mirror of https://gitee.com/openkylin/linux.git
88 lines
2.7 KiB
C
88 lines
2.7 KiB
C
/*
|
|
* 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
|