[PATCH] i386: Add SMP support on i386 to reservation framework
authorDon Zickus <dzickus@redhat.com>
Tue, 26 Sep 2006 08:52:26 +0000 (10:52 +0200)
committerAndi Kleen <andi@basil.nowhere.org>
Tue, 26 Sep 2006 08:52:26 +0000 (10:52 +0200)
This patch includes the changes to make the nmi watchdog on i386 SMP aware.
A bunch of code was moved around to make it simpler to read.  In addition,
it is now possible to determine if a particular NMI was the result of the
watchdog or not.  This feature allows the kernel to filter out unknown NMIs
easier.

Signed-off-by: Don Zickus <dzickus@redhat.com>
Signed-off-by: Andi Kleen <ak@suse.de>
arch/i386/kernel/apic.c
arch/i386/kernel/nmi.c
arch/i386/kernel/traps.c
arch/i386/oprofile/nmi_timer_int.c
include/asm-i386/nmi.h

index 8c844d07862f6f9eb9103842f783a0cdf495cda3..1a34fc57800bc4e8751b9bf7948f876e91e28038 100644 (file)
@@ -586,8 +586,7 @@ void __devinit setup_local_APIC(void)
                        printk("No ESR for 82489DX.\n");
        }
 
-       if (nmi_watchdog == NMI_LOCAL_APIC)
-               setup_apic_nmi_watchdog();
+       setup_apic_nmi_watchdog(NULL);
        apic_pm_activate();
 }
 
index 5d58dfeacd5943893d967d652682bf789e3df7ba..d8800434303497b0df822626e4907cae0c52dd1b 100644 (file)
 
 #include <asm/smp.h>
 #include <asm/nmi.h>
+#include <asm/kdebug.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);
-
 /* perfctr_nmi_owner tracks the ownership of the perfctr registers:
  * evtsel_nmi_owner tracks the ownership of the event selection
  * - different performance counters/ event selection may be reserved for
@@ -63,51 +57,31 @@ static unsigned int lapic_nmi_owner;
 #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
+ * >0: 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
+ *  0: the lapic NMI watchdog is disabled, but can be enabled
  */
-int nmi_active;
+atomic_t nmi_active = ATOMIC_INIT(0);          /* oprofile uses this */
 
-#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
+unsigned int nmi_watchdog = NMI_DEFAULT;
+static unsigned int nmi_hz = HZ;
 
-#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
+struct nmi_watchdog_ctlblk {
+       int enabled;
+       u64 check_bit;
+       unsigned int cccr_msr;
+       unsigned int perfctr_msr;  /* the MSR to reset in NMI handler */
+       unsigned int evntsel_msr;  /* the MSR to select the events to handle */
+};
+static DEFINE_PER_CPU(struct nmi_watchdog_ctlblk, nmi_watchdog_ctlblk);
 
-#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)
+/* local prototypes */
+static void stop_apic_nmi_watchdog(void *unused);
+static int unknown_nmi_panic_callback(struct pt_regs *regs, int cpu);
+
+extern void show_registers(struct pt_regs *regs);
+extern int unknown_nmi_panic;
 
 /* converts an msr to an appropriate reservation bit */
 static inline unsigned int nmi_perfctr_msr_to_bit(unsigned int msr)
@@ -208,6 +182,17 @@ void release_evntsel_nmi(unsigned int msr)
        clear_bit(counter, &__get_cpu_var(evntsel_nmi_owner)[0]);
 }
 
+static __cpuinit inline int nmi_known_cpu(void)
+{
+       switch (boot_cpu_data.x86_vendor) {
+       case X86_VENDOR_AMD:
+               return ((boot_cpu_data.x86 == 15) || (boot_cpu_data.x86 == 6));
+       case X86_VENDOR_INTEL:
+               return ((boot_cpu_data.x86 == 15) || (boot_cpu_data.x86 == 6));
+       }
+       return 0;
+}
+
 #ifdef CONFIG_SMP
 /* The performance counters used by NMI_LOCAL_APIC don't trigger when
  * the CPU is idle. To make sure the NMI watchdog really ticks on all
@@ -234,7 +219,10 @@ static int __init check_nmi_watchdog(void)
        unsigned int *prev_nmi_count;
        int cpu;
 
