Merge branch 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-apic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
  ACPI, x86: expose some IO-APIC routines when CONFIG_ACPI=n
  x86, apic: Slim down stack usage in early_init_lapic_mapping()
  x86, ioapic: Get rid of needless check and simplify ioapic_setup_resources()
  x86, ioapic: Define IO_APIC_DEFAULT_PHYS_BASE constant
  x86: Fix x86_model test in es7000_apic_is_cluster()
  x86, apic: Move dmar_table_init() out of enable_IR()
  x86, ioapic: Panic on irq-pin binding only if needed
  x86/apic: Enable x2APIC without interrupt remapping under KVM
  x86, apic: Drop redundant bit assignment
  x86, ioapic: Throw BUG instead of NULL dereference
  x86, ioapic: Introduce for_each_irq_pin() helper
  x86: Remove superfluous NULL pointer check in destroy_irq()
  x86/ioapic.c: unify ioapic_retrigger_irq()
  x86/ioapic.c: convert __target_IO_APIC_irq to conventional for() loop
  x86/ioapic.c: clean up replace_pin_at_irq_node logic and comments
  x86/ioapic.c: convert replace_pin_at_irq_node to conventional for() loop
  x86/ioapic.c: simplify add_pin_to_irq_node()
  x86/ioapic.c: convert io_apic_level_ack_pending loop to normal for() loop
  x86/ioapic.c: move lost comment to what seems like appropriate place
  x86/ioapic.c: remove redundant declaration of irq_pin_list
  ...

9 files changed, 269 insertions, 311 deletions

diff --git a/arch/x86/include/asm/apic.h b/arch/x86/include/asm/apic.h
index bb7d47925847..586b7adb8e53 100644
--- a/arch/x86/include/asm/apic.h
+++ b/arch/x86/include/asm/apic.h
@@ -183,6 +183,10 @@ static inline int x2apic_enabled(void)
 }
 
 #define x2apic_supported()      (cpu_has_x2apic)
+static inline void x2apic_force_phys(void)
+{
+        x2apic_phys = 1;
+}
 #else
 static inline void check_x2apic(void)
 {
@@ -194,6 +198,9 @@ static inline int x2apic_enabled(void)
 {
         return 0;
 }
+static inline void x2apic_force_phys(void)
+{
+}
 
 #define x2apic_preenabled 0
 #define x2apic_supported()      0
diff --git a/arch/x86/include/asm/apicdef.h b/arch/x86/include/asm/apicdef.h
index 7ddb36ab933b..7386bfa4f4bc 100644
--- a/arch/x86/include/asm/apicdef.h
+++ b/arch/x86/include/asm/apicdef.h
@@ -8,7 +8,8 @@
  * Ingo Molnar <mingo@redhat.com>, 1999, 2000
  */
 
-#define APIC_DEFAULT_PHYS_BASE  0xfee00000
+#define IO_APIC_DEFAULT_PHYS_BASE       0xfec00000
+#define APIC_DEFAULT_PHYS_BASE          0xfee00000
 
 #define APIC_ID         0x20
 
diff --git a/arch/x86/include/asm/io_apic.h b/arch/x86/include/asm/io_apic.h
index 330ee807f89e..85232d32fcb8 100644
--- a/arch/x86/include/asm/io_apic.h
+++ b/arch/x86/include/asm/io_apic.h
@@ -150,11 +150,10 @@ extern int timer_through_8259;
 #define io_apic_assign_pci_irqs \
         (mp_irq_entries && !skip_ioapic_setup && io_apic_irqs)
 
-#ifdef CONFIG_ACPI
+extern u8 io_apic_unique_id(u8 id);
 extern int io_apic_get_unique_id(int ioapic, int apic_id);
 extern int io_apic_get_version(int ioapic);
 extern int io_apic_get_redir_entries(int ioapic);
-#endif /* CONFIG_ACPI */
 
 struct io_apic_irq_attr;
 extern int io_apic_set_pci_routing(struct device *dev, int irq,
@@ -177,6 +176,16 @@ extern int setup_ioapic_entry(int apic, int irq,
                               int polarity, int vector, int pin);
 extern void ioapic_write_entry(int apic, int pin,
                                struct IO_APIC_route_entry e);
+
+struct mp_ioapic_gsi{
+        int gsi_base;
+        int gsi_end;
+};
+extern struct mp_ioapic_gsi  mp_gsi_routing[];
+int mp_find_ioapic(int gsi);
+int mp_find_ioapic_pin(int ioapic, int gsi);
+void __init mp_register_ioapic(int id, u32 address, u32 gsi_base);
+
 #else  /* !CONFIG_X86_IO_APIC */
 #define io_apic_assign_pci_irqs 0
 static const int timer_through_8259 = 0;
diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
index 6b8ca3a0285d..67e929b89875 100644
--- a/arch/x86/kernel/acpi/boot.c
+++ b/arch/x86/kernel/acpi/boot.c
@@ -833,106 +833,6 @@ static int __init acpi_parse_madt_lapic_entries(void)
 extern int es7000_plat;
 #endif
 
