xref: /freebsd/sys/powerpc/aim/aim_machdep.c (revision 61928298)
1 /*-
2  * Copyright (C) 1995, 1996 Wolfgang Solfrank.
3  * Copyright (C) 1995, 1996 TooLs GmbH.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *      This product includes software developed by TooLs GmbH.
17  * 4. The name of TooLs GmbH may not be used to endorse or promote products
18  *    derived from this software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY TOOLS GMBH ``AS IS'' AND ANY EXPRESS OR
21  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
22  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
23  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
24  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 /*-
32  * Copyright (C) 2001 Benno Rice
33  * All rights reserved.
34  *
35  * Redistribution and use in source and binary forms, with or without
36  * modification, are permitted provided that the following conditions
37  * are met:
38  * 1. Redistributions of source code must retain the above copyright
39  *    notice, this list of conditions and the following disclaimer.
40  * 2. Redistributions in binary form must reproduce the above copyright
41  *    notice, this list of conditions and the following disclaimer in the
42  *    documentation and/or other materials provided with the distribution.
43  *
44  * THIS SOFTWARE IS PROVIDED BY Benno Rice ``AS IS'' AND ANY EXPRESS OR
45  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
46  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
47  * IN NO EVENT SHALL TOOLS GMBH BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
48  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
49  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
50  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
51  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
52  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
53  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
54  *	$NetBSD: machdep.c,v 1.74.2.1 2000/11/01 16:13:48 tv Exp $
55  */
56 
57 #include <sys/cdefs.h>
58 __FBSDID("$FreeBSD$");
59 
60 #include "opt_compat.h"
61 #include "opt_ddb.h"
62 #include "opt_kstack_pages.h"
63 #include "opt_platform.h"
64 
65 #include <sys/param.h>
66 #include <sys/proc.h>
67 #include <sys/systm.h>
68 #include <sys/bio.h>
69 #include <sys/buf.h>
70 #include <sys/bus.h>
71 #include <sys/cons.h>
72 #include <sys/cpu.h>
73 #include <sys/eventhandler.h>
74 #include <sys/exec.h>
75 #include <sys/imgact.h>
76 #include <sys/kdb.h>
77 #include <sys/kernel.h>
78 #include <sys/ktr.h>
79 #include <sys/linker.h>
80 #include <sys/lock.h>
81 #include <sys/malloc.h>
82 #include <sys/mbuf.h>
83 #include <sys/msgbuf.h>
84 #include <sys/mutex.h>
85 #include <sys/ptrace.h>
86 #include <sys/reboot.h>
87 #include <sys/rwlock.h>
88 #include <sys/signalvar.h>
89 #include <sys/syscallsubr.h>
90 #include <sys/sysctl.h>
91 #include <sys/sysent.h>
92 #include <sys/sysproto.h>
93 #include <sys/ucontext.h>
94 #include <sys/uio.h>
95 #include <sys/vmmeter.h>
96 #include <sys/vnode.h>
97 
98 #include <net/netisr.h>
99 
100 #include <vm/vm.h>
101 #include <vm/vm_extern.h>
102 #include <vm/vm_kern.h>
103 #include <vm/vm_page.h>
104 #include <vm/vm_map.h>
105 #include <vm/vm_object.h>
106 #include <vm/vm_pager.h>
107 
108 #include <machine/altivec.h>
109 #ifndef __powerpc64__
110 #include <machine/bat.h>
111 #endif
112 #include <machine/cpu.h>
113 #include <machine/elf.h>
