summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/kernel/misc_64.S
blob: 32be2a844947436662b48e034ff42a2cad6fc3d9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
/*
 * This file contains miscellaneous low-level functions.
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
 * and Paul Mackerras.
 * Adapted for iSeries by Mike Corrigan (mikejc@us.ibm.com)
 * PPC64 updates by Dave Engebretsen (engebret@us.ibm.com)
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 *
 */

#include <linux/sys.h>
#include <asm/unistd.h>
#include <asm/errno.h>
#include <asm/processor.h>
#include <asm/page.h>
#include <asm/cache.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/cputable.h>
#include <asm/thread_info.h>
#include <asm/kexec.h>
#include <asm/ptrace.h>
#include <asm/mmu.h>
#include <asm/export.h>

	.text

_GLOBAL(call_do_softirq)
	mflr	r0
	std	r0,16(r1)
	stdu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
	mr	r1,r3
	bl	__do_softirq
	ld	r1,0(r1)
	ld	r0,16(r1)
	mtlr	r0
	blr

_GLOBAL(call_do_irq)
	mflr	r0
	std	r0,16(r1)
	stdu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r4)
	mr	r1,r4
	bl	__do_irq
	ld	r1,0(r1)
	ld	r0,16(r1)
	mtlr	r0
	blr

	.section	".toc","aw"
PPC64_CACHES:
	.tc		ppc64_caches[TC],ppc64_caches
	.section	".text"

/*
 * Write any modified data cache blocks out to memory
 * and invalidate the corresponding instruction cache blocks.
 *
 * flush_icache_range(unsigned long start, unsigned long stop)
 *
 *   flush all bytes from start through stop-1 inclusive
 */

_GLOBAL(flush_icache_range)
BEGIN_FTR_SECTION
	PURGE_PREFETCHED_INS
	blr
END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
/*
 * Flush the data cache to memory 
 * 
 * Different systems have different cache line sizes
 * and in some cases i-cache and d-cache line sizes differ from
 * each other.
 */
 	ld	r10,PPC64_CACHES@toc(r2)
	lwz	r7,DCACHEL1LINESIZE(r10)/* Get cache line size */
	addi	r5,r7,-1
	andc	r6,r3,r5		/* round low to line bdy */
	subf	r8,r6,r4		/* compute length */
	add	r8,r8,r5		/* ensure we get enough */
	lwz	r9,DCACHEL1LOGLINESIZE(r10)	/* Get log-2 of cache line size */
	srw.	r8,r8,r9		/* compute line count */
	beqlr				/* nothing to do? */
	mtctr	r8
1:	dcbst	0,r6
	add	r6,r6,r7
	bdnz	1b
	sync

/* Now invalidate the instruction cache */
	
	lwz	r7,ICACHEL1LINESIZE(r10)	/* Get Icache line size */
	addi	r5,r7,-1
	andc	r6,r3,r5		/* round low to line bdy */
	subf	r8,r6,r4		/* compute length */
	add	r8,r8,r5
	lwz	r9,ICACHEL1LOGLINESIZE(r10)	/* Get log-2 of Icache line size */
	srw.	r8,r8,r9		/* compute line count */
	beqlr				/* nothing to do? */
	mtctr	r8
2:	icbi	0,r6
	add	r6,r6,r7
	bdnz	2b
	isync
	blr
_ASM_NOKPROBE_SYMBOL(flush_icache_range)
EXPORT_SYMBOL(flush_icache_range)

/*
 * Like above, but only do the D-cache.
 *
 * flush_dcache_range(unsigned long start, unsigned long stop)
 *
 *    flush all bytes from start to stop-1 inclusive
 */
_GLOBAL(flush_dcache_range)

/*
 * Flush the data cache to memory 
 * 
 * Different systems have different cache line sizes
 */
 	ld	r10,PPC64_CACHES@toc(r2)
	lwz	r7,DCACHEL1LINESIZE(r10)	/* Get dcache line size */
	addi	r5,r7,-1
	andc	r6,r3,r5		/* round low to line bdy */
	subf	r8,r6,r4		/* compute length */
	add	r8,r8,r5		/* ensure we get enough */
	lwz	r9,DCACHEL1LOGLINESIZE(r10)	/* Get log-2 of dcache line size */
	srw.	r8,r8,r9		/* compute line count */
	beqlr				/* nothing to do? */
	mtctr	r8
0:	dcbst	0,r6
	add	r6,r6,r7
	bdnz	0b
	sync
	blr
EXPORT_SYMBOL(flush_dcache_range)

