[PATCH] lockless MCE i386 port

From: Zwane Mwaikambo
Date: Fri Nov 12 2004 - 11:41:49 EST


Andi fixed the locking issues with respect to printk and MCEs on x86_64,
this is a port of said code with a few small changes due to i386 currently
supporting the extended MCE MSRs on intel processors (also present on
intel x86_64). The addition of hooks allows for the Pentium and P4 MCE
drivers to print additional/extended information. I've also converted the
P4 thermal monitor driver to avoid printing from interrupt context.

Tested on P4 and K7

Signed-off-by: Zwane Mwaikambo <zwane@xxxxxxxxxxx>

arch/i386/kernel/cpu/mcheck/k7.c | 68 ++++++++++-----
arch/i386/kernel/cpu/mcheck/mce.c | 109 ++++++++++++++++++++++++-
arch/i386/kernel/cpu/mcheck/mce.h | 53 ++++++++++++
arch/i386/kernel/cpu/mcheck/p4.c | 165 ++++++++++++++++++++++++++------------
arch/i386/kernel/cpu/mcheck/p5.c | 27 ++++--
arch/i386/kernel/cpu/mcheck/p6.c | 66 +++++++++------
6 files changed, 382 insertions(+), 106 deletions(-)

Index: linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/k7.c
===================================================================
RCS file: /home/cvsroot/linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/k7.c,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 k7.c
--- linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/k7.c 9 Nov 2004 21:54:52 -0000 1.1.1.1
+++ linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/k7.c 12 Nov 2004 04:20:38 -0000
@@ -20,36 +20,54 @@
/* Machine Check Handler For AMD Athlon/Duron */
static asmlinkage void k7_machine_check(struct pt_regs * regs, long error_code)
{
- int recover=1;
- u32 alow, ahigh, high, low;
- u32 mcgstl, mcgsth;
- int i;
-
- rdmsr (MSR_IA32_MCG_STATUS, mcgstl, mcgsth);
- if (mcgstl & (1<<0)) /* Recoverable ? */
+ int i, recover=1;
+ u32 high, low;
+ u64 mcestart;
+ struct mce m, panicm;
+ int panicm_found = 0;
+
+ memset(&m, 0, sizeof(m));
+ m.cpu = smp_processor_id();
+ rdtscll(mcestart);
+ rdmsr (MSR_IA32_MCG_STATUS, m.mcgstl, m.mcgsth);
+ if (m.mcgstl & (1<<0)) /* Recoverable ? */
recover=0;
-
- printk (KERN_EMERG "CPU %d: Machine Check Exception: %08x%08x\n",
- smp_processor_id(), mcgsth, mcgstl);
-
+
for (i=1; i<nr_mce_banks; i++) {
+ m.bank = i;
+ m.tsc = 0;
+ m.stsl = m.stsh = 0;
+ m.addrl = m.addrh = 0;
+ m.miscl = m.misch = 0;
rdmsr (MSR_IA32_MC0_STATUS+i*4,low, high);
if (high&(1<<31)) {
if (high & (1<<29))
recover |= 1;
if (high & (1<<25))
recover |= 2;
- printk (KERN_EMERG "Bank %d: %08x%08x", i, high, low);
+ m.stsl = low;
+ m.stsh = high;
high &= ~(1<<31);
- if (high & (1<<27)) {
- rdmsr (MSR_IA32_MC0_MISC+i*4, alow, ahigh);
- printk ("[%08x%08x]", ahigh, alow);
+ if (high & (1<<27))
+ rdmsr (MSR_IA32_MC0_MISC+i*4, m.miscl, m.misch);
+ if (high & (1<<26))
+ rdmsr (MSR_IA32_MC0_ADDR+i*4, m.addrl, m.addrh);
+
+ /* Error at %eip ? */
+ if (m.mcgstl & (1<<1)) {
+ m.eip = regs->eip;
+ m.cs = regs->xcs;
+ } else {
+ m.eip = 0;
+ m.cs = 0;
}
- if (high & (1<<26)) {
- rdmsr (MSR_IA32_MC0_ADDR+i*4, alow, ahigh);
- printk (" at %08x%08x", ahigh, alow);
+
+ rdtscll(m.tsc);
+ mce_log(&m);
+ if (recover) {
+ panicm = m;
+ panicm_found = 1;
}
- printk ("\n");
/* Clear it */
wrmsr (MSR_IA32_MC0_STATUS+i*4, 0UL, 0UL);
/* Serialize */
@@ -58,13 +76,15 @@ static asmlinkage void k7_machine_check(
}
}

