This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / arch / x86_64 / kernel / mpparse-xen.c
diff --git a/arch/x86_64/kernel/mpparse-xen.c b/arch/x86_64/kernel/mpparse-xen.c
new file mode 100644 (file)
index 0000000..a43ca1e
--- /dev/null
@@ -0,0 +1,1012 @@
+/*
+ *     Intel Multiprocessor Specification 1.1 and 1.4
+ *     compliant MP-table parsing routines.
+ *
+ *     (c) 1995 Alan Cox, Building #3 <alan@redhat.com>
+ *     (c) 1998, 1999, 2000 Ingo Molnar <mingo@redhat.com>
+ *
+ *     Fixes
+ *             Erich Boleyn    :       MP v1.4 and additional changes.
+ *             Alan Cox        :       Added EBDA scanning
+ *             Ingo Molnar     :       various cleanups and rewrites
+ *             Maciej W. Rozycki:      Bits for default MP configurations
+ *             Paul Diefenbaugh:       Added full ACPI support
+ */
+
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/config.h>
+#include <linux/bootmem.h>
+#include <linux/smp_lock.h>
+#include <linux/kernel_stat.h>
+#include <linux/mc146818rtc.h>
+#include <linux/acpi.h>
+#include <linux/module.h>
+
+#include <asm/smp.h>
+#include <asm/mtrr.h>
+#include <asm/mpspec.h>
+#include <asm/pgalloc.h>
+#include <asm/io_apic.h>
+#include <asm/proto.h>
+#include <asm/acpi.h>
+
+/* Have we found an MP table */
+int smp_found_config;
+unsigned int __initdata maxcpus = NR_CPUS;
+
+int acpi_found_madt;
+
+/*
+ * Various Linux-internal data structures created from the
+ * MP-table.
+ */
+unsigned char apic_version [MAX_APICS];
+unsigned char mp_bus_id_to_type [MAX_MP_BUSSES] = { [0 ... MAX_MP_BUSSES-1] = -1 };
+int mp_bus_id_to_pci_bus [MAX_MP_BUSSES] = { [0 ... MAX_MP_BUSSES-1] = -1 };
+
+static int mp_current_pci_id = 0;
+/* I/O APIC entries */
+struct mpc_config_ioapic mp_ioapics[MAX_IO_APICS];
+
+/* # of MP IRQ source entries */
+struct mpc_config_intsrc mp_irqs[MAX_IRQ_SOURCES];
+
+/* MP IRQ source entries */
+int mp_irq_entries;
+
+int nr_ioapics;
+int pic_mode;
+unsigned long mp_lapic_addr = 0;
+
+
+
+/* Processor that is doing the boot up */
+unsigned int boot_cpu_id = -1U;
+/* Internal processor count */
+unsigned int num_processors __initdata = 0;
+
+unsigned disabled_cpus __initdata;
+
+/* Bitmask of physically existing CPUs */
+physid_mask_t phys_cpu_present_map = PHYSID_MASK_NONE;
+
+/* ACPI MADT entry parsing functions */
+#ifdef CONFIG_ACPI
+extern struct acpi_boot_flags acpi_boot;
+#ifdef CONFIG_X86_LOCAL_APIC
+extern int acpi_parse_lapic (acpi_table_entry_header *header);
+extern int acpi_parse_lapic_addr_ovr (acpi_table_entry_header *header);
+extern int acpi_parse_lapic_nmi (acpi_table_entry_header *header);
+#endif /*CONFIG_X86_LOCAL_APIC*/
+#ifdef CONFIG_X86_IO_APIC
+extern int acpi_parse_ioapic (acpi_table_entry_header *header);
+#endif /*CONFIG_X86_IO_APIC*/
+#endif /*CONFIG_ACPI*/
+
+u8 bios_cpu_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID };
+
+
+/*
+ * Intel MP BIOS table parsing routines:
+ */
+
+/*
+ * Checksum an MP configuration block.
