1 /*
2  * Common boot and setup code for both 32-bit and 64-bit.
3  * Extracted from arch/powerpc/kernel/setup_64.c.
4  *
5  * Copyright (C) 2001 PPC64 Team, IBM Corp
6  *
7  *      This program is free software; you can redistribute it and/or
8  *      modify it under the terms of the GNU General Public License
9  *      as published by the Free Software Foundation; either version
10  *      2 of the License, or (at your option) any later version.
11  */
12 
13 #undef DEBUG
14 
15 #include <linux/module.h>
16 #include <linux/string.h>
17 #include <linux/sched.h>
18 #include <linux/init.h>
19 #include <linux/kernel.h>
20 #include <linux/reboot.h>
21 #include <linux/delay.h>
22 #include <linux/initrd.h>
23 #include <linux/platform_device.h>
24 #include <linux/seq_file.h>
25 #include <linux/ioport.h>
26 #include <linux/console.h>
27 #include <linux/utsname.h>
28 #include <linux/screen_info.h>
29 #include <linux/root_dev.h>
30 #include <linux/notifier.h>
31 #include <linux/cpu.h>
32 #include <linux/unistd.h>
33 #include <linux/serial.h>
34 #include <linux/serial_8250.h>
35 #include <linux/debugfs.h>
36 #include <linux/percpu.h>
37 #include <linux/lmb.h>
38 #include <linux/of_platform.h>
39 #include <asm/io.h>
40 #include <asm/prom.h>
41 #include <asm/processor.h>
42 #include <asm/vdso_datapage.h>
43 #include <asm/pgtable.h>
44 #include <asm/smp.h>
45 #include <asm/elf.h>
46 #include <asm/machdep.h>
47 #include <asm/time.h>
48 #include <asm/cputable.h>
49 #include <asm/sections.h>
50 #include <asm/firmware.h>
51 #include <asm/btext.h>
52 #include <asm/nvram.h>
53 #include <asm/setup.h>
54 #include <asm/system.h>
55 #include <asm/rtas.h>
56 #include <asm/iommu.h>
57 #include <asm/serial.h>
58 #include <asm/cache.h>
59 #include <asm/page.h>
60 #include <asm/mmu.h>
61 #include <asm/xmon.h>
62 #include <asm/cputhreads.h>
63 #include <mm/mmu_decl.h>
64 
65 #include "setup.h"
66 
67 #ifdef DEBUG
68 #include <asm/udbg.h>
69 #define DBG(fmt...) udbg_printf(fmt)
70 #else
71 #define DBG(fmt...)
72 #endif
73 
74 /* The main machine-dep calls structure
75  */
76 struct machdep_calls ppc_md;
77 EXPORT_SYMBOL(ppc_md);
78 struct machdep_calls *machine_id;
79 EXPORT_SYMBOL(machine_id);
80 
81 unsigned long klimit = (unsigned long) _end;
82 
83 char cmd_line[COMMAND_LINE_SIZE];
84 
85 /*
86  * This still seems to be needed... -- paulus
87  */
88 struct screen_info screen_info = {
89 	.orig_x = 0,
90 	.orig_y = 25,
91 	.orig_video_cols = 80,
92 	.orig_video_lines = 25,
93 	.orig_video_isVGA = 1,
94 	.orig_video_points = 16
95 };
96 
97 #ifdef __DO_IRQ_CANON
98 /* XXX should go elsewhere eventually */
99 int ppc_do_canonicalize_irqs;
100 EXPORT_SYMBOL(ppc_do_canonicalize_irqs);
101 #endif
102 
103 /* also used by kexec */
104 void machine_shutdown(void)
105 {
106 	if (ppc_md.machine_shutdown)
107 		ppc_md.machine_shutdown();
108 }
109 
110 void machine_restart(char *cmd)
111 {
112 	machine_shutdown();
113 	if (ppc_md.restart)
114 		ppc_md.restart(cmd);
115 #ifdef CONFIG_SMP
116 	smp_send_stop();
117 #endif
118 	printk(KERN_EMERG "System Halted, OK to turn off power\n");
