xref: /openbmc/linux/arch/x86/kernel/mpparse.c (revision fd589a8f)
1 /*
2  *	Intel Multiprocessor Specification 1.1 and 1.4
3  *	compliant MP-table parsing routines.
4  *
5  *	(c) 1995 Alan Cox, Building #3 <alan@lxorguk.ukuu.org.uk>
6  *	(c) 1998, 1999, 2000, 2009 Ingo Molnar <mingo@redhat.com>
7  *      (c) 2008 Alexey Starikovskiy <astarikovskiy@suse.de>
8  */
9 
10 #include <linux/mm.h>
11 #include <linux/init.h>
12 #include <linux/delay.h>
13 #include <linux/bootmem.h>
14 #include <linux/kernel_stat.h>
15 #include <linux/mc146818rtc.h>
16 #include <linux/bitops.h>
17 #include <linux/acpi.h>
18 #include <linux/module.h>
19 #include <linux/smp.h>
20 #include <linux/pci.h>
21 
22 #include <asm/mtrr.h>
23 #include <asm/mpspec.h>
24 #include <asm/pgalloc.h>
25 #include <asm/io_apic.h>
26 #include <asm/proto.h>
27 #include <asm/bios_ebda.h>
28 #include <asm/e820.h>
29 #include <asm/trampoline.h>
30 #include <asm/setup.h>
31 #include <asm/smp.h>
32 
33 #include <asm/apic.h>
34 /*
35  * Checksum an MP configuration block.
36  */
37 
38 static int __init mpf_checksum(unsigned char *mp, int len)
39 {
40 	int sum = 0;
41 
42 	while (len--)
43 		sum += *mp++;
44 
45 	return sum & 0xFF;
46 }
47 
48 int __init default_mpc_apic_id(struct mpc_cpu *m)
49 {
50 	return m->apicid;
51 }
52 
53 static void __init MP_processor_info(struct mpc_cpu *m)
54 {
55 	int apicid;
56 	char *bootup_cpu = "";
57 
58 	if (!(m->cpuflag & CPU_ENABLED)) {
59 		disabled_cpus++;
60 		return;
61 	}
62 
63 	apicid = x86_init.mpparse.mpc_apic_id(m);
64 
65 	if (m->cpuflag & CPU_BOOTPROCESSOR) {
66 		bootup_cpu = " (Bootup-CPU)";
67 		boot_cpu_physical_apicid = m->apicid;
68 	}
69 
70 	printk(KERN_INFO "Processor #%d%s\n", m->apicid, bootup_cpu);
71 	generic_processor_info(apicid, m->apicver);
72 }
73 
74 #ifdef CONFIG_X86_IO_APIC
75 void __init default_mpc_oem_bus_info(struct mpc_bus *m, char *str)
76 {
77 	memcpy(str, m->bustype, 6);
78 	str[6] = 0;
79 	apic_printk(APIC_VERBOSE, "Bus #%d is %s\n", m->busid, str);
80 }
81 
82 static void __init MP_bus_info(struct mpc_bus *m)
83 {
84 	char str[7];
85 
86 	x86_init.mpparse.mpc_oem_bus_info(m, str);
87 
88 #if MAX_MP_BUSSES < 256
89 	if (m->busid >= MAX_MP_BUSSES) {
90 		printk(KERN_WARNING "MP table busid value (%d) for bustype %s "
91 		       " is too large, max. supported is %d\n",
92 		       m->busid, str, MAX_MP_BUSSES - 1);
93 		return;
94 	}
95 #endif
96 
97 	if (strncmp(str, BUSTYPE_ISA, sizeof(BUSTYPE_ISA) - 1) == 0) {
98 		set_bit(m->busid, mp_bus_not_pci);
99 #if defined(CONFIG_EISA) || defined(CONFIG_MCA)
100 		mp_bus_id_to_type[m->busid] = MP_BUS_ISA;
101 #endif
102 	} else if (strncmp(str, BUSTYPE_PCI, sizeof(BUSTYPE_PCI) - 1) == 0) {
103 		if (x86_init.mpparse.mpc_oem_pci_bus)
104 			x86_init.mpparse.mpc_oem_pci_bus(m);
105 
106 		clear_bit(m->busid, mp_bus_not_pci);
107 #if defined(CONFIG_EISA) || defined(CONFIG_MCA)
108 		mp_bus_id_to_type[m->busid] = MP_BUS_PCI;
109 	} else if (strncmp(str, BUSTYPE_EISA, sizeof(BUSTYPE_EISA) - 1) == 0) {
110 		mp_bus_id_to_type[m->busid] = MP_BUS_EISA;
111 	} else if (strncmp(str, BUSTYPE_MCA, sizeof(BUSTYPE_MCA) - 1) == 0) {
112 		mp_bus_id_to_type[m->busid] = MP_BUS_MCA;
113 #endif
114 	} else
115 		printk(KERN_WARNING "Unknown bustype %s - ignoring\n", str);
116 }
117 
118 static int bad_ioapic(unsigned long address)
119 {
120 	if (nr_ioapics >= MAX_IO_APICS) {
121 		printk(KERN_ERR "ERROR: Max # of I/O APICs (%d) exceeded "
122 		       "(found %d)\n", MAX_IO_APICS, nr_ioapics);
123 		panic("Recompile kernel with bigger MAX_IO_APICS!\n");
124 	}
125 	if (!address) {
126 		printk(KERN_ERR "WARNING: Bogus (zero) I/O APIC address"
127 		       " found in table, skipping!\n");
128 		return 1;
129 	}
130 	return 0;
131 }
132 
133 static void __init MP_ioapic_info(struct mpc_ioapic *m)
134 {
135 	if (!(m->flags & MPC_APIC_USABLE))
136 		return;
137 
138 	printk(KERN_INFO "I/O APIC #%d Version %d at 0x%X.\n",
