xref: /freebsd-9.3-release/sys/i386/include/asmacros.h

/*-
 * Copyright (c) 1993 The Regents of the University of California.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */

#ifndef _MACHINE_ASMACROS_H_
#define _MACHINE_ASMACROS_H_

#include <sys/cdefs.h>

/* XXX too much duplication in various asm*.h's. */

/*
 * CNAME is used to manage the relationship between symbol names in C
 * and the equivalent assembly language names.  CNAME is given a name as
 * it would be used in a C program.  It expands to the equivalent assembly
 * language name.
 */
#define CNAME(csym)		csym

#define ALIGN_DATA	.p2align 2	/* 4 byte alignment, zero filled */
#ifdef GPROF
#define ALIGN_TEXT	.p2align 4,0x90	/* 16-byte alignment, nop filled */
#else
#define ALIGN_TEXT	.p2align 2,0x90	/* 4-byte alignment, nop filled */
#endif
#define SUPERALIGN_TEXT	.p2align 4,0x90	/* 16-byte alignment, nop filled */

#define GEN_ENTRY(name)		ALIGN_TEXT; .globl CNAME(name); \
				.type CNAME(name),@function; CNAME(name):
#define NON_GPROF_ENTRY(name)	GEN_ENTRY(name)
#define NON_GPROF_RET		.byte 0xc3	/* opcode for `ret' */

#define	END(name)		.size name, . - name

#ifdef GPROF
/*
 * __mcount is like [.]mcount except that doesn't require its caller to set
 * up a frame pointer.  It must be called before pushing anything onto the
 * stack.  gcc should eventually generate code to call __mcount in most
 * cases.  This would make -pg in combination with -fomit-frame-pointer
 * useful.  gcc has a configuration variable PROFILE_BEFORE_PROLOGUE to
 * allow profiling before setting up the frame pointer, but this is
 * inadequate for good handling of special cases, e.g., -fpic works best
 * with profiling after the prologue.
 *
 * [.]mexitcount is a new function to support non-statistical profiling if an
 * accurate clock is available.  For C sources, calls to it are generated
 * by the FreeBSD extension `-mprofiler-epilogue' to gcc.  It is best to
 * call [.]mexitcount at the end of a function like the MEXITCOUNT macro does,
 * but gcc currently generates calls to it at the start of the epilogue to
 * avoid problems with -fpic.
 *
 * [.]mcount and __mcount may clobber the call-used registers and %ef.
 * [.]mexitcount may clobber %ecx and %ef.
 *
 * Cross-jumping makes non-statistical profiling timing more complicated.
 * It is handled in many cases by calling [.]mexitcount before jumping.  It
 * is handled for conditional jumps using CROSSJUMP() and CROSSJUMP_LABEL().
 * It is handled for some fault-handling jumps by not sharing the exit
 * routine.
 *
 * ALTENTRY() must be before a corresponding ENTRY() so that it can jump to
 * the main entry point.  Note that alt entries are counted twice.  They
 * have to be counted as ordinary entries for gprof to get the call times
 * right for the ordinary entries.
 *
 * High local labels are used in macros to avoid clashes with local labels
 * in functions.
 *
 * Ordinary `ret' is used instead of a macro `RET' because there are a lot
 * of `ret's.  0xc3 is the opcode for `ret' (`#define ret ... ret' can't
 * be used because this file is sometimes preprocessed in traditional mode).
 * `ret' clobbers eflags but this doesn't matter.
 */
#define ALTENTRY(name)		GEN_ENTRY(name) ; MCOUNT ; MEXITCOUNT ; jmp 9f
#define	CROSSJUMP(jtrue, label, jfalse) \
	jfalse 8f; MEXITCOUNT; jmp __CONCAT(to,label); 8:
#define CROSSJUMPTARGET(label) \
	ALIGN_TEXT; __CONCAT(to,label): ; MCOUNT; jmp label
#define ENTRY(name)		GEN_ENTRY(name) ; 9: ; MCOUNT
#define FAKE_MCOUNT(caller)	pushl caller ; call __mcount ; popl %ecx
#define MCOUNT			call __mcount
#define MCOUNT_LABEL(name)	GEN_ENTRY(name) ; nop ; ALIGN_TEXT
#ifdef GUPROF
#define MEXITCOUNT		call .mexitcount
#define ret			MEXITCOUNT ; NON_GPROF_RET
#else
#define MEXITCOUNT
#endif

