xref: /freebsd/sys/powerpc/powerpc/swtch64.S (revision 7cc42f6d)
1/* $FreeBSD$ */
2/* $NetBSD: locore.S,v 1.24 2000/05/31 05:09:17 thorpej Exp $ */
3
4/*-
5 * Copyright (C) 2001 Benno Rice
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
22 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
23 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
24 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
25 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
26 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27*/
28/*-
29 * Copyright (C) 1995, 1996 Wolfgang Solfrank.
30 * Copyright (C) 1995, 1996 TooLs GmbH.
31 * All rights reserved.
32 *
33 * Redistribution and use in source and binary forms, with or without
34 * modification, are permitted provided that the following conditions
35 * are met:
36 * 1. Redistributions of source code must retain the above copyright
37 *    notice, this list of conditions and the following disclaimer.
38 * 2. Redistributions in binary form must reproduce the above copyright
39 *    notice, this list of conditions and the following disclaimer in the
40 *    documentation and/or other materials provided with the distribution.
41 * 3. All advertising materials mentioning features or use of this software
42 *    must display the following acknowledgement:
43 *	This product includes software developed by TooLs GmbH.
44 * 4. The name of TooLs GmbH may not be used to endorse or promote products
45 *    derived from this software without specific prior written permission.
46 *
47 * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
48 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
49 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
50 * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
51 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
52 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
53 * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
54 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
55 * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
56 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
57 */
58
59#include "assym.inc"
60#include "opt_sched.h"
61
62#include <sys/syscall.h>
63
64#include <machine/trap.h>
65#include <machine/spr.h>
66#include <machine/param.h>
67#include <machine/asm.h>
68
69#ifdef _CALL_ELF
70.abiversion _CALL_ELF
71#endif
72
73TOC_ENTRY(blocked_lock)
74
75/*
76 * void cpu_throw(struct thread *old, struct thread *new)
77 */
78ENTRY(cpu_throw)
79	mr	%r13, %r4
80	li	%r14,0	/* Tell cpu_switchin not to release a thread */
81	li	%r18,0	/* No old pcb flags.  The old thread is extinguished. */
82
83	b	cpu_switchin
84
85/*
86 * void cpu_switch(struct thread *old,
87 *		   struct thread *new,
88 *		   struct mutex *mtx);
89 *
90 * Switch to a new thread saving the current state in the old thread.
91 *
92 * Internally clobbers (not visible outside of this file):
93 * r18	- old thread pcb_flags
94 * r19	- new thread pcb_flags
95 */
96ENTRY(cpu_switch)
97	ld	%r6,TD_PCB(%r3)		/* Get the old thread's PCB ptr */
98	std	%r12,PCB_CONTEXT(%r6)	/* Save the non-volatile GP regs.
