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-rw-r--r--arch/i386/kernel/apic.c1278
1 files changed, 1278 insertions, 0 deletions
diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c
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+++ b/arch/i386/kernel/apic.c
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+/*
+ * Local APIC handling, local APIC timers
+ *
+ * (c) 1999, 2000 Ingo Molnar <mingo@redhat.com>
+ *
+ * Fixes
+ * Maciej W. Rozycki : Bits for genuine 82489DX APICs;
+ * thanks to Eric Gilmore
+ * and Rolf G. Tews
+ * for testing these extensively.
+ * Maciej W. Rozycki : Various updates and fixes.
+ * Mikael Pettersson : Power Management for UP-APIC.
+ * Pavel Machek and
+ * Mikael Pettersson : PM converted to driver model.
+ */
+
+#include <linux/config.h>
+#include <linux/init.h>
+
+#include <linux/mm.h>
+#include <linux/irq.h>
+#include <linux/delay.h>
+#include <linux/bootmem.h>
+#include <linux/smp_lock.h>
+#include <linux/interrupt.h>
+#include <linux/mc146818rtc.h>
+#include <linux/kernel_stat.h>
+#include <linux/sysdev.h>
+
+#include <asm/atomic.h>
+#include <asm/smp.h>
+#include <asm/mtrr.h>
+#include <asm/mpspec.h>
+#include <asm/desc.h>
+#include <asm/arch_hooks.h>
+#include <asm/hpet.h>
+
+#include <mach_apic.h>
+
+#include "io_ports.h"
+
+/*
+ * Debug level
+ */
+int apic_verbosity;
+
+
+static void apic_pm_activate(void);
+
+/*
+ * '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);
+ /*
+ * 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.
+ */
+ ack_APIC_irq();
+}
+
+void __init apic_intr_init(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
+}
+
+/* Using APIC to generate smp_local_timer_interrupt? */
+int using_apic_timer = 0;
+
+static DEFINE_PER_CPU(int, prof_multiplier) = 1;
+static DEFINE_PER_CPU(int, prof_old_multiplier) = 1;
+static DEFINE_PER_CPU(int, prof_counter) = 1;
+
+static int enabled_via_apicbase;
+
+void enable_NMI_through_LVT0 (void * dummy)
+{
+ unsigned int v, ver;
+
+ ver = apic_read(APIC_LVR);
+ ver = GET_APIC_VERSION(ver);
+ v = APIC_DM_NMI; /* unmask and set to NMI */
+ if (!APIC_INTEGRATED(ver)) /* 82489DX */
+ v |= APIC_LVT_LEVEL_TRIGGER;
+ apic_write_around(APIC_LVT0, v);
+}
+
+int get_physical_broadcast(void)
+{
+ unsigned int lvr, version;
+ lvr = apic_read(APIC_LVR);
+ version = GET_APIC_VERSION(lvr);
+ if (!APIC_INTEGRATED(version) || version >= 0x14)
+ return 0xff;
+ else
+ return 0xf;
+}
+
+int get_maxlvt(void)
+{
+ unsigned int v, ver, maxlvt;
+
+ 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;
+}
+
+void clear_local_APIC(void)
+{
+ int maxlvt;
+ unsigned long v;
+
+ maxlvt = get_maxlvt();
+
+ /*
+ * Masking an LVT entry on a P6 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);
+ }
+
+/* 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);
+
+#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);
+ }
+}
+
+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();
+}
+
+void disconnect_bsp_APIC(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);
+ }
+}
+
+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);
+
+ 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);
+ }
+}
+
+/*
+ * 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 int reg0, reg1;
+
+ /*
+ * 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;
+
+ /*
+ * Check if the version looks reasonably.
+ */
+ reg1 = GET_APIC_VERSION(reg0);
+ if (reg1 == 0x00 || reg1 == 0xff)
+ return 0;
+ reg1 = get_maxlvt();
+ if (reg1 < 0x02 || reg1 == 0xff)
+ 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;
+}
+
+void __init sync_Arb_IDs(void)
+{
+ /* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 */
+ unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
+ if (ver >= 0x14) /* P4 or higher */
+ return;
+ /*
+ * Wait for idle.
+ */
+ 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);
+}
+
+extern void __error_in_apic_c (void);
+
+/*
+ * An initial setup of the virtual wire mode.
+ */
+void __init init_bsp_APIC(void)
+{
+ unsigned long value, ver;
+
+ /*
+ * 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;
+
+ value = apic_read(APIC_LVR);
+ ver = GET_APIC_VERSION(value);
+
+ /*
+ * Do not trust the local APIC being empty at bootup.
+ */
+ clear_local_APIC();
+
+ /*
+ * 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 (!APIC_INTEGRATED(ver)) /* 82489DX */
+ value |= APIC_LVT_LEVEL_TRIGGER;
+ apic_write_around(APIC_LVT1, value);
+}
+
+void __init setup_local_APIC (void)
+{
+ unsigned long oldvalue, value, ver, maxlvt;
+
+ /* 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);
+ }
+
+ value = apic_read(APIC_LVR);
+ ver = GET_APIC_VERSION(value);
+
+ if ((SPURIOUS_APIC_VECTOR & 0x0f) != 0x0f)
+ __error_in_apic_c();
+
+ /*
+ * Double-check whether this APIC is really registered.
