Linux-2.6.12-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!
diff --git a/arch/i386/kernel/nmi.c b/arch/i386/kernel/nmi.c
new file mode 100644
index 0000000..f5b0c50
--- /dev/null
+++ b/arch/i386/kernel/nmi.c
@@ -0,0 +1,570 @@
+/*
+ * linux/arch/i386/nmi.c
+ *
+ * NMI watchdog support on APIC systems
+ *
+ * Started by Ingo Molnar <mingo@redhat.com>
+ *
+ * Fixes:
+ * Mikael Pettersson : AMD K7 support for local APIC NMI watchdog.
+ * Mikael Pettersson : Power Management for local APIC NMI watchdog.
+ * Mikael Pettersson : Pentium 4 support for local APIC NMI watchdog.
+ * Pavel Machek and
+ * Mikael Pettersson : PM converted to driver model. Disable/enable API.
+ */
+
+#include <linux/config.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/module.h>
+#include <linux/nmi.h>
+#include <linux/sysdev.h>
+#include <linux/sysctl.h>
+
+#include <asm/smp.h>
+#include <asm/mtrr.h>
+#include <asm/mpspec.h>
+#include <asm/nmi.h>
+
+#include "mach_traps.h"
+
+unsigned int nmi_watchdog = NMI_NONE;
+extern int unknown_nmi_panic;
+static unsigned int nmi_hz = HZ;
+static unsigned int nmi_perfctr_msr; /* the MSR to reset in NMI handler */
+static unsigned int nmi_p4_cccr_val;
+extern void show_registers(struct pt_regs *regs);
+
+/*
+ * lapic_nmi_owner tracks the ownership of the lapic NMI hardware:
+ * - it may be reserved by some other driver, or not
+ * - when not reserved by some other driver, it may be used for
+ * the NMI watchdog, or not
+ *
+ * This is maintained separately from nmi_active because the NMI
+ * watchdog may also be driven from the I/O APIC timer.
+ */
+static DEFINE_SPINLOCK(lapic_nmi_owner_lock);
+static unsigned int lapic_nmi_owner;
+#define LAPIC_NMI_WATCHDOG (1<<0)
+#define LAPIC_NMI_RESERVED (1<<1)
+
+/* nmi_active:
+ * +1: the lapic NMI watchdog is active, but can be disabled
+ * 0: the lapic NMI watchdog has not been set up, and cannot
+ * be enabled
+ * -1: the lapic NMI watchdog is disabled, but can be enabled
+ */
+int nmi_active;
+
+#define K7_EVNTSEL_ENABLE (1 << 22)
+#define K7_EVNTSEL_INT (1 << 20)
+#define K7_EVNTSEL_OS (1 << 17)
+#define K7_EVNTSEL_USR (1 << 16)
+#define K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING 0x76
+#define K7_NMI_EVENT K7_EVENT_CYCLES_PROCESSOR_IS_RUNNING
+
+#define P6_EVNTSEL0_ENABLE (1 << 22)
+#define P6_EVNTSEL_INT (1 << 20)
+#define P6_EVNTSEL_OS (1 << 17)
+#define P6_EVNTSEL_USR (1 << 16)
+#define P6_EVENT_CPU_CLOCKS_NOT_HALTED 0x79
+#define P6_NMI_EVENT P6_EVENT_CPU_CLOCKS_NOT_HALTED
+
+#define MSR_P4_MISC_ENABLE 0x1A0
+#define MSR_P4_MISC_ENABLE_PERF_AVAIL (1<<7)
+#define MSR_P4_MISC_ENABLE_PEBS_UNAVAIL (1<<12)
+#define MSR_P4_PERFCTR0 0x300