114 #include <machine/fpu.h>
115 #include <machine/hid.h>
116 #include <machine/kdb.h>
117 #include <machine/md_var.h>
118 #include <machine/metadata.h>
119 #include <machine/mmuvar.h>
120 #include <machine/pcb.h>
121 #include <machine/reg.h>
122 #include <machine/sigframe.h>
123 #include <machine/spr.h>
124 #include <machine/trap.h>
125 #include <machine/vmparam.h>
126 #include <machine/ofw_machdep.h>
127 
128 #include <ddb/ddb.h>
129 
130 #include <dev/ofw/openfirm.h>
131 
132 #ifdef __powerpc64__
133 #include "mmu_oea64.h"
134 #endif
135 
136 #ifndef __powerpc64__
137 struct bat	battable[16];
138 #endif
139 
140 #ifndef __powerpc64__
141 /* Bits for running on 64-bit systems in 32-bit mode. */
142 extern void	*testppc64, *testppc64size;
143 extern void	*restorebridge, *restorebridgesize;
144 extern void	*rfid_patch, *rfi_patch1, *rfi_patch2;
145 extern void	*trapcode64;
146 
147 extern Elf_Addr	_GLOBAL_OFFSET_TABLE_[];
148 #endif
149 
150 extern void	*rstcode, *rstcodeend;
151 extern void	*trapcode, *trapcodeend;
152 extern void	*generictrap, *generictrap64;
153 extern void	*alitrap, *aliend;
154 extern void	*dsitrap, *dsiend;
155 extern void	*decrint, *decrsize;
156 extern void     *extint, *extsize;
157 extern void	*dblow, *dbend;
158 extern void	*imisstrap, *imisssize;
159 extern void	*dlmisstrap, *dlmisssize;
160 extern void	*dsmisstrap, *dsmisssize;
161 
162 extern void *ap_pcpu;
163 
164 void aim_cpu_init(vm_offset_t toc);
165 
166 void
167 aim_cpu_init(vm_offset_t toc)
168 {
169 	size_t		trap_offset, trapsize;
170 	vm_offset_t	trap;
171 	register_t	msr, scratch;
172 	uint8_t		*cache_check;
173 	int		cacheline_warn;
174 	#ifndef __powerpc64__
175 	int		ppc64;
176 	#endif
177 
178 	trap_offset = 0;
179 	cacheline_warn = 0;
180 
181 	/* General setup for AIM CPUs */
182 	psl_kernset = PSL_EE | PSL_ME | PSL_IR | PSL_DR | PSL_RI;
183 
184 #ifdef __powerpc64__
185 	psl_kernset |= PSL_SF;
186 	if (mfmsr() & PSL_HV)
187 		psl_kernset |= PSL_HV;
188 #endif
189 	psl_userset = psl_kernset | PSL_PR;
190 #ifdef __powerpc64__
191 	psl_userset32 = psl_userset & ~PSL_SF;
192 #endif
193 
194 	/* Bits that users aren't allowed to change */
195 	psl_userstatic = ~(PSL_VEC | PSL_FP | PSL_FE0 | PSL_FE1);
196 	/*
197 	 * Mask bits from the SRR1 that aren't really the MSR:
198 	 * Bits 1-4, 10-15 (ppc32), 33-36, 42-47 (ppc64)
199 	 */
200 	psl_userstatic &= ~0x783f0000UL;
201 
202 	/* Various very early CPU fix ups */
203 	switch (mfpvr() >> 16) {
204 		/*
205 		 * PowerPC 970 CPUs have a misfeature requested by Apple that
206 		 * makes them pretend they have a 32-byte cacheline. Turn this
207 		 * off before we measure the cacheline size.
208 		 */
209 		case IBM970:
210 		case IBM970FX:
211 		case IBM970MP:
212 		case IBM970GX:
213 			scratch = mfspr(SPR_HID5);
214 			scratch &= ~HID5_970_DCBZ_SIZE_HI;
215 			mtspr(SPR_HID5, scratch);
216 			break;
217 	#ifdef __powerpc64__
218 		case IBMPOWER7:
219 		case IBMPOWER7PLUS:
220 		case IBMPOWER8:
221 		case IBMPOWER8E:
222 			/* XXX: get from ibm,slb-size in device tree */
223 			n_slbs = 32;
224 			break;
225 	#endif
226 	}
227 
228 	/*
229 	 * Initialize the interrupt tables and figure out our cache line
230 	 * size and whether or not we need the 64-bit bridge code.
231 	 */
232 
233 	/*
234 	 * Disable translation in case the vector area hasn't been
235 	 * mapped (G5). Note that no OFW calls can be made until
236 	 * translation is re-enabled.
