[PATCH] i386, apic: clean up the APIC code
authorThomas Gleixner <tglx@linutronix.de>
Fri, 16 Feb 2007 09:27:58 +0000 (01:27 -0800)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Fri, 16 Feb 2007 16:13:58 +0000 (08:13 -0800)
The apic code is quite unstructured and missing a lot of comments.

- Restructure the code into helper functions, timer, setup/shutdown,
  interrupt and power management blocks.
- Fixup comments.
- Namespace fixups
- Inline helpers for version and is_integrated
- Combine the ack_bad_irq functions

No functional changes.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Zachary Amsden <zach@vmware.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rohit Seth <rohitseth@google.com>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
arch/i386/kernel/apic.c
arch/i386/kernel/io_apic.c
arch/i386/kernel/irq.c
arch/i386/kernel/smpboot.c
include/asm-i386/apic.h

index f4159e0..b56448f 100644 (file)
 #include "io_ports.h"
 
 /*
+ * Sanity check
+ */
+#if (SPURIOUS_APIC_VECTOR & 0x0F) != 0x0F
+# error SPURIOUS_APIC_VECTOR definition error
+#endif
+
+/*
  * cpu_mask that denotes the CPUs that needs timer interrupt coming in as
  * IPIs in place of local APIC timers
  */
@@ -52,561 +59,560 @@ static cpumask_t timer_bcast_ipi;
 
 /*
  * Knob to control our willingness to enable the local APIC.
+ *
+ * -1=force-disable, +1=force-enable
  */
-static int enable_local_apic __initdata = 0; /* -1=force-disable, +1=force-enable */
-
-static inline void lapic_disable(void)
-{
-       enable_local_apic = -1;
-       clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
-}
-
-static inline void lapic_enable(void)
-{
-       enable_local_apic = 1;
-}
+static int enable_local_apic __initdata = 0;
 
 /*
- * Debug level
+ * Debug level, exported for io_apic.c
  */
 int apic_verbosity;
 
-
 static void apic_pm_activate(void);
 
-static int modern_apic(void)
+
+/* Using APIC to generate smp_local_timer_interrupt? */
+int using_apic_timer __read_mostly = 0;
+
+/* Local APIC was disabled by the BIOS and enabled by the kernel */
+static int enabled_via_apicbase;
+
+/*
+ * Get the LAPIC version
+ */
+static inline int lapic_get_version(void)
 {
-       unsigned int lvr, version;
-       /* AMD systems use old APIC versions, so check the CPU */
-       if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
-               boot_cpu_data.x86 >= 0xf)
-               return 1;
-       lvr = apic_read(APIC_LVR);
-       version = GET_APIC_VERSION(lvr);
-       return version >= 0x14;
+       return GET_APIC_VERSION(apic_read(APIC_LVR));
 }
 
 /*
- * 'what should we do if we get a hw irq event on an illegal vector'.
- * each architecture has to answer this themselves.
+ * Check, if the APIC is integrated or a seperate chip
  */
-void ack_bad_irq(unsigned int irq)
+static inline int lapic_is_integrated(void)
 {
-       printk("unexpected IRQ trap at vector %02x\n", irq);
-       /*
-        * Currently unexpected vectors happen only on SMP and APIC.
-        * We _must_ ack these because every local APIC has only N
-        * irq slots per priority level, and a 'hanging, unacked' IRQ
-        * holds up an irq slot - in excessive cases (when multiple
-        * unexpected vectors occur) that might lock up the APIC
-        * completely.
-        * But only ack when the APIC is enabled -AK
-        */
-       if (cpu_has_apic)
-               ack_APIC_irq();
+       return APIC_INTEGRATED(lapic_get_version());
 }
 
-void __init apic_intr_init(void)
+/*
+ * Check, whether this is a modern or a first generation APIC
+ */
+static int modern_apic(void)
 {
-#ifdef CONFIG_SMP
-       smp_intr_init();
-#endif
-       /* self generated IPI for local APIC timer */
-       set_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
-
-       /* IPI vectors for APIC spurious and error interrupts */
-       set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
-       set_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
-
-       /* thermal monitor LVT interrupt */
-#ifdef CONFIG_X86_MCE_P4THERMAL
-       set_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
-#endif
+       /* AMD systems use old APIC versions, so check the CPU */
+       if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
+           boot_cpu_data.x86 >= 0xf)
+               return 1;
+       return lapic_get_version() >= 0x14;
 }
 
-/* Using APIC to generate smp_local_timer_interrupt? */
-int using_apic_timer __read_mostly = 0;
-
-static int enabled_via_apicbase;
-
+/**
+ * enable_NMI_through_LVT0 - enable NMI through local vector table 0
+ */
 void enable_NMI_through_LVT0 (void * dummy)
 {
-       unsigned int v, ver;
+       unsigned int v = APIC_DM_NMI;
 
-       ver = apic_read(APIC_LVR);
-       ver = GET_APIC_VERSION(ver);
-       v = APIC_DM_NMI;                        /* unmask and set to NMI */
-       if (!APIC_INTEGRATED(ver))              /* 82489DX */
+       /* Level triggered for 82489DX */
+       if (!lapic_is_integrated())
                v |= APIC_LVT_LEVEL_TRIGGER;
        apic_write_around(APIC_LVT0, v);
 }
 
+/**
+ * get_physical_broadcast - Get number of physical broadcast IDs
+ */
 int get_physical_broadcast(void)
 {
-       if (modern_apic())
-               return 0xff;
-       else
-               return 0xf;
+       return modern_apic() ? 0xff : 0xf;
 }
 
-int get_maxlvt(void)
+/**
+ * lapic_get_maxlvt - get the maximum number of local vector table entries
+ */
+int lapic_get_maxlvt(void)
 {
-       unsigned int v, ver, maxlvt;
+       unsigned int v = apic_read(APIC_LVR);
 
-       v = apic_read(APIC_LVR);
-       ver = GET_APIC_VERSION(v);
        /* 82489DXs do not report # of LVT entries. */
-       maxlvt = APIC_INTEGRATED(ver) ? GET_APIC_MAXLVT(v) : 2;
-       return maxlvt;
+       return APIC_INTEGRATED(GET_APIC_VERSION(v)) ? GET_APIC_MAXLVT(v) : 2;
 }
 
-void clear_local_APIC(void)
+/*
+ * Local APIC timer
+ */
+
+/*
+ * This part sets up the APIC 32 bit clock in LVTT1, with HZ interrupts
+ * per second. We assume that the caller has already set up the local
+ * APIC.
+ *
+ * The APIC timer is not exactly sync with the external timer chip, it
+ * closely follows bus clocks.
+ */
+
+/*
+ * The timer chip is already set up at HZ interrupts per second here,
+ * but we do not accept timer interrupts yet. We only allow the BP
+ * to calibrate.
+ */
+static unsigned int __devinit get_8254_timer_count(void)
 {
-       int maxlvt;
-       unsigned long v;
+       unsigned long flags;
 
-       maxlvt = get_maxlvt();
+       unsigned int count;
 
-       /*
-        * Masking an LVT entry can trigger a local APIC error
-        * if the vector is zero. Mask LVTERR first to prevent this.
-        */
-       if (maxlvt >= 3) {
-               v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
-               apic_write_around(APIC_LVTERR, v | APIC_LVT_MASKED);
-       }
-       /*
-        * Careful: we have to set masks only first to deassert
-        * any level-triggered sources.
-        */
-       v = apic_read(APIC_LVTT);
-       apic_write_around(APIC_LVTT, v | APIC_LVT_MASKED);
-       v = apic_read(APIC_LVT0);
-       apic_write_around(APIC_LVT0, v | APIC_LVT_MASKED);
-       v = apic_read(APIC_LVT1);
-       apic_write_around(APIC_LVT1, v | APIC_LVT_MASKED);
-       if (maxlvt >= 4) {
-               v = apic_read(APIC_LVTPC);
-               apic_write_around(APIC_LVTPC, v | APIC_LVT_MASKED);
-       }
+       spin_lock_irqsave(&i8253_lock, flags);
 
-/* lets not touch this if we didn't frob it */
-#ifdef CONFIG_X86_MCE_P4THERMAL
-       if (maxlvt >= 5) {
-               v = apic_read(APIC_LVTTHMR);
-               apic_write_around(APIC_LVTTHMR, v | APIC_LVT_MASKED);
-       }
-#endif
-       /*
-        * Clean APIC state for other OSs:
-        */
-       apic_write_around(APIC_LVTT, APIC_LVT_MASKED);
-       apic_write_around(APIC_LVT0, APIC_LVT_MASKED);
-       apic_write_around(APIC_LVT1, APIC_LVT_MASKED);
-       if (maxlvt >= 3)
-               apic_write_around(APIC_LVTERR, APIC_LVT_MASKED);
-       if (maxlvt >= 4)
-               apic_write_around(APIC_LVTPC, APIC_LVT_MASKED);
+       outb_p(0x00, PIT_MODE);
+       count = inb_p(PIT_CH0);
+       count |= inb_p(PIT_CH0) << 8;
 
-#ifdef CONFIG_X86_MCE_P4THERMAL
-       if (maxlvt >= 5)
-               apic_write_around(APIC_LVTTHMR, APIC_LVT_MASKED);
-#endif
-       v = GET_APIC_VERSION(apic_read(APIC_LVR));
-       if (APIC_INTEGRATED(v)) {       /* !82489DX */
-               if (maxlvt > 3)         /* Due to Pentium errata 3AP and 11AP. */
-                       apic_write(APIC_ESR, 0);
-               apic_read(APIC_ESR);
-       }
-}
+       spin_unlock_irqrestore(&i8253_lock, flags);
 
