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	.endm
161
162	.macro	PUSH_FRAME
163	pushl	$0		/* dummy error code */
164	pushl	$0		/* dummy trap type */
165	PUSH_FRAME2
166	.endm
167
168/*
169 * Access per-CPU data.
170 */
171#define	PCPU(member)	%fs:PC_ ## member
172
173#define	PCPU_ADDR(member, reg)						\
174	movl %fs:PC_PRVSPACE, reg ;					\
175	addl $PC_ ## member, reg
176
177/*
178 * Setup the kernel segment registers.
179 */
180	.macro	SET_KERNEL_SREGS
181	movl	$KDSEL, %eax	/* reload with kernel's data segment */
182	movl	%eax, %ds
183	movl	%eax, %es
184	movl	$KPSEL, %eax	/* reload with per-CPU data segment */
185	movl	%eax, %fs
186	.endm
187
188	.macro	NMOVE_STACKS
189	movl	PCPU(KESP0), %edx
190	movl	$TF_SZ, %ecx
191	testl	$PSL_VM, TF_EFLAGS(%esp)
192	jz	.L\@.1
193	addl	$VM86_STACK_SPACE, %ecx
194.L\@.1:	subl	%ecx, %edx
195	movl	%edx, %edi
196	movl	%esp, %esi
197	rep; movsb
198	movl	%edx, %esp
199	.endm
200
201	.macro	LOAD_KCR3
202	call	.L\@.1
203.L\@.1:	popl	%eax
204	movl	(tramp_idleptd - .L\@.1)(%eax), %eax
205	movl	%eax, %cr3
206	.endm
207
208	.macro	MOVE_STACKS
209	LOAD_KCR3
210	NMOVE_STACKS
211	.endm
212
213	.macro	KENTER
214	testl	$PSL_VM, TF_EFLAGS(%esp)
215	jz	.L\@.1
216	LOAD_KCR3
217	movl	PCPU(CURPCB), %eax
218	testl	$PCB_VM86CALL, PCB_FLAGS(%eax)
219	jnz	.L\@.3
220	NMOVE_STACKS
221	movl	$handle_ibrs_entry,%edx
222	call	*%edx
223	jmp	.L\@.3
224.L\@.1:	testb	$SEL_RPL_MASK, TF_CS(%esp)
225	jz	.L\@.3
226.L\@.2:	MOVE_STACKS
227	movl	$handle_ibrs_entry,%edx
228	call	*%edx
229.L\@.3:
230	.endm
231
232#endif /* LOCORE */
233
234#ifdef __STDC__
235#define ELFNOTE(name, type, desctype, descdata...) \
236.pushsection .note.name                 ;       \
237  .align 4                              ;       \
238  .long 2f - 1f         /* namesz */    ;       \
239  .long 4f - 3f         /* descsz */    ;       \
240  .long type                            ;       \
2411:.asciz #name                          ;       \
2422:.align 4                              ;       \
2433:desctype descdata                     ;       \
2444:.align 4                              ;       \
245.popsection
246#else /* !__STDC__, i.e. -traditional */
247#define ELFNOTE(name, type, desctype, descdata) \
248.pushsection .note.name                 ;       \
249  .align 4                              ;       \
250  .long 2f - 1f         /* namesz */    ;       \
251  .long 4f - 3f         /* descsz */    ;       \
252  .long type                            ;       \
2531:.asciz "name"                         ;       \
2542:.align 4                              ;       \
2553:desctype descdata                     ;       \
2564:.align 4                              ;       \
257.popsection
258#endif /* __STDC__ */
259
260#endif /* !_MACHINE_ASMACROS_H_ */
261