+ if (!panicm_found)
+ panicm = m;
+
if (recover&2)
- panic ("CPU context corrupt");
+ mce_panic("CPU context corrupt", &panicm, mcestart);
if (recover&1)
- panic ("Unable to continue");
- printk (KERN_EMERG "Attempting to continue.\n");
- mcgstl &= ~(1<<2);
- wrmsr (MSR_IA32_MCG_STATUS,mcgstl, mcgsth);
+ mce_panic("Unable to continue", &panicm, mcestart);
+ wrmsr (MSR_IA32_MCG_STATUS, m.mcgstl & ~(1 << 2), m.mcgsth);
+ mce_dump();
}


Index: linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/mce.c
===================================================================
RCS file: /home/cvsroot/linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/mce.c,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 mce.c
--- linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/mce.c 9 Nov 2004 21:54:52 -0000 1.1.1.1
+++ linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/mce.c 12 Nov 2004 15:08:04 -0000
@@ -1,6 +1,7 @@
/*
* mce.c - x86 Machine Check Exception Reporting
* (c) 2002 Alan Cox <alan@xxxxxxxxxx>, Dave Jones <davej@xxxxxxxxxxxxxxxxx>
+ * (c) 2004 Andi Kleen <ak@xxxxxxx>, Zwane Mwaikambo <zwane@xxxxxxxxxxx>
*/

#include <linux/init.h>
@@ -10,6 +11,8 @@
#include <linux/module.h>
#include <linux/smp.h>
#include <linux/thread_info.h>
+#include <linux/rcupdate.h>
+#include <linux/kallsyms.h>

#include <asm/processor.h>
#include <asm/system.h>
@@ -23,7 +26,7 @@ EXPORT_SYMBOL_GPL(nr_mce_banks); /* non-

/* Handle unconfigured int18 (should never happen) */
static asmlinkage void unexpected_machine_check(struct pt_regs * regs, long error_code)
-{
+{
printk(KERN_ERR "CPU#%d: Unexpected int18 (Machine Check).\n", smp_processor_id());
}

