xref: /linux/arch/x86/kernel/mpparse.c (revision 6084a6e23c971ef703229ee1aec68d01688578d6)
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/memblock.h>
15 #include <linux/kernel_stat.h>
16 #include <linux/mc146818rtc.h>
17 #include <linux/bitops.h>
18 #include <linux/acpi.h>
19 #include <linux/module.h>
20 #include <linux/smp.h>
21 #include <linux/pci.h>
22 
23 #include <asm/mtrr.h>
24 #include <asm/mpspec.h>
25 #include <asm/pgalloc.h>
26 #include <asm/io_apic.h>
27 #include <asm/proto.h>
28 #include <asm/bios_ebda.h>
29 #include <asm/e820.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 	pr_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 		pr_warn("MP table busid value (%d) for bustype %s is too large, max. supported is %d\n",
91 			m->busid, str, MAX_MP_BUSSES - 1);
92 		return;
93 	}
94 #endif
95 
96 	set_bit(m->busid, mp_bus_not_pci);
97 	if (strncmp(str, BUSTYPE_ISA, sizeof(BUSTYPE_ISA) - 1) == 0) {
98 #ifdef CONFIG_EISA
99 		mp_bus_id_to_type[m->busid] = MP_BUS_ISA;
100 #endif
101 	} else if (strncmp(str, BUSTYPE_PCI, sizeof(BUSTYPE_PCI) - 1) == 0) {
102 		if (x86_init.mpparse.mpc_oem_pci_bus)
103 			x86_init.mpparse.mpc_oem_pci_bus(m);
104 
105 		clear_bit(m->busid, mp_bus_not_pci);
106 #ifdef CONFIG_EISA
107 		mp_bus_id_to_type[m->busid] = MP_BUS_PCI;
108 	} else if (strncmp(str, BUSTYPE_EISA, sizeof(BUSTYPE_EISA) - 1) == 0) {
109 		mp_bus_id_to_type[m->busid] = MP_BUS_EISA;
110 #endif
111 	} else
112 		pr_warn("Unknown bustype %s - ignoring\n", str);
113 }
114 
115 static void __init MP_ioapic_info(struct mpc_ioapic *m)
116 {
117 	if (m->flags & MPC_APIC_USABLE)
118 		mp_register_ioapic(m->apicid, m->apicaddr, gsi_top);
119 }
120 
121 static void __init print_mp_irq_info(struct mpc_intsrc *mp_irq)
122 {
123 	apic_printk(APIC_VERBOSE,
124 		"Int: type %d, pol %d, trig %d, bus %02x, IRQ %02x, APIC ID %x, APIC INT %02x\n",
125 		mp_irq->irqtype, mp_irq->irqflag & 3,
126 		(mp_irq->irqflag >> 2) & 3, mp_irq->srcbus,
127 		mp_irq->srcbusirq, mp_irq->dstapic, mp_irq->dstirq);
128 }
129 
130 #else /* CONFIG_X86_IO_APIC */
131 static inline void __init MP_bus_info(struct mpc_bus *m) {}
132 static inline void __init MP_ioapic_info(struct mpc_ioapic *m) {}
133 #endif /* CONFIG_X86_IO_APIC */
134 
135 static void __init MP_lintsrc_info(struct mpc_lintsrc *m)
136 {
137 	apic_printk(APIC_VERBOSE,
138 		"Lint: type %d, pol %d, trig %d, bus %02x, IRQ %02x, APIC ID %x, APIC LINT %02x\n",
139 		m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbusid,
140 		m->srcbusirq, m->destapic, m->destapiclint);
141 }
142 
143 /*
144  * Read/parse the MPC
145  */
146 static int __init smp_check_mpc(struct mpc_table *mpc, char *oem, char *str)
147 {
148 
149 	if (memcmp(mpc->signature, MPC_SIGNATURE, 4)) {
150 		pr_err("MPTABLE: bad signature [%c%c%c%c]!\n",
151 		       mpc->signature[0], mpc->signature[1],
152 		       mpc->signature[2], mpc->signature[3]);
153 		return 0;
154 	}
155 	if (mpf_checksum((unsigned char *)mpc, mpc->length)) {
156 		pr_err("MPTABLE: checksum error!\n");
157 		return 0;
158 	}
