xref: /linux/arch/x86/include/asm/asm.h (revision 2f0a7504530c24f55daec7d2364d933bb1a1fa68)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_X86_ASM_H
3 #define _ASM_X86_ASM_H
4 
5 #ifdef __ASSEMBLER__
6 # define __ASM_FORM(x, ...)		x,## __VA_ARGS__
7 # define __ASM_FORM_RAW(x, ...)		x,## __VA_ARGS__
8 # define __ASM_FORM_COMMA(x, ...)	x,## __VA_ARGS__,
9 # define __ASM_REGPFX			%
10 #else
11 #include <linux/stringify.h>
12 # define __ASM_FORM(x, ...)		" " __stringify(x,##__VA_ARGS__) " "
13 # define __ASM_FORM_RAW(x, ...)		    __stringify(x,##__VA_ARGS__)
14 # define __ASM_FORM_COMMA(x, ...)	" " __stringify(x,##__VA_ARGS__) ","
15 # define __ASM_REGPFX			%%
16 #endif
17 
18 #define _ASM_BYTES(x, ...)	__ASM_FORM(.byte x,##__VA_ARGS__ ;)
19 
20 #ifndef __x86_64__
21 /* 32 bit */
22 # define __ASM_SEL(a,b)		__ASM_FORM(a)
23 # define __ASM_SEL_RAW(a,b)	__ASM_FORM_RAW(a)
24 #else
25 /* 64 bit */
26 # define __ASM_SEL(a,b)		__ASM_FORM(b)
27 # define __ASM_SEL_RAW(a,b)	__ASM_FORM_RAW(b)
28 #endif
29 
30 #define __ASM_SIZE(inst, ...)	__ASM_SEL(inst##l##__VA_ARGS__, \
31 					  inst##q##__VA_ARGS__)
32 #define __ASM_REG(reg)         __ASM_SEL_RAW(e##reg, r##reg)
33 
34 #define _ASM_PTR	__ASM_SEL(.long, .quad)
35 #define _ASM_ALIGN	__ASM_SEL(.balign 4, .balign 8)
36 
37 #define _ASM_MOV	__ASM_SIZE(mov)
38 #define _ASM_INC	__ASM_SIZE(inc)
39 #define _ASM_DEC	__ASM_SIZE(dec)
40 #define _ASM_ADD	__ASM_SIZE(add)
41 #define _ASM_SUB	__ASM_SIZE(sub)
42 #define _ASM_XADD	__ASM_SIZE(xadd)
43 #define _ASM_MUL	__ASM_SIZE(mul)
44 
45 #define _ASM_AX		__ASM_REG(ax)
46 #define _ASM_BX		__ASM_REG(bx)
47 #define _ASM_CX		__ASM_REG(cx)
48 #define _ASM_DX		__ASM_REG(dx)
49 #define _ASM_SP		__ASM_REG(sp)
50 #define _ASM_BP		__ASM_REG(bp)
51 #define _ASM_SI		__ASM_REG(si)
52 #define _ASM_DI		__ASM_REG(di)
53 
54 /* Adds a (%rip) suffix on 64 bits only; for immediate memory references */
55 #define _ASM_RIP(x)	__ASM_SEL_RAW(x, x (__ASM_REGPFX rip))
56 
57 #ifndef __x86_64__
58 /* 32 bit */
59 
60 #define _ASM_ARG1	_ASM_AX
61 #define _ASM_ARG2	_ASM_DX
62 #define _ASM_ARG3	_ASM_CX
63 
64 #define _ASM_ARG1L	eax
65 #define _ASM_ARG2L	edx
66 #define _ASM_ARG3L	ecx
67 
68 #define _ASM_ARG1W	ax
69 #define _ASM_ARG2W	dx
70 #define _ASM_ARG3W	cx
71 
72 #define _ASM_ARG1B	al
73 #define _ASM_ARG2B	dl
74 #define _ASM_ARG3B	cl
75 
76 #else
77 /* 64 bit */
78 
79 #define _ASM_ARG1	_ASM_DI
80 #define _ASM_ARG2	_ASM_SI
81 #define _ASM_ARG3	_ASM_DX
82 #define _ASM_ARG4	_ASM_CX
83 #define _ASM_ARG5	r8
84 #define _ASM_ARG6	r9
85 
86 #define _ASM_ARG1Q	rdi
87 #define _ASM_ARG2Q	rsi
