xref: /netbsd-src/sys/arch/arm/include/asm.h (revision 04a00918c8a6815c792bde221c14d63cf5d3234a)
1 /*	$NetBSD: asm.h,v 1.35 2024/06/09 22:35:47 riastradh Exp $	*/
2 
3 /*-
4  * Copyright (c) 2014 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Matt Thomas of 3am Software Foundry.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Copyright (c) 1990 The Regents of the University of California.
34  * All rights reserved.
35  *
36  * This code is derived from software contributed to Berkeley by
37  * William Jolitz.
38  *
39  * Redistribution and use in source and binary forms, with or without
40  * modification, are permitted provided that the following conditions
41  * are met:
42  * 1. Redistributions of source code must retain the above copyright
43  *    notice, this list of conditions and the following disclaimer.
44  * 2. Redistributions in binary form must reproduce the above copyright
45  *    notice, this list of conditions and the following disclaimer in the
46  *    documentation and/or other materials provided with the distribution.
47  * 3. Neither the name of the University nor the names of its contributors
48  *    may be used to endorse or promote products derived from this software
49  *    without specific prior written permission.
50  *
51  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
52  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
53  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
54  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
55  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
56  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
57  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
58  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
59  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
60  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
61  * SUCH DAMAGE.
62  *
63  *	from: @(#)asm.h	5.5 (Berkeley) 5/7/91
64  */
65 
66 #ifndef _ARM_ASM_H_
67 #define _ARM_ASM_H_
68 
69 #include <arm/cdefs.h>
70 #if defined(_KERNEL_OPT)
71 #include "opt_cpuoptions.h"
72 #endif
73 
74 #ifdef __thumb__
75 #define THUMB_INSN(n)	n
76 #else
77 #define THUMB_INSN(n)
78 #endif
79 
80 #define	__BIT(n)	(1 << (n))
81 #define __BITS(hi,lo)	((~((~0)<<((hi)+1)))&((~0)<<(lo)))
82 
83 #define __LOWEST_SET_BIT(__mask) ((((__mask) - 1) & (__mask)) ^ (__mask))
84 #define __SHIFTOUT(__x, __mask) (((__x) & (__mask)) / __LOWEST_SET_BIT(__mask))
85 #define __SHIFTIN(__x, __mask) ((__x) * __LOWEST_SET_BIT(__mask))
86 
87 #define _C_LABEL(x)	x
88 #define	_ASM_LABEL(x)	x
89 
90 #ifdef __STDC__
91 # define __CONCAT(x,y)	x ## y
92 # define __STRING(x)	#x
93 #else
94 # define __CONCAT(x,y)	x/**/y
95 # define __STRING(x)	"x"
96 #endif
97 
98 #ifndef _ALIGN_TEXT
99 # define _ALIGN_TEXT .align 2
100 #endif
101 
102 #ifndef _TEXT_SECTION
103 #define _TEXT_SECTION	.text
104 #endif
105 
106 #ifdef __arm__
107 
108 	.syntax		unified
109 
110 /*
111  * gas/arm uses @ as a single comment character and thus cannot be used here
112  * Instead it recognised the # instead of an @ symbols in .type directives
113  * We define a couple of macros so that assembly code will not be dependent
114  * on one or the other.
