linux/arch/sparc/kernel/syscalls.S
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   1        /* SunOS's execv() call only specifies the argv argument, the
   2         * environment settings are the same as the calling processes.
   3         */
   4sys_execve:
   5        sethi   %hi(sparc_execve), %g1
   6        ba,pt   %xcc, execve_merge
   7         or     %g1, %lo(sparc_execve), %g1
   8
   9#ifdef CONFIG_COMPAT
  10sunos_execv:
  11        stx     %g0, [%sp + PTREGS_OFF + PT_V9_I2]
  12sys32_execve:
  13        sethi   %hi(sparc32_execve), %g1
  14        or      %g1, %lo(sparc32_execve), %g1
  15#endif
  16
  17execve_merge:
  18        flushw
  19        jmpl    %g1, %g0
  20         add    %sp, PTREGS_OFF, %o0
  21
  22        .align  32
  23sys_sparc_pipe:
  24        ba,pt   %xcc, sys_sparc_pipe_real
  25         add    %sp, PTREGS_OFF, %o0
  26sys_nis_syscall:
  27        ba,pt   %xcc, c_sys_nis_syscall
  28         add    %sp, PTREGS_OFF, %o0
  29sys_memory_ordering:
  30        ba,pt   %xcc, sparc_memory_ordering
  31         add    %sp, PTREGS_OFF, %o1
  32sys_sigaltstack:
  33        ba,pt   %xcc, do_sigaltstack
  34         add    %i6, STACK_BIAS, %o2
  35#ifdef CONFIG_COMPAT
  36sys32_sigstack:
  37        ba,pt   %xcc, do_sys32_sigstack
  38         mov    %i6, %o2
  39sys32_sigaltstack:
  40        ba,pt   %xcc, do_sys32_sigaltstack
  41         mov    %i6, %o2
  42#endif
  43        .align  32
  44#ifdef CONFIG_COMPAT
  45sys32_sigreturn:
  46        add     %sp, PTREGS_OFF, %o0
  47        call    do_sigreturn32
  48         add    %o7, 1f-.-4, %o7
  49        nop
  50#endif
  51sys_rt_sigreturn:
  52        add     %sp, PTREGS_OFF, %o0
  53        call    do_rt_sigreturn
  54         add    %o7, 1f-.-4, %o7
  55        nop
  56#ifdef CONFIG_COMPAT
  57sys32_rt_sigreturn:
  58        add     %sp, PTREGS_OFF, %o0
  59        call    do_rt_sigreturn32
  60         add    %o7, 1f-.-4, %o7
  61        nop
  62#endif
  63        .align  32
  641:      ldx     [%g6 + TI_FLAGS], %l5
  65        andcc   %l5, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT), %g0
  66        be,pt   %icc, rtrap
  67         nop
  68        call    syscall_trace_leave
  69         add    %sp, PTREGS_OFF, %o0
  70        ba,pt   %xcc, rtrap
  71         nop
  72
  73        /* This is how fork() was meant to be done, 8 instruction entry.
  74         *
  75         * I questioned the following code briefly, let me clear things
  76         * up so you must not reason on it like I did.
  77         *
  78         * Know the fork_kpsr etc. we use in the sparc32 port?  We don't
  79         * need it here because the only piece of window state we copy to
  80         * the child is the CWP register.  Even if the parent sleeps,
  81         * we are safe because we stuck it into pt_regs of the parent
  82         * so it will not change.
  83         *
  84         * XXX This raises the question, whether we can do the same on
  85         * XXX sparc32 to get rid of fork_kpsr _and_ fork_kwim.  The
  86         * XXX answer is yes.  We stick fork_kpsr in UREG_G0 and
  87         * XXX fork_kwim in UREG_G1 (global registers are considered
  88         * XXX volatile across a system call in the sparc ABI I think
  89         * XXX if it isn't we can use regs->y instead, anyone who depends
  90         * XXX upon the Y register being preserved across a fork deserves
  91         * XXX to lose).
  92         *
  93         * In fact we should take advantage of that fact for other things
  94         * during system calls...
