xref: /linux/arch/powerpc/platforms/powermac/smp.c (revision 906fd46a65383cd639e5eec72a047efc33045d86)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * SMP support for power macintosh.
4  *
5  * We support both the old "powersurge" SMP architecture
6  * and the current Core99 (G4 PowerMac) machines.
7  *
8  * Note that we don't support the very first rev. of
9  * Apple/DayStar 2 CPUs board, the one with the funky
10  * watchdog. Hopefully, none of these should be there except
11  * maybe internally to Apple. I should probably still add some
12  * code to detect this card though and disable SMP. --BenH.
13  *
14  * Support Macintosh G4 SMP by Troy Benjegerdes (hozer@drgw.net)
15  * and Ben Herrenschmidt <benh@kernel.crashing.org>.
16  *
17  * Support for DayStar quad CPU cards
18  * Copyright (C) XLR8, Inc. 1994-2000
19  */
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/sched/hotplug.h>
23 #include <linux/smp.h>
24 #include <linux/interrupt.h>
25 #include <linux/irqdomain.h>
26 #include <linux/kernel_stat.h>
27 #include <linux/delay.h>
28 #include <linux/init.h>
29 #include <linux/spinlock.h>
30 #include <linux/errno.h>
31 #include <linux/hardirq.h>
32 #include <linux/cpu.h>
33 #include <linux/compiler.h>
34 #include <linux/pgtable.h>
35 
36 #include <asm/ptrace.h>
37 #include <linux/atomic.h>
38 #include <asm/code-patching.h>
39 #include <asm/irq.h>
40 #include <asm/page.h>
41 #include <asm/sections.h>
42 #include <asm/io.h>
43 #include <asm/smp.h>
44 #include <asm/machdep.h>
45 #include <asm/pmac_feature.h>
46 #include <asm/time.h>
47 #include <asm/mpic.h>
48 #include <asm/cacheflush.h>
49 #include <asm/keylargo.h>
50 #include <asm/pmac_low_i2c.h>
51 #include <asm/pmac_pfunc.h>
52 #include <asm/inst.h>
53 
54 #include "pmac.h"
55 
56 #undef DEBUG
57 
58 #ifdef DEBUG
59 #define DBG(fmt...) udbg_printf(fmt)
60 #else
61 #define DBG(fmt...)
62 #endif
63 
64 extern void __secondary_start_pmac_0(void);
65 
66 static void (*pmac_tb_freeze)(int freeze);
67 static u64 timebase;
68 static int tb_req;
69 
70 #ifdef CONFIG_PPC_PMAC32_PSURGE
71 
72 /*
73  * Powersurge (old powermac SMP) support.
74  */
75 
76 /* Addresses for powersurge registers */
77 #define HAMMERHEAD_BASE		0xf8000000
78 #define HHEAD_CONFIG		0x90
79 #define HHEAD_SEC_INTR		0xc0
80 
81 /* register for interrupting the primary processor on the powersurge */
82 /* N.B. this is actually the ethernet ROM! */
83 #define PSURGE_PRI_INTR		0xf3019000
84 
85 /* register for storing the start address for the secondary processor */
86 /* N.B. this is the PCI config space address register for the 1st bridge */
87 #define PSURGE_START		0xf2800000
88 
89 /* Daystar/XLR8 4-CPU card */
90 #define PSURGE_QUAD_REG_ADDR	0xf8800000
91 
92 #define PSURGE_QUAD_IRQ_SET	0
93 #define PSURGE_QUAD_IRQ_CLR	1
94 #define PSURGE_QUAD_IRQ_PRIMARY	2
95 #define PSURGE_QUAD_CKSTOP_CTL	3
96 #define PSURGE_QUAD_PRIMARY_ARB	4
97 #define PSURGE_QUAD_BOARD_ID	6
98 #define PSURGE_QUAD_WHICH_CPU	7
99 #define PSURGE_QUAD_CKSTOP_RDBK	8
100 #define PSURGE_QUAD_RESET_CTL	11
101 
102 #define PSURGE_QUAD_OUT(r, v)	(out_8(quad_base + ((r) << 4) + 4, (v)))
103 #define PSURGE_QUAD_IN(r)	(in_8(quad_base + ((r) << 4) + 4) & 0x0f)
104 #define PSURGE_QUAD_BIS(r, v)	(PSURGE_QUAD_OUT((r), PSURGE_QUAD_IN(r) | (v)))
105 #define PSURGE_QUAD_BIC(r, v)	(PSURGE_QUAD_OUT((r), PSURGE_QUAD_IN(r) & ~(v)))
106 
107 /* virtual addresses for the above */
108 static volatile u8 __iomem *hhead_base;
109 static volatile u8 __iomem *quad_base;
110 static volatile u32 __iomem *psurge_pri_intr;
111 static volatile u8 __iomem *psurge_sec_intr;
112 static volatile u32 __iomem *psurge_start;
113 
114 /* values for psurge_type */
115 #define PSURGE_NONE		-1
116 #define PSURGE_DUAL		0
117 #define PSURGE_QUAD_OKEE	1
118 #define PSURGE_QUAD_COTTON	2
119 #define PSURGE_QUAD_ICEGRASS	3
120 
121 /* what sort of powersurge board we have */
122 static int psurge_type = PSURGE_NONE;
123 
124 /* irq for secondary cpus to report */
125 static struct irq_domain *psurge_host;
126 int psurge_secondary_virq;
127 
128 /*
129  * Set and clear IPIs for powersurge.