-static struct {
-        int gsi_base;
-        int gsi_end;
-} mp_ioapic_routing[MAX_IO_APICS];
-
-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_base)
-                    && (gsi <= mp_ioapic_routing[i].gsi_end))
-                        return i;
-        }
-
-        printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
-        return -1;
-}
-
-int mp_find_ioapic_pin(int ioapic, int gsi)
-{
-        if (WARN_ON(ioapic == -1))
-                return -1;
-        if (WARN_ON(gsi > mp_ioapic_routing[ioapic].gsi_end))
-                return -1;
-
-        return gsi - mp_ioapic_routing[ioapic].gsi_base;
-}
-
-static u8 __init uniq_ioapic_id(u8 id)
-{
-#ifdef CONFIG_X86_32
-        if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
-            !APIC_XAPIC(apic_version[boot_cpu_physical_apicid]))
-                return io_apic_get_unique_id(nr_ioapics, id);
-        else
-                return id;
-#else
-        int i;
-        DECLARE_BITMAP(used, 256);
-        bitmap_zero(used, 256);
-        for (i = 0; i < nr_ioapics; i++) {
-                struct mpc_ioapic *ia = &mp_ioapics[i];
-                __set_bit(ia->apicid, used);
-        }
-        if (!test_bit(id, used))
-                return id;
-        return find_first_zero_bit(used, 256);
-#endif
-}
-
-static int bad_ioapic(unsigned long address)
-{
-        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 table, skipping!\n");
-                return 1;
-        }
-        return 0;
-}
-
-void __init mp_register_ioapic(int id, u32 address, u32 gsi_base)
-{
-        int idx = 0;
-
-        if (bad_ioapic(address))
-                return;
-
-        idx = nr_ioapics;
-
-        mp_ioapics[idx].type = MP_IOAPIC;
-        mp_ioapics[idx].flags = MPC_APIC_USABLE;
-        mp_ioapics[idx].apicaddr = address;
-
-        set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
-        mp_ioapics[idx].apicid = uniq_ioapic_id(id);
-        mp_ioapics[idx].apicver = io_apic_get_version(idx);
-
-        /*
-         * Build basic GSI lookup table to facilitate gsi->io_apic lookups
-         * and to prevent reprogramming of IOAPIC pins (PCI GSIs).
-         */
-        mp_ioapic_routing[idx].gsi_base = 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].apicid,
-               mp_ioapics[idx].apicver, mp_ioapics[idx].apicaddr,
-               mp_ioapic_routing[idx].gsi_base, mp_ioapic_routing[idx].gsi_end);
-
-        nr_ioapics++;
-}
-
 int __init acpi_probe_gsi(void)
 {
         int idx;
@@ -947,7 +847,7 @@ int __init acpi_probe_gsi(void)
 
         max_gsi = 0;
         for (idx = 0; idx < nr_ioapics; idx++) {
-                gsi = mp_ioapic_routing[idx].gsi_end;
+                gsi = mp_gsi_routing[idx].gsi_end;
 
                 if (gsi > max_gsi)
                         max_gsi = gsi;
@@ -1179,9 +1079,8 @@ static int __init acpi_parse_madt_ioapic_entries(void)
          * If MPS is present, it will handle them,
          * otherwise the system will stay in PIC mode
          */
-        if (acpi_disabled || acpi_noirq) {
+        if (acpi_disabled || acpi_noirq)
                 return -ENODEV;
-        }
 
         if (!cpu_has_apic)
                 return -ENODEV;
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c
index 0a1c2830ec66..159740decc41 100644
--- a/arch/x86/kernel/apic/apic.c
+++ b/arch/x86/kernel/apic/apic.c
@@ -49,6 +49,7 @@
 #include <asm/mtrr.h>
 #include <asm/smp.h>
 #include <asm/mce.h>
+#include <asm/kvm_para.h>
 
 unsigned int num_processors;
 
@@ -1361,52 +1362,80 @@ void enable_x2apic(void)
 }
 #endif /* CONFIG_X86_X2APIC */
 
-void __init enable_IR_x2apic(void)
+int __init enable_IR(void)
 {
 #ifdef CONFIG_INTR_REMAP
-        int ret;
-        unsigned long flags;
-        struct IO_APIC_route_entry **ioapic_entries = NULL;
-
-        ret = dmar_table_init();
-        if (ret) {
-                pr_debug("dmar_table_init() failed with %d:\n", ret);
-                goto ir_failed;
-        }
-
         if (!intr_remapping_supported()) {
                 pr_debug("intr-remapping not supported\n");
-                goto ir_failed;
+                return 0;
         }
 
