xref: /openbmc/linux/arch/sparc/kernel/syscalls.S (revision feac8c8b) 
1/* SPDX-License-Identifier: GPL-2.0 */
2	/* SunOS's execv() call only specifies the argv argument, the
3	 * environment settings are the same as the calling processes.
4	 */
5sys64_execve:
6	set	sys_execve, %g1
7	jmpl	%g1, %g0
8	 flushw
9
10sys64_execveat:
11	set	sys_execveat, %g1
12	jmpl	%g1, %g0
13	 flushw
14
15#ifdef CONFIG_COMPAT
16sunos_execv:
17	mov	%g0, %o2
18sys32_execve:
19	set	compat_sys_execve, %g1
20	jmpl	%g1, %g0
21	 flushw
22
23sys32_execveat:
24	set	compat_sys_execveat, %g1
25	jmpl	%g1, %g0
26	 flushw
27#endif
28
29	.align	32
30sys_sparc_pipe:
31	ba,pt	%xcc, sys_sparc_pipe_real
32	 add	%sp, PTREGS_OFF, %o0
33sys_nis_syscall:
34	ba,pt	%xcc, c_sys_nis_syscall
35	 add	%sp, PTREGS_OFF, %o0
36sys_memory_ordering:
37	ba,pt	%xcc, sparc_memory_ordering
38	 add	%sp, PTREGS_OFF, %o1
39#ifdef CONFIG_COMPAT
40sys32_sigstack:
41	ba,pt	%xcc, do_sys32_sigstack
42	 mov	%i6, %o2
43#endif
44	.align	32
45#ifdef CONFIG_COMPAT
46sys32_sigreturn:
47	add	%sp, PTREGS_OFF, %o0
48	call	do_sigreturn32
49	 add	%o7, 1f-.-4, %o7
50	nop
51#endif
52sys_rt_sigreturn:
53	add	%sp, PTREGS_OFF, %o0
54	call	do_rt_sigreturn
55	 add	%o7, 1f-.-4, %o7
56	nop
57#ifdef CONFIG_COMPAT
58sys32_rt_sigreturn:
59	add	%sp, PTREGS_OFF, %o0
60	call	do_rt_sigreturn32
61	 add	%o7, 1f-.-4, %o7
62	nop
63#endif
64	.align	32
651:	ldx	[%g6 + TI_FLAGS], %l5
66	andcc	%l5, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT|_TIF_SYSCALL_TRACEPOINT|_TIF_NOHZ), %g0
67	be,pt	%icc, rtrap
68	 nop
69	call	syscall_trace_leave
70	 add	%sp, PTREGS_OFF, %o0
71	ba,pt	%xcc, rtrap
72	 nop
73
74	/* This is how fork() was meant to be done, 8 instruction entry.
75	 *
76	 * I questioned the following code briefly, let me clear things
77	 * up so you must not reason on it like I did.
78	 *
79	 * Know the fork_kpsr etc. we use in the sparc32 port?  We don't
80	 * need it here because the only piece of window state we copy to
81	 * the child is the CWP register.  Even if the parent sleeps,
82	 * we are safe because we stuck it into pt_regs of the parent
83	 * so it will not change.
84	 *
85	 * XXX This raises the question, whether we can do the same on
86	 * XXX sparc32 to get rid of fork_kpsr _and_ fork_kwim.  The
87	 * XXX answer is yes.  We stick fork_kpsr in UREG_G0 and
88	 * XXX fork_kwim in UREG_G1 (global registers are considered
89	 * XXX volatile across a system call in the sparc ABI I think
90	 * XXX if it isn't we can use regs->y instead, anyone who depends
91	 * XXX upon the Y register being preserved across a fork deserves
92	 * XXX to lose).
93	 *
94	 * In fact we should take advantage of that fact for other things
95	 * during system calls...