115  */
116 #define _ASM_TYPE_FUNCTION	%function
117 #define _ASM_TYPE_OBJECT	%object
118 #define _THUMB_ENTRY(x) \
119 	_TEXT_SECTION; _ALIGN_TEXT; .globl x; .type x,_ASM_TYPE_FUNCTION; \
120 	.thumb_func; .code 16; x:
121 #define _ARM_ENTRY(x) \
122 	_TEXT_SECTION; _ALIGN_TEXT; .globl x; .type x,_ASM_TYPE_FUNCTION; \
123 	.code 32; x:
124 #ifdef __thumb__
125 #define	_ENTRY(x)	_THUMB_ENTRY(x)
126 #else
127 #define	_ENTRY(x)	_ARM_ENTRY(x)
128 #endif
129 #define	_END(x)		.size x,.-x
130 
131 #ifdef GPROF
132 # define _PROF_PROLOGUE	\
133 	mov ip, lr; bl __mcount
134 #else
135 # define _PROF_PROLOGUE
136 #endif
137 #endif
138 
139 #ifdef __aarch64__
140 #define _ASM_TYPE_FUNCTION	@function
141 #define _ASM_TYPE_OBJECT	@object
142 #define _ENTRY(x) \
143 	_TEXT_SECTION; _ALIGN_TEXT; .globl x; .type x,_ASM_TYPE_FUNCTION; x:
144 #define	_END(x)		.size x,.-x
145 
146 #ifdef GPROF
147 # define _PROF_PROLOGUE	\
148 	stp	x29, x30, [sp, #-16]!;	\
149 	mov	fp, sp;			\
150 	bl	__mcount; 		\
151 	ldp	x29, x30, [sp], #16;
152 #else
153 # define _PROF_PROLOGUE
154 #endif
155 
156 #ifdef __PIC__
157 #define GOTREF(x)		:got:x
158 #define GOTLO12(x)		:got_lo12:x
159 #else
160 #define GOTREF(x)		x
161 #define GOTLO12(x)		:lo12:x
162 #endif
163 #endif
164 
165 #ifdef ARMV85_BTI
166 #define	_BTI_PROLOGUE \
167 	.byte	0x5F, 0x24, 0x03, 0xD5	/* the "bti c" instruction */
168 #else
169 #define	_BTI_PROLOGUE		/* nothing */
170 #endif
171 
172 #define	ENTRY(y)		_ENTRY(_C_LABEL(y)); _BTI_PROLOGUE ; _PROF_PROLOGUE
173 #define	ENTRY_NP(y)		_ENTRY(_C_LABEL(y)); _BTI_PROLOGUE
174 #define	ENTRY_NBTI(y)		_ENTRY(_C_LABEL(y))
175 #define	END(y)			_END(_C_LABEL(y))
176 #define	ARM_ENTRY(y)		_ARM_ENTRY(_C_LABEL(y)); _PROF_PROLOGUE
177 #define	ARM_ENTRY_NP(y)		_ARM_ENTRY(_C_LABEL(y))
178 #define	THUMB_ENTRY(y)		_THUMB_ENTRY(_C_LABEL(y)); _PROF_PROLOGUE
179 #define	THUMB_ENTRY_NP(y)	_THUMB_ENTRY(_C_LABEL(y))
180 #define	ASENTRY(y)		_ENTRY(_ASM_LABEL(y)); _PROF_PROLOGUE
181 #define	ASENTRY_NP(y)		_ENTRY(_ASM_LABEL(y))
182 #define	ASEND(y)		_END(_ASM_LABEL(y))
183 #define	ARM_ASENTRY(y)		_ARM_ENTRY(_ASM_LABEL(y)); _PROF_PROLOGUE
184 #define	ARM_ASENTRY_NP(y)	_ARM_ENTRY(_ASM_LABEL(y))
185 #define	THUMB_ASENTRY(y)	_THUMB_ENTRY(_ASM_LABEL(y)); _PROF_PROLOGUE
186 #define	THUMB_ASENTRY_NP(y)	_THUMB_ENTRY(_ASM_LABEL(y))
187 
188 #define	ASMSTR		.asciz
189 
190 #ifdef __PIC__
191 #define	REL_SYM(a, b)	((a) - (b))
192 #define	PLT_SYM(x)	x
193 #define	GOT_SYM(x)	PIC_SYM(x, GOT)
194 #define	GOT_GET(x,got,sym)	\
195 	ldr	x, sym;		\
196 	ldr	x, [x, got]
197 #define	GOT_INIT(got,gotsym,pclabel) \
198 	ldr	got, gotsym;	\
199 	pclabel: add	got, got, pc
200 #ifdef __thumb__
201 #define	GOT_INITSYM(gotsym,pclabel) \
202 	.align 0;		\
203 	gotsym: .word _C_LABEL(_GLOBAL_OFFSET_TABLE_) - (pclabel+4)
204 #else
205 #define	GOT_INITSYM(gotsym,pclabel) \
206 	.align 0;		\
207 	gotsym: .word _C_LABEL(_GLOBAL_OFFSET_TABLE_) - (pclabel+8)
208 #endif
209 
210 #ifdef __STDC__
211 #define	PIC_SYM(x,y)	x ## ( ## y ## )
212 #else
213 #define	PIC_SYM(x,y)	x/**/(/**/y/**/)
214 #endif
215 
216 #else
217 #define	REL_SYM(a, b)	(a)
218 #define	PLT_SYM(x)	x
219 #define	GOT_SYM(x)	x
220 #define	GOT_GET(x,got,sym)	\
221 	ldr	x, sym;
222 #define	GOT_INIT(got,gotsym,pclabel)
223 #define	GOT_INITSYM(gotsym,pclabel)
224 #define	PIC_SYM(x,y)	x
225 #endif	/* __PIC__ */
226 
227 /*
228  * Annoyingly, gas on arm seems to generate _two_ NUL-terminated
229  * strings for
230  *
231  *	.asciz "foo" "bar"
232  *
233  * instead of concatenating it into a single NUL-terminated string as
234  * on other architectures.