159 	if (mpc->spec != 0x01 && mpc->spec != 0x04) {
160 		pr_err("MPTABLE: bad table version (%d)!!\n", mpc->spec);
161 		return 0;
162 	}
163 	if (!mpc->lapic) {
164 		pr_err("MPTABLE: null local APIC address!\n");
165 		return 0;
166 	}
167 	memcpy(oem, mpc->oem, 8);
168 	oem[8] = 0;
169 	pr_info("MPTABLE: OEM ID: %s\n", oem);
170 
171 	memcpy(str, mpc->productid, 12);
172 	str[12] = 0;
173 
174 	pr_info("MPTABLE: Product ID: %s\n", str);
175 
176 	pr_info("MPTABLE: APIC at: 0x%X\n", mpc->lapic);
177 
178 	return 1;
179 }
180 
181 static void skip_entry(unsigned char **ptr, int *count, int size)
182 {
183 	*ptr += size;
184 	*count += size;
185 }
186 
187 static void __init smp_dump_mptable(struct mpc_table *mpc, unsigned char *mpt)
188 {
189 	pr_err("Your mptable is wrong, contact your HW vendor!\n");
190 	pr_cont("type %x\n", *mpt);
191 	print_hex_dump(KERN_ERR, "  ", DUMP_PREFIX_ADDRESS, 16,
192 			1, mpc, mpc->length, 1);
193 }
194 
195 void __init default_smp_read_mpc_oem(struct mpc_table *mpc) { }
196 
197 static int __init smp_read_mpc(struct mpc_table *mpc, unsigned early)
198 {
199 	char str[16];
200 	char oem[10];
201 
202 	int count = sizeof(*mpc);
203 	unsigned char *mpt = ((unsigned char *)mpc) + count;
204 
205 	if (!smp_check_mpc(mpc, oem, str))
206 		return 0;
207 
208 #ifdef CONFIG_X86_32
209 	generic_mps_oem_check(mpc, oem, str);
210 #endif
211 	/* Initialize the lapic mapping */
212 	if (!acpi_lapic)
213 		register_lapic_address(mpc->lapic);
214 
215 	if (early)
216 		return 1;
217 
218 	if (mpc->oemptr)
219 		x86_init.mpparse.smp_read_mpc_oem(mpc);
220 
221 	/*
222 	 *      Now process the configuration blocks.
223 	 */
224 	x86_init.mpparse.mpc_record(0);
225 
226 	while (count < mpc->length) {
227 		switch (*mpt) {
228 		case MP_PROCESSOR:
229 			/* ACPI may have already provided this data */
230 			if (!acpi_lapic)
231 				MP_processor_info((struct mpc_cpu *)mpt);
232 			skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
233 			break;
234 		case MP_BUS:
235 			MP_bus_info((struct mpc_bus *)mpt);
236 			skip_entry(&mpt, &count, sizeof(struct mpc_bus));
237 			break;
238 		case MP_IOAPIC:
239 			MP_ioapic_info((struct mpc_ioapic *)mpt);
240 			skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
241 			break;
242 		case MP_INTSRC:
243 			mp_save_irq((struct mpc_intsrc *)mpt);
244 			skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
245 			break;
246 		case MP_LINTSRC:
247 			MP_lintsrc_info((struct mpc_lintsrc *)mpt);
248 			skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
249 			break;
250 		default:
251 			/* wrong mptable */
252 			smp_dump_mptable(mpc, mpt);
253 			count = mpc->length;
254 			break;
255 		}
256 		x86_init.mpparse.mpc_record(1);
257 	}
258 
259 	if (!num_processors)
260 		pr_err("MPTABLE: no processors registered!\n");
261 	return num_processors;
262 }
263 
264 #ifdef CONFIG_X86_IO_APIC
265 
266 static int __init ELCR_trigger(unsigned int irq)
267 {
268 	unsigned int port;
269 
270 	port = 0x4d0 + (irq >> 3);
271 	return (inb(port) >> (irq & 7)) & 1;