139 	       m->apicid, m->apicver, m->apicaddr);
140 
141 	if (bad_ioapic(m->apicaddr))
142 		return;
143 
144 	mp_ioapics[nr_ioapics].apicaddr = m->apicaddr;
145 	mp_ioapics[nr_ioapics].apicid = m->apicid;
146 	mp_ioapics[nr_ioapics].type = m->type;
147 	mp_ioapics[nr_ioapics].apicver = m->apicver;
148 	mp_ioapics[nr_ioapics].flags = m->flags;
149 	nr_ioapics++;
150 }
151 
152 static void print_MP_intsrc_info(struct mpc_intsrc *m)
153 {
154 	apic_printk(APIC_VERBOSE, "Int: type %d, pol %d, trig %d, bus %02x,"
155 		" IRQ %02x, APIC ID %x, APIC INT %02x\n",
156 		m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbus,
157 		m->srcbusirq, m->dstapic, m->dstirq);
158 }
159 
160 static void __init print_mp_irq_info(struct mpc_intsrc *mp_irq)
161 {
162 	apic_printk(APIC_VERBOSE, "Int: type %d, pol %d, trig %d, bus %02x,"
163 		" IRQ %02x, APIC ID %x, APIC INT %02x\n",
164 		mp_irq->irqtype, mp_irq->irqflag & 3,
165 		(mp_irq->irqflag >> 2) & 3, mp_irq->srcbus,
166 		mp_irq->srcbusirq, mp_irq->dstapic, mp_irq->dstirq);
167 }
168 
169 static void __init assign_to_mp_irq(struct mpc_intsrc *m,
170 				    struct mpc_intsrc *mp_irq)
171 {
172 	mp_irq->dstapic = m->dstapic;
173 	mp_irq->type = m->type;
174 	mp_irq->irqtype = m->irqtype;
175 	mp_irq->irqflag = m->irqflag;
176 	mp_irq->srcbus = m->srcbus;
177 	mp_irq->srcbusirq = m->srcbusirq;
178 	mp_irq->dstirq = m->dstirq;
179 }
180 
181 static void __init assign_to_mpc_intsrc(struct mpc_intsrc *mp_irq,
182 					struct mpc_intsrc *m)
183 {
184 	m->dstapic = mp_irq->dstapic;
185 	m->type = mp_irq->type;
186 	m->irqtype = mp_irq->irqtype;
187 	m->irqflag = mp_irq->irqflag;
188 	m->srcbus = mp_irq->srcbus;
189 	m->srcbusirq = mp_irq->srcbusirq;
190 	m->dstirq = mp_irq->dstirq;
191 }
192 
193 static int __init mp_irq_mpc_intsrc_cmp(struct mpc_intsrc *mp_irq,
194 					struct mpc_intsrc *m)
195 {
196 	if (mp_irq->dstapic != m->dstapic)
197 		return 1;
198 	if (mp_irq->type != m->type)
199 		return 2;
200 	if (mp_irq->irqtype != m->irqtype)
201 		return 3;
202 	if (mp_irq->irqflag != m->irqflag)
203 		return 4;
204 	if (mp_irq->srcbus != m->srcbus)
205 		return 5;
206 	if (mp_irq->srcbusirq != m->srcbusirq)
207 		return 6;
208 	if (mp_irq->dstirq != m->dstirq)
209 		return 7;
210 
211 	return 0;
212 }
213 
214 static void __init MP_intsrc_info(struct mpc_intsrc *m)
215 {
216 	int i;
217 
218 	print_MP_intsrc_info(m);
219 
220 	for (i = 0; i < mp_irq_entries; i++) {
221 		if (!mp_irq_mpc_intsrc_cmp(&mp_irqs[i], m))
222 			return;
223 	}
224 
225 	assign_to_mp_irq(m, &mp_irqs[mp_irq_entries]);
226 	if (++mp_irq_entries == MAX_IRQ_SOURCES)
227 		panic("Max # of irq sources exceeded!!\n");
228 }
229 #else /* CONFIG_X86_IO_APIC */
230 static inline void __init MP_bus_info(struct mpc_bus *m) {}
231 static inline void __init MP_ioapic_info(struct mpc_ioapic *m) {}
232 static inline void __init MP_intsrc_info(struct mpc_intsrc *m) {}
233 #endif /* CONFIG_X86_IO_APIC */
234 
235 
236 static void __init MP_lintsrc_info(struct mpc_lintsrc *m)
237 {
238 	apic_printk(APIC_VERBOSE, "Lint: type %d, pol %d, trig %d, bus %02x,"
239 		" IRQ %02x, APIC ID %x, APIC LINT %02x\n",
240 		m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbusid,
241 		m->srcbusirq, m->destapic, m->destapiclint);
242 }
243 
244 /*
245  * Read/parse the MPC
246  */
247 
248 static int __init smp_check_mpc(struct mpc_table *mpc, char *oem, char *str)
249 {
250 
251 	if (memcmp(mpc->signature, MPC_SIGNATURE, 4)) {
252 		printk(KERN_ERR "MPTABLE: bad signature [%c%c%c%c]!\n",
253 		       mpc->signature[0], mpc->signature[1],
254 		       mpc->signature[2], mpc->signature[3]);
255 		return 0;
256 	}
257 	if (mpf_checksum((unsigned char *)mpc, mpc->length)) {
258 		printk(KERN_ERR "MPTABLE: checksum error!\n");
259 		return 0;
260 	}
261 	if (mpc->spec != 0x01 && mpc->spec != 0x04) {
262 		printk(KERN_ERR "MPTABLE: bad table version (%d)!!\n",
