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/*
* Copyright (C) 1998 Ingo Molnar
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* 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, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/
#ifndef _ASM_TILE_FIXMAP_H
#define _ASM_TILE_FIXMAP_H
#include <asm/page.h>
#ifndef __ASSEMBLY__
#include <linux/kernel.h>
#ifdef CONFIG_HIGHMEM
#include <linux/threads.h>
#include <asm/kmap_types.h>
#endif
#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT))
#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT)
/*
* Here we define all the compile-time 'special' virtual
* addresses. The point is to have a constant address at
* compile time, but to set the physical address only
* in the boot process. We allocate these special addresses
* from the end of supervisor virtual memory backwards.
* Also this lets us do fail-safe vmalloc(), we
* can guarantee that these special addresses and
* vmalloc()-ed addresses never overlap.
*
* these 'compile-time allocated' memory buffers are
* fixed-size 4k pages. (or larger if used with an increment
* higher than 1) use fixmap_set(idx,phys) to associate
* physical memory with fixmap indices.
*
* TLB entries of such buffers will not be flushed across
* task switches.
*/
enum fixed_addresses {
#ifdef __tilegx__
/*
* TILEPro has unmapped memory above so the hole isn't needed,
* and in any case the hole pushes us over a single 16MB pmd.
*/
FIX_HOLE,
#endif
#ifdef CONFIG_HIGHMEM
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
#endif
#ifdef __tilegx__ /* see homecache.c */
FIX_HOMECACHE_BEGIN,
FIX_HOMECACHE_END = FIX_HOMECACHE_BEGIN+(NR_CPUS)-1,
#endif
__end_of_permanent_fixed_addresses,
/*
* Temporary boot-time mappings, used before ioremap() is functional.
* Not currently needed by the Tile architecture.
*/
#define NR_FIX_BTMAPS 0
#if NR_FIX_BTMAPS
FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
FIX_BTMAP_BEGIN = FIX_BTMAP_END + NR_FIX_BTMAPS - 1,
__end_of_fixed_addresses
#else
__end_of_fixed_addresses = __end_of_permanent_fixed_addresses
#endif
};
#define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
#define __FIXADDR_BOOT_SIZE (__end_of_fixed_addresses << PAGE_SHIFT)
#define FIXADDR_START (FIXADDR_TOP + PAGE_SIZE - __FIXADDR_SIZE)
#define FIXADDR_BOOT_START (FIXADDR_TOP + PAGE_SIZE - __FIXADDR_BOOT_SIZE)
extern void __this_fixmap_does_not_exist(void);
/*
* '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)
__this_fixmap_does_not_exist();
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 /* !__ASSEMBLY__ */
#endif /* _ASM_TILE_FIXMAP_H */
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