/*
   *
   * Linux/PARISC Project (http://www.parisc-linux.org/)
   *
   * System call entry code Copyright (c) Matthew Wilcox 1999 <willy@bofh.ai>
   * Licensed under the GNU GPL.
   * thanks to Philipp Rumpf, Mike Shaver and various others
   * sorry about the wall, puffin..
   */
  
  #include <asm/assembly.h>
  #include <asm/asm-offsets.h>
  #include <asm/unistd.h>
  #include <asm/errno.h>
  #include <linux/linkage.h>
  
  	.level	LEVEL
  	.text
  
  	.import hpux_call_table
  	.import hpux_syscall_exit,code
  
  	.align	PAGE_SIZE
  ENTRY(hpux_gateway_page)
  	nop
  #ifdef CONFIG_64BIT
  #warning NEEDS WORK for 64-bit
  #endif
  	ldw     -64(%r30), %r29                 ;! 8th argument
  	ldw	-60(%r30), %r19			;! 7th argument
  	ldw	-56(%r30), %r20			;! 6th argument
  	ldw	-52(%r30), %r21			;! 5th argument
  	gate	.+8, %r0			/* become privileged */
  	mtsp	%r0,%sr4			/* get kernel space into sr4 */
  	mtsp	%r0,%sr5			/* get kernel space into sr5 */
  	mtsp	%r0,%sr6			/* get kernel space into sr6 */
  	mfsp    %sr7,%r1                        /* save user sr7 */
  	mtsp    %r1,%sr3                        /* and store it in sr3 */
  
  	mtctl   %r30,%cr28
  	mfctl   %cr30,%r1
  	xor     %r1,%r30,%r30                   /* ye olde xor trick */
  	xor     %r1,%r30,%r1
  	xor     %r1,%r30,%r30
  	ldo     TASK_SZ_ALGN+FRAME_SIZE(%r30),%r30  /* set up kernel stack */
  
  	/* N.B.: It is critical that we don't set sr7 to 0 until r30
  	 *       contains a valid kernel stack pointer. It is also
  	 *       critical that we don't start using the kernel stack
  	 *       until after sr7 has been set to 0.
  	 */
  
  	mtsp	%r0,%sr7			/* get kernel space into sr7 */
  	STREG   %r1,TASK_PT_GR30-TASK_SZ_ALGN-FRAME_SIZE(%r30) /* save usp */
  	ldo     -TASK_SZ_ALGN-FRAME_SIZE(%r30),%r1   /* get task ptr in %r1 */
  
  	/* Save some registers for sigcontext and potential task
  	   switch (see entry.S for the details of which ones are
  	   saved/restored).  TASK_PT_PSW is zeroed so we can see whether
  	   a process is on a syscall or not.  For an interrupt the real
  	   PSW value is stored.  This is needed for gdb and sys_ptrace. */
  	STREG	%r0,  TASK_PT_PSW(%r1)
  	STREG	%r2,  TASK_PT_GR2(%r1)		/* preserve rp */
  	STREG   %r19, TASK_PT_GR19(%r1)         /* 7th argument */
  	STREG   %r20, TASK_PT_GR20(%r1)         /* 6th argument */
  	STREG   %r21, TASK_PT_GR21(%r1)         /* 5th argument */
  	STREG   %r22, TASK_PT_GR22(%r1)         /* syscall # */
  	STREG	%r23, TASK_PT_GR23(%r1)		/* 4th argument */
  	STREG	%r24, TASK_PT_GR24(%r1)		/* 3rd argument */
  	STREG	%r25, TASK_PT_GR25(%r1)		/* 2nd argument */
  	STREG	%r26, TASK_PT_GR26(%r1)	 	/* 1st argument */
  	STREG	%r27, TASK_PT_GR27(%r1)		/* user dp */
  	STREG   %r28, TASK_PT_GR28(%r1)         /* return value 0 */
  	STREG   %r0, TASK_PT_ORIG_R28(%r1)     /* don't prohibit restarts */
  	STREG   %r29, TASK_PT_GR29(%r1)         /* 8th argument */
  	STREG	%r31, TASK_PT_GR31(%r1)		/* preserve syscall return ptr */
  	
  	ldo	TASK_PT_FR0(%r1), %r27		/* save fpregs from the kernel */
  	save_fp	%r27				/* or potential task switch  */
  
  	mfctl	%cr11, %r27			/* i.e. SAR */
  	STREG	%r27, TASK_PT_SAR(%r1)
  
  	loadgp
  
  	stw	%r21, -52(%r30)			;! 5th argument
  	stw	%r20, -56(%r30)			;! 6th argument
  	stw	%r19, -60(%r30)			;! 7th argument
  	stw     %r29, -64(%r30)                 ;! 8th argument
  
  	ldil	L%hpux_call_table, %r21
  	ldo	R%hpux_call_table(%r21), %r21
  	comiclr,>>=	__NR_HPUX_syscalls, %r22, %r0
  	b,n	syscall_nosys
  	LDREGX	%r22(%r21), %r21
  	ldil	L%hpux_syscall_exit,%r2
  	be	0(%sr7,%r21)
  	ldo	R%hpux_syscall_exit(%r2),%r2
  
  syscall_nosys:
  	ldil	L%hpux_syscall_exit,%r1
  	be	R%hpux_syscall_exit(%sr7,%r1)
  	ldo	-ENOSYS(%r0),%r28
  ENDPROC(hpux_gateway_page)
  
  	.align	PAGE_SIZE
  ENTRY(end_hpux_gateway_page)