2 * Copyright (c) 1993 The Regents of the University of California.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
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
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32 #ifndef _MACHINE_ASMACROS_H_
33 #define _MACHINE_ASMACROS_H_
35 #include <sys/cdefs.h>
37 /* XXX too much duplication in various asm*.h's. */
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
45 #define CNAME(csym) csym
47 #define ALIGN_DATA .p2align 2 /* 4 byte alignment, zero filled */
49 #define ALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
51 #define ALIGN_TEXT .p2align 2,0x90 /* 4-byte alignment, nop filled */
53 #define SUPERALIGN_TEXT .p2align 4,0x90 /* 16-byte alignment, nop filled */
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' */
60 #define END(name) .size name, . - name
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.
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.
80 * [.]mcount and __mcount may clobber the call-used registers and %ef.
81 * [.]mexitcount may clobber %ecx and %ef.
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
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.
94 * High local labels are used in macros to avoid clashes with local labels
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.
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) pushl caller ; call __mcount ; popl %ecx
109 #define MCOUNT call __mcount
110 #define MCOUNT_LABEL(name) GEN_ENTRY(name) ; nop ; ALIGN_TEXT
112 #define MEXITCOUNT call .mexitcount
113 #define ret MEXITCOUNT ; NON_GPROF_RET
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()
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)
131 #define MCOUNT_LABEL(name)
137 * Convenience macro for declaring interrupt entry points.
139 #define IDTVEC(name) ALIGN_TEXT; .globl __CONCAT(X,name); \
140 .type __CONCAT(X,name),@function; __CONCAT(X,name):
143 * Macros to create and destroy a trap frame.
146 pushl $0 ; /* dummy error code */ \
147 pushl $0 ; /* dummy trap type */ \
148 pushal ; /* 8 ints */ \
149 pushl %ds ; /* save data and extra segments ... */ \
161 * Access per-CPU data.
163 #define PCPU(member) %fs:PC_ ## member
165 #define PCPU_ADDR(member, reg) \
166 movl %fs:PC_PRVSPACE, reg ; \
167 addl $PC_ ## member, reg
170 * Setup the kernel segment registers.
172 #define SET_KERNEL_SREGS \
173 movl $KDSEL, %eax ; /* reload with kernel's data segment */ \
176 movl $KPSEL, %eax ; /* reload with per-CPU data segment */ \
180 #define LOAD_CR3(reg) \
181 movl reg,PCPU(CR3); \
186 call xen_load_cr3 ; \
192 #define READ_CR3(reg) movl PCPU(CR3),reg;
198 call i386_reset_ldt ; \
201 #define CLI call ni_cli
203 #define LOAD_CR3(reg) movl reg,%cr3;
204 #define READ_CR3(reg) movl %cr3,reg;
205 #define LLDT(arg) lldt arg;
213 #define ELFNOTE(name, type, desctype, descdata...) \
214 .pushsection .note.name ; \
216 .long 2f - 1f /* namesz */ ; \
217 .long 4f - 3f /* descsz */ ; \
221 3:desctype descdata ; \
224 #else /* !__STDC__, i.e. -traditional */
225 #define ELFNOTE(name, type, desctype, descdata) \
226 .pushsection .note.name ; \
228 .long 2f - 1f /* namesz */ ; \
229 .long 4f - 3f /* descsz */ ; \
233 3:desctype descdata ; \
236 #endif /* __STDC__ */
238 #endif /* !_MACHINE_ASMACROS_H_ */