-void __init connect_bsp_APIC(void)
-{
-       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);
-       }
-       enable_apic_mode();
+       return count;
 }
 
-void disconnect_bsp_APIC(int virt_wire_setup)
+/* next tick in 8254 can be caught by catching timer wraparound */
+static void __devinit wait_8254_wraparound(void)
 {
-       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);
-       }
-       else {
-               /* Go back to Virtual Wire compatibility mode */
-               unsigned long value;
+       unsigned int curr_count, prev_count;
 
-               /* For the spurious interrupt use vector F, and enable it */
-               value = apic_read(APIC_SPIV);
-               value &= ~APIC_VECTOR_MASK;
-               value |= APIC_SPIV_APIC_ENABLED;
-               value |= 0xf;
-               apic_write_around(APIC_SPIV, value);
+       curr_count = get_8254_timer_count();
+       do {
+               prev_count = curr_count;
+               curr_count = get_8254_timer_count();
 
-               if (!virt_wire_setup) {
-                       /* For LVT0 make it edge triggered, active high, external and enabled */
-                       value = apic_read(APIC_LVT0);
-                       value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
-                               APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
-                               APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED );
-                       value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
-                       value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
-                       apic_write_around(APIC_LVT0, value);
-               }
-               else {
-                       /* Disable LVT0 */
-                       apic_write_around(APIC_LVT0, APIC_LVT_MASKED);
-               }
+               /* workaround for broken Mercury/Neptune */
+               if (prev_count >= curr_count + 0x100)
+                       curr_count = get_8254_timer_count();
 
-               /* 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 |
-                       APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
-               value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
-               value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
-               apic_write_around(APIC_LVT1, value);
-       }
+       } while (prev_count >= curr_count);
 }
 
-void disable_local_APIC(void)
+/*
+ * Default initialization for 8254 timers. If we use other timers like HPET,
+ * we override this later
+ */
+void (*wait_timer_tick)(void) __devinitdata = wait_8254_wraparound;
+
+/*
+ * 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
+ * value, second time for real. The other (noncalibrating) CPUs
+ * call this function only once, with the real, calibrated value.
+ *
+ * We do reads before writes even if unnecessary, to get around the
+ * P5 APIC double write bug.
+ */
+
+#define APIC_DIVISOR 16
+
+static void __setup_APIC_LVTT(unsigned int clocks)
 {
-       unsigned long value;
+       unsigned int lvtt_value, tmp_value;
+       int cpu = smp_processor_id();
 
-       clear_local_APIC();
+       lvtt_value = APIC_LVT_TIMER_PERIODIC | LOCAL_TIMER_VECTOR;
+       if (!lapic_is_integrated())
+               lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
+
+       if (cpu_isset(cpu, timer_bcast_ipi))
+               lvtt_value |= APIC_LVT_MASKED;
+
+       apic_write_around(APIC_LVTT, lvtt_value);
 
        /*
-        * Disable APIC (implies clearing of registers
-        * for 82489DX!).
+        * Divide PICLK by 16
         */
-       value = apic_read(APIC_SPIV);
-       value &= ~APIC_SPIV_APIC_ENABLED;
-       apic_write_around(APIC_SPIV, value);
+       tmp_value = apic_read(APIC_TDCR);
+       apic_write_around(APIC_TDCR, (tmp_value
+                               & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
+                               | APIC_TDR_DIV_16);
 
-       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);
-       }
+       apic_write_around(APIC_TMICT, clocks/APIC_DIVISOR);
 }
 
-/*
- * This is to verify that we're looking at a real local APIC.
- * Check these against your board if the CPUs aren't getting
- * started for no apparent reason.
- */
-int __init verify_local_APIC(void)
+static void __devinit setup_APIC_timer(unsigned int clocks)
 {
-       unsigned int reg0, reg1;
+       unsigned long flags;
+
+       local_irq_save(flags);
 
        /*
-        * The version register is read-only in a real APIC.
+        * Wait for IRQ0's slice:
         */
-       reg0 = apic_read(APIC_LVR);
-       apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
-       apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
-       reg1 = apic_read(APIC_LVR);
-       apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
+       wait_timer_tick();
+
+       __setup_APIC_LVTT(clocks);
+
+       local_irq_restore(flags);
+}
+
+/*
+ * In this function we calibrate APIC bus clocks to the external
+ * timer. Unfortunately we cannot use jiffies and the timer irq
+ * to calibrate, since some later bootup code depends on getting
+ * the first irq? Ugh.
+ *
+ * We want to do the calibration only once since we
+ * want to have local timer irqs syncron. CPUs connected
+ * by the same APIC bus have the very same bus frequency.
+ * And we want to have irqs off anyways, no accidental
+ * APIC irq that way.
+ */
+
+static int __init calibrate_APIC_clock(void)
+{
+       unsigned long long t1 = 0, t2 = 0;
+       long tt1, tt2;
+       long result;
+       int i;
+       const int LOOPS = HZ/10;
+
+       apic_printk(APIC_VERBOSE, "calibrating APIC timer ...\n");
 
        /*
-        * The two version reads above should print the same
-        * numbers.  If the second one is different, then we
-        * poke at a non-APIC.
+        * Put whatever arbitrary (but long enough) timeout
+        * value into the APIC clock, we just want to get the
+        * counter running for calibration.
         */
-       if (reg1 != reg0)
-               return 0;
+       __setup_APIC_LVTT(1000000000);
 
        /*
-        * Check if the version looks reasonably.
+        * The timer chip counts down to zero. Let's wait
+        * for a wraparound to start exact measurement:
+        * (the current tick might have been already half done)
         */
-       reg1 = GET_APIC_VERSION(reg0);
-       if (reg1 == 0x00 || reg1 == 0xff)
-               return 0;
-       reg1 = get_maxlvt();
-       if (reg1 < 0x02 || reg1 == 0xff)
-               return 0;
+
+       wait_timer_tick();
 
        /*
-        * The ID register is read/write in a real APIC.
+        * We wrapped around just now. Let's start:
         */
-       reg0 = apic_read(APIC_ID);
-       apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
+       if (cpu_has_tsc)
+               rdtscll(t1);
+       tt1 = apic_read(APIC_TMCCT);
 
        /*
-        * The next two are just to see if we have sane values.
-        * They're only really relevant if we're in Virtual Wire
-        * compatibility mode, but most boxes are anymore.
+        * Let's wait LOOPS wraprounds:
         */
-       reg0 = apic_read(APIC_LVT0);
-       apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
-       reg1 = apic_read(APIC_LVT1);
-       apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
+       for (i = 0; i < LOOPS; i++)
+               wait_timer_tick();
 
-       return 1;
-}
+       tt2 = apic_read(APIC_TMCCT);
+       if (cpu_has_tsc)
+               rdtscll(t2);
 
-void __init sync_Arb_IDs(void)
-{
-       /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1
-          And not needed on AMD */
-       if (modern_apic())
-               return;
        /*
-        * Wait for idle.
+        * The APIC bus clock counter is 32 bits only, it
+        * might have overflown, but note that we use signed
+        * longs, thus no extra care needed.
+        *
+        * underflown to be exact, as the timer counts down ;)
         */
-       apic_wait_icr_idle();
 
-       apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
-       apic_write_around(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
-                               | APIC_DM_INIT);
+       result = (tt1-tt2)*APIC_DIVISOR/LOOPS;
+
+       if (cpu_has_tsc)
+               apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
+                       "%ld.%04ld MHz.\n",
+                       ((long)(t2-t1)/LOOPS)/(1000000/HZ),
+                       ((long)(t2-t1)/LOOPS)%(1000000/HZ));
+
+       apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
+               "%ld.%04ld MHz.\n",
+               result/(1000000/HZ),
+               result%(1000000/HZ));
+
+       return result;
 }
 
-extern void __error_in_apic_c (void);
+static unsigned int calibration_result;
 
-/*
- * An initial setup of the virtual wire mode.
- */
-void __init init_bsp_APIC(void)
+void __init setup_boot_APIC_clock(void)
 {
-       unsigned long value, ver;
+       unsigned long flags;
+       apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n");
+       using_apic_timer = 1;
+
+       local_irq_save(flags);
 
+       calibration_result = calibrate_APIC_clock();
        /*
-        * Don't do the setup now if we have a SMP BIOS as the
-        * through-I/O-APIC virtual wire mode might be active.
+        * Now set up the timer for real.
         */
-       if (smp_found_config || !cpu_has_apic)
-               return;
+       setup_APIC_timer(calibration_result);
+
+       local_irq_restore(flags);
+}
 
-       value = apic_read(APIC_LVR);
-       ver = GET_APIC_VERSION(value);
+void __devinit setup_secondary_APIC_clock(void)
+{
+       setup_APIC_timer(calibration_result);
+}
 
-       /*
-        * Do not trust the local APIC being empty at bootup.
-        */
-       clear_local_APIC();
+void disable_APIC_timer(void)
+{
+       if (using_apic_timer) {
+               unsigned long v;
 
