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      1 /*	$NetBSD: asm.h,v 1.39 2025/05/07 16:26:47 uwe 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 #define _INSN_SIZE	(2)
     77 #else
     78 #define THUMB_INSN(n)
     79 #define _INSN_SIZE	(4)
     80 #endif
     81 
     82 #define	__BIT(n)	(1 << (n))
     83 #define __BITS(hi,lo)	((~((~0)<<((hi)+1)))&((~0)<<(lo)))
     84 
     85 #define __LOWEST_SET_BIT(__mask) ((((__mask) - 1) & (__mask)) ^ (__mask))
     86 #define __SHIFTOUT(__x, __mask) (((__x) & (__mask)) / __LOWEST_SET_BIT(__mask))
     87 #define __SHIFTIN(__x, __mask) ((__x) * __LOWEST_SET_BIT(__mask))
     88 
     89 #define _C_LABEL(x)	x
     90 #define	_ASM_LABEL(x)	x
     91 
     92 #ifdef __STDC__
     93 # define __CONCAT(x,y)	x ## y
     94 # define __STRING(x)	#x
     95 #else
     96 # define __CONCAT(x,y)	x/**/y
     97 # define __STRING(x)	"x"
     98 #endif
     99 
    100 #ifndef _ALIGN_TEXT
    101 # define _ALIGN_TEXT .align 2
    102 #endif
    103 
    104 #ifndef _TEXT_SECTION
    105 #define _TEXT_SECTION	.text
    106 #endif
    107 
    108 #ifdef __arm__
    109 
    110 	.syntax		unified
    111 
    112 /*
    113  * gas/arm uses @ as a single comment character and thus cannot be used here
    114  * Instead it recognised the # instead of an @ symbols in .type directives
    115  * We define a couple of macros so that assembly code will not be dependent
    116  * on one or the other.
    117  */
    118 #define _ASM_TYPE_FUNCTION	%function
    119 #define _ASM_TYPE_OBJECT	%object
    120 #define _THUMB_ENTRY(x) \
    121 	_TEXT_SECTION; _ALIGN_TEXT; .globl x; .type x,_ASM_TYPE_FUNCTION; \
    122 	.thumb_func; .code 16; x:
    123 #define _ARM_ENTRY(x) \
    124 	_TEXT_SECTION; _ALIGN_TEXT; .globl x; .type x,_ASM_TYPE_FUNCTION; \
    125 	.code 32; x:
    126 #ifdef __thumb__
    127 #define	_ENTRY(x)	_THUMB_ENTRY(x)
    128 #else
    129 #define	_ENTRY(x)	_ARM_ENTRY(x)
    130 #endif
    131 #define	_END(x)		.size x,.-x
    132 
    133 #ifdef GPROF
    134 # define _PROF_PROLOGUE	\
    135 	mov ip, lr; bl __mcount
    136 #else
    137 # define _PROF_PROLOGUE
    138 #endif
    139 #endif
    140 
    141 #ifdef __aarch64__
    142 #define _ASM_TYPE_FUNCTION	@function
    143 #define _ASM_TYPE_OBJECT	@object
    144 #define _ENTRY(x) \
    145 	_TEXT_SECTION; _ALIGN_TEXT; .globl x; .type x,_ASM_TYPE_FUNCTION; x:
    146 #define	_END(x)		.size x,.-x
    147 
    148 #ifdef GPROF
    149 # define _PROF_PROLOGUE	\
    150 	stp	x29, x30, [sp, #-16]!;	\
    151 	mov	fp, sp;			\
    152 	bl	__mcount; 		\
    153 	ldp	x29, x30, [sp], #16;
    154 #else
    155 # define _PROF_PROLOGUE
    156 #endif
    157 
    158 #ifdef __PIC__
    159 #define GOTREF(x)		:got:x
    160 #define GOTLO12(x)		:got_lo12:x