272 }
273 
274 static void __init construct_default_ioirq_mptable(int mpc_default_type)
275 {
276 	struct mpc_intsrc intsrc;
277 	int i;
278 	int ELCR_fallback = 0;
279 
280 	intsrc.type = MP_INTSRC;
281 	intsrc.irqflag = 0;	/* conforming */
282 	intsrc.srcbus = 0;
283 	intsrc.dstapic = mpc_ioapic_id(0);
284 
285 	intsrc.irqtype = mp_INT;
286 
287 	/*
288 	 *  If true, we have an ISA/PCI system with no IRQ entries
289 	 *  in the MP table. To prevent the PCI interrupts from being set up
290 	 *  incorrectly, we try to use the ELCR. The sanity check to see if
291 	 *  there is good ELCR data is very simple - IRQ0, 1, 2 and 13 can
292 	 *  never be level sensitive, so we simply see if the ELCR agrees.
293 	 *  If it does, we assume it's valid.
294 	 */
295 	if (mpc_default_type == 5) {
296 		pr_info("ISA/PCI bus type with no IRQ information... falling back to ELCR\n");
297 
298 		if (ELCR_trigger(0) || ELCR_trigger(1) || ELCR_trigger(2) ||
299 		    ELCR_trigger(13))
300 			pr_err("ELCR contains invalid data... not using ELCR\n");
301 		else {
302 			pr_info("Using ELCR to identify PCI interrupts\n");
303 			ELCR_fallback = 1;
304 		}
305 	}
306 
307 	for (i = 0; i < 16; i++) {
308 		switch (mpc_default_type) {
309 		case 2:
310 			if (i == 0 || i == 13)
311 				continue;	/* IRQ0 & IRQ13 not connected */
312 			/* fall through */
313 		default:
314 			if (i == 2)
315 				continue;	/* IRQ2 is never connected */
316 		}
317 
318 		if (ELCR_fallback) {
319 			/*
320 			 *  If the ELCR indicates a level-sensitive interrupt, we
321 			 *  copy that information over to the MP table in the
322 			 *  irqflag field (level sensitive, active high polarity).
323 			 */
324 			if (ELCR_trigger(i))
325 				intsrc.irqflag = 13;
326 			else
327 				intsrc.irqflag = 0;
328 		}
329 
330 		intsrc.srcbusirq = i;
331 		intsrc.dstirq = i ? i : 2;	/* IRQ0 to INTIN2 */
332 		mp_save_irq(&intsrc);
333 	}
334 
335 	intsrc.irqtype = mp_ExtINT;
336 	intsrc.srcbusirq = 0;
337 	intsrc.dstirq = 0;	/* 8259A to INTIN0 */
338 	mp_save_irq(&intsrc);
339 }
340 
341 
342 static void __init construct_ioapic_table(int mpc_default_type)
343 {
344 	struct mpc_ioapic ioapic;
345 	struct mpc_bus bus;
346 
347 	bus.type = MP_BUS;
348 	bus.busid = 0;
349 	switch (mpc_default_type) {
350 	default:
351 		pr_err("???\nUnknown standard configuration %d\n",
352 		       mpc_default_type);
353 		/* fall through */
354 	case 1:
355 	case 5:
356 		memcpy(bus.bustype, "ISA   ", 6);
357 		break;
358 	case 2:
359 	case 6:
360 	case 3:
361 		memcpy(bus.bustype, "EISA  ", 6);
362 		break;
363 	}
364 	MP_bus_info(&bus);
365 	if (mpc_default_type > 4) {
366 		bus.busid = 1;
367 		memcpy(bus.bustype, "PCI   ", 6);
368 		MP_bus_info(&bus);
369 	}
370 
371 	ioapic.type	= MP_IOAPIC;
372 	ioapic.apicid	= 2;
373 	ioapic.apicver	= mpc_default_type > 4 ? 0x10 : 0x01;
374 	ioapic.flags	= MPC_APIC_USABLE;
375 	ioapic.apicaddr	= IO_APIC_DEFAULT_PHYS_BASE;
376 	MP_ioapic_info(&ioapic);
377 
378 	/*
379 	 * We set up most of the low 16 IO-APIC pins according to MPS rules.