-
         if (!x2apic_preenabled && skip_ioapic_setup) {
                 pr_info("Skipped enabling intr-remap because of skipping "
                         "io-apic setup\n");
-                return;
+                return 0;
         }
 
+        if (enable_intr_remapping(x2apic_supported()))
+                return 0;
+
+        pr_info("Enabled Interrupt-remapping\n");
+
+        return 1;
+
+#endif
+        return 0;
+}
+
+void __init enable_IR_x2apic(void)
+{
+        unsigned long flags;
+        struct IO_APIC_route_entry **ioapic_entries = NULL;
+        int ret, x2apic_enabled = 0;
+        int dmar_table_init_ret = 0;
+
+#ifdef CONFIG_INTR_REMAP
+        dmar_table_init_ret = dmar_table_init();
+        if (dmar_table_init_ret)
+                pr_debug("dmar_table_init() failed with %d:\n",
+                                dmar_table_init_ret);
+#endif
+
         ioapic_entries = alloc_ioapic_entries();
         if (!ioapic_entries) {
-                pr_info("Allocate ioapic_entries failed: %d\n", ret);
-                goto end;
+                pr_err("Allocate ioapic_entries failed\n");
+                goto out;
         }
 
         ret = save_IO_APIC_setup(ioapic_entries);
         if (ret) {
                 pr_info("Saving IO-APIC state failed: %d\n", ret);
-                goto end;
+                goto out;
         }
 
         local_irq_save(flags);
-        mask_IO_APIC_setup(ioapic_entries);
         mask_8259A();
+        mask_IO_APIC_setup(ioapic_entries);
 
-        ret = enable_intr_remapping(x2apic_supported());
-        if (ret)
-                goto end_restore;
+        if (dmar_table_init_ret)
+                ret = 0;
+        else
+                ret = enable_IR();
 
-        pr_info("Enabled Interrupt-remapping\n");
+        if (!ret) {
+                /* IR is required if there is APIC ID > 255 even when running
+                 * under KVM
+                 */
+                if (max_physical_apicid > 255 || !kvm_para_available())
+                        goto nox2apic;
+                /*
+                 * without IR all CPUs can be addressed by IOAPIC/MSI
+                 * only in physical mode
+                 */
+                x2apic_force_phys();
+        }
+
+        x2apic_enabled = 1;
 
         if (x2apic_supported() && !x2apic_mode) {
                 x2apic_mode = 1;
@@ -1414,41 +1443,25 @@ void __init enable_IR_x2apic(void)
                 pr_info("Enabled x2apic\n");
         }
 
-end_restore:
-        if (ret)
-                /*
-                 * IR enabling failed
-                 */
+nox2apic:
+        if (!ret) /* IR enabling failed */
                 restore_IO_APIC_setup(ioapic_entries);
-
         unmask_8259A();
         local_irq_restore(flags);
 
-end:
+out:
         if (ioapic_entries)
                 free_ioapic_entries(ioapic_entries);
 
-        if (!ret)
+        if (x2apic_enabled)
                 return;
 
-ir_failed:
         if (x2apic_preenabled)
-                panic("x2apic enabled by bios. But IR enabling failed");
+                panic("x2apic: enabled by BIOS but kernel init failed.");
         else if (cpu_has_x2apic)
-                pr_info("Not enabling x2apic,Intr-remapping\n");
-#else
-        if (!cpu_has_x2apic)
-                return;
-
-        if (x2apic_preenabled)
-                panic("x2apic enabled prior OS handover,"
-                      " enable CONFIG_X86_X2APIC, CONFIG_INTR_REMAP");
-#endif
-
-        return;
+                pr_info("Not enabling x2apic, Intr-remapping init failed.\n");
 }
 
-
 #ifdef CONFIG_X86_64
 /*
  * Detect and enable local APICs on non-SMP boards.
@@ -1549,8 +1562,6 @@ no_apic:
 #ifdef CONFIG_X86_64
 void __init early_init_lapic_mapping(void)
 {
-        unsigned long phys_addr;
-
         /*
          * If no local APIC can be found then go out
          * : it means there is no mpatable and MADT
@@ -1558,11 +1569,9 @@ void __init early_init_lapic_mapping(void)
         if (!smp_found_config)
                 return;
 
-        phys_addr = mp_lapic_addr;
-
-        set_fixmap_nocache(FIX_APIC_BASE, phys_addr);
+        set_fixmap_nocache(FIX_APIC_BASE, mp_lapic_addr);
         apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
-                    APIC_BASE, phys_addr);
+                    APIC_BASE, mp_lapic_addr);
 
