xref: /NextBSD/sys/mips/mips/swtch.S (revision 5e568154a01fb6be74908baed265f265a56f002f)
1/*	$OpenBSD: locore.S,v 1.18 1998/09/15 10:58:53 pefo Exp $	*/
2/*-
3 * Copyright (c) 1992, 1993
4 *	The Regents of the University of California.  All rights reserved.
5 *
6 * This code is derived from software contributed to Berkeley by
7 * Digital Equipment Corporation and Ralph Campbell.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 * Copyright (C) 1989 Digital Equipment Corporation.
34 * Permission to use, copy, modify, and distribute this software and
35 * its documentation for any purpose and without fee is hereby granted,
36 * provided that the above copyright notice appears in all copies.
37 * Digital Equipment Corporation makes no representations about the
38 * suitability of this software for any purpose.  It is provided "as is"
39 * without express or implied warranty.
40 *
41 * from: Header: /sprite/src/kernel/mach/ds3100.md/RCS/loMem.s,
42 *	v 1.1 89/07/11 17:55:04 nelson Exp  SPRITE (DECWRL)
43 * from: Header: /sprite/src/kernel/mach/ds3100.md/RCS/machAsm.s,
44 *	v 9.2 90/01/29 18:00:39 shirriff Exp  SPRITE (DECWRL)
45 * from: Header: /sprite/src/kernel/vm/ds3100.md/vmPmaxAsm.s,
46 *	v 1.1 89/07/10 14:27:41 nelson Exp  SPRITE (DECWRL)
47 *
48 *	from: @(#)locore.s	8.5 (Berkeley) 1/4/94
49 *	JNPR: swtch.S,v 1.6.2.1 2007/09/10 10:36:50 girish
50 * $FreeBSD$
51 */
52
53/*
54 *	Contains code that is the first executed at boot time plus
55 *	assembly language support routines.
56 */
57
58#include "opt_compat.h"
59#include <sys/syscall.h>
60#include <machine/asm.h>
61#include <machine/cpu.h>
62#include <machine/cpuregs.h>
63#include <machine/regnum.h>
64#include <machine/pte.h>
65#include <machine/pcb.h>
66
67#include "assym.s"
68
69	.set	noreorder			# Noreorder is default style!
70
71/*
72 * Setup for and return to user.
73 */
74LEAF(fork_trampoline)
75	move	a0,s0
76	move	a1,s1
77	jal	_C_LABEL(fork_exit)
78	move	a2,s2			  #BDSlot
79
80	DO_AST
81
82	mfc0	v0, MIPS_COP_0_STATUS
83	and     v0, ~(MIPS_SR_INT_IE)
84	mtc0	v0, MIPS_COP_0_STATUS	# disable interrupts
85	COP0_SYNC
86/*
87 * The use of k1 for storing the PCB pointer must be done only
88 * after interrupts are disabled.  Otherwise it will get overwritten
89 * by the interrupt code.
90 */
91	.set	noat
92	GET_CPU_PCPU(k1)
93	PTR_L	k1, PC_CURPCB(k1)
94
95	RESTORE_U_PCB_REG(t0, MULLO, k1)
96	RESTORE_U_PCB_REG(t1, MULHI, k1)
97	mtlo	t0
98	mthi	t1
99	RESTORE_U_PCB_REG(a0, PC, k1)
100	RESTORE_U_PCB_REG(AT, AST, k1)
101	RESTORE_U_PCB_REG(v0, V0, k1)
102	MTC0	a0, MIPS_COP_0_EXC_PC	# set return address
103
104	RESTORE_U_PCB_REG(v1, V1, k1)
105	RESTORE_U_PCB_REG(a0, A0, k1)
106	RESTORE_U_PCB_REG(a1, A1, k1)
107	RESTORE_U_PCB_REG(a2, A2, k1)