96	 */
97	.align	32
98sys_vfork: /* Under Linux, vfork and fork are just special cases of clone. */
99	sethi	%hi(0x4000 | 0x0100 | SIGCHLD), %o0
100	or	%o0, %lo(0x4000 | 0x0100 | SIGCHLD), %o0
101	ba,pt	%xcc, sys_clone
102sys_fork:
103	 clr	%o1
104	mov	SIGCHLD, %o0
105sys_clone:
106	flushw
107	movrz	%o1, %fp, %o1
108	mov	0, %o3
109	ba,pt	%xcc, sparc_do_fork
110	 add	%sp, PTREGS_OFF, %o2
111
112	.globl	ret_from_fork
113ret_from_fork:
114	/* Clear current_thread_info()->new_child. */
115	stb	%g0, [%g6 + TI_NEW_CHILD]
116	call	schedule_tail
117	 mov	%g7, %o0
118	ldx	[%sp + PTREGS_OFF + PT_V9_I0], %o0
119	brnz,pt	%o0, ret_sys_call
120	 ldx	[%g6 + TI_FLAGS], %l0
121	ldx	[%sp + PTREGS_OFF + PT_V9_G1], %l1
122	call	%l1
123	 ldx	[%sp + PTREGS_OFF + PT_V9_G2], %o0
124	ba,pt	%xcc, ret_sys_call
125	 mov	0, %o0
126
127	.globl	sparc_exit_group
128	.type	sparc_exit_group,#function
129sparc_exit_group:
130	sethi	%hi(sys_exit_group), %g7
131	ba,pt	%xcc, 1f
132	 or	%g7, %lo(sys_exit_group), %g7
133	.size	sparc_exit_group,.-sparc_exit_group
134
135	.globl	sparc_exit
136	.type	sparc_exit,#function
137sparc_exit:
138	sethi	%hi(sys_exit), %g7
139	or	%g7, %lo(sys_exit), %g7
1401:	rdpr	%pstate, %g2
141	wrpr	%g2, PSTATE_IE, %pstate
142	rdpr	%otherwin, %g1
143	rdpr	%cansave, %g3
144	add	%g3, %g1, %g3
145	wrpr	%g3, 0x0, %cansave
146	wrpr	%g0, 0x0, %otherwin
147	wrpr	%g2, 0x0, %pstate
148	jmpl	%g7, %g0
149	 stb	%g0, [%g6 + TI_WSAVED]
150	.size	sparc_exit,.-sparc_exit
151
152linux_sparc_ni_syscall:
153	sethi	%hi(sys_ni_syscall), %l7
154	ba,pt	%xcc, 4f
155	 or	%l7, %lo(sys_ni_syscall), %l7
156
157linux_syscall_trace32:
158	call	syscall_trace_enter
159	 add	%sp, PTREGS_OFF, %o0
160	brnz,pn	%o0, 3f
161	 mov	-ENOSYS, %o0
162
163	/* Syscall tracing can modify the registers.  */
164	ldx	[%sp + PTREGS_OFF + PT_V9_G1], %g1
165	sethi	%hi(sys_call_table32), %l7
166	ldx	[%sp + PTREGS_OFF + PT_V9_I0], %i0
167	or	%l7, %lo(sys_call_table32), %l7
168	ldx	[%sp + PTREGS_OFF + PT_V9_I1], %i1
169	ldx	[%sp + PTREGS_OFF + PT_V9_I2], %i2
170	ldx	[%sp + PTREGS_OFF + PT_V9_I3], %i3
171	ldx	[%sp + PTREGS_OFF + PT_V9_I4], %i4
172	ldx	[%sp + PTREGS_OFF + PT_V9_I5], %i5
173
174	cmp	%g1, NR_syscalls
175	bgeu,pn	%xcc, 3f
176	 mov	-ENOSYS, %o0
177
178	sll	%g1, 2, %l4
179	srl	%i0, 0, %o0
180	lduw	[%l7 + %l4], %l7
181	srl	%i4, 0, %o4
182	srl	%i1, 0, %o1
183	srl	%i2, 0, %o2
184	ba,pt	%xcc, 5f
185	 srl	%i3, 0, %o3
186
187linux_syscall_trace:
188	call	syscall_trace_enter
189	 add	%sp, PTREGS_OFF, %o0
190	brnz,pn	%o0, 3f
191	 mov	-ENOSYS, %o0
192
193	/* Syscall tracing can modify the registers.  */
194	ldx	[%sp + PTREGS_OFF + PT_V9_G1], %g1
195	sethi	%hi(sys_call_table64), %l7
196	ldx	[%sp + PTREGS_OFF + PT_V9_I0], %i0
197	or	%l7, %lo(sys_call_table64), %l7
198	ldx	[%sp + PTREGS_OFF + PT_V9_I1], %i1
199	ldx	[%sp + PTREGS_OFF + PT_V9_I2], %i2
200	ldx	[%sp + PTREGS_OFF + PT_V9_I3], %i3
201	ldx	[%sp + PTREGS_OFF + PT_V9_I4], %i4
202	ldx	[%sp + PTREGS_OFF + PT_V9_I5], %i5
203
204	cmp	%g1, NR_syscalls
205	bgeu,pn	%xcc, 3f
206	 mov	-ENOSYS, %o0
207
208	sll	%g1, 2, %l4
209	mov	%i0, %o0
210	lduw	[%l7 + %l4], %l7