235  *
236  * To work around this, we concatenate into a single NUL-terminated by:
237  *
238  *	.ascii "foo"
239  *	.asciz "bar"
240  */
241 #define _IDENTSTR(x)	.pushsection ".ident","MS",%progbits,1;		\
242 			x;						\
243 			.popsection
244 
245 #ifdef _NETBSD_REVISIONID
246 #define	RCSID(_s)							\
247 	_IDENTSTR(.asciz _s);						\
248 	_IDENTSTR(.ascii "$"; .ascii "NetBSD: "; .ascii __FILE__;	\
249 	    .ascii " "; .ascii _NETBSD_REVISIONID; .asciz " $")
250 #else
251 #define	RCSID(_s)	_IDENTSTR(.asciz _s)
252 #endif
253 
254 #define	WEAK_ALIAS(alias,sym)						\
255 	.weak alias;							\
256 	alias = sym
257 
258 /*
259  * STRONG_ALIAS: create a strong alias.
260  */
261 #define STRONG_ALIAS(alias,sym)						\
262 	.globl alias;							\
263 	alias = sym
264 
265 #ifdef __STDC__
266 #define	WARN_REFERENCES(sym,msg)					\
267 	.pushsection .gnu.warning. ## sym;				\
268 	.ascii msg;							\
269 	.popsection
270 #else
271 #define	WARN_REFERENCES(sym,msg)					\
272 	.pushsection .gnu.warning./**/sym;				\
273 	.ascii msg;							\
274 	.popsection
275 #endif /* __STDC__ */
276 
277 #ifdef __thumb__
278 # define XPUSH		push
279 # define XPOP		pop
280 # define XPOPRET	pop	{pc}
281 #else
282 # define XPUSH		stmfd	sp!,
283 # define XPOP		ldmfd	sp!,
284 # ifdef _ARM_ARCH_5
285 #  define XPOPRET	ldmfd	sp!, {pc}
286 # else
287 #  define XPOPRET	ldmfd	sp!, {lr}; mov pc, lr
288 # endif
289 #endif
290 
291 #if defined(__aarch64__)
292 # define RET		ret
293 #elif defined (_ARM_ARCH_4T)
294 # define RET		bx		lr
295 # define RETr(r)	bx		r
296 # if defined(__thumb__)
297 #  if defined(_ARM_ARCH_7)
298 #   define RETc(c)	it c; __CONCAT(bx,c)	lr
299 #  endif
300 # else
301 #  define RETc(c)	__CONCAT(bx,c)	lr
302 # endif
303 #else
304 # define RET		mov		pc, lr
305 # define RETr(r)	mov		pc, r
306 # define RETc(c)	__CONCAT(mov,c)	pc, lr
307 #endif
308 
309 #ifdef _ARM_ARCH_7
310 #define KMODTRAMPOLINE(n)			\
311 _ENTRY(__wrap_ ## n)				\
312 	movw	ip, #:lower16:n;	\
313 	movt	ip, #:upper16:n;	\
314 	bx	ip
315 #elif defined(_ARM_ARCH_4T)
316 #define KMODTRAMPOLINE(n)	\
317 _ENTRY(__wrap_ ## n)		\
318 	ldr	ip, [pc];	\
319 	bx	ip;		\
320 	.word	n
321 #else
322 #define KMODTRAMPOLINE(n)	\
323 _ENTRY(__wrap_ ## n)		\
324 	ldr	pc, [pc, #-4];	\
325 	.word	n
326 #endif
327 
328 #endif /* !_ARM_ASM_H_ */
329