xref: /linux/arch/arm64/include/asm/fixmap.h (revision 43db1111073049220381944af4a3b8a5400eda71)
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 __ASSEMBLY__
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  */
36 enum 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 
109 void __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 
116 extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot);
117 
118 #include <asm-generic/fixmap.h>
119 
120 #endif /* !__ASSEMBLY__ */
121 #endif /* _ASM_ARM64_FIXMAP_H */
122