108	RESTORE_U_PCB_REG(a3, A3, k1)
109	RESTORE_U_PCB_REG(t0, T0, k1)
110	RESTORE_U_PCB_REG(t1, T1, k1)
111	RESTORE_U_PCB_REG(t2, T2, k1)
112	RESTORE_U_PCB_REG(t3, T3, k1)
113	RESTORE_U_PCB_REG(ta0, TA0, k1)
114	RESTORE_U_PCB_REG(ta1, TA1, k1)
115	RESTORE_U_PCB_REG(ta2, TA2, k1)
116	RESTORE_U_PCB_REG(ta3, TA3, k1)
117	RESTORE_U_PCB_REG(s0, S0, k1)
118	RESTORE_U_PCB_REG(s1, S1, k1)
119	RESTORE_U_PCB_REG(s2, S2, k1)
120	RESTORE_U_PCB_REG(s3, S3, k1)
121	RESTORE_U_PCB_REG(s4, S4, k1)
122	RESTORE_U_PCB_REG(s5, S5, k1)
123	RESTORE_U_PCB_REG(s6, S6, k1)
124	RESTORE_U_PCB_REG(s7, S7, k1)
125	RESTORE_U_PCB_REG(t8, T8, k1)
126	RESTORE_U_PCB_REG(t9, T9, k1)
127	RESTORE_U_PCB_REG(k0, SR, k1)
128	RESTORE_U_PCB_REG(gp, GP, k1)
129	RESTORE_U_PCB_REG(s8, S8, k1)
130	RESTORE_U_PCB_REG(ra, RA, k1)
131	RESTORE_U_PCB_REG(sp, SP, k1)
132	li	k1, ~MIPS_SR_INT_MASK
133	and	k0, k0, k1
134	mfc0	k1, MIPS_COP_0_STATUS
135	and	k1, k1, MIPS_SR_INT_MASK
136	or	k0, k0, k1
137	mtc0	k0, MIPS_COP_0_STATUS	# switch to user mode (when eret...)
138	HAZARD_DELAY
139	sync
140	eret
141	.set	at
142END(fork_trampoline)
143
144/*
145 * Update pcb, saving current processor state.
146 * Note: this only works if pcbp != curproc's pcb since
147 * cpu_switch() will copy over pcb_context.
148 *
149 *	savectx(struct pcb *pcbp);
150 */
151LEAF(savectx)
152	SAVE_U_PCB_CONTEXT(s0, PCB_REG_S0, a0)
153	SAVE_U_PCB_CONTEXT(s1, PCB_REG_S1, a0)
154	SAVE_U_PCB_CONTEXT(s2, PCB_REG_S2, a0)
155	SAVE_U_PCB_CONTEXT(s3, PCB_REG_S3, a0)
156	mfc0	v0, MIPS_COP_0_STATUS
157	SAVE_U_PCB_CONTEXT(s4, PCB_REG_S4, a0)
158	SAVE_U_PCB_CONTEXT(s5, PCB_REG_S5, a0)
159	SAVE_U_PCB_CONTEXT(s6, PCB_REG_S6, a0)
160	SAVE_U_PCB_CONTEXT(s7, PCB_REG_S7, a0)
161	SAVE_U_PCB_CONTEXT(sp, PCB_REG_SP, a0)
162	SAVE_U_PCB_CONTEXT(s8, PCB_REG_S8, a0)
163	SAVE_U_PCB_CONTEXT(ra, PCB_REG_RA, a0)
164	SAVE_U_PCB_CONTEXT(v0, PCB_REG_SR, a0)
165	SAVE_U_PCB_CONTEXT(gp, PCB_REG_GP, a0)
166
167	move	v0, ra			/* save 'ra' before we trash it */
168	jal	1f
169	nop
1701:
171	SAVE_U_PCB_CONTEXT(ra, PCB_REG_PC, a0)
172	move	ra, v0			/* restore 'ra' before returning */
173
174	j	ra
175	move	v0, zero
176END(savectx)
177
178NESTED(cpu_throw, CALLFRAME_SIZ, ra)
179	mfc0	t0, MIPS_COP_0_STATUS		# t0 = saved status register
180	nop
181	nop
182	and     a3, t0, ~(MIPS_SR_INT_IE)
183	mtc0	a3, MIPS_COP_0_STATUS		# Disable all interrupts
184	ITLBNOPFIX
185	j	mips_sw1			# We're not interested in old
186						# thread's context, so jump
187						# right to action
188	nop					# BDSLOT
189END(cpu_throw)
190
191/*
192 * cpu_switch(struct thread *old, struct thread *new, struct mutex *mtx);
193 *	a0 - old
194 *	a1 - new
195 *	a2 - mtx
196 * Find the highest priority process and resume it.