+ */
+ if (!apic_id_registered())
+ BUG();
+
+ /*
+ * 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();
+
+ /*
+ * 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);
+
+ /*
+ * 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;
+
+ /*
+ * 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
+ */
+#if 1
+ /* Enable focus processor (bit==0) */
+ value &= ~APIC_SPIV_FOCUS_DISABLED;
+#else
+ /* Disable focus processor (bit==1) */
+ value |= APIC_SPIV_FOCUS_DISABLED;
+#endif
+ /*
+ * 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 (!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);
+
+ value = ERROR_APIC_VECTOR; // enables sending errors
+ 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("Leaving ESR disabled.\n");
+ else
+ printk("No ESR for 82489DX.\n");
+ }
+
+ if (nmi_watchdog == NMI_LOCAL_APIC)
+ setup_apic_nmi_watchdog();
+ apic_pm_activate();
+}
+
+/*
+ * 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.
+ */
+void lapic_shutdown(void)
+{
+ if (!cpu_has_apic || !enabled_via_apicbase)
+ return;
+
+ local_irq_disable();
+ disable_local_APIC();
+ local_irq_enable();
+}
+
+#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, u32 state)
+{
+ unsigned long flags;
+
+ if (!apic_pm_state.active)
+ 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);
+ 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);
+ apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
+
+ local_irq_save(flags);
+ disable_local_APIC();
+ local_irq_restore(flags);
+ return 0;
+}
+
+static int lapic_resume(struct sys_device *dev)
+{
+ unsigned int l, h;
+ unsigned long flags;
+
+ if (!apic_pm_state.active)
+ return 0;
+
+ 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);
+ apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
+ 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;
+}
+
+/*
+ * 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 __init apic_pm_activate(void)
+{
+ apic_pm_state.active = 1;
+}
+
+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 */
+
+/*
+ * Detect and enable local APICs on non-SMP boards.
+ * Original code written by Keir Fraser.
+ */
+
+/*
+ * Knob to control our willingness to enable the local APIC.
+ */
+int enable_local_apic __initdata = 0; /* -1=force-disable, +1=force-enable */
+
+static int __init lapic_disable(char *str)
+{
+ enable_local_apic = -1;
+ clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
+ return 0;
+}
+__setup("nolapic", lapic_disable);
+
+static int __init lapic_enable(char *str)
+{
+ enable_local_apic = 1;
+ return 0;
+}
+__setup("lapic", lapic_enable);
+
+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;
+ else
+ printk(KERN_WARNING "APIC Verbosity level %s not recognised"
+ " use apic=verbose or apic=debug", str);
+
+ return 0;
+}
+
+__setup("apic=", apic_set_verbosity);
+
+static int __init detect_init_APIC (void)
+{
+ u32 h, l, features;
+ extern void get_cpu_vendor(struct cpuinfo_x86*);
+
+ /* Disabled by kernel option? */
+ if (enable_local_apic < 0)
+ return -1;
+
+ /* Workaround for us being called before identify_cpu(). */
+ get_cpu_vendor(&boot_cpu_data);
+
+ 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))
+ break;
+ goto no_apic;
+ case X86_VENDOR_INTEL:
+ if (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15 ||
+ (boot_cpu_data.x86 == 5 && cpu_has_apic))
+ break;
+ goto no_apic;
+ default:
+ goto no_apic;
+ }
+
+ if (!cpu_has_apic) {
+ /*
+ * 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 -- "
+ "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.
+ */
+ rdmsr(MSR_IA32_APICBASE, l, h);
+ if (!(l & MSR_IA32_APICBASE_ENABLE)) {
+ printk("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);
+ enabled_via_apicbase = 1;
+ }
+ }
+ /*
+ * The APIC feature bit should now be enabled
+ * in `cpuid'
+ */
+ features = cpuid_edx(1);
+ if (!(features & (1 << X86_FEATURE_APIC))) {
+ printk("Could not enable APIC!\n");
+ return -1;
+ }
+ set_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
+ mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
+
+ /* 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 __init get_8254_timer_count(void)
+{
+ extern spinlock_t i8253_lock;
+ 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 __init 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) __initdata = 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;
+
+ 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);
+ 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 __init 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 ;)
+ */
+
+ 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;
+}
+
+static unsigned int calibration_result;
+
+void __init setup_boot_APIC_clock(void)
+{
+ apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n");
+ using_apic_timer = 1;
+
+ local_irq_disable();
+
+ calibration_result = calibrate_APIC_clock();
+ /*
+ * Now set up the timer for real.