@@ -61,6 +64,110 @@ void __init mcheck_init(struct cpuinfo_x
}
}

+/*
+ * Lockless MCE logging infrastructure.
+ * This avoids deadlocks on printk locks without having to break locks. Also
+ * separate MCEs from kernel messages to avoid bogus bug reports.
+ */
+
+struct mce_log mcelog = {
+ MCE_LOG_SIGNATURE,
+ MCE_LOG_LEN,
+};
+
+static void print_mce(struct mce *);
+static void __mce_dump_log(unsigned long data)
+{
+ int i;
+
+ for (i = 0; i < MCE_LOG_LEN; i++) {
+ smp_rmb();
+ if (!mcelog.entry[i].finished)
+ continue;
+ print_mce(&mcelog.entry[i]);
+ }
+}
+
+DECLARE_TASKLET(mce_tasklet, __mce_dump_log, 0);
+
+void mce_log(struct mce *mce)
+{
+ unsigned next, entry;
+ mce->finished = 0;
+ smp_wmb();
+ for (;;) {
+ entry = rcu_dereference(mcelog.next);
+ /* When the buffer fills up discard new entries. Assume
+ that the earlier errors are the more interesting. */
+ if (entry >= MCE_LOG_LEN) {
+ set_bit(MCE_OVERFLOW, &mcelog.flags);
+ return;
+ }
+ /* Old left over entry. Skip. */
+ if (mcelog.entry[entry].finished)
+ continue;
+ smp_rmb();
+ next = entry + 1;
+ if (cmpxchg(&mcelog.next, entry, next) == entry)
+ break;
+ }
+ if (mcelog.ext_entry_len && mce->ext_arg) {
+ char *p = (char *)mcelog.ext_buffer + (entry * mcelog.ext_entry_len);
+ memcpy(p, mce->ext_arg, mcelog.ext_entry_len);
+ mce->ext_arg = p;
+ }
+ memcpy(mcelog.entry + entry, mce, sizeof(struct mce));
+ smp_wmb();
+ mcelog.entry[entry].finished = 1;
+ smp_wmb();
+}
+
+static void print_mce(struct mce *m)
+{
+ printk(KERN_EMERG "CPU %d: Machine Check Exception: %08x%08x\n",
+ m->cpu, m->mcgsth, m->mcgstl);
+
+ printk(KERN_EMERG "Bank %d: %08x%08x", m->bank, m->stsh, m->stsl);
+ if (m->miscl || m->misch)
+ printk("[%08x%08x]", m->misch, m->miscl);
+ if (m->addrl || m->addrh)
+ printk(" at %08x%08x", m->addrl, m->addrh);
+ printk("\n");
+
+ if (m->eip) {
+ printk(KERN_EMERG "EIP %02x:<%08x> ",
+ m->cs, m->eip);
+ if (m->cs == __KERNEL_CS)
+ print_symbol("{%s}", m->eip);
+ printk("\n");
+ }
+
+ if (m->tsc)
+ printk(KERN_EMERG "TSC %016Lx\n", m->tsc);
+ if (m->ext_arg)
+ mcelog.ext_call(m->ext_arg);
+}
+
+void mce_panic(char *msg, struct mce *backup, u64 start)
+{
+ int i;
+
+ oops_in_progress = 1;
+ for (i = 0; i < MCE_LOG_LEN; i++) {
+ if (mcelog.entry[i].tsc < start)
+ continue;
+
+ print_mce(&mcelog.entry[i]);
+ if (backup && mcelog.entry[i].tsc == backup->tsc)
+ backup = NULL;
+ }
+
+ if (backup)
+ print_mce(backup);
+
+ panic(msg);
+}
+
static int __init mcheck_disable(char *str)
{
mce_disabled = 1;
Index: linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/mce.h
===================================================================
RCS file: /home/cvsroot/linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/mce.h,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 mce.h
--- linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/mce.h 9 Nov 2004 21:54:52 -0000 1.1.1.1
+++ linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/mce.h 12 Nov 2004 04:21:34 -0000
@@ -1,5 +1,58 @@
#include <linux/init.h>
+#include <linux/interrupt.h>

+/*
+ * This structure contains all data related to the MCE log.
+ * Also carries a signature to make it easier to find from external debugging tools.
+ * Each entry is only valid when its finished flag is set.
+ */
+
+#define MCE_LOG_LEN 32
+#define MCE_OVERFLOW 0 /* bit 0 in flags means overflow */
+#define MCE_LOG_SIGNATURE "MACHINECHECK"
+#define MCE_GET_RECORD_LEN _IOR('M', 1, int)
+#define MCE_GET_LOG_LEN _IOR('M', 2, int)
+#define MCE_GETCLEAR_FLAGS _IOR('M', 3, int)
+
+struct mce {
+ u64 tsc; /* cpu timestamp counter */
+ u32 stsl;
+ u32 stsh;
+ u32 miscl;
+ u32 misch;
+ u32 addrl;
+ u32 addrh;
+ u32 mcgstl;
+ u32 mcgsth;
+ u32 eip;
+ u8 cs; /* code segment */
+ u8 bank; /* machine check bank */
+ u8 cpu; /* cpu that raised the error */
+ u8 finished; /* entry is valid */
+ void *ext_arg; /* extended feature arg */
+};
+
+struct mce_log {
+ char signature[12]; /* "MACHINECHECK" */
+ unsigned long len; /* = MCE_LOG_LEN */
+ unsigned long next;
+ unsigned long flags;
+ unsigned long pad0;
+ struct mce entry[MCE_LOG_LEN];
+ void *ext_buffer; /* extended feature storage */
+ void (*ext_call)(void *); /* extended feature callback */
+ unsigned long ext_entry_len; /* extended feature argument length */
+};
+
+extern struct tasklet_struct mce_tasklet;
+extern struct mce_log mcelog;
+static void inline mce_dump(void)
+{
+ tasklet_hi_schedule(&mce_tasklet);
+}
+
+void mce_log(struct mce *m);
+void mce_panic(char *msg, struct mce *backup, u64 start);
void amd_mcheck_init(struct cpuinfo_x86 *c);
void intel_p4_mcheck_init(struct cpuinfo_x86 *c);
void intel_p5_mcheck_init(struct cpuinfo_x86 *c);
Index: linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p4.c
===================================================================
RCS file: /home/cvsroot/linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p4.c,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 p4.c
--- linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p4.c 9 Nov 2004 21:54:52 -0000 1.1.1.1
+++ linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p4.c 12 Nov 2004 05:48:00 -0000
@@ -9,6 +9,7 @@
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/smp.h>
+#include <linux/bootmem.h>

