1 files changed, 540 insertions, 86 deletions

diff --git a/arch/x86/kernel/apic_64.c b/arch/x86/kernel/apic_64.c
index 446c062e831c..53898b65a6ae 100644
--- a/arch/x86/kernel/apic_64.c
+++ b/arch/x86/kernel/apic_64.c
@@ -27,6 +27,7 @@
 #include <linux/clockchips.h>
 #include <linux/acpi_pmtmr.h>
 #include <linux/module.h>
+#include <linux/dmar.h>
 
 #include <asm/atomic.h>
 #include <asm/smp.h>
@@ -39,13 +40,20 @@
 #include <asm/proto.h>
 #include <asm/timex.h>
 #include <asm/apic.h>
+#include <asm/i8259.h>
 
 #include <mach_ipi.h>
 #include <mach_apic.h>
 
+/* Disable local APIC timer from the kernel commandline or via dmi quirk */
 static int disable_apic_timer __cpuinitdata;
 static int apic_calibrate_pmtmr __initdata;
 int disable_apic;
+int disable_x2apic;
+int x2apic;
+
+/* x2apic enabled before OS handover */
+int x2apic_preenabled;
 
 /* Local APIC timer works in C2 */
 int local_apic_timer_c2_ok;
@@ -73,6 +81,9 @@ static void lapic_timer_setup(enum clock_event_mode mode,
 static void lapic_timer_broadcast(cpumask_t mask);
 static void apic_pm_activate(void);
 
+/*
+ * The local apic timer can be used for any function which is CPU local.
+ */
 static struct clock_event_device lapic_clockevent = {
         .name           = "lapic",
         .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
@@ -99,11 +110,15 @@ static inline int lapic_get_version(void)
 }
 
 /*
- * Check, if the APIC is integrated or a seperate chip
+ * Check, if the APIC is integrated or a separate chip
  */
 static inline int lapic_is_integrated(void)
 {
+#ifdef CONFIG_X86_64
         return 1;
+#else
+        return APIC_INTEGRATED(lapic_get_version());
+#endif
 }
 
 /*
@@ -118,13 +133,18 @@ static int modern_apic(void)
         return lapic_get_version() >= 0x14;
 }
 
-void apic_wait_icr_idle(void)
+/*
+ * Paravirt kernels also might be using these below ops. So we still
+ * use generic apic_read()/apic_write(), which might be pointing to different
+ * ops in PARAVIRT case.
+ */
+void xapic_wait_icr_idle(void)
 {
         while (apic_read(APIC_ICR) & APIC_ICR_BUSY)
                 cpu_relax();
 }
 
-u32 safe_apic_wait_icr_idle(void)
+u32 safe_xapic_wait_icr_idle(void)
 {
         u32 send_status;
         int timeout;
@@ -140,6 +160,68 @@ u32 safe_apic_wait_icr_idle(void)
         return send_status;
 }
 
+void xapic_icr_write(u32 low, u32 id)
+{
+        apic_write(APIC_ICR2, SET_APIC_DEST_FIELD(id));
+        apic_write(APIC_ICR, low);
+}
+
+u64 xapic_icr_read(void)
+{
+        u32 icr1, icr2;
+
+        icr2 = apic_read(APIC_ICR2);
+        icr1 = apic_read(APIC_ICR);
+
+        return icr1 | ((u64)icr2 << 32);
+}
+
+static struct apic_ops xapic_ops = {
+        .read = native_apic_mem_read,
+        .write = native_apic_mem_write,
+        .icr_read = xapic_icr_read,
+        .icr_write = xapic_icr_write,
+        .wait_icr_idle = xapic_wait_icr_idle,
+        .safe_wait_icr_idle = safe_xapic_wait_icr_idle,
+};
+
+struct apic_ops __read_mostly *apic_ops = &xapic_ops;
+EXPORT_SYMBOL_GPL(apic_ops);
+
+static void x2apic_wait_icr_idle(void)
+{
+        /* no need to wait for icr idle in x2apic */
+        return;
+}
+
+static u32 safe_x2apic_wait_icr_idle(void)
+{
+        /* no need to wait for icr idle in x2apic */
+        return 0;
+}
+
+void x2apic_icr_write(u32 low, u32 id)
+{
+        wrmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), ((__u64) id) << 32 | low);
+}
+
+u64 x2apic_icr_read(void)
+{
+        unsigned long val;
+
+        rdmsrl(APIC_BASE_MSR + (APIC_ICR >> 4), val);
+        return val;
+}
+
+static struct apic_ops x2apic_ops = {
+        .read = native_apic_msr_read,
+        .write = native_apic_msr_write,
+        .icr_read = x2apic_icr_read,
+        .icr_write = x2apic_icr_write,
+        .wait_icr_idle = x2apic_wait_icr_idle,
+        .safe_wait_icr_idle = safe_x2apic_wait_icr_idle,
+};
+
 /**
  * enable_NMI_through_LVT0 - enable NMI through local vector table 0
  */
@@ -149,6 +231,11 @@ void __cpuinit enable_NMI_through_LVT0(void)
 