         /*
          * Fetch the APIC ID of the BSP in case we have a
@@ -1651,7 +1660,6 @@ int __init APIC_init_uniprocessor(void)
             APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
                 pr_err("BIOS bug, local APIC 0x%x not detected!...\n",
                         boot_cpu_physical_apicid);
-                clear_cpu_cap(&boot_cpu_data, X86_FEATURE_APIC);
                 return -1;
         }
 #endif
diff --git a/arch/x86/kernel/apic/es7000_32.c b/arch/x86/kernel/apic/es7000_32.c
index 8952a5890281..89174f847b49 100644
--- a/arch/x86/kernel/apic/es7000_32.c
+++ b/arch/x86/kernel/apic/es7000_32.c
@@ -167,7 +167,7 @@ static int es7000_apic_is_cluster(void)
 {
         /* MPENTIUMIII */
         if (boot_cpu_data.x86 == 6 &&
-            (boot_cpu_data.x86_model >= 7 || boot_cpu_data.x86_model <= 11))
+            (boot_cpu_data.x86_model >= 7 && boot_cpu_data.x86_model <= 11))
                 return 1;
 
         return 0;
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c
index d2ed6c5ddc80..3c8f9e75d038 100644
--- a/arch/x86/kernel/apic/io_apic.c
+++ b/arch/x86/kernel/apic/io_apic.c
@@ -66,6 +66,8 @@
 #include <asm/apic.h>
 
 #define __apicdebuginit(type) static type __init
+#define for_each_irq_pin(entry, head) \
+        for (entry = head; entry; entry = entry->next)
 
 /*
  *      Is the SiS APIC rmw bug present ?
@@ -85,6 +87,9 @@ int nr_ioapic_registers[MAX_IO_APICS];
 struct mpc_ioapic mp_ioapics[MAX_IO_APICS];
 int nr_ioapics;
 
+/* IO APIC gsi routing info */
+struct mp_ioapic_gsi  mp_gsi_routing[MAX_IO_APICS];
+
 /* MP IRQ source entries */
 struct mpc_intsrc mp_irqs[MAX_IRQ_SOURCES];
 
@@ -116,15 +121,6 @@ static int __init parse_noapic(char *str)
 }
 early_param("noapic", parse_noapic);
 
-struct irq_pin_list;
-
-/*
- * This is performance-critical, we want to do it O(1)
- *
- * the indexing order of this array favors 1:1 mappings
- * between pins and IRQs.
- */
-
 struct irq_pin_list {
         int apic, pin;
         struct irq_pin_list *next;
@@ -139,6 +135,11 @@ static struct irq_pin_list *get_one_free_irq_2_pin(int node)
         return pin;
 }
 
+/*
+ * This is performance-critical, we want to do it O(1)
+ *
+ * Most irqs are mapped 1:1 with pins.
+ */
 struct irq_cfg {
         struct irq_pin_list *irq_2_pin;
         cpumask_var_t domain;
@@ -414,13 +415,10 @@ static bool io_apic_level_ack_pending(struct irq_cfg *cfg)
         unsigned long flags;
 
         spin_lock_irqsave(&ioapic_lock, flags);
-        entry = cfg->irq_2_pin;
-        for (;;) {
+        for_each_irq_pin(entry, cfg->irq_2_pin) {
                 unsigned int reg;
                 int pin;
 
-                if (!entry)
-                        break;
                 pin = entry->pin;
                 reg = io_apic_read(entry->apic, 0x10 + pin*2);
                 /* Is the remote IRR bit set? */
@@ -428,9 +426,6 @@ static bool io_apic_level_ack_pending(struct irq_cfg *cfg)
                         spin_unlock_irqrestore(&ioapic_lock, flags);
                         return true;
                 }
-                if (!entry->next)
-                        break;
-                entry = entry->next;
         }
         spin_unlock_irqrestore(&ioapic_lock, flags);
 
@@ -498,72 +493,68 @@ static void ioapic_mask_entry(int apic, int pin)
  * shared ISA-space IRQs, so we have to support them. We are super
  * fast in the common case, and fast for shared ISA-space IRQs.
  */
-static void add_pin_to_irq_node(struct irq_cfg *cfg, int node, int apic, int pin)
+static int
+add_pin_to_irq_node_nopanic(struct irq_cfg *cfg, int node, int apic, int pin)
 {
-        struct irq_pin_list *entry;
+        struct irq_pin_list **last, *entry;
 
-        entry = cfg->irq_2_pin;
-        if (!entry) {
-                entry = get_one_free_irq_2_pin(node);
-                if (!entry) {
-                        printk(KERN_ERR "can not alloc irq_2_pin to add %d - %d\n",
-                                        apic, pin);
-                        return;
-                }
-                cfg->irq_2_pin = entry;
-                entry->apic = apic;
-                entry->pin = pin;
-                return;
-        }
-
-        while (entry->next) {
-                /* not again, please */
+        /* don't allow duplicates */
+        last = &cfg->irq_2_pin;
+        for_each_irq_pin(entry, cfg->irq_2_pin) {
                 if (entry->apic == apic && entry->pin == pin)
-                        return;
-
-                entry = entry->next;
+                        return 0;
+                last = &entry->next;
         }
 