    161 #else
    162 #define GOTREF(x)		x
    163 #define GOTLO12(x)		:lo12:x
    164 #endif
    165 #endif
    166 
    167 #ifdef ARMV85_BTI
    168 #define	_BTI_PROLOGUE \
    169 	.byte	0x5F, 0x24, 0x03, 0xD5	/* the "bti c" instruction */
    170 #else
    171 #define	_BTI_PROLOGUE		/* nothing */
    172 #endif
    173 
    174 #define	ENTRY(y)		_ENTRY(_C_LABEL(y)); _BTI_PROLOGUE ; _PROF_PROLOGUE
    175 #define	ENTRY_NP(y)		_ENTRY(_C_LABEL(y)); _BTI_PROLOGUE
    176 #define	ENTRY_NBTI(y)		_ENTRY(_C_LABEL(y))
    177 #define	END(y)			_END(_C_LABEL(y))
    178 #define	ARM_ENTRY(y)		_ARM_ENTRY(_C_LABEL(y)); _PROF_PROLOGUE
    179 #define	ARM_ENTRY_NP(y)		_ARM_ENTRY(_C_LABEL(y))
    180 #define	THUMB_ENTRY(y)		_THUMB_ENTRY(_C_LABEL(y)); _PROF_PROLOGUE
    181 #define	THUMB_ENTRY_NP(y)	_THUMB_ENTRY(_C_LABEL(y))
    182 #define	ASENTRY(y)		_ENTRY(_ASM_LABEL(y)); _PROF_PROLOGUE
    183 #define	ASENTRY_NP(y)		_ENTRY(_ASM_LABEL(y))
    184 #define	ASEND(y)		_END(_ASM_LABEL(y))
    185 #define	ARM_ASENTRY(y)		_ARM_ENTRY(_ASM_LABEL(y)); _PROF_PROLOGUE
    186 #define	ARM_ASENTRY_NP(y)	_ARM_ENTRY(_ASM_LABEL(y))
    187 #define	THUMB_ASENTRY(y)	_THUMB_ENTRY(_ASM_LABEL(y)); _PROF_PROLOGUE
    188 #define	THUMB_ASENTRY_NP(y)	_THUMB_ENTRY(_ASM_LABEL(y))
    189 
    190 #define	ASMSTR		.asciz
    191 
    192 #ifdef __PIC__
    193 #define	REL_SYM(a, b)	((a) - (b))
    194 #define	PLT_SYM(x)	x
    195 #define	GOT_SYM(x)	PIC_SYM(x, GOT)
    196 #define	GOT_GET(x,got,sym)	\
    197 	ldr	x, sym;		\
    198 	ldr	x, [x, got]
    199 
    200 /*
    201  * Load _GLOBAL_OFFSET_TABLE_ address into register:
    202  *
    203  * 0:	GOT_INIT(rX, .Lgot)
    204  *	...
    205  *
    206  *      // and in the data after the function
    207  *	GOT_INITSYM(.Lgot, 0b)
    208  */
    209 #define	GOT_INIT(Rgot, gotsym)	  \
    210 	ldr	Rgot, gotsym	; \
    211 	add	Rgot, Rgot, pc
    212 #define	GOT_INITSYM(gotsym, initlabel)	\
    213 	.align 0;		\
    214 	gotsym:	.word _C_LABEL(_GLOBAL_OFFSET_TABLE_) - (initlabel+(1+2)*_INSN_SIZE)
    215 
    216 #ifdef __STDC__
    217 #define	PIC_SYM(x,y)	x(y)
    218 #else
    219 #define	PIC_SYM(x,y)	x/**/(/**/y/**/)
    220 #endif
    221 
    222 #else
    223 #define	REL_SYM(a, b)	(a)
    224 #define	PLT_SYM(x)	x
    225 #define	GOT_SYM(x)	x
    226 #define	GOT_GET(x,got,sym)	\
    227 	ldr	x, sym;
    228 #define	GOT_INIT(Rgot, gotsym)
    229 #define	GOT_INITSYM(gotsym, initlabel)
    230 #define	PIC_SYM(x,y)	x
    231 #endif	/* __PIC__ */
    232 
    233 /*
    234  * Annoyingly, gas on arm seems to generate _two_ NUL-terminated
    235  * strings for
    236  *
    237  *	.asciz "foo" "bar"
    238  *
    239  * instead of concatenating it into a single NUL-terminated string as
    240  * on other architectures.