         /* unmask and set to NMI */
         v = APIC_DM_NMI;
+
+        /* Level triggered for 82489DX (32bit mode) */
+        if (!lapic_is_integrated())
+                v |= APIC_LVT_LEVEL_TRIGGER;
+
         apic_write(APIC_LVT0, v);
 }
 
@@ -157,14 +244,28 @@ void __cpuinit enable_NMI_through_LVT0(void)
  */
 int lapic_get_maxlvt(void)
 {
-        unsigned int v, maxlvt;
+        unsigned int v;
 
         v = apic_read(APIC_LVR);
-        maxlvt = GET_APIC_MAXLVT(v);
-        return maxlvt;
+        /*
+         * - we always have APIC integrated on 64bit mode
+         * - 82489DXs do not report # of LVT entries
+         */
+        return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
 }
 
 /*
+ * Local APIC timer
+ */
+
+/* Clock divisor */
+#ifdef CONFG_X86_64
+#define APIC_DIVISOR 1
+#else
+#define APIC_DIVISOR 16
+#endif
+
+/*
  * This function sets up the local APIC timer, with a timeout of
  * 'clocks' APIC bus clock. During calibration we actually call
  * this function twice on the boot CPU, once with a bogus timeout
@@ -174,7 +275,6 @@ int lapic_get_maxlvt(void)
  * We do reads before writes even if unnecessary, to get around the
  * P5 APIC double write bug.
  */
-
 static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
 {
         unsigned int lvtt_value, tmp_value;
@@ -182,6 +282,9 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
         lvtt_value = LOCAL_TIMER_VECTOR;
         if (!oneshot)
                 lvtt_value |= APIC_LVT_TIMER_PERIODIC;
+        if (!lapic_is_integrated())
+                lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
+
         if (!irqen)
                 lvtt_value |= APIC_LVT_MASKED;
 
@@ -191,12 +294,12 @@ static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
          * Divide PICLK by 16
          */
         tmp_value = apic_read(APIC_TDCR);
-        apic_write(APIC_TDCR, (tmp_value
-                                & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
-                                | APIC_TDR_DIV_16);
+        apic_write(APIC_TDCR,
+                (tmp_value & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE)) |
+                APIC_TDR_DIV_16);
 
         if (!oneshot)
-                apic_write(APIC_TMICT, clocks);
+                apic_write(APIC_TMICT, clocks / APIC_DIVISOR);
 }
 
 /*
@@ -366,7 +469,7 @@ static int __init calibrate_APIC_clock(void)
         lapic_clockevent.min_delta_ns =
                 clockevent_delta2ns(0xF, &lapic_clockevent);
 
-        calibration_result = result / HZ;
+        calibration_result = (result * APIC_DIVISOR) / HZ;
 
         /*
          * Do a sanity check on the APIC calibration result
@@ -388,10 +491,10 @@ static int __init calibrate_APIC_clock(void)
 void __init setup_boot_APIC_clock(void)
 {
         /*
-         * The local apic timer can be disabled via the kernel commandline.
-         * Register the lapic timer as a dummy clock event source on SMP
-         * systems, so the broadcast mechanism is used. On UP systems simply
-         * ignore it.
+         * The local apic timer can be disabled via the kernel
+         * commandline or from the CPU detection code. Register the lapic
+         * timer as a dummy clock event source on SMP systems, so the
+         * broadcast mechanism is used. On UP systems simply ignore it.
          */
         if (disable_apic_timer) {
                 printk(KERN_INFO "Disabling APIC timer\n");
@@ -403,7 +506,9 @@ void __init setup_boot_APIC_clock(void)
                 return;
         }
 