-       /*
-        * Enable APIC.
-        */
-       value = apic_read(APIC_SPIV);
-       value &= ~APIC_VECTOR_MASK;
-       value |= APIC_SPIV_APIC_ENABLED;
-       
-       /* 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
-               value |= APIC_SPIV_FOCUS_DISABLED;
-       value |= SPURIOUS_APIC_VECTOR;
-       apic_write_around(APIC_SPIV, value);
+               v = apic_read(APIC_LVTT);
+               /*
+                * When an illegal vector value (0-15) is written to an LVT
+                * entry and delivery mode is Fixed, the APIC may signal an
+                * illegal vector error, with out regard to whether the mask
+                * bit is set or whether an interrupt is actually seen on
+                * input.
+                *
+                * Boot sequence might call this function when the LVTT has
+                * '0' vector value. So make sure vector field is set to
+                * valid value.
+                */
+               v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
+               apic_write_around(APIC_LVTT, v);
+       }
+}
 
-       /*
-        * Set up the virtual wire mode.
-        */
-       apic_write_around(APIC_LVT0, APIC_DM_EXTINT);
-       value = APIC_DM_NMI;
-       if (!APIC_INTEGRATED(ver))              /* 82489DX */
-               value |= APIC_LVT_LEVEL_TRIGGER;
-       apic_write_around(APIC_LVT1, value);
+void enable_APIC_timer(void)
+{
+       int cpu = smp_processor_id();
+
+       if (using_apic_timer && !cpu_isset(cpu, timer_bcast_ipi)) {
+               unsigned long v;
+
+               v = apic_read(APIC_LVTT);
+               apic_write_around(APIC_LVTT, v & ~APIC_LVT_MASKED);
+       }
 }
 
-void __devinit setup_local_APIC(void)
+void switch_APIC_timer_to_ipi(void *cpumask)
 {
-       unsigned long oldvalue, value, ver, maxlvt;
-       int i, j;
+       cpumask_t mask = *(cpumask_t *)cpumask;
+       int cpu = smp_processor_id();
 
-       /* Pound the ESR really hard over the head with a big hammer - mbligh */
-       if (esr_disable) {
-               apic_write(APIC_ESR, 0);
-               apic_write(APIC_ESR, 0);
-               apic_write(APIC_ESR, 0);
-               apic_write(APIC_ESR, 0);
+       if (cpu_isset(cpu, mask) &&
+           !cpu_isset(cpu, timer_bcast_ipi)) {
+               disable_APIC_timer();
+               cpu_set(cpu, timer_bcast_ipi);
        }
+}
+EXPORT_SYMBOL(switch_APIC_timer_to_ipi);
+
+void switch_ipi_to_APIC_timer(void *cpumask)
+{
+       cpumask_t mask = *(cpumask_t *)cpumask;
+       int cpu = smp_processor_id();
 
-       value = apic_read(APIC_LVR);
-       ver = GET_APIC_VERSION(value);
+       if (cpu_isset(cpu, mask) &&
+           cpu_isset(cpu, timer_bcast_ipi)) {
+               cpu_clear(cpu, timer_bcast_ipi);
+               enable_APIC_timer();
+       }
+}
+EXPORT_SYMBOL(switch_ipi_to_APIC_timer);
 
-       if ((SPURIOUS_APIC_VECTOR & 0x0f) != 0x0f)
-               __error_in_apic_c();
+/*
+ * Local timer interrupt handler. It does both profiling and
+ * process statistics/rescheduling.
+ */
+inline void smp_local_timer_interrupt(void)
+{
+       profile_tick(CPU_PROFILING);
+#ifdef CONFIG_SMP
+       update_process_times(user_mode_vm(get_irq_regs()));
+#endif
 
        /*
-        * Double-check whether this APIC is really registered.
+        * We take the 'long' return path, and there every subsystem
+        * grabs the apropriate locks (kernel lock/ irq lock).
+        *
+        * we might want to decouple profiling from the 'long path',
+        * and do the profiling totally in assembly.
+        *
+        * Currently this isn't too much of an issue (performance wise),
+        * we can take more than 100K local irqs per second on a 100 MHz P5.
         */
-       if (!apic_id_registered())
-               BUG();
+}
+
+/*
+ * Local APIC timer interrupt. This is the most natural way for doing
+ * local interrupts, but local timer interrupts can be emulated by
+ * broadcast interrupts too. [in case the hw doesn't support APIC timers]
+ *
+ * [ if a single-CPU system runs an SMP kernel then we call the local
+ *   interrupt as well. Thus we cannot inline the local irq ... ]
+ */
+
+fastcall void smp_apic_timer_interrupt(struct pt_regs *regs)
+{
+       struct pt_regs *old_regs = set_irq_regs(regs);
+       int cpu = smp_processor_id();
 
        /*
-        * Intel recommends to set DFR, LDR and TPR before enabling
-        * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
-        * document number 292116).  So here it goes...
+        * the NMI deadlock-detector uses this.
         */
-       init_apic_ldr();
+       per_cpu(irq_stat, cpu).apic_timer_irqs++;
 
        /*
-        * Set Task Priority to 'accept all'. We never change this
-        * later on.
+        * NOTE! We'd better ACK the irq immediately,
+        * because timer handling can be slow.
         */
-       value = apic_read(APIC_TASKPRI);
-       value &= ~APIC_TPRI_MASK;
-       apic_write_around(APIC_TASKPRI, value);
-
+       ack_APIC_irq();
        /*
-        * After a crash, we no longer service the interrupts and a pending
-        * interrupt from previous kernel might still have ISR bit set.
-        *
-        * Most probably by now CPU has serviced that pending interrupt and
-        * it might not have done the ack_APIC_irq() because it thought,
-        * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
-        * does not clear the ISR bit and cpu thinks it has already serivced
-        * the interrupt. Hence a vector might get locked. It was noticed
-        * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
+        * update_process_times() expects us to have done irq_enter().
+        * Besides, if we don't timer interrupts ignore the global
+        * interrupt lock, which is the WrongThing (tm) to do.
         */
-       for (i = APIC_ISR_NR - 1; i >= 0; i--) {
-               value = apic_read(APIC_ISR + i*0x10);
-               for (j = 31; j >= 0; j--) {
-                       if (value & (1<<j))
-                               ack_APIC_irq();
-               }
-       }
+       exit_idle();
+       irq_enter();
+       smp_local_timer_interrupt();
+       irq_exit();
+       set_irq_regs(old_regs);
+}
 
-       /*
-        * Now that we are all set up, enable the APIC
-        */
-       value = apic_read(APIC_SPIV);
-       value &= ~APIC_VECTOR_MASK;
-       /*
-        * Enable APIC
-        */
-       value |= APIC_SPIV_APIC_ENABLED;
+#ifndef CONFIG_SMP
+static void up_apic_timer_interrupt_call(void)
+{
+       int cpu = smp_processor_id();
 
        /*
-        * Some unknown Intel IO/APIC (or APIC) errata is biting us with
-        * certain networking cards. If high frequency interrupts are
-        * happening on a particular IOAPIC pin, plus the IOAPIC routing
-        * entry is masked/unmasked at a high rate as well then sooner or
-        * later IOAPIC line gets 'stuck', no more interrupts are received
-        * from the device. If focus CPU is disabled then the hang goes
-        * away, oh well :-(
-        *
-        * [ This bug can be reproduced easily with a level-triggered
-        *   PCI Ne2000 networking cards and PII/PIII processors, dual
-        *   BX chipset. ]
-        */
-       /*
-        * Actually disabling the focus CPU check just makes the hang less
-        * frequent as it makes the interrupt distributon model be more
-        * like LRU than MRU (the short-term load is more even across CPUs).
-        * See also the comment in end_level_ioapic_irq().  --macro
+        * the NMI deadlock-detector uses this.
         */
-#if 1
-       /* Enable focus processor (bit==0) */
-       value &= ~APIC_SPIV_FOCUS_DISABLED;
+       per_cpu(irq_stat, cpu).apic_timer_irqs++;
+
+       smp_local_timer_interrupt();
+}
+#endif
+
+void smp_send_timer_broadcast_ipi(void)
+{
+       cpumask_t mask;
+
+       cpus_and(mask, cpu_online_map, timer_bcast_ipi);
+       if (!cpus_empty(mask)) {
+#ifdef CONFIG_SMP
+               send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
 #else
-       /* Disable focus processor (bit==1) */
-       value |= APIC_SPIV_FOCUS_DISABLED;
+               /*
+                * We can directly call the apic timer interrupt handler
+                * in UP case. Minus all irq related functions
+                */
+               up_apic_timer_interrupt_call();
 #endif
-       /*
-        * Set spurious IRQ vector
-        */
-       value |= SPURIOUS_APIC_VECTOR;
-       apic_write_around(APIC_SPIV, value);
+       }
+}
+
+int setup_profiling_timer(unsigned int multiplier)
+{
+       return -EINVAL;
+}
+
+/*
+ * Local APIC start and shutdown
+ */
+
+/**
+ * clear_local_APIC - shutdown the local APIC
+ *
+ * This is called, when a CPU is disabled and before rebooting, so the state of
+ * the local APIC has no dangling leftovers. Also used to cleanout any BIOS
+ * leftovers during boot.
+ */
+void clear_local_APIC(void)
+{
+       int maxlvt = lapic_get_maxlvt();
+       unsigned long v;
 