263 		       mpc->spec);
264 		return 0;
265 	}
266 	if (!mpc->lapic) {
267 		printk(KERN_ERR "MPTABLE: null local APIC address!\n");
268 		return 0;
269 	}
270 	memcpy(oem, mpc->oem, 8);
271 	oem[8] = 0;
272 	printk(KERN_INFO "MPTABLE: OEM ID: %s\n", oem);
273 
274 	memcpy(str, mpc->productid, 12);
275 	str[12] = 0;
276 
277 	printk(KERN_INFO "MPTABLE: Product ID: %s\n", str);
278 
279 	printk(KERN_INFO "MPTABLE: APIC at: 0x%X\n", mpc->lapic);
280 
281 	return 1;
282 }
283 
284 static void skip_entry(unsigned char **ptr, int *count, int size)
285 {
286 	*ptr += size;
287 	*count += size;
288 }
289 
290 static void __init smp_dump_mptable(struct mpc_table *mpc, unsigned char *mpt)
291 {
292 	printk(KERN_ERR "Your mptable is wrong, contact your HW vendor!\n"
293 		"type %x\n", *mpt);
294 	print_hex_dump(KERN_ERR, "  ", DUMP_PREFIX_ADDRESS, 16,
295 			1, mpc, mpc->length, 1);
296 }
297 
298 void __init default_smp_read_mpc_oem(struct mpc_table *mpc) { }
299 
300 static int __init smp_read_mpc(struct mpc_table *mpc, unsigned early)
301 {
302 	char str[16];
303 	char oem[10];
304 
305 	int count = sizeof(*mpc);
306 	unsigned char *mpt = ((unsigned char *)mpc) + count;
307 
308 	if (!smp_check_mpc(mpc, oem, str))
309 		return 0;
310 
311 #ifdef CONFIG_X86_32
312 	generic_mps_oem_check(mpc, oem, str);
313 #endif
314 	/* save the local APIC address, it might be non-default */
315 	if (!acpi_lapic)
316 		mp_lapic_addr = mpc->lapic;
317 
318 	if (early)
319 		return 1;
320 
321 	if (mpc->oemptr)
322 		x86_init.mpparse.smp_read_mpc_oem(mpc);
323 
324 	/*
325 	 *      Now process the configuration blocks.
326 	 */
327 	x86_init.mpparse.mpc_record(0);
328 
329 	while (count < mpc->length) {
330 		switch (*mpt) {
331 		case MP_PROCESSOR:
332 			/* ACPI may have already provided this data */
333 			if (!acpi_lapic)
334 				MP_processor_info((struct mpc_cpu *)mpt);
335 			skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
336 			break;
337 		case MP_BUS:
338 			MP_bus_info((struct mpc_bus *)mpt);
339 			skip_entry(&mpt, &count, sizeof(struct mpc_bus));
340 			break;
341 		case MP_IOAPIC:
342 			MP_ioapic_info((struct mpc_ioapic *)mpt);
343 			skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
344 			break;
345 		case MP_INTSRC:
346 			MP_intsrc_info((struct mpc_intsrc *)mpt);
347 			skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
348 			break;
349 		case MP_LINTSRC:
350 			MP_lintsrc_info((struct mpc_lintsrc *)mpt);
351 			skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
352 			break;
353 		default:
354 			/* wrong mptable */
355 			smp_dump_mptable(mpc, mpt);
356 			count = mpc->length;
357 			break;
358 		}
359 		x86_init.mpparse.mpc_record(1);
360 	}
361 
362 #ifdef CONFIG_X86_BIGSMP
363 	generic_bigsmp_probe();
364 #endif
365 
366 	if (apic->setup_apic_routing)
367 		apic->setup_apic_routing();
368 
369 	if (!num_processors)
370 		printk(KERN_ERR "MPTABLE: no processors registered!\n");
371 	return num_processors;
372 }
373 
374 #ifdef CONFIG_X86_IO_APIC
375 
376 static int __init ELCR_trigger(unsigned int irq)
377 {
378 	unsigned int port;
379 
380 	port = 0x4d0 + (irq >> 3);
381 	return (inb(port) >> (irq & 7)) & 1;
382 }
383 
384 static void __init construct_default_ioirq_mptable(int mpc_default_type)
385 {
386 	struct mpc_intsrc intsrc;
387 	int i;
388 	int ELCR_fallback = 0;
389 
390 	intsrc.type = MP_INTSRC;
391 	intsrc.irqflag = 0;	/* conforming */
392 	intsrc.srcbus = 0;
393 	intsrc.dstapic = mp_ioapics[0].apicid;
394 
395 	intsrc.irqtype = mp_INT;
396 
397 	/*
398 	 *  If true, we have an ISA/PCI system with no IRQ entries
399 	 *  in the MP table. To prevent the PCI interrupts from being set up
400 	 *  incorrectly, we try to use the ELCR. The sanity check to see if
401 	 *  there is good ELCR data is very simple - IRQ0, 1, 2 and 13 can
402 	 *  never be level sensitive, so we simply see if the ELCR agrees.