+ */
+
+static int __init mpf_checksum(unsigned char *mp, int len)
+{
+       int sum = 0;
+
+       while (len--)
+               sum += *mp++;
+
+       return sum & 0xFF;
+}
+
+#ifndef CONFIG_XEN
+static void __cpuinit MP_processor_info (struct mpc_config_processor *m)
+{
+       int cpu;
+       unsigned char ver;
+       cpumask_t tmp_map;
+
+       if (!(m->mpc_cpuflag & CPU_ENABLED)) {
+               disabled_cpus++;
+               return;
+       }
+
+       printk(KERN_INFO "Processor #%d %d:%d APIC version %d\n",
+               m->mpc_apicid,
+              (m->mpc_cpufeature & CPU_FAMILY_MASK)>>8,
+              (m->mpc_cpufeature & CPU_MODEL_MASK)>>4,
+               m->mpc_apicver);
+
+       if (m->mpc_cpuflag & CPU_BOOTPROCESSOR) {
+               Dprintk("    Bootup CPU\n");
+               boot_cpu_id = m->mpc_apicid;
+       }
+       if (num_processors >= NR_CPUS) {
+               printk(KERN_WARNING "WARNING: NR_CPUS limit of %i reached."
+                       " Processor ignored.\n", NR_CPUS);
+               return;
+       }
+
+       num_processors++;
+       cpus_complement(tmp_map, cpu_present_map);
+       cpu = first_cpu(tmp_map);
+
+#if MAX_APICS < 255    
+       if ((int)m->mpc_apicid > MAX_APICS) {
+               printk(KERN_ERR "Processor #%d INVALID. (Max ID: %d).\n",
+                       m->mpc_apicid, MAX_APICS);
+               return;
+       }
+#endif
+       ver = m->mpc_apicver;
+
+       physid_set(m->mpc_apicid, phys_cpu_present_map);
+       /*
+        * Validate version
+        */
+       if (ver == 0x0) {
+               printk(KERN_ERR "BIOS bug, APIC version is 0 for CPU#%d! fixing up to 0x10. (tell your hw vendor)\n", m->mpc_apicid);
+               ver = 0x10;
+       }
+       apic_version[m->mpc_apicid] = ver;
+       if (m->mpc_cpuflag & CPU_BOOTPROCESSOR) {
+               /*
+                * bios_cpu_apicid is required to have processors listed
+                * in same order as logical cpu numbers. Hence the first
+                * entry is BSP, and so on.
+                */
+               cpu = 0;
+       }
+       bios_cpu_apicid[cpu] = m->mpc_apicid;
+       x86_cpu_to_apicid[cpu] = m->mpc_apicid;
+
+       cpu_set(cpu, cpu_possible_map);
+       cpu_set(cpu, cpu_present_map);
+}
+#else
+void __init MP_processor_info (struct mpc_config_processor *m)
+{
+       num_processors++;
+}
+#endif /* CONFIG_XEN */
+
+static void __init MP_bus_info (struct mpc_config_bus *m)
+{
+       char str[7];
+
+       memcpy(str, m->mpc_bustype, 6);
+       str[6] = 0;
+       Dprintk("Bus #%d is %s\n", m->mpc_busid, str);
+
+       if (strncmp(str, "ISA", 3) == 0) {
+               mp_bus_id_to_type[m->mpc_busid] = MP_BUS_ISA;
+       } else if (strncmp(str, "EISA", 4) == 0) {
+               mp_bus_id_to_type[m->mpc_busid] = MP_BUS_EISA;
+       } else if (strncmp(str, "PCI", 3) == 0) {
+               mp_bus_id_to_type[m->mpc_busid] = MP_BUS_PCI;
+               mp_bus_id_to_pci_bus[m->mpc_busid] = mp_current_pci_id;
+               mp_current_pci_id++;
+       } else if (strncmp(str, "MCA", 3) == 0) {
+               mp_bus_id_to_type[m->mpc_busid] = MP_BUS_MCA;
+       } else {
+               printk(KERN_ERR "Unknown bustype %s\n", str);
+       }
+}
+
+static void __init MP_ioapic_info (struct mpc_config_ioapic *m)
+{
+       if (!(m->mpc_flags & MPC_APIC_USABLE))
+               return;
+
+       printk("I/O APIC #%d Version %d at 0x%X.\n",
+               m->mpc_apicid, m->mpc_apicver, m->mpc_apicaddr);