237 	 */
238 
239 	msr = mfmsr();
240 	mtmsr((msr & ~(PSL_IR | PSL_DR)) | PSL_RI);
241 
242 	/*
243 	 * Measure the cacheline size using dcbz
244 	 *
245 	 * Use EXC_PGM as a playground. We are about to overwrite it
246 	 * anyway, we know it exists, and we know it is cache-aligned.
247 	 */
248 
249 	cache_check = (void *)EXC_PGM;
250 
251 	for (cacheline_size = 0; cacheline_size < 0x100; cacheline_size++)
252 		cache_check[cacheline_size] = 0xff;
253 
254 	__asm __volatile("dcbz 0,%0":: "r" (cache_check) : "memory");
255 
256 	/* Find the first byte dcbz did not zero to get the cache line size */
257 	for (cacheline_size = 0; cacheline_size < 0x100 &&
258 	    cache_check[cacheline_size] == 0; cacheline_size++);
259 
260 	/* Work around psim bug */
261 	if (cacheline_size == 0) {
262 		cacheline_warn = 1;
263 		cacheline_size = 32;
264 	}
265 
266 	#ifndef __powerpc64__
267 	/*
268 	 * Figure out whether we need to use the 64 bit PMAP. This works by
269 	 * executing an instruction that is only legal on 64-bit PPC (mtmsrd),
270 	 * and setting ppc64 = 0 if that causes a trap.
271 	 */
272 
273 	ppc64 = 1;
274 
275 	bcopy(&testppc64, (void *)EXC_PGM,  (size_t)&testppc64size);
276 	__syncicache((void *)EXC_PGM, (size_t)&testppc64size);
277 
278 	__asm __volatile("\
279 		mfmsr %0;	\
280 		mtsprg2 %1;	\
281 				\
282 		mtmsrd %0;	\
283 		mfsprg2 %1;"
284 	    : "=r"(scratch), "=r"(ppc64));
285 
286 	if (ppc64)
287 		cpu_features |= PPC_FEATURE_64;
288 
289 	/*
290 	 * Now copy restorebridge into all the handlers, if necessary,
291 	 * and set up the trap tables.
292 	 */
293 
294 	if (cpu_features & PPC_FEATURE_64) {
295 		/* Patch the two instances of rfi -> rfid */
296 		bcopy(&rfid_patch,&rfi_patch1,4);
297 	#ifdef KDB
298 		/* rfi_patch2 is at the end of dbleave */
299 		bcopy(&rfid_patch,&rfi_patch2,4);
300 	#endif
301 	}
302 	#else /* powerpc64 */
303 	cpu_features |= PPC_FEATURE_64;
304 	#endif
305 
306 	trapsize = (size_t)&trapcodeend - (size_t)&trapcode;
307 
308 	/*
309 	 * Copy generic handler into every possible trap. Special cases will get
310 	 * different ones in a minute.