        /*
-        * Set up LVT0, LVT1:
-        *
-        * set up through-local-APIC on the BP's LINT0. This is not
-        * strictly necessery in pure symmetric-IO mode, but sometimes
-        * we delegate interrupts to the 8259A.
+        * Masking an LVT entry can trigger a local APIC error
+        * if the vector is zero. Mask LVTERR first to prevent this.
         */
+       if (maxlvt >= 3) {
+               v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
+               apic_write_around(APIC_LVTERR, v | APIC_LVT_MASKED);
+       }
        /*
-        * TODO: set up through-local-APIC from through-I/O-APIC? --macro
+        * Careful: we have to set masks only first to deassert
+        * any level-triggered sources.
         */
-       value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
-       if (!smp_processor_id() && (pic_mode || !value)) {
-               value = APIC_DM_EXTINT;
-               apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
-                               smp_processor_id());
-       } else {
-               value = APIC_DM_EXTINT | APIC_LVT_MASKED;
-               apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
-                               smp_processor_id());
+       v = apic_read(APIC_LVTT);
+       apic_write_around(APIC_LVTT, v | APIC_LVT_MASKED);
+       v = apic_read(APIC_LVT0);
+       apic_write_around(APIC_LVT0, v | APIC_LVT_MASKED);
+       v = apic_read(APIC_LVT1);
+       apic_write_around(APIC_LVT1, v | APIC_LVT_MASKED);
+       if (maxlvt >= 4) {
+               v = apic_read(APIC_LVTPC);
+               apic_write_around(APIC_LVTPC, v | APIC_LVT_MASKED);
        }
-       apic_write_around(APIC_LVT0, value);
 
+       /* lets not touch this if we didn't frob it */
+#ifdef CONFIG_X86_MCE_P4THERMAL
+       if (maxlvt >= 5) {
+               v = apic_read(APIC_LVTTHMR);
+               apic_write_around(APIC_LVTTHMR, v | APIC_LVT_MASKED);
+       }
+#endif
        /*
-        * only the BP should see the LINT1 NMI signal, obviously.
+        * Clean APIC state for other OSs:
         */
-       if (!smp_processor_id())
-               value = APIC_DM_NMI;
-       else
-               value = APIC_DM_NMI | APIC_LVT_MASKED;
-       if (!APIC_INTEGRATED(ver))              /* 82489DX */
-               value |= APIC_LVT_LEVEL_TRIGGER;
-       apic_write_around(APIC_LVT1, value);
-
-       if (APIC_INTEGRATED(ver) && !esr_disable) {             /* !82489DX */
-               maxlvt = get_maxlvt();
-               if (maxlvt > 3)         /* Due to the Pentium erratum 3AP. */
-                       apic_write(APIC_ESR, 0);
-               oldvalue = apic_read(APIC_ESR);
+       apic_write_around(APIC_LVTT, APIC_LVT_MASKED);
+       apic_write_around(APIC_LVT0, APIC_LVT_MASKED);
+       apic_write_around(APIC_LVT1, APIC_LVT_MASKED);
+       if (maxlvt >= 3)
+               apic_write_around(APIC_LVTERR, APIC_LVT_MASKED);
+       if (maxlvt >= 4)
+               apic_write_around(APIC_LVTPC, APIC_LVT_MASKED);
 
-               value = ERROR_APIC_VECTOR;      // enables sending errors
-               apic_write_around(APIC_LVTERR, value);
-               /*
-                * spec says clear errors after enabling vector.
-                */
+#ifdef CONFIG_X86_MCE_P4THERMAL
+       if (maxlvt >= 5)
+               apic_write_around(APIC_LVTTHMR, APIC_LVT_MASKED);
+#endif
+       /* Integrated APIC (!82489DX) ? */
+       if (lapic_is_integrated()) {
                if (maxlvt > 3)
+                       /* Clear ESR due to Pentium errata 3AP and 11AP */
                        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 {
-               if (esr_disable)        
-                       /* 
-                        * Something untraceble 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("Leaving ESR disabled.\n");
-               else 
-                       printk("No ESR for 82489DX.\n");
+               apic_read(APIC_ESR);
        }
+}
 
-       setup_apic_nmi_watchdog(NULL);
-       apic_pm_activate();
+/**
+ * disable_local_APIC - clear and disable the local APIC
+ */
+void disable_local_APIC(void)
+{
+       unsigned long value;
+
+       clear_local_APIC();
+
+       /*
+        * Disable APIC (implies clearing of registers
+        * for 82489DX!).
+        */
+       value = apic_read(APIC_SPIV);
+       value &= ~APIC_SPIV_APIC_ENABLED;
+       apic_write_around(APIC_SPIV, value);
+
+       /*
+        * 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);
+       }
 }
 
 /*
- * 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
+ * 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)
@@ -625,168 +631,296 @@ void lapic_shutdown(void)
        local_irq_restore(flags);
 }
 
-#ifdef CONFIG_PM
-
-static struct {
-       int active;
-       /* r/w apic fields */
-       unsigned int apic_id;
-       unsigned int apic_taskpri;
-       unsigned int apic_ldr;
-       unsigned int apic_dfr;
-       unsigned int apic_spiv;
-       unsigned int apic_lvtt;
-       unsigned int apic_lvtpc;
-       unsigned int apic_lvt0;
-       unsigned int apic_lvt1;
-       unsigned int apic_lvterr;
-       unsigned int apic_tmict;
-       unsigned int apic_tdcr;
-       unsigned int apic_thmr;
-} apic_pm_state;
-
-static int lapic_suspend(struct sys_device *dev, pm_message_t state)
+/*
+ * This is to verify that we're looking at a real local APIC.
+ * Check these against your board if the CPUs aren't getting
+ * started for no apparent reason.
+ */
+int __init verify_local_APIC(void)
 {
-       unsigned long flags;
-       int maxlvt;
+       unsigned int reg0, reg1;
 
-       if (!apic_pm_state.active)
+       /*
+        * The version register is read-only in a real APIC.
+        */
+       reg0 = apic_read(APIC_LVR);
+       apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
+       apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
+       reg1 = apic_read(APIC_LVR);
+       apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);
+
+       /*
+        * The two version reads above should print the same
+        * numbers.  If the second one is different, then we
+        * poke at a non-APIC.
+        */
+       if (reg1 != reg0)
                return 0;
 
-       maxlvt = get_maxlvt();
+       /*
+        * Check if the version looks reasonably.
+        */
+       reg1 = GET_APIC_VERSION(reg0);
+       if (reg1 == 0x00 || reg1 == 0xff)
+               return 0;
+       reg1 = lapic_get_maxlvt();
+       if (reg1 < 0x02 || reg1 == 0xff)
+               return 0;
 
-       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);
-       apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
-       apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
-       if (maxlvt >= 4)
-               apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
-       apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
-       apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
-       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_P4THERMAL
-       if (maxlvt >= 5)
-               apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
-#endif
-       
-       local_irq_save(flags);
-       disable_local_APIC();
-       local_irq_restore(flags);
-       return 0;
+       /*
+        * The ID register is read/write in a real APIC.
+        */
+       reg0 = apic_read(APIC_ID);
+       apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
+
+       /*
+        * The next two are just to see if we have sane values.
+        * They're only really relevant if we're in Virtual Wire
+        * compatibility mode, but most boxes are anymore.
+        */
+       reg0 = apic_read(APIC_LVT0);
+       apic_printk(APIC_DEBUG, "Getting LVT0: %x\n", reg0);
+       reg1 = apic_read(APIC_LVT1);
+       apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);
+
+       return 1;
 }
 
-static int lapic_resume(struct sys_device *dev)
+/**
+ * sync_Arb_IDs - synchronize APIC bus arbitration IDs
+ */
+void __init sync_Arb_IDs(void)
 {
-       unsigned int l, h;
-       unsigned long flags;
-       int maxlvt;
+       /*
+        * Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 And not
+        * needed on AMD.
+        */
+       if (modern_apic())
+               return;
+       /*
+        * Wait for idle.
+        */
+       apic_wait_icr_idle();
 
-       if (!apic_pm_state.active)
-               return 0;
+       apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
+       apic_write_around(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
+                               | APIC_DM_INIT);
+}
 
-       maxlvt = get_maxlvt();
+/*
+ * An initial setup of the virtual wire mode.
+ */
+void __init init_bsp_APIC(void)
+{
+       unsigned long value;
 
-       local_irq_save(flags);
+       /*
+        * Don't do the setup now if we have a SMP BIOS as the
+        * through-I/O-APIC virtual wire mode might be active.
+        */
+       if (smp_found_config || !cpu_has_apic)
+               return;
 
        /*
-        * 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!
+        * Do not trust the local APIC being empty at bootup.
         */
-       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);
+       clear_local_APIC();
 
-       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);
-       apic_write(APIC_LDR, apic_pm_state.apic_ldr);
-       apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
-       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_P4THERMAL
-       if (maxlvt >= 5)
-               apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
-#endif
-       if (maxlvt >= 4)
-               apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
-       apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
-       apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
-       apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
-       apic_write(APIC_ESR, 0);
-       apic_read(APIC_ESR);
-       apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
-       apic_write(APIC_ESR, 0);
-       apic_read(APIC_ESR);
-       local_irq_restore(flags);
-       return 0;
+       /*
+        * Enable APIC.
+        */
+       value = apic_read(APIC_SPIV);
+       value &= ~APIC_VECTOR_MASK;
+       value |= APIC_SPIV_APIC_ENABLED;
+
+       /* 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
+               value |= APIC_SPIV_FOCUS_DISABLED;
+       value |= SPURIOUS_APIC_VECTOR;
+       apic_write_around(APIC_SPIV, value);
+
+       /*
+        * Set up the virtual wire mode.
+        */
+       apic_write_around(APIC_LVT0, APIC_DM_EXTINT);
+       value = APIC_DM_NMI;
+       if (!lapic_is_integrated())             /* 82489DX */
+               value |= APIC_LVT_LEVEL_TRIGGER;
+       apic_write_around(APIC_LVT1, value);
 }
 