-        entry->next = get_one_free_irq_2_pin(node);
-        entry = entry->next;
+        entry = get_one_free_irq_2_pin(node);
+        if (!entry) {
+                printk(KERN_ERR "can not alloc irq_pin_list (%d,%d,%d)\n",
+                                node, apic, pin);
+                return -ENOMEM;
+        }
         entry->apic = apic;
         entry->pin = pin;
+
+        *last = entry;
+        return 0;
+}
+
+static void add_pin_to_irq_node(struct irq_cfg *cfg, int node, int apic, int pin)
+{
+        if (add_pin_to_irq_node_nopanic(cfg, node, apic, pin))
+                panic("IO-APIC: failed to add irq-pin. Can not proceed\n");
 }
 
 /*
  * Reroute an IRQ to a different pin.
  */
 static void __init replace_pin_at_irq_node(struct irq_cfg *cfg, int node,
-                                      int oldapic, int oldpin,
-                                      int newapic, int newpin)
+                                           int oldapic, int oldpin,
+                                           int newapic, int newpin)
 {
-        struct irq_pin_list *entry = cfg->irq_2_pin;
-        int replaced = 0;
+        struct irq_pin_list *entry;
 
-        while (entry) {
+        for_each_irq_pin(entry, cfg->irq_2_pin) {
                 if (entry->apic == oldapic && entry->pin == oldpin) {
                         entry->apic = newapic;
                         entry->pin = newpin;
-                        replaced = 1;
                         /* every one is different, right? */
-                        break;
+                        return;
                 }
-                entry = entry->next;
         }
 
-        /* why? call replace before add? */
-        if (!replaced)
-                add_pin_to_irq_node(cfg, node, newapic, newpin);
+        /* old apic/pin didn't exist, so just add new ones */
+        add_pin_to_irq_node(cfg, node, newapic, newpin);
 }
 
-static inline void io_apic_modify_irq(struct irq_cfg *cfg,
-                                int mask_and, int mask_or,
-                                void (*final)(struct irq_pin_list *entry))
+static void io_apic_modify_irq(struct irq_cfg *cfg,
+                               int mask_and, int mask_or,
+                               void (*final)(struct irq_pin_list *entry))
 {
         int pin;
         struct irq_pin_list *entry;
 
-        for (entry = cfg->irq_2_pin; entry != NULL; entry = entry->next) {
+        for_each_irq_pin(entry, cfg->irq_2_pin) {
                 unsigned int reg;
                 pin = entry->pin;
                 reg = io_apic_read(entry->apic, 0x10 + pin * 2);
@@ -580,7 +571,6 @@ static void __unmask_IO_APIC_irq(struct irq_cfg *cfg)
         io_apic_modify_irq(cfg, ~IO_APIC_REDIR_MASKED, 0, NULL);
 }
 
-#ifdef CONFIG_X86_64
 static void io_apic_sync(struct irq_pin_list *entry)
 {
         /*
@@ -596,11 +586,6 @@ static void __mask_IO_APIC_irq(struct irq_cfg *cfg)
 {
         io_apic_modify_irq(cfg, ~0, IO_APIC_REDIR_MASKED, &io_apic_sync);
 }
-#else /* CONFIG_X86_32 */
-static void __mask_IO_APIC_irq(struct irq_cfg *cfg)
-{
-        io_apic_modify_irq(cfg, ~0, IO_APIC_REDIR_MASKED, NULL);
-}
 
 static void __mask_and_edge_IO_APIC_irq(struct irq_cfg *cfg)
 {
@@ -613,7 +598,6 @@ static void __unmask_and_level_IO_APIC_irq(struct irq_cfg *cfg)
         io_apic_modify_irq(cfg, ~IO_APIC_REDIR_MASKED,
                         IO_APIC_REDIR_LEVEL_TRIGGER, NULL);
 }
-#endif /* CONFIG_X86_32 */
 
 static void mask_IO_APIC_irq_desc(struct irq_desc *desc)
 {
@@ -1702,12 +1686,8 @@ __apicdebuginit(void) print_IO_APIC(void)
                 if (!entry)
                         continue;
                 printk(KERN_DEBUG "IRQ%d ", irq);
-                for (;;) {
+                for_each_irq_pin(entry, cfg->irq_2_pin)
                         printk("-> %d:%d", entry->apic, entry->pin);
-                        if (!entry->next)
-                                break;
-                        entry = entry->next;
-                }
                 printk("\n");
         }
 
@@ -2211,7 +2191,6 @@ static unsigned int startup_ioapic_irq(unsigned int irq)
         return was_pending;
 }
 
-#ifdef CONFIG_X86_64
 static int ioapic_retrigger_irq(unsigned int irq)
 {
 
@@ -2224,14 +2203,6 @@ static int ioapic_retrigger_irq(unsigned int irq)
 
         return 1;
 }
-#else
-static int ioapic_retrigger_irq(unsigned int irq)
-{
-        apic->send_IPI_self(irq_cfg(irq)->vector);
-
-        return 1;
-}
-#endif
 
