diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/apic.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/i386/kernel/apic.c')
-rw-r--r-- | arch/i386/kernel/apic.c | 1278 |
1 files changed, 1278 insertions, 0 deletions
diff --git a/arch/i386/kernel/apic.c b/arch/i386/kernel/apic.c new file mode 100644 index 00000000000..35c1751ea0b --- /dev/null +++ b/arch/i386/kernel/apic.c @@ -0,0 +1,1278 @@ +/* + * 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; +} |