-       if (nmi_watchdog == NMI_NONE)
+       if ((nmi_watchdog == NMI_NONE) || (nmi_watchdog == NMI_DEFAULT))
+               return 0;
+
+       if (!atomic_read(&nmi_active))
                return 0;
 
        prev_nmi_count = kmalloc(NR_CPUS * sizeof(int), GFP_KERNEL);
@@ -258,18 +246,22 @@ static int __init check_nmi_watchdog(void)
                if (!cpu_isset(cpu, cpu_callin_map))
                        continue;
 #endif
+               if (!per_cpu(nmi_watchdog_ctlblk, cpu).enabled)
+                       continue;
                if (nmi_count(cpu) - prev_nmi_count[cpu] <= 5) {
-                       endflag = 1;
                        printk("CPU#%d: NMI appears to be stuck (%d->%d)!\n",
                                cpu,
                                prev_nmi_count[cpu],
                                nmi_count(cpu));
-                       nmi_active = 0;
-                       lapic_nmi_owner &= ~LAPIC_NMI_WATCHDOG;
-                       kfree(prev_nmi_count);
-                       return -1;
+                       per_cpu(nmi_watchdog_ctlblk, cpu).enabled = 0;
+                       atomic_dec(&nmi_active);
                }
        }
+       if (!atomic_read(&nmi_active)) {
+               kfree(prev_nmi_count);
+               atomic_set(&nmi_active, -1);
+               return -1;
+       }
        endflag = 1;
        printk("OK.\n");
 
@@ -290,31 +282,16 @@ static int __init setup_nmi_watchdog(char *str)
 
        get_option(&str, &nmi);
 
-       if (nmi >= NMI_INVALID)
+       if ((nmi >= NMI_INVALID) || (nmi < NMI_NONE))
                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;
-       }
+       if ((nmi == NMI_LOCAL_APIC) && (nmi_known_cpu() == 0))
+               return 0;  /* no lapic support */
+       nmi_watchdog = nmi;
        return 1;
 }
 
@@ -322,41 +299,30 @@ __setup("nmi_watchdog=", setup_nmi_watchdog);
 
 static void disable_lapic_nmi_watchdog(void)
 {
-       if (nmi_active <= 0)
+       BUG_ON(nmi_watchdog != NMI_LOCAL_APIC);
+
+       if (atomic_read(&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 > 0x4)
-                               break;
+       on_each_cpu(stop_apic_nmi_watchdog, NULL, 0, 1);
 
-                       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;
+       BUG_ON(atomic_read(&nmi_active) != 0);
 }
 
 static void enable_lapic_nmi_watchdog(void)
 {
-       if (nmi_active < 0) {
-               nmi_watchdog = NMI_LOCAL_APIC;
-               setup_apic_nmi_watchdog();
-       }
+       BUG_ON(nmi_watchdog != NMI_LOCAL_APIC);
+
+       /* are we already enabled */
+       if (atomic_read(&nmi_active) != 0)
+               return;
+
+       /* are we lapic aware */
+       if (nmi_known_cpu() <= 0)
+               return;
+
+       on_each_cpu(setup_apic_nmi_watchdog, NULL, 0, 1);
+       touch_nmi_watchdog();
 }
 
 int reserve_lapic_nmi(void)
@@ -388,20 +354,25 @@ void release_lapic_nmi(void)
 
 void disable_timer_nmi_watchdog(void)
 {
-       if ((nmi_watchdog != NMI_IO_APIC) || (nmi_active <= 0))
+       BUG_ON(nmi_watchdog != NMI_IO_APIC);
+
+       if (atomic_read(&nmi_active) <= 0)
                return;
 
-       unset_nmi_callback();
-       nmi_active = -1;
-       nmi_watchdog = NMI_NONE;
+       disable_irq(0);
+       on_each_cpu(stop_apic_nmi_watchdog, NULL, 0, 1);
+
+       BUG_ON(atomic_read(&nmi_active) != 0);
 }
 
 void enable_timer_nmi_watchdog(void)
 {
-       if (nmi_active < 0) {
-               nmi_watchdog = NMI_IO_APIC;
+       BUG_ON(nmi_watchdog != NMI_IO_APIC);
+
+       if (atomic_read(&nmi_active) == 0) {
                touch_nmi_watchdog();
-               nmi_active = 1;
+               on_each_cpu(setup_apic_nmi_watchdog, NULL, 0, 1);
+               enable_irq(0);
        }
 }
 
@@ -411,7 +382,7 @@ static int nmi_pm_active; /* nmi_active before suspend */
 
 static int lapic_nmi_suspend(struct sys_device *dev, pm_message_t state)
 {
-       nmi_pm_active = nmi_active;
+       nmi_pm_active = atomic_read(&nmi_active);
        disable_lapic_nmi_watchdog();
        return 0;
 }
@@ -439,7 +410,13 @@ static int __init init_lapic_nmi_sysfs(void)
 {
        int error;
 