  95         */
  96        .align  32
  97sys_vfork: /* Under Linux, vfork and fork are just special cases of clone. */
  98        sethi   %hi(0x4000 | 0x0100 | SIGCHLD), %o0
  99        or      %o0, %lo(0x4000 | 0x0100 | SIGCHLD), %o0
 100        ba,pt   %xcc, sys_clone
 101sys_fork:
 102         clr    %o1
 103        mov     SIGCHLD, %o0
 104sys_clone:
 105        flushw
 106        movrz   %o1, %fp, %o1
 107        mov     0, %o3
 108        ba,pt   %xcc, sparc_do_fork
 109         add    %sp, PTREGS_OFF, %o2
 110
 111        .globl  ret_from_syscall
 112ret_from_syscall:
 113        /* Clear current_thread_info()->new_child, and
 114         * check performance counter stuff too.
 115         */
 116        stb     %g0, [%g6 + TI_NEW_CHILD]
 117        ldx     [%g6 + TI_FLAGS], %l0
 118        call    schedule_tail
 119         mov    %g7, %o0
 120        andcc   %l0, _TIF_PERFCTR, %g0
 121        be,pt   %icc, 1f
 122         nop
 123        ldx     [%g6 + TI_PCR], %o7
 124        wr      %g0, %o7, %pcr
 125
 126        /* Blackbird errata workaround.  See commentary in
 127         * smp.c:smp_percpu_timer_interrupt() for more
 128         * information.
 129         */
 130        ba,pt   %xcc, 99f
 131         nop
 132
 133        .align  64
 13499:     wr      %g0, %g0, %pic
 135        rd      %pic, %g0
 136
 1371:      ba,pt   %xcc, ret_sys_call
 138         ldx    [%sp + PTREGS_OFF + PT_V9_I0], %o0
 139
 140        .globl  sparc_exit
 141        .type   sparc_exit,#function
 142sparc_exit:
 143        rdpr    %pstate, %g2
 144        wrpr    %g2, PSTATE_IE, %pstate
 145        rdpr    %otherwin, %g1
 146        rdpr    %cansave, %g3
 147        add     %g3, %g1, %g3
 148        wrpr    %g3, 0x0, %cansave
 149        wrpr    %g0, 0x0, %otherwin
 150        wrpr    %g2, 0x0, %pstate
 151        ba,pt   %xcc, sys_exit
 152         stb    %g0, [%g6 + TI_WSAVED]
 153        .size   sparc_exit,.-sparc_exit
 154
 155linux_sparc_ni_syscall:
 156        sethi   %hi(sys_ni_syscall), %l7
 157        ba,pt   %xcc, 4f
 158         or     %l7, %lo(sys_ni_syscall), %l7
 159
 160linux_syscall_trace32:
 161        call    syscall_trace_enter
 162         add    %sp, PTREGS_OFF, %o0
 163        brnz,pn %o0, 3f
 164         mov    -ENOSYS, %o0
 165        srl     %i0, 0, %o0
 166        srl     %i4, 0, %o4
 167        srl     %i1, 0, %o1
 168        srl     %i2, 0, %o2
 169        ba,pt   %xcc, 2f
 170         srl    %i3, 0, %o3
 171
 172linux_syscall_trace:
 173        call    syscall_trace_enter
 174         add    %sp, PTREGS_OFF, %o0
 175        brnz,pn %o0, 3f
 176         mov    -ENOSYS, %o0
 177        mov     %i0, %o0
 178        mov     %i1, %o1
 179        mov     %i2, %o2
 180        mov     %i3, %o3
 181        b,pt    %xcc, 2f
 182         mov    %i4, %o4
 183
 184
 185        /* Linux 32-bit system calls enter here... */
 186        .align  32
 187        .globl  linux_sparc_syscall32
 188linux_sparc_syscall32:
 189        /* Direct access to user regs, much faster. */
 190        cmp     %g1, NR_SYSCALLS                        ! IEU1  Group
 191        bgeu,pn %xcc, linux_sparc_ni_syscall            ! CTI
 192         srl    %i0, 0, %o0                             ! IEU0
 193        sll     %g1, 2, %l4                             ! IEU0  Group
 194        srl     %i4, 0, %o4                             ! IEU1
 195        lduw    [%l7 + %l4], %l7                        ! Load
 196        srl     %i1, 0, %o1                             ! IEU0  Group
 197        ldx     [%g6 + TI_FLAGS], %l0           ! Load
 198
 199        srl     %i5, 0, %o5                             ! IEU1
 200        srl     %i2, 0, %o2                             ! IEU0  Group
 201        andcc   %l0, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT), %g0
