xref: /freebsd/sys/i386/include/asmacros.h (revision 3cbb4cc200f8a0ad7ed08233425ea54524a21f1c)
1 /* -*- mode: asm -*- */
2 /*-
3  * SPDX-License-Identifier: BSD-3-Clause
4  *
5  * Copyright (c) 1993 The Regents of the University of California.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. Neither the name of the University nor the names of its contributors
17  *    may be used to endorse or promote products derived from this software
18  *    without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30  * SUCH DAMAGE.
31  *
32  * $FreeBSD$
33  */
34 
35 #ifndef _MACHINE_ASMACROS_H_
36 #define _MACHINE_ASMACROS_H_
37 
38 #include <sys/cdefs.h>
39 
40 /* XXX too much duplication in various asm*.h's. */
41 
42 /*
43  * CNAME is used to manage the relationship between symbol names in C
44  * and the equivalent assembly language names.  CNAME is given a name as
45  * it would be used in a C program.  It expands to the equivalent assembly
46  * language name.
47  */
48 #define CNAME(csym)		csym
49 
50 #define ALIGN_DATA	.p2align 2	/* 4 byte alignment, zero filled */
51 #ifdef GPROF
52 #define ALIGN_TEXT	.p2align 4,0x90	/* 16-byte alignment, nop filled */
53 #else
54 #define ALIGN_TEXT	.p2align 2,0x90	/* 4-byte alignment, nop filled */
55 #endif
56 #define SUPERALIGN_TEXT	.p2align 4,0x90	/* 16-byte alignment, nop filled */
57 
58 #define GEN_ENTRY(name)		ALIGN_TEXT; .globl CNAME(name); \
59 				.type CNAME(name),@function; CNAME(name):
60 #define NON_GPROF_ENTRY(name)	GEN_ENTRY(name)
61 #define NON_GPROF_RET		.byte 0xc3	/* opcode for `ret' */
62 
63 #define	END(name)		.size name, . - name
64 
65 #ifdef GPROF
66 /*
67  * __mcount is like [.]mcount except that doesn't require its caller to set
68  * up a frame pointer.  It must be called before pushing anything onto the
69  * stack.  gcc should eventually generate code to call __mcount in most
70  * cases.  This would make -pg in combination with -fomit-frame-pointer
71  * useful.  gcc has a configuration variable PROFILE_BEFORE_PROLOGUE to
72  * allow profiling before setting up the frame pointer, but this is
73  * inadequate for good handling of special cases, e.g., -fpic works best
74  * with profiling after the prologue.
75  *
76  * [.]mexitcount is a new function to support non-statistical profiling if an
77  * accurate clock is available.  For C sources, calls to it are generated
78  * by the FreeBSD extension `-mprofiler-epilogue' to gcc.  It is best to
79  * call [.]mexitcount at the end of a function like the MEXITCOUNT macro does,
80  * but gcc currently generates calls to it at the start of the epilogue to
81  * avoid problems with -fpic.
82  *
83  * [.]mcount and __mcount may clobber the call-used registers and %ef.
84  * [.]mexitcount may clobber %ecx and %ef.
85  *
86  * Cross-jumping makes non-statistical profiling timing more complicated.
87  * It is handled in many cases by calling [.]mexitcount before jumping.  It
88  * is handled for conditional jumps using CROSSJUMP() and CROSSJUMP_LABEL().
89  * It is handled for some fault-handling jumps by not sharing the exit
90  * routine.
91  *
92  * ALTENTRY() must be before a corresponding ENTRY() so that it can jump to
93  * the main entry point.  Note that alt entries are counted twice.  They
94  * have to be counted as ordinary entries for gprof to get the call times
95  * right for the ordinary entries.
96  *
97  * High local labels are used in macros to avoid clashes with local labels
98  * in functions.
99  *
100  * Ordinary `ret' is used instead of a macro `RET' because there are a lot
101  * of `ret's.  0xc3 is the opcode for `ret' (`#define ret ... ret' can't
102  * be used because this file is sometimes preprocessed in traditional mode).
103  * `ret' clobbers eflags but this doesn't matter.
104  */
105 #define ALTENTRY(name)		GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f
106 #define	CROSSJUMP(jtrue, label, jfalse) \
107 	jfalse 8f; MEXITCOUNT; jmp __CONCAT(to,label); 8:
108 #define CROSSJUMPTARGET(label) \
109 	ALIGN_TEXT; __CONCAT(to,label): ; MCOUNT; jmp label
110 #define ENTRY(name)		GEN_ENTRY(name) ; 9: ; MCOUNT
111 #define FAKE_MCOUNT(caller)	pushl caller ; call *__mcountp ; popl %ecx
112 #define MCOUNT			call *__mcountp
113 #define MCOUNT_LABEL(name)	GEN_ENTRY(name) ; nop ; ALIGN_TEXT
114 #ifdef GUPROF
115 #define MEXITCOUNT		call *__mexitcountp
116 #define ret			MEXITCOUNT ; NON_GPROF_RET
117 #else
118 #define MEXITCOUNT
119 #endif
120 
121 #else /* !GPROF */
122 /*
123  * ALTENTRY() has to align because it is before a corresponding ENTRY().
124  * ENTRY() has to align to because there may be no ALTENTRY() before it.
