xref: /openbmc/linux/arch/x86/kernel/mpparse.c (revision 565d76cb)
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/trampoline.h>
31 #include <asm/setup.h>
32 #include <asm/smp.h>
33 
34 #include <asm/apic.h>
35 /*
36  * Checksum an MP configuration block.
37  */
38 
39 static int __init mpf_checksum(unsigned char *mp, int len)
40 {
41 	int sum = 0;
42 
43 	while (len--)
44 		sum += *mp++;
45 
46 	return sum & 0xFF;
47 }
48 
49 int __init default_mpc_apic_id(struct mpc_cpu *m)
50 {
51 	return m->apicid;
52 }
53 
54 static void __init MP_processor_info(struct mpc_cpu *m)
55 {
56 	int apicid;
57 	char *bootup_cpu = "";
58 
59 	if (!(m->cpuflag & CPU_ENABLED)) {
60 		disabled_cpus++;
61 		return;
62 	}
63 
64 	apicid = x86_init.mpparse.mpc_apic_id(m);
65 
66 	if (m->cpuflag & CPU_BOOTPROCESSOR) {
67 		bootup_cpu = " (Bootup-CPU)";
68 		boot_cpu_physical_apicid = m->apicid;
69 	}
70 
71 	printk(KERN_INFO "Processor #%d%s\n", m->apicid, bootup_cpu);
72 	generic_processor_info(apicid, m->apicver);
73 }
74 
75 #ifdef CONFIG_X86_IO_APIC
76 void __init default_mpc_oem_bus_info(struct mpc_bus *m, char *str)
77 {
78 	memcpy(str, m->bustype, 6);
79 	str[6] = 0;
80 	apic_printk(APIC_VERBOSE, "Bus #%d is %s\n", m->busid, str);
81 }
82 
83 static void __init MP_bus_info(struct mpc_bus *m)
84 {
85 	char str[7];
86 
87 	x86_init.mpparse.mpc_oem_bus_info(m, str);
88 
89 #if MAX_MP_BUSSES < 256
90 	if (m->busid >= MAX_MP_BUSSES) {
91 		printk(KERN_WARNING "MP table busid value (%d) for bustype %s "
92 		       " is too large, max. supported is %d\n",
93 		       m->busid, str, MAX_MP_BUSSES - 1);
94 		return;
95 	}
96 #endif
97 
98 	if (strncmp(str, BUSTYPE_ISA, sizeof(BUSTYPE_ISA) - 1) == 0) {
99 		set_bit(m->busid, mp_bus_not_pci);
100 #if defined(CONFIG_EISA) || defined(CONFIG_MCA)
101 		mp_bus_id_to_type[m->busid] = MP_BUS_ISA;
102 #endif
103 	} else if (strncmp(str, BUSTYPE_PCI, sizeof(BUSTYPE_PCI) - 1) == 0) {
104 		if (x86_init.mpparse.mpc_oem_pci_bus)
105 			x86_init.mpparse.mpc_oem_pci_bus(m);
106 
107 		clear_bit(m->busid, mp_bus_not_pci);
108 #if defined(CONFIG_EISA) || defined(CONFIG_MCA)
109 		mp_bus_id_to_type[m->busid] = MP_BUS_PCI;
110 	} else if (strncmp(str, BUSTYPE_EISA, sizeof(BUSTYPE_EISA) - 1) == 0) {
111 		mp_bus_id_to_type[m->busid] = MP_BUS_EISA;
112 	} else if (strncmp(str, BUSTYPE_MCA, sizeof(BUSTYPE_MCA) - 1) == 0) {
113 		mp_bus_id_to_type[m->busid] = MP_BUS_MCA;
114 #endif
115 	} else
116 		printk(KERN_WARNING "Unknown bustype %s - ignoring\n", str);
117 }
118 
119 static void __init MP_ioapic_info(struct mpc_ioapic *m)
120 {
121 	if (m->flags & MPC_APIC_USABLE)
122 		mp_register_ioapic(m->apicid, m->apicaddr, gsi_top);
123 }
124 
125 static void __init print_mp_irq_info(struct mpc_intsrc *mp_irq)
126 {
127 	apic_printk(APIC_VERBOSE, "Int: type %d, pol %d, trig %d, bus %02x,"
128 		" IRQ %02x, APIC ID %x, APIC INT %02x\n",
