xref: /openbmc/linux/arch/x86/include/asm/setup.h (revision b5265c81)
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 
12 #ifdef __i386__
13 
14 #include <linux/pfn.h>
15 /*
16  * Reserved space for vmalloc and iomap - defined in asm/page.h
17  */
18 #define MAXMEM_PFN	PFN_DOWN(MAXMEM)
19 #define MAX_NONPAE_PFN	(1 << 20)
20 
21 #endif /* __i386__ */
22 
23 #define PARAM_SIZE 4096		/* sizeof(struct boot_params) */
24 
25 #define OLD_CL_MAGIC		0xA33F
26 #define OLD_CL_ADDRESS		0x020	/* Relative to real mode data */
27 #define NEW_CL_POINTER		0x228	/* Relative to real mode data */
28 
29 #ifndef __ASSEMBLY__
30 #include <asm/bootparam.h>
31 #include <asm/x86_init.h>
32 
33 extern u64 relocated_ramdisk;
34 
35 /* Interrupt control for vSMPowered x86_64 systems */
36 #ifdef CONFIG_X86_64
37 void vsmp_init(void);
38 #else
39 static inline void vsmp_init(void) { }
40 #endif
41 
42 void setup_bios_corruption_check(void);
43 void early_platform_quirks(void);
44 
45 extern unsigned long saved_video_mode;
46 
47 extern void reserve_standard_io_resources(void);
48 extern void i386_reserve_resources(void);
49 extern unsigned long __startup_64(unsigned long physaddr, struct boot_params *bp);
50 extern unsigned long __startup_secondary_64(void);
51 extern int early_make_pgtable(unsigned long address);
52 
53 #ifdef CONFIG_X86_INTEL_MID
54 extern void x86_intel_mid_early_setup(void);
55 #else
56 static inline void x86_intel_mid_early_setup(void) { }
57 #endif
58 
59 #ifdef CONFIG_X86_INTEL_CE
60 extern void x86_ce4100_early_setup(void);
61 #else
62 static inline void x86_ce4100_early_setup(void) { }
63 #endif
64 
65 #ifndef _SETUP
66 
67 #include <asm/espfix.h>
68 #include <linux/kernel.h>
69 
70 /*
71  * This is set up by the setup-routine at boot-time
72  */
73 extern struct boot_params boot_params;
74 extern char _text[];
75 
76 static inline bool kaslr_enabled(void)
77 {
78 	return IS_ENABLED(CONFIG_RANDOMIZE_MEMORY) &&
79 		!!(boot_params.hdr.loadflags & KASLR_FLAG);
80 }
81 
82 /*
83  * Apply no randomization if KASLR was disabled at boot or if KASAN
84  * is enabled. KASAN shadow mappings rely on regions being PGD aligned.
85  */
86 static inline bool kaslr_memory_enabled(void)
87 {
88 	return kaslr_enabled() && !IS_ENABLED(CONFIG_KASAN);
89 }
90 
91 static inline unsigned long kaslr_offset(void)
92 {
93 	return (unsigned long)&_text - __START_KERNEL;
94 }
95 
96 /*
97  * Do NOT EVER look at the BIOS memory size location.
98  * It does not work on many machines.
99  */
100 #define LOWMEMSIZE()	(0x9f000)
101 
102 /* exceedingly early brk-like allocator */
103 extern unsigned long _brk_end;
104 void *extend_brk(size_t size, size_t align);
105 
106 /*
107  * Reserve space in the brk section.  The name must be unique within
108  * the file, and somewhat descriptive.  The size is in bytes.  Must be
109  * used at file scope.
110  *
111  * (This uses a temp function to wrap the asm so we can pass it the
112  * size parameter; otherwise we wouldn't be able to.  We can't use a
113  * "section" attribute on a normal variable because it always ends up
114  * being @progbits, which ends up allocating space in the vmlinux
115  * executable.)
116  */
117 #define RESERVE_BRK(name,sz)						\
118 	static void __section(.discard.text) __used notrace		\
119 	__brk_reservation_fn_##name##__(void) {				\
120 		asm volatile (						\
121 			".pushsection .brk_reservation,\"aw\",@nobits;" \
122 			".brk." #name ":"				\
123 			" 1:.skip %c0;"					\
124 			" .size .brk." #name ", . - 1b;"		\
125 			" .popsection"					\
126 			: : "i" (sz));					\
127 	}
128 
129 /* Helper for reserving space for arrays of things */
130 #define RESERVE_BRK_ARRAY(type, name, entries)		\
131 	type *name;					\
132 	RESERVE_BRK(name, sizeof(type) * entries)
133 
134 extern void probe_roms(void);
135 #ifdef __i386__
136 
137 asmlinkage void __init i386_start_kernel(void);
138 
139 #else
140 asmlinkage void __init x86_64_start_kernel(char *real_mode);
141 asmlinkage void __init x86_64_start_reservations(char *real_mode_data);
142 
143 #endif /* __i386__ */
144 #endif /* _SETUP */
145 #else
146 #define RESERVE_BRK(name,sz)				\
147 	.pushsection .brk_reservation,"aw",@nobits;	\
148 .brk.name:						\
149 1:	.skip sz;					\
150 	.size .brk.name,.-1b;				\
151 	.popsection
152 #endif /* __ASSEMBLY__ */
153 #endif /* _ASM_X86_SETUP_H */
154