+       if (nr_ioapics >= MAX_IO_APICS) {
+               printk(KERN_ERR "Max # of I/O APICs (%d) exceeded (found %d).\n",
+                       MAX_IO_APICS, nr_ioapics);
+               panic("Recompile kernel with bigger MAX_IO_APICS!.\n");
+       }
+       if (!m->mpc_apicaddr) {
+               printk(KERN_ERR "WARNING: bogus zero I/O APIC address"
+                       " found in MP table, skipping!\n");
+               return;
+       }
+       mp_ioapics[nr_ioapics] = *m;
+       nr_ioapics++;
+}
+
+static void __init MP_intsrc_info (struct mpc_config_intsrc *m)
+{
+       mp_irqs [mp_irq_entries] = *m;
+       Dprintk("Int: type %d, pol %d, trig %d, bus %d,"
+               " IRQ %02x, APIC ID %x, APIC INT %02x\n",
+                       m->mpc_irqtype, m->mpc_irqflag & 3,
+                       (m->mpc_irqflag >> 2) & 3, m->mpc_srcbus,
+                       m->mpc_srcbusirq, m->mpc_dstapic, m->mpc_dstirq);
+       if (++mp_irq_entries >= MAX_IRQ_SOURCES)
+               panic("Max # of irq sources exceeded!!\n");
+}
+
+static void __init MP_lintsrc_info (struct mpc_config_lintsrc *m)
+{
+       Dprintk("Lint: type %d, pol %d, trig %d, bus %d,"
+               " IRQ %02x, APIC ID %x, APIC LINT %02x\n",
+                       m->mpc_irqtype, m->mpc_irqflag & 3,
+                       (m->mpc_irqflag >> 2) &3, m->mpc_srcbusid,
+                       m->mpc_srcbusirq, m->mpc_destapic, m->mpc_destapiclint);
+       /*
+        * Well it seems all SMP boards in existence
+        * use ExtINT/LVT1 == LINT0 and
+        * NMI/LVT2 == LINT1 - the following check
+        * will show us if this assumptions is false.
+        * Until then we do not have to add baggage.
+        */
+       if ((m->mpc_irqtype == mp_ExtINT) &&
+               (m->mpc_destapiclint != 0))
+                       BUG();
+       if ((m->mpc_irqtype == mp_NMI) &&
+               (m->mpc_destapiclint != 1))
+                       BUG();
+}
+
+/*
+ * Read/parse the MPC
+ */
+
+static int __init smp_read_mpc(struct mp_config_table *mpc)
+{
+       char str[16];
+       int count=sizeof(*mpc);
+       unsigned char *mpt=((unsigned char *)mpc)+count;
+
+       if (memcmp(mpc->mpc_signature,MPC_SIGNATURE,4)) {
+               printk("SMP mptable: bad signature [%c%c%c%c]!\n",
+                       mpc->mpc_signature[0],
+                       mpc->mpc_signature[1],
+                       mpc->mpc_signature[2],
+                       mpc->mpc_signature[3]);
+               return 0;
+       }
+       if (mpf_checksum((unsigned char *)mpc,mpc->mpc_length)) {
+               printk("SMP mptable: checksum error!\n");
+               return 0;
+       }
+       if (mpc->mpc_spec!=0x01 && mpc->mpc_spec!=0x04) {
+               printk(KERN_ERR "SMP mptable: bad table version (%d)!!\n",
+                       mpc->mpc_spec);
+               return 0;
+       }
+       if (!mpc->mpc_lapic) {
+               printk(KERN_ERR "SMP mptable: null local APIC address!\n");
+               return 0;
+       }
+       memcpy(str,mpc->mpc_oem,8);
+       str[8]=0;
+       printk(KERN_INFO "OEM ID: %s ",str);
+
+       memcpy(str,mpc->mpc_productid,12);
+       str[12]=0;
+       printk("Product ID: %s ",str);
+
+       printk("APIC at: 0x%X\n",mpc->mpc_lapic);
+
+       /* save the local APIC address, it might be non-default */
+       if (!acpi_lapic)
+       mp_lapic_addr = mpc->mpc_lapic;
+
+       /*
+        *      Now process the configuration blocks.
