xref: /linux/arch/x86/include/asm/asm.h (revision 7fc2cd2e4b398c57c9cf961cfea05eadbf34c05c)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_ASM_H
3 #define _ASM_X86_ASM_H
4 
5 #include <linux/annotate.h>
6 
7 #ifdef __ASSEMBLER__
8 # define __ASM_FORM(x, ...)		x,## __VA_ARGS__
9 # define __ASM_FORM_RAW(x, ...)		x,## __VA_ARGS__
10 # define __ASM_FORM_COMMA(x, ...)	x,## __VA_ARGS__,
11 # define __ASM_REGPFX			%
12 #else
13 #include <linux/stringify.h>
14 # define __ASM_FORM(x, ...)		" " __stringify(x,##__VA_ARGS__) " "
15 # define __ASM_FORM_RAW(x, ...)		    __stringify(x,##__VA_ARGS__)
16 # define __ASM_FORM_COMMA(x, ...)	" " __stringify(x,##__VA_ARGS__) ","
17 # define __ASM_REGPFX			%%
18 #endif
19 
20 #define _ASM_BYTES(x, ...)	__ASM_FORM(.byte x,##__VA_ARGS__ ;)
21 
22 #ifndef __x86_64__
23 /* 32 bit */
24 # define __ASM_SEL(a,b)		__ASM_FORM(a)
25 # define __ASM_SEL_RAW(a,b)	__ASM_FORM_RAW(a)
26 #else
27 /* 64 bit */
28 # define __ASM_SEL(a,b)		__ASM_FORM(b)
29 # define __ASM_SEL_RAW(a,b)	__ASM_FORM_RAW(b)
30 #endif
31 
32 #define __ASM_SIZE(inst, ...)	__ASM_SEL(inst##l##__VA_ARGS__, \
33 					  inst##q##__VA_ARGS__)
34 #define __ASM_REG(reg)         __ASM_SEL_RAW(e##reg, r##reg)
35 
36 #define _ASM_PTR	__ASM_SEL(.long, .quad)
37 #define _ASM_ALIGN	__ASM_SEL(.balign 4, .balign 8)
38 
39 #define _ASM_MOV	__ASM_SIZE(mov)
40 #define _ASM_INC	__ASM_SIZE(inc)
41 #define _ASM_DEC	__ASM_SIZE(dec)
42 #define _ASM_ADD	__ASM_SIZE(add)
43 #define _ASM_SUB	__ASM_SIZE(sub)
44 #define _ASM_XADD	__ASM_SIZE(xadd)
45 #define _ASM_MUL	__ASM_SIZE(mul)
46 
47 #define _ASM_AX		__ASM_REG(ax)
48 #define _ASM_BX		__ASM_REG(bx)
49 #define _ASM_CX		__ASM_REG(cx)
50 #define _ASM_DX		__ASM_REG(dx)
51 #define _ASM_SP		__ASM_REG(sp)
52 #define _ASM_BP		__ASM_REG(bp)
53 #define _ASM_SI		__ASM_REG(si)
54 #define _ASM_DI		__ASM_REG(di)
55 
56 /* Adds a (%rip) suffix on 64 bits only; for immediate memory references */
57 #define _ASM_RIP(x)	__ASM_SEL_RAW(x, x (__ASM_REGPFX rip))
58 
59 #ifndef __x86_64__
60 /* 32 bit */
61 
62 #define _ASM_ARG1	_ASM_AX
63 #define _ASM_ARG2	_ASM_DX
64 #define _ASM_ARG3	_ASM_CX
65 
66 #define _ASM_ARG1L	eax
67 #define _ASM_ARG2L	edx
68 #define _ASM_ARG3L	ecx
69 
70 #define _ASM_ARG1W	ax
71 #define _ASM_ARG2W	dx
72 #define _ASM_ARG3W	cx
73 
74 #define _ASM_ARG1B	al
75 #define _ASM_ARG2B	dl
76 #define _ASM_ARG3B	cl
77 
78 #else
79 /* 64 bit */
80 
81 #define _ASM_ARG1	_ASM_DI
82 #define _ASM_ARG2	_ASM_SI
83 #define _ASM_ARG3	_ASM_DX
84 #define _ASM_ARG4	_ASM_CX
85 #define _ASM_ARG5	r8
86 #define _ASM_ARG6	r9
87 
88 #define _ASM_ARG1Q	rdi
89 #define _ASM_ARG2Q	rsi
90 #define _ASM_ARG3Q	rdx
