[Xenomai-core] [PATCH 1/3] Update NMI watchdog for latest Intel CPUs
Add performance-counter NMI watchdog support for recent Intel CPUs. This
should also fix potential overrun (corner) cases for P6-type CPUs as the
current code incorrectly assumes that more than 31 bits are available
as watchdog delay counter.
Refactor some dispatching paths at this chance.
Signed-off-by: Jan Kiszka jan.kis...@web.de
---
include/asm-x86/bits/timer.h |2 +-
ksrc/arch/x86/nmi_32.c | 128 ++
2 files changed, 81 insertions(+), 49 deletions(-)
diff --git a/include/asm-x86/bits/timer.h b/include/asm-x86/bits/timer.h
index b742763..d957c54 100644
--- a/include/asm-x86/bits/timer.h
+++ b/include/asm-x86/bits/timer.h
@@ -37,7 +37,7 @@ static inline void xnarch_program_timer_shot(unsigned long
delay)
#ifdef CONFIG_XENO_HW_NMI_DEBUG_LATENCY
{
extern unsigned long rthal_maxlat_tsc;
- if (delay = (ULONG_MAX - rthal_maxlat_tsc))
+ if (delay = (LONG_MAX - rthal_maxlat_tsc))
rthal_nmi_arm(delay + rthal_maxlat_tsc);
}
#endif /* CONFIG_XENO_HW_NMI_DEBUG_LATENCY */
diff --git a/ksrc/arch/x86/nmi_32.c b/ksrc/arch/x86/nmi_32.c
index f3b3290..78ba905 100644
--- a/ksrc/arch/x86/nmi_32.c
+++ b/ksrc/arch/x86/nmi_32.c
@@ -29,11 +29,19 @@
#include linux/version.h
#include linux/nmi.h
#if LINUX_VERSION_CODE = KERNEL_VERSION(2,6,0)
+#if LINUX_VERSION_CODE = KERNEL_VERSION(2,6,19)
+#include asm/intel_arch_perfmon.h
+#endif /* Linux 2.6.19 */
#include asm/nmi.h
#endif /* Linux 2.6 */
#include asm/msr.h
#include asm/xenomai/hal.h
+#define NMI_WD_ARMED 0x0001
+#define NMI_WD_31BITS 0x1000
+#define NMI_WD_P4 0x2000
+#define NMI_WD_P6_OR_LATER 0x4000
+
#define P4_ESCR_EVENT_SELECT(N) ((N)25)
#define P4_ESCR_OS (13)
#define P4_ESCR_USR (12)
@@ -57,7 +65,7 @@
typedef union {
struct {
/* Xenomai watchdog data. */
- unsigned armed;
+ unsigned int flags;
unsigned long perfctr_msr;
unsigned long long next_linux_check;
unsigned int p4_cccr_val;
@@ -69,11 +77,11 @@ typedef union {
} rthal_nmi_wd_t cacheline_aligned;
static rthal_nmi_wd_t rthal_nmi_wds[NR_CPUS];
-static unsigned long rthal_nmi_perfctr_msr;
-static unsigned int rthal_nmi_p4_cccr_val;
static void (*rthal_nmi_emergency) (struct pt_regs *);
#if LINUX_VERSION_CODE KERNEL_VERSION(2,6,19)
+#define MSR_ARCH_PERFMON_PERFCTR0 0xc1
+#define MSR_ARCH_PERFMON_PERFCTR1 0xc2
static void (*rthal_linux_nmi_tick) (struct pt_regs *);
#if LINUX_VERSION_CODE KERNEL_VERSION(2,6,0)
@@ -96,23 +104,6 @@ static int (*rthal_linux_nmi_tick) (struct pt_regs *,
unsigned);
#define rthal_nmi_active atomic_read(nmi_active)
#endif /* Linux = 2.6.19 */
-static void rthal_touch_nmi_watchdog(void)
-{
- unsigned long long next_linux_check;
- int i;
-
- next_linux_check = rthal_rdtsc() + RTHAL_CPU_FREQ;
-
- for (i = 0; i NR_CPUS; i++) {
