[linux-2.6-block.git] / arch / parisc / hpux / gate.S

/*
 *
 * 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)
Commit	Line	Data
1da177e4 LT	1	/*
	2	*
	3	* Linux/PARISC Project (http://www.parisc-linux.org/)
	4	*
	5	* System call entry code Copyright (c) Matthew Wilcox 1999 <willy@bofh.ai>
	6	* Licensed under the GNU GPL.
	7	* thanks to Philipp Rumpf, Mike Shaver and various others
	8	* sorry about the wall, puffin..
	9	*/
	10
	11	#include <asm/assembly.h>
0013a854	12	#include <asm/asm-offsets.h>
1da177e4 LT	13	#include <asm/unistd.h>
1da177e4 LT	14	#include <asm/errno.h>
79793455	15	#include <linux/linkage.h>
1da177e4	16
79793455	17	.level LEVEL
dfcf753b	18	.text
1da177e4	19
1da177e4 LT	20	.import hpux_call_table
1da177e4 LT	21	.import hpux_syscall_exit,code
1da177e4	22
873d50e2	23	.align PAGE_SIZE
79793455	24	ENTRY(hpux_gateway_page)
1da177e4	25	nop
79793455	26	#ifdef CONFIG_64BIT
1da177e4 LT	27	#warning NEEDS WORK for 64-bit
	28	#endif
	29	ldw -64(%r30), %r29 ;! 8th argument
	30	ldw -60(%r30), %r19 ;! 7th argument
	31	ldw -56(%r30), %r20 ;! 6th argument
	32	ldw -52(%r30), %r21 ;! 5th argument
	33	gate .+8, %r0 /* become privileged */
	34	mtsp %r0,%sr4 /* get kernel space into sr4 */
	35	mtsp %r0,%sr5 /* get kernel space into sr5 */
	36	mtsp %r0,%sr6 /* get kernel space into sr6 */
	37	mfsp %sr7,%r1 /* save user sr7 */
	38	mtsp %r1,%sr3 /* and store it in sr3 */
	39
	40	mtctl %r30,%cr28
	41	mfctl %cr30,%r1
	42	xor %r1,%r30,%r30 /* ye olde xor trick */
	43	xor %r1,%r30,%r1
	44	xor %r1,%r30,%r30
	45	ldo TASK_SZ_ALGN+FRAME_SIZE(%r30),%r30 /* set up kernel stack */
	46
	47	/* N.B.: It is critical that we don't set sr7 to 0 until r30
	48	* contains a valid kernel stack pointer. It is also
	49	* critical that we don't start using the kernel stack
	50	* until after sr7 has been set to 0.
	51	*/
	52
	53	mtsp %r0,%sr7 /* get kernel space into sr7 */
	54	STREG %r1,TASK_PT_GR30-TASK_SZ_ALGN-FRAME_SIZE(%r30) /* save usp */
	55	ldo -TASK_SZ_ALGN-FRAME_SIZE(%r30),%r1 /* get task ptr in %r1 */
	56
	57	/* Save some registers for sigcontext and potential task
	58	switch (see entry.S for the details of which ones are
	59	saved/restored). TASK_PT_PSW is zeroed so we can see whether
	60	a process is on a syscall or not. For an interrupt the real
	61	PSW value is stored. This is needed for gdb and sys_ptrace. */
	62	STREG %r0, TASK_PT_PSW(%r1)
	63	STREG %r2, TASK_PT_GR2(%r1) /* preserve rp */
	64	STREG %r19, TASK_PT_GR19(%r1) /* 7th argument */
	65	STREG %r20, TASK_PT_GR20(%r1) /* 6th argument */
	66	STREG %r21, TASK_PT_GR21(%r1) /* 5th argument */
	67	STREG %r22, TASK_PT_GR22(%r1) /* syscall # */
	68	STREG %r23, TASK_PT_GR23(%r1) /* 4th argument */
	69	STREG %r24, TASK_PT_GR24(%r1) /* 3rd argument */
	70	STREG %r25, TASK_PT_GR25(%r1) /* 2nd argument */
	71	STREG %r26, TASK_PT_GR26(%r1) /* 1st argument */
	72	STREG %r27, TASK_PT_GR27(%r1) /* user dp */
	73	STREG %r28, TASK_PT_GR28(%r1) /* return value 0 */
00df111e	74	STREG %r0, TASK_PT_ORIG_R28(%r1) /* don't prohibit restarts */
1da177e4 LT	75	STREG %r29, TASK_PT_GR29(%r1) /* 8th argument */
	76	STREG %r31, TASK_PT_GR31(%r1) /* preserve syscall return ptr */
	77
	78	ldo TASK_PT_FR0(%r1), %r27 /* save fpregs from the kernel */
	79	save_fp %r27 /* or potential task switch */
	80
	81	mfctl %cr11, %r27 /* i.e. SAR */
	82	STREG %r27, TASK_PT_SAR(%r1)
	83
	84	loadgp
	85
	86	stw %r21, -52(%r30) ;! 5th argument
	87	stw %r20, -56(%r30) ;! 6th argument
	88	stw %r19, -60(%r30) ;! 7th argument
	89	stw %r29, -64(%r30) ;! 8th argument
	90
	91	ldil L%hpux_call_table, %r21
	92	ldo R%hpux_call_table(%r21), %r21
	93	comiclr,>>= __NR_HPUX_syscalls, %r22, %r0
	94	b,n syscall_nosys
79793455	95	LDREGX %r22(%r21), %r21
1da177e4 LT	96	ldil L%hpux_syscall_exit,%r2
	97	be 0(%sr7,%r21)
	98	ldo R%hpux_syscall_exit(%r2),%r2
	99
	100	syscall_nosys:
	101	ldil L%hpux_syscall_exit,%r1
	102	be R%hpux_syscall_exit(%sr7,%r1)
	103	ldo -ENOSYS(%r0),%r28
79793455	104	ENDPROC(hpux_gateway_page)
1da177e4	105
873d50e2	106	.align PAGE_SIZE
79793455	107	ENTRY(end_hpux_gateway_page)