/* * 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>#include <spaces.h>#ifdef CONFIG_HIGHMEM#include <linux/threads.h>#include <asm/kmap_size.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,	FIX_CMAP_END = FIX_CMAP_BEGIN + (FIX_N_COLOURS * 2),#ifdef CONFIG_HIGHMEM	/* reserved pte's for temporary kernel mappings */	FIX_KMAP_BEGIN = FIX_CMAP_END + 1,	FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * 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.. */#define FIXADDR_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)#define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE) #include <asm-generic/fixmap.h> /* * Called from pagetable_init() */extern void fixrange_init(unsigned long start, unsigned long end,	pgd_t *pgd_base);  #endif