99					   These can now be used for scratch */
100	std	%r14,PCB_CONTEXT+2*8(%r6)
101	std	%r15,PCB_CONTEXT+3*8(%r6)
102	std	%r16,PCB_CONTEXT+4*8(%r6)
103	std	%r17,PCB_CONTEXT+5*8(%r6)
104	std	%r18,PCB_CONTEXT+6*8(%r6)
105	std	%r19,PCB_CONTEXT+7*8(%r6)
106	std	%r20,PCB_CONTEXT+8*8(%r6)
107	std	%r21,PCB_CONTEXT+9*8(%r6)
108	std	%r22,PCB_CONTEXT+10*8(%r6)
109	std	%r23,PCB_CONTEXT+11*8(%r6)
110	std	%r24,PCB_CONTEXT+12*8(%r6)
111	std	%r25,PCB_CONTEXT+13*8(%r6)
112	std	%r26,PCB_CONTEXT+14*8(%r6)
113	std	%r27,PCB_CONTEXT+15*8(%r6)
114	std	%r28,PCB_CONTEXT+16*8(%r6)
115	std	%r29,PCB_CONTEXT+17*8(%r6)
116	std	%r30,PCB_CONTEXT+18*8(%r6)
117	std	%r31,PCB_CONTEXT+19*8(%r6)
118
119	mfcr	%r16			/* Save the condition register */
120	std	%r16,PCB_CR(%r6)
121	mflr	%r16			/* Save the link register */
122	std	%r16,PCB_LR(%r6)
123	std	%r1,PCB_SP(%r6)		/* Save the stack pointer */
124	std	%r2,PCB_TOC(%r6)	/* Save the TOC pointer */
125
126	mr	%r14,%r3		/* Copy the old thread ptr... */
127	mr	%r13,%r4		/* and the new thread ptr in curthread*/
128	mr	%r16,%r5		/* and the new lock */
129	mr	%r17,%r6		/* and the PCB */
130
131	stdu	%r1,-48(%r1)
132
133	lwz	%r18, PCB_FLAGS(%r17)
134	andi.	%r7, %r18, PCB_CFSCR
135	beq	1f
136	mfspr	%r6, SPR_FSCR
137	std	%r6, PCB_FSCR(%r17)
138save_ebb:
139	andi.	%r0, %r6, FSCR_EBB
140	beq	save_lm
141	mfspr	%r7, SPR_EBBHR
142	std	%r7, PCB_EBB_EBBHR(%r17)
143	mfspr	%r7, SPR_EBBRR
144	std	%r7, PCB_EBB_EBBRR(%r17)
145	mfspr	%r7, SPR_BESCR
146	std	%r7, PCB_EBB_BESCR(%r17)
147save_lm:
148	andi.	%r0, %r6, FSCR_LM
149	beq	save_tar
150	mfspr	%r7, SPR_LMRR
151	std	%r7, PCB_LMON_LMRR(%r17)
152	mfspr	%r7, SPR_LMSER
153	std	%r7, PCB_LMON_LMSER(%r17)
154save_tar:
155	andi.	%r0, %r6, FSCR_TAR
156	beq	1f
157	mfspr	%r7, SPR_TAR
158	std	%r7, PCB_TAR(%r17)
1591:
160	andi.	%r7, %r18, PCB_CDSCR
161	beq	.L0
162	mfspr	%r6, SPR_DSCRP
163	std	%r6, PCB_DSCR(%r17)
164
165.L0:
166	/* Save FPU context if needed */
167	andi.	%r7, %r18, PCB_FPU
168	beq	.L1
169	bl	save_fpu
170	nop
171
172.L1:
173	mr	%r3,%r14		/* restore old thread ptr */
174	/* Save Altivec context if needed */
175	andi.	%r7, %r18, PCB_VEC
176	beq	.L2
177	bl	save_vec
178	nop
179
180.L2:
181	mr	%r3,%r14		/* restore old thread ptr */
182	bl	pmap_deactivate	/* Deactivate the current pmap */
183	nop
184
185	sync				/* Make sure all of that finished */
186
187cpu_switchin:
188#if defined(SMP) && defined(SCHED_ULE)
189	/* Wait for the new thread to become unblocked */
190	addis	%r6,%r2,TOC_REF(blocked_lock)@ha