#include <asm/processor.h>
#include <asm/system.h>
@@ -32,39 +33,65 @@ struct intel_mce_extended_msrs {
/* u32 *reserved[]; */
};

+static struct intel_mce_extended_msrs mce_ext_buffer[MCE_LOG_LEN];
+
static int mce_num_extended_msrs = 0;


#ifdef CONFIG_X86_MCE_P4THERMAL
static void unexpected_thermal_interrupt(struct pt_regs *regs)
-{
+{
+ ack_APIC_irq();
printk(KERN_ERR "CPU%d: Unexpected LVT TMR interrupt!\n",
smp_processor_id());
add_taint(TAINT_MACHINE_CHECK);
}

/* P4/Xeon Thermal transition interrupt handler */
+static cpumask_t cpu_thermal_status;
+static unsigned long next_thermal_check;
+
+static void intel_thermal_check(unsigned long data)
+{
+ static cpumask_t log;
+ int cpu;
+
+ next_thermal_check = jiffies + HZ*10;
+ for_each_online_cpu(cpu) {
+ if (cpu_isset(cpu, cpu_thermal_status)) {
+ if (cpu_isset(cpu, log))
+ continue;
+
+ printk(KERN_EMERG
+ "CPU%d: Temperature above threshold, cpu clock throttled\n", cpu);
+ cpu_set(cpu, log);
+ } else if (cpu_isset(cpu, log)) {
+ printk(KERN_INFO "CPU%d: Temperature/speed normal\n", cpu);
+ cpu_clear(cpu, log);
+ }
+ }
+}
+
+static DECLARE_TASKLET(thermal_tasklet, intel_thermal_check, 0);
+
static void intel_thermal_interrupt(struct pt_regs *regs)
{
- u32 l, h;
- unsigned int cpu = smp_processor_id();
- static unsigned long next[NR_CPUS];
+ unsigned long l, h;

ack_APIC_irq();

- if (time_after(next[cpu], jiffies))
- return;
-
- next[cpu] = jiffies + HZ*5;
rdmsr(MSR_IA32_THERM_STATUS, l, h);
if (l & 0x1) {
- printk(KERN_EMERG "CPU%d: Temperature above threshold\n", cpu);
- printk(KERN_EMERG "CPU%d: Running in modulated clock mode\n",
- cpu);
+ cpu_set(smp_processor_id(), cpu_thermal_status);
add_taint(TAINT_MACHINE_CHECK);
} else {
- printk(KERN_INFO "CPU%d: Temperature/speed normal\n", cpu);
+ cpu_clear(smp_processor_id(), cpu_thermal_status);
}
+
+ if (time_before(jiffies, next_thermal_check))
+ return;
+
+ tasklet_schedule(&thermal_tasklet);
}

/* Thermal interrupt handler for this CPU setup */
@@ -159,57 +186,83 @@ done:
return mce_num_extended_msrs;
}

+static void intel_print_extended_msr(void *__dbg_msrs)
+{
+ struct intel_mce_extended_msrs *dbg = __dbg_msrs;
+
+ printk(KERN_EMERG "EIP: %08x EFLAGS: %08x\n",
+ dbg->eip, dbg->eflags);
+ printk(KERN_EMERG "EAX: %08x EBX: %08x ECX: %08x EDX: %08x\n",
+ dbg->eax, dbg->ebx, dbg->ecx, dbg->edx);
+ printk (KERN_EMERG "ESI: %08x EDI: %08x EBP: %08x ESP: %08x\n",
+ dbg->esi, dbg->edi, dbg->ebp, dbg->esp);
+}
+
static asmlinkage void intel_machine_check(struct pt_regs * regs, long error_code)
{
- int recover=1;
- u32 alow, ahigh, high, low;
- u32 mcgstl, mcgsth;
- int i;
+ int i, recover = 1;
+ u32 high, low;
+ u64 mcestart;
struct intel_mce_extended_msrs dbg;
+ struct mce m, panicm;
+ int panicm_found = 0;