88 #define _ASM_ARG3Q	rdx
89 #define _ASM_ARG4Q	rcx
90 #define _ASM_ARG5Q	r8
91 #define _ASM_ARG6Q	r9
92 
93 #define _ASM_ARG1L	edi
94 #define _ASM_ARG2L	esi
95 #define _ASM_ARG3L	edx
96 #define _ASM_ARG4L	ecx
97 #define _ASM_ARG5L	r8d
98 #define _ASM_ARG6L	r9d
99 
100 #define _ASM_ARG1W	di
101 #define _ASM_ARG2W	si
102 #define _ASM_ARG3W	dx
103 #define _ASM_ARG4W	cx
104 #define _ASM_ARG5W	r8w
105 #define _ASM_ARG6W	r9w
106 
107 #define _ASM_ARG1B	dil
108 #define _ASM_ARG2B	sil
109 #define _ASM_ARG3B	dl
110 #define _ASM_ARG4B	cl
111 #define _ASM_ARG5B	r8b
112 #define _ASM_ARG6B	r9b
113 
114 #endif
115 
116 #ifndef __ASSEMBLER__
rip_rel_ptr(void * p)117 static __always_inline __pure void *rip_rel_ptr(void *p)
118 {
119 	asm("leaq %c1(%%rip), %0" : "=r"(p) : "i"(p));
120 
121 	return p;
122 }
123 #endif
124 
125 #ifdef __KERNEL__
126 
127 # include <asm/extable_fixup_types.h>
128 
129 /* Exception table entry */
130 #ifdef __ASSEMBLER__
131 
132 # define _ASM_EXTABLE_TYPE(from, to, type)			\
133 	.pushsection "__ex_table","a" ;				\
134 	.balign 4 ;						\
135 	.long (from) - . ;					\
136 	.long (to) - . ;					\
137 	.long type ;						\
138 	.popsection
139 
140 # ifdef CONFIG_KPROBES
141 #  define _ASM_NOKPROBE(entry)					\
142 	.pushsection "_kprobe_blacklist","aw" ;			\
143 	_ASM_ALIGN ;						\
144 	_ASM_PTR (entry);					\
145 	.popsection
146 # else
147 #  define _ASM_NOKPROBE(entry)
148 # endif
149 
150 #else /* ! __ASSEMBLER__ */
151 
152 # define DEFINE_EXTABLE_TYPE_REG \
153 	".macro extable_type_reg type:req reg:req\n"						\
154 	".set .Lfound, 0\n"									\
155 	".set .Lregnr, 0\n"									\
156 	".irp rs,rax,rcx,rdx,rbx,rsp,rbp,rsi,rdi,r8,r9,r10,r11,r12,r13,r14,r15\n"		\
157 	".ifc \\reg, %%\\rs\n"									\
158 	".set .Lfound, .Lfound+1\n"								\
159 	".long \\type + (.Lregnr << 8)\n"							\
160 	".endif\n"										\
161 	".set .Lregnr, .Lregnr+1\n"								\
162 	".endr\n"										\
163 	".set .Lregnr, 0\n"									\
164 	".irp rs,eax,ecx,edx,ebx,esp,ebp,esi,edi,r8d,r9d,r10d,r11d,r12d,r13d,r14d,r15d\n"	\
165 	".ifc \\reg, %%\\rs\n"									\
166 	".set .Lfound, .Lfound+1\n"								\
167 	".long \\type + (.Lregnr << 8)\n"							\
168 	".endif\n"										\
169 	".set .Lregnr, .Lregnr+1\n"								\
170 	".endr\n"										\
171 	".if (.Lfound != 1)\n"									\
172 	".error \"extable_type_reg: bad register argument\"\n"					\
173 	".endif\n"										\
174 	".endm\n"
175 
176 # define UNDEFINE_EXTABLE_TYPE_REG \
177 	".purgem extable_type_reg\n"
178 
179 # define _ASM_EXTABLE_TYPE(from, to, type)			\
180 	" .pushsection \"__ex_table\",\"a\"\n"			\