129 		mp_irq->irqtype, mp_irq->irqflag & 3,
130 		(mp_irq->irqflag >> 2) & 3, mp_irq->srcbus,
131 		mp_irq->srcbusirq, mp_irq->dstapic, mp_irq->dstirq);
132 }
133 
134 #else /* CONFIG_X86_IO_APIC */
135 static inline void __init MP_bus_info(struct mpc_bus *m) {}
136 static inline void __init MP_ioapic_info(struct mpc_ioapic *m) {}
137 #endif /* CONFIG_X86_IO_APIC */
138 
139 static void __init MP_lintsrc_info(struct mpc_lintsrc *m)
140 {
141 	apic_printk(APIC_VERBOSE, "Lint: type %d, pol %d, trig %d, bus %02x,"
142 		" IRQ %02x, APIC ID %x, APIC LINT %02x\n",
143 		m->irqtype, m->irqflag & 3, (m->irqflag >> 2) & 3, m->srcbusid,
144 		m->srcbusirq, m->destapic, m->destapiclint);
145 }
146 
147 /*
148  * Read/parse the MPC
149  */
150 static int __init smp_check_mpc(struct mpc_table *mpc, char *oem, char *str)
151 {
152 
153 	if (memcmp(mpc->signature, MPC_SIGNATURE, 4)) {
154 		printk(KERN_ERR "MPTABLE: bad signature [%c%c%c%c]!\n",
155 		       mpc->signature[0], mpc->signature[1],
156 		       mpc->signature[2], mpc->signature[3]);
157 		return 0;
158 	}
159 	if (mpf_checksum((unsigned char *)mpc, mpc->length)) {
160 		printk(KERN_ERR "MPTABLE: checksum error!\n");
161 		return 0;
162 	}
163 	if (mpc->spec != 0x01 && mpc->spec != 0x04) {
164 		printk(KERN_ERR "MPTABLE: bad table version (%d)!!\n",
165 		       mpc->spec);
166 		return 0;
167 	}
168 	if (!mpc->lapic) {
169 		printk(KERN_ERR "MPTABLE: null local APIC address!\n");
170 		return 0;
171 	}
172 	memcpy(oem, mpc->oem, 8);
173 	oem[8] = 0;
174 	printk(KERN_INFO "MPTABLE: OEM ID: %s\n", oem);
175 
176 	memcpy(str, mpc->productid, 12);
177 	str[12] = 0;
178 
179 	printk(KERN_INFO "MPTABLE: Product ID: %s\n", str);
180 
181 	printk(KERN_INFO "MPTABLE: APIC at: 0x%X\n", mpc->lapic);
182 
183 	return 1;
184 }
185 
186 static void skip_entry(unsigned char **ptr, int *count, int size)
187 {
188 	*ptr += size;
189 	*count += size;
190 }
191 
192 static void __init smp_dump_mptable(struct mpc_table *mpc, unsigned char *mpt)
193 {
194 	printk(KERN_ERR "Your mptable is wrong, contact your HW vendor!\n"
195 		"type %x\n", *mpt);
196 	print_hex_dump(KERN_ERR, "  ", DUMP_PREFIX_ADDRESS, 16,
197 			1, mpc, mpc->length, 1);
198 }
199 
200 void __init default_smp_read_mpc_oem(struct mpc_table *mpc) { }
201 
202 static int __init smp_read_mpc(struct mpc_table *mpc, unsigned early)
203 {
204 	char str[16];
205 	char oem[10];
206 
207 	int count = sizeof(*mpc);
208 	unsigned char *mpt = ((unsigned char *)mpc) + count;
209 
210 	if (!smp_check_mpc(mpc, oem, str))
211 		return 0;
212 
213 #ifdef CONFIG_X86_32
214 	generic_mps_oem_check(mpc, oem, str);
215 #endif
216 	/* Initialize the lapic mapping */
217 	if (!acpi_lapic)
218 		register_lapic_address(mpc->lapic);
219 
220 	if (early)
221 		return 1;
222 
223 	if (mpc->oemptr)
224 		x86_init.mpparse.smp_read_mpc_oem(mpc);
225 
226 	/*
227 	 *      Now process the configuration blocks.