+#define MSR_P4_CCCR0 0x360
+#define P4_ESCR_EVENT_SELECT(N) ((N)<<25)
+#define P4_ESCR_OS (1<<3)
+#define P4_ESCR_USR (1<<2)
+#define P4_CCCR_OVF_PMI0 (1<<26)
+#define P4_CCCR_OVF_PMI1 (1<<27)
+#define P4_CCCR_THRESHOLD(N) ((N)<<20)
+#define P4_CCCR_COMPLEMENT (1<<19)
+#define P4_CCCR_COMPARE (1<<18)
+#define P4_CCCR_REQUIRED (3<<16)
+#define P4_CCCR_ESCR_SELECT(N) ((N)<<13)
+#define P4_CCCR_ENABLE (1<<12)
+/* Set up IQ_COUNTER0 to behave like a clock, by having IQ_CCCR0 filter
+ CRU_ESCR0 (with any non-null event selector) through a complemented
+ max threshold. [IA32-Vol3, Section 14.9.9] */
+#define MSR_P4_IQ_COUNTER0 0x30C
+#define P4_NMI_CRU_ESCR0 (P4_ESCR_EVENT_SELECT(0x3F)|P4_ESCR_OS|P4_ESCR_USR)
+#define P4_NMI_IQ_CCCR0 \
+ (P4_CCCR_OVF_PMI0|P4_CCCR_THRESHOLD(15)|P4_CCCR_COMPLEMENT| \
+ P4_CCCR_COMPARE|P4_CCCR_REQUIRED|P4_CCCR_ESCR_SELECT(4)|P4_CCCR_ENABLE)
+
+int __init check_nmi_watchdog (void)
+{
+ unsigned int prev_nmi_count[NR_CPUS];
+ int cpu;
+
+ printk(KERN_INFO "testing NMI watchdog ... ");
+
+ for (cpu = 0; cpu < NR_CPUS; cpu++)
+ prev_nmi_count[cpu] = per_cpu(irq_stat, cpu).__nmi_count;
+ local_irq_enable();
+ mdelay((10*1000)/nmi_hz); // wait 10 ticks
+
+ /* FIXME: Only boot CPU is online at this stage. Check CPUs
+ as they come up. */
+ for (cpu = 0; cpu < NR_CPUS; cpu++) {
+#ifdef CONFIG_SMP
+ /* Check cpu_callin_map here because that is set
+ after the timer is started. */
+ if (!cpu_isset(cpu, cpu_callin_map))
+ continue;
+#endif
+ if (nmi_count(cpu) - prev_nmi_count[cpu] <= 5) {
+ printk("CPU#%d: NMI appears to be stuck!\n", cpu);
+ nmi_active = 0;
+ lapic_nmi_owner &= ~LAPIC_NMI_WATCHDOG;
+ return -1;
+ }
+ }
+ printk("OK.\n");
+
+ /* now that we know it works we can reduce NMI frequency to
+ something more reasonable; makes a difference in some configs */
+ if (nmi_watchdog == NMI_LOCAL_APIC)
+ nmi_hz = 1;
+
+ return 0;
+}
+
+static int __init setup_nmi_watchdog(char *str)
+{
+ int nmi;
+
+ get_option(&str, &nmi);
+
+ if (nmi >= NMI_INVALID)
+ return 0;
+ if (nmi == NMI_NONE)
+ nmi_watchdog = nmi;
+ /*
+ * If any other x86 CPU has a local APIC, then
+ * please test the NMI stuff there and send me the
+ * missing bits. Right now Intel P6/P4 and AMD K7 only.
+ */
+ if ((nmi == NMI_LOCAL_APIC) &&
+ (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL) &&
+ (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15))
+ nmi_watchdog = nmi;
+ if ((nmi == NMI_LOCAL_APIC) &&
+ (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) &&
+ (boot_cpu_data.x86 == 6 || boot_cpu_data.x86 == 15))
+ nmi_watchdog = nmi;
+ /*
+ * We can enable the IO-APIC watchdog
+ * unconditionally.