119 	local_irq_disable();
120 	while (1) ;
121 }
122 
123 void machine_power_off(void)
124 {
125 	machine_shutdown();
126 	if (ppc_md.power_off)
127 		ppc_md.power_off();
128 #ifdef CONFIG_SMP
129 	smp_send_stop();
130 #endif
131 	printk(KERN_EMERG "System Halted, OK to turn off power\n");
132 	local_irq_disable();
133 	while (1) ;
134 }
135 /* Used by the G5 thermal driver */
136 EXPORT_SYMBOL_GPL(machine_power_off);
137 
138 void (*pm_power_off)(void) = machine_power_off;
139 EXPORT_SYMBOL_GPL(pm_power_off);
140 
141 void machine_halt(void)
142 {
143 	machine_shutdown();
144 	if (ppc_md.halt)
145 		ppc_md.halt();
146 #ifdef CONFIG_SMP
147 	smp_send_stop();
148 #endif
149 	printk(KERN_EMERG "System Halted, OK to turn off power\n");
150 	local_irq_disable();
151 	while (1) ;
152 }
153 
154 
155 #ifdef CONFIG_TAU
156 extern u32 cpu_temp(unsigned long cpu);
157 extern u32 cpu_temp_both(unsigned long cpu);
158 #endif /* CONFIG_TAU */
159 
160 #ifdef CONFIG_SMP
161 DEFINE_PER_CPU(unsigned int, pvr);
162 #endif
163 
164 static int show_cpuinfo(struct seq_file *m, void *v)
165 {
166 	unsigned long cpu_id = (unsigned long)v - 1;
167 	unsigned int pvr;
168 	unsigned short maj;
169 	unsigned short min;
170 
171 	if (cpu_id == NR_CPUS) {
172 		struct device_node *root;
173 		const char *model = NULL;
174 #if defined(CONFIG_SMP) && defined(CONFIG_PPC32)
175 		unsigned long bogosum = 0;
176 		int i;
177 		for_each_online_cpu(i)
178 			bogosum += loops_per_jiffy;
179 		seq_printf(m, "total bogomips\t: %lu.%02lu\n",
180 			   bogosum/(500000/HZ), bogosum/(5000/HZ) % 100);
181 #endif /* CONFIG_SMP && CONFIG_PPC32 */
182 		seq_printf(m, "timebase\t: %lu\n", ppc_tb_freq);
183 		if (ppc_md.name)
184 			seq_printf(m, "platform\t: %s\n", ppc_md.name);
185 		root = of_find_node_by_path("/");
186 		if (root)
187 			model = of_get_property(root, "model", NULL);
188 		if (model)
189 			seq_printf(m, "model\t\t: %s\n", model);
190 		of_node_put(root);
191 
192 		if (ppc_md.show_cpuinfo != NULL)
193 			ppc_md.show_cpuinfo(m);
194 
195 #ifdef CONFIG_PPC32
196 		/* Display the amount of memory */
197 		seq_printf(m, "Memory\t\t: %d MB\n",
198 			   (unsigned int)(total_memory / (1024 * 1024)));
199 #endif
200 
201 		return 0;
202 	}
203 
204 	/* We only show online cpus: disable preempt (overzealous, I
205 	 * knew) to prevent cpu going down. */
206 	preempt_disable();
207 	if (!cpu_online(cpu_id)) {
208 		preempt_enable();
209 		return 0;
210 	}
211 
212 #ifdef CONFIG_SMP
213 	pvr = per_cpu(pvr, cpu_id);
214 #else
215 	pvr = mfspr(SPRN_PVR);
216 #endif
217 	maj = (pvr >> 8) & 0xFF;
218 	min = pvr & 0xFF;
219 
220 	seq_printf(m, "processor\t: %lu\n", cpu_id);
221 	seq_printf(m, "cpu\t\t: ");
222 
223 	if (cur_cpu_spec->pvr_mask)
224 		seq_printf(m, "%s", cur_cpu_spec->cpu_name);
225 	else
226 		seq_printf(m, "unknown (%08x)", pvr);
227 
228 #ifdef CONFIG_ALTIVEC
229 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
230 		seq_printf(m, ", altivec supported");
231 #endif /* CONFIG_ALTIVEC */
232 
233 	seq_printf(m, "\n");