197 */
198NESTED(cpu_switch, CALLFRAME_SIZ, ra)
199	mfc0	t0, MIPS_COP_0_STATUS		# t0 = saved status register
200	nop
201	nop
202	and     a3, t0, ~(MIPS_SR_INT_IE)
203	mtc0	a3, MIPS_COP_0_STATUS		# Disable all interrupts
204	ITLBNOPFIX
205	beqz	a0, mips_sw1
206	move	a3, a0
207	PTR_L	a0, TD_PCB(a0)		# load PCB addr of curproc
208	SAVE_U_PCB_CONTEXT(sp, PCB_REG_SP, a0)		# save old sp
209	PTR_SUBU	sp, sp, CALLFRAME_SIZ
210	REG_S	ra, CALLFRAME_RA(sp)
211	.mask	0x80000000, (CALLFRAME_RA - CALLFRAME_SIZ)
212	SAVE_U_PCB_CONTEXT(s0, PCB_REG_S0, a0)		# do a 'savectx()'
213	SAVE_U_PCB_CONTEXT(s1, PCB_REG_S1, a0)
214	SAVE_U_PCB_CONTEXT(s2, PCB_REG_S2, a0)
215	SAVE_U_PCB_CONTEXT(s3, PCB_REG_S3, a0)
216	SAVE_U_PCB_CONTEXT(s4, PCB_REG_S4, a0)
217	SAVE_U_PCB_CONTEXT(s5, PCB_REG_S5, a0)
218	SAVE_U_PCB_CONTEXT(s6, PCB_REG_S6, a0)
219	SAVE_U_PCB_CONTEXT(s7, PCB_REG_S7, a0)
220	SAVE_U_PCB_CONTEXT(s8, PCB_REG_S8, a0)
221	SAVE_U_PCB_CONTEXT(ra, PCB_REG_RA, a0)		# save return address
222	SAVE_U_PCB_CONTEXT(t0, PCB_REG_SR, a0)		# save status register
223	SAVE_U_PCB_CONTEXT(gp, PCB_REG_GP, a0)
224	jal	getpc
225	nop
226getpc:
227	SAVE_U_PCB_CONTEXT(ra, PCB_REG_PC, a0)		# save return address
228
229#ifdef CPU_CNMIPS
230
231	lw	t2, TD_MDFLAGS(a3)		# get md_flags
232	and	t1, t2, MDTD_COP2USED
233	beqz	t1, cop2_untouched
234	nop
235
236	/* Clear cop2used flag */
237	and	t2, t2, ~MDTD_COP2USED
238	sw	t2, TD_MDFLAGS(a3)
239
240	and	t2, t0, ~MIPS_SR_COP_2_BIT	# clear COP_2 enable bit
241	SAVE_U_PCB_CONTEXT(t2, PCB_REG_SR, a0)	# save status register
242
243	RESTORE_U_PCB_REG(t0, PS, a0)		# get CPU status register
244	and	t2, t0, ~MIPS_SR_COP_2_BIT	# clear COP_2 enable bit
245	SAVE_U_PCB_REG(t2, PS, a0)		# save stratus register
246
247	/* preserve a0..a3 */
248	move	s0, a0
249	move	s1, a1
250	move	s2, a2
251	move	s3, a3
252
253	/* does kernel own COP2 context? */
254	lw	t1, TD_COP2OWNER(a3)		# get md_cop2owner
255	beqz	t1, userland_cop2		# 0 - it's userland context
256	nop
257
258	PTR_L	a0, TD_COP2(a3)
259	beqz	a0, no_cop2_context
260	nop
261
262	j	do_cop2_save
263	nop
264
265userland_cop2:
266
267	PTR_L	a0, TD_UCOP2(a3)
268	beqz	a0, no_cop2_context
269	nop
270
271do_cop2_save:
272	jal	octeon_cop2_save
273	nop
274
275no_cop2_context:
276	move	a3, s3
277	move	a2, s2
278	move	a1, s1
279	move	a0, s0
280
281cop2_untouched:
282#endif
283
284	PTR_S	a2, TD_LOCK(a3)			# Switchout td_lock
285
286mips_sw1:
287#if defined(SMP) && defined(SCHED_ULE)
288	PTR_LA	t0, _C_LABEL(blocked_lock)
289blocked_loop:
290	PTR_L	t1, TD_LOCK(a1)
291	beq	t0, t1, blocked_loop
292	nop
293#endif
294	move	s7, a1	# Store newthread
295/*
296 * Switch to new context.
