1/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1995, 96, 97, 98, 99, 2000, 01 by Ralf Baechle
7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
8 * Copyright (C) 2001 MIPS Technologies, Inc.
9 */
10#include <linux/errno.h>
11#include <asm/asm.h>
12#include <asm/asmmacro.h>
13#include <asm/irqflags.h>
14#include <asm/mipsregs.h>
15#include <asm/regdef.h>
16#include <asm/stackframe.h>
17#include <asm/thread_info.h>
18#include <asm/unistd.h>
19
20#ifndef CONFIG_MIPS32_O32
21/* No O32, so define handle_sys here */
22#define handle_sysn32 handle_sys
23#endif
24
25 .align 5
26NESTED(handle_sysn32, PT_SIZE, sp)
27#ifndef CONFIG_MIPS32_O32
28 .set noat
29 SAVE_SOME
30 TRACE_IRQS_ON_RELOAD
31 STI
32 .set at
33#endif
34
35 dsubu t0, v0, __NR_N32_Linux # check syscall number
36 sltiu t0, t0, __NR_N32_Linux_syscalls
37
38#ifndef CONFIG_MIPS32_O32
39 ld t1, PT_EPC(sp) # skip syscall on return
40 daddiu t1, 4 # skip to next instruction
41 sd t1, PT_EPC(sp)
42#endif
43 beqz t0, not_n32_scall
44
45 sd a3, PT_R26(sp) # save a3 for syscall restarting
46
47 LONG_S v0, TI_SYSCALL($28) # Store syscall number
48
49 li t1, _TIF_WORK_SYSCALL_ENTRY
50 LONG_L t0, TI_FLAGS($28) # syscall tracing enabled?
51 and t0, t1, t0
52 bnez t0, n32_syscall_trace_entry
53
54syscall_common:
55 dsll t0, v0, 3 # offset into table
56 ld t2, (sysn32_call_table - (__NR_N32_Linux * 8))(t0)
57
58 jalr t2 # Do The Real Thing (TM)
59
60 li t0, -EMAXERRNO - 1 # error?
61 sltu t0, t0, v0
62 sd t0, PT_R7(sp) # set error flag
63 beqz t0, 1f
64
65 ld t1, PT_R2(sp) # syscall number
66 dnegu v0 # error
67 sd t1, PT_R0(sp) # save it for syscall restarting
681: sd v0, PT_R2(sp) # result
69
70 j syscall_exit_partial
71
72/* ------------------------------------------------------------------------ */
73
74n32_syscall_trace_entry:
75 SAVE_STATIC
76 move a0, sp
77 jal syscall_trace_enter
78
79 bltz v0, 1f # seccomp failed? Skip syscall
80
81 RESTORE_STATIC
82 ld v0, PT_R2(sp) # Restore syscall (maybe modified)
83 ld a0, PT_R4(sp) # Restore argument registers
84 ld a1, PT_R5(sp)
85 ld a2, PT_R6(sp)
86 ld a3, PT_R7(sp)
87 ld a4, PT_R8(sp)
88 ld a5, PT_R9(sp)
89
90 dsubu t2, v0, __NR_N32_Linux # check (new) syscall number
91 sltiu t0, t2, __NR_N32_Linux_syscalls
92 beqz t0, not_n32_scall
93
94 j syscall_common
95
961: j syscall_exit
97
98not_n32_scall:
99 /* This is not an n32 compatibility syscall, pass it on to
100 the n64 syscall handlers. */
101 j handle_sys64
102
103 END(handle_sysn32)
104
105#define __SYSCALL(nr, entry) PTR_WD entry
106 .type sysn32_call_table, @object
107EXPORT(sysn32_call_table)
108#include <asm/syscall_table_n32.h>
109

source code of linux/arch/mips/kernel/scall64-n32.S