228 	 */
229 	x86_init.mpparse.mpc_record(0);
230 
231 	while (count < mpc->length) {
232 		switch (*mpt) {
233 		case MP_PROCESSOR:
234 			/* ACPI may have already provided this data */
235 			if (!acpi_lapic)
236 				MP_processor_info((struct mpc_cpu *)mpt);
237 			skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
238 			break;
239 		case MP_BUS:
240 			MP_bus_info((struct mpc_bus *)mpt);
241 			skip_entry(&mpt, &count, sizeof(struct mpc_bus));
242 			break;
243 		case MP_IOAPIC:
244 			MP_ioapic_info((struct mpc_ioapic *)mpt);
245 			skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
246 			break;
247 		case MP_INTSRC:
248 			mp_save_irq((struct mpc_intsrc *)mpt);
249 			skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
250 			break;
251 		case MP_LINTSRC:
252 			MP_lintsrc_info((struct mpc_lintsrc *)mpt);
253 			skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
254 			break;
255 		default:
256 			/* wrong mptable */
257 			smp_dump_mptable(mpc, mpt);
258 			count = mpc->length;
259 			break;
260 		}
261 		x86_init.mpparse.mpc_record(1);
262 	}
263 
264 	if (!num_processors)
265 		printk(KERN_ERR "MPTABLE: no processors registered!\n");
266 	return num_processors;
267 }
268 
269 #ifdef CONFIG_X86_IO_APIC
270 
271 static int __init ELCR_trigger(unsigned int irq)
272 {
273 	unsigned int port;
274 
275 	port = 0x4d0 + (irq >> 3);
276 	return (inb(port) >> (irq & 7)) & 1;
277 }
278 
279 static void __init construct_default_ioirq_mptable(int mpc_default_type)
280 {
281 	struct mpc_intsrc intsrc;
282 	int i;
283 	int ELCR_fallback = 0;
284 
285 	intsrc.type = MP_INTSRC;
286 	intsrc.irqflag = 0;	/* conforming */
287 	intsrc.srcbus = 0;
288 	intsrc.dstapic = mp_ioapics[0].apicid;
289 
290 	intsrc.irqtype = mp_INT;
291 
292 	/*
293 	 *  If true, we have an ISA/PCI system with no IRQ entries
294 	 *  in the MP table. To prevent the PCI interrupts from being set up
295 	 *  incorrectly, we try to use the ELCR. The sanity check to see if
296 	 *  there is good ELCR data is very simple - IRQ0, 1, 2 and 13 can
297 	 *  never be level sensitive, so we simply see if the ELCR agrees.
298 	 *  If it does, we assume it's valid.
299 	 */
300 	if (mpc_default_type == 5) {
301 		printk(KERN_INFO "ISA/PCI bus type with no IRQ information... "
302 		       "falling back to ELCR\n");
303 
304 		if (ELCR_trigger(0) || ELCR_trigger(1) || ELCR_trigger(2) ||
305 		    ELCR_trigger(13))
306 			printk(KERN_ERR "ELCR contains invalid data... "
307 			       "not using ELCR\n");
308 		else {
309 			printk(KERN_INFO
310 			       "Using ELCR to identify PCI interrupts\n");
311 			ELCR_fallback = 1;
312 		}
313 	}
314 
315 	for (i = 0; i < 16; i++) {
316 		switch (mpc_default_type) {
317 		case 2:
318 			if (i == 0 || i == 13)
319 				continue;	/* IRQ0 & IRQ13 not connected */
320 			/* fall through */
321 		default:
322 			if (i == 2)
323 				continue;	/* IRQ2 is never connected */
324 		}
325 
326 		if (ELCR_fallback) {
327 			/*
328 			 *  If the ELCR indicates a level-sensitive interrupt, we
329 			 *  copy that information over to the MP table in the
330 			 *  irqflag field (level sensitive, active high polarity).