/*
 * Like above, but works on non-mapped physical addresses.
 * Use only for non-LPAR setups ! It also assumes real mode
 * is cacheable. Used for flushing out the DART before using
 * it as uncacheable memory 
 *
 * flush_dcache_phys_range(unsigned long start, unsigned long stop)
 *
 *    flush all bytes from start to stop-1 inclusive
 */
_GLOBAL(flush_dcache_phys_range)
 	ld	r10,PPC64_CACHES@toc(r2)
	lwz	r7,DCACHEL1LINESIZE(r10)	/* Get dcache line size */
	addi	r5,r7,-1
	andc	r6,r3,r5		/* round low to line bdy */
	subf	r8,r6,r4		/* compute length */
	add	r8,r8,r5		/* ensure we get enough */
	lwz	r9,DCACHEL1LOGLINESIZE(r10)	/* Get log-2 of dcache line size */
	srw.	r8,r8,r9		/* compute line count */
	beqlr				/* nothing to do? */
	mfmsr	r5			/* Disable MMU Data Relocation */
	ori	r0,r5,MSR_DR
	xori	r0,r0,MSR_DR
	sync
	mtmsr	r0
	sync
	isync
	mtctr	r8
0:	dcbst	0,r6
	add	r6,r6,r7
	bdnz	0b
	sync
	isync
	mtmsr	r5			/* Re-enable MMU Data Relocation */
	sync
	isync
	blr

_GLOBAL(flush_inval_dcache_range)
 	ld	r10,PPC64_CACHES@toc(r2)
	lwz	r7,DCACHEL1LINESIZE(r10)	/* Get dcache line size */
	addi	r5,r7,-1
	andc	r6,r3,r5		/* round low to line bdy */
	subf	r8,r6,r4		/* compute length */
	add	r8,r8,r5		/* ensure we get enough */
	lwz	r9,DCACHEL1LOGLINESIZE(r10)/* Get log-2 of dcache line size */
	srw.	r8,r8,r9		/* compute line count */
	beqlr				/* nothing to do? */
	sync
	isync
	mtctr	r8
0:	dcbf	0,r6
	add	r6,r6,r7
	bdnz	0b
	sync
	isync
	blr


/*
 * Flush a particular page from the data cache to RAM.
 * Note: this is necessary because the instruction cache does *not*
 * snoop from the data cache.
 *
 *	void __flush_dcache_icache(void *page)
 */
_GLOBAL(__flush_dcache_icache)
/*
 * Flush the data cache to memory 
 * 
 * Different systems have different cache line sizes
 */

BEGIN_FTR_SECTION
	PURGE_PREFETCHED_INS
	blr
END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)

/* Flush the dcache */
 	ld	r7,PPC64_CACHES@toc(r2)
	clrrdi	r3,r3,PAGE_SHIFT           	    /* Page align */
	lwz	r4,DCACHEL1LINESPERPAGE(r7)	/* Get # dcache lines per page */
	lwz	r5,DCACHEL1LINESIZE(r7)		/* Get dcache line size */
	mr	r6,r3
	mtctr	r4
0:	dcbst	0,r6
	add	r6,r6,r5
	bdnz	0b
	sync

/* Now invalidate the icache */	

	lwz	r4,ICACHEL1LINESPERPAGE(r7)	/* Get # icache lines per page */
	lwz	r5,ICACHEL1LINESIZE(r7)		/* Get icache line size */
	mtctr	r4
1:	icbi	0,r3
	add	r3,r3,r5
	bdnz	1b
	isync
	blr

_GLOBAL(__bswapdi2)
EXPORT_SYMBOL(__bswapdi2)
	srdi	r8,r3,32
	rlwinm	r7,r3,8,0xffffffff
	rlwimi	r7,r3,24,0,7
	rlwinm	r9,r8,8,0xffffffff
	rlwimi	r7,r3,24,16,23
	rlwimi	r9,r8,24,0,7
	rlwimi	r9,r8,24,16,23
	sldi	r7,r7,32
	or	r3,r7,r9
	blr


#ifdef CONFIG_PPC_EARLY_DEBUG_BOOTX
_GLOBAL(rmci_on)
	sync
	isync
	li	r3,0x100
	rldicl	r3,r3,32,0
	mfspr	r5,SPRN_HID4
	or	r5,r5,r3
	sync
	mtspr	SPRN_HID4,r5
	isync
	slbia
	isync
	sync
	blr