-/*
- * This device has no shutdown method - fully functioning local APICs
- * are needed on every CPU up until machine_halt/restart/poweroff.
+/**
+ * setup_local_APIC - setup the local APIC
  */
+void __devinit setup_local_APIC(void)
+{
+       unsigned long oldvalue, value, maxlvt, integrated;
+       int i, j;
 
-static struct sysdev_class lapic_sysclass = {
-       set_kset_name("lapic"),
-       .resume         = lapic_resume,
-       .suspend        = lapic_suspend,
-};
+       /* Pound the ESR really hard over the head with a big hammer - mbligh */
+       if (esr_disable) {
+               apic_write(APIC_ESR, 0);
+               apic_write(APIC_ESR, 0);
+               apic_write(APIC_ESR, 0);
+               apic_write(APIC_ESR, 0);
+       }
 
-static struct sys_device device_lapic = {
-       .id     = 0,
-       .cls    = &lapic_sysclass,
-};
+       integrated = lapic_is_integrated();
 
-static void __devinit apic_pm_activate(void)
-{
-       apic_pm_state.active = 1;
-}
+       /*
+        * Double-check whether this APIC is really registered.
+        */
+       if (!apic_id_registered())
+               BUG();
 
-static int __init init_lapic_sysfs(void)
-{
-       int error;
+       /*
+        * Intel recommends to set DFR, LDR and TPR before enabling
+        * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
+        * document number 292116).  So here it goes...
+        */
+       init_apic_ldr();
 
-       if (!cpu_has_apic)
-               return 0;
-       /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
+       /*
+        * Set Task Priority to 'accept all'. We never change this
+        * later on.
+        */
+       value = apic_read(APIC_TASKPRI);
+       value &= ~APIC_TPRI_MASK;
+       apic_write_around(APIC_TASKPRI, value);
 
-       error = sysdev_class_register(&lapic_sysclass);
-       if (!error)
-               error = sysdev_register(&device_lapic);
-       return error;
-}
-device_initcall(init_lapic_sysfs);
+       /*
+        * After a crash, we no longer service the interrupts and a pending
+        * interrupt from previous kernel might still have ISR bit set.
+        *
+        * Most probably by now CPU has serviced that pending interrupt and
+        * it might not have done the ack_APIC_irq() because it thought,
+        * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
+        * does not clear the ISR bit and cpu thinks it has already serivced
+        * the interrupt. Hence a vector might get locked. It was noticed
+        * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
+        */
+       for (i = APIC_ISR_NR - 1; i >= 0; i--) {
+               value = apic_read(APIC_ISR + i*0x10);
+               for (j = 31; j >= 0; j--) {
+                       if (value & (1<<j))
+                               ack_APIC_irq();
+               }
+       }
 
-#else  /* CONFIG_PM */
+       /*
+        * Now that we are all set up, enable the APIC
+        */
+       value = apic_read(APIC_SPIV);
+       value &= ~APIC_VECTOR_MASK;
+       /*
+        * Enable APIC
+        */
+       value |= APIC_SPIV_APIC_ENABLED;
 
-static void apic_pm_activate(void) { }
+       /*
+        * Some unknown Intel IO/APIC (or APIC) errata is biting us with
+        * certain networking cards. If high frequency interrupts are
+        * happening on a particular IOAPIC pin, plus the IOAPIC routing
+        * entry is masked/unmasked at a high rate as well then sooner or
+        * later IOAPIC line gets 'stuck', no more interrupts are received
+        * from the device. If focus CPU is disabled then the hang goes
+        * away, oh well :-(
+        *
+        * [ This bug can be reproduced easily with a level-triggered
+        *   PCI Ne2000 networking cards and PII/PIII processors, dual
+        *   BX chipset. ]
+        */
+       /*
+        * Actually disabling the focus CPU check just makes the hang less
+        * frequent as it makes the interrupt distributon model be more
+        * like LRU than MRU (the short-term load is more even across CPUs).
+        * See also the comment in end_level_ioapic_irq().  --macro
+        */
 
-#endif /* CONFIG_PM */
+       /* Enable focus processor (bit==0) */
+       value &= ~APIC_SPIV_FOCUS_DISABLED;
 
-/*
- * Detect and enable local APICs on non-SMP boards.
- * Original code written by Keir Fraser.
- */
+       /*
+        * Set spurious IRQ vector
+        */
+       value |= SPURIOUS_APIC_VECTOR;
+       apic_write_around(APIC_SPIV, value);
+
+       /*
+        * Set up LVT0, LVT1:
+        *
+        * set up through-local-APIC on the BP's LINT0. This is not
+        * strictly necessery in pure symmetric-IO mode, but sometimes
+        * we delegate interrupts to the 8259A.
+        */
+       /*
+        * TODO: set up through-local-APIC from through-I/O-APIC? --macro
+        */
+       value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
+       if (!smp_processor_id() && (pic_mode || !value)) {
+               value = APIC_DM_EXTINT;
+               apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n",
+                               smp_processor_id());
+       } else {
+               value = APIC_DM_EXTINT | APIC_LVT_MASKED;
+               apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n",
+                               smp_processor_id());
+       }
+       apic_write_around(APIC_LVT0, value);
+
+       /*
+        * only the BP should see the LINT1 NMI signal, obviously.
+        */
+       if (!smp_processor_id())
+               value = APIC_DM_NMI;
+       else
+               value = APIC_DM_NMI | APIC_LVT_MASKED;
+       if (!integrated)                /* 82489DX */
+               value |= APIC_LVT_LEVEL_TRIGGER;
+       apic_write_around(APIC_LVT1, value);
+
+       if (integrated && !esr_disable) {               /* !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_around(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 {
+               if (esr_disable)
+                       /*
+                        * Something untraceble 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");
+               else
+                       printk(KERN_INFO "No ESR for 82489DX.\n");
+       }
 
-static int __init apic_set_verbosity(char *str)
-{
-       if (strcmp("debug", str) == 0)
-               apic_verbosity = APIC_DEBUG;
-       else if (strcmp("verbose", str) == 0)
-               apic_verbosity = APIC_VERBOSE;
-       return 1;
+       setup_apic_nmi_watchdog(NULL);
+       apic_pm_activate();
 }
 
-__setup("apic=", apic_set_verbosity);
-
+/*
+ * Detect and initialize APIC
+ */
 static int __init detect_init_APIC (void)
 {
        u32 h, l, features;
@@ -798,7 +932,7 @@ static int __init detect_init_APIC (void)
        switch (boot_cpu_data.x86_vendor) {
        case X86_VENDOR_AMD:
                if ((boot_cpu_data.x86 == 6 && boot_cpu_data.x86_model > 1) ||
-                   (boot_cpu_data.x86 == 15))      
+                   (boot_cpu_data.x86 == 15))
                        break;
                goto no_apic;
        case X86_VENDOR_INTEL:
@@ -812,23 +946,23 @@ static int __init detect_init_APIC (void)
 
        if (!cpu_has_apic) {
                /*
-                * Over-ride BIOS and try to enable the local
-                * APIC only if "lapic" specified.
+                * Over-ride BIOS and try to enable the local APIC only if
+                * "lapic" specified.
                 */
                if (enable_local_apic <= 0) {
-                       printk("Local APIC disabled by BIOS -- "
+                       printk(KERN_INFO "Local APIC disabled by BIOS -- "
                               "you can enable it with \"lapic\"\n");
                        return -1;
                }
                /*
-                * Some BIOSes disable the local APIC in the
-                * APIC_BASE MSR. This can only be done in
-                * software for Intel P6 or later and AMD K7
-                * (Model > 1) or later.
+                * Some BIOSes disable the local APIC in the APIC_BASE
+                * MSR. This can only be done in software for Intel P6 or later
+                * and AMD K7 (Model > 1) or later.
                 */
                rdmsr(MSR_IA32_APICBASE, l, h);
                if (!(l & MSR_IA32_APICBASE_ENABLE)) {
-                       printk("Local APIC disabled by BIOS -- reenabling.\n");
+                       printk(KERN_INFO
+                              "Local APIC disabled by BIOS -- reenabling.\n");
                        l &= ~MSR_IA32_APICBASE_BASE;
                        l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
                        wrmsr(MSR_IA32_APICBASE, l, h);
@@ -841,7 +975,7 @@ static int __init detect_init_APIC (void)
         */
        features = cpuid_edx(1);
        if (!(features & (1 << X86_FEATURE_APIC))) {
-               printk("Could not enable APIC!\n");
+               printk(KERN_WARNING "Could not enable APIC!\n");
                return -1;
        }
        set_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
@@ -849,457 +983,167 @@ static int __init detect_init_APIC (void)
 
