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, 02 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/asm-offsets.h>
18#include <asm/sysmips.h>
19#include <asm/thread_info.h>
20#include <asm/unistd.h>
21
22#ifndef CONFIG_MIPS32_COMPAT
23/* Neither O32 nor N32, so define handle_sys here */
24#define handle_sys64 handle_sys
25#endif
26
27 .align 5
28NESTED(handle_sys64, PT_SIZE, sp)
29#if !defined(CONFIG_MIPS32_O32) && !defined(CONFIG_MIPS32_N32)
30 /*
31 * When 32-bit compatibility is configured scall_o32.S
32 * already did this.
33 */
34 .set noat
35 SAVE_SOME
36 TRACE_IRQS_ON_RELOAD
37 STI
38 .set at
39#endif
40
41#if !defined(CONFIG_MIPS32_O32) && !defined(CONFIG_MIPS32_N32)
42 ld t1, PT_EPC(sp) # skip syscall on return
43 daddiu t1, 4 # skip to next instruction
44 sd t1, PT_EPC(sp)
45#endif
46
47 sd a3, PT_R26(sp) # save a3 for syscall restarting
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, syscall_trace_entry
53
54syscall_common:
55 dsubu t2, v0, __NR_64_Linux
56 sltiu t0, t2, __NR_64_Linux_syscalls
57 beqz t0, illegal_syscall
58
59 dsll t0, t2, 3 # offset into table
60 dla t2, sys_call_table
61 daddu t0, t2, t0
62 ld t2, (t0) # syscall routine
63 beqz t2, illegal_syscall
64
65 jalr t2 # Do The Real Thing (TM)
66
67 li t0, -EMAXERRNO - 1 # error?
68 sltu t0, t0, v0
69 sd t0, PT_R7(sp) # set error flag
70 beqz t0, 1f
71
72 ld t1, PT_R2(sp) # syscall number
73 dnegu v0 # error
74 sd t1, PT_R0(sp) # save it for syscall restarting
751: sd v0, PT_R2(sp) # result
76
77n64_syscall_exit:
78 j syscall_exit_partial
79
80/* ------------------------------------------------------------------------ */
81
82syscall_trace_entry:
83 SAVE_STATIC
84 move a0, sp
85 move a1, v0
86 jal syscall_trace_enter
87
88 bltz v0, 1f # seccomp failed? Skip syscall
89
90 RESTORE_STATIC
91 ld v0, PT_R2(sp) # Restore syscall (maybe modified)
92 ld a0, PT_R4(sp) # Restore argument registers
93 ld a1, PT_R5(sp)
94 ld a2, PT_R6(sp)
95 ld a3, PT_R7(sp)
96 ld a4, PT_R8(sp)
97 ld a5, PT_R9(sp)
98 j syscall_common
99
1001: j syscall_exit
101
102illegal_syscall:
103 /* This also isn't a 64-bit syscall, throw an error. */
104 li v0, ENOSYS # error
105 sd v0, PT_R2(sp)
106 li t0, 1 # set error flag
107 sd t0, PT_R7(sp)
108 j n64_syscall_exit
109 END(handle_sys64)
110
111#define __SYSCALL(nr, entry) PTR_WD entry
112 .align 3
113 .type sys_call_table, @object
114EXPORT(sys_call_table)
115#include <asm/syscall_table_n64.h>
116

source code of linux/arch/mips/kernel/scall64-n64.S