gate.S
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/*
*
* 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 %r28, TASK_PT_ORIG_R28(%r1) /* return value 0 (saved for signals) */
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)