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 li t1, _TIF_WORK_SYSCALL_ENTRY
48 LONG_L t0, TI_FLAGS($28) # syscall tracing enabled?
49 and t0, t1, t0
50 bnez t0, n32_syscall_trace_entry
51
52syscall_common:
53 dsll t0, v0, 3 # offset into table
54 ld t2, (sysn32_call_table - (__NR_N32_Linux * 8))(t0)
55
56 jalr t2 # Do The Real Thing (TM)
57
58 li t0, -EMAXERRNO - 1 # error?
59 sltu t0, t0, v0
60 sd t0, PT_R7(sp) # set error flag
61 beqz t0, 1f
62
63 ld t1, PT_R2(sp) # syscall number
64 dnegu v0 # error
65 sd t1, PT_R0(sp) # save it for syscall restarting
661: sd v0, PT_R2(sp) # result
67
68 j syscall_exit_partial
69
70/* ------------------------------------------------------------------------ */
71
72n32_syscall_trace_entry:
73 SAVE_STATIC
74 move a0, sp
75 move a1, v0
76 jal syscall_trace_enter
77
78 bltz v0, 1f # seccomp failed? Skip syscall
79
80 RESTORE_STATIC
81 ld v0, PT_R2(sp) # Restore syscall (maybe modified)
82 ld a0, PT_R4(sp) # Restore argument registers
83 ld a1, PT_R5(sp)
84 ld a2, PT_R6(sp)
85 ld a3, PT_R7(sp)
86 ld a4, PT_R8(sp)
87 ld a5, PT_R9(sp)
88
89 dsubu t2, v0, __NR_N32_Linux # check (new) syscall number
90 sltiu t0, t2, __NR_N32_Linux_syscalls
91 beqz t0, not_n32_scall
92
93 j syscall_common
94
951: j syscall_exit
96
97not_n32_scall:
98 /* This is not an n32 compatibility syscall, pass it on to
99 the n64 syscall handlers. */
100 j handle_sys64
101
102 END(handle_sysn32)
103
104#define __SYSCALL(nr, entry) PTR_WD entry
105 .type sysn32_call_table, @object
106EXPORT(sysn32_call_table)
107#include <asm/syscall_table_n32.h>
108

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