+ */
+ if (nmi == NMI_IO_APIC) {
+ nmi_active = 1;
+ nmi_watchdog = nmi;
+ }
+ return 1;
+}
+
+__setup("nmi_watchdog=", setup_nmi_watchdog);
+
+static void disable_lapic_nmi_watchdog(void)
+{
+ if (nmi_active <= 0)
+ return;
+ switch (boot_cpu_data.x86_vendor) {
+ case X86_VENDOR_AMD:
+ wrmsr(MSR_K7_EVNTSEL0, 0, 0);
+ break;
+ case X86_VENDOR_INTEL:
+ switch (boot_cpu_data.x86) {
+ case 6:
+ if (boot_cpu_data.x86_model > 0xd)
+ break;
+
+ wrmsr(MSR_P6_EVNTSEL0, 0, 0);
+ break;
+ case 15:
+ if (boot_cpu_data.x86_model > 0x3)
+ break;
+
+ wrmsr(MSR_P4_IQ_CCCR0, 0, 0);
+ wrmsr(MSR_P4_CRU_ESCR0, 0, 0);
+ break;
+ }
+ break;
+ }
+ nmi_active = -1;
+ /* tell do_nmi() and others that we're not active any more */
+ nmi_watchdog = 0;
+}
+
+static void enable_lapic_nmi_watchdog(void)
+{
+ if (nmi_active < 0) {
+ nmi_watchdog = NMI_LOCAL_APIC;
+ setup_apic_nmi_watchdog();
+ }
+}
+
+int reserve_lapic_nmi(void)
+{
+ unsigned int old_owner;
+
+ spin_lock(&lapic_nmi_owner_lock);
+ old_owner = lapic_nmi_owner;
+ lapic_nmi_owner |= LAPIC_NMI_RESERVED;
+ spin_unlock(&lapic_nmi_owner_lock);
+ if (old_owner & LAPIC_NMI_RESERVED)
+ return -EBUSY;
+ if (old_owner & LAPIC_NMI_WATCHDOG)
+ disable_lapic_nmi_watchdog();
+ return 0;
+}
+
+void release_lapic_nmi(void)
+{
+ unsigned int new_owner;
+
+ spin_lock(&lapic_nmi_owner_lock);
+ new_owner = lapic_nmi_owner & ~LAPIC_NMI_RESERVED;
+ lapic_nmi_owner = new_owner;
+ spin_unlock(&lapic_nmi_owner_lock);
+ if (new_owner & LAPIC_NMI_WATCHDOG)
+ enable_lapic_nmi_watchdog();
+}
+
+void disable_timer_nmi_watchdog(void)
+{
+ if ((nmi_watchdog != NMI_IO_APIC) || (nmi_active <= 0))
+ return;
+
+ unset_nmi_callback();
+ nmi_active = -1;
+ nmi_watchdog = NMI_NONE;
+}
+
+void enable_timer_nmi_watchdog(void)
+{
+ if (nmi_active < 0) {
+ nmi_watchdog = NMI_IO_APIC;
+ touch_nmi_watchdog();
+ nmi_active = 1;
+ }
+}
+
+#ifdef CONFIG_PM
+
+static int nmi_pm_active; /* nmi_active before suspend */
+
+static int lapic_nmi_suspend(struct sys_device *dev, u32 state)
+{
+ nmi_pm_active = nmi_active;
+ disable_lapic_nmi_watchdog();
+ return 0;
+}
+
+static int lapic_nmi_resume(struct sys_device *dev)
+{
+ if (nmi_pm_active > 0)
+ enable_lapic_nmi_watchdog();
+ return 0;
+}
+
+
+static struct sysdev_class nmi_sysclass = {
+ set_kset_name("lapic_nmi"),
+ .resume = lapic_nmi_resume,
+ .suspend = lapic_nmi_suspend,
+};
+
+static struct sys_device device_lapic_nmi = {
+ .id = 0,
+ .cls = &nmi_sysclass,
+};
+
+static int __init init_lapic_nmi_sysfs(void)
+{
+ int error;
+
+ if (nmi_active == 0 || nmi_watchdog != NMI_LOCAL_APIC)
+ return 0;
+
+ error = sysdev_class_register(&nmi_sysclass);
+ if (!error)
+ error = sysdev_register(&device_lapic_nmi);
+ return error;
+}
+/* must come after the local APIC's device_initcall() */
+late_initcall(init_lapic_nmi_sysfs);
+
+#endif /* CONFIG_PM */
+
+/*
+ * Activate the NMI watchdog via the local APIC.
+ * Original code written by Keith Owens.