403 	 *  If it does, we assume it's valid.
404 	 */
405 	if (mpc_default_type == 5) {
406 		printk(KERN_INFO "ISA/PCI bus type with no IRQ information... "
407 		       "falling back to ELCR\n");
408 
409 		if (ELCR_trigger(0) || ELCR_trigger(1) || ELCR_trigger(2) ||
410 		    ELCR_trigger(13))
411 			printk(KERN_ERR "ELCR contains invalid data... "
412 			       "not using ELCR\n");
413 		else {
414 			printk(KERN_INFO
415 			       "Using ELCR to identify PCI interrupts\n");
416 			ELCR_fallback = 1;
417 		}
418 	}
419 
420 	for (i = 0; i < 16; i++) {
421 		switch (mpc_default_type) {
422 		case 2:
423 			if (i == 0 || i == 13)
424 				continue;	/* IRQ0 & IRQ13 not connected */
425 			/* fall through */
426 		default:
427 			if (i == 2)
428 				continue;	/* IRQ2 is never connected */
429 		}
430 
431 		if (ELCR_fallback) {
432 			/*
433 			 *  If the ELCR indicates a level-sensitive interrupt, we
434 			 *  copy that information over to the MP table in the
435 			 *  irqflag field (level sensitive, active high polarity).
436 			 */
437 			if (ELCR_trigger(i))
438 				intsrc.irqflag = 13;
439 			else
440 				intsrc.irqflag = 0;
441 		}
442 
443 		intsrc.srcbusirq = i;
444 		intsrc.dstirq = i ? i : 2;	/* IRQ0 to INTIN2 */
445 		MP_intsrc_info(&intsrc);
446 	}
447 
448 	intsrc.irqtype = mp_ExtINT;
449 	intsrc.srcbusirq = 0;
450 	intsrc.dstirq = 0;	/* 8259A to INTIN0 */
451 	MP_intsrc_info(&intsrc);
452 }
453 
454 
455 static void __init construct_ioapic_table(int mpc_default_type)
456 {
457 	struct mpc_ioapic ioapic;
458 	struct mpc_bus bus;
459 
460 	bus.type = MP_BUS;
461 	bus.busid = 0;
462 	switch (mpc_default_type) {
463 	default:
464 		printk(KERN_ERR "???\nUnknown standard configuration %d\n",
465 		       mpc_default_type);
466 		/* fall through */
467 	case 1:
468 	case 5:
469 		memcpy(bus.bustype, "ISA   ", 6);
470 		break;
471 	case 2:
472 	case 6:
473 	case 3:
474 		memcpy(bus.bustype, "EISA  ", 6);
475 		break;
476 	case 4:
477 	case 7:
478 		memcpy(bus.bustype, "MCA   ", 6);
479 	}
480 	MP_bus_info(&bus);
481 	if (mpc_default_type > 4) {
482 		bus.busid = 1;
483 		memcpy(bus.bustype, "PCI   ", 6);
484 		MP_bus_info(&bus);
485 	}
486 
487 	ioapic.type	= MP_IOAPIC;
488 	ioapic.apicid	= 2;
489 	ioapic.apicver	= mpc_default_type > 4 ? 0x10 : 0x01;
490 	ioapic.flags	= MPC_APIC_USABLE;
491 	ioapic.apicaddr	= IO_APIC_DEFAULT_PHYS_BASE;
492 	MP_ioapic_info(&ioapic);
493 
494 	/*
495 	 * We set up most of the low 16 IO-APIC pins according to MPS rules.