+ */
+ setup_APIC_timer(calibration_result);
+
+ local_irq_enable();
+}
+
+void __init setup_secondary_APIC_clock(void)
+{
+ setup_APIC_timer(calibration_result);
+}
+
+void __init disable_APIC_timer(void)
+{
+ if (using_apic_timer) {
+ unsigned long v;
+
+ v = apic_read(APIC_LVTT);
+ apic_write_around(APIC_LVTT, v | APIC_LVT_MASKED);
+ }
+}
+
+void enable_APIC_timer(void)
+{
+ if (using_apic_timer) {
+ unsigned long v;
+
+ v = apic_read(APIC_LVTT);
+ apic_write_around(APIC_LVTT, v & ~APIC_LVT_MASKED);
+ }
+}
+
+/*
+ * the frequency of the profiling timer can be changed
+ * by writing a multiplier value into /proc/profile.
+ */
+int setup_profiling_timer(unsigned int multiplier)
+{
+ int i;
+
+ /*
+ * Sanity check. [at least 500 APIC cycles should be
+ * between APIC interrupts as a rule of thumb, to avoid
+ * irqs flooding us]
+ */
+ if ( (!multiplier) || (calibration_result/multiplier < 500))
+ return -EINVAL;
+
+ /*
+ * Set the new multiplier for each CPU. CPUs don't start using the
+ * new values until the next timer interrupt in which they do process
+ * accounting. At that time they also adjust their APIC timers
+ * accordingly.
+ */
+ for (i = 0; i < NR_CPUS; ++i)
+ per_cpu(prof_multiplier, i) = multiplier;
+
+ return 0;
+}
+
+#undef APIC_DIVISOR
+
+/*
+ * 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.
+ */
+
+inline void smp_local_timer_interrupt(struct pt_regs * regs)
+{
+ int cpu = smp_processor_id();
+
+ profile_tick(CPU_PROFILING, regs);
+ if (--per_cpu(prof_counter, cpu) <= 0) {
+ /*
+ * The multiplier may have changed since the last time we got
+ * to this point as a result of the user writing to
+ * /proc/profile. In this case we need to adjust the APIC
+ * timer accordingly.
+ *
+ * Interrupts are already masked off at this point.
+ */
+ per_cpu(prof_counter, cpu) = per_cpu(prof_multiplier, cpu);
+ if (per_cpu(prof_counter, cpu) !=
+ per_cpu(prof_old_multiplier, cpu)) {
+ __setup_APIC_LVTT(
+ calibration_result/
+ per_cpu(prof_counter, cpu));
+ per_cpu(prof_old_multiplier, cpu) =
+ per_cpu(prof_counter, cpu);
+ }
+
+#ifdef CONFIG_SMP
+ update_process_times(user_mode(regs));
+#endif
+ }
+
+ /*
+ * 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.
+ */
+}
+
+/*
+ * 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)
+{
+ 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.
+ */
+ irq_enter();
+ smp_local_timer_interrupt(regs);
+ irq_exit();
+}
+
+/*
+ * This interrupt should _never_ happen with our APIC/SMP architecture
+ */
+fastcall void smp_spurious_interrupt(struct pt_regs *regs)
+{
+ unsigned long v;
+
+ irq_enter();
+ /*
+ * Check if this really is a spurious interrupt and ACK it
+ * if it is a vectored one. Just in case...
+ * Spurious interrupts should not be ACKed.
+ */
+ v = apic_read(APIC_ISR + ((SPURIOUS_APIC_VECTOR & ~0x1f) >> 1));
+ if (v & (1 << (SPURIOUS_APIC_VECTOR & 0x1f)))
+ 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());
+ 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;
+
+ irq_enter();
+ /* First tickle the hardware, only then report what went on. -- REW */
+ v = apic_read(APIC_ESR);
+ apic_write(APIC_ESR, 0);
+ v1 = apic_read(APIC_ESR);
+ ack_APIC_irq();
+ atomic_inc(&irq_err_count);
+
+ /* Here is what the APIC error bits mean:
+ 0: Send CS error
+ 1: Receive CS error
+ 2: Send accept error
+ 3: Receive accept error
+ 4: Reserved
+ 5: Send illegal vector
+ 6: Received illegal vector
+ 7: Illegal register address
+ */
+ printk (KERN_DEBUG "APIC error on CPU%d: %02lx(%02lx)\n",
+ smp_processor_id(), v , v1);
+ irq_exit();
+}
+
+/*
+ * This initializes the IO-APIC and APIC hardware if this is
+ * a UP kernel.
+ */
+int __init APIC_init_uniprocessor (void)
+{
+ if (enable_local_apic < 0)
+ clear_bit(X86_FEATURE_APIC, boot_cpu_data.x86_capability);
+
+ if (!smp_found_config && !cpu_has_apic)
+ return -1;
+
+ /*
+ * 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);
+ return -1;
+ }
+
+ verify_local_APIC();
+
+ connect_bsp_APIC();
+
+ phys_cpu_present_map = physid_mask_of_physid(boot_cpu_physical_apicid);
+
+ setup_local_APIC();
+
+ if (nmi_watchdog == NMI_LOCAL_APIC)
+ check_nmi_watchdog();
+#ifdef CONFIG_X86_IO_APIC
+ if (smp_found_config)
+ if (!skip_ioapic_setup && nr_ioapics)
+ setup_IO_APIC();
+#endif
+ setup_boot_APIC_clock();
+
+ return 0;
+}