1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * fixmap.h: compile-time virtual memory allocation 4 * 5 * Copyright (C) 1998 Ingo Molnar 6 * 7 * Copyright 2008 Freescale Semiconductor Inc. 8 * Port to powerpc added by Kumar Gala 9 * 10 * Copyright 2011 Michal Simek <monstr@monstr.eu> 11 * Copyright 2011 PetaLogix Qld Pty Ltd 12 * Port to Microblaze 13 */ 14 15#ifndef _ASM_FIXMAP_H 16#define _ASM_FIXMAP_H 17 18#ifndef __ASSEMBLY__ 19#include <linux/kernel.h> 20#include <asm/page.h> 21#ifdef CONFIG_HIGHMEM 22#include <linux/threads.h> 23#include <asm/kmap_size.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 */ 46enum fixed_addresses { 47 FIX_HOLE, 48#ifdef CONFIG_HIGHMEM 49 FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */ 50 FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * num_possible_cpus()) - 1, 51#endif 52 __end_of_fixed_addresses 53}; 54 55extern void __set_fixmap(enum fixed_addresses idx, 56 phys_addr_t phys, pgprot_t flags); 57 58#define __FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) 59#define FIXADDR_START (FIXADDR_TOP - __FIXADDR_SIZE) 60 61#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_CI 62 63#include <asm-generic/fixmap.h> 64 65#endif /* !__ASSEMBLY__ */ 66#endif 67