125  * If there is a previous ALTENTRY() then the alignment code for ENTRY()
126  * is empty.
127  */
128 #define ALTENTRY(name)		GEN_ENTRY(name)
129 #define	CROSSJUMP(jtrue, label, jfalse)	jtrue label
130 #define	CROSSJUMPTARGET(label)
131 #define ENTRY(name)		GEN_ENTRY(name)
132 #define FAKE_MCOUNT(caller)
133 #define MCOUNT
134 #define MCOUNT_LABEL(name)
135 #define MEXITCOUNT
136 #endif /* GPROF */
137 
138 #ifdef LOCORE
139 
140 #define	GSEL_KPL	0x0020	/* GSEL(GCODE_SEL, SEL_KPL) */
141 #define	SEL_RPL_MASK	0x0003
142 
143 /*
144  * Convenience macro for declaring interrupt entry points.
145  */
146 #define	IDTVEC(name)	ALIGN_TEXT; .globl __CONCAT(X,name); \
147 			.type __CONCAT(X,name),@function; __CONCAT(X,name):
148 
149 /*
150  * Macros to create and destroy a trap frame.
151  */
152 	.macro	PUSH_FRAME2
153 	pushal
154 	pushl	$0
155 	movw	%ds,(%esp)
156 	pushl	$0
157 	movw	%es,(%esp)
158 	pushl	$0
159 	movw	%fs,(%esp)
160 	movl	%esp,%ebp
161 	.endm
162 
163 	.macro	PUSH_FRAME
164 	pushl	$0		/* dummy error code */
165 	pushl	$0		/* dummy trap type */
166 	PUSH_FRAME2
167 	.endm
168 
169 /*
170  * Access per-CPU data.
171  */
172 #define	PCPU(member)	%fs:PC_ ## member
173 
174 #define	PCPU_ADDR(member, reg)						\
175 	movl %fs:PC_PRVSPACE, reg ;					\
176 	addl $PC_ ## member, reg
177 
178 /*
179  * Setup the kernel segment registers.
180  */
181 	.macro	SET_KERNEL_SREGS
182 	movl	$KDSEL, %eax	/* reload with kernel's data segment */
183 	movl	%eax, %ds
184 	movl	%eax, %es
185 	movl	$KPSEL, %eax	/* reload with per-CPU data segment */
186 	movl	%eax, %fs
187 	.endm
188 
189 	.macro	NMOVE_STACKS
190 	movl	PCPU(KESP0), %edx
191 	movl	$TF_SZ, %ecx
192 	testl	$PSL_VM, TF_EFLAGS(%esp)
193 	jz	.L\@.1
194 	addl	$VM86_STACK_SPACE, %ecx
195 .L\@.1:	subl	%ecx, %edx
196 	movl	%edx, %edi
197 	movl	%esp, %esi
198 	rep; movsb
199 	movl	%edx, %esp
200 	.endm
201 
202 	.macro	LOAD_KCR3
203 	call	.L\@.1
204 .L\@.1:	popl	%eax
205 	movl	(tramp_idleptd - .L\@.1)(%eax), %eax
206 	movl	%eax, %cr3
207 	.endm
208 
209 	.macro	MOVE_STACKS
210 	LOAD_KCR3
211 	NMOVE_STACKS
212 	.endm
213 
214 	.macro	KENTER
215 	testl	$PSL_VM, TF_EFLAGS(%esp)
216 	jz	.L\@.1
217 	LOAD_KCR3
218 	movl	PCPU(CURPCB), %eax
219 	testl	$PCB_VM86CALL, PCB_FLAGS(%eax)
220 	jnz	.L\@.3
221 	NMOVE_STACKS
222 	movl	$handle_ibrs_entry,%edx
223 	call	*%edx
224 	jmp	.L\@.3
225 .L\@.1:	testb	$SEL_RPL_MASK, TF_CS(%esp)
226 	jz	.L\@.3
227 .L\@.2:	MOVE_STACKS
228 	movl	$handle_ibrs_entry,%edx
229 	call	*%edx
230 .L\@.3:
231 	.endm
232 
233 #endif /* LOCORE */
234 
235 #ifdef __STDC__
236 #define ELFNOTE(name, type, desctype, descdata...) \
237 .pushsection .note.name                 ;       \
238   .align 4                              ;       \
239   .long 2f - 1f         /* namesz */    ;       \
240   .long 4f - 3f         /* descsz */    ;       \
241   .long type                            ;       \
242 1:.asciz #name                          ;       \
243 2:.align 4                              ;       \
244 3:desctype descdata                     ;       \
245 4:.align 4                              ;       \
246 .popsection
247 #else /* !__STDC__, i.e. -traditional */
248 #define ELFNOTE(name, type, desctype, descdata) \
249 .pushsection .note.name                 ;       \
250   .align 4                              ;       \
251   .long 2f - 1f         /* namesz */    ;       \
252   .long 4f - 3f         /* descsz */    ;       \
253   .long type                            ;       \
254 1:.asciz "name"                         ;       \
255 2:.align 4                              ;       \
256 3:desctype descdata                     ;       \
257 4:.align 4                              ;       \
258 .popsection
259 #endif /* __STDC__ */
260 
261 #endif /* !_MACHINE_ASMACROS_H_ */
262