+ */
+
+static void clear_msr_range(unsigned int base, unsigned int n)
+{
+ unsigned int i;
+
+ for(i = 0; i < n; ++i)
+ wrmsr(base+i, 0, 0);
+}
+
+static void setup_k7_watchdog(void)
+{
+ unsigned int evntsel;
+
+ nmi_perfctr_msr = MSR_K7_PERFCTR0;
+
+ clear_msr_range(MSR_K7_EVNTSEL0, 4);
+ clear_msr_range(MSR_K7_PERFCTR0, 4);
+
+ evntsel = K7_EVNTSEL_INT
+ | K7_EVNTSEL_OS
+ | K7_EVNTSEL_USR
+ | K7_NMI_EVENT;
+
+ wrmsr(MSR_K7_EVNTSEL0, evntsel, 0);
+ Dprintk("setting K7_PERFCTR0 to %08lx\n", -(cpu_khz/nmi_hz*1000));
+ wrmsr(MSR_K7_PERFCTR0, -(cpu_khz/nmi_hz*1000), -1);
+ apic_write(APIC_LVTPC, APIC_DM_NMI);
+ evntsel |= K7_EVNTSEL_ENABLE;
+ wrmsr(MSR_K7_EVNTSEL0, evntsel, 0);
+}
+
+static void setup_p6_watchdog(void)
+{
+ unsigned int evntsel;
+
+ nmi_perfctr_msr = MSR_P6_PERFCTR0;
+
+ clear_msr_range(MSR_P6_EVNTSEL0, 2);
+ clear_msr_range(MSR_P6_PERFCTR0, 2);
+
+ evntsel = P6_EVNTSEL_INT
+ | P6_EVNTSEL_OS
+ | P6_EVNTSEL_USR
+ | P6_NMI_EVENT;
+
+ wrmsr(MSR_P6_EVNTSEL0, evntsel, 0);
+ Dprintk("setting P6_PERFCTR0 to %08lx\n", -(cpu_khz/nmi_hz*1000));
+ wrmsr(MSR_P6_PERFCTR0, -(cpu_khz/nmi_hz*1000), 0);
+ apic_write(APIC_LVTPC, APIC_DM_NMI);
+ evntsel |= P6_EVNTSEL0_ENABLE;
+ wrmsr(MSR_P6_EVNTSEL0, evntsel, 0);
+}
+
+static int setup_p4_watchdog(void)
+{
+ unsigned int misc_enable, dummy;
+
+ rdmsr(MSR_P4_MISC_ENABLE, misc_enable, dummy);
+ if (!(misc_enable & MSR_P4_MISC_ENABLE_PERF_AVAIL))
+ return 0;
+
+ nmi_perfctr_msr = MSR_P4_IQ_COUNTER0;
+ nmi_p4_cccr_val = P4_NMI_IQ_CCCR0;
+#ifdef CONFIG_SMP
+ if (smp_num_siblings == 2)
+ nmi_p4_cccr_val |= P4_CCCR_OVF_PMI1;
+#endif
+
+ if (!(misc_enable & MSR_P4_MISC_ENABLE_PEBS_UNAVAIL))
+ clear_msr_range(0x3F1, 2);
+ /* MSR 0x3F0 seems to have a default value of 0xFC00, but current
+ docs doesn't fully define it, so leave it alone for now. */
+ if (boot_cpu_data.x86_model >= 0x3) {
+ /* MSR_P4_IQ_ESCR0/1 (0x3ba/0x3bb) removed */
+ clear_msr_range(0x3A0, 26);
+ clear_msr_range(0x3BC, 3);
+ } else {
+ clear_msr_range(0x3A0, 31);
+ }
+ clear_msr_range(0x3C0, 6);
+ clear_msr_range(0x3C8, 6);
+ clear_msr_range(0x3E0, 2);
+ clear_msr_range(MSR_P4_CCCR0, 18);
+ clear_msr_range(MSR_P4_PERFCTR0, 18);
+
+ wrmsr(MSR_P4_CRU_ESCR0, P4_NMI_CRU_ESCR0, 0);
+ wrmsr(MSR_P4_IQ_CCCR0, P4_NMI_IQ_CCCR0 & ~P4_CCCR_ENABLE, 0);
+ Dprintk("setting P4_IQ_COUNTER0 to 0x%08lx\n", -(cpu_khz/nmi_hz*1000));
+ wrmsr(MSR_P4_IQ_COUNTER0, -(cpu_khz/nmi_hz*1000), -1);
+ apic_write(APIC_LVTPC, APIC_DM_NMI);
+ wrmsr(MSR_P4_IQ_CCCR0, nmi_p4_cccr_val, 0);
+ return 1;
+}
+
+void setup_apic_nmi_watchdog (void)
+{
+ switch (boot_cpu_data.x86_vendor) {
+ case X86_VENDOR_AMD:
+ if (boot_cpu_data.x86 != 6 && boot_cpu_data.x86 != 15)
+ return;
+ setup_k7_watchdog();
+ break;
+ case X86_VENDOR_INTEL:
+ switch (boot_cpu_data.x86) {
+ case 6:
+ if (boot_cpu_data.x86_model > 0xd)
+ return;
+
+ setup_p6_watchdog();
+ break;
+ case 15:
+ if (boot_cpu_data.x86_model > 0x3)
+ return;
+
+ if (!setup_p4_watchdog())
+ return;
+ break;
+ default:
+ return;
+ }
+ break;
+ default:
+ return;
+ }
+ lapic_nmi_owner = LAPIC_NMI_WATCHDOG;
+ nmi_active = 1;
+}
+
+/*
+ * the best way to detect whether a CPU has a 'hard lockup' problem
+ * is to check it's local APIC timer IRQ counts. If they are not
+ * changing then that CPU has some problem.
