glibc/sysdeps/unix/sysv/linux/ia64/sysdep.h

/* Copyright (C) 1999-2021 Free Software Foundation, Inc.
   This file is part of the GNU C Library.
   Written by Jes Sorensen, <Jes.Sorensen@cern.ch>, April 1999.
   Based on code originally written by David Mosberger-Tang

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#ifndef _LINUX_IA64_SYSDEP_H
#define _LINUX_IA64_SYSDEP_H 1

#include <sysdeps/unix/sysdep.h>
#include <sysdeps/unix/sysv/linux/sysdep.h>
#include <sysdeps/ia64/sysdep.h>
#include <dl-sysdep.h>
#include <tls.h>
#include <asm/break.h>

/* In order to get __set_errno() definition in INLINE_SYSCALL.  */
#ifndef __ASSEMBLER__
#include <errno.h>
#endif

/* As of GAS v2.4.90.0.7, including a ".align" directive inside a
   function will cause bad unwind info to be emitted (GAS doesn't know
   how to account for the padding introduced by the .align directive).
   Turning on this macro will work around this bug by introducing the
   necessary padding explicitly. */
#define GAS_ALIGN_BREAKS_UNWIND_INFO

/* For Linux we can use the system call table in the header file
	/usr/include/asm/unistd.h
   of the kernel.  But these symbols do not follow the SYS_* syntax
   so we have to redefine the `SYS_ify' macro here.  */
#undef SYS_ify
#define SYS_ify(syscall_name)	__NR_##syscall_name

#if defined USE_DL_SYSINFO \
	&& (IS_IN (libc) \
	    || IS_IN (libpthread) || IS_IN (librt))
# define IA64_USE_NEW_STUB
#else
# undef IA64_USE_NEW_STUB
#endif

#ifdef __ASSEMBLER__

#undef CALL_MCOUNT
#ifdef PROF
# define CALL_MCOUNT							\
	.data;								\
1:	data8 0;	/* XXX fixme: use .xdata8 once labels work */	\
	.previous;							\
	.prologue;							\
	.save ar.pfs, r40;						\
	alloc out0 = ar.pfs, 8, 0, 4, 0;				\
	mov out1 = gp;							\
	.save rp, out2;							\
	mov out2 = rp;							\
	.body;								\
	;;								\
	addl out3 = @ltoff(1b), gp;					\
	br.call.sptk.many rp = _mcount					\
	;;
#else
# define CALL_MCOUNT	/* Do nothing. */
#endif

/* Linux uses a negative return value to indicate syscall errors, unlike
   most Unices, which use the condition codes' carry flag.

   Since version 2.1 the return value of a system call might be negative
   even if the call succeeded.  E.g., the `lseek' system call might return
   a large offset.  Therefore we must not anymore test for < 0, but test
   for a real error by making sure the value in %d0 is a real error
   number.  Linus said he will make sure the no syscall returns a value
   in -1 .. -4095 as a valid result so we can savely test with -4095.  */

/* We don't want the label for the error handler to be visible in the symbol
   table when we define it here.  */
#undef SYSCALL_ERROR_LABEL
#define SYSCALL_ERROR_LABEL __syscall_error

#undef PSEUDO
#define	PSEUDO(name, syscall_name, args)	\
  ENTRY(name)					\
    DO_CALL (SYS_ify(syscall_name));		\
	cmp.eq p6,p0=-1,r10;			\
(p6)	br.cond.spnt.few __syscall_error;

#define DO_CALL_VIA_BREAK(num)			\
	mov r15=num;				\
	break __IA64_BREAK_SYSCALL

#ifdef IA64_USE_NEW_STUB
# ifdef SHARED
#  define DO_CALL(num)				\
	.prologue;				\
	adds r2 = SYSINFO_OFFSET, r13;;		\
	ld8 r2 = [r2];				\
	.save ar.pfs, r11;			\
	mov r11 = ar.pfs;;			\
	.body;					\
	mov r15 = num;				\
	mov b7 = r2;				\
	br.call.sptk.many b6 = b7;;		\
	.restore sp;				\
	mov ar.pfs = r11;			\
	.prologue;				\
	.body
# else /* !SHARED */
#  define DO_CALL(num)				\
	.prologue;				\
	mov r15 = num;				\
	movl r2 = _dl_sysinfo;;			\
	ld8 r2 = [r2];				\
	.save ar.pfs, r11;			\
	mov r11 = ar.pfs;;			\
	.body;					\
	mov b7 = r2;				\
	br.call.sptk.many b6 = b7;;		\
	.restore sp;				\
	mov ar.pfs = r11;			\
	.prologue;				\
	.body
# endif
#else
# define DO_CALL(num)				DO_CALL_VIA_BREAK(num)
#endif

#undef PSEUDO_END
#define PSEUDO_END(name)	.endp C_SYMBOL_NAME(name);