297 */
298	GET_CPU_PCPU(a3)
299	PTR_S	a1, PC_CURTHREAD(a3)
300	PTR_L	a2, TD_PCB(a1)
301	PTR_S	a2, PC_CURPCB(a3)
302	PTR_L	v0, TD_KSTACK(a1)
303#if defined(__mips_n64)
304	PTR_LI	s0, MIPS_XKSEG_START
305#else
306	PTR_LI	s0, MIPS_KSEG2_START		# If Uarea addr is below kseg2,
307#endif
308	bltu	v0, s0, sw2			# no need to insert in TLB.
309	PTE_L	a1, TD_UPTE + 0(s7)		# a1 = u. pte #0
310	PTE_L	a2, TD_UPTE + PTESIZE(s7)	# a2 = u. pte #1
311/*
312 * Wiredown the USPACE of newproc in TLB entry#0.  Check whether target
313 * USPACE is already in another place of TLB before that, and if so
314 * invalidate that TLB entry.
315 * NOTE: This is hard coded to UPAGES == 2.
316 * Also, there should be no TLB faults at this point.
317 */
318	MTC0	v0, MIPS_COP_0_TLB_HI		# VPN = va
319	HAZARD_DELAY
320	tlbp					# probe VPN
321	HAZARD_DELAY
322	mfc0	s0, MIPS_COP_0_TLB_INDEX
323	HAZARD_DELAY
324
325	PTR_LI	t1, MIPS_KSEG0_START		# invalidate tlb entry
326	bltz	s0, entry0set
327	nop
328	sll	s0, PAGE_SHIFT + 1
329	addu	t1, s0
330	MTC0	t1, MIPS_COP_0_TLB_HI
331	PTE_MTC0	zero, MIPS_COP_0_TLB_LO0
332	PTE_MTC0	zero, MIPS_COP_0_TLB_LO1
333	HAZARD_DELAY
334	tlbwi
335	HAZARD_DELAY
336	MTC0	v0, MIPS_COP_0_TLB_HI		# set VPN again
337
338entry0set:
339/* SMP!! - Works only for  unshared TLB case - i.e. no v-cpus */
340	mtc0	zero, MIPS_COP_0_TLB_INDEX		# TLB entry #0
341	HAZARD_DELAY
342	PTE_MTC0	a1, MIPS_COP_0_TLB_LO0		# upte[0]
343	HAZARD_DELAY
344	PTE_MTC0	a2, MIPS_COP_0_TLB_LO1		# upte[1]
345	HAZARD_DELAY
346	tlbwi					# set TLB entry #0
347	HAZARD_DELAY
348/*
349 * Now running on new u struct.
350 */
351sw2:
352	PTR_L	s0, TD_PCB(s7)
353	RESTORE_U_PCB_CONTEXT(sp, PCB_REG_SP, s0)
354	PTR_LA	t1, _C_LABEL(pmap_activate)	# s7 = new proc pointer
355	jalr	t1				# s7 = new proc pointer
356	move	a0, s7				# BDSLOT
357/*
358 * Restore registers and return.
359 */
360	move	a0, s0
361	RESTORE_U_PCB_CONTEXT(gp, PCB_REG_GP, a0)
362	RESTORE_U_PCB_CONTEXT(v0, PCB_REG_SR, a0)	# restore kernel context
363	RESTORE_U_PCB_CONTEXT(ra, PCB_REG_RA, a0)
364	RESTORE_U_PCB_CONTEXT(s0, PCB_REG_S0, a0)
365	RESTORE_U_PCB_CONTEXT(s1, PCB_REG_S1, a0)
366	RESTORE_U_PCB_CONTEXT(s2, PCB_REG_S2, a0)
367	RESTORE_U_PCB_CONTEXT(s3, PCB_REG_S3, a0)
368	RESTORE_U_PCB_CONTEXT(s4, PCB_REG_S4, a0)
369	RESTORE_U_PCB_CONTEXT(s5, PCB_REG_S5, a0)
370	RESTORE_U_PCB_CONTEXT(s6, PCB_REG_S6, a0)
371	RESTORE_U_PCB_CONTEXT(s7, PCB_REG_S7, a0)
372	RESTORE_U_PCB_CONTEXT(s8, PCB_REG_S8, a0)
373
374	mfc0	t0, MIPS_COP_0_STATUS
375	and	t0, t0, MIPS_SR_INT_MASK
376	and	v0, v0, ~MIPS_SR_INT_MASK
377	or	v0, v0, t0
378	mtc0	v0, MIPS_COP_0_STATUS
379	ITLBNOPFIX
380
381	j	ra
382	nop
383END(cpu_switch)
384
385/*----------------------------------------------------------------------------
386 *
387 * MipsSwitchFPState --
388 *
389 *	Save the current state into 'from' and restore it from 'to'.
