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/sizes.h> 19 #include <asm/page.h> 20 #include <asm/pgtable.h> 21 #ifdef CONFIG_HIGHMEM 22 #include <linux/threads.h> 23 #include <asm/kmap_types.h> 24 #endif 25 26 #ifdef CONFIG_KASAN 27 #include <asm/kasan.h> 28 #define FIXADDR_TOP (KASAN_SHADOW_START - PAGE_SIZE) 29 #else 30 #define FIXADDR_TOP ((unsigned long)(-PAGE_SIZE)) 31 #endif 32 33 /* 34 * Here we define all the compile-time 'special' virtual 35 * addresses. The point is to have a constant address at 36 * compile time, but to set the physical address only 37 * in the boot process. We allocate these special addresses 38 * from the end of virtual memory (0xfffff000) backwards. 39 * Also this lets us do fail-safe vmalloc(), we 40 * can guarantee that these special addresses and 41 * vmalloc()-ed addresses never overlap. 42 * 43 * these 'compile-time allocated' memory buffers are 44 * fixed-size 4k pages. (or larger if used with an increment 45 * highger than 1) use fixmap_set(idx,phys) to associate 46 * physical memory with fixmap indices. 47 * 48 * TLB entries of such buffers will not be flushed across 49 * task switches. 50 */ 51 enum fixed_addresses { 52 FIX_HOLE, 53 /* reserve the top 128K for early debugging purposes */ 54 FIX_EARLY_DEBUG_TOP = FIX_HOLE, 55 FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+((128*1024)/PAGE_SIZE)-1, 56 #ifdef CONFIG_HIGHMEM 57 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 58 FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1, 59 #endif 60 #ifdef CONFIG_PPC_8xx 61 /* For IMMR we need an aligned 512K area */ 62 #define FIX_IMMR_SIZE (512 * 1024 / PAGE_SIZE) 63 FIX_IMMR_START, 64 FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 + 65 FIX_IMMR_SIZE, 66 #endif 67 #ifdef CONFIG_PPC_83xx 68 /* For IMMR we need an aligned 2M area */ 69 #define FIX_IMMR_SIZE (SZ_2M / PAGE_SIZE) 70 FIX_IMMR_START, 71 FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 + 72 FIX_IMMR_SIZE, 73 #endif 74 /* FIX_PCIE_MCFG, */ 75 __end_of_permanent_fixed_addresses, 76 77 #define NR_FIX_BTMAPS (SZ_256K / PAGE_SIZE) 78 #define FIX_BTMAPS_SLOTS 16 79 #define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS) 80 81 FIX_BTMAP_END = __end_of_permanent_fixed_addresses, 82 FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1, 83 __end_of_fixed_addresses 84 }; 85 86 #define __FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 87 #define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE) 88 89 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG 90 #define FIXMAP_PAGE_IO PAGE_KERNEL_NCG 91 92 #include <asm-generic/fixmap.h> 93 94 static inline void __set_fixmap(enum fixed_addresses idx, 95 phys_addr_t phys, pgprot_t flags) 96 { 97 if (__builtin_constant_p(idx)) 98 BUILD_BUG_ON(idx >= __end_of_fixed_addresses); 99 else if (WARN_ON(idx >= __end_of_fixed_addresses)) 100 return; 101 102 map_kernel_page(__fix_to_virt(idx), phys, flags); 103 } 104 105 #define __early_set_fixmap __set_fixmap 106 107 #endif /* !__ASSEMBLY__ */ 108 #endif 109