mpparse.c

这个linux源代码是很全面的~基本完整了~使用c编译的~由于时间问题我没有亲自测试~但就算用来做参考资料也是非常好的

	return num_processors;
}

static int __init ELCR_trigger(unsigned int irq)
{
	unsigned int port;

	port = 0x4d0 + (irq >> 3);
	return (inb(port) >> (irq & 7)) & 1;
}

static void __init construct_default_ioirq_mptable(int mpc_default_type)
{
	struct mpc_config_intsrc intsrc;
	int i;
	int ELCR_fallback = 0;

	intsrc.mpc_type = MP_INTSRC;
	intsrc.mpc_irqflag = 0;			/* conforming */
	intsrc.mpc_srcbus = 0;
	intsrc.mpc_dstapic = mp_ioapics[0].mpc_apicid;

	intsrc.mpc_irqtype = mp_INT;

	/*
	 *  If true, we have an ISA/PCI system with no IRQ entries
	 *  in the MP table. To prevent the PCI interrupts from being set up
	 *  incorrectly, we try to use the ELCR. The sanity check to see if
	 *  there is good ELCR data is very simple - IRQ0, 1, 2 and 13 can
	 *  never be level sensitive, so we simply see if the ELCR agrees.
	 *  If it does, we assume it's valid.
	 */
	if (mpc_default_type == 5) {
		printk("ISA/PCI bus type with no IRQ information... falling back to ELCR\n");

		if (ELCR_trigger(0) || ELCR_trigger(1) || ELCR_trigger(2) || ELCR_trigger(13))
			printk("ELCR contains invalid data... not using ELCR\n");
		else {
			printk("Using ELCR to identify PCI interrupts\n");
			ELCR_fallback = 1;
		}
	}

	for (i = 0; i < 16; i++) {
		switch (mpc_default_type) {
		case 2:
			if (i == 0 || i == 13)
				continue;	/* IRQ0 & IRQ13 not connected */
			/* fall through */
		default:
			if (i == 2)
				continue;	/* IRQ2 is never connected */
		}

		if (ELCR_fallback) {
			/*
			 *  If the ELCR indicates a level-sensitive interrupt, we
			 *  copy that information over to the MP table in the
			 *  irqflag field (level sensitive, active high polarity).
			 */
			if (ELCR_trigger(i))
				intsrc.mpc_irqflag = 13;
			else
				intsrc.mpc_irqflag = 0;
		}

		intsrc.mpc_srcbusirq = i;
		intsrc.mpc_dstirq = i ? i : 2;		/* IRQ0 to INTIN2 */
		MP_intsrc_info(&intsrc);
	}

	intsrc.mpc_irqtype = mp_ExtINT;
	intsrc.mpc_srcbusirq = 0;
	intsrc.mpc_dstirq = 0;				/* 8259A to INTIN0 */
	MP_intsrc_info(&intsrc);
}

static inline void __init construct_default_ISA_mptable(int mpc_default_type)
{
	struct mpc_config_processor processor;
	struct mpc_config_bus bus;
	struct mpc_config_ioapic ioapic;
	struct mpc_config_lintsrc lintsrc;
	int linttypes[2] = { mp_ExtINT, mp_NMI };
	int i;

	/*
	 * local APIC has default address
	 */
	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;

	/*
	 * 2 CPUs, numbered 0 & 1.
	 */
	processor.mpc_type = MP_PROCESSOR;
	/* Either an integrated APIC or a discrete 82489DX. */
	processor.mpc_apicver = mpc_default_type > 4 ? 0x10 : 0x01;
	processor.mpc_cpuflag = CPU_ENABLED;
	processor.mpc_cpufeature = (boot_cpu_data.x86 << 8) |
				   (boot_cpu_data.x86_model << 4) |
				   boot_cpu_data.x86_mask;
	processor.mpc_featureflag = boot_cpu_data.x86_capability[0];
	processor.mpc_reserved[0] = 0;
	processor.mpc_reserved[1] = 0;
	for (i = 0; i < 2; i++) {
		processor.mpc_apicid = i;
		MP_processor_info(&processor);
	}

	bus.mpc_type = MP_BUS;
	bus.mpc_busid = 0;
	switch (mpc_default_type) {
		default:
			printk("???\nUnknown standard configuration %d\n",
				mpc_default_type);
			/* fall through */
		case 1:
		case 5:
			memcpy(bus.mpc_bustype, "ISA   ", 6);
			break;
		case 2:
		case 6:
		case 3:
			memcpy(bus.mpc_bustype, "EISA  ", 6);
			break;
		case 4:
		case 7:
			memcpy(bus.mpc_bustype, "MCA   ", 6);
	}
	MP_bus_info(&bus);
	if (mpc_default_type > 4) {
		bus.mpc_busid = 1;
		memcpy(bus.mpc_bustype, "PCI   ", 6);
		MP_bus_info(&bus);
	}

	ioapic.mpc_type = MP_IOAPIC;
	ioapic.mpc_apicid = 2;
	ioapic.mpc_apicver = mpc_default_type > 4 ? 0x10 : 0x01;
	ioapic.mpc_flags = MPC_APIC_USABLE;
	ioapic.mpc_apicaddr = 0xFEC00000;
	MP_ioapic_info(&ioapic);