390 *
391 *	MipsSwitchFPState(from, to)
392 *		struct thread *from;
393 *		struct trapframe *to;
394 *
395 * Results:
396 *	None.
397 *
398 * Side effects:
399 *	None.
400 *
401 *----------------------------------------------------------------------------
402 */
403LEAF(MipsSwitchFPState)
404	mfc0	t1, MIPS_COP_0_STATUS	# Save old SR
405	li	t0, MIPS_SR_COP_1_BIT	# enable the coprocessor
406	mtc0	t0, MIPS_COP_0_STATUS
407	ITLBNOPFIX
408
409	beq	a0, zero, 1f		# skip save if NULL pointer
410	nop
411/*
412 * First read out the status register to make sure that all FP operations
413 * have completed.
414 */
415	PTR_L	a0, TD_PCB(a0)			# get pointer to pcb for proc
416	cfc1	t0, MIPS_FPU_CSR		# stall til FP done
417	cfc1	t0, MIPS_FPU_CSR		# now get status
418	li	t3, ~MIPS_SR_COP_1_BIT
419	RESTORE_U_PCB_REG(t2, PS, a0)		# get CPU status register
420	SAVE_U_PCB_FPSR(t0, FSR_NUM, a0)	# save FP status
421	and	t2, t2, t3			# clear COP_1 enable bit
422	SAVE_U_PCB_REG(t2, PS, a0)		# save new status register
423/*
424 * Save the floating point registers.
425 */
426	SAVE_U_PCB_FPREG($f0, F0_NUM, a0)
427	SAVE_U_PCB_FPREG($f1, F1_NUM, a0)
428	SAVE_U_PCB_FPREG($f2, F2_NUM, a0)
429	SAVE_U_PCB_FPREG($f3, F3_NUM, a0)
430	SAVE_U_PCB_FPREG($f4, F4_NUM, a0)
431	SAVE_U_PCB_FPREG($f5, F5_NUM, a0)
432	SAVE_U_PCB_FPREG($f6, F6_NUM, a0)
433	SAVE_U_PCB_FPREG($f7, F7_NUM, a0)
434	SAVE_U_PCB_FPREG($f8, F8_NUM, a0)
435	SAVE_U_PCB_FPREG($f9, F9_NUM, a0)
436	SAVE_U_PCB_FPREG($f10, F10_NUM, a0)
437	SAVE_U_PCB_FPREG($f11, F11_NUM, a0)
438	SAVE_U_PCB_FPREG($f12, F12_NUM, a0)
439	SAVE_U_PCB_FPREG($f13, F13_NUM, a0)
440	SAVE_U_PCB_FPREG($f14, F14_NUM, a0)
441	SAVE_U_PCB_FPREG($f15, F15_NUM, a0)
442	SAVE_U_PCB_FPREG($f16, F16_NUM, a0)
443	SAVE_U_PCB_FPREG($f17, F17_NUM, a0)
444	SAVE_U_PCB_FPREG($f18, F18_NUM, a0)
445	SAVE_U_PCB_FPREG($f19, F19_NUM, a0)
446	SAVE_U_PCB_FPREG($f20, F20_NUM, a0)
447	SAVE_U_PCB_FPREG($f21, F21_NUM, a0)
448	SAVE_U_PCB_FPREG($f22, F22_NUM, a0)
449	SAVE_U_PCB_FPREG($f23, F23_NUM, a0)
450	SAVE_U_PCB_FPREG($f24, F24_NUM, a0)
451	SAVE_U_PCB_FPREG($f25, F25_NUM, a0)
452	SAVE_U_PCB_FPREG($f26, F26_NUM, a0)
453	SAVE_U_PCB_FPREG($f27, F27_NUM, a0)
454	SAVE_U_PCB_FPREG($f28, F28_NUM, a0)
455	SAVE_U_PCB_FPREG($f29, F29_NUM, a0)
456	SAVE_U_PCB_FPREG($f30, F30_NUM, a0)
457	SAVE_U_PCB_FPREG($f31, F31_NUM, a0)
458
4591:
460/*
461 *  Restore the floating point registers.