_GLOBAL(rmci_off)
	sync
	isync
	li	r3,0x100
	rldicl	r3,r3,32,0
	mfspr	r5,SPRN_HID4
	andc	r5,r5,r3
	sync
	mtspr	SPRN_HID4,r5
	isync
	slbia
	isync
	sync
	blr
#endif /* CONFIG_PPC_EARLY_DEBUG_BOOTX */

#if defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE)

/*
 * Do an IO access in real mode
 */
_GLOBAL(real_readb)
	mfmsr	r7
	ori	r0,r7,MSR_DR
	xori	r0,r0,MSR_DR
	sync
	mtmsrd	r0
	sync
	isync
	mfspr	r6,SPRN_HID4
	rldicl	r5,r6,32,0
	ori	r5,r5,0x100
	rldicl	r5,r5,32,0
	sync
	mtspr	SPRN_HID4,r5
	isync
	slbia
	isync
	lbz	r3,0(r3)
	sync
	mtspr	SPRN_HID4,r6
	isync
	slbia
	isync
	mtmsrd	r7
	sync
	isync
	blr

	/*
 * Do an IO access in real mode
 */
_GLOBAL(real_writeb)
	mfmsr	r7
	ori	r0,r7,MSR_DR
	xori	r0,r0,MSR_DR
	sync
	mtmsrd	r0
	sync
	isync
	mfspr	r6,SPRN_HID4
	rldicl	r5,r6,32,0
	ori	r5,r5,0x100
	rldicl	r5,r5,32,0
	sync
	mtspr	SPRN_HID4,r5
	isync
	slbia
	isync
	stb	r3,0(r4)
	sync
	mtspr	SPRN_HID4,r6
	isync
	slbia
	isync
	mtmsrd	r7
	sync
	isync
	blr
#endif /* defined(CONFIG_PPC_PMAC) || defined(CONFIG_PPC_MAPLE) */

#ifdef CONFIG_PPC_PASEMI

_GLOBAL(real_205_readb)
	mfmsr	r7
	ori	r0,r7,MSR_DR
	xori	r0,r0,MSR_DR
	sync
	mtmsrd	r0
	sync
	isync
	LBZCIX(R3,R0,R3)
	isync
	mtmsrd	r7
	sync
	isync
	blr

_GLOBAL(real_205_writeb)
	mfmsr	r7
	ori	r0,r7,MSR_DR
	xori	r0,r0,MSR_DR
	sync
	mtmsrd	r0
	sync
	isync
	STBCIX(R3,R0,R4)
	isync
	mtmsrd	r7
	sync
	isync
	blr

#endif /* CONFIG_PPC_PASEMI */


#if defined(CONFIG_CPU_FREQ_PMAC64) || defined(CONFIG_CPU_FREQ_MAPLE)
/*
 * SCOM access functions for 970 (FX only for now)
 *
 * unsigned long scom970_read(unsigned int address);
 * void scom970_write(unsigned int address, unsigned long value);
 *
 * The address passed in is the 24 bits register address. This code
 * is 970 specific and will not check the status bits, so you should
 * know what you are doing.
 */
_GLOBAL(scom970_read)
	/* interrupts off */
	mfmsr	r4
	ori	r0,r4,MSR_EE
	xori	r0,r0,MSR_EE
	mtmsrd	r0,1

	/* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
	 * (including parity). On current CPUs they must be 0'd,
	 * and finally or in RW bit
	 */
	rlwinm	r3,r3,8,0,15
	ori	r3,r3,0x8000

	/* do the actual scom read */
	sync
	mtspr	SPRN_SCOMC,r3
	isync
	mfspr	r3,SPRN_SCOMD
	isync
	mfspr	r0,SPRN_SCOMC
	isync

	/* XXX:	fixup result on some buggy 970's (ouch ! we lost a bit, bah
	 * that's the best we can do). Not implemented yet as we don't use
	 * the scom on any of the bogus CPUs yet, but may have to be done
	 * ultimately
	 */

	/* restore interrupts */
	mtmsrd	r4,1
	blr


_GLOBAL(scom970_write)
	/* interrupts off */
	mfmsr	r5
	ori	r0,r5,MSR_EE
	xori	r0,r0,MSR_EE
	mtmsrd	r0,1