 /*
  * Level and edge triggered IO-APIC interrupts need different handling,
@@ -2269,13 +2240,9 @@ static void __target_IO_APIC_irq(unsigned int irq, unsigned int dest, struct irq
         struct irq_pin_list *entry;
         u8 vector = cfg->vector;
 
-        entry = cfg->irq_2_pin;
-        for (;;) {
+        for_each_irq_pin(entry, cfg->irq_2_pin) {
                 unsigned int reg;
 
-                if (!entry)
-                        break;
-
                 apic = entry->apic;
                 pin = entry->pin;
                 /*
@@ -2288,9 +2255,6 @@ static void __target_IO_APIC_irq(unsigned int irq, unsigned int dest, struct irq
                 reg &= ~IO_APIC_REDIR_VECTOR_MASK;
                 reg |= vector;
                 io_apic_modify(apic, 0x10 + pin*2, reg);
-                if (!entry->next)
-                        break;
-                entry = entry->next;
         }
 }
 
@@ -2515,11 +2479,8 @@ atomic_t irq_mis_count;
 static void ack_apic_level(unsigned int irq)
 {
         struct irq_desc *desc = irq_to_desc(irq);
-
-#ifdef CONFIG_X86_32
         unsigned long v;
         int i;
-#endif
         struct irq_cfg *cfg;
         int do_unmask_irq = 0;
 
@@ -2532,31 +2493,28 @@ static void ack_apic_level(unsigned int irq)
         }
 #endif
 
-#ifdef CONFIG_X86_32
         /*
-        * It appears there is an erratum which affects at least version 0x11
-        * of I/O APIC (that's the 82093AA and cores integrated into various
-        * chipsets).  Under certain conditions a level-triggered interrupt is
-        * erroneously delivered as edge-triggered one but the respective IRR
-        * bit gets set nevertheless.  As a result the I/O unit expects an EOI
-        * message but it will never arrive and further interrupts are blocked
-        * from the source.  The exact reason is so far unknown, but the
-        * phenomenon was observed when two consecutive interrupt requests
-        * from a given source get delivered to the same CPU and the source is
-        * temporarily disabled in between.
-        *
-        * A workaround is to simulate an EOI message manually.  We achieve it
-        * by setting the trigger mode to edge and then to level when the edge
-        * trigger mode gets detected in the TMR of a local APIC for a
-        * level-triggered interrupt.  We mask the source for the time of the
-        * operation to prevent an edge-triggered interrupt escaping meanwhile.
-        * The idea is from Manfred Spraul.  --macro
-        */
+         * It appears there is an erratum which affects at least version 0x11
+         * of I/O APIC (that's the 82093AA and cores integrated into various
+         * chipsets).  Under certain conditions a level-triggered interrupt is
+         * erroneously delivered as edge-triggered one but the respective IRR
+         * bit gets set nevertheless.  As a result the I/O unit expects an EOI
+         * message but it will never arrive and further interrupts are blocked
+         * from the source.  The exact reason is so far unknown, but the
+         * phenomenon was observed when two consecutive interrupt requests
+         * from a given source get delivered to the same CPU and the source is
+         * temporarily disabled in between.
+         *
+         * A workaround is to simulate an EOI message manually.  We achieve it
+         * by setting the trigger mode to edge and then to level when the edge
+         * trigger mode gets detected in the TMR of a local APIC for a
+         * level-triggered interrupt.  We mask the source for the time of the
+         * operation to prevent an edge-triggered interrupt escaping meanwhile.
+         * The idea is from Manfred Spraul.  --macro
+         */
         cfg = desc->chip_data;
         i = cfg->vector;
-
         v = apic_read(APIC_TMR + ((i & ~0x1f) >> 1));
-#endif
 
         /*
          * We must acknowledge the irq before we move it or the acknowledge will
@@ -2598,7 +2556,7 @@ static void ack_apic_level(unsigned int irq)
                 unmask_IO_APIC_irq_desc(desc);
         }
 
-#ifdef CONFIG_X86_32
+        /* Tail end of version 0x11 I/O APIC bug workaround */
         if (!(v & (1 << (i & 0x1f)))) {
                 atomic_inc(&irq_mis_count);
                 spin_lock(&ioapic_lock);
@@ -2606,26 +2564,15 @@ static void ack_apic_level(unsigned int irq)
                 __unmask_and_level_IO_APIC_irq(cfg);
                 spin_unlock(&ioapic_lock);
         }
-#endif
 }
 
 #ifdef CONFIG_INTR_REMAP
 static void __eoi_ioapic_irq(unsigned int irq, struct irq_cfg *cfg)
 {
-        int apic, pin;
         struct irq_pin_list *entry;
 