 202        bne,pn  %icc, linux_syscall_trace32             ! CTI
 203         mov    %i0, %l5                                ! IEU1
 204        call    %l7                                     ! CTI   Group brk forced
 205         srl    %i3, 0, %o3                             ! IEU0
 206        ba,a,pt %xcc, 3f
 207
 208        /* Linux native system calls enter here... */
 209        .align  32
 210        .globl  linux_sparc_syscall
 211linux_sparc_syscall:
 212        /* Direct access to user regs, much faster. */
 213        cmp     %g1, NR_SYSCALLS                        ! IEU1  Group
 214        bgeu,pn %xcc, linux_sparc_ni_syscall            ! CTI
 215         mov    %i0, %o0                                ! IEU0
 216        sll     %g1, 2, %l4                             ! IEU0  Group
 217        mov     %i1, %o1                                ! IEU1
 218        lduw    [%l7 + %l4], %l7                        ! Load
 2194:      mov     %i2, %o2                                ! IEU0  Group
 220        ldx     [%g6 + TI_FLAGS], %l0           ! Load
 221
 222        mov     %i3, %o3                                ! IEU1
 223        mov     %i4, %o4                                ! IEU0  Group
 224        andcc   %l0, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT), %g0
 225        bne,pn  %icc, linux_syscall_trace               ! CTI   Group
 226         mov    %i0, %l5                                ! IEU0
 2272:      call    %l7                                     ! CTI   Group brk forced
 228         mov    %i5, %o5                                ! IEU0
 229        nop
 230
 2313:      stx     %o0, [%sp + PTREGS_OFF + PT_V9_I0]
 232ret_sys_call:
 233        ldx     [%sp + PTREGS_OFF + PT_V9_TSTATE], %g3
 234        ldx     [%sp + PTREGS_OFF + PT_V9_TNPC], %l1 ! pc = npc
 235        sra     %o0, 0, %o0
 236        mov     %ulo(TSTATE_XCARRY | TSTATE_ICARRY), %g2
 237        sllx    %g2, 32, %g2
 238
 239        /* Check if force_successful_syscall_return()
 240         * was invoked.
 241         */
 242        ldub    [%g6 + TI_SYS_NOERROR], %l2
 243        brnz,a,pn %l2, 80f
 244         stb    %g0, [%g6 + TI_SYS_NOERROR]
 245
 246        cmp     %o0, -ERESTART_RESTARTBLOCK
 247        bgeu,pn %xcc, 1f
 248         andcc  %l0, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT), %l6
 24980:
 250        /* System call success, clear Carry condition code. */
 251        andn    %g3, %g2, %g3
 252        stx     %g3, [%sp + PTREGS_OFF + PT_V9_TSTATE]  
 253        bne,pn  %icc, linux_syscall_trace2
 254         add    %l1, 0x4, %l2                   ! npc = npc+4
 255        stx     %l1, [%sp + PTREGS_OFF + PT_V9_TPC]
 256        ba,pt   %xcc, rtrap
 257         stx    %l2, [%sp + PTREGS_OFF + PT_V9_TNPC]
 258
 2591:
 260        /* System call failure, set Carry condition code.
 261         * Also, get abs(errno) to return to the process.
 262         */
 263        andcc   %l0, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT), %l6  
 264        sub     %g0, %o0, %o0
 265        or      %g3, %g2, %g3
 266        stx     %o0, [%sp + PTREGS_OFF + PT_V9_I0]
 267        stx     %g3, [%sp + PTREGS_OFF + PT_V9_TSTATE]
 268        bne,pn  %icc, linux_syscall_trace2
 269         add    %l1, 0x4, %l2                   ! npc = npc+4
 270        stx     %l1, [%sp + PTREGS_OFF + PT_V9_TPC]
 271
 272        b,pt    %xcc, rtrap
 273         stx    %l2, [%sp + PTREGS_OFF + PT_V9_TNPC]
 274linux_syscall_trace2:
 275        call    syscall_trace_leave
 276         add    %sp, PTREGS_OFF, %o0
 277        stx     %l1, [%sp + PTREGS_OFF + PT_V9_TPC]
 278        ba,pt   %xcc, rtrap
 279         stx    %l2, [%sp + PTREGS_OFF + PT_V9_TNPC]
 280
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