	/*
	 * We set up most of the low 16 IO-APIC pins according to MPS rules.
	 */
	construct_default_ioirq_mptable(mpc_default_type);

	lintsrc.mpc_type = MP_LINTSRC;
	lintsrc.mpc_irqflag = 0;		/* conforming */
	lintsrc.mpc_srcbusid = 0;
	lintsrc.mpc_srcbusirq = 0;
	lintsrc.mpc_destapic = MP_APIC_ALL;
	for (i = 0; i < 2; i++) {
		lintsrc.mpc_irqtype = linttypes[i];
		lintsrc.mpc_destapiclint = i;
		MP_lintsrc_info(&lintsrc);
	}
}

static struct intel_mp_floating *mpf_found;

/*
 * Scan the memory blocks for an SMP configuration block.
 */
void __init get_smp_config (void)
{
	struct intel_mp_floating *mpf = mpf_found;
	printk("Intel MultiProcessor Specification v1.%d\n", mpf->mpf_specification);
	if (mpf->mpf_feature2 & (1<<7)) {
		printk("    IMCR and PIC compatibility mode.\n");
		pic_mode = 1;
	} else {
		printk("    Virtual Wire compatibility mode.\n");
		pic_mode = 0;
	}

	/*
	 * Now see if we need to read further.
	 */
	if (mpf->mpf_feature1 != 0) {

		printk("Default MP configuration #%d\n", mpf->mpf_feature1);
		construct_default_ISA_mptable(mpf->mpf_feature1);

	} else if (mpf->mpf_physptr) {
		/*
		 * Read the physical hardware table.  Anything here will
		 * override the defaults.
		 */
		if (!smp_read_mpc(__va(mpf->mpf_physptr))) {
			smp_found_config = 0;
			printk(KERN_ERR "BIOS bug, MP table errors detected!...\n");
			printk(KERN_ERR "... disabling SMP support. (tell your hw vendor)\n");
			return;
		}
		/*
		 * If there are no explicit MP IRQ entries, then we are
		 * broken.  We set up most of the low 16 IO-APIC pins to
		 * ISA defaults and hope it will work.
		 */
		if (!mp_irq_entries) {
			struct mpc_config_bus bus;

			printk("BIOS bug, no explicit IRQ entries, using default mptable. (tell your hw vendor)\n");

			bus.mpc_type = MP_BUS;
			bus.mpc_busid = 0;
			memcpy(bus.mpc_bustype, "ISA   ", 6);
			MP_bus_info(&bus);

			construct_default_ioirq_mptable(0);
		}

	} else
		BUG();

	printk("Processors: %d\n", num_processors);
	/*
	 * Only use the first configuration found.
	 */
}

static int __init smp_scan_config (unsigned long base, unsigned long length)
{
	unsigned int *bp = phys_to_virt(base);
	struct intel_mp_floating *mpf;

	printk("Scan SMP from %p for %ld bytes.\n", bp,length);
	if (sizeof(*mpf) != 16)
		printk("Error: MPF size\n");

	while (length > 0) {
		mpf = (struct intel_mp_floating *)bp;
		if ((*bp == SMP_MAGIC_IDENT) &&
			(mpf->mpf_length == 1) &&
			!mpf_checksum((unsigned char *)bp, 16) &&
			((mpf->mpf_specification == 1)
				|| (mpf->mpf_specification == 4)) ) {

			smp_found_config = 1;
			printk(KERN_INFO "found SMP MP-table at %016lx\n",
						virt_to_phys(mpf));
			reserve_bootmem_generic(virt_to_phys(mpf), PAGE_SIZE); 
			if (mpf->mpf_physptr)
				reserve_bootmem_generic(mpf->mpf_physptr, PAGE_SIZE); 
			mpf_found = mpf;
			return 1;
		}
		bp += 4;
		length -= 16;
	}
	return 0;
}

void __init find_intel_smp (void)
{
	unsigned long address;

	/*
	 * FIXME: Linux assumes you have 640K of base ram..
	 * this continues the error...
	 *
	 * 1) Scan the bottom 1K for a signature
	 * 2) Scan the top 1K of base RAM
	 * 3) Scan the 64K of bios
	 */
	if (smp_scan_config(0x0,0x400) ||
		smp_scan_config(639*0x400,0x400) ||
			smp_scan_config(0xF0000,0x10000))
		return;
		printk("ok\n");
		
	/*
	 * If it is an SMP machine we should know now, unless the
	 * configuration is in an EISA/MCA bus machine with an
	 * extended bios data area.
	 *
	 * there is a real-mode segmented pointer pointing to the
	 * 4K EBDA area at 0x40E, calculate and scan it here.
	 *
	 * NOTE! There are Linux loaders that will corrupt the EBDA
	 * area, and as such this kind of SMP config may be less
	 * trustworthy, simply because the SMP table may have been
	 * stomped on during early boot. These loaders are buggy and
	 * should be fixed.
	 *
	 * MP1.4 SPEC states to only scan first 1K of 4K EBDA.
	 */

	address = *(unsigned short *)phys_to_virt(0x40E);
	address <<= 4;
	smp_scan_config(address, 0x400);
	if (smp_found_config)
		printk(KERN_WARNING "WARNING: MP table in the EBDA can be UNSAFE, contact [e-mail] if you experience SMP problems!\n");
}

/*
 * - Intel MP Configuration Table
 */
void __init find_smp_config (void)
{
#ifdef CONFIG_X86_LOCAL_APIC
	find_intel_smp();
#endif
}