331 			 */
332 			if (ELCR_trigger(i))
333 				intsrc.irqflag = 13;
334 			else
335 				intsrc.irqflag = 0;
336 		}
337 
338 		intsrc.srcbusirq = i;
339 		intsrc.dstirq = i ? i : 2;	/* IRQ0 to INTIN2 */
340 		mp_save_irq(&intsrc);
341 	}
342 
343 	intsrc.irqtype = mp_ExtINT;
344 	intsrc.srcbusirq = 0;
345 	intsrc.dstirq = 0;	/* 8259A to INTIN0 */
346 	mp_save_irq(&intsrc);
347 }
348 
349 
350 static void __init construct_ioapic_table(int mpc_default_type)
351 {
352 	struct mpc_ioapic ioapic;
353 	struct mpc_bus bus;
354 
355 	bus.type = MP_BUS;
356 	bus.busid = 0;
357 	switch (mpc_default_type) {
358 	default:
359 		printk(KERN_ERR "???\nUnknown standard configuration %d\n",
360 		       mpc_default_type);
361 		/* fall through */
362 	case 1:
363 	case 5:
364 		memcpy(bus.bustype, "ISA   ", 6);
365 		break;
366 	case 2:
367 	case 6:
368 	case 3:
369 		memcpy(bus.bustype, "EISA  ", 6);
370 		break;
371 	case 4:
372 	case 7:
373 		memcpy(bus.bustype, "MCA   ", 6);
374 	}
375 	MP_bus_info(&bus);
376 	if (mpc_default_type > 4) {
377 		bus.busid = 1;
378 		memcpy(bus.bustype, "PCI   ", 6);
379 		MP_bus_info(&bus);
380 	}
381 
382 	ioapic.type	= MP_IOAPIC;
383 	ioapic.apicid	= 2;
384 	ioapic.apicver	= mpc_default_type > 4 ? 0x10 : 0x01;
385 	ioapic.flags	= MPC_APIC_USABLE;
386 	ioapic.apicaddr	= IO_APIC_DEFAULT_PHYS_BASE;
387 	MP_ioapic_info(&ioapic);
388 
389 	/*
390 	 * We set up most of the low 16 IO-APIC pins according to MPS rules.
391 	 */
392 	construct_default_ioirq_mptable(mpc_default_type);
393 }
394 #else
395 static inline void __init construct_ioapic_table(int mpc_default_type) { }
396 #endif
397 
398 static inline void __init construct_default_ISA_mptable(int mpc_default_type)
399 {
400 	struct mpc_cpu processor;
401 	struct mpc_lintsrc lintsrc;
402 	int linttypes[2] = { mp_ExtINT, mp_NMI };
403 	int i;
404 
405 	/*
406 	 * local APIC has default address
407 	 */
408 	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
409 
410 	/*
411 	 * 2 CPUs, numbered 0 & 1.
412 	 */
413 	processor.type = MP_PROCESSOR;
414 	/* Either an integrated APIC or a discrete 82489DX. */
415 	processor.apicver = mpc_default_type > 4 ? 0x10 : 0x01;
416 	processor.cpuflag = CPU_ENABLED;
417 	processor.cpufeature = (boot_cpu_data.x86 << 8) |
418 	    (boot_cpu_data.x86_model << 4) | boot_cpu_data.x86_mask;
419 	processor.featureflag = boot_cpu_data.x86_capability[0];
420 	processor.reserved[0] = 0;
421 	processor.reserved[1] = 0;
422 	for (i = 0; i < 2; i++) {
423 		processor.apicid = i;
424 		MP_processor_info(&processor);
425 	}
426 
427 	construct_ioapic_table(mpc_default_type);
428 
429 	lintsrc.type = MP_LINTSRC;
430 	lintsrc.irqflag = 0;		/* conforming */
431 	lintsrc.srcbusid = 0;
432 	lintsrc.srcbusirq = 0;
433 	lintsrc.destapic = MP_APIC_ALL;
434 	for (i = 0; i < 2; i++) {
435 		lintsrc.irqtype = linttypes[i];
436 		lintsrc.destapiclint = i;
437 		MP_lintsrc_info(&lintsrc);
438 	}
439 }
440 
441 static struct mpf_intel *mpf_found;
442 
443 static unsigned long __init get_mpc_size(unsigned long physptr)
444 {
445 	struct mpc_table *mpc;
446 	unsigned long size;
447 
448 	mpc = early_ioremap(physptr, PAGE_SIZE);
449 	size = mpc->length;
450 	early_iounmap(mpc, PAGE_SIZE);
451 	apic_printk(APIC_VERBOSE, "  mpc: %lx-%lx\n", physptr, physptr + size);
452 
453 	return size;
454 }
455 
456 static int __init check_physptr(struct mpf_intel *mpf, unsigned int early)
457 {
458 	struct mpc_table *mpc;
459 	unsigned long size;
460 
461 	size = get_mpc_size(mpf->physptr);
462 	mpc = early_ioremap(mpf->physptr, size);
463 	/*
464 	 * Read the physical hardware table.  Anything here will
465 	 * override the defaults.