#undef PSEUDO_NOERRNO
#define	PSEUDO_NOERRNO(name, syscall_name, args)	\
  ENTRY(name)						\
    DO_CALL (SYS_ify(syscall_name));

#undef PSEUDO_END_NOERRNO
#define PSEUDO_END_NOERRNO(name)	.endp C_SYMBOL_NAME(name);

#undef PSEUDO_ERRVAL
#define	PSEUDO_ERRVAL(name, syscall_name, args)	\
  ENTRY(name)					\
    DO_CALL (SYS_ify(syscall_name));		\
	cmp.eq p6,p0=-1,r10;			\
(p6)	mov r10=r8;


#undef PSEUDO_END_ERRVAL
#define PSEUDO_END_ERRVAL(name)	.endp C_SYMBOL_NAME(name);

#undef END
#define END(name)						\
	.size	C_SYMBOL_NAME(name), . - C_SYMBOL_NAME(name) ;	\
	.endp	C_SYMBOL_NAME(name)

#define ret			br.ret.sptk.few b0
#define ret_NOERRNO		ret
#define ret_ERRVAL		ret

#else /* not __ASSEMBLER__ */

#undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
#define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1

#define BREAK_INSN_1(num) "break " #num ";;\n\t"
#define BREAK_INSN(num) BREAK_INSN_1(num)

/* On IA-64 we have stacked registers for passing arguments.  The
   "out" registers end up being the called function's "in"
   registers.

   Also, since we have plenty of registers we have two return values
   from a syscall.  r10 is set to -1 on error, whilst r8 contains the
   (non-negative) errno on error or the return value on success.
 */

#ifdef IA64_USE_NEW_STUB

# define INTERNAL_SYSCALL_NCS(name, nr, args...)			      \
({									      \
    LOAD_ARGS_##nr (args)						      \
    register long _r8 __asm ("r8");					      \
    register long _r10 __asm ("r10");					      \
    register long _r15 __asm ("r15") = name;				      \
    register void *_b7 __asm ("b7") = ((tcbhead_t *)__thread_self)->__private;\
    LOAD_REGS_##nr							      \
    /*									      \
     * Don't specify any unwind info here.  We mark ar.pfs as		      \
     * clobbered.  This will force the compiler to save ar.pfs		      \
     * somewhere and emit appropriate unwind info for that save.	      \
     */									      \
    __asm __volatile ("br.call.sptk.many b6=%0;;\n"			      \
		      : "=b"(_b7), "=r" (_r8), "=r" (_r10), "=r" (_r15)	      \
			ASM_OUTARGS_##nr				      \
		      : "0" (_b7), "3" (_r15) ASM_ARGS_##nr		      \
		      : "memory", "ar.pfs" ASM_CLOBBERS_##nr);		      \
    _r10 == -1 ? -_r8 : _r8;						      \
})

#else /* !IA64_USE_NEW_STUB */

# define INTERNAL_SYSCALL_NCS(name, nr, args...)		\
({								\
    LOAD_ARGS_##nr (args)					\
    register long _r8 asm ("r8");				\
    register long _r10 asm ("r10");				\
    register long _r15 asm ("r15") = name;			\
    LOAD_REGS_##nr						\
    __asm __volatile (BREAK_INSN (__IA64_BREAK_SYSCALL)		\
		      : "=r" (_r8), "=r" (_r10), "=r" (_r15)	\
			ASM_OUTARGS_##nr			\
		      : "2" (_r15) ASM_ARGS_##nr		\
		      : "memory" ASM_CLOBBERS_##nr);		\
    _r10 == -1 ? -_r8 : _r8;					\
})

#endif /* !IA64_USE_NEW_STUB */

#define INTERNAL_SYSCALL(name, nr, args...)	\
  INTERNAL_SYSCALL_NCS (__NR_##name, nr, ##args)

#define LOAD_ARGS_0()
#define LOAD_REGS_0
#define LOAD_ARGS_1(a1)					\
  long _arg1 = (long) (a1);				\
  LOAD_ARGS_0 ()
#define LOAD_REGS_1					\
  register long _out0 asm ("out0") = _arg1;		\
  LOAD_REGS_0
#define LOAD_ARGS_2(a1, a2)				\
  long _arg2 = (long) (a2);				\
  LOAD_ARGS_1 (a1)
#define LOAD_REGS_2					\
  register long _out1 asm ("out1") = _arg2;		\
  LOAD_REGS_1
#define LOAD_ARGS_3(a1, a2, a3)				\
  long _arg3 = (long) (a3);				\
  LOAD_ARGS_2 (a1, a2)
#define LOAD_REGS_3					\
  register long _out2 asm ("out2") = _arg3;		\
  LOAD_REGS_2
#define LOAD_ARGS_4(a1, a2, a3, a4)			\
  long _arg4 = (long) (a4);				\
  LOAD_ARGS_3 (a1, a2, a3)
#define LOAD_REGS_4					\
  register long _out3 asm ("out3") = _arg4;		\
  LOAD_REGS_3
#define LOAD_ARGS_5(a1, a2, a3, a4, a5)			\
  long _arg5 = (long) (a5);				\
  LOAD_ARGS_4 (a1, a2, a3, a4)
#define LOAD_REGS_5					\
  register long _out4 asm ("out4") = _arg5;		\
  LOAD_REGS_4
#define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6)		\
  long _arg6 = (long) (a6);	    			\
  LOAD_ARGS_5 (a1, a2, a3, a4, a5)
#define LOAD_REGS_6					\
  register long _out5 asm ("out5") = _arg6;		\
  LOAD_REGS_5

