xref: /linux/arch/x86/include/asm/setup.h (revision c4101e55974cc7d835fbd2d8e01553a3f61e9e75)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_SETUP_H
3 #define _ASM_X86_SETUP_H
4 
5 #include <uapi/asm/setup.h>
6 
7 #define COMMAND_LINE_SIZE 2048
8 
9 #include <linux/linkage.h>
10 #include <asm/page_types.h>
11 #include <asm/ibt.h>
12 
13 #ifdef __i386__
14 
15 #include <linux/pfn.h>
16 /*
17  * Reserved space for vmalloc and iomap - defined in asm/page.h
18  */
19 #define MAXMEM_PFN	PFN_DOWN(MAXMEM)
20 #define MAX_NONPAE_PFN	(1 << 20)
21 
22 #endif /* __i386__ */
23 
24 #define PARAM_SIZE 4096		/* sizeof(struct boot_params) */
25 
26 #define OLD_CL_MAGIC		0xA33F
27 #define OLD_CL_ADDRESS		0x020	/* Relative to real mode data */
28 #define NEW_CL_POINTER		0x228	/* Relative to real mode data */
29 
30 #ifndef __ASSEMBLY__
31 #include <asm/bootparam.h>
32 #include <asm/x86_init.h>
33 
34 /* Interrupt control for vSMPowered x86_64 systems */
35 #ifdef CONFIG_X86_64
36 void vsmp_init(void);
37 #else
38 static inline void vsmp_init(void) { }
39 #endif
40 
41 struct pt_regs;
42 
43 void setup_bios_corruption_check(void);
44 void early_platform_quirks(void);
45 
46 extern unsigned long saved_video_mode;
47 
48 extern void reserve_standard_io_resources(void);
49 extern void i386_reserve_resources(void);
50 extern unsigned long __startup_64(unsigned long physaddr, struct boot_params *bp);
51 extern void startup_64_setup_env(unsigned long physbase);
52 extern void early_setup_idt(void);
53 extern void __init do_early_exception(struct pt_regs *regs, int trapnr);
54 
55 #ifdef CONFIG_X86_INTEL_MID
56 extern void x86_intel_mid_early_setup(void);
57 #else
58 static inline void x86_intel_mid_early_setup(void) { }
59 #endif
60 
61 #ifdef CONFIG_X86_INTEL_CE
62 extern void x86_ce4100_early_setup(void);
63 #else
64 static inline void x86_ce4100_early_setup(void) { }
65 #endif
66 
67 #ifndef _SETUP
68 
69 #include <asm/espfix.h>
70 #include <linux/kernel.h>
71 
72 /*
73  * This is set up by the setup-routine at boot-time
74  */
75 extern struct boot_params boot_params;
76 extern char _text[];
77 
78 static inline bool kaslr_enabled(void)
79 {
80 	return IS_ENABLED(CONFIG_RANDOMIZE_MEMORY) &&
81 		!!(boot_params.hdr.loadflags & KASLR_FLAG);
82 }
83 
84 /*
85  * Apply no randomization if KASLR was disabled at boot or if KASAN
86  * is enabled. KASAN shadow mappings rely on regions being PGD aligned.
87  */
88 static inline bool kaslr_memory_enabled(void)
89 {
90 	return kaslr_enabled() && !IS_ENABLED(CONFIG_KASAN);
91 }
92 
93 static inline unsigned long kaslr_offset(void)
94 {
95 	return (unsigned long)&_text - __START_KERNEL;
96 }
97 
98 /*
99  * Do NOT EVER look at the BIOS memory size location.
100  * It does not work on many machines.
101  */
102 #define LOWMEMSIZE()	(0x9f000)
103 
104 /* exceedingly early brk-like allocator */
105 extern unsigned long _brk_end;
106 void *extend_brk(size_t size, size_t align);
107 
108 /*
109  * Reserve space in the .brk section, which is a block of memory from which the
110  * caller is allowed to allocate very early (before even memblock is available)
111  * by calling extend_brk().  All allocated memory will be eventually converted
112  * to memblock.  Any leftover unallocated memory will be freed.
113  *
114  * The size is in bytes.
115  */
116 #define RESERVE_BRK(name, size)					\
117 	__section(".bss..brk") __aligned(1) __used	\
118 	static char __brk_##name[size]
119 
120 extern void probe_roms(void);
121 
122 void clear_bss(void);
123 
124 #ifdef __i386__
125 
126 asmlinkage void __init __noreturn i386_start_kernel(void);
127 void __init mk_early_pgtbl_32(void);
128 
129 #else
130 asmlinkage void __init __noreturn x86_64_start_kernel(char *real_mode);
131 asmlinkage void __init __noreturn x86_64_start_reservations(char *real_mode_data);
132 
133 #endif /* __i386__ */
134 #endif /* _SETUP */
135 
136 #else  /* __ASSEMBLY */
137 
138 .macro __RESERVE_BRK name, size
139 	.pushsection .bss..brk, "aw"
140 SYM_DATA_START(__brk_\name)
141 	.skip \size
142 SYM_DATA_END(__brk_\name)
143 	.popsection
144 .endm
145 
146 #define RESERVE_BRK(name, size) __RESERVE_BRK name, size
147 
148 #endif /* __ASSEMBLY__ */
149 
150 #endif /* _ASM_X86_SETUP_H */
151