-        entry = cfg->irq_2_pin;
-        for (;;) {
-
-                if (!entry)
-                        break;
-
-                apic = entry->apic;
-                pin = entry->pin;
-                io_apic_eoi(apic, pin);
-                entry = entry->next;
-        }
+        for_each_irq_pin(entry, cfg->irq_2_pin)
+                io_apic_eoi(entry->apic, entry->pin);
 }
 
 static void
@@ -3241,8 +3188,7 @@ void destroy_irq(unsigned int irq)
         cfg = desc->chip_data;
         dynamic_irq_cleanup(irq);
         /* connect back irq_cfg */
-        if (desc)
-                desc->chip_data = cfg;
+        desc->chip_data = cfg;
 
         free_irte(irq);
         spin_lock_irqsave(&vector_lock, flags);
@@ -3912,7 +3858,11 @@ static int __io_apic_set_pci_routing(struct device *dev, int irq,
          */
         if (irq >= NR_IRQS_LEGACY) {
                 cfg = desc->chip_data;
-                add_pin_to_irq_node(cfg, node, ioapic, pin);
+                if (add_pin_to_irq_node_nopanic(cfg, node, ioapic, pin)) {
+                        printk(KERN_INFO "can not add pin %d for irq %d\n",
+                                pin, irq);
+                        return 0;
+                }
         }
 
         setup_IO_APIC_irq(ioapic, pin, irq, desc, trigger, polarity);
@@ -3941,11 +3891,28 @@ int io_apic_set_pci_routing(struct device *dev, int irq,
         return __io_apic_set_pci_routing(dev, irq, irq_attr);
 }
 
-/* --------------------------------------------------------------------------
-                          ACPI-based IOAPIC Configuration
-   -------------------------------------------------------------------------- */
+u8 __init io_apic_unique_id(u8 id)
+{
+#ifdef CONFIG_X86_32
+        if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
+            !APIC_XAPIC(apic_version[boot_cpu_physical_apicid]))
+                return io_apic_get_unique_id(nr_ioapics, id);
+        else
+                return id;
+#else
+        int i;
+        DECLARE_BITMAP(used, 256);
 
-#ifdef CONFIG_ACPI
+        bitmap_zero(used, 256);
+        for (i = 0; i < nr_ioapics; i++) {
+                struct mpc_ioapic *ia = &mp_ioapics[i];
+                __set_bit(ia->apicid, used);
+        }
+        if (!test_bit(id, used))
+                return id;
+        return find_first_zero_bit(used, 256);
+#endif
+}
 
 #ifdef CONFIG_X86_32
 int __init io_apic_get_unique_id(int ioapic, int apic_id)
@@ -4054,8 +4021,6 @@ int acpi_get_override_irq(int bus_irq, int *trigger, int *polarity)
         return 0;
 }
 
-#endif /* CONFIG_ACPI */
-
 /*
  * This function currently is only a helper for the i386 smp boot process where
  * we need to reprogram the ioredtbls to cater for the cpus which have come online
@@ -4109,7 +4074,7 @@ void __init setup_ioapic_dest(void)
 
 static struct resource *ioapic_resources;
 
-static struct resource * __init ioapic_setup_resources(void)
+static struct resource * __init ioapic_setup_resources(int nr_ioapics)
 {
         unsigned long n;
         struct resource *res;
@@ -4125,15 +4090,13 @@ static struct resource * __init ioapic_setup_resources(void)
         mem = alloc_bootmem(n);
         res = (void *)mem;
 
-        if (mem != NULL) {
-                mem += sizeof(struct resource) * nr_ioapics;
+        mem += sizeof(struct resource) * nr_ioapics;
 
-                for (i = 0; i < nr_ioapics; i++) {
-                        res[i].name = mem;
-                        res[i].flags = IORESOURCE_MEM | IORESOURCE_BUSY;
-                        sprintf(mem,  "IOAPIC %u", i);
-                        mem += IOAPIC_RESOURCE_NAME_SIZE;
-                }
+        for (i = 0; i < nr_ioapics; i++) {
+                res[i].name = mem;
+                res[i].flags = IORESOURCE_MEM | IORESOURCE_BUSY;
+                sprintf(mem,  "IOAPIC %u", i);
+                mem += IOAPIC_RESOURCE_NAME_SIZE;
         }
 
         ioapic_resources = res;
@@ -4147,7 +4110,7 @@ void __init ioapic_init_mappings(void)
         struct resource *ioapic_res;
         int i;
 
-        ioapic_res = ioapic_setup_resources();
+        ioapic_res = ioapic_setup_resources(nr_ioapics);
         for (i = 0; i < nr_ioapics; i++) {
                 if (smp_found_config) {
                         ioapic_phys = mp_ioapics[i].apicaddr;
@@ -4176,11 +4139,9 @@ fake_ioapic_page:
                             __fix_to_virt(idx), ioapic_phys);
                 idx++;
 