- rdmsr (MSR_IA32_MCG_STATUS, mcgstl, mcgsth);
- if (mcgstl & (1<<0)) /* Recoverable ? */
- recover=0;
-
- printk (KERN_EMERG "CPU %d: Machine Check Exception: %08x%08x\n",
- smp_processor_id(), mcgsth, mcgstl);
-
- if (intel_get_extended_msrs(&dbg)) {
- printk (KERN_DEBUG "CPU %d: EIP: %08x EFLAGS: %08x\n",
- smp_processor_id(), dbg.eip, dbg.eflags);
- printk (KERN_DEBUG "\teax: %08x ebx: %08x ecx: %08x edx: %08x\n",
- dbg.eax, dbg.ebx, dbg.ecx, dbg.edx);
- printk (KERN_DEBUG "\tesi: %08x edi: %08x ebp: %08x esp: %08x\n",
- dbg.esi, dbg.edi, dbg.ebp, dbg.esp);
- }
+ memset(&m, 0, sizeof(m));
+ m.cpu = smp_processor_id();
+ rdtscll(mcestart);
+ rdmsr(MSR_IA32_MCG_STATUS, m.mcgstl, m.mcgsth);
+ if (m.mcgstl & (1<<0)) /* Recoverable ? */
+ recover = 0;
+
+ if (intel_get_extended_msrs(&dbg))
+ m.ext_arg = &dbg;

for (i=0; i<nr_mce_banks; i++) {
- rdmsr (MSR_IA32_MC0_STATUS+i*4,low, high);
+ m.bank = i;
+ m.tsc = 0;
+ m.stsl = m.stsh = 0;
+ m.addrl = m.addrh = 0;
+ m.miscl = m.misch = 0;
+ rdmsr (MSR_IA32_MC0_STATUS+i*4, low, high);
if (high & (1<<31)) {
if (high & (1<<29))
recover |= 1;
if (high & (1<<25))
recover |= 2;
- printk (KERN_EMERG "Bank %d: %08x%08x", i, high, low);
+ m.stsl = low;
+ m.stsh = high;
high &= ~(1<<31);
- if (high & (1<<27)) {
- rdmsr (MSR_IA32_MC0_MISC+i*4, alow, ahigh);
- printk ("[%08x%08x]", ahigh, alow);
+ if (high & (1<<27))
+ rdmsr (MSR_IA32_MC0_MISC+i*4, m.miscl, m.misch);
+ if (high & (1<<26))
+ rdmsr (MSR_IA32_MC0_ADDR+i*4, m.addrl, m.addrh);
+
+ /* Error at %eip ? */
+ if (m.mcgstl & (1<<1)) {
+ m.eip = regs->eip;
+ m.cs = regs->xcs;
+ } else {
+ m.eip = 0;
+ m.cs = 0;
}
- if (high & (1<<26)) {
- rdmsr (MSR_IA32_MC0_ADDR+i*4, alow, ahigh);
- printk (" at %08x%08x", ahigh, alow);
+
+ rdtscll(m.tsc);
+ mce_log(&m);
+ if (recover) {
+ panicm = m;
+ panicm_found = 1;
}
- printk ("\n");
}
}

+ if (!panicm_found)
+ panicm = m;
+
if (recover & 2)
- panic ("CPU context corrupt");
+ mce_panic("CPU context corrupt", &panicm, mcestart);
if (recover & 1)
- panic ("Unable to continue");
+ mce_panic("Unable to continue", &panicm, mcestart);

- printk(KERN_EMERG "Attempting to continue.\n");
/*
* Do not clear the MSR_IA32_MCi_STATUS if the error is not
* recoverable/continuable.This will allow BIOS to look at the MSRs
@@ -218,7 +271,7 @@ static asmlinkage void intel_machine_che
for (i=0; i<nr_mce_banks; i++) {
u32 msr;
msr = MSR_IA32_MC0_STATUS+i*4;
- rdmsr (msr, low, high);
+ rdmsr(msr, low, high);
if (high&(1<<31)) {
/* Clear it */
wrmsr(msr, 0UL, 0UL);
@@ -227,11 +280,10 @@ static asmlinkage void intel_machine_che
add_taint(TAINT_MACHINE_CHECK);
}
}
- mcgstl &= ~(1<<2);
- wrmsr (MSR_IA32_MCG_STATUS,mcgstl, mcgsth);
+ wrmsr(MSR_IA32_MCG_STATUS, m.mcgstl & ~(1 << 2), m.mcgsth);
+ mce_dump();
}