462 */
463	RESTORE_U_PCB_FPSR(t0, FSR_NUM, a1)	# get status register
464	RESTORE_U_PCB_FPREG($f0, F0_NUM, a1)
465	RESTORE_U_PCB_FPREG($f1, F1_NUM, a1)
466	RESTORE_U_PCB_FPREG($f2, F2_NUM, a1)
467	RESTORE_U_PCB_FPREG($f3, F3_NUM, a1)
468	RESTORE_U_PCB_FPREG($f4, F4_NUM, a1)
469	RESTORE_U_PCB_FPREG($f5, F5_NUM, a1)
470	RESTORE_U_PCB_FPREG($f6, F6_NUM, a1)
471	RESTORE_U_PCB_FPREG($f7, F7_NUM, a1)
472	RESTORE_U_PCB_FPREG($f8, F8_NUM, a1)
473	RESTORE_U_PCB_FPREG($f9, F9_NUM, a1)
474	RESTORE_U_PCB_FPREG($f10, F10_NUM, a1)
475	RESTORE_U_PCB_FPREG($f11, F11_NUM, a1)
476	RESTORE_U_PCB_FPREG($f12, F12_NUM, a1)
477	RESTORE_U_PCB_FPREG($f13, F13_NUM, a1)
478	RESTORE_U_PCB_FPREG($f14, F14_NUM, a1)
479	RESTORE_U_PCB_FPREG($f15, F15_NUM, a1)
480	RESTORE_U_PCB_FPREG($f16, F16_NUM, a1)
481	RESTORE_U_PCB_FPREG($f17, F17_NUM, a1)
482	RESTORE_U_PCB_FPREG($f18, F18_NUM, a1)
483	RESTORE_U_PCB_FPREG($f19, F19_NUM, a1)
484	RESTORE_U_PCB_FPREG($f20, F20_NUM, a1)
485	RESTORE_U_PCB_FPREG($f21, F21_NUM, a1)
486	RESTORE_U_PCB_FPREG($f22, F22_NUM, a1)
487	RESTORE_U_PCB_FPREG($f23, F23_NUM, a1)
488	RESTORE_U_PCB_FPREG($f24, F24_NUM, a1)
489	RESTORE_U_PCB_FPREG($f25, F25_NUM, a1)
490	RESTORE_U_PCB_FPREG($f26, F26_NUM, a1)
491	RESTORE_U_PCB_FPREG($f27, F27_NUM, a1)
492	RESTORE_U_PCB_FPREG($f28, F28_NUM, a1)
493	RESTORE_U_PCB_FPREG($f29, F29_NUM, a1)
494	RESTORE_U_PCB_FPREG($f30, F30_NUM, a1)
495	RESTORE_U_PCB_FPREG($f31, F31_NUM, a1)
496
497	and	t0, t0, ~MIPS_FPU_EXCEPTION_BITS
498	ctc1	t0, MIPS_FPU_CSR
499	nop
500
501	mtc0	t1, MIPS_COP_0_STATUS		# Restore the status register.
502	ITLBNOPFIX
503	j	ra
504	nop
505END(MipsSwitchFPState)
506
507/*----------------------------------------------------------------------------
508 *
509 * MipsSaveCurFPState --
510 *
511 *	Save the current floating point coprocessor state.
512 *
513 *	MipsSaveCurFPState(td)
514 *		struct thread *td;
515 *
516 * Results:
517 *	None.
518 *
519 * Side effects:
520 *	machFPCurProcPtr is cleared.
521 *
522 *----------------------------------------------------------------------------
523 */
524LEAF(MipsSaveCurFPState)
525	PTR_L	a0, TD_PCB(a0)			# get pointer to pcb for thread
526	mfc0	t1, MIPS_COP_0_STATUS		# Disable interrupts and
527	li	t0, MIPS_SR_COP_1_BIT		#  enable the coprocessor
528	mtc0	t0, MIPS_COP_0_STATUS
529	ITLBNOPFIX
530	GET_CPU_PCPU(a1)
531	PTR_S	zero, PC_FPCURTHREAD(a1)	# indicate state has been saved
532/*
533 * First read out the status register to make sure that all FP operations
534 * have completed.
535 */
536	RESTORE_U_PCB_REG(t2, PS, a0)		# get CPU status register
537	li	t3, ~MIPS_SR_COP_1_BIT
538	and	t2, t2, t3			# clear COP_1 enable bit
539	cfc1	t0, MIPS_FPU_CSR		# stall til FP done
540	cfc1	t0, MIPS_FPU_CSR		# now get status
541	SAVE_U_PCB_REG(t2, PS, a0)		# save new status register
542	SAVE_U_PCB_FPSR(t0, FSR_NUM, a0)	# save FP status
543/*
544 * Save the floating point registers.