234 
235 #ifdef CONFIG_TAU
236 	if (cur_cpu_spec->cpu_features & CPU_FTR_TAU) {
237 #ifdef CONFIG_TAU_AVERAGE
238 		/* more straightforward, but potentially misleading */
239 		seq_printf(m,  "temperature \t: %u C (uncalibrated)\n",
240 			   cpu_temp(cpu_id));
241 #else
242 		/* show the actual temp sensor range */
243 		u32 temp;
244 		temp = cpu_temp_both(cpu_id);
245 		seq_printf(m, "temperature \t: %u-%u C (uncalibrated)\n",
246 			   temp & 0xff, temp >> 16);
247 #endif
248 	}
249 #endif /* CONFIG_TAU */
250 
251 	/*
252 	 * Assume here that all clock rates are the same in a
253 	 * smp system.  -- Cort
254 	 */
255 	if (ppc_proc_freq)
256 		seq_printf(m, "clock\t\t: %lu.%06luMHz\n",
257 			   ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
258 
259 	if (ppc_md.show_percpuinfo != NULL)
260 		ppc_md.show_percpuinfo(m, cpu_id);
261 
262 	/* If we are a Freescale core do a simple check so
263 	 * we dont have to keep adding cases in the future */
264 	if (PVR_VER(pvr) & 0x8000) {
265 		switch (PVR_VER(pvr)) {
266 		case 0x8000:	/* 7441/7450/7451, Voyager */
267 		case 0x8001:	/* 7445/7455, Apollo 6 */
268 		case 0x8002:	/* 7447/7457, Apollo 7 */
269 		case 0x8003:	/* 7447A, Apollo 7 PM */
270 		case 0x8004:	/* 7448, Apollo 8 */
271 		case 0x800c:	/* 7410, Nitro */
272 			maj = ((pvr >> 8) & 0xF);
273 			min = PVR_MIN(pvr);
274 			break;
275 		default:	/* e500/book-e */
276 			maj = PVR_MAJ(pvr);
277 			min = PVR_MIN(pvr);
278 			break;
279 		}
280 	} else {
281 		switch (PVR_VER(pvr)) {
282 			case 0x0020:	/* 403 family */
283 				maj = PVR_MAJ(pvr) + 1;
284 				min = PVR_MIN(pvr);
285 				break;
286 			case 0x1008:	/* 740P/750P ?? */
287 				maj = ((pvr >> 8) & 0xFF) - 1;
288 				min = pvr & 0xFF;
289 				break;
290 			default:
291 				maj = (pvr >> 8) & 0xFF;
292 				min = pvr & 0xFF;
293 				break;
294 		}
295 	}
296 
297 	seq_printf(m, "revision\t: %hd.%hd (pvr %04x %04x)\n",
298 		   maj, min, PVR_VER(pvr), PVR_REV(pvr));
299 
300 #ifdef CONFIG_PPC32
301 	seq_printf(m, "bogomips\t: %lu.%02lu\n",
302 		   loops_per_jiffy / (500000/HZ),
303 		   (loops_per_jiffy / (5000/HZ)) % 100);
304 #endif
305 
306 #ifdef CONFIG_SMP
307 	seq_printf(m, "\n");
308 #endif
309 
310 	preempt_enable();
311 	return 0;
312 }
313 
314 static void *c_start(struct seq_file *m, loff_t *pos)
315 {
316 	unsigned long i = *pos;
317 
318 	return i <= NR_CPUS ? (void *)(i + 1) : NULL;
319 }
320 
321 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
322 {
323 	++*pos;
324 	return c_start(m, pos);
325 }
326 
327 static void c_stop(struct seq_file *m, void *v)
328 {
329 }
330 
331 struct seq_operations cpuinfo_op = {
332 	.start =c_start,
333 	.next =	c_next,
334 	.stop =	c_stop,
335 	.show =	show_cpuinfo,
336 };
337 
338 void __init check_for_initrd(void)
339 {
340 #ifdef CONFIG_BLK_DEV_INITRD
341 	DBG(" -> check_for_initrd()  initrd_start=0x%lx  initrd_end=0x%lx\n",
342 	    initrd_start, initrd_end);
343 
344 	/* If we were passed an initrd, set the ROOT_DEV properly if the values
345 	 * look sensible. If not, clear initrd reference.