496 	 */
497 	construct_default_ioirq_mptable(mpc_default_type);
498 }
499 #else
500 static inline void __init construct_ioapic_table(int mpc_default_type) { }
501 #endif
502 
503 static inline void __init construct_default_ISA_mptable(int mpc_default_type)
504 {
505 	struct mpc_cpu processor;
506 	struct mpc_lintsrc lintsrc;
507 	int linttypes[2] = { mp_ExtINT, mp_NMI };
508 	int i;
509 
510 	/*
511 	 * local APIC has default address
512 	 */
513 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
514 
515 	/*
516 	 * 2 CPUs, numbered 0 & 1.
517 	 */
518 	processor.type = MP_PROCESSOR;
519 	/* Either an integrated APIC or a discrete 82489DX. */
520 	processor.apicver = mpc_default_type > 4 ? 0x10 : 0x01;
521 	processor.cpuflag = CPU_ENABLED;
522 	processor.cpufeature = (boot_cpu_data.x86 << 8) |
523 	    (boot_cpu_data.x86_model << 4) | boot_cpu_data.x86_mask;
524 	processor.featureflag = boot_cpu_data.x86_capability[0];
525 	processor.reserved[0] = 0;
526 	processor.reserved[1] = 0;
527 	for (i = 0; i < 2; i++) {
528 		processor.apicid = i;
529 		MP_processor_info(&processor);
530 	}
531 
532 	construct_ioapic_table(mpc_default_type);
533 
534 	lintsrc.type = MP_LINTSRC;
535 	lintsrc.irqflag = 0;		/* conforming */
536 	lintsrc.srcbusid = 0;
537 	lintsrc.srcbusirq = 0;
538 	lintsrc.destapic = MP_APIC_ALL;
539 	for (i = 0; i < 2; i++) {
540 		lintsrc.irqtype = linttypes[i];
541 		lintsrc.destapiclint = i;
542 		MP_lintsrc_info(&lintsrc);
543 	}
544 }
545 
546 static struct mpf_intel *mpf_found;
547 
548 static unsigned long __init get_mpc_size(unsigned long physptr)
549 {
550 	struct mpc_table *mpc;
551 	unsigned long size;
552 
553 	mpc = early_ioremap(physptr, PAGE_SIZE);
554 	size = mpc->length;
555 	early_iounmap(mpc, PAGE_SIZE);
556 	apic_printk(APIC_VERBOSE, "  mpc: %lx-%lx\n", physptr, physptr + size);
557 
558 	return size;
559 }
560 
561 static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
562 {
563 	struct mpc_table *mpc;
564 	unsigned long size;
565 
566 	size = get_mpc_size(mpf->physptr);
567 	mpc = early_ioremap(mpf->physptr, size);
568 	/*
569 	 * Read the physical hardware table.  Anything here will
570 	 * override the defaults.
571 	 */
572 	if (!smp_read_mpc(mpc, early)) {
573 #ifdef CONFIG_X86_LOCAL_APIC
574 		smp_found_config = 0;
575 #endif
576 		printk(KERN_ERR "BIOS bug, MP table errors detected!...\n"
577 			"... disabling SMP support. (tell your hw vendor)\n");
578 		early_iounmap(mpc, size);
579 		return -1;
580 	}
581 	early_iounmap(mpc, size);
582 
583 	if (early)
584 		return -1;
585 
586 #ifdef CONFIG_X86_IO_APIC
587 	/*
588 	 * If there are no explicit MP IRQ entries, then we are
589 	 * broken.  We set up most of the low 16 IO-APIC pins to
590 	 * ISA defaults and hope it will work.
591 	 */
592 	if (!mp_irq_entries) {
593 		struct mpc_bus bus;
594 
595 		printk(KERN_ERR "BIOS bug, no explicit IRQ entries, "
596 		       "using default mptable. (tell your hw vendor)\n");
597 
598 		bus.type = MP_BUS;
599 		bus.busid = 0;
600 		memcpy(bus.bustype, "ISA   ", 6);
601 		MP_bus_info(&bus);
602 
603 		construct_default_ioirq_mptable(0);
604 	}
605 #endif
606 
607 	return 0;
608 }
609 
610 /*
611  * Scan the memory blocks for an SMP configuration block.
612  */
613 void __init default_get_smp_config(unsigned int early)
614 {
615 	struct mpf_intel *mpf = mpf_found;
616 
617 	if (!mpf)
618 		return;
619 
620 	if (acpi_lapic && early)
621 		return;
622 
623 	/*
624 	 * MPS doesn't support hyperthreading, aka only have
625 	 * thread 0 apic id in MPS table
626 	 */
627 	if (acpi_lapic && acpi_ioapic)
628 		return;
629 
630 	printk(KERN_INFO "Intel MultiProcessor Specification v1.%d\n",
631 	       mpf->specification);
632 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)
633 	if (mpf->feature2 & (1 << 7)) {
634 		printk(KERN_INFO "    IMCR and PIC compatibility mode.\n");
635 		pic_mode = 1;
636 	} else {
637 		printk(KERN_INFO "    Virtual Wire compatibility mode.\n");
638 		pic_mode = 0;
639 	}
640 #endif
641 	/*
642 	 * Now see if we need to read further.