130  */
131 static inline void psurge_set_ipi(int cpu)
132 {
133 	if (psurge_type == PSURGE_NONE)
134 		return;
135 	if (cpu == 0)
136 		in_be32(psurge_pri_intr);
137 	else if (psurge_type == PSURGE_DUAL)
138 		out_8(psurge_sec_intr, 0);
139 	else
140 		PSURGE_QUAD_OUT(PSURGE_QUAD_IRQ_SET, 1 << cpu);
141 }
142 
143 static inline void psurge_clr_ipi(int cpu)
144 {
145 	if (cpu > 0) {
146 		switch(psurge_type) {
147 		case PSURGE_DUAL:
148 			out_8(psurge_sec_intr, ~0);
149 			break;
150 		case PSURGE_NONE:
151 			break;
152 		default:
153 			PSURGE_QUAD_OUT(PSURGE_QUAD_IRQ_CLR, 1 << cpu);
154 		}
155 	}
156 }
157 
158 /*
159  * On powersurge (old SMP powermac architecture) we don't have
160  * separate IPIs for separate messages like openpic does.  Instead
161  * use the generic demux helpers
162  *  -- paulus.
163  */
164 static irqreturn_t psurge_ipi_intr(int irq, void *d)
165 {
166 	psurge_clr_ipi(smp_processor_id());
167 	smp_ipi_demux();
168 
169 	return IRQ_HANDLED;
170 }
171 
172 static void smp_psurge_cause_ipi(int cpu)
173 {
174 	psurge_set_ipi(cpu);
175 }
176 
177 static int psurge_host_map(struct irq_domain *h, unsigned int virq,
178 			 irq_hw_number_t hw)
179 {
180 	irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_percpu_irq);
181 
182 	return 0;
183 }
184 
185 static const struct irq_domain_ops psurge_host_ops = {
186 	.map	= psurge_host_map,
187 };
188 
189 static int __init psurge_secondary_ipi_init(void)
190 {
191 	int rc = -ENOMEM;
192 
193 	psurge_host = irq_domain_add_nomap(NULL, ~0, &psurge_host_ops, NULL);
194 
195 	if (psurge_host)
196 		psurge_secondary_virq = irq_create_direct_mapping(psurge_host);
197 
198 	if (psurge_secondary_virq)
199 		rc = request_irq(psurge_secondary_virq, psurge_ipi_intr,
200 			IRQF_PERCPU | IRQF_NO_THREAD, "IPI", NULL);
201 
202 	if (rc)
203 		pr_err("Failed to setup secondary cpu IPI\n");
204 
205 	return rc;
206 }
207 
208 /*
209  * Determine a quad card presence. We read the board ID register, we
210  * force the data bus to change to something else, and we read it again.
211  * It it's stable, then the register probably exist (ugh !)
212  */
213 static int __init psurge_quad_probe(void)
214 {
215 	int type;
216 	unsigned int i;
217 
218 	type = PSURGE_QUAD_IN(PSURGE_QUAD_BOARD_ID);
219 	if (type < PSURGE_QUAD_OKEE || type > PSURGE_QUAD_ICEGRASS
220 	    || type != PSURGE_QUAD_IN(PSURGE_QUAD_BOARD_ID))
221 		return PSURGE_DUAL;
222 
223 	/* looks OK, try a slightly more rigorous test */
224 	/* bogus is not necessarily cacheline-aligned,
225 	   though I don't suppose that really matters.  -- paulus */
226 	for (i = 0; i < 100; i++) {
227 		volatile u32 bogus[8];
228 		bogus[(0+i)%8] = 0x00000000;
229 		bogus[(1+i)%8] = 0x55555555;
230 		bogus[(2+i)%8] = 0xFFFFFFFF;
231 		bogus[(3+i)%8] = 0xAAAAAAAA;
232 		bogus[(4+i)%8] = 0x33333333;
233 		bogus[(5+i)%8] = 0xCCCCCCCC;
234 		bogus[(6+i)%8] = 0xCCCCCCCC;
235 		bogus[(7+i)%8] = 0x33333333;
236 		wmb();
237 		asm volatile("dcbf 0,%0" : : "r" (bogus) : "memory");
238 		mb();
239 		if (type != PSURGE_QUAD_IN(PSURGE_QUAD_BOARD_ID))
240 			return PSURGE_DUAL;
241 	}
242 	return type;
243 }
244 
245 static void __init psurge_quad_init(void)
246 {
247 	int procbits;
248 
249 	if (ppc_md.progress) ppc_md.progress("psurge_quad_init", 0x351);
250 	procbits = ~PSURGE_QUAD_IN(PSURGE_QUAD_WHICH_CPU);
251 	if (psurge_type == PSURGE_QUAD_ICEGRASS)
252 		PSURGE_QUAD_BIS(PSURGE_QUAD_RESET_CTL, procbits);
253 	else
254 		PSURGE_QUAD_BIC(PSURGE_QUAD_CKSTOP_CTL, procbits);