346 	 */
347 	if (is_kernel_addr(initrd_start) && is_kernel_addr(initrd_end) &&
348 	    initrd_end > initrd_start)
349 		ROOT_DEV = Root_RAM0;
350 	else
351 		initrd_start = initrd_end = 0;
352 
353 	if (initrd_start)
354 		printk("Found initrd at 0x%lx:0x%lx\n", initrd_start, initrd_end);
355 
356 	DBG(" <- check_for_initrd()\n");
357 #endif /* CONFIG_BLK_DEV_INITRD */
358 }
359 
360 #ifdef CONFIG_SMP
361 
362 int threads_per_core, threads_shift;
363 cpumask_t threads_core_mask;
364 
365 static void __init cpu_init_thread_core_maps(int tpc)
366 {
367 	int i;
368 
369 	threads_per_core = tpc;
370 	threads_core_mask = CPU_MASK_NONE;
371 
372 	/* This implementation only supports power of 2 number of threads
373 	 * for simplicity and performance
374 	 */
375 	threads_shift = ilog2(tpc);
376 	BUG_ON(tpc != (1 << threads_shift));
377 
378 	for (i = 0; i < tpc; i++)
379 		cpu_set(i, threads_core_mask);
380 
381 	printk(KERN_INFO "CPU maps initialized for %d thread%s per core\n",
382 	       tpc, tpc > 1 ? "s" : "");
383 	printk(KERN_DEBUG " (thread shift is %d)\n", threads_shift);
384 }
385 
386 
387 /**
388  * setup_cpu_maps - initialize the following cpu maps:
389  *                  cpu_possible_map
390  *                  cpu_present_map
391  *
392  * Having the possible map set up early allows us to restrict allocations
393  * of things like irqstacks to num_possible_cpus() rather than NR_CPUS.
394  *
395  * We do not initialize the online map here; cpus set their own bits in
396  * cpu_online_map as they come up.
397  *
398  * This function is valid only for Open Firmware systems.  finish_device_tree
399  * must be called before using this.
400  *
401  * While we're here, we may as well set the "physical" cpu ids in the paca.
402  *
403  * NOTE: This must match the parsing done in early_init_dt_scan_cpus.
404  */
405 void __init smp_setup_cpu_maps(void)
406 {
407 	struct device_node *dn = NULL;
408 	int cpu = 0;
409 	int nthreads = 1;
410 
411 	DBG("smp_setup_cpu_maps()\n");
412 
413 	while ((dn = of_find_node_by_type(dn, "cpu")) && cpu < NR_CPUS) {
414 		const int *intserv;
415 		int j, len;
416 
417 		DBG("  * %s...\n", dn->full_name);
418 
419 		intserv = of_get_property(dn, "ibm,ppc-interrupt-server#s",
420 				&len);
421 		if (intserv) {
422 			nthreads = len / sizeof(int);
423 			DBG("    ibm,ppc-interrupt-server#s -> %d threads\n",
424 			    nthreads);
425 		} else {
426 			DBG("    no ibm,ppc-interrupt-server#s -> 1 thread\n");
427 			intserv = of_get_property(dn, "reg", NULL);
428 			if (!intserv)
429 				intserv = &cpu;	/* assume logical == phys */
430 		}
431 
432 		for (j = 0; j < nthreads && cpu < NR_CPUS; j++) {
433 			DBG("    thread %d -> cpu %d (hard id %d)\n",
434 			    j, cpu, intserv[j]);
435 			cpu_set(cpu, cpu_present_map);
436 			set_hard_smp_processor_id(cpu, intserv[j]);
437 			cpu_set(cpu, cpu_possible_map);
438 			cpu++;
439 		}
440 	}
441 
442 	/* If no SMT supported, nthreads is forced to 1 */
443 	if (!cpu_has_feature(CPU_FTR_SMT)) {
444 		DBG("  SMT disabled ! nthreads forced to 1\n");
445 		nthreads = 1;
446 	}
447 
448 #ifdef CONFIG_PPC64
449 	/*
450 	 * On pSeries LPAR, we need to know how many cpus
451 	 * could possibly be added to this partition.