-        printk(KERN_INFO "Using local APIC timer interrupts.\n");
+        apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n"
+                    "calibrating APIC timer ...\n");
+
         if (calibrate_APIC_clock()) {
                 /* No broadcast on UP ! */
                 if (num_possible_cpus() > 1)
@@ -422,6 +527,7 @@ void __init setup_boot_APIC_clock(void)
                 printk(KERN_WARNING "APIC timer registered as dummy,"
                         " due to nmi_watchdog=%d!\n", nmi_watchdog);
 
+        /* Setup the lapic or request the broadcast */
         setup_APIC_timer();
 }
 
@@ -460,7 +566,11 @@ static void local_apic_timer_interrupt(void)
         /*
          * the NMI deadlock-detector uses this.
          */
+#ifdef CONFIG_X86_64
         add_pda(apic_timer_irqs, 1);
+#else
+        per_cpu(irq_stat, cpu).apic_timer_irqs++;
+#endif
 
         evt->event_handler(evt);
 }
@@ -491,6 +601,7 @@ void smp_apic_timer_interrupt(struct pt_regs *regs)
         irq_enter();
         local_apic_timer_interrupt();
         irq_exit();
+
         set_irq_regs(old_regs);
 }
 
@@ -544,6 +655,13 @@ void clear_local_APIC(void)
                 apic_write(APIC_LVTPC, v | APIC_LVT_MASKED);
         }
 
+        /* lets not touch this if we didn't frob it */
+#if defined(CONFIG_X86_MCE_P4THERMAL) || defined(X86_MCE_INTEL)
+        if (maxlvt >= 5) {
+                v = apic_read(APIC_LVTTHMR);
+                apic_write(APIC_LVTTHMR, v | APIC_LVT_MASKED);
+        }
+#endif
         /*
          * Clean APIC state for other OSs:
          */
@@ -554,8 +672,14 @@ void clear_local_APIC(void)
                 apic_write(APIC_LVTERR, APIC_LVT_MASKED);
         if (maxlvt >= 4)
                 apic_write(APIC_LVTPC, APIC_LVT_MASKED);
-        apic_write(APIC_ESR, 0);
-        apic_read(APIC_ESR);
+
+        /* Integrated APIC (!82489DX) ? */
+        if (lapic_is_integrated()) {
+                if (maxlvt > 3)
+                        /* Clear ESR due to Pentium errata 3AP and 11AP */
+                        apic_write(APIC_ESR, 0);
+                apic_read(APIC_ESR);
+        }
 }
 
 /**
@@ -574,8 +698,28 @@ void disable_local_APIC(void)
         value = apic_read(APIC_SPIV);
         value &= ~APIC_SPIV_APIC_ENABLED;
         apic_write(APIC_SPIV, value);
+
+#ifdef CONFIG_X86_32
+        /*
+         * When LAPIC was disabled by the BIOS and enabled by the kernel,
+         * restore the disabled state.
+         */
+        if (enabled_via_apicbase) {
+                unsigned int l, h;
+
+                rdmsr(MSR_IA32_APICBASE, l, h);
+                l &= ~MSR_IA32_APICBASE_ENABLE;
+                wrmsr(MSR_IA32_APICBASE, l, h);
+        }
+#endif
 }
 
+/*
+ * If Linux enabled the LAPIC against the BIOS default disable it down before
+ * re-entering the BIOS on shutdown.  Otherwise the BIOS may get confused and
+ * not power-off.  Additionally clear all LVT entries before disable_local_APIC
+ * for the case where Linux didn't enable the LAPIC.
+ */
 void lapic_shutdown(void)
 {
         unsigned long flags;
@@ -585,7 +729,13 @@ void lapic_shutdown(void)
 
         local_irq_save(flags);
 
-        disable_local_APIC();
+#ifdef CONFIG_X86_32
+        if (!enabled_via_apicbase)
+                clear_local_APIC();
+        else
+#endif
+                disable_local_APIC();
+
 
         local_irq_restore(flags);
 }
@@ -629,10 +779,10 @@ int __init verify_local_APIC(void)
         /*
          * The ID register is read/write in a real APIC.
          */
-        reg0 = read_apic_id();
+        reg0 = apic_read(APIC_ID);
         apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
         apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
-        reg1 = read_apic_id();
+        reg1 = apic_read(APIC_ID);
         apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
         apic_write(APIC_ID, reg0);
         if (reg1 != (reg0 ^ APIC_ID_MASK))
@@ -656,8 +806,11 @@ int __init verify_local_APIC(void)
  */
 void __init sync_Arb_IDs(void)
 {
-        /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 */
-        if (modern_apic())
+        /*
+         * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
+         * needed on AMD.
+         */
+        if (modern_apic() || boot_cpu_data.x86_vendor == X86_VENDOR_AMD)
                 return;
 