255 	mdelay(33);
256 	out_8(psurge_sec_intr, ~0);
257 	PSURGE_QUAD_OUT(PSURGE_QUAD_IRQ_CLR, procbits);
258 	PSURGE_QUAD_BIS(PSURGE_QUAD_RESET_CTL, procbits);
259 	if (psurge_type != PSURGE_QUAD_ICEGRASS)
260 		PSURGE_QUAD_BIS(PSURGE_QUAD_CKSTOP_CTL, procbits);
261 	PSURGE_QUAD_BIC(PSURGE_QUAD_PRIMARY_ARB, procbits);
262 	mdelay(33);
263 	PSURGE_QUAD_BIC(PSURGE_QUAD_RESET_CTL, procbits);
264 	mdelay(33);
265 	PSURGE_QUAD_BIS(PSURGE_QUAD_PRIMARY_ARB, procbits);
266 	mdelay(33);
267 }
268 
269 static void __init smp_psurge_probe(void)
270 {
271 	int i, ncpus;
272 	struct device_node *dn;
273 
274 	/*
275 	 * The powersurge cpu board can be used in the generation
276 	 * of powermacs that have a socket for an upgradeable cpu card,
277 	 * including the 7500, 8500, 9500, 9600.
278 	 * The device tree doesn't tell you if you have 2 cpus because
279 	 * OF doesn't know anything about the 2nd processor.
280 	 * Instead we look for magic bits in magic registers,
281 	 * in the hammerhead memory controller in the case of the
282 	 * dual-cpu powersurge board.  -- paulus.
283 	 */
284 	dn = of_find_node_by_name(NULL, "hammerhead");
285 	if (dn == NULL)
286 		return;
287 	of_node_put(dn);
288 
289 	hhead_base = ioremap(HAMMERHEAD_BASE, 0x800);
290 	quad_base = ioremap(PSURGE_QUAD_REG_ADDR, 1024);
291 	psurge_sec_intr = hhead_base + HHEAD_SEC_INTR;
292 
293 	psurge_type = psurge_quad_probe();
294 	if (psurge_type != PSURGE_DUAL) {
295 		psurge_quad_init();
296 		/* All released cards using this HW design have 4 CPUs */
297 		ncpus = 4;
298 		/* No sure how timebase sync works on those, let's use SW */
299 		smp_ops->give_timebase = smp_generic_give_timebase;
300 		smp_ops->take_timebase = smp_generic_take_timebase;
301 	} else {
302 		iounmap(quad_base);
303 		if ((in_8(hhead_base + HHEAD_CONFIG) & 0x02) == 0) {
304 			/* not a dual-cpu card */
305 			iounmap(hhead_base);
306 			psurge_type = PSURGE_NONE;
307 			return;
308 		}
309 		ncpus = 2;
310 	}
311 
312 	if (psurge_secondary_ipi_init())
313 		return;
314 
315 	psurge_start = ioremap(PSURGE_START, 4);
316 	psurge_pri_intr = ioremap(PSURGE_PRI_INTR, 4);
317 
318 	/* This is necessary because OF doesn't know about the
319 	 * secondary cpu(s), and thus there aren't nodes in the
320 	 * device tree for them, and smp_setup_cpu_maps hasn't
321 	 * set their bits in cpu_present_mask.
322 	 */
323 	if (ncpus > NR_CPUS)
324 		ncpus = NR_CPUS;
325 	for (i = 1; i < ncpus ; ++i)
326 		set_cpu_present(i, true);
327 
328 	if (ppc_md.progress) ppc_md.progress("smp_psurge_probe - done", 0x352);
329 }
330 
331 static int __init smp_psurge_kick_cpu(int nr)
332 {
333 	unsigned long start = __pa(__secondary_start_pmac_0) + nr * 8;
334 	unsigned long a, flags;
335 	int i, j;
336 
337 	/* Defining this here is evil ... but I prefer hiding that
338 	 * crap to avoid giving people ideas that they can do the
339 	 * same.
340 	 */
341 	extern volatile unsigned int cpu_callin_map[NR_CPUS];
342 
343 	/* may need to flush here if secondary bats aren't setup */
344 	for (a = KERNELBASE; a < KERNELBASE + 0x800000; a += 32)
345 		asm volatile("dcbf 0,%0" : : "r" (a) : "memory");
346 	asm volatile("sync");
347 
348 	if (ppc_md.progress) ppc_md.progress("smp_psurge_kick_cpu", 0x353);
349 
350 	/* This is going to freeze the timeebase, we disable interrupts */
351 	local_irq_save(flags);
352 
353 	out_be32(psurge_start, start);
354 	mb();
355 
356 	psurge_set_ipi(nr);
357 
358 	/*
359 	 * We can't use udelay here because the timebase is now frozen.