    241  *
    242  * To work around this, we concatenate into a single NUL-terminated by:
    243  *
    244  *	.ascii "foo"
    245  *	.asciz "bar"
    246  */
    247 #define _IDENTSTR(x)	.pushsection ".ident","MS",%progbits,1;		\
    248 			x;						\
    249 			.popsection
    250 
    251 #ifdef _NETBSD_REVISIONID
    252 #define	RCSID(_s)							\
    253 	_IDENTSTR(.asciz _s);						\
    254 	_IDENTSTR(.ascii "$"; .ascii "NetBSD: "; .ascii __FILE__;	\
    255 	    .ascii " "; .ascii _NETBSD_REVISIONID; .asciz " $")
    256 #else
    257 #define	RCSID(_s)	_IDENTSTR(.asciz _s)
    258 #endif
    259 
    260 #define	WEAK_ALIAS(alias,sym)						\
    261 	.weak alias;							\
    262 	alias = sym
    263 
    264 /*
    265  * STRONG_ALIAS: create a strong alias.
    266  */
    267 #define STRONG_ALIAS(alias,sym)						\
    268 	.globl alias;							\
    269 	alias = sym
    270 
    271 #ifdef __STDC__
    272 #define	WARN_REFERENCES(sym,msg)					\
    273 	.pushsection .gnu.warning.sym;					\
    274 	.ascii msg;							\
    275 	.popsection
    276 #else
    277 #define	WARN_REFERENCES(sym,msg)					\
    278 	.pushsection .gnu.warning./**/sym;				\
    279 	.ascii msg;							\
    280 	.popsection
    281 #endif /* __STDC__ */
    282 
    283 #ifdef __thumb__
    284 # define XPUSH		push
    285 # define XPOP		pop
    286 # define XPOPRET	pop	{pc}
    287 #else
    288 # define XPUSH		stmfd	sp!,
    289 # define XPOP		ldmfd	sp!,
    290 # ifdef _ARM_ARCH_5
    291 #  define XPOPRET	ldmfd	sp!, {pc}
    292 # else
    293 #  define XPOPRET	ldmfd	sp!, {lr}; mov pc, lr
    294 # endif
    295 #endif
    296 
    297 #if defined(__aarch64__)
    298 # define RET		ret
    299 #elif defined (_ARM_ARCH_4T)
    300 # define RET		bx		lr
    301 # define RETr(r)	bx		r
    302 # if defined(__thumb__)
    303 #  if defined(_ARM_ARCH_7)
    304 #   define RETc(c)	it c; __CONCAT(bx,c)	lr
    305 #  endif
    306 # else
    307 #  define RETc(c)	__CONCAT(bx,c)	lr
    308 # endif
    309 #else
    310 # define RET		mov		pc, lr
    311 # define RETr(r)	mov		pc, r
    312 # define RETc(c)	__CONCAT(mov,c)	pc, lr
    313 #endif
    314 
    315 #ifdef _ARM_ARCH_7
    316 #define KMODTRAMPOLINE(n)			\
    317 _ENTRY(__wrap_ ## n)				\
    318 	movw	ip, #:lower16:n;	\
    319 	movt	ip, #:upper16:n;	\
    320 	bx	ip
    321 #elif defined(_ARM_ARCH_4T)
    322 #define KMODTRAMPOLINE(n)	\
    323 _ENTRY(__wrap_ ## n)		\
    324 	ldr	ip, [pc];	\
    325 	bx	ip;		\
    326 	.word	n
    327 #else
    328 #define KMODTRAMPOLINE(n)	\
    329 _ENTRY(__wrap_ ## n)		\
    330 	ldr	pc, [pc, #-4];	\
    331 	.word	n
    332 #endif
    333 
    334 #endif /* !_ARM_ASM_H_ */
    335