643 	 */
644 	if (mpf->feature1 != 0) {
645 		if (early) {
646 			/*
647 			 * local APIC has default address
648 			 */
649 			mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
650 			return;
651 		}
652 
653 		printk(KERN_INFO "Default MP configuration #%d\n",
654 		       mpf->feature1);
655 		construct_default_ISA_mptable(mpf->feature1);
656 
657 	} else if (mpf->physptr) {
658 		if (check_physptr(mpf, early))
659 			return;
660 	} else
661 		BUG();
662 
663 	if (!early)
664 		printk(KERN_INFO "Processors: %d\n", num_processors);
665 	/*
666 	 * Only use the first configuration found.
667 	 */
668 }
669 
670 static void __init smp_reserve_bootmem(struct mpf_intel *mpf)
671 {
672 	unsigned long size = get_mpc_size(mpf->physptr);
673 #ifdef CONFIG_X86_32
674 	/*
675 	 * We cannot access to MPC table to compute table size yet,
676 	 * as only few megabytes from the bottom is mapped now.
677 	 * PC-9800's MPC table places on the very last of physical
678 	 * memory; so that simply reserving PAGE_SIZE from mpf->physptr
679 	 * yields BUG() in reserve_bootmem.
680 	 * also need to make sure physptr is below than max_low_pfn
681 	 * we don't need reserve the area above max_low_pfn
682 	 */
683 	unsigned long end = max_low_pfn * PAGE_SIZE;
684 
685 	if (mpf->physptr < end) {
686 		if (mpf->physptr + size > end)
687 			size = end - mpf->physptr;
688 		reserve_bootmem_generic(mpf->physptr, size, BOOTMEM_DEFAULT);
689 	}
690 #else
691 	reserve_bootmem_generic(mpf->physptr, size, BOOTMEM_DEFAULT);
692 #endif
693 }
694 
695 static int __init smp_scan_config(unsigned long base, unsigned long length,
696 				  unsigned reserve)
697 {
698 	unsigned int *bp = phys_to_virt(base);
699 	struct mpf_intel *mpf;
700 
701 	apic_printk(APIC_VERBOSE, "Scan SMP from %p for %ld bytes.\n",
702 			bp, length);
703 	BUILD_BUG_ON(sizeof(*mpf) != 16);
704 
705 	while (length > 0) {
706 		mpf = (struct mpf_intel *)bp;
707 		if ((*bp == SMP_MAGIC_IDENT) &&
708 		    (mpf->length == 1) &&
709 		    !mpf_checksum((unsigned char *)bp, 16) &&
710 		    ((mpf->specification == 1)
711 		     || (mpf->specification == 4))) {
712 #ifdef CONFIG_X86_LOCAL_APIC
713 			smp_found_config = 1;
714 #endif
715 			mpf_found = mpf;
716 
717 			printk(KERN_INFO "found SMP MP-table at [%p] %llx\n",
718 			       mpf, (u64)virt_to_phys(mpf));
719 
720 			if (!reserve)
721 				return 1;
722 			reserve_bootmem_generic(virt_to_phys(mpf), sizeof(*mpf),
723 						BOOTMEM_DEFAULT);
724 			if (mpf->physptr)
725 				smp_reserve_bootmem(mpf);
726 
727 			return 1;
728 		}
729 		bp += 4;
730 		length -= 16;
731 	}
732 	return 0;
733 }
734 
735 void __init default_find_smp_config(unsigned int reserve)
736 {
737 	unsigned int address;
738 
739 	/*
740 	 * FIXME: Linux assumes you have 640K of base ram..
741 	 * this continues the error...
742 	 *
743 	 * 1) Scan the bottom 1K for a signature
744 	 * 2) Scan the top 1K of base RAM
745 	 * 3) Scan the 64K of bios
746 	 */
747 	if (smp_scan_config(0x0, 0x400, reserve) ||
748 	    smp_scan_config(639 * 0x400, 0x400, reserve) ||
749 	    smp_scan_config(0xF0000, 0x10000, reserve))
750 		return;
751 	/*
752 	 * If it is an SMP machine we should know now, unless the
753 	 * configuration is in an EISA/MCA bus machine with an
754 	 * extended bios data area.
755 	 *
756 	 * there is a real-mode segmented pointer pointing to the
757 	 * 4K EBDA area at 0x40E, calculate and scan it here.
758 	 *
759 	 * NOTE! There are Linux loaders that will corrupt the EBDA
760 	 * area, and as such this kind of SMP config may be less
761 	 * trustworthy, simply because the SMP table may have been
762 	 * stomped on during early boot. These loaders are buggy and
763 	 * should be fixed.
764 	 *
765 	 * MP1.4 SPEC states to only scan first 1K of 4K EBDA.