360 	 */
361 	for (i = 0; i < 2000; ++i)
362 		asm volatile("nop" : : : "memory");
363 	psurge_clr_ipi(nr);
364 
365 	/*
366 	 * Also, because the timebase is frozen, we must not return to the
367 	 * caller which will try to do udelay's etc... Instead, we wait -here-
368 	 * for the CPU to callin.
369 	 */
370 	for (i = 0; i < 100000 && !cpu_callin_map[nr]; ++i) {
371 		for (j = 1; j < 10000; j++)
372 			asm volatile("nop" : : : "memory");
373 		asm volatile("sync" : : : "memory");
374 	}
375 	if (!cpu_callin_map[nr])
376 		goto stuck;
377 
378 	/* And we do the TB sync here too for standard dual CPU cards */
379 	if (psurge_type == PSURGE_DUAL) {
380 		while(!tb_req)
381 			barrier();
382 		tb_req = 0;
383 		mb();
384 		timebase = get_tb();
385 		mb();
386 		while (timebase)
387 			barrier();
388 		mb();
389 	}
390  stuck:
391 	/* now interrupt the secondary, restarting both TBs */
392 	if (psurge_type == PSURGE_DUAL)
393 		psurge_set_ipi(1);
394 
395 	if (ppc_md.progress) ppc_md.progress("smp_psurge_kick_cpu - done", 0x354);
396 
397 	return 0;
398 }
399 
400 static void __init smp_psurge_setup_cpu(int cpu_nr)
401 {
402 	unsigned long flags = IRQF_PERCPU | IRQF_NO_THREAD;
403 	int irq;
404 
405 	if (cpu_nr != 0 || !psurge_start)
406 		return;
407 
408 	/* reset the entry point so if we get another intr we won't
409 	 * try to startup again */
410 	out_be32(psurge_start, 0x100);
411 	irq = irq_create_mapping(NULL, 30);
412 	if (request_irq(irq, psurge_ipi_intr, flags, "primary IPI", NULL))
413 		printk(KERN_ERR "Couldn't get primary IPI interrupt");
414 }
415 
416 static void __init smp_psurge_take_timebase(void)
417 {
418 	if (psurge_type != PSURGE_DUAL)
419 		return;
420 
421 	tb_req = 1;
422 	mb();
423 	while (!timebase)
424 		barrier();
425 	mb();
426 	set_tb(timebase >> 32, timebase & 0xffffffff);
427 	timebase = 0;
428 	mb();
429 	set_dec(tb_ticks_per_jiffy/2);
430 }
431 
432 static void __init smp_psurge_give_timebase(void)
433 {
434 	/* Nothing to do here */
435 }
436 
437 /* PowerSurge-style Macs */
438 struct smp_ops_t psurge_smp_ops = {
439 	.message_pass	= NULL,	/* Use smp_muxed_ipi_message_pass */
440 	.cause_ipi	= smp_psurge_cause_ipi,
441 	.cause_nmi_ipi	= NULL,
442 	.probe		= smp_psurge_probe,
443 	.kick_cpu	= smp_psurge_kick_cpu,
444 	.setup_cpu	= smp_psurge_setup_cpu,
445 	.give_timebase	= smp_psurge_give_timebase,
446 	.take_timebase	= smp_psurge_take_timebase,
447 };
448 #endif /* CONFIG_PPC_PMAC32_PSURGE */
449 
450 /*
451  * Core 99 and later support
452  */
453 
454 
455 static void smp_core99_give_timebase(void)
456 {
457 	unsigned long flags;
458 
459 	local_irq_save(flags);
460 
461 	while(!tb_req)
462 		barrier();
463 	tb_req = 0;
464 	(*pmac_tb_freeze)(1);
465 	mb();
466 	timebase = get_tb();
467 	mb();
468 	while (timebase)
469 		barrier();
470 	mb();
471 	(*pmac_tb_freeze)(0);
472 	mb();
473 
474 	local_irq_restore(flags);
475 }
476 
477 
478 static void smp_core99_take_timebase(void)
479 {
480 	unsigned long flags;
481 
482 	local_irq_save(flags);
483 
484 	tb_req = 1;
485 	mb();
486 	while (!timebase)
487 		barrier();
488 	mb();
489 	set_tb(timebase >> 32, timebase & 0xffffffff);
490 	timebase = 0;
491 	mb();
492 
493 	local_irq_restore(flags);
494 }
495 
496 #ifdef CONFIG_PPC64
497 /*
498  * G5s enable/disable the timebase via an i2c-connected clock chip.