+        */
+       while (count < mpc->mpc_length) {
+               switch(*mpt) {
+                       case MP_PROCESSOR:
+                       {
+                               struct mpc_config_processor *m=
+                                       (struct mpc_config_processor *)mpt;
+                               if (!acpi_lapic)
+                               MP_processor_info(m);
+                               mpt += sizeof(*m);
+                               count += sizeof(*m);
+                               break;
+                       }
+                       case MP_BUS:
+                       {
+                               struct mpc_config_bus *m=
+                                       (struct mpc_config_bus *)mpt;
+                               MP_bus_info(m);
+                               mpt += sizeof(*m);
+                               count += sizeof(*m);
+                               break;
+                       }
+                       case MP_IOAPIC:
+                       {
+                               struct mpc_config_ioapic *m=
+                                       (struct mpc_config_ioapic *)mpt;
+                               MP_ioapic_info(m);
+                               mpt+=sizeof(*m);
+                               count+=sizeof(*m);
+                               break;
+                       }
+                       case MP_INTSRC:
+                       {
+                               struct mpc_config_intsrc *m=
+                                       (struct mpc_config_intsrc *)mpt;
+
+                               MP_intsrc_info(m);
+                               mpt+=sizeof(*m);
+                               count+=sizeof(*m);
+                               break;
+                       }
+                       case MP_LINTSRC:
+                       {
+                               struct mpc_config_lintsrc *m=
+                                       (struct mpc_config_lintsrc *)mpt;
+                               MP_lintsrc_info(m);
+                               mpt+=sizeof(*m);
+                               count+=sizeof(*m);
+                               break;
+                       }
+               }
+       }
+       clustered_apic_check();
+       if (!num_processors)
+               printk(KERN_ERR "SMP mptable: no processors registered!\n");
+       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(KERN_INFO "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(KERN_ERR "ELCR contains invalid data... not using ELCR\n");
+               else {
+                       printk(KERN_INFO "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(KERN_ERR "???\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;
+
+       /*
+        * ACPI supports both logical (e.g. Hyper-Threading) and physical 
+        * processors, where MPS only supports physical.
+        */
+       if (acpi_lapic && acpi_ioapic) {
+               printk(KERN_INFO "Using ACPI (MADT) for SMP configuration information\n");
+               return;
+       }
+       else if (acpi_lapic)
+               printk(KERN_INFO "Using ACPI for processor (LAPIC) configuration information\n");
+
+       printk("Intel MultiProcessor Specification v1.%d\n", mpf->mpf_specification);
+       if (mpf->mpf_feature2 & (1<<7)) {
+               printk(KERN_INFO "    IMCR and PIC compatibility mode.\n");
+               pic_mode = 1;
+       } else {
+               printk(KERN_INFO "    Virtual Wire compatibility mode.\n");
+               pic_mode = 0;
+       }
+
+       /*
+        * Now see if we need to read further.
+        */
+       if (mpf->mpf_feature1 != 0) {
+
+               printk(KERN_INFO "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(isa_bus_to_virt(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(KERN_ERR "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(KERN_INFO "Processors: %d\n", num_processors);
+       /*
+        * Only use the first configuration found.
+        */
+}
+
+static int __init smp_scan_config (unsigned long base, unsigned long length)
+{
+       extern void __bad_mpf_size(void); 
+       unsigned int *bp = isa_bus_to_virt(base);
+       struct intel_mp_floating *mpf;
+
+       Dprintk("Scan SMP from %p for %ld bytes.\n", bp,length);
+       if (sizeof(*mpf) != 16)
+               __bad_mpf_size();
+
+       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;
+                       mpf_found = mpf;
+                       return 1;
+               }
+               bp += 4;
+               length -= 16;
+       }
+       return 0;
+}
+
+void __init find_intel_smp (void)
+{
+       unsigned int 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;
+       /*
+        * 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.
