2 * fixmap.h: compile-time virtual memory allocation
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
8 * Copyright (C) 1998 Ingo Molnar
9 * Copyright (C) 2013 Mark Salter <msalter@redhat.com>
11 * Adapted from arch/x86 version.
15 #ifndef _ASM_ARM64_FIXMAP_H
16 #define _ASM_ARM64_FIXMAP_H
19 #include <linux/kernel.h>
20 #include <linux/sizes.h>
23 #include <asm/pgtable-prot.h>
26 * Here we define all the compile-time 'special' virtual
27 * addresses. The point is to have a constant address at
28 * compile time, but to set the physical address only
29 * in the boot process.
31 * These 'compile-time allocated' memory buffers are
32 * page-sized. Use set_fixmap(idx,phys) to associate
33 * physical memory with fixmap indices.
36 enum fixed_addresses {
40 * Reserve a virtual window for the FDT that is 2 MB larger than the
41 * maximum supported size, and put it at the top of the fixmap region.
42 * The additional space ensures that any FDT that does not exceed
43 * MAX_FDT_SIZE can be mapped regardless of whether it crosses any
44 * 2 MB alignment boundaries.
46 * Keep this at the top so it remains 2 MB aligned.
48 #define FIX_FDT_SIZE (MAX_FDT_SIZE + SZ_2M)
50 FIX_FDT = FIX_FDT_END + FIX_FDT_SIZE / PAGE_SIZE - 1,
52 FIX_EARLYCON_MEM_BASE,
55 #ifdef CONFIG_UNMAP_KERNEL_AT_EL0
58 #define TRAMP_VALIAS (__fix_to_virt(FIX_ENTRY_TRAMP_TEXT))
59 #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */
60 __end_of_permanent_fixed_addresses,
63 * Temporary boot-time mappings, used by early_ioremap(),
64 * before ioremap() is functional.
66 #define NR_FIX_BTMAPS (SZ_256K / PAGE_SIZE)
67 #define FIX_BTMAPS_SLOTS 7
68 #define TOTAL_FIX_BTMAPS (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
70 FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
71 FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
74 * Used for kernel page table creation, so unmapped memory may be used
82 __end_of_fixed_addresses
85 #define FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT)
86 #define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE)
88 #define FIXMAP_PAGE_IO __pgprot(PROT_DEVICE_nGnRE)
90 void __init early_fixmap_init(void);
92 #define __early_set_fixmap __set_fixmap
94 #define __late_set_fixmap __set_fixmap
95 #define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR)
97 extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
99 #include <asm-generic/fixmap.h>
101 #endif /* !__ASSEMBLY__ */
102 #endif /* _ASM_ARM64_FIXMAP_H */