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