380 	 */
381 	construct_default_ioirq_mptable(mpc_default_type);
382 }
383 #else
384 static inline void __init construct_ioapic_table(int mpc_default_type) { }
385 #endif
386 
387 static inline void __init construct_default_ISA_mptable(int mpc_default_type)
388 {
389 	struct mpc_cpu processor;
390 	struct mpc_lintsrc lintsrc;
391 	int linttypes[2] = { mp_ExtINT, mp_NMI };
392 	int i;
393 
394 	/*
395 	 * local APIC has default address
396 	 */
397 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
398 
399 	/*
400 	 * 2 CPUs, numbered 0 & 1.
401 	 */
402 	processor.type = MP_PROCESSOR;
403 	/* Either an integrated APIC or a discrete 82489DX. */
404 	processor.apicver = mpc_default_type > 4 ? 0x10 : 0x01;
405 	processor.cpuflag = CPU_ENABLED;
406 	processor.cpufeature = (boot_cpu_data.x86 << 8) |
407 	    (boot_cpu_data.x86_model << 4) | boot_cpu_data.x86_mask;
408 	processor.featureflag = boot_cpu_data.x86_capability[0];
409 	processor.reserved[0] = 0;
410 	processor.reserved[1] = 0;
411 	for (i = 0; i < 2; i++) {
412 		processor.apicid = i;
413 		MP_processor_info(&processor);
414 	}
415 
416 	construct_ioapic_table(mpc_default_type);
417 
418 	lintsrc.type = MP_LINTSRC;
419 	lintsrc.irqflag = 0;		/* conforming */
420 	lintsrc.srcbusid = 0;
421 	lintsrc.srcbusirq = 0;
422 	lintsrc.destapic = MP_APIC_ALL;
423 	for (i = 0; i < 2; i++) {
424 		lintsrc.irqtype = linttypes[i];
425 		lintsrc.destapiclint = i;
426 		MP_lintsrc_info(&lintsrc);
427 	}
428 }
429 
430 static struct mpf_intel *mpf_found;
431 
432 static unsigned long __init get_mpc_size(unsigned long physptr)
433 {
434 	struct mpc_table *mpc;
435 	unsigned long size;
436 
437 	mpc = early_ioremap(physptr, PAGE_SIZE);
438 	size = mpc->length;
439 	early_iounmap(mpc, PAGE_SIZE);
440 	apic_printk(APIC_VERBOSE, "  mpc: %lx-%lx\n", physptr, physptr + size);
441 
442 	return size;
443 }
444 
445 static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
446 {
447 	struct mpc_table *mpc;
448 	unsigned long size;
449 
450 	size = get_mpc_size(mpf->physptr);
451 	mpc = early_ioremap(mpf->physptr, size);
452 	/*
453 	 * Read the physical hardware table.  Anything here will
454 	 * override the defaults.
455 	 */
456 	if (!smp_read_mpc(mpc, early)) {
457 #ifdef CONFIG_X86_LOCAL_APIC
458 		smp_found_config = 0;
459 #endif
460 		pr_err("BIOS bug, MP table errors detected!...\n");
461 		pr_cont("... disabling SMP support. (tell your hw vendor)\n");
462 		early_iounmap(mpc, size);
463 		return -1;
464 	}
465 	early_iounmap(mpc, size);
466 
467 	if (early)
468 		return -1;
469 
470 #ifdef CONFIG_X86_IO_APIC
471 	/*
472 	 * If there are no explicit MP IRQ entries, then we are
473 	 * broken.  We set up most of the low 16 IO-APIC pins to
474 	 * ISA defaults and hope it will work.