191	ld	%r6,TOC_REF(blocked_lock)@l(%r6)
192blocked_loop:
193	ld	%r7,TD_LOCK(%r13)
194	cmpd	%r6,%r7
195	beq-	blocked_loop
196	isync
197#endif
198
199	ld	%r17,TD_PCB(%r13)	/* Get new PCB */
200	ld	%r1,PCB_SP(%r17)	/* Load the stack pointer */
201	addi	%r1,%r1,-48		/* Remember about cpu_switch stack frame */
202
203	/* Release old thread now that we have a stack pointer set up */
204	cmpdi	%r14,0
205	beq-	1f
206	std	%r16,TD_LOCK(%r14)	/* ULE:	update old thread's lock */
207
2081:	mfsprg	%r7,0			/* Get the pcpu pointer */
209	std	%r13,PC_CURTHREAD(%r7)	/* Store new current thread */
210	ld	%r17,TD_PCB(%r13)	/* Store new current PCB */
211	std	%r17,PC_CURPCB(%r7)
212
213	mr	%r3,%r13		/* Get new thread ptr */
214	bl	pmap_activate		/* Activate the new address space */
215	nop
216
217	lwz	%r19, PCB_FLAGS(%r17)
218	/* Restore FPU context if needed */
219	andi.	%r6, %r19, PCB_FPU
220	beq	.L3
221	mr	%r3,%r13		/* Pass curthread to enable_fpu */
222	bl	enable_fpu
223	nop
224
225.L3:
226	/* Restore Altivec context if needed */
227	andi.	%r6, %r19, PCB_VEC
228	beq	.L31
229	mr	%r3,%r13		/* Pass curthread to enable_vec */
230	bl	enable_vec
231	nop
232
233.L31:
234	/* Load custom DSCR on PowerISA 2.06+ CPUs. */
235	/* Load changed FSCR on PowerISA 2.07+ CPUs. */
236	or	%r18,%r18,%r19
237	/* Restore Custom DSCR if needed (zeroes if in old but not new) */
238	andi.	%r6, %r18, PCB_CDSCR
239	beq	.L32
240	ld	%r7, PCB_DSCR(%r17)	/* Load the DSCR register*/
241	mtspr	SPR_DSCRP, %r7
242.L32:
243	/* Restore FSCR if needed (zeroes if in old but not new) */
244	andi.	%r6, %r18, PCB_CFSCR
245	beq	.L4
246	ld	%r7, PCB_FSCR(%r17)	/* Load the FSCR register*/
247	mtspr	SPR_FSCR, %r7
248restore_ebb:
249	andi.	%r0, %r7, FSCR_EBB
250	beq	restore_lm
251	ld	%r6, PCB_EBB_EBBHR(%r17)
252	mtspr	SPR_EBBHR, %r6
253	ld	%r6, PCB_EBB_EBBRR(%r17)
254	mtspr	SPR_EBBRR, %r6
255	ld	%r6, PCB_EBB_BESCR(%r17)
256	mtspr	SPR_BESCR, %r6
257restore_lm:
258	andi.	%r0, %r7, FSCR_LM
259	beq	restore_tar
260	ld	%r6, PCB_LMON_LMRR(%r17)
261	mtspr	SPR_LMRR, %r6
262	ld	%r6, PCB_LMON_LMSER(%r17)
263	mtspr	SPR_LMSER, %r6
264restore_tar:
265	andi.	%r0, %r7, FSCR_TAR
266	beq	.L4
267	ld	%r6, PCB_TAR(%r17)
268	mtspr	SPR_TAR, %r6
269
270	/* thread to restore is in r3 */
271.L4:
272	addi	%r1,%r1,48
273	mr	%r3,%r17		/* Recover PCB ptr */
274	ld	%r12,PCB_CONTEXT(%r3)	/* Load the non-volatile GP regs. */
275	ld	%r14,PCB_CONTEXT+2*8(%r3)
276	ld	%r15,PCB_CONTEXT+3*8(%r3)
277	ld	%r16,PCB_CONTEXT+4*8(%r3)
278	ld	%r17,PCB_CONTEXT+5*8(%r3)
