xref: /freebsd/sys/amd64/include/asmacros.h (revision 5e53a4f90f82c4345f277dd87cc9292f26e04a29)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1993 The Regents of the University of California.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  * $FreeBSD$
32  */
33 
34 #ifndef _MACHINE_ASMACROS_H_
35 #define _MACHINE_ASMACROS_H_
36 
37 #include <sys/cdefs.h>
38 
39 /* XXX too much duplication in various asm*.h's. */
40 
41 /*
42  * CNAME is used to manage the relationship between symbol names in C
43  * and the equivalent assembly language names.  CNAME is given a name as
44  * it would be used in a C program.  It expands to the equivalent assembly
45  * language name.
46  */
47 #define CNAME(csym)		csym
48 
49 #define ALIGN_DATA	.p2align 3	/* 8 byte alignment, zero filled */
50 #ifdef GPROF
51 #define ALIGN_TEXT	.p2align 4,0x90	/* 16-byte alignment, nop filled */
52 #else
53 #define ALIGN_TEXT	.p2align 4,0x90	/* 16-byte alignment, nop filled */
54 #endif
55 #define SUPERALIGN_TEXT	.p2align 4,0x90	/* 16-byte alignment, nop filled */
56 
57 #define GEN_ENTRY(name)		ALIGN_TEXT; .globl CNAME(name); \
58 				.type CNAME(name),@function; CNAME(name):
59 #define NON_GPROF_ENTRY(name)	GEN_ENTRY(name)
60 #define NON_GPROF_RET		.byte 0xc3	/* opcode for `ret' */
61 
62 #define	END(name)		.size name, . - name
63 
64 #ifdef GPROF
65 /*
66  * __mcount is like [.]mcount except that doesn't require its caller to set
67  * up a frame pointer.  It must be called before pushing anything onto the
68  * stack.  gcc should eventually generate code to call __mcount in most
69  * cases.  This would make -pg in combination with -fomit-frame-pointer
70  * useful.  gcc has a configuration variable PROFILE_BEFORE_PROLOGUE to
71  * allow profiling before setting up the frame pointer, but this is
72  * inadequate for good handling of special cases, e.g., -fpic works best
73  * with profiling after the prologue.
74  *
75  * [.]mexitcount is a new function to support non-statistical profiling if an
76  * accurate clock is available.  For C sources, calls to it are generated
77  * by the FreeBSD extension `-mprofiler-epilogue' to gcc.  It is best to
78  * call [.]mexitcount at the end of a function like the MEXITCOUNT macro does,
79  * but gcc currently generates calls to it at the start of the epilogue to
80  * avoid problems with -fpic.
81  *
82  * [.]mcount and __mcount may clobber the call-used registers and %ef.
83  * [.]mexitcount may clobber %ecx and %ef.
84  *
85  * Cross-jumping makes non-statistical profiling timing more complicated.
86  * It is handled in many cases by calling [.]mexitcount before jumping.  It
87  * is handled for conditional jumps using CROSSJUMP() and CROSSJUMP_LABEL().
88  * It is handled for some fault-handling jumps by not sharing the exit
89  * routine.
90  *
91  * ALTENTRY() must be before a corresponding ENTRY() so that it can jump to
92  * the main entry point.  Note that alt entries are counted twice.  They
93  * have to be counted as ordinary entries for gprof to get the call times
94  * right for the ordinary entries.
95  *
96  * High local labels are used in macros to avoid clashes with local labels
97  * in functions.
98  *
99  * Ordinary `ret' is used instead of a macro `RET' because there are a lot
100  * of `ret's.  0xc3 is the opcode for `ret' (`#define ret ... ret' can't
101  * be used because this file is sometimes preprocessed in traditional mode).
102  * `ret' clobbers eflags but this doesn't matter.
103  */
104 #define ALTENTRY(name)		GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f
105 #define	CROSSJUMP(jtrue, label, jfalse) \
106 	jfalse 8f; MEXITCOUNT; jmp __CONCAT(to,label); 8:
107 #define CROSSJUMPTARGET(label) \
108 	ALIGN_TEXT; __CONCAT(to,label): ; MCOUNT; jmp label
109 #define ENTRY(name)		GEN_ENTRY(name) ; 9: ; MCOUNT
110 #define FAKE_MCOUNT(caller)	pushq caller ; call __mcount ; popq %rcx
111 #define MCOUNT			call __mcount
112 #define MCOUNT_LABEL(name)	GEN_ENTRY(name) ; nop ; ALIGN_TEXT
113 #ifdef GUPROF
114 #define MEXITCOUNT		call .mexitcount
115 #define ret			MEXITCOUNT ; NON_GPROF_RET
116 #else
117 #define MEXITCOUNT
118 #endif
119 
120 #else /* !GPROF */
121 /*
122  * ALTENTRY() has to align because it is before a corresponding ENTRY().
123  * ENTRY() has to align to because there may be no ALTENTRY() before it.
124  * If there is a previous ALTENTRY() then the alignment code for ENTRY()
125  * is empty.
126  */
127 #define ALTENTRY(name)		GEN_ENTRY(name)
128 #define	CROSSJUMP(jtrue, label, jfalse)	jtrue label
129 #define	CROSSJUMPTARGET(label)
130 #define ENTRY(name)		GEN_ENTRY(name)
131 #define FAKE_MCOUNT(caller)
132 #define MCOUNT
133 #define MCOUNT_LABEL(name)
134 #define MEXITCOUNT
135 #endif /* GPROF */
136 
137 /*
138  * Convenience for adding frame pointers to hand-coded ASM.  Useful for
139  * DTrace, HWPMC, and KDB.