-       if (nmi_active == 0 || nmi_watchdog != NMI_LOCAL_APIC)
+       /* should really be a BUG_ON but b/c this is an
+        * init call, it just doesn't work.  -dcz
+        */
+       if (nmi_watchdog != NMI_LOCAL_APIC)
+               return 0;
+
+       if ( atomic_read(&nmi_active) < 0 )
                return 0;
 
        error = sysdev_class_register(&nmi_sysclass);
@@ -457,143 +434,312 @@ late_initcall(init_lapic_nmi_sysfs);
  * Original code written by Keith Owens.
  */
 
-static void write_watchdog_counter(const char *descr)
+static void write_watchdog_counter(unsigned int perfctr_msr, const char *descr)
 {
        u64 count = (u64)cpu_khz * 1000;
 
        do_div(count, nmi_hz);
        if(descr)
                Dprintk("setting %s to -0x%08Lx\n", descr, count);
-       wrmsrl(nmi_perfctr_msr, 0 - count);
+       wrmsrl(perfctr_msr, 0 - count);
 }
 
+/* Note that these events don't tick when the CPU idles. This means
+   the frequency varies with CPU load. */
+
+#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
+
 static int setup_k7_watchdog(void)
 {
+       unsigned int perfctr_msr, evntsel_msr;
        unsigned int evntsel;
+       struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
 
-       nmi_perfctr_msr = MSR_K7_PERFCTR0;
-
-       if (!reserve_perfctr_nmi(nmi_perfctr_msr))
+       perfctr_msr = MSR_K7_PERFCTR0;
+       evntsel_msr = MSR_K7_EVNTSEL0;
+       if (!reserve_perfctr_nmi(perfctr_msr))
                goto fail;
 
-       if (!reserve_evntsel_nmi(MSR_K7_EVNTSEL0))
+       if (!reserve_evntsel_nmi(evntsel_msr))
                goto fail1;
 
-       wrmsrl(MSR_K7_PERFCTR0, 0UL);
+       wrmsrl(perfctr_msr, 0UL);
 
        evntsel = K7_EVNTSEL_INT
                | K7_EVNTSEL_OS
                | K7_EVNTSEL_USR
                | K7_NMI_EVENT;
 
-       wrmsr(MSR_K7_EVNTSEL0, evntsel, 0);
-       write_watchdog_counter("K7_PERFCTR0");
+       /* setup the timer */
+       wrmsr(evntsel_msr, evntsel, 0);
+       write_watchdog_counter(perfctr_msr, "K7_PERFCTR0");
        apic_write(APIC_LVTPC, APIC_DM_NMI);
        evntsel |= K7_EVNTSEL_ENABLE;
-       wrmsr(MSR_K7_EVNTSEL0, evntsel, 0);
+       wrmsr(evntsel_msr, evntsel, 0);
+
+       wd->perfctr_msr = perfctr_msr;
+       wd->evntsel_msr = evntsel_msr;
+       wd->cccr_msr = 0;  //unused
+       wd->check_bit = 1ULL<<63;
        return 1;
 fail1:
-       release_perfctr_nmi(nmi_perfctr_msr);
+       release_perfctr_nmi(perfctr_msr);
 fail:
        return 0;
 }
 
+static void stop_k7_watchdog(void)
+{
+       struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
+
+       wrmsr(wd->evntsel_msr, 0, 0);
+
+       release_evntsel_nmi(wd->evntsel_msr);
+       release_perfctr_nmi(wd->perfctr_msr);
+}
+
+#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
+
 static int setup_p6_watchdog(void)
 {
+       unsigned int perfctr_msr, evntsel_msr;
        unsigned int evntsel;
+       struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
 
-       nmi_perfctr_msr = MSR_P6_PERFCTR0;
-
-       if (!reserve_perfctr_nmi(nmi_perfctr_msr))
+       perfctr_msr = MSR_P6_PERFCTR0;
+       evntsel_msr = MSR_P6_EVNTSEL0;
+       if (!reserve_perfctr_nmi(perfctr_msr))
                goto fail;
 
-       if (!reserve_evntsel_nmi(MSR_P6_EVNTSEL0))
+       if (!reserve_evntsel_nmi(evntsel_msr))
                goto fail1;
 