+ *
+ * as these watchdog NMI IRQs are generated on every CPU, we only
+ * have to check the current processor.
+ *
+ * since NMIs don't listen to _any_ locks, we have to be extremely
+ * careful not to rely on unsafe variables. The printk might lock
+ * up though, so we have to break up any console locks first ...
+ * [when there will be more tty-related locks, break them up
+ * here too!]
+ */
+
+static unsigned int
+ last_irq_sums [NR_CPUS],
+ alert_counter [NR_CPUS];
+
+void touch_nmi_watchdog (void)
+{
+ int i;
+
+ /*
+ * Just reset the alert counters, (other CPUs might be
+ * spinning on locks we hold):
+ */
+ for (i = 0; i < NR_CPUS; i++)
+ alert_counter[i] = 0;
+}
+
+extern void die_nmi(struct pt_regs *, const char *msg);
+
+void nmi_watchdog_tick (struct pt_regs * regs)
+{
+
+ /*
+ * Since current_thread_info()-> is always on the stack, and we
+ * always switch the stack NMI-atomically, it's safe to use
+ * smp_processor_id().
+ */
+ int sum, cpu = smp_processor_id();
+
+ sum = per_cpu(irq_stat, cpu).apic_timer_irqs;
+
+ if (last_irq_sums[cpu] == sum) {
+ /*
+ * Ayiee, looks like this CPU is stuck ...
+ * wait a few IRQs (5 seconds) before doing the oops ...
+ */
+ alert_counter[cpu]++;
+ if (alert_counter[cpu] == 5*nmi_hz)
+ die_nmi(regs, "NMI Watchdog detected LOCKUP");
+ } else {
+ last_irq_sums[cpu] = sum;
+ alert_counter[cpu] = 0;
+ }
+ if (nmi_perfctr_msr) {
+ if (nmi_perfctr_msr == MSR_P4_IQ_COUNTER0) {
+ /*
+ * P4 quirks:
+ * - An overflown perfctr will assert its interrupt
+ * until the OVF flag in its CCCR is cleared.
+ * - LVTPC is masked on interrupt and must be
+ * unmasked by the LVTPC handler.
+ */
+ wrmsr(MSR_P4_IQ_CCCR0, nmi_p4_cccr_val, 0);
+ apic_write(APIC_LVTPC, APIC_DM_NMI);
+ }
+ else if (nmi_perfctr_msr == MSR_P6_PERFCTR0) {
+ /* Only P6 based Pentium M need to re-unmask
+ * the apic vector but it doesn't hurt
+ * other P6 variant */
+ apic_write(APIC_LVTPC, APIC_DM_NMI);
+ }
+ wrmsr(nmi_perfctr_msr, -(cpu_khz/nmi_hz*1000), -1);
+ }
+}
+
+#ifdef CONFIG_SYSCTL
+
+static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu)
+{
+ unsigned char reason = get_nmi_reason();
+ char buf[64];
+
+ if (!(reason & 0xc0)) {
+ sprintf(buf, "NMI received for unknown reason %02x\n", reason);
+ die_nmi(regs, buf);
+ }
+ return 0;
+}
+
+/*
+ * proc handler for /proc/sys/kernel/unknown_nmi_panic
+ */
+int proc_unknown_nmi_panic(ctl_table *table, int write, struct file *file,
+ void __user *buffer, size_t *length, loff_t *ppos)
+{
+ int old_state;
+
+ old_state = unknown_nmi_panic;
+ proc_dointvec(table, write, file, buffer, length, ppos);
+ if (!!old_state == !!unknown_nmi_panic)
+ return 0;
+
+ if (unknown_nmi_panic) {
+ if (reserve_lapic_nmi() < 0) {
+ unknown_nmi_panic = 0;
+ return -EBUSY;
+ } else {
+ set_nmi_callback(unknown_nmi_panic_callback);
+ }
+ } else {
+ release_lapic_nmi();
+ unset_nmi_callback();
+ }
+ return 0;
+}
+
+#endif
+
+EXPORT_SYMBOL(nmi_active);
+EXPORT_SYMBOL(nmi_watchdog);
+EXPORT_SYMBOL(reserve_lapic_nmi);
+EXPORT_SYMBOL(release_lapic_nmi);
+EXPORT_SYMBOL(disable_timer_nmi_watchdog);
+EXPORT_SYMBOL(enable_timer_nmi_watchdog);