fixmap.h

  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 * Copyright (C) 2013 Mark Salter <msalter@redhat.com>
 10 *
 11 * Adapted from arch/x86 version.
 12 *
 13 */
 14
 15#ifndef _ASM_ARM64_FIXMAP_H
 16#define _ASM_ARM64_FIXMAP_H
 17
 18#ifndef __ASSEMBLER__
 19#include <linux/kernel.h>
 20#include <linux/math.h>
 21#include <linux/sizes.h>
 22#include <asm/boot.h>
 23#include <asm/page.h>
 24#include <asm/pgtable-prot.h>
 25
 26/*
 27 * Here we define all the compile-time 'special' virtual
 28 * addresses. The point is to have a constant address at
 29 * compile time, but to set the physical address only
 30 * in the boot process.
 31 *
 32 * Each enum increment in these 'compile-time allocated'
 33 * memory buffers is page-sized. Use set_fixmap(idx,phys)
 34 * to associate physical memory with a fixmap index.
 35 */
 36enum fixed_addresses {
 37	FIX_HOLE,
 38
 39	/*
 40	 * Reserve a virtual window for the FDT that is a page bigger than the
 41	 * maximum supported size. The additional space ensures that any FDT
 42	 * that does not exceed MAX_FDT_SIZE can be mapped regardless of
 43	 * whether it crosses any page boundary.
 44	 */
 45	FIX_FDT_END,
 46	FIX_FDT = FIX_FDT_END + DIV_ROUND_UP(MAX_FDT_SIZE, PAGE_SIZE) + 1,
 47
 48	FIX_EARLYCON_MEM_BASE,
 49	FIX_TEXT_POKE0,
 50
 51#ifdef CONFIG_KVM
 52	/* One slot per CPU, mapping the guest's VNCR page at EL2. */
 53	FIX_VNCR_END,
 54	FIX_VNCR = FIX_VNCR_END + NR_CPUS,
 55#endif
 56
 57#ifdef CONFIG_ACPI_APEI_GHES
 58	/* Used for GHES mapping from assorted contexts */
 59	FIX_APEI_GHES_IRQ,
 60	FIX_APEI_GHES_SEA,
 61#ifdef CONFIG_ARM_SDE_INTERFACE
 62	FIX_APEI_GHES_SDEI_NORMAL,
 63	FIX_APEI_GHES_SDEI_CRITICAL,
 64#endif
 65#endif /* CONFIG_ACPI_APEI_GHES */
 66
 67#ifdef CONFIG_UNMAP_KERNEL_AT_EL0
 68#ifdef CONFIG_RELOCATABLE
 69	FIX_ENTRY_TRAMP_TEXT4,	/* one extra slot for the data page */
 70#endif
 71	FIX_ENTRY_TRAMP_TEXT3,
 72	FIX_ENTRY_TRAMP_TEXT2,
 73	FIX_ENTRY_TRAMP_TEXT1,
 74#define TRAMP_VALIAS		(__fix_to_virt(FIX_ENTRY_TRAMP_TEXT1))
 75#endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
 76	__end_of_permanent_fixed_addresses,
 77
 78	/*
 79	 * Temporary boot-time mappings, used by early_ioremap(),
 80	 * before ioremap() is functional.
 81	 */
 82#define NR_FIX_BTMAPS		(SZ_256K / PAGE_SIZE)
 83#define FIX_BTMAPS_SLOTS	7
 84#define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
 85
 86	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
 87	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
 88
 89	/*
 90	 * Used for kernel page table creation, so unmapped memory may be used
 91	 * for tables.
 92	 */
 93	FIX_PTE,
 94	FIX_PMD,
 95	FIX_PUD,
 96	FIX_P4D,
 97	FIX_PGD,
 98
 99	__end_of_fixed_addresses
100};
101
102#define FIXADDR_SIZE		(__end_of_permanent_fixed_addresses << PAGE_SHIFT)
103#define FIXADDR_START		(FIXADDR_TOP - FIXADDR_SIZE)
104#define FIXADDR_TOT_SIZE	(__end_of_fixed_addresses << PAGE_SHIFT)
105#define FIXADDR_TOT_START	(FIXADDR_TOP - FIXADDR_TOT_SIZE)
106
107#define FIXMAP_PAGE_IO     __pgprot(PROT_DEVICE_nGnRE)
108
109void __init early_fixmap_init(void);
110
111#define __early_set_fixmap __set_fixmap
112
113#define __late_set_fixmap __set_fixmap
114#define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
115
116extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
117
118#include <asm-generic/fixmap.h>
119
120#endif /* !__ASSEMBLER__ */
121#endif /* _ASM_ARM64_FIXMAP_H */