+       wrmsrl(perfctr_msr, 0UL);
+
        evntsel = P6_EVNTSEL_INT
                | P6_EVNTSEL_OS
                | P6_EVNTSEL_USR
                | P6_NMI_EVENT;
 
-       wrmsr(MSR_P6_EVNTSEL0, evntsel, 0);
-       write_watchdog_counter("P6_PERFCTR0");
+       /* setup the timer */
+       wrmsr(evntsel_msr, evntsel, 0);
+       write_watchdog_counter(perfctr_msr, "P6_PERFCTR0");
        apic_write(APIC_LVTPC, APIC_DM_NMI);
        evntsel |= P6_EVNTSEL0_ENABLE;
-       wrmsr(MSR_P6_EVNTSEL0, evntsel, 0);
+       wrmsr(evntsel_msr, evntsel, 0);
+
+       wd->perfctr_msr = perfctr_msr;
+       wd->evntsel_msr = evntsel_msr;
+       wd->cccr_msr = 0;  //unused
+       wd->check_bit = 1ULL<<39;
        return 1;
 fail1:
-       release_perfctr_nmi(nmi_perfctr_msr);
+       release_perfctr_nmi(perfctr_msr);
 fail:
        return 0;
 }
 
+static void stop_p6_watchdog(void)
+{
+       struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
+
+       wrmsr(wd->evntsel_msr, 0, 0);
+
+       release_evntsel_nmi(wd->evntsel_msr);
+       release_perfctr_nmi(wd->perfctr_msr);
+}
+
+/* Note that these events don't tick when the CPU idles. This means
+   the frequency varies with CPU load. */
+
+#define MSR_P4_MISC_ENABLE_PERF_AVAIL  (1<<7)
+#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)
+#define P4_CCCR_OVF            (1<<31)
+/* 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] */
+
 static int setup_p4_watchdog(void)
 {
+       unsigned int perfctr_msr, evntsel_msr, cccr_msr;
+       unsigned int evntsel, cccr_val;
        unsigned int misc_enable, dummy;
+       unsigned int ht_num;
+       struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
 
-       rdmsr(MSR_P4_MISC_ENABLE, misc_enable, dummy);
+       rdmsr(MSR_IA32_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;
+       /* detect which hyperthread we are on */
+       if (smp_num_siblings == 2) {
+               unsigned int ebx, apicid;
+
+               ebx = cpuid_ebx(1);
+               apicid = (ebx >> 24) & 0xff;
+               ht_num = apicid & 1;
+       } else
 #endif
+               ht_num = 0;
+
+       /* performance counters are shared resources
+        * assign each hyperthread its own set
+        * (re-use the ESCR0 register, seems safe
+        * and keeps the cccr_val the same)
+        */
+       if (!ht_num) {
+               /* logical cpu 0 */
+               perfctr_msr = MSR_P4_IQ_PERFCTR0;
+               evntsel_msr = MSR_P4_CRU_ESCR0;
+               cccr_msr = MSR_P4_IQ_CCCR0;
+               cccr_val = P4_CCCR_OVF_PMI0 | P4_CCCR_ESCR_SELECT(4);
+       } else {
+               /* logical cpu 1 */
+               perfctr_msr = MSR_P4_IQ_PERFCTR1;
+               evntsel_msr = MSR_P4_CRU_ESCR0;
+               cccr_msr = MSR_P4_IQ_CCCR1;
+               cccr_val = P4_CCCR_OVF_PMI1 | P4_CCCR_ESCR_SELECT(4);
+       }
 
-       if (!reserve_perfctr_nmi(nmi_perfctr_msr))
+       if (!reserve_perfctr_nmi(perfctr_msr))
                goto fail;
 
-       if (!reserve_evntsel_nmi(MSR_P4_CRU_ESCR0))
+       if (!reserve_evntsel_nmi(evntsel_msr))
                goto fail1;
 
