/*
   * Linux/PARISC Project (http://www.parisc-linux.org/)
   *
   * HP-UX System Call Wrapper routines and System Call Return Path
   *
   * Copyright (C) 2000 Hewlett-Packard (John Marvin)
   *
   *    This program is free software; you can redistribute it and/or modify
   *    it under the terms of the GNU General Public License as published by
   *    the Free Software Foundation; either version 2, or (at your option)
   *    any later version.
   *
   *    This program 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 General Public License for more details.
   *
   *    You should have received a copy of the GNU General Public License
   *    along with this program; if not, write to the Free Software
   *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   */
  
  #ifdef CONFIG_64BIT
  #warning PA64 support needs more work...did first cut
  #endif
  
  #include <asm/asm-offsets.h>
  #include <asm/assembly.h>
  #include <asm/signal.h>
  #include <linux/linkage.h>
  
  	.level	LEVEL
  	.text
  
  	/* These should probably go in a header file somewhere.
  	 * They are duplicated in kernel/wrappers.S
  	 * Possibly we should consider consolidating these
  	 * register save/restore macros.
  	 */
  	.macro	reg_save regs
  #ifdef CONFIG_64BIT
  #warning NEEDS WORK for 64-bit
  #endif
  	STREG	%r3, PT_GR3(\regs)
  	STREG	%r4, PT_GR4(\regs)
  	STREG	%r5, PT_GR5(\regs)
  	STREG	%r6, PT_GR6(\regs)
  	STREG	%r7, PT_GR7(\regs)
  	STREG	%r8, PT_GR8(\regs)
  	STREG	%r9, PT_GR9(\regs)
  	STREG	%r10,PT_GR10(\regs)
  	STREG	%r11,PT_GR11(\regs)
  	STREG	%r12,PT_GR12(\regs)
  	STREG	%r13,PT_GR13(\regs)
  	STREG	%r14,PT_GR14(\regs)
  	STREG	%r15,PT_GR15(\regs)
  	STREG	%r16,PT_GR16(\regs)
  	STREG	%r17,PT_GR17(\regs)
  	STREG	%r18,PT_GR18(\regs)
  	.endm
  
  	.macro	reg_restore regs
  	LDREG	PT_GR3(\regs), %r3
  	LDREG	PT_GR4(\regs), %r4
  	LDREG	PT_GR5(\regs), %r5
  	LDREG	PT_GR6(\regs), %r6
  	LDREG	PT_GR7(\regs), %r7
  	LDREG	PT_GR8(\regs), %r8
  	LDREG	PT_GR9(\regs), %r9
  	LDREG	PT_GR10(\regs),%r10
  	LDREG	PT_GR11(\regs),%r11
  	LDREG	PT_GR12(\regs),%r12
  	LDREG	PT_GR13(\regs),%r13
  	LDREG	PT_GR14(\regs),%r14
  	LDREG	PT_GR15(\regs),%r15
  	LDREG	PT_GR16(\regs),%r16
  	LDREG	PT_GR17(\regs),%r17
  	LDREG	PT_GR18(\regs),%r18
  	.endm
  
  
  	.import sys_fork
  
  ENTRY(hpux_fork_wrapper)
  	ldo	TASK_REGS-TASK_SZ_ALGN-64(%r30),%r1	    ;! get pt regs
  							    ;! pointer in task
  	reg_save %r1
  
  	STREG	%r2,-20(%r30)
  	ldo	64(%r30),%r30
  	STREG	%r2,PT_GR19(%r1)	;! save for child
  	STREG	%r30,PT_GR21(%r1)	;! save for child
  
  	LDREG	PT_GR30(%r1),%r25
  	mtctl	%r25,%cr29
  	copy	%r1,%r24
  	bl	sys_clone,%r2
  	ldi	SIGCHLD,%r26
  
  	LDREG	-84(%r30),%r2
  fork_return:
  	ldo	-64(%r30),%r30
  	ldo	TASK_REGS-TASK_SZ_ALGN-64(%r30),%r1	    ;! get pt regs
  
  	reg_restore %r1
  
  	/*
  	 * HP-UX wants pid (child gets parent pid, parent gets child pid)
  	 * in r28 and a flag in r29 (r29 == 1 for child, 0 for parent).
  	 * Linux fork returns 0 for child, pid for parent. Since HP-UX
  	 * libc stub throws away parent pid and returns 0 for child,
  	 * we'll just return 0 for parent pid now. Only applications
  	 * that jump directly to the gateway page (not supported) will
  	 * know the difference. We can fix this later if necessary.
  	 */
  
  	ldo	-1024(%r0),%r1
  	comb,>>=,n %r28,%r1,fork_exit  /* just let the syscall exit handle it */
  	or,=	%r28,%r0,%r0
  	or,tr	%r0,%r0,%r29	/* r28 <> 0, we are parent, set r29 to 0 */
  	ldo	1(%r0),%r29 	/* r28 == 0, we are child,  set r29 to 1 */
  
  fork_exit:
  	bv	%r0(%r2)
  	nop
  ENDPROC(hpux_fork_wrapper)
  