452 	 */
453 	if (machine_is(pseries) && firmware_has_feature(FW_FEATURE_LPAR) &&
454 	    (dn = of_find_node_by_path("/rtas"))) {
455 		int num_addr_cell, num_size_cell, maxcpus;
456 		const unsigned int *ireg;
457 
458 		num_addr_cell = of_n_addr_cells(dn);
459 		num_size_cell = of_n_size_cells(dn);
460 
461 		ireg = of_get_property(dn, "ibm,lrdr-capacity", NULL);
462 
463 		if (!ireg)
464 			goto out;
465 
466 		maxcpus = ireg[num_addr_cell + num_size_cell];
467 
468 		/* Double maxcpus for processors which have SMT capability */
469 		if (cpu_has_feature(CPU_FTR_SMT))
470 			maxcpus *= nthreads;
471 
472 		if (maxcpus > NR_CPUS) {
473 			printk(KERN_WARNING
474 			       "Partition configured for %d cpus, "
475 			       "operating system maximum is %d.\n",
476 			       maxcpus, NR_CPUS);
477 			maxcpus = NR_CPUS;
478 		} else
479 			printk(KERN_INFO "Partition configured for %d cpus.\n",
480 			       maxcpus);
481 
482 		for (cpu = 0; cpu < maxcpus; cpu++)
483 			cpu_set(cpu, cpu_possible_map);
484 	out:
485 		of_node_put(dn);
486 	}
487 	vdso_data->processorCount = num_present_cpus();
488 #endif /* CONFIG_PPC64 */
489 
490         /* Initialize CPU <=> thread mapping/
491 	 *
492 	 * WARNING: We assume that the number of threads is the same for
493 	 * every CPU in the system. If that is not the case, then some code
494 	 * here will have to be reworked
495 	 */
496 	cpu_init_thread_core_maps(nthreads);
497 }
498 #endif /* CONFIG_SMP */
499 
500 #ifdef CONFIG_PCSPKR_PLATFORM
501 static __init int add_pcspkr(void)
502 {
503 	struct device_node *np;
504 	struct platform_device *pd;
505 	int ret;
506 
507 	np = of_find_compatible_node(NULL, NULL, "pnpPNP,100");
508 	of_node_put(np);
509 	if (!np)
510 		return -ENODEV;
511 
512 	pd = platform_device_alloc("pcspkr", -1);
513 	if (!pd)
514 		return -ENOMEM;
515 
516 	ret = platform_device_add(pd);
517 	if (ret)
518 		platform_device_put(pd);
519 
520 	return ret;
521 }
522 device_initcall(add_pcspkr);
523 #endif	/* CONFIG_PCSPKR_PLATFORM */
524 
525 void probe_machine(void)
526 {
527 	extern struct machdep_calls __machine_desc_start;
528 	extern struct machdep_calls __machine_desc_end;
529 
530 	/*
531 	 * Iterate all ppc_md structures until we find the proper
532 	 * one for the current machine type
533 	 */
534 	DBG("Probing machine type ...\n");
535 
536 	for (machine_id = &__machine_desc_start;
537 	     machine_id < &__machine_desc_end;
538 	     machine_id++) {
539 		DBG("  %s ...", machine_id->name);
540 		memcpy(&ppc_md, machine_id, sizeof(struct machdep_calls));
541 		if (ppc_md.probe()) {
542 			DBG(" match !\n");
543 			break;
544 		}
545 		DBG("\n");
546 	}
547 	/* What can we do if we didn't find ? */
548 	if (machine_id >= &__machine_desc_end) {
549 		DBG("No suitable machine found !\n");
550 		for (;;);
551 	}
552 
553 	printk(KERN_INFO "Using %s machine description\n", ppc_md.name);
554 }
555 
556 /* Match a class of boards, not a specific device configuration. */
557 int check_legacy_ioport(unsigned long base_port)
558 {
559 	struct device_node *parent, *np = NULL;
560 	int ret = -ENODEV;
561 
562 	switch(base_port) {
563 	case I8042_DATA_REG:
564 		if (!(np = of_find_compatible_node(NULL, NULL, "pnpPNP,303")))
565 			np = of_find_compatible_node(NULL, NULL, "pnpPNP,f03");
566 		if (np) {
567 			parent = of_get_parent(np);
568 			of_node_put(np);
569 			np = parent;
570 			break;
571 		}
572 		np = of_find_node_by_type(NULL, "8042");
573 		/* Pegasos has no device_type on its 8042 node, look for the
574 		 * name instead */