91 #define _ASM_ARG4Q	rcx
92 #define _ASM_ARG5Q	r8
93 #define _ASM_ARG6Q	r9
94 
95 #define _ASM_ARG1L	edi
96 #define _ASM_ARG2L	esi
97 #define _ASM_ARG3L	edx
98 #define _ASM_ARG4L	ecx
99 #define _ASM_ARG5L	r8d
100 #define _ASM_ARG6L	r9d
101 
102 #define _ASM_ARG1W	di
103 #define _ASM_ARG2W	si
104 #define _ASM_ARG3W	dx
105 #define _ASM_ARG4W	cx
106 #define _ASM_ARG5W	r8w
107 #define _ASM_ARG6W	r9w
108 
109 #define _ASM_ARG1B	dil
110 #define _ASM_ARG2B	sil
111 #define _ASM_ARG3B	dl
112 #define _ASM_ARG4B	cl
113 #define _ASM_ARG5B	r8b
114 #define _ASM_ARG6B	r9b
115 
116 #endif
117 
118 #ifndef __ASSEMBLER__
119 static __always_inline __pure void *rip_rel_ptr(void *p)
120 {
121 	asm("leaq %c1(%%rip), %0" : "=r"(p) : "i"(p));
122 
123 	return p;
124 }
125 #endif
126 
127 #ifdef __KERNEL__
128 
129 # include <asm/extable_fixup_types.h>
130 
131 /* Exception table entry */
132 #ifdef __ASSEMBLER__
133 
134 # define _ASM_EXTABLE_TYPE(from, to, type)			\
135 	.pushsection "__ex_table","a" ;				\
136 	.balign 4 ;						\
137 	ANNOTATE_DATA_SPECIAL ;					\
138 	.long (from) - . ;					\
139 	.long (to) - . ;					\
140 	.long type ;						\
141 	.popsection
142 
143 # ifdef CONFIG_KPROBES
144 #  define _ASM_NOKPROBE(entry)					\
145 	.pushsection "_kprobe_blacklist","aw" ;			\
146 	_ASM_ALIGN ;						\
147 	_ASM_PTR (entry);					\
148 	.popsection
149 # else
150 #  define _ASM_NOKPROBE(entry)
151 # endif
152 
153 #else /* ! __ASSEMBLER__ */
154 
155 # define DEFINE_EXTABLE_TYPE_REG \
156 	".macro extable_type_reg type:req reg:req\n"						\
157 	".set .Lfound, 0\n"									\
158 	".set .Lregnr, 0\n"									\
159 	".irp rs,rax,rcx,rdx,rbx,rsp,rbp,rsi,rdi,r8,r9,r10,r11,r12,r13,r14,r15\n"		\
160 	".ifc \\reg, %%\\rs\n"									\
161 	".set .Lfound, .Lfound+1\n"								\
162 	".long \\type + (.Lregnr << 8)\n"							\
163 	".endif\n"										\
164 	".set .Lregnr, .Lregnr+1\n"								\
165 	".endr\n"										\
166 	".set .Lregnr, 0\n"									\
167 	".irp rs,eax,ecx,edx,ebx,esp,ebp,esi,edi,r8d,r9d,r10d,r11d,r12d,r13d,r14d,r15d\n"	\
168 	".ifc \\reg, %%\\rs\n"									\
169 	".set .Lfound, .Lfound+1\n"								\
170 	".long \\type + (.Lregnr << 8)\n"							\
171 	".endif\n"										\
172 	".set .Lregnr, .Lregnr+1\n"								\
173 	".endr\n"										\
174 	".if (.Lfound != 1)\n"									\
175 	".error \"extable_type_reg: bad register argument\"\n"					\
176 	".endif\n"										\
177 	".endm\n"
178 
179 # define UNDEFINE_EXTABLE_TYPE_REG \
180 	".purgem extable_type_reg\n"
181 
182 # define _ASM_EXTABLE_TYPE(from, to, type)			\
183 	" .pushsection \"__ex_table\",\"a\"\n"			\
184 	" .balign 4\n"						\