466 	 */
467 	if (!smp_read_mpc(mpc, early)) {
468 #ifdef CONFIG_X86_LOCAL_APIC
469 		smp_found_config = 0;
470 #endif
471 		printk(KERN_ERR "BIOS bug, MP table errors detected!...\n"
472 			"... disabling SMP support. (tell your hw vendor)\n");
473 		early_iounmap(mpc, size);
474 		return -1;
475 	}
476 	early_iounmap(mpc, size);
477 
478 	if (early)
479 		return -1;
480 
481 #ifdef CONFIG_X86_IO_APIC
482 	/*
483 	 * If there are no explicit MP IRQ entries, then we are
484 	 * broken.  We set up most of the low 16 IO-APIC pins to
485 	 * ISA defaults and hope it will work.
486 	 */
487 	if (!mp_irq_entries) {
488 		struct mpc_bus bus;
489 
490 		printk(KERN_ERR "BIOS bug, no explicit IRQ entries, "
491 		       "using default mptable. (tell your hw vendor)\n");
492 
493 		bus.type = MP_BUS;
494 		bus.busid = 0;
495 		memcpy(bus.bustype, "ISA   ", 6);
496 		MP_bus_info(&bus);
497 
498 		construct_default_ioirq_mptable(0);
499 	}
500 #endif
501 
502 	return 0;
503 }
504 
505 /*
506  * Scan the memory blocks for an SMP configuration block.
507  */
508 void __init default_get_smp_config(unsigned int early)
509 {
510 	struct mpf_intel *mpf = mpf_found;
511 
512 	if (!mpf)
513 		return;
514 
515 	if (acpi_lapic && early)
516 		return;
517 
518 	/*
519 	 * MPS doesn't support hyperthreading, aka only have
520 	 * thread 0 apic id in MPS table
521 	 */
522 	if (acpi_lapic && acpi_ioapic)
523 		return;
524 
525 	printk(KERN_INFO "Intel MultiProcessor Specification v1.%d\n",
526 	       mpf->specification);
527 #if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_32)
528 	if (mpf->feature2 & (1 << 7)) {
529 		printk(KERN_INFO "    IMCR and PIC compatibility mode.\n");
530 		pic_mode = 1;
531 	} else {
532 		printk(KERN_INFO "    Virtual Wire compatibility mode.\n");
533 		pic_mode = 0;
534 	}
535 #endif
536 	/*
537 	 * Now see if we need to read further.
538 	 */
539 	if (mpf->feature1 != 0) {
540 		if (early) {
541 			/*
542 			 * local APIC has default address
543 			 */
544 			mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
545 			return;
546 		}
547 
548 		printk(KERN_INFO "Default MP configuration #%d\n",
549 		       mpf->feature1);
550 		construct_default_ISA_mptable(mpf->feature1);
551 
552 	} else if (mpf->physptr) {
553 		if (check_physptr(mpf, early))
554 			return;
555 	} else
556 		BUG();
557 
558 	if (!early)
559 		printk(KERN_INFO "Processors: %d\n", num_processors);
560 	/*
561 	 * Only use the first configuration found.