	/* rotate 24 bits SCOM address 8 bits left and mask out it's low 8 bits
	 * (including parity). On current CPUs they must be 0'd.
	 */

	rlwinm	r3,r3,8,0,15

	sync
	mtspr	SPRN_SCOMD,r4      /* write data */
	isync
	mtspr	SPRN_SCOMC,r3      /* write command */
	isync
	mfspr	3,SPRN_SCOMC
	isync

	/* restore interrupts */
	mtmsrd	r5,1
	blr
#endif /* CONFIG_CPU_FREQ_PMAC64 || CONFIG_CPU_FREQ_MAPLE */

/* kexec_wait(phys_cpu)
 *
 * wait for the flag to change, indicating this kernel is going away but
 * the slave code for the next one is at addresses 0 to 100.
 *
 * This is used by all slaves, even those that did not find a matching
 * paca in the secondary startup code.
 *
 * Physical (hardware) cpu id should be in r3.
 */
_GLOBAL(kexec_wait)
	bl	1f
1:	mflr	r5
	addi	r5,r5,kexec_flag-1b

99:	HMT_LOW
#ifdef CONFIG_KEXEC_CORE	/* use no memory without kexec */
	lwz	r4,0(r5)
	cmpwi	0,r4,0
	beq	99b
#ifdef CONFIG_PPC_BOOK3S_64
	li	r10,0x60
	mfmsr	r11
	clrrdi	r11,r11,1	/* Clear MSR_LE */
	mtsrr0	r10
	mtsrr1	r11
	rfid
#else
	/* Create TLB entry in book3e_secondary_core_init */
	li	r4,0
	ba	0x60
#endif
#endif

/* this can be in text because we won't change it until we are
 * running in real anyways
 */
kexec_flag:
	.long	0


#ifdef CONFIG_KEXEC_CORE
#ifdef CONFIG_PPC_BOOK3E
/*
 * BOOK3E has no real MMU mode, so we have to setup the initial TLB
 * for a core to identity map v:0 to p:0.  This current implementation
 * assumes that 1G is enough for kexec.
 */
kexec_create_tlb:
	/*
	 * Invalidate all non-IPROT TLB entries to avoid any TLB conflict.
	 * IPROT TLB entries should be >= PAGE_OFFSET and thus not conflict.
	 */
	PPC_TLBILX_ALL(0,R0)
	sync
	isync

	mfspr	r10,SPRN_TLB1CFG
	andi.	r10,r10,TLBnCFG_N_ENTRY	/* Extract # entries */
	subi	r10,r10,1	/* Last entry: no conflict with kernel text */
	lis	r9,MAS0_TLBSEL(1)@h
	rlwimi	r9,r10,16,4,15		/* Setup MAS0 = TLBSEL | ESEL(r9) */

/* Set up a temp identity mapping v:0 to p:0 and return to it. */
#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC)
#define M_IF_NEEDED	MAS2_M
#else
#define M_IF_NEEDED	0
#endif
	mtspr	SPRN_MAS0,r9

	lis	r9,(MAS1_VALID|MAS1_IPROT)@h
	ori	r9,r9,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l
	mtspr	SPRN_MAS1,r9

	LOAD_REG_IMMEDIATE(r9, 0x0 | M_IF_NEEDED)
	mtspr	SPRN_MAS2,r9

	LOAD_REG_IMMEDIATE(r9, 0x0 | MAS3_SR | MAS3_SW | MAS3_SX)
	mtspr	SPRN_MAS3,r9
	li	r9,0
	mtspr	SPRN_MAS7,r9

	tlbwe
	isync
	blr
#endif

/* kexec_smp_wait(void)
 *
 * call with interrupts off
 * note: this is a terminal routine, it does not save lr
 *
 * get phys id from paca
 * switch to real mode
 * mark the paca as no longer used
 * join other cpus in kexec_wait(phys_id)
 */
_GLOBAL(kexec_smp_wait)
	lhz	r3,PACAHWCPUID(r13)
	bl	real_mode

	li	r4,KEXEC_STATE_REAL_MODE
	stb	r4,PACAKEXECSTATE(r13)
	SYNC

	b	kexec_wait

/*
 * switch to real mode (turn mmu off)
 * we use the early kernel trick that the hardware ignores bits
 * 0 and 1 (big endian) of the effective address in real mode
 *
 * don't overwrite r3 here, it is live for kexec_wait above.
 */
real_mode:	/* assume normal blr return */
#ifdef CONFIG_PPC_BOOK3E
	/* Create an identity mapping. */
	b	kexec_create_tlb
#else
1:	li	r9,MSR_RI
	li	r10,MSR_DR|MSR_IR
	mflr	r11		/* return address to SRR0 */
	mfmsr	r12
	andc	r9,r12,r9
	andc	r10,r12,r10

	mtmsrd	r9,1
	mtspr	SPRN_SRR1,r10
	mtspr	SPRN_SRR0,r11
	rfid
#endif

/*
 * kexec_sequence(newstack, start, image, control, clear_all(),
	          copy_with_mmu_off)
 *
 * does the grungy work with stack switching and real mode switches
 * also does simple calls to other code
 */

