xref: /linux/arch/mips/kernel/scall64-n64.S (revision 8e07e0e3964ca4e23ce7b68e2096fe660a888942)
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