- rthal_nmi_wd_t *wd = rthal_nmi_wds[i];
-
- wd-perfctr_msr = rthal_nmi_perfctr_msr;
- wd-p4_cccr_val = rthal_nmi_p4_cccr_val;
- wd-armed = 0;
- wd-next_linux_check = next_linux_check;
- }
-}
-
#if LINUX_VERSION_CODE KERNEL_VERSION(2,6,19)
#define CALL_LINUX_NMI rthal_linux_nmi_tick(regs)
#define NMI_RETURN return
@@ -127,7 +118,7 @@ static int rthal_nmi_watchdog_tick(struct pt_regs *regs,
unsigned reason)
rthal_nmi_wd_t *wd = rthal_nmi_wds[cpu];
unsigned long long now;
- if (wd-armed) {
+ if (wd-flags NMI_WD_ARMED) {
if (rthal_rdtsc() - wd-tick_date rthal_maxlat_tsc) {
++wd-early_shots;
wd-next_linux_check = wd-tick_date + rthal_maxlat_tsc;
@@ -148,7 +139,7 @@ static int rthal_nmi_watchdog_tick(struct pt_regs *regs,
unsigned reason)
} while ((long long)(now - wd-next_linux_check) = 0);
}
- if (wd-perfctr_msr == MSR_P4_IQ_COUNTER0) {
+ if (wd-flags NMI_WD_P4) {
/*
* P4 quirks:
* - An overflown perfctr will assert its interrupt
@@ -158,14 +149,19 @@ static int rthal_nmi_watchdog_tick(struct pt_regs *regs,
unsigned reason)
*/
wrmsr(MSR_P4_IQ_CCCR0, wd-p4_cccr_val, 0);
apic_write(APIC_LVTPC, APIC_DM_NMI);
- } else if (rthal_nmi_perfctr_msr == MSR_P6_PERFCTR0) {
- /* Only P6 based Pentium M need to re-unmask
+ } else if (wd-flags NMI_WD_P6_OR_LATER) {
+ /* P6 based Pentium M need to re-unmask
* the apic vector but it doesn't hurt
-* other P6 variant */
+* other P6 variant.
+* ArchPerfom/Core Duo also needs this */
apic_write(APIC_LVTPC, APIC_DM_NMI);
[Xenomai-core] [PATCH 1/3] Update NMI watchdog for latest Intel CPUs
Add performance-counter NMI watchdog support for recent Intel CPUs. This
should also fix potential overrun (corner) cases for P6-type CPUs as the
current code incorrectly assumes that more than 31 bits are available
as watchdog delay counter.
Refactor some dispatching paths at this chance.
Signed-off-by: Jan Kiszka [EMAIL PROTECTED]
---
include/asm-x86/bits/timer.h |2
ksrc/arch/x86/nmi_32.c | 128 ++-
2 files changed, 81 insertions(+), 49 deletions(-)
Index: b/include/asm-x86/bits/timer.h
===
--- a/include/asm-x86/bits/timer.h
+++ b/include/asm-x86/bits/timer.h
@@ -37,7 +37,7 @@ static inline void xnarch_program_timer_
#ifdef CONFIG_XENO_HW_NMI_DEBUG_LATENCY
{
extern unsigned long rthal_maxlat_tsc;
- if (delay = (ULONG_MAX - rthal_maxlat_tsc))
+ if (delay = (LONG_MAX - rthal_maxlat_tsc))
rthal_nmi_arm(delay + rthal_maxlat_tsc);
}
#endif /* CONFIG_XENO_HW_NMI_DEBUG_LATENCY */
Index: b/ksrc/arch/x86/nmi_32.c
===
--- a/ksrc/arch/x86/nmi_32.c
+++ b/ksrc/arch/x86/nmi_32.c
@@ -29,11 +29,19 @@
#include linux/version.h
#include linux/nmi.h
#if LINUX_VERSION_CODE = KERNEL_VERSION(2,6,0)
+#if LINUX_VERSION_CODE = KERNEL_VERSION(2,6,19)
+#include asm/intel_arch_perfmon.h
+#endif /* Linux 2.6.19 */
#include asm/nmi.h