475 	 */
476 	if (!mp_irq_entries) {
477 		struct mpc_bus bus;
478 
479 		pr_err("BIOS bug, no explicit IRQ entries, using default mptable. (tell your hw vendor)\n");
480 
481 		bus.type = MP_BUS;
482 		bus.busid = 0;
483 		memcpy(bus.bustype, "ISA   ", 6);
484 		MP_bus_info(&bus);
485 
486 		construct_default_ioirq_mptable(0);
487 	}
488 #endif
489 
490 	return 0;
491 }
492 
493 /*
494  * Scan the memory blocks for an SMP configuration block.
495  */
496 void __init default_get_smp_config(unsigned int early)
497 {
498 	struct mpf_intel *mpf = mpf_found;
499 
500 	if (!mpf)
501 		return;
502 
503 	if (acpi_lapic && early)
504 		return;
505 
506 	/*
507 	 * MPS doesn't support hyperthreading, aka only have
508 	 * thread 0 apic id in MPS table
509 	 */
510 	if (acpi_lapic && acpi_ioapic)
511 		return;
512 
513 	pr_info("Intel MultiProcessor Specification v1.%d\n",
514 		mpf->specification);
515 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)
516 	if (mpf->feature2 & (1 << 7)) {
517 		pr_info("    IMCR and PIC compatibility mode.\n");
518 		pic_mode = 1;
519 	} else {
520 		pr_info("    Virtual Wire compatibility mode.\n");
521 		pic_mode = 0;
522 	}
523 #endif
524 	/*
525 	 * Now see if we need to read further.
526 	 */
527 	if (mpf->feature1 != 0) {
528 		if (early) {
529 			/*
530 			 * local APIC has default address
531 			 */
532 			mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
533 			return;
534 		}
535 
536 		pr_info("Default MP configuration #%d\n", mpf->feature1);
537 		construct_default_ISA_mptable(mpf->feature1);
538 
539 	} else if (mpf->physptr) {
540 		if (check_physptr(mpf, early))
541 			return;
542 	} else
543 		BUG();
544 
545 	if (!early)
546 		pr_info("Processors: %d\n", num_processors);
547 	/*
548 	 * Only use the first configuration found.
549 	 */
550 }
551 
552 static void __init smp_reserve_memory(struct mpf_intel *mpf)
553 {
554 	memblock_reserve(mpf->physptr, get_mpc_size(mpf->physptr));
555 }
556 
557 static int __init smp_scan_config(unsigned long base, unsigned long length)
558 {
559 	unsigned int *bp = phys_to_virt(base);
560 	struct mpf_intel *mpf;
561 	unsigned long mem;
562 
563 	apic_printk(APIC_VERBOSE, "Scan for SMP in [mem %#010lx-%#010lx]\n",
564 		    base, base + length - 1);
565 	BUILD_BUG_ON(sizeof(*mpf) != 16);
566 
567 	while (length > 0) {
568 		mpf = (struct mpf_intel *)bp;
569 		if ((*bp == SMP_MAGIC_IDENT) &&
570 		    (mpf->length == 1) &&
571 		    !mpf_checksum((unsigned char *)bp, 16) &&
572 		    ((mpf->specification == 1)
573 		     || (mpf->specification == 4))) {
574 #ifdef CONFIG_X86_LOCAL_APIC
575 			smp_found_config = 1;
576 #endif
577 			mpf_found = mpf;
578 
579 			pr_info("found SMP MP-table at [mem %#010llx-%#010llx] mapped at [%p]\n",
580 				(unsigned long long) virt_to_phys(mpf),
581 				(unsigned long long) virt_to_phys(mpf) +
582 				sizeof(*mpf) - 1, mpf);
583 
584 			mem = virt_to_phys(mpf);
585 			memblock_reserve(mem, sizeof(*mpf));
586 			if (mpf->physptr)
587 				smp_reserve_memory(mpf);
588 
589 			return 1;
590 		}
591 		bp += 4;
592 		length -= 16;
593 	}
594 	return 0;
595 }
596 
597 void __init default_find_smp_config(void)
598 {
599 	unsigned int address;
600 
601 	/*
602 	 * FIXME: Linux assumes you have 640K of base ram..
