diff options
Diffstat (limited to 'arch/tile/include/asm/fixmap.h')
| -rw-r--r-- | arch/tile/include/asm/fixmap.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/tile/include/asm/fixmap.h b/arch/tile/include/asm/fixmap.h new file mode 100644 index 00000000..c66f7933 --- /dev/null +++ b/arch/tile/include/asm/fixmap.h @@ -0,0 +1,118 @@ +/* + * 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. + * + * We don't bother with a FIX_HOLE since above the fixmaps + * is unmapped memory in any case. + */ +enum fixed_addresses { +#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 + __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 +}; + +extern void __set_fixmap(enum fixed_addresses idx, + unsigned long phys, pgprot_t flags); + +#define set_fixmap(idx, phys) \ + __set_fixmap(idx, phys, PAGE_KERNEL) +#define clear_fixmap(idx) \ + __set_fixmap(idx, 0, __pgprot(0)) + +#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 */ |