562 	 */
563 }
564 
565 static void __init smp_reserve_memory(struct mpf_intel *mpf)
566 {
567 	unsigned long size = get_mpc_size(mpf->physptr);
568 
569 	memblock_x86_reserve_range(mpf->physptr, mpf->physptr+size, "* MP-table mpc");
570 }
571 
572 static int __init smp_scan_config(unsigned long base, unsigned long length)
573 {
574 	unsigned int *bp = phys_to_virt(base);
575 	struct mpf_intel *mpf;
576 	unsigned long mem;
577 
578 	apic_printk(APIC_VERBOSE, "Scan SMP from %p for %ld bytes.\n",
579 			bp, length);
580 	BUILD_BUG_ON(sizeof(*mpf) != 16);
581 
582 	while (length > 0) {
583 		mpf = (struct mpf_intel *)bp;
584 		if ((*bp == SMP_MAGIC_IDENT) &&
585 		    (mpf->length == 1) &&
586 		    !mpf_checksum((unsigned char *)bp, 16) &&
587 		    ((mpf->specification == 1)
588 		     || (mpf->specification == 4))) {
589 #ifdef CONFIG_X86_LOCAL_APIC
590 			smp_found_config = 1;
591 #endif
592 			mpf_found = mpf;
593 
594 			printk(KERN_INFO "found SMP MP-table at [%p] %llx\n",
595 			       mpf, (u64)virt_to_phys(mpf));
596 
597 			mem = virt_to_phys(mpf);
598 			memblock_x86_reserve_range(mem, mem + sizeof(*mpf), "* MP-table mpf");
599 			if (mpf->physptr)
600 				smp_reserve_memory(mpf);
601 
602 			return 1;
603 		}
604 		bp += 4;
605 		length -= 16;
606 	}
607 	return 0;
608 }
609 
610 void __init default_find_smp_config(void)
611 {
612 	unsigned int address;
613 
614 	/*
615 	 * FIXME: Linux assumes you have 640K of base ram..
616 	 * this continues the error...
617 	 *
618 	 * 1) Scan the bottom 1K for a signature
619 	 * 2) Scan the top 1K of base RAM
620 	 * 3) Scan the 64K of bios
621 	 */
622 	if (smp_scan_config(0x0, 0x400) ||
623 	    smp_scan_config(639 * 0x400, 0x400) ||
624 	    smp_scan_config(0xF0000, 0x10000))
625 		return;
626 	/*
627 	 * If it is an SMP machine we should know now, unless the
628 	 * configuration is in an EISA/MCA bus machine with an
629 	 * extended bios data area.
630 	 *
631 	 * there is a real-mode segmented pointer pointing to the
632 	 * 4K EBDA area at 0x40E, calculate and scan it here.
633 	 *
634 	 * NOTE! There are Linux loaders that will corrupt the EBDA
635 	 * area, and as such this kind of SMP config may be less
636 	 * trustworthy, simply because the SMP table may have been
637 	 * stomped on during early boot. These loaders are buggy and
638 	 * should be fixed.
639 	 *
640 	 * MP1.4 SPEC states to only scan first 1K of 4K EBDA.
641 	 */
642 
643 	address = get_bios_ebda();
644 	if (address)
645 		smp_scan_config(address, 0x400);
646 }
647 
648 #ifdef CONFIG_X86_IO_APIC
649 static u8 __initdata irq_used[MAX_IRQ_SOURCES];
650 
651 static int  __init get_MP_intsrc_index(struct mpc_intsrc *m)
652 {
653 	int i;
654 
655 	if (m->irqtype != mp_INT)
656 		return 0;
657 
658 	if (m->irqflag != 0x0f)
659 		return 0;
660 
661 	/* not legacy */
662 
663 	for (i = 0; i < mp_irq_entries; i++) {
664 		if (mp_irqs[i].irqtype != mp_INT)
665 			continue;
666 
667 		if (mp_irqs[i].irqflag != 0x0f)
668 			continue;
669 
670 		if (mp_irqs[i].srcbus != m->srcbus)
671 			continue;
672 		if (mp_irqs[i].srcbusirq != m->srcbusirq)
673 			continue;
674 		if (irq_used[i]) {
675 			/* already claimed */
676 			return -2;
677 		}
678 		irq_used[i] = 1;
679 		return i;
680 	}
681 
682 	/* not found */
683 	return -1;
684 }
685 