603 	 * this continues the error...
604 	 *
605 	 * 1) Scan the bottom 1K for a signature
606 	 * 2) Scan the top 1K of base RAM
607 	 * 3) Scan the 64K of bios
608 	 */
609 	if (smp_scan_config(0x0, 0x400) ||
610 	    smp_scan_config(639 * 0x400, 0x400) ||
611 	    smp_scan_config(0xF0000, 0x10000))
612 		return;
613 	/*
614 	 * If it is an SMP machine we should know now, unless the
615 	 * configuration is in an EISA bus machine with an
616 	 * extended bios data area.
617 	 *
618 	 * there is a real-mode segmented pointer pointing to the
619 	 * 4K EBDA area at 0x40E, calculate and scan it here.
620 	 *
621 	 * NOTE! There are Linux loaders that will corrupt the EBDA
622 	 * area, and as such this kind of SMP config may be less
623 	 * trustworthy, simply because the SMP table may have been
624 	 * stomped on during early boot. These loaders are buggy and
625 	 * should be fixed.
626 	 *
627 	 * MP1.4 SPEC states to only scan first 1K of 4K EBDA.
628 	 */
629 
630 	address = get_bios_ebda();
631 	if (address)
632 		smp_scan_config(address, 0x400);
633 }
634 
635 #ifdef CONFIG_X86_IO_APIC
636 static u8 __initdata irq_used[MAX_IRQ_SOURCES];
637 
638 static int  __init get_MP_intsrc_index(struct mpc_intsrc *m)
639 {
640 	int i;
641 
642 	if (m->irqtype != mp_INT)
643 		return 0;
644 
645 	if (m->irqflag != 0x0f)
646 		return 0;
647 
648 	/* not legacy */
649 
650 	for (i = 0; i < mp_irq_entries; i++) {
651 		if (mp_irqs[i].irqtype != mp_INT)
652 			continue;
653 
654 		if (mp_irqs[i].irqflag != 0x0f)
655 			continue;
656 
657 		if (mp_irqs[i].srcbus != m->srcbus)
658 			continue;
659 		if (mp_irqs[i].srcbusirq != m->srcbusirq)
660 			continue;
661 		if (irq_used[i]) {
662 			/* already claimed */
663 			return -2;
664 		}
665 		irq_used[i] = 1;
666 		return i;
667 	}
668 
669 	/* not found */
670 	return -1;
671 }
672 
673 #define SPARE_SLOT_NUM 20
674 
675 static struct mpc_intsrc __initdata *m_spare[SPARE_SLOT_NUM];
676 
677 static void __init check_irq_src(struct mpc_intsrc *m, int *nr_m_spare)
678 {
679 	int i;
680 
681 	apic_printk(APIC_VERBOSE, "OLD ");
682 	print_mp_irq_info(m);
683 
684 	i = get_MP_intsrc_index(m);
685 	if (i > 0) {
686 		memcpy(m, &mp_irqs[i], sizeof(*m));
687 		apic_printk(APIC_VERBOSE, "NEW ");
688 		print_mp_irq_info(&mp_irqs[i]);
689 		return;
690 	}
691 	if (!i) {
692 		/* legacy, do nothing */
693 		return;
694 	}
695 	if (*nr_m_spare < SPARE_SLOT_NUM) {
696 		/*
697 		 * not found (-1), or duplicated (-2) are invalid entries,
698 		 * we need to use the slot later
699 		 */
700 		m_spare[*nr_m_spare] = m;
701 		*nr_m_spare += 1;
702 	}
703 }
704 
705 static int __init
706 check_slot(unsigned long mpc_new_phys, unsigned long mpc_new_length, int count)
707 {
708 	if (!mpc_new_phys || count <= mpc_new_length) {
