diff options
author | Arjan van de Ven <arjan@linux.intel.com> | 2008-10-17 09:20:26 -0700 |
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committer | Arjan van de Ven <arjan@linux.intel.com> | 2008-10-17 09:20:26 -0700 |
commit | 651dab4264e4ba0e563f5ff56f748127246e9065 (patch) | |
tree | 016630974bdcb00fe529b673f96d389e0fd6dc94 /arch/mips/include/asm/fixmap.h | |
parent | 40b8606253552109815786e5d4b0de98782d31f5 (diff) | |
parent | 2e532d68a2b3e2aa6b19731501222069735c741c (diff) |
Merge commit 'linus/master' into merge-linus
Conflicts:
arch/x86/kvm/i8254.c
Diffstat (limited to 'arch/mips/include/asm/fixmap.h')
-rw-r--r-- | arch/mips/include/asm/fixmap.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/arch/mips/include/asm/fixmap.h b/arch/mips/include/asm/fixmap.h new file mode 100644 index 00000000000..9cc8522a394 --- /dev/null +++ b/arch/mips/include/asm/fixmap.h @@ -0,0 +1,118 @@ +/* + * fixmap.h: compile-time virtual memory allocation + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 1998 Ingo Molnar + * + * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 + */ + +#ifndef _ASM_FIXMAP_H +#define _ASM_FIXMAP_H + +#include <asm/page.h> +#ifdef CONFIG_HIGHMEM +#include <linux/threads.h> +#include <asm/kmap_types.h> +#endif + +/* + * 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 virtual memory (0xfffff000) 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 + * highger 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. + */ + +/* + * on UP currently we will have no trace of the fixmap mechanizm, + * no page table allocations, etc. This might change in the + * future, say framebuffers for the console driver(s) could be + * fix-mapped? + */ +enum fixed_addresses { +#define FIX_N_COLOURS 8 + FIX_CMAP_BEGIN, +#ifdef CONFIG_MIPS_MT_SMTC + FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * NR_CPUS), +#else + FIX_CMAP_END = FIX_CMAP_BEGIN + FIX_N_COLOURS, +#endif +#ifdef CONFIG_HIGHMEM + /* reserved pte's for temporary kernel mappings */ + FIX_KMAP_BEGIN = FIX_CMAP_END + 1, + FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, +#endif + __end_of_fixed_addresses +}; + +/* + * used by vmalloc.c. + * + * Leave one empty page between vmalloc'ed areas and + * the start of the fixmap, and leave one page empty + * at the top of mem.. + */ +#if defined(CONFIG_CPU_TX39XX) || defined(CONFIG_CPU_TX49XX) +#define FIXADDR_TOP ((unsigned long)(long)(int)(0xff000000 - 0x20000)) +#else +#define FIXADDR_TOP ((unsigned long)(long)(int)0xfffe0000) +#endif +#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) +#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) + +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 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); +} + +/* + * Called from pgtable_init() + */ +extern void fixrange_init(unsigned long start, unsigned long end, + pgd_t *pgd_base); + + +#endif |