140  */
141 #define PUSH_FRAME_POINTER	\
142 	pushq	%rbp ;		\
143 	movq	%rsp, %rbp ;
144 #define POP_FRAME_POINTER	\
145 	popq	%rbp
146 
147 #ifdef LOCORE
148 /*
149  * Convenience macro for declaring interrupt entry points.
150  */
151 #define	IDTVEC(name)	ALIGN_TEXT; .globl __CONCAT(X,name); \
152 			.type __CONCAT(X,name),@function; __CONCAT(X,name):
153 
154 /*
155  * Macros to create and destroy a trap frame.
156  */
157 #define PUSH_FRAME							\
158 	subq	$TF_RIP,%rsp ;	/* skip dummy tf_err and tf_trapno */	\
159 	testb	$SEL_RPL_MASK,TF_CS(%rsp) ; /* come from kernel? */	\
160 	jz	1f ;		/* Yes, dont swapgs again */		\
161 	swapgs ;							\
162 1:	movq	%rdi,TF_RDI(%rsp) ;					\
163 	movq	%rsi,TF_RSI(%rsp) ;					\
164 	movq	%rdx,TF_RDX(%rsp) ;					\
165 	movq	%rcx,TF_RCX(%rsp) ;					\
166 	movq	%r8,TF_R8(%rsp) ;					\
167 	movq	%r9,TF_R9(%rsp) ;					\
168 	movq	%rax,TF_RAX(%rsp) ;					\
169 	movq	%rbx,TF_RBX(%rsp) ;					\
170 	movq	%rbp,TF_RBP(%rsp) ;					\
171 	movq	%r10,TF_R10(%rsp) ;					\
172 	movq	%r11,TF_R11(%rsp) ;					\
173 	movq	%r12,TF_R12(%rsp) ;					\
174 	movq	%r13,TF_R13(%rsp) ;					\
175 	movq	%r14,TF_R14(%rsp) ;					\
176 	movq	%r15,TF_R15(%rsp) ;					\
177 	movw	%fs,TF_FS(%rsp) ;					\
178 	movw	%gs,TF_GS(%rsp) ;					\
179 	movw	%es,TF_ES(%rsp) ;					\
180 	movw	%ds,TF_DS(%rsp) ;					\
181 	movl	$TF_HASSEGS,TF_FLAGS(%rsp) ;				\
182 	cld ;								\
183 	testb	$SEL_RPL_MASK,TF_CS(%rsp) ; /* come from kernel ? */	\
184 	jz	2f ;		/* yes, leave PCB_FULL_IRET alone */	\
185 	movq	PCPU(CURPCB),%r8 ;					\
186 	andl	$~PCB_FULL_IRET,PCB_FLAGS(%r8) ;			\
187 2:
188 
189 #define POP_FRAME							\
190 	movq	TF_RDI(%rsp),%rdi ;					\
191 	movq	TF_RSI(%rsp),%rsi ;					\
192 	movq	TF_RDX(%rsp),%rdx ;					\
193 	movq	TF_RCX(%rsp),%rcx ;					\
194 	movq	TF_R8(%rsp),%r8 ;					\
195 	movq	TF_R9(%rsp),%r9 ;					\
196 	movq	TF_RAX(%rsp),%rax ;					\
197 	movq	TF_RBX(%rsp),%rbx ;					\
198 	movq	TF_RBP(%rsp),%rbp ;					\
199 	movq	TF_R10(%rsp),%r10 ;					\
200 	movq	TF_R11(%rsp),%r11 ;					\
201 	movq	TF_R12(%rsp),%r12 ;					\
202 	movq	TF_R13(%rsp),%r13 ;					\
203 	movq	TF_R14(%rsp),%r14 ;					\
204 	movq	TF_R15(%rsp),%r15 ;					\
205 	testb	$SEL_RPL_MASK,TF_CS(%rsp) ; /* come from kernel? */	\
206 	jz	1f ;		/* keep kernel GS.base */		\
207 	cli ;								\
208 	swapgs ;							\
209 1:	addq	$TF_RIP,%rsp	/* skip over tf_err, tf_trapno */
210 
211 /*
212  * Access per-CPU data.
213  */
214 #define	PCPU(member)	%gs:PC_ ## member
215 #define	PCPU_ADDR(member, reg)					\
216 	movq %gs:PC_PRVSPACE, reg ;				\
217 	addq $PC_ ## member, reg
218 
219 #endif /* LOCORE */
220 
221 #ifdef __STDC__
222 #define ELFNOTE(name, type, desctype, descdata...) \
223 .pushsection .note.name                 ;       \
224   .align 4                              ;       \
225   .long 2f - 1f         /* namesz */    ;       \
226   .long 4f - 3f         /* descsz */    ;       \
227   .long type                            ;       \
228 1:.asciz #name                          ;       \
229 2:.align 4                              ;       \
230 3:desctype descdata                     ;       \
231 4:.align 4                              ;       \
232 .popsection
233 #else /* !__STDC__, i.e. -traditional */
234 #define ELFNOTE(name, type, desctype, descdata) \
235 .pushsection .note.name                 ;       \
236   .align 4                              ;       \
237   .long 2f - 1f         /* namesz */    ;       \
238   .long 4f - 3f         /* descsz */    ;       \
239   .long type                            ;       \
240 1:.asciz "name"                         ;       \
241 2:.align 4                              ;       \
242 3:desctype descdata                     ;       \
243 4:.align 4                              ;       \
244 .popsection
245 #endif /* __STDC__ */
246 
247 #endif /* !_MACHINE_ASMACROS_H_ */
248