         /*
@@ -666,8 +819,8 @@ void __init sync_Arb_IDs(void)
         apic_wait_icr_idle();
 
         apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
-        apic_write(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
-                                | APIC_DM_INIT);
+        apic_write(APIC_ICR, APIC_DEST_ALLINC |
+                        APIC_INT_LEVELTRIG | APIC_DM_INIT);
 }
 
 /*
@@ -684,8 +837,6 @@ void __init init_bsp_APIC(void)
         if (smp_found_config || !cpu_has_apic)
                 return;
 
-        value = apic_read(APIC_LVR);
-
         /*
          * Do not trust the local APIC being empty at bootup.
          */
@@ -697,7 +848,15 @@ void __init init_bsp_APIC(void)
         value = apic_read(APIC_SPIV);
         value &= ~APIC_VECTOR_MASK;
         value |= APIC_SPIV_APIC_ENABLED;
-        value |= APIC_SPIV_FOCUS_DISABLED;
+
+#ifdef CONFIG_X86_32
+        /* This bit is reserved on P4/Xeon and should be cleared */
+        if ((boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
+            (boot_cpu_data.x86 == 15))
+                value &= ~APIC_SPIV_FOCUS_DISABLED;
+        else
+#endif
+                value |= APIC_SPIV_FOCUS_DISABLED;
         value |= SPURIOUS_APIC_VECTOR;
         apic_write(APIC_SPIV, value);
 
@@ -706,9 +865,50 @@ void __init init_bsp_APIC(void)
          */
         apic_write(APIC_LVT0, APIC_DM_EXTINT);
         value = APIC_DM_NMI;
+        if (!lapic_is_integrated())             /* 82489DX */
+                value |= APIC_LVT_LEVEL_TRIGGER;
         apic_write(APIC_LVT1, value);
 }
 
+static void __cpuinit lapic_setup_esr(void)
+{
+        unsigned long oldvalue, value, maxlvt;
+        if (lapic_is_integrated() && !esr_disable) {
+                if (esr_disable) {
+                        /*
+                         * Something untraceable is creating bad interrupts on
+                         * secondary quads ... for the moment, just leave the
+                         * ESR disabled - we can't do anything useful with the
+                         * errors anyway - mbligh
+                         */
+                        printk(KERN_INFO "Leaving ESR disabled.\n");
+                        return;
+                }
+                /* !82489DX */
+                maxlvt = lapic_get_maxlvt();
+                if (maxlvt > 3)         /* Due to the Pentium erratum 3AP. */
+                        apic_write(APIC_ESR, 0);
+                oldvalue = apic_read(APIC_ESR);
+
+                /* enables sending errors */
+                value = ERROR_APIC_VECTOR;
+                apic_write(APIC_LVTERR, value);
+                /*
+                 * spec says clear errors after enabling vector.
+                 */
+                if (maxlvt > 3)
+                        apic_write(APIC_ESR, 0);
+                value = apic_read(APIC_ESR);
+                if (value != oldvalue)
+                        apic_printk(APIC_VERBOSE, "ESR value before enabling "
+                                "vector: 0x%08lx  after: 0x%08lx\n",
+                                oldvalue, value);
+        } else {
+                printk(KERN_INFO "No ESR for 82489DX.\n");
+        }
+}
+
+
 /**
  * setup_local_APIC - setup the local APIC
  */
@@ -814,25 +1014,143 @@ void __cpuinit setup_local_APIC(void)
         preempt_enable();
 }
 
-static void __cpuinit lapic_setup_esr(void)
-{
-        unsigned maxlvt = lapic_get_maxlvt();
-
-        apic_write(APIC_LVTERR, ERROR_APIC_VECTOR);
-        /*
-         * spec says clear errors after enabling vector.
-         */
-        if (maxlvt > 3)
-                apic_write(APIC_ESR, 0);
-}
-
 void __cpuinit end_local_APIC_setup(void)
 {
         lapic_setup_esr();
+
+#ifdef CONFIG_X86_32
+        {
+                unsigned int value;
+                /* Disable the local apic timer */
+                value = apic_read(APIC_LVTT);
+                value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
+                apic_write(APIC_LVTT, value);
+        }
+#endif
+
         setup_apic_nmi_watchdog(NULL);
         apic_pm_activate();
 }
 