311 	 */
312 	for (trap = EXC_RST; trap < EXC_LAST; trap += 0x20)
313 		bcopy(&trapcode, (void *)trap, trapsize);
314 
315 	#ifndef __powerpc64__
316 	if (cpu_features & PPC_FEATURE_64) {
317 		/*
318 		 * Copy a code snippet to restore 32-bit bridge mode
319 		 * to the top of every non-generic trap handler
320 		 */
321 
322 		trap_offset += (size_t)&restorebridgesize;
323 		bcopy(&restorebridge, (void *)EXC_RST, trap_offset);
324 		bcopy(&restorebridge, (void *)EXC_DSI, trap_offset);
325 		bcopy(&restorebridge, (void *)EXC_ALI, trap_offset);
326 		bcopy(&restorebridge, (void *)EXC_PGM, trap_offset);
327 		bcopy(&restorebridge, (void *)EXC_MCHK, trap_offset);
328 		bcopy(&restorebridge, (void *)EXC_TRC, trap_offset);
329 		bcopy(&restorebridge, (void *)EXC_BPT, trap_offset);
330 	}
331 	#endif
332 
333 	bcopy(&rstcode, (void *)(EXC_RST + trap_offset), (size_t)&rstcodeend -
334 	    (size_t)&rstcode);
335 
336 #ifdef KDB
337 	bcopy(&dblow, (void *)(EXC_MCHK + trap_offset), (size_t)&dbend -
338 	    (size_t)&dblow);
339 	bcopy(&dblow, (void *)(EXC_PGM + trap_offset), (size_t)&dbend -
340 	    (size_t)&dblow);
341 	bcopy(&dblow, (void *)(EXC_TRC + trap_offset), (size_t)&dbend -
342 	    (size_t)&dblow);
343 	bcopy(&dblow, (void *)(EXC_BPT + trap_offset), (size_t)&dbend -
344 	    (size_t)&dblow);
345 #endif
346 	bcopy(&alitrap,  (void *)(EXC_ALI + trap_offset),  (size_t)&aliend -
347 	    (size_t)&alitrap);
348 	bcopy(&dsitrap,  (void *)(EXC_DSI + trap_offset),  (size_t)&dsiend -
349 	    (size_t)&dsitrap);
350 
351 	#ifdef __powerpc64__
352 	/* Set TOC base so that the interrupt code can get at it */
353 	*((void **)TRAP_GENTRAP) = &generictrap;
354 	*((register_t *)TRAP_TOCBASE) = toc;
355 	#else
356 	/* Set branch address for trap code */
357 	if (cpu_features & PPC_FEATURE_64)
358 		*((void **)TRAP_GENTRAP) = &generictrap64;
359 	else
360 		*((void **)TRAP_GENTRAP) = &generictrap;
361 	*((void **)TRAP_TOCBASE) = _GLOBAL_OFFSET_TABLE_;
362 
363 	/* G2-specific TLB miss helper handlers */
364 	bcopy(&imisstrap, (void *)EXC_IMISS,  (size_t)&imisssize);
365 	bcopy(&dlmisstrap, (void *)EXC_DLMISS,  (size_t)&dlmisssize);
366 	bcopy(&dsmisstrap, (void *)EXC_DSMISS,  (size_t)&dsmisssize);
367 	#endif
368 	__syncicache(EXC_RSVD, EXC_LAST - EXC_RSVD);
369 
370 	/*
371 	 * Restore MSR
372 	 */
373 	mtmsr(msr);
374 
375 	/* Warn if cachline size was not determined */
376 	if (cacheline_warn == 1) {
377 		printf("WARNING: cacheline size undetermined, setting to 32\n");
378 	}
379 
380 	/*
381 	 * Initialise virtual memory. Use BUS_PROBE_GENERIC priority
382 	 * in case the platform module had a better idea of what we
383 	 * should do.
384 	 */
385 	if (cpu_features & PPC_FEATURE_64)
386 		pmap_mmu_install(MMU_TYPE_G5, BUS_PROBE_GENERIC);
387 	else
388 		pmap_mmu_install(MMU_TYPE_OEA, BUS_PROBE_GENERIC);
389 }
390 
391 /*
392  * Shutdown the CPU as much as possible.
393  */
394 void
395 cpu_halt(void)
396 {
397 
398 	OF_exit();
399 }
400 
401 int
402 ptrace_single_step(struct thread *td)
403 {
404 	struct trapframe *tf;
405 
406 	tf = td->td_frame;
407 	tf->srr1 |= PSL_SE;
408 
409 	return (0);
410 }
411 
412 int
413 ptrace_clear_single_step(struct thread *td)
414 {
415 	struct trapframe *tf;
416 
417 	tf = td->td_frame;
418 	tf->srr1 &= ~PSL_SE;
419 
420 	return (0);
421 }
422 
423 void
424 kdb_cpu_clear_singlestep(void)
425 {
426 
427 	kdb_frame->srr1 &= ~PSL_SE;
428 }
429 
430 void
431 kdb_cpu_set_singlestep(void)
432 {
433 
434 	kdb_frame->srr1 |= PSL_SE;
435 }
436 
437 /*
438  * Initialise a struct pcpu.