686 #define SPARE_SLOT_NUM 20
687 
688 static struct mpc_intsrc __initdata *m_spare[SPARE_SLOT_NUM];
689 
690 static void __init check_irq_src(struct mpc_intsrc *m, int *nr_m_spare)
691 {
692 	int i;
693 
694 	apic_printk(APIC_VERBOSE, "OLD ");
695 	print_mp_irq_info(m);
696 
697 	i = get_MP_intsrc_index(m);
698 	if (i > 0) {
699 		memcpy(m, &mp_irqs[i], sizeof(*m));
700 		apic_printk(APIC_VERBOSE, "NEW ");
701 		print_mp_irq_info(&mp_irqs[i]);
702 		return;
703 	}
704 	if (!i) {
705 		/* legacy, do nothing */
706 		return;
707 	}
708 	if (*nr_m_spare < SPARE_SLOT_NUM) {
709 		/*
710 		 * not found (-1), or duplicated (-2) are invalid entries,
711 		 * we need to use the slot later
712 		 */
713 		m_spare[*nr_m_spare] = m;
714 		*nr_m_spare += 1;
715 	}
716 }
717 #else /* CONFIG_X86_IO_APIC */
718 static
719 inline void __init check_irq_src(struct mpc_intsrc *m, int *nr_m_spare) {}
720 #endif /* CONFIG_X86_IO_APIC */
721 
722 static int
723 check_slot(unsigned long mpc_new_phys, unsigned long mpc_new_length, int count)
724 {
725 	int ret = 0;
726 
727 	if (!mpc_new_phys || count <= mpc_new_length) {
728 		WARN(1, "update_mptable: No spare slots (length: %x)\n", count);
729 		return -1;
730 	}
731 
732 	return ret;
733 }
734 
735 static int  __init replace_intsrc_all(struct mpc_table *mpc,
736 					unsigned long mpc_new_phys,
737 					unsigned long mpc_new_length)
738 {
739 #ifdef CONFIG_X86_IO_APIC
740 	int i;
741 #endif
742 	int count = sizeof(*mpc);
743 	int nr_m_spare = 0;
744 	unsigned char *mpt = ((unsigned char *)mpc) + count;
745 
746 	printk(KERN_INFO "mpc_length %x\n", mpc->length);
747 	while (count < mpc->length) {
748 		switch (*mpt) {
749 		case MP_PROCESSOR:
750 			skip_entry(&mpt, &count, sizeof(struct mpc_cpu));
751 			break;
752 		case MP_BUS:
753 			skip_entry(&mpt, &count, sizeof(struct mpc_bus));
754 			break;
755 		case MP_IOAPIC:
756 			skip_entry(&mpt, &count, sizeof(struct mpc_ioapic));
757 			break;
758 		case MP_INTSRC:
759 			check_irq_src((struct mpc_intsrc *)mpt, &nr_m_spare);
760 			skip_entry(&mpt, &count, sizeof(struct mpc_intsrc));
761 			break;
762 		case MP_LINTSRC:
763 			skip_entry(&mpt, &count, sizeof(struct mpc_lintsrc));
764 			break;
765 		default:
766 			/* wrong mptable */
767 			smp_dump_mptable(mpc, mpt);
768 			goto out;
769 		}
770 	}
771 
772 #ifdef CONFIG_X86_IO_APIC
773 	for (i = 0; i < mp_irq_entries; i++) {
774 		if (irq_used[i])
775 			continue;
776 
777 		if (mp_irqs[i].irqtype != mp_INT)
778 			continue;
779 
780 		if (mp_irqs[i].irqflag != 0x0f)
781 			continue;
782 
783 		if (nr_m_spare > 0) {
784 			apic_printk(APIC_VERBOSE, "*NEW* found\n");
785 			nr_m_spare--;
786 			memcpy(m_spare[nr_m_spare], &mp_irqs[i], sizeof(mp_irqs[i]));
787 			m_spare[nr_m_spare] = NULL;
788 		} else {
789 			struct mpc_intsrc *m = (struct mpc_intsrc *)mpt;
790 			count += sizeof(struct mpc_intsrc);
791 			if (check_slot(mpc_new_phys, mpc_new_length, count) < 0)
792 				goto out;
793 			memcpy(m, &mp_irqs[i], sizeof(*m));
794 			mpc->length = count;
795 			mpt += sizeof(struct mpc_intsrc);
796 		}
797 		print_mp_irq_info(&mp_irqs[i]);
798 	}
799 #endif
800 out:
801 	/* update checksum */
802 	mpc->checksum = 0;
803 	mpc->checksum -= mpf_checksum((unsigned char *)mpc, mpc->length);
804 
805 	return 0;
806 }
807 
808 int enable_update_mptable;
