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 LONG_S v0, TI_SYSCALL($28) # Store syscall number
50
51 li t1, _TIF_WORK_SYSCALL_ENTRY
52 LONG_L t0, TI_FLAGS($28) # syscall tracing enabled?
53 and t0, t1, t0
54 bnez t0, syscall_trace_entry
55
56syscall_common:
57 dsubu t2, v0, __NR_64_Linux
58 sltiu t0, t2, __NR_64_Linux_syscalls
59 beqz t0, illegal_syscall
60
61 dsll t0, t2, 3 # offset into table
62 dla t2, sys_call_table
63 daddu t0, t2, t0
64 ld t2, (t0) # syscall routine
65 beqz t2, illegal_syscall
66
67 jalr t2 # Do The Real Thing (TM)
68
69 li t0, -EMAXERRNO - 1 # error?
70 sltu t0, t0, v0
71 sd t0, PT_R7(sp) # set error flag
72 beqz t0, 1f
73
74 ld t1, PT_R2(sp) # syscall number
75 dnegu v0 # error
76 sd t1, PT_R0(sp) # save it for syscall restarting
771: sd v0, PT_R2(sp) # result
78
79n64_syscall_exit:
80 j syscall_exit_partial
81
82/* ------------------------------------------------------------------------ */
83
84syscall_trace_entry:
85 SAVE_STATIC
86 move a0, sp
87 jal syscall_trace_enter
88
89 bltz v0, 1f # seccomp failed? Skip syscall
90
91 RESTORE_STATIC
92 ld v0, PT_R2(sp) # Restore syscall (maybe modified)
93 ld a0, PT_R4(sp) # Restore argument registers
94 ld a1, PT_R5(sp)
95 ld a2, PT_R6(sp)
96 ld a3, PT_R7(sp)
97 ld a4, PT_R8(sp)
98 ld a5, PT_R9(sp)
99 j syscall_common
100
1011: j syscall_exit
102
103illegal_syscall:
104 /* This also isn't a 64-bit syscall, throw an error. */
105 li v0, ENOSYS # error
106 sd v0, PT_R2(sp)
107 li t0, 1 # set error flag
108 sd t0, PT_R7(sp)
109 j n64_syscall_exit
110 END(handle_sys64)
111
112#define __SYSCALL(nr, entry) PTR_WD entry
113 .align 3
114 .type sys_call_table, @object
115EXPORT(sys_call_table)
116#include <asm/syscall_table_n64.h>
117

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