xref: /linux/arch/mips/kernel/scall64-n32.S (revision 5c1672705a1a2389f5ad78e0fea6f08ed32d6f18)
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