Subversion Repositories or1k_soc_on_altera_embedded_dev_kit

/*
 *
 * 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)