  	/* Set the return value for the child */
  
  ENTRY(hpux_child_return)
  #if defined(CONFIG_SMP) || defined(CONFIG_PREEMPT)
  	bl,n	schedule_tail, %r2
  #endif
  
  	LDREG	TASK_PT_GR19-TASK_SZ_ALGN-128(%r30),%r2
  	b fork_return
  	copy %r0,%r28
  ENDPROC(hpux_child_return)
  
  	.import hpux_execve
  
  ENTRY(hpux_execv_wrapper)
  	copy %r0,%r24  /* NULL environment */
  
  ENTRY(hpux_execve_wrapper)
  
  	ldo	TASK_REGS-TASK_SZ_ALGN-64(%r30),%r1	    ;! get pt regs
  
  	/*
  	 * Do we need to save/restore r3-r18 here?
  	 * I don't think so. why would new thread need old
  	 * threads registers?
  	 */
  
  	/* Store arg0, arg1 and arg2 so that hpux_execve will find them */
  
  	STREG %r26,PT_GR26(%r1)
  	STREG %r25,PT_GR25(%r1)
  	STREG %r24,PT_GR24(%r1)
  
  	STREG %r2,-20(%r30)
  	ldo 64(%r30),%r30
  	bl hpux_execve,%r2
  	copy %r1,%arg0
  
  	ldo -64(%r30),%r30
  	LDREG	-20(%r30),%r2
  
  	/* If exec succeeded we need to load the args */
  
  	ldo -1024(%r0),%r1
  	comb,>>= %r28,%r1,exec_error
  	copy %r2,%r19
  	ldo	-TASK_SZ_ALGN-64(%r30),%r1	   ;! get task ptr
  	LDREG	TASK_PT_GR26(%r1),%r26
  	LDREG	TASK_PT_GR25(%r1),%r25
  	LDREG	TASK_PT_GR24(%r1),%r24
  	LDREG	TASK_PT_GR23(%r1),%r23
  	copy %r0,%r2	/* Flag to syscall_exit not to clear args */
  
  exec_error:
  	bv %r0(%r19)
  	nop
  ENDPROC(hpux_execv_wrapper)
  
  	.import hpux_pipe
  
  	/* HP-UX expects pipefd's returned in r28 & r29 */
  
  ENTRY(hpux_pipe_wrapper)
  	STREG %r2,-20(%r30)
  	ldo 64(%r30),%r30
  	bl hpux_pipe,%r2
  	ldo -56(%r30),%r26 /* pass local array to hpux_pipe */
  
  
  	ldo -1024(%r0),%r1
  	comb,>>= %r28,%r1,pipe_exit /* let syscall exit handle it */
  	LDREG	-84(%r30),%r2
  
  	/* if success, load fd's from stack array */
  
  	LDREG	-56(%r30),%r28
  	LDREG	-52(%r30),%r29
  
  pipe_exit:
  	bv %r0(%r2)
  	ldo -64(%r30),%r30
  ENDPROC(hpux_pipe_wrapper)
  
  	.import syscall_exit
  
  ENTRY(hpux_syscall_exit)
  	/*
  	 *
  	 * HP-UX call return conventions:
  	 *
  	 * if error:
  	 *	 r22 = 1
  	 *	 r28 = errno value
  	 *	 r29 = secondary return value
  	 * else
  	 *	 r22 = 0
  	 *	 r28 = return value
  	 *	 r29 = secondary return value
  	 *
  	 * For now, we'll just check to see if r28 is < (unsigned long)-1024
  	 * (to handle addresses > 2 Gb) and if so set r22 to zero. If not,
  	 * we'll complement r28 and set r22 to 1. Wrappers will be
  	 * needed for syscalls that care about the secondary return value.
  	 * The wrapper may also need a way of avoiding the following code,
  	 * but we'll deal with that when it becomes necessary.
  	 */
  
  	ldo -1024(%r0),%r1
  	comb,<< %r28,%r1,no_error
  	copy %r0,%r22
  	subi 0,%r28,%r28
  	ldo 1(%r0),%r22
  
  no_error:
  	b,n syscall_exit
  ENDPROC(hpux_syscall_exit)
  
  	.import hpux_unimplemented
  
  ENTRY(hpux_unimplemented_wrapper)
  	b hpux_unimplemented
  	STREG %r22,-64(%r30)  /* overwrite arg8 with syscall number */
  ENDPROC(hpux_unimplemented_wrapper)