIX_N_IOREMAPS  32

	FIX_IOREMAP_BEGIN,

	FIX_IOREMAP_END = FIX_IOREMAP_BEGIN + FIX_N_IOREMAPS - 1,

	__end_of_fixed_addresses

};

#define FIXADDR_SIZE		(__end_of_fixed_addresses << PAGE_SHIFT)

/* FIXADDR_BOTTOM might be a better name here... */

#define FIXADDR_START		(FIXADDR_TOP - FIXADDR_SIZE)

#define __fix_to_virt(x)	(FIXADDR_TOP - ((x) << PAGE_SHIFT))

#define __virt_to_fix(x)	((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)

/*

 * 'index to address' translation. If anyone tries to use the idx

 * directly without tranlation, we catch the bug with a NULL-deference

 * kernel oops. Illegal ranges of incoming indices are caught too.

 */

static __always_inline unsigned long fix_to_virt(const unsigned int idx)

{

	/*

	 * this branch gets completely eliminated after inlining,

	 * except when someone tries to use fixaddr indices in an

	 * illegal way. (such as mixing up address types or using

	 * out-of-range indices).

	 *

	 * If it doesn't get removed, the linker will complain

	 * loudly with a reasonably clear error message..

	 */

	if (idx >= __end_of_fixed_addresses)

		BUG();

	return __fix_to_virt(idx);

}

static inline unsigned long virt_to_fix(const unsigned long vaddr)

{

	BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START);

	return __virt_to_fix(vaddr);

}

#endif

/*

 * OpenRISC Linux

 *

 * Linux architectural port borrowing liberally from similar works of

 * others.  All original copyrights apply as per the original source

 * declaration.

 *

 * OpenRISC implementation:

 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>

 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>

 * et al.

 *

 * 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.

 */

#ifndef __ASM_OPENRISC_MEMBLOCK_H

#define __ASM_OPENRISC_MEMBLOCK_H

/* empty */

#endif /* __ASM_OPENRISC_MEMBLOCK_H */

/*

 * OpenRISC Linux

 *

 * Linux architectural port borrowing liberally from similar works of

 * others.  All original copyrights apply as per the original source

 * declaration.

 *

 * OpenRISC implementation:

 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>

 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>

 * et al.

 *

 * 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.

 */

#ifndef __ASM_OPENRISC_MMU_H

#define __ASM_OPENRISC_MMU_H

#ifndef __ASSEMBLY__

typedef unsigned long mm_context_t;

#endif

#endif

/*

 * OpenRISC Linux

 *

 * Linux architectural port borrowing liberally from similar works of

 * others.  All original copyrights apply as per the original source

 * declaration.

 *

 * OpenRISC implementation:

 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>

 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>

 * et al.

 *

 * 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.

 */

#ifndef __ASM_OPENRISC_MMU_CONTEXT_H

#define __ASM_OPENRISC_MMU_CONTEXT_H

#include <asm-generic/mm_hooks.h>

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

extern void destroy_context(struct mm_struct *mm);

extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,

		      struct task_struct *tsk);

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

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

/* current active pgd - this is similar to other processors pgd

 * registers like cr3 on the i386

 */

extern volatile pgd_t *current_pgd;   /* defined in arch/openrisc/mm/fault.c */

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

{

}

#endif