766 	 */
767 
768 	address = get_bios_ebda();
769 	if (address)
770 		smp_scan_config(address, 0x400, reserve);
771 }
772 
773 #ifdef CONFIG_X86_IO_APIC
774 static u8 __initdata irq_used[MAX_IRQ_SOURCES];
775 
776 static int  __init get_MP_intsrc_index(struct mpc_intsrc *m)
777 {
778 	int i;
779 
780 	if (m->irqtype != mp_INT)
781 		return 0;
782 
783 	if (m->irqflag != 0x0f)
784 		return 0;
785 
786 	/* not legacy */
787 
788 	for (i = 0; i < mp_irq_entries; i++) {
789 		if (mp_irqs[i].irqtype != mp_INT)
790 			continue;
791 
792 		if (mp_irqs[i].irqflag != 0x0f)
793 			continue;
794 
795 		if (mp_irqs[i].srcbus != m->srcbus)
796 			continue;
797 		if (mp_irqs[i].srcbusirq != m->srcbusirq)
798 			continue;
799 		if (irq_used[i]) {
800 			/* already claimed */
801 			return -2;
802 		}
803 		irq_used[i] = 1;
804 		return i;
805 	}
806 
807 	/* not found */
808 	return -1;
809 }
810 
811 #define SPARE_SLOT_NUM 20
812 
813 static struct mpc_intsrc __initdata *m_spare[SPARE_SLOT_NUM];
814 
815 static void __init check_irq_src(struct mpc_intsrc *m, int *nr_m_spare)
816 {
817 	int i;
818 
819 	apic_printk(APIC_VERBOSE, "OLD ");
820 	print_MP_intsrc_info(m);
821 
822 	i = get_MP_intsrc_index(m);
823 	if (i > 0) {
824 		assign_to_mpc_intsrc(&mp_irqs[i], m);
825 		apic_printk(APIC_VERBOSE, "NEW ");
826 		print_mp_irq_info(&mp_irqs[i]);
827 		return;
828 	}
829 	if (!i) {
830 		/* legacy, do nothing */
831 		return;
832 	}
833 	if (*nr_m_spare < SPARE_SLOT_NUM) {
834 		/*
835 		 * not found (-1), or duplicated (-2) are invalid entries,
836 		 * we need to use the slot later
837 		 */
838 		m_spare[*nr_m_spare] = m;
839 		*nr_m_spare += 1;
840 	}
841 }
842 #else /* CONFIG_X86_IO_APIC */
843 static
844 inline void __init check_irq_src(struct mpc_intsrc *m, int *nr_m_spare) {}
845 #endif /* CONFIG_X86_IO_APIC */
846 
847 static int
848 check_slot(unsigned long mpc_new_phys, unsigned long mpc_new_length, int count)
849 {
850 	int ret = 0;
851 
852 	if (!mpc_new_phys || count <= mpc_new_length) {
853 		WARN(1, "update_mptable: No spare slots (length: %x)\n", count);
854 		return -1;
855 	}
856 
857 	return ret;
858 }
859 
860 static int  __init replace_intsrc_all(struct mpc_table *mpc,
861 					unsigned long mpc_new_phys,
862 					unsigned long mpc_new_length)
863 {
864 #ifdef CONFIG_X86_IO_APIC
865 	int i;
866 #endif
867 	int count = sizeof(*mpc);
868 	int nr_m_spare = 0;
869 	unsigned char *mpt = ((unsigned char *)mpc) + count;
870 
871 	printk(KERN_INFO "mpc_length %x\n", mpc->length);
872 	while (count < mpc->length) {
873 		switch (*mpt) {
874 		case MP_PROCESSOR:
875 			skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
876 			break;
877 		case MP_BUS:
878 			skip_entry(&mpt, &count, sizeof(struct mpc_bus));
879 			break;
880 		case MP_IOAPIC:
881 			skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
882 			break;
883 		case MP_INTSRC:
884 			check_irq_src((struct mpc_intsrc *)mpt, &nr_m_spare);
885 			skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
886 			break;
887 		case MP_LINTSRC:
888 			skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
889 			break;
890 		default:
891 			/* wrong mptable */
892 			smp_dump_mptable(mpc, mpt);
893 			goto out;
894 		}
895 	}
896 
897 #ifdef CONFIG_X86_IO_APIC
898 	for (i = 0; i < mp_irq_entries; i++) {
899 		if (irq_used[i])
900 			continue;
901 
902 		if (mp_irqs[i].irqtype != mp_INT)
903 			continue;
904 
905 		if (mp_irqs[i].irqflag != 0x0f)
906 			continue;
907 
908 		if (nr_m_spare > 0) {
909 			apic_printk(APIC_VERBOSE, "*NEW* found\n");
910 			nr_m_spare--;
911 			assign_to_mpc_intsrc(&mp_irqs[i], m_spare[nr_m_spare]);
912 			m_spare[nr_m_spare] = NULL;
913 		} else {
914 			struct mpc_intsrc *m = (struct mpc_intsrc *)mpt;
915 			count += sizeof(struct mpc_intsrc);
916 			if (check_slot(mpc_new_phys, mpc_new_length, count) < 0)
