1 /* 2 * fixmap.h: compile-time virtual memory allocation 3 * 4 * This file is subject to the terms and conditions of the GNU General Public 5 * License. See the file "COPYING" in the main directory of this archive 6 * for more details. 7 * 8 * Copyright (C) 1998 Ingo Molnar 9 * 10 * Copyright 2008 Freescale Semiconductor Inc. 11 * Port to powerpc added by Kumar Gala 12 * 13 * Copyright 2011 Michal Simek <monstr@monstr.eu> 14 * Copyright 2011 PetaLogix Qld Pty Ltd 15 * Port to Microblaze 16 */ 17 18 #ifndef _ASM_FIXMAP_H 19 #define _ASM_FIXMAP_H 20 21 #ifndef __ASSEMBLY__ 22 #include <linux/kernel.h> 23 #include <asm/page.h> 24 #ifdef CONFIG_HIGHMEM 25 #include <linux/threads.h> 26 #include <asm/kmap_types.h> 27 #endif 28 29 #define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE)) 30 31 /* 32 * Here we define all the compile-time 'special' virtual 33 * addresses. The point is to have a constant address at 34 * compile time, but to set the physical address only 35 * in the boot process. We allocate these special addresses 36 * from the end of virtual memory (0xfffff000) backwards. 37 * Also this lets us do fail-safe vmalloc(), we 38 * can guarantee that these special addresses and 39 * vmalloc()-ed addresses never overlap. 40 * 41 * these 'compile-time allocated' memory buffers are 42 * fixed-size 4k pages. (or larger if used with an increment 43 * highger than 1) use fixmap_set(idx,phys) to associate 44 * physical memory with fixmap indices. 45 * 46 * TLB entries of such buffers will not be flushed across 47 * task switches. 48 */ 49 enum fixed_addresses { 50 FIX_HOLE, 51 #ifdef CONFIG_HIGHMEM 52 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 53 FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_TYPE_NR * num_possible_cpus()) - 1, 54 #endif 55 __end_of_fixed_addresses 56 }; 57 58 extern void __set_fixmap(enum fixed_addresses idx, 59 phys_addr_t phys, pgprot_t flags); 60 61 #define __FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 62 #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE) 63 64 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_CI 65 66 #include <asm-generic/fixmap.h> 67 68 #endif /* !__ASSEMBLY__ */ 69 #endif 70