+void check_x2apic(void)
+{
+        int msr, msr2;
+
+        rdmsr(MSR_IA32_APICBASE, msr, msr2);
+
+        if (msr & X2APIC_ENABLE) {
+                printk("x2apic enabled by BIOS, switching to x2apic ops\n");
+                x2apic_preenabled = x2apic = 1;
+                apic_ops = &x2apic_ops;
+        }
+}
+
+void enable_x2apic(void)
+{
+        int msr, msr2;
+
+        rdmsr(MSR_IA32_APICBASE, msr, msr2);
+        if (!(msr & X2APIC_ENABLE)) {
+                printk("Enabling x2apic\n");
+                wrmsr(MSR_IA32_APICBASE, msr | X2APIC_ENABLE, 0);
+        }
+}
+
+void enable_IR_x2apic(void)
+{
+#ifdef CONFIG_INTR_REMAP
+        int ret;
+        unsigned long flags;
+
+        if (!cpu_has_x2apic)
+                return;
+
+        if (!x2apic_preenabled && disable_x2apic) {
+                printk(KERN_INFO
+                       "Skipped enabling x2apic and Interrupt-remapping "
+                       "because of nox2apic\n");
+                return;
+        }
+
+        if (x2apic_preenabled && disable_x2apic)
+                panic("Bios already enabled x2apic, can't enforce nox2apic");
+
+        if (!x2apic_preenabled && skip_ioapic_setup) {
+                printk(KERN_INFO
+                       "Skipped enabling x2apic and Interrupt-remapping "
+                       "because of skipping io-apic setup\n");
+                return;
+        }
+
+        ret = dmar_table_init();
+        if (ret) {
+                printk(KERN_INFO
+                       "dmar_table_init() failed with %d:\n", ret);
+
+                if (x2apic_preenabled)
+                        panic("x2apic enabled by bios. But IR enabling failed");
+                else
+                        printk(KERN_INFO
+                               "Not enabling x2apic,Intr-remapping\n");
+                return;
+        }
+
+        local_irq_save(flags);
+        mask_8259A();
+        save_mask_IO_APIC_setup();
+
+        ret = enable_intr_remapping(1);
+
+        if (ret && x2apic_preenabled) {
+                local_irq_restore(flags);
+                panic("x2apic enabled by bios. But IR enabling failed");
+        }
+
+        if (ret)
+                goto end;
+
+        if (!x2apic) {
+                x2apic = 1;
+                apic_ops = &x2apic_ops;
+                enable_x2apic();
+        }
+end:
+        if (ret)
+                /*
+                 * IR enabling failed
+                 */
+                restore_IO_APIC_setup();
+        else
+                reinit_intr_remapped_IO_APIC(x2apic_preenabled);
+
+        unmask_8259A();
+        local_irq_restore(flags);
+
+        if (!ret) {
+                if (!x2apic_preenabled)
+                        printk(KERN_INFO
+                               "Enabled x2apic and interrupt-remapping\n");
+                else
+                        printk(KERN_INFO
+                               "Enabled Interrupt-remapping\n");
+        } else
+                printk(KERN_ERR
+                       "Failed to enable Interrupt-remapping and x2apic\n");
+#else
+        if (!cpu_has_x2apic)
+                return;
+
+        if (x2apic_preenabled)
+                panic("x2apic enabled prior OS handover,"
+                      " enable CONFIG_INTR_REMAP");
+
+        printk(KERN_INFO "Enable CONFIG_INTR_REMAP for enabling intr-remapping "
+               " and x2apic\n");
+#endif
+
+        return;
+}
+
 /*
  * Detect and enable local APICs on non-SMP boards.
  * Original code written by Keir Fraser.
@@ -872,7 +1190,7 @@ void __init early_init_lapic_mapping(void)
          * Fetch the APIC ID of the BSP in case we have a
          * default configuration (or the MP table is broken).
          */
-        boot_cpu_physical_apicid = GET_APIC_ID(read_apic_id());
+        boot_cpu_physical_apicid = read_apic_id();
 }
 