+        */
+
+       address = *(unsigned short *)phys_to_virt(0x40E);
+       address <<= 4;
+       if (smp_scan_config(address, 0x1000))
+               return;
+
+       /* If we have come this far, we did not find an MP table  */
+        printk(KERN_INFO "No mptable found.\n");
+}
+
+/*
+ * - Intel MP Configuration Table
+ */
+void __init find_smp_config (void)
+{
+#ifdef CONFIG_X86_LOCAL_APIC
+       find_intel_smp();
+#endif
+}
+
+
+/* --------------------------------------------------------------------------
+                            ACPI-based MP Configuration
+   -------------------------------------------------------------------------- */
+
+#ifdef CONFIG_ACPI
+
+void __init mp_register_lapic_address (
+       u64                     address)
+{
+#ifndef CONFIG_XEN
+       mp_lapic_addr = (unsigned long) address;
+
+       set_fixmap_nocache(FIX_APIC_BASE, mp_lapic_addr);
+
+       if (boot_cpu_id == -1U)
+               boot_cpu_id = GET_APIC_ID(apic_read(APIC_ID));
+
+       Dprintk("Boot CPU = %d\n", boot_cpu_physical_apicid);
+#endif
+}
+
+
+void __cpuinit mp_register_lapic (
+       u8                      id, 
+       u8                      enabled)
+{
+       struct mpc_config_processor processor;
+       int                     boot_cpu = 0;
+       
+       if (id >= MAX_APICS) {
+               printk(KERN_WARNING "Processor #%d invalid (max %d)\n",
+                       id, MAX_APICS);
+               return;
+       }
+
+       if (id == boot_cpu_physical_apicid)
+               boot_cpu = 1;
+
+#ifndef CONFIG_XEN
+       processor.mpc_type = MP_PROCESSOR;
+       processor.mpc_apicid = id;
+       processor.mpc_apicver = GET_APIC_VERSION(apic_read(APIC_LVR));
+       processor.mpc_cpuflag = (enabled ? CPU_ENABLED : 0);
+       processor.mpc_cpuflag |= (boot_cpu ? CPU_BOOTPROCESSOR : 0);
+       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;
+#endif
+
+       MP_processor_info(&processor);
+}
+
+#ifdef CONFIG_X86_IO_APIC
+
+#define MP_ISA_BUS             0
+#define MP_MAX_IOAPIC_PIN      127
+
+static struct mp_ioapic_routing {
+       int                     apic_id;
+       int                     gsi_start;
+       int                     gsi_end;
+       u32                     pin_programmed[4];
+} mp_ioapic_routing[MAX_IO_APICS];
+
+
+static int mp_find_ioapic (
+       int                     gsi)
+{
+       int                     i = 0;
+
+       /* Find the IOAPIC that manages this GSI. */
+       for (i = 0; i < nr_ioapics; i++) {
+               if ((gsi >= mp_ioapic_routing[i].gsi_start)
+                       && (gsi <= mp_ioapic_routing[i].gsi_end))
+                       return i;
+       }
+
+       printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
+
+       return -1;
+}
+       
+
+void __init mp_register_ioapic (
+       u8                      id, 
+       u32                     address,
+       u32                     gsi_base)
+{
+       int                     idx = 0;
+
+       if (nr_ioapics >= MAX_IO_APICS) {
+               printk(KERN_ERR "ERROR: Max # of I/O APICs (%d) exceeded "
+                       "(found %d)\n", MAX_IO_APICS, nr_ioapics);
+               panic("Recompile kernel with bigger MAX_IO_APICS!\n");
+       }
+       if (!address) {
+               printk(KERN_ERR "WARNING: Bogus (zero) I/O APIC address"
+                       " found in MADT table, skipping!\n");
+               return;
+       }
+
+       idx = nr_ioapics++;
+
+       mp_ioapics[idx].mpc_type = MP_IOAPIC;
+       mp_ioapics[idx].mpc_flags = MPC_APIC_USABLE;
+       mp_ioapics[idx].mpc_apicaddr = address;
+
+#ifndef CONFIG_XEN
+       set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
+#endif
+       mp_ioapics[idx].mpc_apicid = id;
+       mp_ioapics[idx].mpc_apicver = io_apic_get_version(idx);
+       
+       /* 
+        * Build basic IRQ lookup table to facilitate gsi->io_apic lookups
+        * and to prevent reprogramming of IOAPIC pins (PCI IRQs).
+        */
+       mp_ioapic_routing[idx].apic_id = mp_ioapics[idx].mpc_apicid;
+       mp_ioapic_routing[idx].gsi_start = gsi_base;
+       mp_ioapic_routing[idx].gsi_end = gsi_base + 
+               io_apic_get_redir_entries(idx);
+
+       printk(KERN_INFO "IOAPIC[%d]: apic_id %d, version %d, address 0x%x, "
+               "GSI %d-%d\n", idx, mp_ioapics[idx].mpc_apicid, 
+               mp_ioapics[idx].mpc_apicver, mp_ioapics[idx].mpc_apicaddr,
+               mp_ioapic_routing[idx].gsi_start,
+               mp_ioapic_routing[idx].gsi_end);
+
+       return;
+}
+
+
+void __init mp_override_legacy_irq (
+       u8                      bus_irq,
+       u8                      polarity, 
+       u8                      trigger, 
+       u32                     gsi)
+{
+       struct mpc_config_intsrc intsrc;
+       int                     ioapic = -1;
+       int                     pin = -1;
+
+       /* 
+        * Convert 'gsi' to 'ioapic.pin'.