        /* The BIOS may have set up the APIC at some other address */
        rdmsr(MSR_IA32_APICBASE, l, h);
-       if (l & MSR_IA32_APICBASE_ENABLE)
-               mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
-
-       if (nmi_watchdog != NMI_NONE)
-               nmi_watchdog = NMI_LOCAL_APIC;
-
-       printk("Found and enabled local APIC!\n");
-
-       apic_pm_activate();
-
-       return 0;
-
-no_apic:
-       printk("No local APIC present or hardware disabled\n");
-       return -1;
-}
-
-void __init init_apic_mappings(void)
-{
-       unsigned long apic_phys;
-
-       /*
-        * If no local APIC can be found then set up a fake all
-        * zeroes page to simulate the local APIC and another
-        * one for the IO-APIC.
-        */
-       if (!smp_found_config && detect_init_APIC()) {
-               apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
-               apic_phys = __pa(apic_phys);
-       } else
-               apic_phys = mp_lapic_addr;
-
-       set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
-       printk(KERN_DEBUG "mapped APIC to %08lx (%08lx)\n", APIC_BASE,
-              apic_phys);
-
-       /*
-        * Fetch the APIC ID of the BSP in case we have a
-        * default configuration (or the MP table is broken).
-        */
-       if (boot_cpu_physical_apicid == -1U)
-               boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
-
-#ifdef CONFIG_X86_IO_APIC
-       {
-               unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
-               int i;
-
-               for (i = 0; i < nr_ioapics; i++) {
-                       if (smp_found_config) {
-                               ioapic_phys = mp_ioapics[i].mpc_apicaddr;
-                               if (!ioapic_phys) {
-                                       printk(KERN_ERR
-                                              "WARNING: bogus zero IO-APIC "
-                                              "address found in MPTABLE, "
-                                              "disabling IO/APIC support!\n");
-                                       smp_found_config = 0;
-                                       skip_ioapic_setup = 1;
-                                       goto fake_ioapic_page;
-                               }
-                       } else {
-fake_ioapic_page:
-                               ioapic_phys = (unsigned long)
-                                             alloc_bootmem_pages(PAGE_SIZE);
-                               ioapic_phys = __pa(ioapic_phys);
-                       }
-                       set_fixmap_nocache(idx, ioapic_phys);
-                       printk(KERN_DEBUG "mapped IOAPIC to %08lx (%08lx)\n",
-                              __fix_to_virt(idx), ioapic_phys);
-                       idx++;
-               }
-       }
-#endif
-}
-
-/*
- * This part sets up the APIC 32 bit clock in LVTT1, with HZ interrupts
- * per second. We assume that the caller has already set up the local
- * APIC.
- *
- * The APIC timer is not exactly sync with the external timer chip, it
- * closely follows bus clocks.
- */
-
-/*
- * The timer chip is already set up at HZ interrupts per second here,
- * but we do not accept timer interrupts yet. We only allow the BP
- * to calibrate.
- */
-static unsigned int __devinit get_8254_timer_count(void)
-{
-       unsigned long flags;
-
-       unsigned int count;
-
-       spin_lock_irqsave(&i8253_lock, flags);
-
-       outb_p(0x00, PIT_MODE);
-       count = inb_p(PIT_CH0);
-       count |= inb_p(PIT_CH0) << 8;
-
-       spin_unlock_irqrestore(&i8253_lock, flags);
-
-       return count;
-}
-
-/* next tick in 8254 can be caught by catching timer wraparound */
-static void __devinit wait_8254_wraparound(void)
-{
-       unsigned int curr_count, prev_count;
-
-       curr_count = get_8254_timer_count();
-       do {
-               prev_count = curr_count;
-               curr_count = get_8254_timer_count();
-
-               /* workaround for broken Mercury/Neptune */
-               if (prev_count >= curr_count + 0x100)
-                       curr_count = get_8254_timer_count();
-
-       } while (prev_count >= curr_count);
-}
-
-/*
- * Default initialization for 8254 timers. If we use other timers like HPET,
- * we override this later
- */
-void (*wait_timer_tick)(void) __devinitdata = wait_8254_wraparound;
-
-/*
- * 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
- * value, second time for real. The other (noncalibrating) CPUs
- * call this function only once, with the real, calibrated value.
- *
- * We do reads before writes even if unnecessary, to get around the
- * P5 APIC double write bug.
- */
-
-#define APIC_DIVISOR 16
-
-static void __setup_APIC_LVTT(unsigned int clocks)
-{
-       unsigned int lvtt_value, tmp_value, ver;
-       int cpu = smp_processor_id();
-
-       ver = GET_APIC_VERSION(apic_read(APIC_LVR));
-       lvtt_value = APIC_LVT_TIMER_PERIODIC | LOCAL_TIMER_VECTOR;
-       if (!APIC_INTEGRATED(ver))
-               lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
-
-       if (cpu_isset(cpu, timer_bcast_ipi))
-               lvtt_value |= APIC_LVT_MASKED;
-
-       apic_write_around(APIC_LVTT, lvtt_value);
-
-       /*
-        * Divide PICLK by 16
-        */
-       tmp_value = apic_read(APIC_TDCR);
-       apic_write_around(APIC_TDCR, (tmp_value
-                               & ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
-                               | APIC_TDR_DIV_16);
-
-       apic_write_around(APIC_TMICT, clocks/APIC_DIVISOR);
-}
-
-static void __devinit setup_APIC_timer(unsigned int clocks)
-{
-       unsigned long flags;
-
-       local_irq_save(flags);
-
-       /*
-        * Wait for IRQ0's slice:
-        */
-       wait_timer_tick();
-
-       __setup_APIC_LVTT(clocks);
-
-       local_irq_restore(flags);
-}
-
-/*
- * In this function we calibrate APIC bus clocks to the external
- * timer. Unfortunately we cannot use jiffies and the timer irq
- * to calibrate, since some later bootup code depends on getting
- * the first irq? Ugh.
- *
- * We want to do the calibration only once since we
- * want to have local timer irqs syncron. CPUs connected
- * by the same APIC bus have the very same bus frequency.
- * And we want to have irqs off anyways, no accidental
- * APIC irq that way.
- */
-
-static int __init calibrate_APIC_clock(void)
-{
-       unsigned long long t1 = 0, t2 = 0;
-       long tt1, tt2;
-       long result;
-       int i;
-       const int LOOPS = HZ/10;
-
-       apic_printk(APIC_VERBOSE, "calibrating APIC timer ...\n");
-
-       /*
-        * Put whatever arbitrary (but long enough) timeout
-        * value into the APIC clock, we just want to get the
-        * counter running for calibration.
-        */
-       __setup_APIC_LVTT(1000000000);
-
-       /*
-        * The timer chip counts down to zero. Let's wait
-        * for a wraparound to start exact measurement:
-        * (the current tick might have been already half done)
-        */
-
-       wait_timer_tick();
-
-       /*
-        * We wrapped around just now. Let's start:
-        */
-       if (cpu_has_tsc)
-               rdtscll(t1);
-       tt1 = apic_read(APIC_TMCCT);
-
-       /*
-        * Let's wait LOOPS wraprounds:
-        */
-       for (i = 0; i < LOOPS; i++)
-               wait_timer_tick();
-
-       tt2 = apic_read(APIC_TMCCT);
-       if (cpu_has_tsc)
-               rdtscll(t2);
-
-       /*
-        * The APIC bus clock counter is 32 bits only, it
-        * might have overflown, but note that we use signed
-        * longs, thus no extra care needed.
-        *
-        * underflown to be exact, as the timer counts down ;)
-        */
+       if (l & MSR_IA32_APICBASE_ENABLE)
+               mp_lapic_addr = l & MSR_IA32_APICBASE_BASE;
 
-       result = (tt1-tt2)*APIC_DIVISOR/LOOPS;
+       if (nmi_watchdog != NMI_NONE)
+               nmi_watchdog = NMI_LOCAL_APIC;
 
-       if (cpu_has_tsc)
-               apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
-                       "%ld.%04ld MHz.\n",
-                       ((long)(t2-t1)/LOOPS)/(1000000/HZ),
-                       ((long)(t2-t1)/LOOPS)%(1000000/HZ));
+       printk(KERN_INFO "Found and enabled local APIC!\n");
 
-       apic_printk(APIC_VERBOSE, "..... host bus clock speed is "
-               "%ld.%04ld MHz.\n",
-               result/(1000000/HZ),
-               result%(1000000/HZ));
+       apic_pm_activate();
 
-       return result;
-}
+       return 0;
 
-static unsigned int calibration_result;
+no_apic:
+       printk(KERN_INFO "No local APIC present or hardware disabled\n");
+       return -1;
+}
 
-void __init setup_boot_APIC_clock(void)
+/**
+ * init_apic_mappings - initialize APIC mappings
+ */
+void __init init_apic_mappings(void)
 {
-       unsigned long flags;
-       apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n");
-       using_apic_timer = 1;
-
-       local_irq_save(flags);
+       unsigned long apic_phys;
 
-       calibration_result = calibrate_APIC_clock();
        /*
-        * Now set up the timer for real.
+        * If no local APIC can be found then set up a fake all
+        * zeroes page to simulate the local APIC and another
+        * one for the IO-APIC.
         */
-       setup_APIC_timer(calibration_result);
+       if (!smp_found_config && detect_init_APIC()) {
+               apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
+               apic_phys = __pa(apic_phys);
+       } else
+               apic_phys = mp_lapic_addr;
 
-       local_irq_restore(flags);
-}
+       set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
+       printk(KERN_DEBUG "mapped APIC to %08lx (%08lx)\n", APIC_BASE,
+              apic_phys);
 
-void __devinit setup_secondary_APIC_clock(void)
-{
-       setup_APIC_timer(calibration_result);
-}
+       /*
+        * Fetch the APIC ID of the BSP in case we have a
+        * default configuration (or the MP table is broken).
+        */
+       if (boot_cpu_physical_apicid == -1U)
+               boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
 
-void disable_APIC_timer(void)
-{
-       if (using_apic_timer) {
-               unsigned long v;
+#ifdef CONFIG_X86_IO_APIC
+       {
+               unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
+               int i;
 