 /**
@@ -880,6 +1198,11 @@ void __init early_init_lapic_mapping(void)
  */
 void __init init_apic_mappings(void)
 {
+        if (x2apic) {
+                boot_cpu_physical_apicid = read_apic_id();
+                return;
+        }
+
         /*
          * If no local APIC can be found then set up a fake all
          * zeroes page to simulate the local APIC and another
@@ -899,13 +1222,15 @@ void __init init_apic_mappings(void)
          * Fetch the APIC ID of the BSP in case we have a
          * default configuration (or the MP table is broken).
          */
-        boot_cpu_physical_apicid = GET_APIC_ID(read_apic_id());
+        boot_cpu_physical_apicid = read_apic_id();
 }
 
 /*
  * This initializes the IO-APIC and APIC hardware if this is
  * a UP kernel.
  */
+int apic_version[MAX_APICS];
+
 int __init APIC_init_uniprocessor(void)
 {
         if (disable_apic) {
@@ -918,6 +1243,9 @@ int __init APIC_init_uniprocessor(void)
                 return -1;
         }
 
+        enable_IR_x2apic();
+        setup_apic_routing();
+
         verify_local_APIC();
 
         connect_bsp_APIC();
@@ -1004,17 +1332,57 @@ asmlinkage void smp_error_interrupt(void)
 }
 
 /**
- *  * connect_bsp_APIC - attach the APIC to the interrupt system
- *   */
+ * connect_bsp_APIC - attach the APIC to the interrupt system
+ */
 void __init connect_bsp_APIC(void)
 {
+#ifdef CONFIG_X86_32
+        if (pic_mode) {
+                /*
+                 * Do not trust the local APIC being empty at bootup.
+                 */
+                clear_local_APIC();
+                /*
+                 * PIC mode, enable APIC mode in the IMCR, i.e.  connect BSP's
+                 * local APIC to INT and NMI lines.
+                 */
+                apic_printk(APIC_VERBOSE, "leaving PIC mode, "
+                                "enabling APIC mode.\n");
+                outb(0x70, 0x22);
+                outb(0x01, 0x23);
+        }
+#endif
         enable_apic_mode();
 }
 
+/**
+ * disconnect_bsp_APIC - detach the APIC from the interrupt system
+ * @virt_wire_setup:    indicates, whether virtual wire mode is selected
+ *
+ * Virtual wire mode is necessary to deliver legacy interrupts even when the
+ * APIC is disabled.
+ */
 void disconnect_bsp_APIC(int virt_wire_setup)
 {
+        unsigned int value;
+
+#ifdef CONFIG_X86_32
+        if (pic_mode) {
+                /*
+                 * Put the board back into PIC mode (has an effect only on
+                 * certain older boards).  Note that APIC interrupts, including
+                 * IPIs, won't work beyond this point!  The only exception are
+                 * INIT IPIs.
+                 */
+                apic_printk(APIC_VERBOSE, "disabling APIC mode, "
+                                "entering PIC mode.\n");
+                outb(0x70, 0x22);
+                outb(0x00, 0x23);
+                return;
+        }
+#endif
+
         /* Go back to Virtual Wire compatibility mode */
-        unsigned long value;
 
         /* For the spurious interrupt use vector F, and enable it */
         value = apic_read(APIC_SPIV);
@@ -1040,7 +1408,10 @@ void disconnect_bsp_APIC(int virt_wire_setup)
                 apic_write(APIC_LVT0, APIC_LVT_MASKED);
         }
 
-        /* For LVT1 make it edge triggered, active high, nmi and enabled */
+        /*
+         * For LVT1 make it edge triggered, active high,
+         * nmi and enabled
+         */
         value = apic_read(APIC_LVT1);
         value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
                         APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
@@ -1055,9 +1426,20 @@ void __cpuinit generic_processor_info(int apicid, int version)
         int cpu;
         cpumask_t tmp_map;
 
+        /*
+         * Validate version
+         */
+        if (version == 0x0) {
+                printk(KERN_WARNING "BIOS bug, APIC version is 0 for CPU#%d! "
+                                "fixing up to 0x10. (tell your hw vendor)\n",
+                                version);
+                version = 0x10;
+        }
+        apic_version[apicid] = version;
+
         if (num_processors >= NR_CPUS) {
                 printk(KERN_WARNING "WARNING: NR_CPUS limit of %i reached."
-                       " Processor ignored.\n", NR_CPUS);
+                        "  Processor ignored.\n", NR_CPUS);
                 return;
         }
 