499  */
500 static struct pmac_i2c_bus *pmac_tb_clock_chip_host;
501 static u8 pmac_tb_pulsar_addr;
502 
503 static void smp_core99_cypress_tb_freeze(int freeze)
504 {
505 	u8 data;
506 	int rc;
507 
508 	/* Strangely, the device-tree says address is 0xd2, but darwin
509 	 * accesses 0xd0 ...
510 	 */
511 	pmac_i2c_setmode(pmac_tb_clock_chip_host,
512 			 pmac_i2c_mode_combined);
513 	rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
514 			   0xd0 | pmac_i2c_read,
515 			   1, 0x81, &data, 1);
516 	if (rc != 0)
517 		goto bail;
518 
519 	data = (data & 0xf3) | (freeze ? 0x00 : 0x0c);
520 
521        	pmac_i2c_setmode(pmac_tb_clock_chip_host, pmac_i2c_mode_stdsub);
522 	rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
523 			   0xd0 | pmac_i2c_write,
524 			   1, 0x81, &data, 1);
525 
526  bail:
527 	if (rc != 0) {
528 		printk("Cypress Timebase %s rc: %d\n",
529 		       freeze ? "freeze" : "unfreeze", rc);
530 		panic("Timebase freeze failed !\n");
531 	}
532 }
533 
534 
535 static void smp_core99_pulsar_tb_freeze(int freeze)
536 {
537 	u8 data;
538 	int rc;
539 
540 	pmac_i2c_setmode(pmac_tb_clock_chip_host,
541 			 pmac_i2c_mode_combined);
542 	rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
543 			   pmac_tb_pulsar_addr | pmac_i2c_read,
544 			   1, 0x2e, &data, 1);
545 	if (rc != 0)
546 		goto bail;
547 
548 	data = (data & 0x88) | (freeze ? 0x11 : 0x22);
549 
550 	pmac_i2c_setmode(pmac_tb_clock_chip_host, pmac_i2c_mode_stdsub);
551 	rc = pmac_i2c_xfer(pmac_tb_clock_chip_host,
552 			   pmac_tb_pulsar_addr | pmac_i2c_write,
553 			   1, 0x2e, &data, 1);
554  bail:
555 	if (rc != 0) {
556 		printk(KERN_ERR "Pulsar Timebase %s rc: %d\n",
557 		       freeze ? "freeze" : "unfreeze", rc);
558 		panic("Timebase freeze failed !\n");
559 	}
560 }
561 
562 static void __init smp_core99_setup_i2c_hwsync(int ncpus)
563 {
564 	struct device_node *cc = NULL;
565 	struct device_node *p;
566 	const char *name = NULL;
567 	const u32 *reg;
568 	int ok;
569 
570 	/* Look for the clock chip */
571 	for_each_node_by_name(cc, "i2c-hwclock") {
572 		p = of_get_parent(cc);
573 		ok = p && of_device_is_compatible(p, "uni-n-i2c");
574 		of_node_put(p);
575 		if (!ok)
576 			continue;
577 
578 		pmac_tb_clock_chip_host = pmac_i2c_find_bus(cc);
579 		if (pmac_tb_clock_chip_host == NULL)
580 			continue;
581 		reg = of_get_property(cc, "reg", NULL);
582 		if (reg == NULL)
583 			continue;
584 		switch (*reg) {
585 		case 0xd2:
586 			if (of_device_is_compatible(cc,"pulsar-legacy-slewing")) {
587 				pmac_tb_freeze = smp_core99_pulsar_tb_freeze;
588 				pmac_tb_pulsar_addr = 0xd2;
589 				name = "Pulsar";
590 			} else if (of_device_is_compatible(cc, "cy28508")) {
591 				pmac_tb_freeze = smp_core99_cypress_tb_freeze;
592 				name = "Cypress";
593 			}
594 			break;
595 		case 0xd4:
596 			pmac_tb_freeze = smp_core99_pulsar_tb_freeze;
597 			pmac_tb_pulsar_addr = 0xd4;
598 			name = "Pulsar";
599 			break;
600 		}
601 		if (pmac_tb_freeze != NULL) {
602 			of_node_put(cc);
603 			break;
604 		}
605 	}
606 	if (pmac_tb_freeze != NULL) {
607 		/* Open i2c bus for synchronous access */
608 		if (pmac_i2c_open(pmac_tb_clock_chip_host, 1)) {
609 			printk(KERN_ERR "Failed top open i2c bus for clock"
610 			       " sync, fallback to software sync !\n");
611 			goto no_i2c_sync;
612 		}
613 		printk(KERN_INFO "Processor timebase sync using %s i2c clock\n",
614 		       name);
615 		return;
616 	}
617  no_i2c_sync:
618 	pmac_tb_freeze = NULL;
619 	pmac_tb_clock_chip_host = NULL;
620 }
621 
622 
623 
624 /*
625  * Newer G5s uses a platform function
626  */
627 
628 static void smp_core99_pfunc_tb_freeze(int freeze)
629 {
630 	struct device_node *cpus;
631 	struct pmf_args args;
632 
633 	cpus = of_find_node_by_path("/cpus");
634 	BUG_ON(cpus == NULL);
635 	args.count = 1;
636 	args.u[0].v = !freeze;
637 	pmf_call_function(cpus, "cpu-timebase", &args);
638 	of_node_put(cpus);
639 }
640 
641 #else /* CONFIG_PPC64 */
642 
643 /*
644  * SMP G4 use a GPIO to enable/disable the timebase.