-                if (ioapic_res != NULL) {
-                        ioapic_res->start = ioapic_phys;
-                        ioapic_res->end = ioapic_phys + (4 * 1024) - 1;
-                        ioapic_res++;
-                }
+                ioapic_res->start = ioapic_phys;
+                ioapic_res->end = ioapic_phys + (4 * 1024) - 1;
+                ioapic_res++;
         }
 }
 
@@ -4201,3 +4162,76 @@ void __init ioapic_insert_resources(void)
                 r++;
         }
 }
+
+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_gsi_routing[i].gsi_base)
+                    && (gsi <= mp_gsi_routing[i].gsi_end))
+                        return i;
+        }
+
+        printk(KERN_ERR "ERROR: Unable to locate IOAPIC for GSI %d\n", gsi);
+        return -1;
+}
+
+int mp_find_ioapic_pin(int ioapic, int gsi)
+{
+        if (WARN_ON(ioapic == -1))
+                return -1;
+        if (WARN_ON(gsi > mp_gsi_routing[ioapic].gsi_end))
+                return -1;
+
+        return gsi - mp_gsi_routing[ioapic].gsi_base;
+}
+
+static int bad_ioapic(unsigned long address)
+{
+        if (nr_ioapics >= MAX_IO_APICS) {
+                printk(KERN_WARNING "WARING: Max # of I/O APICs (%d) exceeded "
+                       "(found %d), skipping\n", MAX_IO_APICS, nr_ioapics);
+                return 1;
+        }
+        if (!address) {
+                printk(KERN_WARNING "WARNING: Bogus (zero) I/O APIC address"
+                       " found in table, skipping!\n");
+                return 1;
+        }
+        return 0;
+}
+
+void __init mp_register_ioapic(int id, u32 address, u32 gsi_base)
+{
+        int idx = 0;
+
+        if (bad_ioapic(address))
+                return;
+
+        idx = nr_ioapics;
+
+        mp_ioapics[idx].type = MP_IOAPIC;
+        mp_ioapics[idx].flags = MPC_APIC_USABLE;
+        mp_ioapics[idx].apicaddr = address;
+
+        set_fixmap_nocache(FIX_IO_APIC_BASE_0 + idx, address);
+        mp_ioapics[idx].apicid = io_apic_unique_id(id);
+        mp_ioapics[idx].apicver = io_apic_get_version(idx);
+
+        /*
+         * Build basic GSI lookup table to facilitate gsi->io_apic lookups
+         * and to prevent reprogramming of IOAPIC pins (PCI GSIs).
+         */
+        mp_gsi_routing[idx].gsi_base = gsi_base;
+        mp_gsi_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].apicid,
+               mp_ioapics[idx].apicver, mp_ioapics[idx].apicaddr,
+               mp_gsi_routing[idx].gsi_base, mp_gsi_routing[idx].gsi_end);
+
+        nr_ioapics++;
+}
diff --git a/arch/x86/kernel/apic/probe_64.c b/arch/x86/kernel/apic/probe_64.c
index fcec2f1d34a1..65edc180fc82 100644
--- a/arch/x86/kernel/apic/probe_64.c
+++ b/arch/x86/kernel/apic/probe_64.c
@@ -55,11 +55,11 @@ static int apicid_phys_pkg_id(int initial_apic_id, int index_msb)
 void __init default_setup_apic_routing(void)
 {
 #ifdef CONFIG_X86_X2APIC
-        if (x2apic_mode && (apic != &apic_x2apic_phys &&
+        if (x2apic_mode
 #ifdef CONFIG_X86_UV
-                       apic != &apic_x2apic_uv_x &&
+                       && apic != &apic_x2apic_uv_x
 #endif
-                       apic != &apic_x2apic_cluster)) {
+                       ) {
                 if (x2apic_phys)
                         apic = &apic_x2apic_phys;
                 else
diff --git a/arch/x86/kernel/mpparse.c b/arch/x86/kernel/mpparse.c
index 651c93b28862..fcd513bf2846 100644
--- a/arch/x86/kernel/mpparse.c
+++ b/arch/x86/kernel/mpparse.c
@@ -482,11 +482,11 @@ static void __init construct_ioapic_table(int mpc_default_type)
                 MP_bus_info(&bus);
         }
 
-        ioapic.type = MP_IOAPIC;
-        ioapic.apicid = 2;
-        ioapic.apicver = mpc_default_type > 4 ? 0x10 : 0x01;
-        ioapic.flags = MPC_APIC_USABLE;
-        ioapic.apicaddr = 0xFEC00000;
+        ioapic.type     = MP_IOAPIC;
+        ioapic.apicid   = 2;
+        ioapic.apicver  = mpc_default_type > 4 ? 0x10 : 0x01;
+        ioapic.flags    = MPC_APIC_USABLE;
+        ioapic.apicaddr = IO_APIC_DEFAULT_PHYS_BASE;
         MP_ioapic_info(&ioapic);
 
         /*