#endif /* Linux 2.6 */
#include asm/msr.h
#include asm/xenomai/hal.h
+#define NMI_WD_ARMED 0x0001
+#define NMI_WD_31BITS 0x1000
+#define NMI_WD_P4 0x2000
+#define NMI_WD_P6_OR_LATER 0x4000
+
#define P4_ESCR_EVENT_SELECT(N) ((N)25)
#define P4_ESCR_OS (13)
#define P4_ESCR_USR (12)
@@ -57,7 +65,7 @@
typedef union {
struct {
/* Xenomai watchdog data. */
- unsigned armed;
+ unsigned int flags;
unsigned long perfctr_msr;
unsigned long long next_linux_check;
unsigned int p4_cccr_val;
@@ -69,11 +77,11 @@ typedef union {
} rthal_nmi_wd_t cacheline_aligned;
static rthal_nmi_wd_t rthal_nmi_wds[NR_CPUS];
-static unsigned long rthal_nmi_perfctr_msr;
-static unsigned int rthal_nmi_p4_cccr_val;
static void (*rthal_nmi_emergency) (struct pt_regs *);
#if LINUX_VERSION_CODE KERNEL_VERSION(2,6,19)
+#define MSR_ARCH_PERFMON_PERFCTR0 0xc1
+#define MSR_ARCH_PERFMON_PERFCTR1 0xc2
static void (*rthal_linux_nmi_tick) (struct pt_regs *);
#if LINUX_VERSION_CODE KERNEL_VERSION(2,6,0)
@@ -96,23 +104,6 @@ static int (*rthal_linux_nmi_tick) (stru
#define rthal_nmi_active atomic_read(nmi_active)
#endif /* Linux = 2.6.19 */
-static void rthal_touch_nmi_watchdog(void)
-{
- unsigned long long next_linux_check;
- int i;
-
- next_linux_check = rthal_rdtsc() + RTHAL_CPU_FREQ;
-
- for (i = 0; i NR_CPUS; i++) {
- rthal_nmi_wd_t *wd = rthal_nmi_wds[i];
-
- wd-perfctr_msr = rthal_nmi_perfctr_msr;
- wd-p4_cccr_val = rthal_nmi_p4_cccr_val;
- wd-armed = 0;
- wd-next_linux_check = next_linux_check;
- }
-}
-
#if LINUX_VERSION_CODE KERNEL_VERSION(2,6,19)
#define CALL_LINUX_NMI rthal_linux_nmi_tick(regs)
#define NMI_RETURN return
@@ -127,7 +118,7 @@ static int rthal_nmi_watchdog_tick(struc
rthal_nmi_wd_t *wd = rthal_nmi_wds[cpu];
unsigned long long now;
- if (wd-armed) {
+ if (wd-flags NMI_WD_ARMED) {
if (rthal_rdtsc() - wd-tick_date rthal_maxlat_tsc) {
++wd-early_shots;
wd-next_linux_check = wd-tick_date + rthal_maxlat_tsc;
@@ -148,7 +139,7 @@ static int rthal_nmi_watchdog_tick(struc
} while ((long long)(now - wd-next_linux_check) = 0);
}
- if (wd-perfctr_msr == MSR_P4_IQ_COUNTER0) {
+ if (wd-flags NMI_WD_P4) {
/*
* P4 quirks:
* - An overflown perfctr will assert its interrupt
@@ -158,14 +149,19 @@ static int rthal_nmi_watchdog_tick(struc
*/
wrmsr(MSR_P4_IQ_CCCR0, wd-p4_cccr_val, 0);
apic_write(APIC_LVTPC, APIC_DM_NMI);
- } else if (rthal_nmi_perfctr_msr == MSR_P6_PERFCTR0) {
- /* Only P6 based Pentium M need to re-unmask
+ } else if (wd-flags NMI_WD_P6_OR_LATER) {
+ /* P6 based Pentium M need to re-unmask
* the apic vector but it doesn't hurt
-* other P6 variant */
+* other P6 variant.
+* ArchPerfom/Core Duo also needs this */
apic_write(APIC_LVTPC, APIC_DM_NMI);
}
-
- wrmsrl(wd-perfctr_msr, now - wd-next_linux_check);
+
+ if (wd-flags NMI_WD_31BITS)
+
