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