575 		if (!np)
576 			np = of_find_node_by_name(NULL, "8042");
577 		break;
578 	case FDC_BASE: /* FDC1 */
579 		np = of_find_node_by_type(NULL, "fdc");
580 		break;
581 #ifdef CONFIG_PPC_PREP
582 	case _PIDXR:
583 	case _PNPWRP:
584 	case PNPBIOS_BASE:
585 		/* implement me */
586 #endif
587 	default:
588 		/* ipmi is supposed to fail here */
589 		break;
590 	}
591 	if (!np)
592 		return ret;
593 	parent = of_get_parent(np);
594 	if (parent) {
595 		if (strcmp(parent->type, "isa") == 0)
596 			ret = 0;
597 		of_node_put(parent);
598 	}
599 	of_node_put(np);
600 	return ret;
601 }
602 EXPORT_SYMBOL(check_legacy_ioport);
603 
604 static int ppc_panic_event(struct notifier_block *this,
605                              unsigned long event, void *ptr)
606 {
607 	ppc_md.panic(ptr);  /* May not return */
608 	return NOTIFY_DONE;
609 }
610 
611 static struct notifier_block ppc_panic_block = {
612 	.notifier_call = ppc_panic_event,
613 	.priority = INT_MIN /* may not return; must be done last */
614 };
615 
616 void __init setup_panic(void)
617 {
618 	atomic_notifier_chain_register(&panic_notifier_list, &ppc_panic_block);
619 }
620 
621 #ifdef CONFIG_CHECK_CACHE_COHERENCY
622 /*
623  * For platforms that have configurable cache-coherency.  This function
624  * checks that the cache coherency setting of the kernel matches the setting
625  * left by the firmware, as indicated in the device tree.  Since a mismatch
626  * will eventually result in DMA failures, we print * and error and call
627  * BUG() in that case.
628  */
629 
630 #ifdef CONFIG_NOT_COHERENT_CACHE
631 #define KERNEL_COHERENCY	0
632 #else
633 #define KERNEL_COHERENCY	1
634 #endif
635 
636 static int __init check_cache_coherency(void)
637 {
638 	struct device_node *np;
639 	const void *prop;
640 	int devtree_coherency;
641 
642 	np = of_find_node_by_path("/");
643 	prop = of_get_property(np, "coherency-off", NULL);
644 	of_node_put(np);
645 
646 	devtree_coherency = prop ? 0 : 1;
647 
648 	if (devtree_coherency != KERNEL_COHERENCY) {
649 		printk(KERN_ERR
650 			"kernel coherency:%s != device tree_coherency:%s\n",
651 			KERNEL_COHERENCY ? "on" : "off",
652 			devtree_coherency ? "on" : "off");
653 		BUG();
654 	}
655 
656 	return 0;
657 }
658 
659 late_initcall(check_cache_coherency);
660 #endif /* CONFIG_CHECK_CACHE_COHERENCY */
661 
662 #ifdef CONFIG_DEBUG_FS
663 struct dentry *powerpc_debugfs_root;
664 
665 static int powerpc_debugfs_init(void)
666 {
667 	powerpc_debugfs_root = debugfs_create_dir("powerpc", NULL);
668 
669 	return powerpc_debugfs_root == NULL;
670 }
671 arch_initcall(powerpc_debugfs_init);
672 #endif
673 
674 static int ppc_dflt_bus_notify(struct notifier_block *nb,
675 				unsigned long action, void *data)
676 {
677 	struct device *dev = data;
678 
679 	/* We are only intereted in device addition */
680 	if (action != BUS_NOTIFY_ADD_DEVICE)
681 		return 0;
682 
683 	set_dma_ops(dev, &dma_direct_ops);
684 
685 	return NOTIFY_DONE;
686 }
687 
688 static struct notifier_block ppc_dflt_plat_bus_notifier = {
689 	.notifier_call = ppc_dflt_bus_notify,
690 	.priority = INT_MAX,
691 };
692 
693 static struct notifier_block ppc_dflt_of_bus_notifier = {
694 	.notifier_call = ppc_dflt_bus_notify,
695 	.priority = INT_MAX,
696 };
697 
698 static int __init setup_bus_notifier(void)
699 {
700 	bus_register_notifier(&platform_bus_type, &ppc_dflt_plat_bus_notifier);
701 	bus_register_notifier(&of_platform_bus_type, &ppc_dflt_of_bus_notifier);
702 
703 	return 0;
704 }
705 
706 arch_initcall(setup_bus_notifier);
707