645  */
646 
647 static unsigned int core99_tb_gpio;	/* Timebase freeze GPIO */
648 
649 static void smp_core99_gpio_tb_freeze(int freeze)
650 {
651 	if (freeze)
652 		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, core99_tb_gpio, 4);
653 	else
654 		pmac_call_feature(PMAC_FTR_WRITE_GPIO, NULL, core99_tb_gpio, 0);
655 	pmac_call_feature(PMAC_FTR_READ_GPIO, NULL, core99_tb_gpio, 0);
656 }
657 
658 
659 #endif /* !CONFIG_PPC64 */
660 
661 static void core99_init_caches(int cpu)
662 {
663 #ifndef CONFIG_PPC64
664 	/* L2 and L3 cache settings to pass from CPU0 to CPU1 on G4 cpus */
665 	static long int core99_l2_cache;
666 	static long int core99_l3_cache;
667 
668 	if (!cpu_has_feature(CPU_FTR_L2CR))
669 		return;
670 
671 	if (cpu == 0) {
672 		core99_l2_cache = _get_L2CR();
673 		printk("CPU0: L2CR is %lx\n", core99_l2_cache);
674 	} else {
675 		printk("CPU%d: L2CR was %lx\n", cpu, _get_L2CR());
676 		_set_L2CR(0);
677 		_set_L2CR(core99_l2_cache);
678 		printk("CPU%d: L2CR set to %lx\n", cpu, core99_l2_cache);
679 	}
680 
681 	if (!cpu_has_feature(CPU_FTR_L3CR))
682 		return;
683 
684 	if (cpu == 0){
685 		core99_l3_cache = _get_L3CR();
686 		printk("CPU0: L3CR is %lx\n", core99_l3_cache);
687 	} else {
688 		printk("CPU%d: L3CR was %lx\n", cpu, _get_L3CR());
689 		_set_L3CR(0);
690 		_set_L3CR(core99_l3_cache);
691 		printk("CPU%d: L3CR set to %lx\n", cpu, core99_l3_cache);
692 	}
693 #endif /* !CONFIG_PPC64 */
694 }
695 
696 static void __init smp_core99_setup(int ncpus)
697 {
698 #ifdef CONFIG_PPC64
699 
700 	/* i2c based HW sync on some G5s */
701 	if (of_machine_is_compatible("PowerMac7,2") ||
702 	    of_machine_is_compatible("PowerMac7,3") ||
703 	    of_machine_is_compatible("RackMac3,1"))
704 		smp_core99_setup_i2c_hwsync(ncpus);
705 
706 	/* pfunc based HW sync on recent G5s */
707 	if (pmac_tb_freeze == NULL) {
708 		struct device_node *cpus =
709 			of_find_node_by_path("/cpus");
710 		if (cpus &&
711 		    of_property_read_bool(cpus, "platform-cpu-timebase")) {
712 			pmac_tb_freeze = smp_core99_pfunc_tb_freeze;
713 			printk(KERN_INFO "Processor timebase sync using"
714 			       " platform function\n");
715 		}
716 		of_node_put(cpus);
717 	}
718 
719 #else /* CONFIG_PPC64 */
720 
721 	/* GPIO based HW sync on ppc32 Core99 */
722 	if (pmac_tb_freeze == NULL && !of_machine_is_compatible("MacRISC4")) {
723 		struct device_node *cpu;
724 		const u32 *tbprop = NULL;
725 
726 		core99_tb_gpio = KL_GPIO_TB_ENABLE;	/* default value */
727 		cpu = of_find_node_by_type(NULL, "cpu");
728 		if (cpu != NULL) {
729 			tbprop = of_get_property(cpu, "timebase-enable", NULL);
730 			if (tbprop)
731 				core99_tb_gpio = *tbprop;
732 			of_node_put(cpu);
733 		}
734 		pmac_tb_freeze = smp_core99_gpio_tb_freeze;
735 		printk(KERN_INFO "Processor timebase sync using"
736 		       " GPIO 0x%02x\n", core99_tb_gpio);
737 	}
738 
739 #endif /* CONFIG_PPC64 */
740 
741 	/* No timebase sync, fallback to software */
742 	if (pmac_tb_freeze == NULL) {
743 		smp_ops->give_timebase = smp_generic_give_timebase;
744 		smp_ops->take_timebase = smp_generic_take_timebase;
745 		printk(KERN_INFO "Processor timebase sync using software\n");
746 	}
747 
748 #ifndef CONFIG_PPC64
749 	{
750 		int i;
751 
752 		/* XXX should get this from reg properties */
753 		for (i = 1; i < ncpus; ++i)
754 			set_hard_smp_processor_id(i, i);
755 	}
756 #endif
757 
758 	/* 32 bits SMP can't NAP */
759 	if (!of_machine_is_compatible("MacRISC4"))
760 		powersave_nap = 0;
761 }