-       wrmsr(MSR_P4_CRU_ESCR0, P4_NMI_CRU_ESCR0, 0);
-       wrmsr(MSR_P4_IQ_CCCR0, P4_NMI_IQ_CCCR0 & ~P4_CCCR_ENABLE, 0);
-       write_watchdog_counter("P4_IQ_COUNTER0");
+       evntsel = P4_ESCR_EVENT_SELECT(0x3F)
+               | P4_ESCR_OS
+               | P4_ESCR_USR;
+
+       cccr_val |= P4_CCCR_THRESHOLD(15)
+                | P4_CCCR_COMPLEMENT
+                | P4_CCCR_COMPARE
+                | P4_CCCR_REQUIRED;
+
+       wrmsr(evntsel_msr, evntsel, 0);
+       wrmsr(cccr_msr, cccr_val, 0);
+       write_watchdog_counter(perfctr_msr, "P4_IQ_COUNTER0");
        apic_write(APIC_LVTPC, APIC_DM_NMI);
-       wrmsr(MSR_P4_IQ_CCCR0, nmi_p4_cccr_val, 0);
+       cccr_val |= P4_CCCR_ENABLE;
+       wrmsr(cccr_msr, cccr_val, 0);
+       wd->perfctr_msr = perfctr_msr;
+       wd->evntsel_msr = evntsel_msr;
+       wd->cccr_msr = cccr_msr;
+       wd->check_bit = 1ULL<<39;
        return 1;
 fail1:
-       release_perfctr_nmi(nmi_perfctr_msr);
+       release_perfctr_nmi(perfctr_msr);
 fail:
        return 0;
 }
 
-void setup_apic_nmi_watchdog (void)
+static void stop_p4_watchdog(void)
 {
-       switch (boot_cpu_data.x86_vendor) {
-       case X86_VENDOR_AMD:
-               if (boot_cpu_data.x86 != 6 && boot_cpu_data.x86 != 15)
-                       return;
-               if (!setup_k7_watchdog())
-                       return;
-               break;
-       case X86_VENDOR_INTEL:
-               switch (boot_cpu_data.x86) {
-               case 6:
-                       if (boot_cpu_data.x86_model > 0xd)
-                               return;
+       struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
+
+       wrmsr(wd->cccr_msr, 0, 0);
+       wrmsr(wd->evntsel_msr, 0, 0);
 
-                       if(!setup_p6_watchdog())
+       release_evntsel_nmi(wd->evntsel_msr);
+       release_perfctr_nmi(wd->perfctr_msr);
+}
+
+void setup_apic_nmi_watchdog (void *unused)
+{
+       /* only support LOCAL and IO APICs for now */
+       if ((nmi_watchdog != NMI_LOCAL_APIC) &&
+           (nmi_watchdog != NMI_IO_APIC))
+               return;
+
+       if (nmi_watchdog == NMI_LOCAL_APIC) {
+               switch (boot_cpu_data.x86_vendor) {
+               case X86_VENDOR_AMD:
+                       if (boot_cpu_data.x86 != 6 && boot_cpu_data.x86 != 15)
                                return;
-                       break;
-               case 15:
-                       if (boot_cpu_data.x86_model > 0x4)
+                       if (!setup_k7_watchdog())
                                return;
+                       break;
+               case X86_VENDOR_INTEL:
+                       switch (boot_cpu_data.x86) {
+                       case 6:
+                               if (boot_cpu_data.x86_model > 0xd)
+                                       return;
+
+                               if (!setup_p6_watchdog())
+                                       return;
+                               break;
+                       case 15:
+                               if (boot_cpu_data.x86_model > 0x4)
+                                       return;
 
-                       if (!setup_p4_watchdog())
+                               if (!setup_p4_watchdog())
+                                       return;
+                               break;
+                       default:
                                return;
+                       }
+                       break;
+               default:
+                       return;
+               }
+       }
+       __get_cpu_var(nmi_watchdog_ctlblk.enabled) = 1;
+       atomic_inc(&nmi_active);
+}
+
+static void stop_apic_nmi_watchdog(void *unused)
+{
+       /* only support LOCAL and IO APICs for now */
+       if ((nmi_watchdog != NMI_LOCAL_APIC) &&
+           (nmi_watchdog != NMI_IO_APIC))
+               return;
+
+       if (nmi_watchdog == NMI_LOCAL_APIC) {
+               switch (boot_cpu_data.x86_vendor) {
+               case X86_VENDOR_AMD:
+                       stop_k7_watchdog();
+                       break;
+               case X86_VENDOR_INTEL:
+                       switch (boot_cpu_data.x86) {
+                       case 6:
+                               if (boot_cpu_data.x86_model > 0xd)
+                                       break;
+                               stop_p6_watchdog();
+                               break;
+                       case 15:
+                               if (boot_cpu_data.x86_model > 0x4)
+                                       break;
+                               stop_p4_watchdog();
+                               break;
+                       }
                        break;
                default:
                        return;
                }
-               break;
-       default:
-               return;
        }
-       lapic_nmi_owner = LAPIC_NMI_WATCHDOG;
-       nmi_active = 1;
+       __get_cpu_var(nmi_watchdog_ctlblk.enabled) = 0;
+       atomic_dec(&nmi_active);
 }
 