809 
810 static int __init update_mptable_setup(char *str)
811 {
812 	enable_update_mptable = 1;
813 #ifdef CONFIG_PCI
814 	pci_routeirq = 1;
815 #endif
816 	return 0;
817 }
818 early_param("update_mptable", update_mptable_setup);
819 
820 static unsigned long __initdata mpc_new_phys;
821 static unsigned long mpc_new_length __initdata = 4096;
822 
823 /* alloc_mptable or alloc_mptable=4k */
824 static int __initdata alloc_mptable;
825 static int __init parse_alloc_mptable_opt(char *p)
826 {
827 	enable_update_mptable = 1;
828 #ifdef CONFIG_PCI
829 	pci_routeirq = 1;
830 #endif
831 	alloc_mptable = 1;
832 	if (!p)
833 		return 0;
834 	mpc_new_length = memparse(p, &p);
835 	return 0;
836 }
837 early_param("alloc_mptable", parse_alloc_mptable_opt);
838 
839 void __init early_reserve_e820_mpc_new(void)
840 {
841 	if (enable_update_mptable && alloc_mptable) {
842 		u64 startt = 0;
843 		mpc_new_phys = early_reserve_e820(startt, mpc_new_length, 4);
844 	}
845 }
846 
847 static int __init update_mp_table(void)
848 {
849 	char str[16];
850 	char oem[10];
851 	struct mpf_intel *mpf;
852 	struct mpc_table *mpc, *mpc_new;
853 
854 	if (!enable_update_mptable)
855 		return 0;
856 
857 	mpf = mpf_found;
858 	if (!mpf)
859 		return 0;
860 
861 	/*
862 	 * Now see if we need to go further.
863 	 */
864 	if (mpf->feature1 != 0)
865 		return 0;
866 
867 	if (!mpf->physptr)
868 		return 0;
869 
870 	mpc = phys_to_virt(mpf->physptr);
871 
872 	if (!smp_check_mpc(mpc, oem, str))
873 		return 0;
874 
875 	printk(KERN_INFO "mpf: %llx\n", (u64)virt_to_phys(mpf));
876 	printk(KERN_INFO "physptr: %x\n", mpf->physptr);
877 
878 	if (mpc_new_phys && mpc->length > mpc_new_length) {
879 		mpc_new_phys = 0;
880 		printk(KERN_INFO "mpc_new_length is %ld, please use alloc_mptable=8k\n",
881 			 mpc_new_length);
882 	}
883 
884 	if (!mpc_new_phys) {
885 		unsigned char old, new;
886 		/* check if we can change the position */
887 		mpc->checksum = 0;
888 		old = mpf_checksum((unsigned char *)mpc, mpc->length);
889 		mpc->checksum = 0xff;
890 		new = mpf_checksum((unsigned char *)mpc, mpc->length);
891 		if (old == new) {
892 			printk(KERN_INFO "mpc is readonly, please try alloc_mptable instead\n");
893 			return 0;
894 		}
895 		printk(KERN_INFO "use in-position replacing\n");
896 	} else {
897 		mpf->physptr = mpc_new_phys;
898 		mpc_new = phys_to_virt(mpc_new_phys);
899 		memcpy(mpc_new, mpc, mpc->length);
900 		mpc = mpc_new;
901 		/* check if we can modify that */
902 		if (mpc_new_phys - mpf->physptr) {
903 			struct mpf_intel *mpf_new;
904 			/* steal 16 bytes from [0, 1k) */
905 			printk(KERN_INFO "mpf new: %x\n", 0x400 - 16);
906 			mpf_new = phys_to_virt(0x400 - 16);
907 			memcpy(mpf_new, mpf, 16);
908 			mpf = mpf_new;
909 			mpf->physptr = mpc_new_phys;
910 		}
911 		mpf->checksum = 0;
912 		mpf->checksum -= mpf_checksum((unsigned char *)mpf, 16);
913 		printk(KERN_INFO "physptr new: %x\n", mpf->physptr);
914 	}
915 
916 	/*
917 	 * only replace the one with mp_INT and
918 	 *	 MP_IRQ_TRIGGER_LEVEL|MP_IRQ_POLARITY_LOW,
919 	 * already in mp_irqs , stored by ... and mp_config_acpi_gsi,
920 	 * may need pci=routeirq for all coverage
921 	 */
922 	replace_intsrc_all(mpc, mpc_new_phys, mpc_new_length);
923 
924 	return 0;
925 }
926 
927 late_initcall(update_mp_table);
928