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 <asm/page.h> 19 #include <asm/pgtable.h> 20 #ifdef CONFIG_HIGHMEM 21 #include <linux/threads.h> 22 #include <asm/kmap_types.h> 23 #endif 24 25 #ifdef CONFIG_KASAN 26 #include <asm/kasan.h> 27 #define FIXADDR_TOP (KASAN_SHADOW_START - PAGE_SIZE) 28 #else 29 #define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE)) 30 #endif 31 32 /* 33 * Here we define all the compile-time 'special' virtual 34 * addresses. The point is to have a constant address at 35 * compile time, but to set the physical address only 36 * in the boot process. We allocate these special addresses 37 * from the end of virtual memory (0xfffff000) backwards. 38 * Also this lets us do fail-safe vmalloc(), we 39 * can guarantee that these special addresses and 40 * vmalloc()-ed addresses never overlap. 41 * 42 * these 'compile-time allocated' memory buffers are 43 * fixed-size 4k pages. (or larger if used with an increment 44 * highger than 1) use fixmap_set(idx,phys) to associate 45 * physical memory with fixmap indices. 46 * 47 * TLB entries of such buffers will not be flushed across 48 * task switches. 49 */ 50 enum fixed_addresses { 51 FIX_HOLE, 52 /* reserve the top 128K for early debugging purposes */ 53 FIX_EARLY_DEBUG_TOP = FIX_HOLE, 54 FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+((128*1024)/PAGE_SIZE)-1, 55 #ifdef CONFIG_HIGHMEM 56 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 57 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, 58 #endif 59 #ifdef CONFIG_PPC_8xx 60 /* For IMMR we need an aligned 512K area */ 61 #define FIX_IMMR_SIZE (512 * 1024 / PAGE_SIZE) 62 FIX_IMMR_START, 63 FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 + 64 FIX_IMMR_SIZE, 65 #endif 66 /* FIX_PCIE_MCFG, */ 67 __end_of_fixed_addresses 68 }; 69 70 #define __FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 71 #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE) 72 73 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG 74 75 #include <asm-generic/fixmap.h> 76 77 static inline void __set_fixmap(enum fixed_addresses idx, 78 phys_addr_t phys, pgprot_t flags) 79 { 80 map_kernel_page(fix_to_virt(idx), phys, flags); 81 } 82 83 #endif /* !__ASSEMBLY__ */ 84 #endif 85