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 14 #ifndef _ASM_FIXMAP_H 15 #define _ASM_FIXMAP_H 16 17 #ifndef __ASSEMBLY__ 18 #include <linux/kernel.h> 19 #include <asm/page.h> 20 #ifdef CONFIG_HIGHMEM 21 #include <linux/threads.h> 22 #include <asm/kmap_types.h> 23 #endif 24 25 #define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE)) 26 27 /* 28 * Here we define all the compile-time 'special' virtual 29 * addresses. The point is to have a constant address at 30 * compile time, but to set the physical address only 31 * in the boot process. We allocate these special addresses 32 * from the end of virtual memory (0xfffff000) backwards. 33 * Also this lets us do fail-safe vmalloc(), we 34 * can guarantee that these special addresses and 35 * vmalloc()-ed addresses never overlap. 36 * 37 * these 'compile-time allocated' memory buffers are 38 * fixed-size 4k pages. (or larger if used with an increment 39 * highger than 1) use fixmap_set(idx,phys) to associate 40 * physical memory with fixmap indices. 41 * 42 * TLB entries of such buffers will not be flushed across 43 * task switches. 44 */ 45 enum fixed_addresses { 46 FIX_HOLE, 47 /* reserve the top 128K for early debugging purposes */ 48 FIX_EARLY_DEBUG_TOP = FIX_HOLE, 49 FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+((128*1024)/PAGE_SIZE)-1, 50 #ifdef CONFIG_HIGHMEM 51 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 52 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, 53 #endif 54 /* FIX_PCIE_MCFG, */ 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_NCG 65 66 #include <asm-generic/fixmap.h> 67 68 #endif /* !__ASSEMBLY__ */ 69 #endif 70