+        */
+       ioapic = mp_find_ioapic(gsi);
+       if (ioapic < 0)
+               return;
+       pin = gsi - mp_ioapic_routing[ioapic].gsi_start;
+
+       /*
+        * TBD: This check is for faulty timer entries, where the override
+        *      erroneously sets the trigger to level, resulting in a HUGE 
+        *      increase of timer interrupts!
+        */
+       if ((bus_irq == 0) && (trigger == 3))
+               trigger = 1;
+
+       intsrc.mpc_type = MP_INTSRC;
+       intsrc.mpc_irqtype = mp_INT;
+       intsrc.mpc_irqflag = (trigger << 2) | polarity;
+       intsrc.mpc_srcbus = MP_ISA_BUS;
+       intsrc.mpc_srcbusirq = bus_irq;                                /* IRQ */
+       intsrc.mpc_dstapic = mp_ioapics[ioapic].mpc_apicid;        /* APIC ID */
+       intsrc.mpc_dstirq = pin;                                    /* INTIN# */
+
+       Dprintk("Int: type %d, pol %d, trig %d, bus %d, irq %d, %d-%d\n", 
+               intsrc.mpc_irqtype, intsrc.mpc_irqflag & 3, 
+               (intsrc.mpc_irqflag >> 2) & 3, intsrc.mpc_srcbus, 
+               intsrc.mpc_srcbusirq, intsrc.mpc_dstapic, intsrc.mpc_dstirq);
+
+       mp_irqs[mp_irq_entries] = intsrc;
+       if (++mp_irq_entries == MAX_IRQ_SOURCES)
+               panic("Max # of irq sources exceeded!\n");
+
+       return;
+}
+
+
+void __init mp_config_acpi_legacy_irqs (void)
+{
+       struct mpc_config_intsrc intsrc;
+       int                     i = 0;
+       int                     ioapic = -1;
+
+       /* 
+        * Fabricate the legacy ISA bus (bus #31).
+        */
+       mp_bus_id_to_type[MP_ISA_BUS] = MP_BUS_ISA;
+       Dprintk("Bus #%d is ISA\n", MP_ISA_BUS);
+
+       /* 
+        * Locate the IOAPIC that manages the ISA IRQs (0-15). 
+        */
+       ioapic = mp_find_ioapic(0);
+       if (ioapic < 0)
+               return;
+
+       intsrc.mpc_type = MP_INTSRC;
+       intsrc.mpc_irqflag = 0;                                 /* Conforming */
+       intsrc.mpc_srcbus = MP_ISA_BUS;
+       intsrc.mpc_dstapic = mp_ioapics[ioapic].mpc_apicid;
+
+       /* 
+        * Use the default configuration for the IRQs 0-15.  Unless
+        * overridden by (MADT) interrupt source override entries.
+        */
+       for (i = 0; i < 16; i++) {
+               int idx;
+
+               for (idx = 0; idx < mp_irq_entries; idx++) {
+                       struct mpc_config_intsrc *irq = mp_irqs + idx;
+
+                       /* Do we already have a mapping for this ISA IRQ? */
+                       if (irq->mpc_srcbus == MP_ISA_BUS && irq->mpc_srcbusirq == i)
+                               break;
+
+                       /* Do we already have a mapping for this IOAPIC pin */
+                       if ((irq->mpc_dstapic == intsrc.mpc_dstapic) &&
+                               (irq->mpc_dstirq == i))
+                               break;
+               }
+
+               if (idx != mp_irq_entries) {
+                       printk(KERN_DEBUG "ACPI: IRQ%d used by override.\n", i);
+                       continue;                       /* IRQ already used */
+               }
+
+               intsrc.mpc_irqtype = mp_INT;
+               intsrc.mpc_srcbusirq = i;                  /* Identity mapped */
+               intsrc.mpc_dstirq = i;
+
+               Dprintk("Int: type %d, pol %d, trig %d, bus %d, irq %d, "
+                       "%d-%d\n", intsrc.mpc_irqtype, intsrc.mpc_irqflag & 3, 
+                       (intsrc.mpc_irqflag >> 2) & 3, intsrc.mpc_srcbus, 
+                       intsrc.mpc_srcbusirq, intsrc.mpc_dstapic, 
+                       intsrc.mpc_dstirq);
+
+               mp_irqs[mp_irq_entries] = intsrc;
+               if (++mp_irq_entries == MAX_IRQ_SOURCES)
+                       panic("Max # of irq sources exceeded!\n");
+       }
+
+       return;
+}
+
+#define MAX_GSI_NUM    4096
+
+int mp_register_gsi(u32 gsi, int triggering, int polarity)
+{
+       int                     ioapic = -1;
+       int                     ioapic_pin = 0;
+       int                     idx, bit = 0;
+       static int              pci_irq = 16;
+       /*
+        * Mapping between Global System Interrupts, which
+        * represent all possible interrupts, to the IRQs
+        * assigned to actual devices.
