lkml.org 
[lkml]   [2001]   [Feb]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH] 2.4.1-ac1 UP-APIC/NMI watchdog fixes
This patch (against 2.4.1-ac1) contains the following fixes:
* UP-APIC linkage fix: nr_ioapics must be moved from io_apic.c to
mpparse.c to permit linking the kernel in pure UP-APIC configs.
* NMI watchdog cleanups: mark setup_apic_nmi_watchdog() as __init,
fix the K7 init code to not leave any perfctr MSR uninitialised,
avoid having to check CPU type in NMI handler.
(Yes, the merged wrmsr(,,-1) is safe for P6.)

Alan, please include this in -ac2.

/Mikael

--- linux-2.4.1-ac1/arch/i386/kernel/io_apic.c.~1~ Thu Feb 1 15:33:35 2001
+++ linux-2.4.1-ac1/arch/i386/kernel/io_apic.c Thu Feb 1 16:16:11 2001
@@ -38,7 +38,6 @@
/*
* # of IRQ routing registers
*/
-int nr_ioapics;
int nr_ioapic_registers[MAX_IO_APICS];

#if CONFIG_SMP
--- linux-2.4.1-ac1/arch/i386/kernel/mpparse.c.~1~ Thu Feb 1 15:33:35 2001
+++ linux-2.4.1-ac1/arch/i386/kernel/mpparse.c Thu Feb 1 16:15:41 2001
@@ -48,6 +48,8 @@
/* MP IRQ source entries */
int mp_irq_entries;

+int nr_ioapics;
+
int pic_mode;
unsigned long mp_lapic_addr;

--- linux-2.4.1-ac1/arch/i386/kernel/nmi.c.~1~ Thu Feb 1 15:33:35 2001
+++ linux-2.4.1-ac1/arch/i386/kernel/nmi.c Thu Feb 1 18:07:34 2001
@@ -82,25 +82,35 @@
/*
* Activate the NMI watchdog via the local APIC.
* Original code written by Keith Owens.
+ * AMD K7 code by Mikael Pettersson.
*/

+static unsigned int nmi_perfctr_msr; /* the MSR to reset in NMI handler */
#define MSR_K7_EVNTSEL0 0xC0010000
#define MSR_K7_PERFCTR0 0xC0010004
+/* Event 0x76 isn't listed in recent revisions of AMD #22007, and it
+ slows down (but doesn't halt) when the CPU is idle. Unfortunately
+ the K7 doesn't appear to have any other clock-like perfctr event. */
+#define K7_NMI_EVENT 0x76 /* CYCLES_PROCESSOR_IS_RUNNING */
+#define K7_NMI_EVNTSEL ((1<<20)|(3<<16)|K7_NMI_EVENT) /* INT,OS,USR,<event> */

-void setup_apic_nmi_watchdog (void)
+void __init setup_apic_nmi_watchdog (void)
{
int value;

if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD &&
boot_cpu_data.x86 == 6) {
- unsigned evntsel = (1<<20)|(3<<16); /* INT, OS, USR */
-#if 1 /* listed in old docs */
- evntsel |= 0x76; /* CYCLES_PROCESSOR_IS_RUNNING */
-#else /* try this if the above doesn't work */
- evntsel |= 0xC0; /* RETIRED_INSTRUCTIONS */
-#endif
- wrmsr(MSR_K7_EVNTSEL0, 0, 0);
- wrmsr(MSR_K7_PERFCTR0, 0, 0);
+ unsigned i;
+ unsigned evntsel;
+
+ nmi_perfctr_msr = MSR_K7_PERFCTR0;
+
+ for(i = 0; i < 4; ++i) {
+ wrmsr(MSR_K7_EVNTSEL0+i, 0, 0);
+ wrmsr(MSR_K7_PERFCTR0+i, 0, 0);
+ }
+
+ evntsel = K7_NMI_EVNTSEL;
wrmsr(MSR_K7_EVNTSEL0, evntsel, 0);
printk("setting K7_PERFCTR0 to %08lx\n", -(cpu_khz/HZ*1000));
wrmsr(MSR_K7_PERFCTR0, -(cpu_khz/HZ*1000), -1);
@@ -112,6 +122,8 @@
return;
}

+ nmi_perfctr_msr = MSR_IA32_PERFCTR1;
+
/* clear performance counters 0, 1 */

wrmsr(MSR_IA32_EVNTSEL0, 0, 0);
@@ -190,14 +202,6 @@
last_irq_sums[cpu] = sum;
alert_counter[cpu] = 0;
}
- if (cpu_has_apic && (nmi_watchdog == NMI_LOCAL_APIC)) {
- /* XXX: nmi_watchdog should carry this info */
- unsigned msr;
- if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) {
- wrmsr(MSR_K7_PERFCTR0, -(cpu_khz/HZ*1000), -1);
- } else {
- wrmsr(MSR_IA32_PERFCTR1, -(cpu_khz/HZ*1000), 0);
- }
- }
+ if (cpu_has_apic && (nmi_watchdog == NMI_LOCAL_APIC))
+ wrmsr(nmi_perfctr_msr, -(cpu_khz/HZ*1000), -1);
}
-
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2005-03-22 13:27    [W:0.049 / U:10.412 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site