_GLOBAL(kexec_sequence)
	mflr	r0
	std	r0,16(r1)

	/* switch stacks to newstack -- &kexec_stack.stack */
	stdu	r1,THREAD_SIZE-STACK_FRAME_OVERHEAD(r3)
	mr	r1,r3

	li	r0,0
	std	r0,16(r1)

	/* save regs for local vars on new stack.
	 * yes, we won't go back, but ...
	 */
	std	r31,-8(r1)
	std	r30,-16(r1)
	std	r29,-24(r1)
	std	r28,-32(r1)
	std	r27,-40(r1)
	std	r26,-48(r1)
	std	r25,-56(r1)

	stdu	r1,-STACK_FRAME_OVERHEAD-64(r1)

	/* save args into preserved regs */
	mr	r31,r3			/* newstack (both) */
	mr	r30,r4			/* start (real) */
	mr	r29,r5			/* image (virt) */
	mr	r28,r6			/* control, unused */
	mr	r27,r7			/* clear_all() fn desc */
	mr	r26,r8			/* copy_with_mmu_off */
	lhz	r25,PACAHWCPUID(r13)	/* get our phys cpu from paca */

	/* disable interrupts, we are overwriting kernel data next */
#ifdef CONFIG_PPC_BOOK3E
	wrteei	0
#else
	mfmsr	r3
	rlwinm	r3,r3,0,17,15
	mtmsrd	r3,1
#endif

	/* We need to turn the MMU off unless we are in hash mode
	 * under a hypervisor
	 */
	cmpdi	r26,0
	beq	1f
	bl	real_mode
1:
	/* copy dest pages, flush whole dest image */
	mr	r3,r29
	bl	kexec_copy_flush	/* (image) */

	/* turn off mmu now if not done earlier */
	cmpdi	r26,0
	bne	1f
	bl	real_mode

	/* copy  0x100 bytes starting at start to 0 */
1:	li	r3,0
	mr	r4,r30		/* start, aka phys mem offset */
	li	r5,0x100
	li	r6,0
	bl	copy_and_flush	/* (dest, src, copy limit, start offset) */
1:	/* assume normal blr return */

	/* release other cpus to the new kernel secondary start at 0x60 */
	mflr	r5
	li	r6,1
	stw	r6,kexec_flag-1b(5)

	cmpdi	r27,0
	beq	1f

	/* clear out hardware hash page table and tlb */
#ifdef PPC64_ELF_ABI_v1
	ld	r12,0(r27)		/* deref function descriptor */
#else
	mr	r12,r27
#endif
	mtctr	r12
	bctrl				/* mmu_hash_ops.hpte_clear_all(void); */

/*
 *   kexec image calling is:
 *      the first 0x100 bytes of the entry point are copied to 0
 *
 *      all slaves branch to slave = 0x60 (absolute)
 *              slave(phys_cpu_id);
 *
 *      master goes to start = entry point
 *              start(phys_cpu_id, start, 0);
 *
 *
 *   a wrapper is needed to call existing kernels, here is an approximate
 *   description of one method:
 *
 * v2: (2.6.10)
 *   start will be near the boot_block (maybe 0x100 bytes before it?)
 *   it will have a 0x60, which will b to boot_block, where it will wait
 *   and 0 will store phys into struct boot-block and load r3 from there,
 *   copy kernel 0-0x100 and tell slaves to back down to 0x60 again
 *
 * v1: (2.6.9)
 *    boot block will have all cpus scanning device tree to see if they
 *    are the boot cpu ?????
 *    other device tree differences (prop sizes, va vs pa, etc)...
 */
1:	mr	r3,r25	# my phys cpu
	mr	r4,r30	# start, aka phys mem offset
	mtlr	4
	li	r5,0
	blr	/* image->start(physid, image->start, 0); */
#endif /* CONFIG_KEXEC_CORE */