 /*
@@ -635,7 +781,7 @@ EXPORT_SYMBOL(touch_nmi_watchdog);
 
 extern void die_nmi(struct pt_regs *, const char *msg);
 
-void nmi_watchdog_tick (struct pt_regs * regs)
+void nmi_watchdog_tick (struct pt_regs * regs, unsigned reason)
 {
 
        /*
@@ -644,11 +790,21 @@ void nmi_watchdog_tick (struct pt_regs * regs)
         * smp_processor_id().
         */
        unsigned int sum;
+       int touched = 0;
        int cpu = smp_processor_id();
+       struct nmi_watchdog_ctlblk *wd = &__get_cpu_var(nmi_watchdog_ctlblk);
+       u64 dummy;
+
+       /* check for other users first */
+       if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT)
+                       == NOTIFY_STOP) {
+               touched = 1;
+       }
 
        sum = per_cpu(irq_stat, cpu).apic_timer_irqs;
 
-       if (last_irq_sums[cpu] == sum) {
+       /* if the apic timer isn't firing, this cpu isn't doing much */
+       if (!touched && last_irq_sums[cpu] == sum) {
                /*
                 * Ayiee, looks like this CPU is stuck ...
                 * wait a few IRQs (5 seconds) before doing the oops ...
@@ -663,26 +819,41 @@ void nmi_watchdog_tick (struct pt_regs * regs)
                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);
+       /* see if the nmi watchdog went off */
+       if (wd->enabled) {
+               if (nmi_watchdog == NMI_LOCAL_APIC) {
+                       rdmsrl(wd->perfctr_msr, dummy);
+                       if (dummy & wd->check_bit){
+                               /* this wasn't a watchdog timer interrupt */
+                               goto done;
+                       }
+
+                       /* only Intel P4 uses the cccr msr */
+                       if (wd->cccr_msr != 0) {
+                               /*
+                                * 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.
+                                */
+                               rdmsrl(wd->cccr_msr, dummy);
+                               dummy &= ~P4_CCCR_OVF;
+                               wrmsrl(wd->cccr_msr, dummy);
+                               apic_write(APIC_LVTPC, APIC_DM_NMI);
+                       }
+                       else if (wd->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);
+                       }
+                       /* start the cycle over again */
+                       write_watchdog_counter(wd->perfctr_msr, NULL);
                }
-               write_watchdog_counter(NULL);
        }
+done:
+       return;
 }
 
 #ifdef CONFIG_SYSCTL
index 7e9edafffd8ad8cbac338870357f2a3b2478238b..3a07b2677e2ae0d4a7ea8f1fd1546b3710aa1167 100644 (file)
@@ -724,7 +724,7 @@ static void default_do_nmi(struct pt_regs * regs)
                 * so it must be the NMI watchdog.
                 */
                if (nmi_watchdog) {
-                       nmi_watchdog_tick(regs);
+                       nmi_watchdog_tick(regs, reason);
                        return;
                }
 #endif
index 930a1127bb309e0ff9030384f452e1641d59ea96..a33a73bb502d2f40b153dbe9bbeb00f6f29b5414 100644 (file)
@@ -42,9 +42,7 @@ static void timer_stop(void)
 
 int __init op_nmi_timer_init(struct oprofile_operations * ops)
 {
-       extern int nmi_active;
-
-       if (nmi_active <= 0)
+       if (atomic_read(&nmi_active) <= 0)
                return -ENODEV;
 
        ops->start = timer_start;
index 27fc9e6f630e7f38b910a94b934d2d436bde57a8..4cda6801ecb87c74ba6f6dec138a548143c8449f 100644 (file)
@@ -32,13 +32,14 @@ extern void release_perfctr_nmi(unsigned int);
 extern int reserve_evntsel_nmi(unsigned int);
 extern void release_evntsel_nmi(unsigned int);
 
-extern void setup_apic_nmi_watchdog (void);
+extern void setup_apic_nmi_watchdog (void *);
 extern int reserve_lapic_nmi(void);
 extern void release_lapic_nmi(void);
 extern void disable_timer_nmi_watchdog(void);
 extern void enable_timer_nmi_watchdog(void);
-extern void nmi_watchdog_tick (struct pt_regs * regs);
+extern void nmi_watchdog_tick (struct pt_regs * regs, unsigned reason);
 
+extern atomic_t nmi_active;
 extern unsigned int nmi_watchdog;
 #define NMI_DEFAULT     -1
 #define NMI_NONE       0