#define ASM_OUTARGS_0
#define ASM_OUTARGS_1	ASM_OUTARGS_0, "=r" (_out0)
#define ASM_OUTARGS_2	ASM_OUTARGS_1, "=r" (_out1)
#define ASM_OUTARGS_3	ASM_OUTARGS_2, "=r" (_out2)
#define ASM_OUTARGS_4	ASM_OUTARGS_3, "=r" (_out3)
#define ASM_OUTARGS_5	ASM_OUTARGS_4, "=r" (_out4)
#define ASM_OUTARGS_6	ASM_OUTARGS_5, "=r" (_out5)

#ifdef IA64_USE_NEW_STUB
#define ASM_ARGS_0
#define ASM_ARGS_1	ASM_ARGS_0, "4" (_out0)
#define ASM_ARGS_2	ASM_ARGS_1, "5" (_out1)
#define ASM_ARGS_3	ASM_ARGS_2, "6" (_out2)
#define ASM_ARGS_4	ASM_ARGS_3, "7" (_out3)
#define ASM_ARGS_5	ASM_ARGS_4, "8" (_out4)
#define ASM_ARGS_6	ASM_ARGS_5, "9" (_out5)
#else
#define ASM_ARGS_0
#define ASM_ARGS_1	ASM_ARGS_0, "3" (_out0)
#define ASM_ARGS_2	ASM_ARGS_1, "4" (_out1)
#define ASM_ARGS_3	ASM_ARGS_2, "5" (_out2)
#define ASM_ARGS_4	ASM_ARGS_3, "6" (_out3)
#define ASM_ARGS_5	ASM_ARGS_4, "7" (_out4)
#define ASM_ARGS_6	ASM_ARGS_5, "8" (_out5)
#endif

#define ASM_CLOBBERS_0	ASM_CLOBBERS_1, "out0"
#define ASM_CLOBBERS_1	ASM_CLOBBERS_2, "out1"
#define ASM_CLOBBERS_2	ASM_CLOBBERS_3, "out2"
#define ASM_CLOBBERS_3	ASM_CLOBBERS_4, "out3"
#define ASM_CLOBBERS_4	ASM_CLOBBERS_5, "out4"
#define ASM_CLOBBERS_5	ASM_CLOBBERS_6, "out5"
#define ASM_CLOBBERS_6_COMMON	, "out6", "out7",			\
  /* Non-stacked integer registers, minus r8, r10, r15.  */		\
  "r2", "r3", "r9", "r11", "r13", "r14", "r16", "r17", "r18",		\
  "r19", "r20", "r21", "r22", "r23", "r24", "r25", "r26", "r27",	\
  "r28", "r29", "r30", "r31",						\
  /* Predicate registers.  */						\
  "p6", "p7", "p8", "p9", "p10", "p11", "p12", "p13", "p14", "p15",	\
  /* Non-rotating fp registers.  */					\
  "f6", "f7", "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15",	\
  /* Branch registers.  */						\
  "b6"

#ifdef IA64_USE_NEW_STUB
# define ASM_CLOBBERS_6	ASM_CLOBBERS_6_COMMON
#else
# define ASM_CLOBBERS_6	ASM_CLOBBERS_6_COMMON , "b7"
#endif

#endif /* not __ASSEMBLER__ */

/* Pointer mangling support.  */
#if IS_IN (rtld)
/* We cannot use the thread descriptor because in ld.so we use setjmp
   earlier than the descriptor is initialized.  */
#else
# ifdef __ASSEMBLER__
#  define PTR_MANGLE(reg, tmpreg) \
        add	tmpreg=-16,r13		\
        ;;				\
        ld8	tmpreg=[tmpreg]		\
        ;;				\
        xor	reg=reg, tmpreg
#  define PTR_DEMANGLE(reg, tmpreg) PTR_MANGLE (reg, tmpreg)
# else
#  define PTR_MANGLE(var) \
  (var) = (void *) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
#  define PTR_DEMANGLE(var)	PTR_MANGLE (var)
# endif
#endif

#endif /* linux/ia64/sysdep.h */