211	mov	%i1, %o1
212	mov	%i2, %o2
213	mov	%i3, %o3
214	b,pt	%xcc, 2f
215	 mov	%i4, %o4
216
217
218	/* Linux 32-bit system calls enter here... */
219	.align	32
220	.globl	linux_sparc_syscall32
221linux_sparc_syscall32:
222	/* Direct access to user regs, much faster. */
223	cmp	%g1, NR_syscalls			! IEU1	Group
224	bgeu,pn	%xcc, linux_sparc_ni_syscall		! CTI
225	 srl	%i0, 0, %o0				! IEU0
226	sll	%g1, 2, %l4				! IEU0	Group
227	srl	%i4, 0, %o4				! IEU1
228	lduw	[%l7 + %l4], %l7			! Load
229	srl	%i1, 0, %o1				! IEU0	Group
230	ldx	[%g6 + TI_FLAGS], %l0		! Load
231
232	srl	%i3, 0, %o3				! IEU0
233	srl	%i2, 0, %o2				! IEU0	Group
234	andcc	%l0, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT|_TIF_SYSCALL_TRACEPOINT|_TIF_NOHZ), %g0
235	bne,pn	%icc, linux_syscall_trace32		! CTI
236	 mov	%i0, %l5				! IEU1
2375:	call	%l7					! CTI	Group brk forced
238	 srl	%i5, 0, %o5				! IEU1
239	ba,pt	%xcc, 3f
240	 sra	%o0, 0, %o0
241
242	/* Linux native system calls enter here... */
243	.align	32
244	.globl	linux_sparc_syscall
245linux_sparc_syscall:
246	/* Direct access to user regs, much faster. */
247	cmp	%g1, NR_syscalls			! IEU1	Group
248	bgeu,pn	%xcc, linux_sparc_ni_syscall		! CTI
249	 mov	%i0, %o0				! IEU0
250	sll	%g1, 2, %l4				! IEU0	Group
251	mov	%i1, %o1				! IEU1
252	lduw	[%l7 + %l4], %l7			! Load
2534:	mov	%i2, %o2				! IEU0	Group
254	ldx	[%g6 + TI_FLAGS], %l0		! Load
255
256	mov	%i3, %o3				! IEU1
257	mov	%i4, %o4				! IEU0	Group
258	andcc	%l0, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT|_TIF_SYSCALL_TRACEPOINT|_TIF_NOHZ), %g0
259	bne,pn	%icc, linux_syscall_trace		! CTI	Group
260	 mov	%i0, %l5				! IEU0
2612:	call	%l7					! CTI	Group brk forced
262	 mov	%i5, %o5				! IEU0
263	nop
264
2653:	stx	%o0, [%sp + PTREGS_OFF + PT_V9_I0]
266ret_sys_call:
267	ldx	[%sp + PTREGS_OFF + PT_V9_TSTATE], %g3
268	mov	%ulo(TSTATE_XCARRY | TSTATE_ICARRY), %g2
269	sllx	%g2, 32, %g2
270
271	cmp	%o0, -ERESTART_RESTARTBLOCK
272	bgeu,pn	%xcc, 1f
273	 andcc	%l0, (_TIF_SYSCALL_TRACE|_TIF_SECCOMP|_TIF_SYSCALL_AUDIT|_TIF_SYSCALL_TRACEPOINT|_TIF_NOHZ), %g0
274	ldx	[%sp + PTREGS_OFF + PT_V9_TNPC], %l1 ! pc = npc
275
2762:
277	/* System call success, clear Carry condition code. */
278	andn	%g3, %g2, %g3
2793:
280	stx	%g3, [%sp + PTREGS_OFF + PT_V9_TSTATE]
281	bne,pn	%icc, linux_syscall_trace2
282	 add	%l1, 0x4, %l2			! npc = npc+4
283	stx	%l1, [%sp + PTREGS_OFF + PT_V9_TPC]
284	ba,pt	%xcc, rtrap
285	 stx	%l2, [%sp + PTREGS_OFF + PT_V9_TNPC]
286
2871:
288	/* Check if force_successful_syscall_return()
289	 * was invoked.
290	 */
291	ldub	[%g6 + TI_SYS_NOERROR], %l2
292	brnz,pn %l2, 2b
293	 ldx	[%sp + PTREGS_OFF + PT_V9_TNPC], %l1 ! pc = npc
294	/* System call failure, set Carry condition code.
295	 * Also, get abs(errno) to return to the process.
296	 */
297	sub	%g0, %o0, %o0
298	stx	%o0, [%sp + PTREGS_OFF + PT_V9_I0]
299	ba,pt	%xcc, 3b
300	 or	%g3, %g2, %g3
301
302linux_syscall_trace2:
303	call	syscall_trace_leave
304	 add	%sp, PTREGS_OFF, %o0
305	stx	%l1, [%sp + PTREGS_OFF + PT_V9_TPC]
306	ba,pt	%xcc, rtrap
307	 stx	%l2, [%sp + PTREGS_OFF + PT_V9_TNPC]
308