762 
763 static void __init smp_core99_probe(void)
764 {
765 	struct device_node *cpus;
766 	int ncpus = 0;
767 
768 	if (ppc_md.progress) ppc_md.progress("smp_core99_probe", 0x345);
769 
770 	/* Count CPUs in the device-tree */
771 	for_each_node_by_type(cpus, "cpu")
772 		++ncpus;
773 
774 	printk(KERN_INFO "PowerMac SMP probe found %d cpus\n", ncpus);
775 
776 	/* Nothing more to do if less than 2 of them */
777 	if (ncpus <= 1)
778 		return;
779 
780 	/* We need to perform some early initialisations before we can start
781 	 * setting up SMP as we are running before initcalls
782 	 */
783 	pmac_pfunc_base_install();
784 	pmac_i2c_init();
785 
786 	/* Setup various bits like timebase sync method, ability to nap, ... */
787 	smp_core99_setup(ncpus);
788 
789 	/* Install IPIs */
790 	mpic_request_ipis();
791 
792 	/* Collect l2cr and l3cr values from CPU 0 */
793 	core99_init_caches(0);
794 }
795 
796 static int smp_core99_kick_cpu(int nr)
797 {
798 	unsigned int save_vector;
799 	unsigned long target, flags;
800 	unsigned int *vector = (unsigned int *)(PAGE_OFFSET+0x100);
801 
802 	if (nr < 0 || nr > 3)
803 		return -ENOENT;
804 
805 	if (ppc_md.progress)
806 		ppc_md.progress("smp_core99_kick_cpu", 0x346);
807 
808 	local_irq_save(flags);
809 
810 	/* Save reset vector */
811 	save_vector = *vector;
812 
813 	/* Setup fake reset vector that does
814 	 *   b __secondary_start_pmac_0 + nr*8
815 	 */
816 	target = (unsigned long) __secondary_start_pmac_0 + nr * 8;
817 	patch_branch(vector, target, BRANCH_SET_LINK);
818 
819 	/* Put some life in our friend */
820 	pmac_call_feature(PMAC_FTR_RESET_CPU, NULL, nr, 0);
821 
822 	/* FIXME: We wait a bit for the CPU to take the exception, I should
823 	 * instead wait for the entry code to set something for me. Well,
824 	 * ideally, all that crap will be done in prom.c and the CPU left
825 	 * in a RAM-based wait loop like CHRP.
826 	 */
827 	mdelay(1);
828 
829 	/* Restore our exception vector */
830 	patch_instruction(vector, ppc_inst(save_vector));
831 
832 	local_irq_restore(flags);
833 	if (ppc_md.progress) ppc_md.progress("smp_core99_kick_cpu done", 0x347);
834 
835 	return 0;
836 }
837 
838 static void smp_core99_setup_cpu(int cpu_nr)
839 {
840 	/* Setup L2/L3 */
841 	if (cpu_nr != 0)
842 		core99_init_caches(cpu_nr);
843 
844 	/* Setup openpic */
845 	mpic_setup_this_cpu();
846 }
847 
848 #ifdef CONFIG_PPC64
849 #ifdef CONFIG_HOTPLUG_CPU
850 static unsigned int smp_core99_host_open;
851 
852 static int smp_core99_cpu_prepare(unsigned int cpu)
853 {
854 	int rc;
855 
856 	/* Open i2c bus if it was used for tb sync */
857 	if (pmac_tb_clock_chip_host && !smp_core99_host_open) {
858 		rc = pmac_i2c_open(pmac_tb_clock_chip_host, 1);
859 		if (rc) {
860 			pr_err("Failed to open i2c bus for time sync\n");
861 			return notifier_from_errno(rc);
862 		}
863 		smp_core99_host_open = 1;
864 	}
865 	return 0;
866 }
867 
868 static int smp_core99_cpu_online(unsigned int cpu)
869 {
870 	/* Close i2c bus if it was used for tb sync */
871 	if (pmac_tb_clock_chip_host && smp_core99_host_open) {
872 		pmac_i2c_close(pmac_tb_clock_chip_host);
873 		smp_core99_host_open = 0;
874 	}
875 	return 0;
876 }
877 #endif /* CONFIG_HOTPLUG_CPU */
878 
879 static void __init smp_core99_bringup_done(void)
880 {
881 	/* Close i2c bus if it was used for tb sync */
882 	if (pmac_tb_clock_chip_host)
883 		pmac_i2c_close(pmac_tb_clock_chip_host);
884 
885 	/* If we didn't start the second CPU, we must take
886 	 * it off the bus.