185 	ANNOTATE_DATA_SPECIAL					\
186 	" .long (" #from ") - .\n"				\
187 	" .long (" #to ") - .\n"				\
188 	" .long " __stringify(type) " \n"			\
189 	" .popsection\n"
190 
191 # define _ASM_EXTABLE_TYPE_REG(from, to, type, reg)				\
192 	" .pushsection \"__ex_table\",\"a\"\n"					\
193 	" .balign 4\n"								\
194 	ANNOTATE_DATA_SPECIAL							\
195 	" .long (" #from ") - .\n"						\
196 	" .long (" #to ") - .\n"						\
197 	DEFINE_EXTABLE_TYPE_REG							\
198 	"extable_type_reg reg=" __stringify(reg) ", type=" __stringify(type) " \n"\
199 	UNDEFINE_EXTABLE_TYPE_REG						\
200 	" .popsection\n"
201 
202 /* For C file, we already have NOKPROBE_SYMBOL macro */
203 
204 /* Insert a comma if args are non-empty */
205 #define COMMA(x...)		__COMMA(x)
206 #define __COMMA(...)		, ##__VA_ARGS__
207 
208 /*
209  * Combine multiple asm inline constraint args into a single arg for passing to
210  * another macro.
211  */
212 #define ASM_OUTPUT(x...)	x
213 #define ASM_INPUT(x...)		x
214 
215 /*
216  * This output constraint should be used for any inline asm which has a "call"
217  * instruction.  Otherwise the asm may be inserted before the frame pointer
218  * gets set up by the containing function.  If you forget to do this, objtool
219  * may print a "call without frame pointer save/setup" warning.
220  */
221 register unsigned long current_stack_pointer asm(_ASM_SP);
222 #define ASM_CALL_CONSTRAINT "+r" (current_stack_pointer)
223 #endif /* __ASSEMBLER__ */
224 
225 #define _ASM_EXTABLE(from, to)					\
226 	_ASM_EXTABLE_TYPE(from, to, EX_TYPE_DEFAULT)
227 
228 #define _ASM_EXTABLE_UA(from, to)				\
229 	_ASM_EXTABLE_TYPE(from, to, EX_TYPE_UACCESS)
230 
231 #define _ASM_EXTABLE_FAULT(from, to)				\
232 	_ASM_EXTABLE_TYPE(from, to, EX_TYPE_FAULT)
233 
234 /*
235  * Both i386 and x86_64 returns 64-bit values in edx:eax for certain
236  * instructions, but GCC's "A" constraint has different meanings.
237  * For i386, "A" means exactly edx:eax, while for x86_64 it
238  * means rax *or* rdx.
239  *
240  * These helpers wrapping these semantic differences save one instruction
241  * clearing the high half of 'low':
242  */
243 #ifdef CONFIG_X86_64
244 # define EAX_EDX_DECLARE_ARGS(val, low, high)	unsigned long low, high
245 # define EAX_EDX_VAL(val, low, high)		((low) | (high) << 32)
246 # define EAX_EDX_RET(val, low, high)		"=a" (low), "=d" (high)
247 #else
248 # define EAX_EDX_DECLARE_ARGS(val, low, high)	u64 val
249 # define EAX_EDX_VAL(val, low, high)		(val)
250 # define EAX_EDX_RET(val, low, high)		"=A" (val)
251 #endif
252 
253 #endif /* __KERNEL__ */
254 #endif /* _ASM_X86_ASM_H */
255