709 		WARN(1, "update_mptable: No spare slots (length: %x)\n", count);
710 		return -1;
711 	}
712 
713 	return 0;
714 }
715 #else /* CONFIG_X86_IO_APIC */
716 static
717 inline void __init check_irq_src(struct mpc_intsrc *m, int *nr_m_spare) {}
718 #endif /* CONFIG_X86_IO_APIC */
719 
720 static int  __init replace_intsrc_all(struct mpc_table *mpc,
721 					unsigned long mpc_new_phys,
722 					unsigned long mpc_new_length)
723 {
724 #ifdef CONFIG_X86_IO_APIC
725 	int i;
726 #endif
727 	int count = sizeof(*mpc);
728 	int nr_m_spare = 0;
729 	unsigned char *mpt = ((unsigned char *)mpc) + count;
730 
731 	pr_info("mpc_length %x\n", mpc->length);
732 	while (count < mpc->length) {
733 		switch (*mpt) {
734 		case MP_PROCESSOR:
735 			skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
736 			break;
737 		case MP_BUS:
738 			skip_entry(&mpt, &count, sizeof(struct mpc_bus));
739 			break;
740 		case MP_IOAPIC:
741 			skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
742 			break;
743 		case MP_INTSRC:
744 			check_irq_src((struct mpc_intsrc *)mpt, &nr_m_spare);
745 			skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
746 			break;
747 		case MP_LINTSRC:
748 			skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
749 			break;
750 		default:
751 			/* wrong mptable */
752 			smp_dump_mptable(mpc, mpt);
753 			goto out;
754 		}
755 	}
756 
757 #ifdef CONFIG_X86_IO_APIC
758 	for (i = 0; i < mp_irq_entries; i++) {
759 		if (irq_used[i])
760 			continue;
761 
762 		if (mp_irqs[i].irqtype != mp_INT)
763 			continue;
764 
765 		if (mp_irqs[i].irqflag != 0x0f)
766 			continue;
767 
768 		if (nr_m_spare > 0) {
769 			apic_printk(APIC_VERBOSE, "*NEW* found\n");
770 			nr_m_spare--;
771 			memcpy(m_spare[nr_m_spare], &mp_irqs[i], sizeof(mp_irqs[i]));
772 			m_spare[nr_m_spare] = NULL;
773 		} else {
774 			struct mpc_intsrc *m = (struct mpc_intsrc *)mpt;
775 			count += sizeof(struct mpc_intsrc);
776 			if (check_slot(mpc_new_phys, mpc_new_length, count) < 0)
777 				goto out;
778 			memcpy(m, &mp_irqs[i], sizeof(*m));
779 			mpc->length = count;
780 			mpt += sizeof(struct mpc_intsrc);
781 		}
782 		print_mp_irq_info(&mp_irqs[i]);
783 	}
784 #endif
785 out:
786 	/* update checksum */
787 	mpc->checksum = 0;
788 	mpc->checksum -= mpf_checksum((unsigned char *)mpc, mpc->length);
789 
790 	return 0;
791 }
792 
793 int enable_update_mptable;
794 
795 static int __init update_mptable_setup(char *str)
796 {
797 	enable_update_mptable = 1;
798 #ifdef CONFIG_PCI
799 	pci_routeirq = 1;
800 #endif
801 	return 0;
802 }
803 early_param("update_mptable", update_mptable_setup);
804 
805 static unsigned long __initdata mpc_new_phys;
806 static unsigned long mpc_new_length __initdata = 4096;
807 
808 /* alloc_mptable or alloc_mptable=4k */