439  */
440 void
441 cpu_pcpu_init(struct pcpu *pcpu, int cpuid, size_t sz)
442 {
443 #ifdef __powerpc64__
444 /* Copy the SLB contents from the current CPU */
445 memcpy(pcpu->pc_slb, PCPU_GET(slb), sizeof(pcpu->pc_slb));
446 #endif
447 }
448 
449 #ifndef __powerpc64__
450 uint64_t
451 va_to_vsid(pmap_t pm, vm_offset_t va)
452 {
453 	return ((pm->pm_sr[(uintptr_t)va >> ADDR_SR_SHFT]) & SR_VSID_MASK);
454 }
455 
456 #endif
457 
458 vm_offset_t
459 pmap_early_io_map(vm_paddr_t pa, vm_size_t size)
460 {
461 
462 	return (pa);
463 }
464 
465 /* From p3-53 of the MPC7450 RISC Microprocessor Family Reference Manual */
466 void
467 flush_disable_caches(void)
468 {
469 	register_t msr;
470 	register_t msscr0;
471 	register_t cache_reg;
472 	volatile uint32_t *memp;
473 	uint32_t temp;
474 	int i;
475 	int x;
476 
477 	msr = mfmsr();
478 	powerpc_sync();
479 	mtmsr(msr & ~(PSL_EE | PSL_DR));
480 	msscr0 = mfspr(SPR_MSSCR0);
481 	msscr0 &= ~MSSCR0_L2PFE;
482 	mtspr(SPR_MSSCR0, msscr0);
483 	powerpc_sync();
484 	isync();
485 	__asm__ __volatile__("dssall; sync");
486 	powerpc_sync();
487 	isync();
488 	__asm__ __volatile__("dcbf 0,%0" :: "r"(0));
489 	__asm__ __volatile__("dcbf 0,%0" :: "r"(0));
490 	__asm__ __volatile__("dcbf 0,%0" :: "r"(0));
491 
492 	/* Lock the L1 Data cache. */
493 	mtspr(SPR_LDSTCR, mfspr(SPR_LDSTCR) | 0xFF);
494 	powerpc_sync();
495 	isync();
496 
497 	mtspr(SPR_LDSTCR, 0);
498 
499 	/*
500 	 * Perform this in two stages: Flush the cache starting in RAM, then do it
501 	 * from ROM.
502 	 */
503 	memp = (volatile uint32_t *)0x00000000;
504 	for (i = 0; i < 128 * 1024; i++) {
505 		temp = *memp;
506 		__asm__ __volatile__("dcbf 0,%0" :: "r"(memp));
507 		memp += 32/sizeof(*memp);
508 	}
509 
510 	memp = (volatile uint32_t *)0xfff00000;
511 	x = 0xfe;
512 
513 	for (; x != 0xff;) {
514 		mtspr(SPR_LDSTCR, x);
515 		for (i = 0; i < 128; i++) {
516 			temp = *memp;
517 			__asm__ __volatile__("dcbf 0,%0" :: "r"(memp));
518 			memp += 32/sizeof(*memp);
519 		}
520 		x = ((x << 1) | 1) & 0xff;
521 	}
522 	mtspr(SPR_LDSTCR, 0);
523 
524 	cache_reg = mfspr(SPR_L2CR);
525 	if (cache_reg & L2CR_L2E) {
526 		cache_reg &= ~(L2CR_L2IO_7450 | L2CR_L2DO_7450);
527 		mtspr(SPR_L2CR, cache_reg);
528 		powerpc_sync();
529 		mtspr(SPR_L2CR, cache_reg | L2CR_L2HWF);
530 		while (mfspr(SPR_L2CR) & L2CR_L2HWF)
531 			; /* Busy wait for cache to flush */
532 		powerpc_sync();
533 		cache_reg &= ~L2CR_L2E;
534 		mtspr(SPR_L2CR, cache_reg);
535 		powerpc_sync();
536 		mtspr(SPR_L2CR, cache_reg | L2CR_L2I);