-               v = apic_read(APIC_LVTT);
-               /*
-                * When an illegal vector value (0-15) is written to an LVT
-                * entry and delivery mode is Fixed, the APIC may signal an
-                * illegal vector error, with out regard to whether the mask
-                * bit is set or whether an interrupt is actually seen on input.
-                *
-                * Boot sequence might call this function when the LVTT has
-                * '0' vector value. So make sure vector field is set to
-                * valid value.
-                */
-               v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
-               apic_write_around(APIC_LVTT, v);
+               for (i = 0; i < nr_ioapics; i++) {
+                       if (smp_found_config) {
+                               ioapic_phys = mp_ioapics[i].mpc_apicaddr;
+                               if (!ioapic_phys) {
+                                       printk(KERN_ERR
+                                              "WARNING: bogus zero IO-APIC "
+                                              "address found in MPTABLE, "
+                                              "disabling IO/APIC support!\n");
+                                       smp_found_config = 0;
+                                       skip_ioapic_setup = 1;
+                                       goto fake_ioapic_page;
+                               }
+                       } else {
+fake_ioapic_page:
+                               ioapic_phys = (unsigned long)
+                                             alloc_bootmem_pages(PAGE_SIZE);
+                               ioapic_phys = __pa(ioapic_phys);
+                       }
+                       set_fixmap_nocache(idx, ioapic_phys);
+                       printk(KERN_DEBUG "mapped IOAPIC to %08lx (%08lx)\n",
+                              __fix_to_virt(idx), ioapic_phys);
+                       idx++;
+               }
        }
+#endif
 }
 
-void enable_APIC_timer(void)
+/*
+ * This initializes the IO-APIC and APIC hardware if this is
+ * a UP kernel.
+ */
+int __init APIC_init_uniprocessor (void)
 {
-       int cpu = smp_processor_id();
-
-       if (using_apic_timer &&
-           !cpu_isset(cpu, timer_bcast_ipi)) {
-               unsigned long v;
-
-               v = apic_read(APIC_LVTT);
-               apic_write_around(APIC_LVTT, v & ~APIC_LVT_MASKED);
-       }
-}
+       if (enable_local_apic < 0)
+               clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
 
-void switch_APIC_timer_to_ipi(void *cpumask)
-{
-       cpumask_t mask = *(cpumask_t *)cpumask;
-       int cpu = smp_processor_id();
+       if (!smp_found_config && !cpu_has_apic)
+               return -1;
 
-       if (cpu_isset(cpu, mask) &&
-           !cpu_isset(cpu, timer_bcast_ipi)) {
-               disable_APIC_timer();
-               cpu_set(cpu, timer_bcast_ipi);
+       /*
+        * Complain if the BIOS pretends there is one.
+        */
+       if (!cpu_has_apic &&
+           APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
+               printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
+                      boot_cpu_physical_apicid);
+               clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
+               return -1;
        }
-}
-EXPORT_SYMBOL(switch_APIC_timer_to_ipi);
 
-void switch_ipi_to_APIC_timer(void *cpumask)
-{
-       cpumask_t mask = *(cpumask_t *)cpumask;
-       int cpu = smp_processor_id();
+       verify_local_APIC();
 
-       if (cpu_isset(cpu, mask) &&
-           cpu_isset(cpu, timer_bcast_ipi)) {
-               cpu_clear(cpu, timer_bcast_ipi);
-               enable_APIC_timer();
-       }
-}
-EXPORT_SYMBOL(switch_ipi_to_APIC_timer);
+       connect_bsp_APIC();
 
-#undef APIC_DIVISOR
+       /*
+        * Hack: In case of kdump, after a crash, kernel might be booting
+        * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
+        * might be zero if read from MP tables. Get it from LAPIC.
+        */
+#ifdef CONFIG_CRASH_DUMP
+       boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
+#endif
+       phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid);
 
-/*
- * Local timer interrupt handler. It does both profiling and
- * process statistics/rescheduling.
- *
- * We do profiling in every local tick, statistics/rescheduling
- * happen only every 'profiling multiplier' ticks. The default
- * multiplier is 1 and it can be changed by writing the new multiplier
- * value into /proc/profile.
- */
+       setup_local_APIC();
 
-inline void smp_local_timer_interrupt(void)
-{
-       profile_tick(CPU_PROFILING);
-#ifdef CONFIG_SMP
-       update_process_times(user_mode_vm(get_irq_regs()));
+#ifdef CONFIG_X86_IO_APIC
+       if (smp_found_config)
+               if (!skip_ioapic_setup && nr_ioapics)
+                       setup_IO_APIC();
 #endif
+       setup_boot_clock();
 
-       /*
-        * We take the 'long' return path, and there every subsystem
-        * grabs the apropriate locks (kernel lock/ irq lock).
-        *
-        * we might want to decouple profiling from the 'long path',
-        * and do the profiling totally in assembly.
-        *
-        * Currently this isn't too much of an issue (performance wise),
-        * we can take more than 100K local irqs per second on a 100 MHz P5.
-        */
+       return 0;
 }
 
 /*
- * Local APIC timer interrupt. This is the most natural way for doing
- * local interrupts, but local timer interrupts can be emulated by
- * broadcast interrupts too. [in case the hw doesn't support APIC timers]
- *
- * [ if a single-CPU system runs an SMP kernel then we call the local
- *   interrupt as well. Thus we cannot inline the local irq ... ]
+ * APIC command line parameters
  */
-
-fastcall void smp_apic_timer_interrupt(struct pt_regs *regs)
-{
-       struct pt_regs *old_regs = set_irq_regs(regs);
-       int cpu = smp_processor_id();
-
-       /*
-        * the NMI deadlock-detector uses this.
-        */
-       per_cpu(irq_stat, cpu).apic_timer_irqs++;
-
-       /*
-        * NOTE! We'd better ACK the irq immediately,
-        * because timer handling can be slow.
-        */
-       ack_APIC_irq();
-       /*
-        * update_process_times() expects us to have done irq_enter().
-        * Besides, if we don't timer interrupts ignore the global
-        * interrupt lock, which is the WrongThing (tm) to do.
-        */
-       exit_idle();
-       irq_enter();
-       smp_local_timer_interrupt();
-       irq_exit();
-       set_irq_regs(old_regs);
-}
-
-#ifndef CONFIG_SMP
-static void up_apic_timer_interrupt_call(void)
+static int __init parse_lapic(char *arg)
 {
-       int cpu = smp_processor_id();
-
-       /*
-        * the NMI deadlock-detector uses this.
-        */
-       per_cpu(irq_stat, cpu).apic_timer_irqs++;
-
-       smp_local_timer_interrupt();
+       enable_local_apic = 1;
+       return 0;
 }
-#endif
+early_param("lapic", parse_lapic);
 
-void smp_send_timer_broadcast_ipi(void)
+static int __init parse_nolapic(char *arg)
 {
-       cpumask_t mask;
-
-       cpus_and(mask, cpu_online_map, timer_bcast_ipi);
-       if (!cpus_empty(mask)) {
-#ifdef CONFIG_SMP
-               send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
-#else
-               /*
-                * We can directly call the apic timer interrupt handler
-                * in UP case. Minus all irq related functions
-                */
-               up_apic_timer_interrupt_call();
-#endif
-       }
+       enable_local_apic = -1;
+       clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
+       return 0;
 }
+early_param("nolapic", parse_nolapic);
 
-int setup_profiling_timer(unsigned int multiplier)
+static int __init apic_set_verbosity(char *str)
 {
-       return -EINVAL;
+       if (strcmp("debug", str) == 0)
+               apic_verbosity = APIC_DEBUG;
+       else if (strcmp("verbose", str) == 0)
+               apic_verbosity = APIC_VERBOSE;
+       return 1;
 }
 
+__setup("apic=", apic_set_verbosity);
+
+
+/*
+ * Local APIC interrupts
+ */
+
 /*
  * This interrupt should _never_ happen with our APIC/SMP architecture
  */
@@ -1319,15 +1163,14 @@ fastcall void smp_spurious_interrupt(struct pt_regs *regs)
                ack_APIC_irq();
 
        /* see sw-dev-man vol 3, chapter 7.4.13.5 */
-       printk(KERN_INFO "spurious APIC interrupt on CPU#%d, should never happen.\n",
-                       smp_processor_id());
+       printk(KERN_INFO "spurious APIC interrupt on CPU#%d, "
+              "should never happen.\n", smp_processor_id());
        irq_exit();
 }
 
 /*
  * This interrupt should never happen with our APIC/SMP architecture
  */
-
 fastcall void smp_error_interrupt(struct pt_regs *regs)
 {
        unsigned long v, v1;
@@ -1352,69 +1195,261 @@ fastcall void smp_error_interrupt(struct pt_regs *regs)
           7: Illegal register address
        */
        printk (KERN_DEBUG "APIC error on CPU%d: %02lx(%02lx)\n",
-               smp_processor_id(), v , v1);
+               smp_processor_id(), v , v1);
        irq_exit();
 }
 
 /*
- * This initializes the IO-APIC and APIC hardware if this is
- * a UP kernel.
+ * Initialize APIC interrupts
  */
-int __init APIC_init_uniprocessor (void)
+void __init apic_intr_init(void)
 {
-       if (enable_local_apic < 0)
-               clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
+#ifdef CONFIG_SMP
+       smp_intr_init();
+#endif
+       /* self generated IPI for local APIC timer */
+       set_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
 