181 	" .balign 4\n"						\
182 	" .long (" #from ") - .\n"				\
183 	" .long (" #to ") - .\n"				\
184 	" .long " __stringify(type) " \n"			\
185 	" .popsection\n"
186 
187 # define _ASM_EXTABLE_TYPE_REG(from, to, type, reg)				\
188 	" .pushsection \"__ex_table\",\"a\"\n"					\
189 	" .balign 4\n"								\
190 	" .long (" #from ") - .\n"						\
191 	" .long (" #to ") - .\n"						\
192 	DEFINE_EXTABLE_TYPE_REG							\
193 	"extable_type_reg reg=" __stringify(reg) ", type=" __stringify(type) " \n"\
194 	UNDEFINE_EXTABLE_TYPE_REG						\
195 	" .popsection\n"
196 
197 /* For C file, we already have NOKPROBE_SYMBOL macro */
198 
199 /* Insert a comma if args are non-empty */
200 #define COMMA(x...)		__COMMA(x)
201 #define __COMMA(...)		, ##__VA_ARGS__
202 
203 /*
204  * Combine multiple asm inline constraint args into a single arg for passing to
205  * another macro.
206  */
207 #define ASM_OUTPUT(x...)	x
208 #define ASM_INPUT(x...)		x
209 
210 /*
211  * This output constraint should be used for any inline asm which has a "call"
212  * instruction.  Otherwise the asm may be inserted before the frame pointer
213  * gets set up by the containing function.  If you forget to do this, objtool
214  * may print a "call without frame pointer save/setup" warning.
215  */
216 register unsigned long current_stack_pointer asm(_ASM_SP);
217 #define ASM_CALL_CONSTRAINT "+r" (current_stack_pointer)
218 #endif /* __ASSEMBLER__ */
219 
220 #define _ASM_EXTABLE(from, to)					\
221 	_ASM_EXTABLE_TYPE(from, to, EX_TYPE_DEFAULT)
222 
223 #define _ASM_EXTABLE_UA(from, to)				\
224 	_ASM_EXTABLE_TYPE(from, to, EX_TYPE_UACCESS)
225 
226 #define _ASM_EXTABLE_FAULT(from, to)				\
227 	_ASM_EXTABLE_TYPE(from, to, EX_TYPE_FAULT)
228 
229 /*
230  * Both i386 and x86_64 returns 64-bit values in edx:eax for certain
231  * instructions, but GCC's "A" constraint has different meanings.
232  * For i386, "A" means exactly edx:eax, while for x86_64 it
233  * means rax *or* rdx.
234  *
235  * These helpers wrapping these semantic differences save one instruction
236  * clearing the high half of 'low':
237  */
238 #ifdef CONFIG_X86_64
239 # define EAX_EDX_DECLARE_ARGS(val, low, high)	unsigned long low, high
240 # define EAX_EDX_VAL(val, low, high)		((low) | (high) << 32)
241 # define EAX_EDX_RET(val, low, high)		"=a" (low), "=d" (high)
242 #else
243 # define EAX_EDX_DECLARE_ARGS(val, low, high)	u64 val
244 # define EAX_EDX_VAL(val, low, high)		(val)
245 # define EAX_EDX_RET(val, low, high)		"=A" (val)
246 #endif
247 
248 #endif /* __KERNEL__ */
249 #endif /* _ASM_X86_ASM_H */
250