source: rtems/c/src/lib/libcpu/sparc64/shared/syscall/sparc64-syscall.S @ 71d97c9

4.115
Last change on this file since 71d97c9 was 71d97c9, checked in by Gedare Bloom <gedare@…>, on Dec 8, 2014 at 6:16:37 PM

sparc64: put each copyright on one line

  • Property mode set to 100644
File size: 3.6 KB
Line 
1/*
2 *  systrap.S
3 *
4 *  This file contains emulated system calls using software trap 0.
5 *  The following calls are supported:
6 *
7 *    + SYS_exit  (halt)
8 *    + SYS_irqdis  (disable interrupts)
9 *    + SYS_irqset  (set interrupt level)
10 *
11 *  COPYRIGHT (c) 1995. European Space Agency.
12 *  COPYRIGHT (c) 2010. Gedare Bloom.
13 *
14 *  This terms of the RTEMS license apply to this file.
15 *
16 */
17
18#include <rtems/asm.h>
19#include "sparc64-syscall.h"
20
21
22.seg    "text"
23/*
24 *  system call
25 *
26 *  On entry:
27 *      g4[AG | GL=1] = tstate (from trap table)
28 *      g2[AG | GL=1] = trap vector # (256)
29 *      g3[AG | GL=1] = address of SYM(syscall)
30 *      g4[AG | GL-1] = system call id
31 *    if arch = sun4v:
32 *      We need to back to GL-1 to read the system call id.
33 *   on sun4u:
34 *      We need to go back to the normal globals to read the system call id.
35 *   
36 *    First thing is to return to the previous set of globals, so
37 *    that the system call id can be read.  The syscall code needs
38 *    to re-read tstate.
39 *
40 *    syscall should only ever be entered by ta 0 being called explicitly
41 *    by a function that knows what is happening.  This means the syscall
42 *    code can safely use any scratch registers and the %o registers.
43 */
44
45
46PUBLIC(syscall)
47
48 
49  SYM(syscall):
50    mov   %g0, %g4  ! clear %g4 at this GL
51#if defined (SUN4U)
52    rdpr  %pstate, %g1
53    andn  %g1, SPARC_PSTATE_AG_MASK, %g1
54    wrpr  %g1, %g0, %pstate                 ! go to regular globals
55#elif defined (SUN4V)
56    rdpr  %gl, %g1
57    dec   %g1
58    wrpr  %g0, %g1, %gl                     ! go back to GL = GL - 1
59#endif
60
61    subcc %g4, 2, %g0                     
62    bne   3f
63    rdpr  %tstate, %g5                      ! re-read tstate, use delay slot
64
65    ! syscall 2, disable interrupts
66    rdpr  %pil, %g1
67    and   %g5, SPARC_TSTATE_IE_MASK, %o0
68    or    %o0, %g1, %o0                     ! return TSTATE_IE | PIL
69    wrpr  %g0, 0xf, %pil                    ! set PIL to 15
70    andn  %g5, SPARC_TSTATE_IE_MASK, %g1
71    wrpr  %g0, %g1, %tstate                 ! disable interrupts in trap state
72    ba,a  9f
73
74    3:  ! syscall 3, enable interrupts
75    subcc %g4, 3, %g0                     
76    bne   1f
77    and   %o0, 0xf, %g1
78    wrpr  %g0, %g1, %pil                    ! restore PIL
79!    and   %o0, SPARC_TSTATE_IE_MASK, %g1
80!    or    %g5, %g1, %g1                     ! restore saved IE
81    or    %g5, SPARC_TSTATE_IE_MASK, %g1    ! restore IE (safe?)
82    wrpr  %g0, %g1, %tstate     
83    ba,a  9f
84
85    1:         
86    ba,a  1b                                ! spin. taking a trap here -> htrap
87
88    9:                                      ! leave
89    mov  0, %g4                             ! clear %g4
90    DONE
91
92PUBLIC(sparc_disable_interrupts)
93
94  SYM(sparc_disable_interrupts):
95    mov  SYS_irqdis, %g4
96    ta  0
97#if 0
98    rdpr  %pstate, %g5
99    rdpr  %pil, %g1
100    and   %g5, SPARC_PSTATE_IE_MASK, %o0
101    or    %o0, %g1, %o0                     ! return PSTATE_IE | PIL
102    wrpr  %g0, 0xf, %pil                    ! set PIL to 15
103    andn  %g5, SPARC_PSTATE_IE_MASK, %g1
104    wrpr  %g0, %g1, %pstate                 ! disable interrupts
105#endif
106    retl 
107    nop
108
109PUBLIC(sparc_enable_interrupts)
110
111  SYM(sparc_enable_interrupts):
112    mov  SYS_irqen, %g4
113    ta  0
114#if 0
115    rdpr  %pstate, %g5
116    and   %o0, 0xf, %g1
117    wrpr  %g0, %g1, %pil                    ! restore PIL
118    and   %o0, SPARC_PSTATE_IE_MASK, %g1
119    or    %g5, %g1, %g1                     ! restore saved IE
120!    or    %g5, SPARC_PSTATE_IE_MASK, %g1    ! set IE regardless of old (safe?)
121    wrpr  %g0, %g1, %pstate
122#endif
123    retl 
124    nop
125
126    /* end of file */
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