-       if (!smp_found_config && !cpu_has_apic)
-               return -1;
+       /* IPI vectors for APIC spurious and error interrupts */
+       set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
+       set_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
 
-       /*
-        * Complain if the BIOS pretends there is one.
-        */
-       if (!cpu_has_apic && APIC_INTEGRATED(apic_version[boot_cpu_physical_apicid])) {
-               printk(KERN_ERR "BIOS bug, local APIC #%d not detected!...\n",
-                       boot_cpu_physical_apicid);
-               clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
-               return -1;
+       /* thermal monitor LVT interrupt */
+#ifdef CONFIG_X86_MCE_P4THERMAL
+       set_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
+#endif
+}
+
+/**
+ * connect_bsp_APIC - attach the APIC to the interrupt system
+ */
+void __init connect_bsp_APIC(void)
+{
+       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);
        }
+       enable_apic_mode();
+}
 
-       verify_local_APIC();
+/**
+ * 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)
+{
+       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);
+       } else {
+               /* Go back to Virtual Wire compatibility mode */
+               unsigned long value;
 
-       connect_bsp_APIC();
+               /* For the spurious interrupt use vector F, and enable it */
+               value = apic_read(APIC_SPIV);
+               value &= ~APIC_VECTOR_MASK;
+               value |= APIC_SPIV_APIC_ENABLED;
+               value |= 0xf;
+               apic_write_around(APIC_SPIV, value);
 
-       /*
-        * Hack: In case of kdump, after a crash, kernel might be booting
-        * on a cpu with non-zero lapic id. But boot_cpu_physical_apicid
-        * might be zero if read from MP tables. Get it from LAPIC.
-        */
-#ifdef CONFIG_CRASH_DUMP
-       boot_cpu_physical_apicid = GET_APIC_ID(apic_read(APIC_ID));
-#endif
-       phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid);
+               if (!virt_wire_setup) {
+                       /*
+                        * For LVT0 make it edge triggered, active high,
+                        * external and enabled
+                        */
+                       value = apic_read(APIC_LVT0);
+                       value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
+                               APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
+                               APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED );
+                       value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
+                       value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
+                       apic_write_around(APIC_LVT0, value);
+               } else {
+                       /* Disable LVT0 */
+                       apic_write_around(APIC_LVT0, APIC_LVT_MASKED);
+               }
 
-       setup_local_APIC();
+               /*
+                * 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 |
+                       APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
+               value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
+               value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
+               apic_write_around(APIC_LVT1, value);
+       }
+}
 
-#ifdef CONFIG_X86_IO_APIC
-       if (smp_found_config)
-               if (!skip_ioapic_setup && nr_ioapics)
-                       setup_IO_APIC();
+/*
+ * Power management
+ */
+#ifdef CONFIG_PM
+
+static struct {
+       int active;
+       /* r/w apic fields */
+       unsigned int apic_id;
+       unsigned int apic_taskpri;
+       unsigned int apic_ldr;
+       unsigned int apic_dfr;
+       unsigned int apic_spiv;
+       unsigned int apic_lvtt;
+       unsigned int apic_lvtpc;
+       unsigned int apic_lvt0;
+       unsigned int apic_lvt1;
+       unsigned int apic_lvterr;
+       unsigned int apic_tmict;
+       unsigned int apic_tdcr;
+       unsigned int apic_thmr;
+} apic_pm_state;
+
+static int lapic_suspend(struct sys_device *dev, pm_message_t state)
+{
+       unsigned long flags;
+       int maxlvt;
+
+       if (!apic_pm_state.active)
+               return 0;
+
+       maxlvt = lapic_get_maxlvt();
+
+       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);
+       apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
+       apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
+       if (maxlvt >= 4)
+               apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
+       apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
+       apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
+       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_P4THERMAL
+       if (maxlvt >= 5)
+               apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
 #endif
-       setup_boot_clock();
 
+       local_irq_save(flags);
+       disable_local_APIC();
+       local_irq_restore(flags);
        return 0;
 }
 
-static int __init parse_lapic(char *arg)
+static int lapic_resume(struct sys_device *dev)
 {
-       lapic_enable();
+       unsigned int l, h;
+       unsigned long flags;
+       int maxlvt;
+
+       if (!apic_pm_state.active)
+               return 0;
+
+       maxlvt = lapic_get_maxlvt();
+
+       local_irq_save(flags);
+
+       /*
+        * 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);
+       apic_write(APIC_LDR, apic_pm_state.apic_ldr);
+       apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
+       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_P4THERMAL
+       if (maxlvt >= 5)
+               apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
+#endif
+       if (maxlvt >= 4)
+               apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
+       apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
+       apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
+       apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
+       apic_write(APIC_ESR, 0);
+       apic_read(APIC_ESR);
+       apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
+       apic_write(APIC_ESR, 0);
+       apic_read(APIC_ESR);
+       local_irq_restore(flags);
        return 0;
 }
-early_param("lapic", parse_lapic);
 
-static int __init parse_nolapic(char *arg)
+/*
+ * 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 = {
+       set_kset_name("lapic"),
+       .resume         = lapic_resume,
+       .suspend        = lapic_suspend,
+};
+
+static struct sys_device device_lapic = {
+       .id     = 0,
+       .cls    = &lapic_sysclass,
+};
+
+static void __devinit apic_pm_activate(void)
 {
-       lapic_disable();
-       return 0;
+       apic_pm_state.active = 1;
 }
-early_param("nolapic", parse_nolapic);
 
+static int __init init_lapic_sysfs(void)
+{
+       int error;
+
+       if (!cpu_has_apic)
+               return 0;
+       /* XXX: remove suspend/resume procs if !apic_pm_state.active? */
+
+       error = sysdev_class_register(&lapic_sysclass);
+       if (!error)
+               error = sysdev_register(&device_lapic);
+       return error;
+}
+device_initcall(init_lapic_sysfs);
+
+#else  /* CONFIG_PM */
+
+static void apic_pm_activate(void) { }
+
+#endif /* CONFIG_PM */
index c76be11..f003a4c 100644 (file)
@@ -1588,7 +1588,7 @@ void /*__init*/ print_local_APIC(void * dummy)
        v = apic_read(APIC_LVR);
        printk(KERN_INFO "... APIC VERSION: %08x\n", v);
        ver = GET_APIC_VERSION(v);
-       maxlvt = get_maxlvt();
+       maxlvt = lapic_get_maxlvt();
 
        v = apic_read(APIC_TASKPRI);
        printk(KERN_DEBUG "... APIC TASKPRI: %08x (%02x)\n", v, v & APIC_TPRI_MASK);
index 5785d84..0f2ca59 100644 (file)
@@ -10,7 +10,6 @@
  * io_apic.c.)
  */
 
-#include <asm/uaccess.h>
 #include <linux/module.h>
 #include <linux/seq_file.h>
 #include <linux/interrupt.h>
 
 #include <asm/idle.h>
 
+#include <asm/apic.h>
+#include <asm/uaccess.h>
+
 DEFINE_PER_CPU(irq_cpustat_t, irq_stat) ____cacheline_internodealigned_in_smp;
 EXPORT_PER_CPU_SYMBOL(irq_stat);
 
-#ifndef CONFIG_X86_LOCAL_APIC
 /*
  * 'what should we do if we get a hw irq event on an illegal vector'.
  * each architecture has to answer this themselves.
  */
 void ack_bad_irq(unsigned int irq)
 {
-       printk("unexpected IRQ trap at vector %02x\n", irq);
-}
+       printk(KERN_ERR "unexpected IRQ trap at vector %02x\n", irq);
+
+#ifdef CONFIG_X86_LOCAL_APIC
+       /*
+        * Currently unexpected vectors happen only on SMP and APIC.
+        * We _must_ ack these because every local APIC has only N
+        * irq slots per priority level, and a 'hanging, unacked' IRQ
+        * holds up an irq slot - in excessive cases (when multiple
+        * unexpected vectors occur) that might lock up the APIC
+        * completely.
+        * But only ack when the APIC is enabled -AK
+        */
+       if (cpu_has_apic)
+               ack_APIC_irq();
 #endif
+}
 
 #ifdef CONFIG_4KSTACKS
 /*
index 6ddffe8..6cdd941 100644 (file)
@@ -600,7 +600,7 @@ wakeup_secondary_cpu(int logical_apicid, unsigned long start_eip)
        /*
         * Due to the Pentium erratum 3AP.
         */
-       maxlvt = get_maxlvt();
+       maxlvt = lapic_get_maxlvt();
        if (maxlvt > 3) {
                apic_read_around(APIC_SPIV);
                apic_write(APIC_ESR, 0);
@@ -697,7 +697,7 @@ wakeup_secondary_cpu(int phys_apicid, unsigned long start_eip)
         */
        Dprintk("#startup loops: %d.\n", num_starts);
 
-       maxlvt = get_maxlvt();
+       maxlvt = lapic_get_maxlvt();
 
        for (j = 1; j <= num_starts; j++) {
                Dprintk("Sending STARTUP #%d.\n",j);
index 3a61206..ccf64fa 100644 (file)
@@ -97,7 +97,7 @@ static inline void ack_APIC_irq(void)
 
 extern void (*wait_timer_tick)(void);
 
-extern int get_maxlvt(void);
+extern int lapic_get_maxlvt(void);
 extern void clear_local_APIC(void);
 extern void connect_bsp_APIC (void);
 extern void disconnect_bsp_APIC (int virt_wire_setup);