+        */
+       static int              gsi_to_irq[MAX_GSI_NUM];
+
+       if (acpi_irq_model != ACPI_IRQ_MODEL_IOAPIC)
+               return gsi;
+
+       /* Don't set up the ACPI SCI because it's already set up */
+       if (acpi_fadt.sci_int == gsi)
+               return gsi;
+
+       ioapic = mp_find_ioapic(gsi);
+       if (ioapic < 0) {
+               printk(KERN_WARNING "No IOAPIC for GSI %u\n", gsi);
+               return gsi;
+       }
+
+       ioapic_pin = gsi - mp_ioapic_routing[ioapic].gsi_start;
+
+       /* 
+        * Avoid pin reprogramming.  PRTs typically include entries  
+        * with redundant pin->gsi mappings (but unique PCI devices);
+        * we only program the IOAPIC on the first.
+        */
+       bit = ioapic_pin % 32;
+       idx = (ioapic_pin < 32) ? 0 : (ioapic_pin / 32);
+       if (idx > 3) {
+               printk(KERN_ERR "Invalid reference to IOAPIC pin "
+                       "%d-%d\n", mp_ioapic_routing[ioapic].apic_id, 
+                       ioapic_pin);
+               return gsi;
+       }
+       if ((1<<bit) & mp_ioapic_routing[ioapic].pin_programmed[idx]) {
+               Dprintk(KERN_DEBUG "Pin %d-%d already programmed\n",
+                       mp_ioapic_routing[ioapic].apic_id, ioapic_pin);
+               return gsi_to_irq[gsi];
+       }
+
+       mp_ioapic_routing[ioapic].pin_programmed[idx] |= (1<<bit);
+
+       if (triggering == ACPI_LEVEL_SENSITIVE) {
+               /*
+                * For PCI devices assign IRQs in order, avoiding gaps
+                * due to unused I/O APIC pins.
+                */
+               int irq = gsi;
+               if (gsi < MAX_GSI_NUM) {
+                       /*
+                        * Retain the VIA chipset work-around (gsi > 15), but
+                        * avoid a problem where the 8254 timer (IRQ0) is setup
+                        * via an override (so it's not on pin 0 of the ioapic),
+                        * and at the same time, the pin 0 interrupt is a PCI
+                        * type.  The gsi > 15 test could cause these two pins
+                        * to be shared as IRQ0, and they are not shareable.
+                        * So test for this condition, and if necessary, avoid
+                        * the pin collision.
+                        */
+                       if (gsi > 15 || (gsi == 0 && !timer_uses_ioapic_pin_0))
+                               gsi = pci_irq++;
+                       /*
+                        * Don't assign IRQ used by ACPI SCI
+                        */
+                       if (gsi == acpi_fadt.sci_int)
+                               gsi = pci_irq++;
+                       gsi_to_irq[irq] = gsi;
+               } else {
+                       printk(KERN_ERR "GSI %u is too high\n", gsi);
+                       return gsi;
+               }
+       }
+
+       io_apic_set_pci_routing(ioapic, ioapic_pin, gsi,
+               triggering == ACPI_EDGE_SENSITIVE ? 0 : 1,
+               polarity == ACPI_ACTIVE_HIGH ? 0 : 1);
+       return gsi;
+}
+
+#endif /*CONFIG_X86_IO_APIC*/
+#endif /*CONFIG_ACPI*/