545 */
546	SAVE_U_PCB_FPREG($f0, F0_NUM, a0)
547	SAVE_U_PCB_FPREG($f1, F1_NUM, a0)
548	SAVE_U_PCB_FPREG($f2, F2_NUM, a0)
549	SAVE_U_PCB_FPREG($f3, F3_NUM, a0)
550	SAVE_U_PCB_FPREG($f4, F4_NUM, a0)
551	SAVE_U_PCB_FPREG($f5, F5_NUM, a0)
552	SAVE_U_PCB_FPREG($f6, F6_NUM, a0)
553	SAVE_U_PCB_FPREG($f7, F7_NUM, a0)
554	SAVE_U_PCB_FPREG($f8, F8_NUM, a0)
555	SAVE_U_PCB_FPREG($f9, F9_NUM, a0)
556	SAVE_U_PCB_FPREG($f10, F10_NUM, a0)
557	SAVE_U_PCB_FPREG($f11, F11_NUM, a0)
558	SAVE_U_PCB_FPREG($f12, F12_NUM, a0)
559	SAVE_U_PCB_FPREG($f13, F13_NUM, a0)
560	SAVE_U_PCB_FPREG($f14, F14_NUM, a0)
561	SAVE_U_PCB_FPREG($f15, F15_NUM, a0)
562	SAVE_U_PCB_FPREG($f16, F16_NUM, a0)
563	SAVE_U_PCB_FPREG($f17, F17_NUM, a0)
564	SAVE_U_PCB_FPREG($f18, F18_NUM, a0)
565	SAVE_U_PCB_FPREG($f19, F19_NUM, a0)
566	SAVE_U_PCB_FPREG($f20, F20_NUM, a0)
567	SAVE_U_PCB_FPREG($f21, F21_NUM, a0)
568	SAVE_U_PCB_FPREG($f22, F22_NUM, a0)
569	SAVE_U_PCB_FPREG($f23, F23_NUM, a0)
570	SAVE_U_PCB_FPREG($f24, F24_NUM, a0)
571	SAVE_U_PCB_FPREG($f25, F25_NUM, a0)
572	SAVE_U_PCB_FPREG($f26, F26_NUM, a0)
573	SAVE_U_PCB_FPREG($f27, F27_NUM, a0)
574	SAVE_U_PCB_FPREG($f28, F28_NUM, a0)
575	SAVE_U_PCB_FPREG($f29, F29_NUM, a0)
576	SAVE_U_PCB_FPREG($f30, F30_NUM, a0)
577	SAVE_U_PCB_FPREG($f31, F31_NUM, a0)
578
579	mtc0	t1, MIPS_COP_0_STATUS		# Restore the status register.
580	ITLBNOPFIX
581	j	ra
582	nop
583END(MipsSaveCurFPState)
584
585/*
586 * This code is copied the user's stack for returning from signal handlers
587 * (see sendsig() and sigreturn()). We have to compute the address
588 * of the sigcontext struct for the sigreturn call.
589 */
590	.globl	_C_LABEL(sigcode)
591_C_LABEL(sigcode):
592	PTR_ADDU	a0, sp, SIGF_UC		# address of ucontext
593	li		v0, SYS_sigreturn
594# sigreturn (ucp)
595	syscall
596	break	0				# just in case sigreturn fails
597	.globl	_C_LABEL(esigcode)
598_C_LABEL(esigcode):
599
600	.data
601	.globl	szsigcode
602szsigcode:
603	.long	esigcode-sigcode
604	.text
605
606#if (defined(__mips_n32) || defined(__mips_n64)) && defined(COMPAT_FREEBSD32)
607	.globl	_C_LABEL(sigcode32)
608_C_LABEL(sigcode32):
609	addu		a0, sp, SIGF32_UC	# address of ucontext
610	li		v0, SYS_sigreturn
611# sigreturn (ucp)
612	syscall
613	break	0				# just in case sigreturn fails
614	.globl	_C_LABEL(esigcode32)
615_C_LABEL(esigcode32):
616
617	.data
618	.globl	szsigcode32
619szsigcode32:
620	.long	esigcode32-sigcode32
621	.text
622#endif
623