809 static int __initdata alloc_mptable;
810 static int __init parse_alloc_mptable_opt(char *p)
811 {
812 	enable_update_mptable = 1;
813 #ifdef CONFIG_PCI
814 	pci_routeirq = 1;
815 #endif
816 	alloc_mptable = 1;
817 	if (!p)
818 		return 0;
819 	mpc_new_length = memparse(p, &p);
820 	return 0;
821 }
822 early_param("alloc_mptable", parse_alloc_mptable_opt);
823 
824 void __init early_reserve_e820_mpc_new(void)
825 {
826 	if (enable_update_mptable && alloc_mptable)
827 		mpc_new_phys = early_reserve_e820(mpc_new_length, 4);
828 }
829 
830 static int __init update_mp_table(void)
831 {
832 	char str[16];
833 	char oem[10];
834 	struct mpf_intel *mpf;
835 	struct mpc_table *mpc, *mpc_new;
836 
837 	if (!enable_update_mptable)
838 		return 0;
839 
840 	mpf = mpf_found;
841 	if (!mpf)
842 		return 0;
843 
844 	/*
845 	 * Now see if we need to go further.
846 	 */
847 	if (mpf->feature1 != 0)
848 		return 0;
849 
850 	if (!mpf->physptr)
851 		return 0;
852 
853 	mpc = phys_to_virt(mpf->physptr);
854 
855 	if (!smp_check_mpc(mpc, oem, str))
856 		return 0;
857 
858 	pr_info("mpf: %llx\n", (u64)virt_to_phys(mpf));
859 	pr_info("physptr: %x\n", mpf->physptr);
860 
861 	if (mpc_new_phys && mpc->length > mpc_new_length) {
862 		mpc_new_phys = 0;
863 		pr_info("mpc_new_length is %ld, please use alloc_mptable=8k\n",
864 			mpc_new_length);
865 	}
866 
867 	if (!mpc_new_phys) {
868 		unsigned char old, new;
869 		/* check if we can change the position */
870 		mpc->checksum = 0;
871 		old = mpf_checksum((unsigned char *)mpc, mpc->length);
872 		mpc->checksum = 0xff;
873 		new = mpf_checksum((unsigned char *)mpc, mpc->length);
874 		if (old == new) {
875 			pr_info("mpc is readonly, please try alloc_mptable instead\n");
876 			return 0;
877 		}
878 		pr_info("use in-position replacing\n");
879 	} else {
880 		mpf->physptr = mpc_new_phys;
881 		mpc_new = phys_to_virt(mpc_new_phys);
882 		memcpy(mpc_new, mpc, mpc->length);
883 		mpc = mpc_new;
884 		/* check if we can modify that */
885 		if (mpc_new_phys - mpf->physptr) {
886 			struct mpf_intel *mpf_new;
887 			/* steal 16 bytes from [0, 1k) */
888 			pr_info("mpf new: %x\n", 0x400 - 16);
889 			mpf_new = phys_to_virt(0x400 - 16);
890 			memcpy(mpf_new, mpf, 16);
891 			mpf = mpf_new;
892 			mpf->physptr = mpc_new_phys;
893 		}
894 		mpf->checksum = 0;
895 		mpf->checksum -= mpf_checksum((unsigned char *)mpf, 16);
896 		pr_info("physptr new: %x\n", mpf->physptr);
897 	}
898 
899 	/*
900 	 * only replace the one with mp_INT and
901 	 *	 MP_IRQ_TRIGGER_LEVEL|MP_IRQ_POLARITY_LOW,
902 	 * already in mp_irqs , stored by ... and mp_config_acpi_gsi,
903 	 * may need pci=routeirq for all coverage
904 	 */
905 	replace_intsrc_all(mpc, mpc_new_phys, mpc_new_length);
906 
907 	return 0;
908 }
909 
910 late_initcall(update_mp_table);
911