537 		powerpc_sync();
538 		while (mfspr(SPR_L2CR) & L2CR_L2I)
539 			; /* Busy wait for L2 cache invalidate */
540 		powerpc_sync();
541 	}
542 
543 	cache_reg = mfspr(SPR_L3CR);
544 	if (cache_reg & L3CR_L3E) {
545 		cache_reg &= ~(L3CR_L3IO | L3CR_L3DO);
546 		mtspr(SPR_L3CR, cache_reg);
547 		powerpc_sync();
548 		mtspr(SPR_L3CR, cache_reg | L3CR_L3HWF);
549 		while (mfspr(SPR_L3CR) & L3CR_L3HWF)
550 			; /* Busy wait for cache to flush */
551 		powerpc_sync();
552 		cache_reg &= ~L3CR_L3E;
553 		mtspr(SPR_L3CR, cache_reg);
554 		powerpc_sync();
555 		mtspr(SPR_L3CR, cache_reg | L3CR_L3I);
556 		powerpc_sync();
557 		while (mfspr(SPR_L3CR) & L3CR_L3I)
558 			; /* Busy wait for L3 cache invalidate */
559 		powerpc_sync();
560 	}
561 
562 	mtspr(SPR_HID0, mfspr(SPR_HID0) & ~HID0_DCE);
563 	powerpc_sync();
564 	isync();
565 
566 	mtmsr(msr);
567 }
568 
569 void
570 cpu_sleep()
571 {
572 	static u_quad_t timebase = 0;
573 	static register_t sprgs[4];
574 	static register_t srrs[2];
575 
576 	jmp_buf resetjb;
577 	struct thread *fputd;
578 	struct thread *vectd;
579 	register_t hid0;
580 	register_t msr;
581 	register_t saved_msr;
582 
583 	ap_pcpu = pcpup;
584 
585 	PCPU_SET(restore, &resetjb);
586 
587 	saved_msr = mfmsr();
588 	fputd = PCPU_GET(fputhread);
589 	vectd = PCPU_GET(vecthread);
590 	if (fputd != NULL)
591 		save_fpu(fputd);
592 	if (vectd != NULL)
593 		save_vec(vectd);
594 	if (setjmp(resetjb) == 0) {
595 		sprgs[0] = mfspr(SPR_SPRG0);
596 		sprgs[1] = mfspr(SPR_SPRG1);
597 		sprgs[2] = mfspr(SPR_SPRG2);
598 		sprgs[3] = mfspr(SPR_SPRG3);
599 		srrs[0] = mfspr(SPR_SRR0);
600 		srrs[1] = mfspr(SPR_SRR1);
601 		timebase = mftb();
602 		powerpc_sync();
603 		flush_disable_caches();
604 		hid0 = mfspr(SPR_HID0);
605 		hid0 = (hid0 & ~(HID0_DOZE | HID0_NAP)) | HID0_SLEEP;
606 		powerpc_sync();
607 		isync();
608 		msr = mfmsr() | PSL_POW;
609 		mtspr(SPR_HID0, hid0);
610 		powerpc_sync();
611 
612 		while (1)
613 			mtmsr(msr);
614 	}
615 	platform_smp_timebase_sync(timebase, 0);
616 	PCPU_SET(curthread, curthread);
617 	PCPU_SET(curpcb, curthread->td_pcb);
618 	pmap_activate(curthread);
619 	powerpc_sync();
620 	mtspr(SPR_SPRG0, sprgs[0]);
621 	mtspr(SPR_SPRG1, sprgs[1]);
622 	mtspr(SPR_SPRG2, sprgs[2]);
623 	mtspr(SPR_SPRG3, sprgs[3]);
624 	mtspr(SPR_SRR0, srrs[0]);
625 	mtspr(SPR_SRR1, srrs[1]);
626 	mtmsr(saved_msr);
627 	if (fputd == curthread)
628 		enable_fpu(curthread);
629 	if (vectd == curthread)
630 		enable_vec(curthread);
631 	powerpc_sync();
632 }
633 
634