xref: /linux/arch/arm64/include/asm/fixmap.h (revision 4949009eb8d40a441dcddcd96e101e77d31cf1b2)
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_64 version.
12  *
13  */
14 
15 #ifndef _ASM_ARM64_FIXMAP_H
16 #define _ASM_ARM64_FIXMAP_H
17 
18 #ifndef __ASSEMBLY__
19 #include <linux/kernel.h>
20 #include <asm/page.h>
21 
22 /*
23  * Here we define all the compile-time 'special' virtual
24  * addresses. The point is to have a constant address at
25  * compile time, but to set the physical address only
26  * in the boot process.
27  *
28  * These 'compile-time allocated' memory buffers are
29  * page-sized. Use set_fixmap(idx,phys) to associate
30  * physical memory with fixmap indices.
31  *
32  */
33 enum fixed_addresses {
34 	FIX_HOLE,
35 	FIX_EARLYCON_MEM_BASE,
36 	__end_of_permanent_fixed_addresses,
37 
38 	/*
39 	 * Temporary boot-time mappings, used by early_ioremap(),
40 	 * before ioremap() is functional.
41 	 */
42 #ifdef CONFIG_ARM64_64K_PAGES
43 #define NR_FIX_BTMAPS		4
44 #else
45 #define NR_FIX_BTMAPS		64
46 #endif
47 #define FIX_BTMAPS_SLOTS	7
48 #define TOTAL_FIX_BTMAPS	(NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
49 
50 	FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
51 	FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
52 	__end_of_fixed_addresses
53 };
54 
55 #define FIXADDR_SIZE	(__end_of_permanent_fixed_addresses << PAGE_SHIFT)
56 #define FIXADDR_START	(FIXADDR_TOP - FIXADDR_SIZE)
57 
58 #define FIXMAP_PAGE_IO     __pgprot(PROT_DEVICE_nGnRE)
59 
60 void __init early_fixmap_init(void);
61 
62 #define __early_set_fixmap __set_fixmap
63 
64 extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
65 
66 #include <asm-generic/fixmap.h>
67 
68 #endif /* !__ASSEMBLY__ */
69 #endif /* _ASM_ARM64_FIXMAP_H */
70