917 				goto out;
918 			assign_to_mpc_intsrc(&mp_irqs[i], m);
919 			mpc->length = count;
920 			mpt += sizeof(struct mpc_intsrc);
921 		}
922 		print_mp_irq_info(&mp_irqs[i]);
923 	}
924 #endif
925 out:
926 	/* update checksum */
927 	mpc->checksum = 0;
928 	mpc->checksum -= mpf_checksum((unsigned char *)mpc, mpc->length);
929 
930 	return 0;
931 }
932 
933 int enable_update_mptable;
934 
935 static int __init update_mptable_setup(char *str)
936 {
937 	enable_update_mptable = 1;
938 #ifdef CONFIG_PCI
939 	pci_routeirq = 1;
940 #endif
941 	return 0;
942 }
943 early_param("update_mptable", update_mptable_setup);
944 
945 static unsigned long __initdata mpc_new_phys;
946 static unsigned long mpc_new_length __initdata = 4096;
947 
948 /* alloc_mptable or alloc_mptable=4k */
949 static int __initdata alloc_mptable;
950 static int __init parse_alloc_mptable_opt(char *p)
951 {
952 	enable_update_mptable = 1;
953 #ifdef CONFIG_PCI
954 	pci_routeirq = 1;
955 #endif
956 	alloc_mptable = 1;
957 	if (!p)
958 		return 0;
959 	mpc_new_length = memparse(p, &p);
960 	return 0;
961 }
962 early_param("alloc_mptable", parse_alloc_mptable_opt);
963 
964 void __init early_reserve_e820_mpc_new(void)
965 {
966 	if (enable_update_mptable && alloc_mptable) {
967 		u64 startt = 0;
968 #ifdef CONFIG_X86_TRAMPOLINE
969 		startt = TRAMPOLINE_BASE;
970 #endif
971 		mpc_new_phys = early_reserve_e820(startt, mpc_new_length, 4);
972 	}
973 }
974 
975 static int __init update_mp_table(void)
976 {
977 	char str[16];
978 	char oem[10];
979 	struct mpf_intel *mpf;
980 	struct mpc_table *mpc, *mpc_new;
981 
982 	if (!enable_update_mptable)
983 		return 0;
984 
985 	mpf = mpf_found;
986 	if (!mpf)
987 		return 0;
988 
989 	/*
990 	 * Now see if we need to go further.
991 	 */
992 	if (mpf->feature1 != 0)
993 		return 0;
994 
995 	if (!mpf->physptr)
996 		return 0;
997 
998 	mpc = phys_to_virt(mpf->physptr);
999 
1000 	if (!smp_check_mpc(mpc, oem, str))
1001 		return 0;
1002 
1003 	printk(KERN_INFO "mpf: %llx\n", (u64)virt_to_phys(mpf));
1004 	printk(KERN_INFO "physptr: %x\n", mpf->physptr);
1005 
1006 	if (mpc_new_phys && mpc->length > mpc_new_length) {
1007 		mpc_new_phys = 0;
1008 		printk(KERN_INFO "mpc_new_length is %ld, please use alloc_mptable=8k\n",
1009 			 mpc_new_length);
1010 	}
1011 
1012 	if (!mpc_new_phys) {
1013 		unsigned char old, new;
1014 		/* check if we can change the postion */
1015 		mpc->checksum = 0;
1016 		old = mpf_checksum((unsigned char *)mpc, mpc->length);
1017 		mpc->checksum = 0xff;
1018 		new = mpf_checksum((unsigned char *)mpc, mpc->length);
1019 		if (old == new) {
1020 			printk(KERN_INFO "mpc is readonly, please try alloc_mptable instead\n");
1021 			return 0;
1022 		}
1023 		printk(KERN_INFO "use in-positon replacing\n");
1024 	} else {
1025 		mpf->physptr = mpc_new_phys;
1026 		mpc_new = phys_to_virt(mpc_new_phys);
1027 		memcpy(mpc_new, mpc, mpc->length);
1028 		mpc = mpc_new;
1029 		/* check if we can modify that */
1030 		if (mpc_new_phys - mpf->physptr) {
1031 			struct mpf_intel *mpf_new;
1032 			/* steal 16 bytes from [0, 1k) */
1033 			printk(KERN_INFO "mpf new: %x\n", 0x400 - 16);
1034 			mpf_new = phys_to_virt(0x400 - 16);
1035 			memcpy(mpf_new, mpf, 16);
1036 			mpf = mpf_new;
1037 			mpf->physptr = mpc_new_phys;
1038 		}
1039 		mpf->checksum = 0;
1040 		mpf->checksum -= mpf_checksum((unsigned char *)mpf, 16);
1041 		printk(KERN_INFO "physptr new: %x\n", mpf->physptr);
1042 	}
1043 
1044 	/*
1045 	 * only replace the one with mp_INT and
1046 	 *	 MP_IRQ_TRIGGER_LEVEL|MP_IRQ_POLARITY_LOW,
1047 	 * already in mp_irqs , stored by ... and mp_config_acpi_gsi,
1048 	 * may need pci=routeirq for all coverage
1049 	 */
1050 	replace_intsrc_all(mpc, mpc_new_phys, mpc_new_length);
1051 
1052 	return 0;
1053 }
1054 
1055 late_initcall(update_mp_table);
1056