887 	 */
888 	if (of_machine_is_compatible("MacRISC4") &&
889 	    num_online_cpus() < 2) {
890 		set_cpu_present(1, false);
891 		g5_phy_disable_cpu1();
892 	}
893 #ifdef CONFIG_HOTPLUG_CPU
894 	cpuhp_setup_state_nocalls(CPUHP_POWERPC_PMAC_PREPARE,
895 				  "powerpc/pmac:prepare", smp_core99_cpu_prepare,
896 				  NULL);
897 	cpuhp_setup_state_nocalls(CPUHP_AP_ONLINE_DYN, "powerpc/pmac:online",
898 				  smp_core99_cpu_online, NULL);
899 #endif
900 
901 	if (ppc_md.progress)
902 		ppc_md.progress("smp_core99_bringup_done", 0x349);
903 }
904 #endif /* CONFIG_PPC64 */
905 
906 #ifdef CONFIG_HOTPLUG_CPU
907 
908 static int smp_core99_cpu_disable(void)
909 {
910 	int rc = generic_cpu_disable();
911 	if (rc)
912 		return rc;
913 
914 	mpic_cpu_set_priority(0xf);
915 
916 	cleanup_cpu_mmu_context();
917 
918 	return 0;
919 }
920 
921 #ifdef CONFIG_PPC32
922 
923 static void pmac_cpu_offline_self(void)
924 {
925 	int cpu = smp_processor_id();
926 
927 	local_irq_disable();
928 	idle_task_exit();
929 	pr_debug("CPU%d offline\n", cpu);
930 	generic_set_cpu_dead(cpu);
931 	smp_wmb();
932 	mb();
933 	low_cpu_offline_self();
934 }
935 
936 #else /* CONFIG_PPC32 */
937 
938 static void pmac_cpu_offline_self(void)
939 {
940 	int cpu = smp_processor_id();
941 
942 	local_irq_disable();
943 	idle_task_exit();
944 
945 	/*
946 	 * turn off as much as possible, we'll be
947 	 * kicked out as this will only be invoked
948 	 * on core99 platforms for now ...
949 	 */
950 
951 	printk(KERN_INFO "CPU#%d offline\n", cpu);
952 	generic_set_cpu_dead(cpu);
953 	smp_wmb();
954 
955 	/*
956 	 * Re-enable interrupts. The NAP code needs to enable them
957 	 * anyways, do it now so we deal with the case where one already
958 	 * happened while soft-disabled.
959 	 * We shouldn't get any external interrupts, only decrementer, and the
960 	 * decrementer handler is safe for use on offline CPUs
961 	 */
962 	local_irq_enable();
963 
964 	while (1) {
965 		/* let's not take timer interrupts too often ... */
966 		set_dec(0x7fffffff);
967 
968 		/* Enter NAP mode */
969 		power4_idle();
970 	}
971 }
972 
973 #endif /* else CONFIG_PPC32 */
974 #endif /* CONFIG_HOTPLUG_CPU */
975 
976 /* Core99 Macs (dual G4s and G5s) */
977 static struct smp_ops_t core99_smp_ops = {
978 	.message_pass	= smp_mpic_message_pass,
979 	.probe		= smp_core99_probe,
980 #ifdef CONFIG_PPC64
981 	.bringup_done	= smp_core99_bringup_done,
982 #endif
983 	.kick_cpu	= smp_core99_kick_cpu,
984 	.setup_cpu	= smp_core99_setup_cpu,
985 	.give_timebase	= smp_core99_give_timebase,
986 	.take_timebase	= smp_core99_take_timebase,
987 #if defined(CONFIG_HOTPLUG_CPU)
988 	.cpu_disable	= smp_core99_cpu_disable,
989 	.cpu_die	= generic_cpu_die,
990 #endif
991 };
992 
993 void __init pmac_setup_smp(void)
994 {
995 	struct device_node *np;
996 
997 	/* Check for Core99 */
998 	np = of_find_node_by_name(NULL, "uni-n");
999 	if (!np)
1000 		np = of_find_node_by_name(NULL, "u3");
1001 	if (!np)
1002 		np = of_find_node_by_name(NULL, "u4");
1003 	if (np) {
1004 		of_node_put(np);
1005 		smp_ops = &core99_smp_ops;
1006 	}
1007 #ifdef CONFIG_PPC_PMAC32_PSURGE
1008 	else {
1009 		/* We have to set bits in cpu_possible_mask here since the
1010 		 * secondary CPU(s) aren't in the device tree. Various
1011 		 * things won't be initialized for CPUs not in the possible
1012 		 * map, so we really need to fix it up here.
1013 		 */
1014 		int cpu;
1015 
1016 		for (cpu = 1; cpu < 4 && cpu < NR_CPUS; ++cpu)
1017 			set_cpu_possible(cpu, true);
1018 		smp_ops = &psurge_smp_ops;
1019 	}
1020 #endif /* CONFIG_PPC_PMAC32_PSURGE */
1021 
1022 #ifdef CONFIG_HOTPLUG_CPU
1023 	smp_ops->cpu_offline_self = pmac_cpu_offline_self;
1024 #endif
1025 }
1026 
1027 
1028