#else /* !GPROF */
/*
 * ALTENTRY() has to align because it is before a corresponding ENTRY().
 * ENTRY() has to align to because there may be no ALTENTRY() before it.
 * If there is a previous ALTENTRY() then the alignment code for ENTRY()
 * is empty.
 */
#define ALTENTRY(name)		GEN_ENTRY(name)
#define	CROSSJUMP(jtrue, label, jfalse)	jtrue label
#define	CROSSJUMPTARGET(label)
#define ENTRY(name)		GEN_ENTRY(name)
#define FAKE_MCOUNT(caller)
#define MCOUNT
#define MCOUNT_LABEL(name)
#define MEXITCOUNT
#endif /* GPROF */

#ifdef LOCORE
/*
 * Convenience macro for declaring interrupt entry points.
 */
#define	IDTVEC(name)	ALIGN_TEXT; .globl __CONCAT(X,name); \
			.type __CONCAT(X,name),@function; __CONCAT(X,name):

/*
 * Macros to create and destroy a trap frame.
 */
#define	PUSH_FRAME							\
	pushl	$0 ;		/* dummy error code */			\
	pushl	$0 ;		/* dummy trap type */			\
	pushal ;		/* 8 ints */				\
	pushl	%ds ;		/* save data and extra segments ... */	\
	pushl	%es ;							\
	pushl	%fs

#define	POP_FRAME							\
	popl	%fs ;							\
	popl	%es ;							\
	popl	%ds ;							\
	popal ;								\
	addl	$4+4,%esp

/*
 * Access per-CPU data.
 */
#define	PCPU(member)	%fs:PC_ ## member

#define	PCPU_ADDR(member, reg)						\
	movl %fs:PC_PRVSPACE, reg ;					\
	addl $PC_ ## member, reg

/*
 * Setup the kernel segment registers.
 */
#define	SET_KERNEL_SREGS						\
	movl	$KDSEL, %eax ;	/* reload with kernel's data segment */	\
	movl	%eax, %ds ;						\
	movl	%eax, %es ;						\
	movl	$KPSEL, %eax ;	/* reload with per-CPU data segment */	\
	movl	%eax, %fs

#ifdef XEN
#define LOAD_CR3(reg)          \
        movl    reg,PCPU(CR3); \
        pushl   %ecx ;         \
        pushl   %edx ;         \
        pushl   %esi ;         \
        pushl   reg ;          \
        call    xen_load_cr3 ;     \
        addl    $4,%esp ;      \
        popl    %esi ;         \
        popl    %edx ;         \
        popl    %ecx ;         \

#define READ_CR3(reg)   movl PCPU(CR3),reg;
#define LLDT(arg)                 \
        pushl   %edx ;                    \
        pushl   %eax ;                    \
        xorl    %eax,%eax ;               \
        movl    %eax,%gs ;                \
        call    i386_reset_ldt ;          \
        popl    %eax ;                    \
        popl    %edx
#define CLI             call ni_cli
#else
#define LOAD_CR3(reg)   movl reg,%cr3;
#define READ_CR3(reg)   movl %cr3,reg;
#define LLDT(arg)       lldt arg;
#define CLI             cli
#endif /* !XEN */


#endif /* LOCORE */

#ifdef __STDC__
#define ELFNOTE(name, type, desctype, descdata...) \
.pushsection .note.name                 ;       \
  .align 4                              ;       \
  .long 2f - 1f         /* namesz */    ;       \
  .long 4f - 3f         /* descsz */    ;       \
  .long type                            ;       \
1:.asciz #name                          ;       \
2:.align 4                              ;       \
3:desctype descdata                     ;       \
4:.align 4                              ;       \
.popsection
#else /* !__STDC__, i.e. -traditional */
#define ELFNOTE(name, type, desctype, descdata) \
.pushsection .note.name                 ;       \
  .align 4                              ;       \
  .long 2f - 1f         /* namesz */    ;       \
  .long 4f - 3f         /* descsz */    ;       \
  .long type                            ;       \
1:.asciz "name"                         ;       \
2:.align 4                              ;       \
3:desctype descdata                     ;       \
4:.align 4                              ;       \
.popsection
#endif /* __STDC__ */

#endif /* !_MACHINE_ASMACROS_H_ */