@@ -1077,6 +1459,29 @@ void __cpuinit generic_processor_info(int apicid, int version)
         if (apicid > max_physical_apicid)
                 max_physical_apicid = apicid;
 
+#ifdef CONFIG_X86_32
+        /*
+         * Would be preferable to switch to bigsmp when CONFIG_HOTPLUG_CPU=y
+         * but we need to work other dependencies like SMP_SUSPEND etc
+         * before this can be done without some confusion.
+         * if (CPU_HOTPLUG_ENABLED || num_processors > 8)
+         *       - Ashok Raj <ashok.raj@intel.com>
+         */
+        if (max_physical_apicid >= 8) {
+                switch (boot_cpu_data.x86_vendor) {
+                case X86_VENDOR_INTEL:
+                        if (!APIC_XAPIC(version)) {
+                                def_to_bigsmp = 0;
+                                break;
+                        }
+                        /* If P4 and above fall through */
+                case X86_VENDOR_AMD:
+                        def_to_bigsmp = 1;
+                }
+        }
+#endif
+
+#if defined(CONFIG_X86_SMP) || defined(CONFIG_X86_64)
         /* are we being called early in kernel startup? */
         if (early_per_cpu_ptr(x86_cpu_to_apicid)) {
                 u16 *cpu_to_apicid = early_per_cpu_ptr(x86_cpu_to_apicid);
@@ -1088,20 +1493,28 @@ void __cpuinit generic_processor_info(int apicid, int version)
                 per_cpu(x86_cpu_to_apicid, cpu) = apicid;
                 per_cpu(x86_bios_cpu_apicid, cpu) = apicid;
         }
+#endif
 
         cpu_set(cpu, cpu_possible_map);
         cpu_set(cpu, cpu_present_map);
 }
 
+int hard_smp_processor_id(void)
+{
+        return read_apic_id();
+}
+
 /*
  * Power management
  */
 #ifdef CONFIG_PM
 
 static struct {
-        /* 'active' is true if the local APIC was enabled by us and
-           not the BIOS; this signifies that we are also responsible
-           for disabling it before entering apm/acpi suspend */
+        /*
+         * 'active' is true if the local APIC was enabled by us and
+         * not the BIOS; this signifies that we are also responsible
+         * for disabling it before entering apm/acpi suspend
+         */
         int active;
         /* r/w apic fields */
         unsigned int apic_id;
@@ -1129,7 +1542,7 @@ static int lapic_suspend(struct sys_device *dev, pm_message_t state)
 
         maxlvt = lapic_get_maxlvt();
 
-        apic_pm_state.apic_id = read_apic_id();
+        apic_pm_state.apic_id = apic_read(APIC_ID);
         apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
         apic_pm_state.apic_ldr = apic_read(APIC_LDR);
         apic_pm_state.apic_dfr = apic_read(APIC_DFR);
@@ -1142,10 +1555,11 @@ static int lapic_suspend(struct sys_device *dev, pm_message_t state)
         apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
         apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
         apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
-#ifdef CONFIG_X86_MCE_INTEL
+#if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
         if (maxlvt >= 5)
                 apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
 #endif
+
         local_irq_save(flags);
         disable_local_APIC();
         local_irq_restore(flags);
@@ -1164,10 +1578,25 @@ static int lapic_resume(struct sys_device *dev)
         maxlvt = lapic_get_maxlvt();
 
         local_irq_save(flags);
-        rdmsr(MSR_IA32_APICBASE, l, h);
-        l &= ~MSR_IA32_APICBASE_BASE;
-        l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
-        wrmsr(MSR_IA32_APICBASE, l, h);
+
+#ifdef CONFIG_X86_64
+        if (x2apic)
+                enable_x2apic();
+        else
+#endif
+        {
+                /*
+                 * Make sure the APICBASE points to the right address
+                 *
+                 * FIXME! This will be wrong if we ever support suspend on
+                 * SMP! We'll need to do this as part of the CPU restore!
+                 */
+                rdmsr(MSR_IA32_APICBASE, l, h);
+                l &= ~MSR_IA32_APICBASE_BASE;
+                l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
+                wrmsr(MSR_IA32_APICBASE, l, h);
+        }
+
         apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
         apic_write(APIC_ID, apic_pm_state.apic_id);
         apic_write(APIC_DFR, apic_pm_state.apic_dfr);
@@ -1176,7 +1605,7 @@ static int lapic_resume(struct sys_device *dev)
         apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
         apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
         apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
-#ifdef CONFIG_X86_MCE_INTEL
+#if defined(CONFIG_X86_MCE_P4THERMAL) || defined(CONFIG_X86_MCE_INTEL)
         if (maxlvt >= 5)
                 apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
 #endif
@@ -1190,10 +1619,17 @@ static int lapic_resume(struct sys_device *dev)
         apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
         apic_write(APIC_ESR, 0);
         apic_read(APIC_ESR);
+
         local_irq_restore(flags);
+
         return 0;
 }
 