279	ld	%r18,PCB_CONTEXT+6*8(%r3)
280	ld	%r19,PCB_CONTEXT+7*8(%r3)
281	ld	%r20,PCB_CONTEXT+8*8(%r3)
282	ld	%r21,PCB_CONTEXT+9*8(%r3)
283	ld	%r22,PCB_CONTEXT+10*8(%r3)
284	ld	%r23,PCB_CONTEXT+11*8(%r3)
285	ld	%r24,PCB_CONTEXT+12*8(%r3)
286	ld	%r25,PCB_CONTEXT+13*8(%r3)
287	ld	%r26,PCB_CONTEXT+14*8(%r3)
288	ld	%r27,PCB_CONTEXT+15*8(%r3)
289	ld	%r28,PCB_CONTEXT+16*8(%r3)
290	ld	%r29,PCB_CONTEXT+17*8(%r3)
291	ld	%r30,PCB_CONTEXT+18*8(%r3)
292	ld	%r31,PCB_CONTEXT+19*8(%r3)
293	ld	%r5,PCB_CR(%r3)		/* Load the condition register */
294	mtcr	%r5
295	ld	%r5,PCB_LR(%r3)		/* Load the link register */
296	mtlr	%r5
297	ld	%r1,PCB_SP(%r3)		/* Load the stack pointer */
298	ld	%r2,PCB_TOC(%r3)	/* Load the TOC pointer */
299
300	/*
301	 * Perform a dummy stdcx. to clear any reservations we may have
302	 * inherited from the previous thread. It doesn't matter if the
303	 * stdcx succeeds or not. pcb_context[0] can be clobbered.
304	 */
305	stdcx.	%r1, 0, %r3
306	blr
307
308/*
309 * savectx(pcb)
310 * Update pcb, saving current processor state
311 */
312ENTRY(savectx)
313	std	%r12,PCB_CONTEXT(%r3)	/* Save the non-volatile GP regs. */
314	std	%r13,PCB_CONTEXT+1*8(%r3)
315	std	%r14,PCB_CONTEXT+2*8(%r3)
316	std	%r15,PCB_CONTEXT+3*8(%r3)
317	std	%r16,PCB_CONTEXT+4*8(%r3)
318	std	%r17,PCB_CONTEXT+5*8(%r3)
319	std	%r18,PCB_CONTEXT+6*8(%r3)
320	std	%r19,PCB_CONTEXT+7*8(%r3)
321	std	%r20,PCB_CONTEXT+8*8(%r3)
322	std	%r21,PCB_CONTEXT+9*8(%r3)
323	std	%r22,PCB_CONTEXT+10*8(%r3)
324	std	%r23,PCB_CONTEXT+11*8(%r3)
325	std	%r24,PCB_CONTEXT+12*8(%r3)
326	std	%r25,PCB_CONTEXT+13*8(%r3)
327	std	%r26,PCB_CONTEXT+14*8(%r3)
328	std	%r27,PCB_CONTEXT+15*8(%r3)
329	std	%r28,PCB_CONTEXT+16*8(%r3)
330	std	%r29,PCB_CONTEXT+17*8(%r3)
331	std	%r30,PCB_CONTEXT+18*8(%r3)
332	std	%r31,PCB_CONTEXT+19*8(%r3)
333
334	mfcr	%r4			/* Save the condition register */
335	std	%r4,PCB_CR(%r3)
336	std	%r1,PCB_SP(%r3)		/* Save the stack pointer */
337	std	%r2,PCB_TOC(%r3)	/* Save the TOC pointer */
338	mflr	%r4			/* Save the link register */
339	std	%r4,PCB_LR(%r3)
340	blr
341
342/*
343 * fork_trampoline()
344 * Set up the return from cpu_fork()
345 */
346
347ENTRY_NOPROF(fork_trampoline)
348	ld	%r3,CF_FUNC(%r1)
349	ld	%r4,CF_ARG0(%r1)
350	ld	%r5,CF_ARG1(%r1)
351
352	stdu	%r1,-48(%r1)
353	bl	fork_exit
354	nop
355	addi	%r1,%r1,48+CF_SIZE-FSP	/* Allow 8 bytes in front of
356					   trapframe to simulate FRAME_SETUP
357					   does when allocating space for
358					   a frame pointer/saved LR */
359	bl	trapexit
360	nop
361