+/*
+ * This device has no shutdown method - fully functioning local APICs
+ * are needed on every CPU up until machine_halt/restart/poweroff.
+ */
+
 static struct sysdev_class lapic_sysclass = {
         .name           = "lapic",
         .resume         = lapic_resume,
@@ -1307,31 +1743,19 @@ __cpuinit int apic_is_clustered_box(void)
         return (clusters > 2);
 }
 
-/*
- * APIC command line parameters
- */
-static int __init apic_set_verbosity(char *str)
+static __init int setup_nox2apic(char *str)
 {
-        if (str == NULL)  {
-                skip_ioapic_setup = 0;
-                ioapic_force = 1;
-                return 0;
-        }
-        if (strcmp("debug", str) == 0)
-                apic_verbosity = APIC_DEBUG;
-        else if (strcmp("verbose", str) == 0)
-                apic_verbosity = APIC_VERBOSE;
-        else {
-                printk(KERN_WARNING "APIC Verbosity level %s not recognised"
-                                " use apic=verbose or apic=debug\n", str);
-                return -EINVAL;
-        }
-
+        disable_x2apic = 1;
+        clear_cpu_cap(&boot_cpu_data, X86_FEATURE_X2APIC);
         return 0;
 }
-early_param("apic", apic_set_verbosity);
+early_param("nox2apic", setup_nox2apic);
+
 
-static __init int setup_disableapic(char *str)
+/*
+ * APIC command line parameters
+ */
+static int __init setup_disableapic(char *arg)
 {
         disable_apic = 1;
         setup_clear_cpu_cap(X86_FEATURE_APIC);
@@ -1340,9 +1764,9 @@ static __init int setup_disableapic(char *str)
 early_param("disableapic", setup_disableapic);
 
 /* same as disableapic, for compatibility */
-static __init int setup_nolapic(char *str)
+static int __init setup_nolapic(char *arg)
 {
-        return setup_disableapic(str);
+        return setup_disableapic(arg);
 }
 early_param("nolapic", setup_nolapic);
 
@@ -1353,14 +1777,19 @@ static int __init parse_lapic_timer_c2_ok(char *arg)
 }
 early_param("lapic_timer_c2_ok", parse_lapic_timer_c2_ok);
 
-static __init int setup_noapictimer(char *str)
+static int __init parse_disable_apic_timer(char *arg)
 {
-        if (str[0] != ' ' && str[0] != 0)
-                return 0;
         disable_apic_timer = 1;
-        return 1;
+        return 0;
 }
-__setup("noapictimer", setup_noapictimer);
+early_param("noapictimer", parse_disable_apic_timer);
+
+static int __init parse_nolapic_timer(char *arg)
+{
+        disable_apic_timer = 1;
+        return 0;
+}
+early_param("nolapic_timer", parse_nolapic_timer);
 
 static __init int setup_apicpmtimer(char *s)
 {
@@ -1370,6 +1799,31 @@ static __init int setup_apicpmtimer(char *s)
 }
 __setup("apicpmtimer", setup_apicpmtimer);
 
+static int __init apic_set_verbosity(char *arg)
+{
+        if (!arg)  {
+#ifdef CONFIG_X86_64
+                skip_ioapic_setup = 0;
+                ioapic_force = 1;
+                return 0;
+#endif
+                return -EINVAL;
+        }
+
+        if (strcmp("debug", arg) == 0)
+                apic_verbosity = APIC_DEBUG;
+        else if (strcmp("verbose", arg) == 0)
+                apic_verbosity = APIC_VERBOSE;
+        else {
+                printk(KERN_WARNING "APIC Verbosity level %s not recognised"
+                        " use apic=verbose or apic=debug\n", arg);
+                return -EINVAL;
+        }
+
+        return 0;
+}
+early_param("apic", apic_set_verbosity);
+
 static int __init lapic_insert_resource(void)
 {
         if (!apic_phys)