-
void __init intel_p4_mcheck_init(struct cpuinfo_x86 *c)
{
u32 l, h;
@@ -258,14 +310,25 @@ void __init intel_p4_mcheck_init(struct
/* Check for P4/Xeon extended MCE MSRs */
rdmsr (MSR_IA32_MCG_CAP, l, h);
if (l & (1<<9)) {/* MCG_EXT_P */
+ struct intel_mce_extended_msrs *p;
+
+ if (smp_processor_id() != 0)
+ goto skip;
+
+ p = mce_ext_buffer;
+ memset(p, 0, sizeof(*p) * MCE_LOG_LEN);
+ mcelog.ext_buffer = p;
+ mcelog.ext_call = intel_print_extended_msr;
+ mcelog.ext_entry_len = sizeof(*p);
mce_num_extended_msrs = (l >> 16) & 0xff;
+skip:
printk (KERN_INFO "CPU%d: Intel P4/Xeon Extended MCE MSRs (%d)"
- " available\n",
+ " available\n",
smp_processor_id(), mce_num_extended_msrs);
+ }

#ifdef CONFIG_X86_MCE_P4THERMAL
- /* Check for P4/Xeon Thermal monitor */
- intel_init_thermal(c);
+ /* Check for P4/Xeon Thermal monitor */
+ intel_init_thermal(c);
#endif
- }
}
Index: linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p5.c
===================================================================
RCS file: /home/cvsroot/linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p5.c,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 p5.c
--- linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p5.c 9 Nov 2004 21:54:52 -0000 1.1.1.1
+++ linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p5.c 12 Nov 2004 04:36:16 -0000
@@ -16,23 +16,32 @@

#include "mce.h"

+static void pentium_print_status(void *mc_typel)
+{
+ if ((u32)mc_typel & (1 << 5))
+ printk("Possible thermal failure (CPU on fire?).\n");
+}
+
/* Machine check handler for Pentium class Intel */
static asmlinkage void pentium_machine_check(struct pt_regs * regs, long error_code)
{
- u32 loaddr, hi, lotype;
- rdmsr(MSR_IA32_P5_MC_ADDR, loaddr, hi);
- rdmsr(MSR_IA32_P5_MC_TYPE, lotype, hi);
- printk(KERN_EMERG "CPU#%d: Machine Check Exception: 0x%8X (type 0x%8X).\n", smp_processor_id(), loaddr, lotype);
- if(lotype&(1<<5))
- printk(KERN_EMERG "CPU#%d: Possible thermal failure (CPU on fire ?).\n", smp_processor_id());
+ struct mce m;
+
+ memset(&m, 0, sizeof(m));
+ m.cpu = smp_processor_id();
+ rdmsr(MSR_IA32_P5_MC_ADDR, m.addrl, m.addrh);
+ rdmsr(MSR_IA32_P5_MC_TYPE, m.mcgstl, m.mcgsth);
+ m.ext_arg = (void *)m.mcgstl;
+ mce_log(&m);
add_taint(TAINT_MACHINE_CHECK);
+ mce_dump();
}

/* Set up machine check reporting for processors with Intel style MCE */
void __init intel_p5_mcheck_init(struct cpuinfo_x86 *c)
{
u32 l, h;
-
+
/*Check for MCE support */
if( !cpu_has(c, X86_FEATURE_MCE) )
return;
@@ -40,6 +49,10 @@ void __init intel_p5_mcheck_init(struct
/* Default P5 to off as its often misconnected */
if(mce_disabled != -1)
return;
+
+ mcelog.ext_call = pentium_print_status;
+ mcelog.ext_entry_len = 0;
+
machine_check_vector = pentium_machine_check;
wmb();

Index: linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p6.c
===================================================================
RCS file: /home/cvsroot/linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p6.c,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 p6.c
--- linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p6.c 9 Nov 2004 21:54:52 -0000 1.1.1.1
+++ linux-2.6.10-rc1-mm4/arch/i386/kernel/cpu/mcheck/p6.c 11 Nov 2004 14:42:58 -0000
@@ -19,45 +19,65 @@
/* Machine Check Handler For PII/PIII */
static asmlinkage void intel_machine_check(struct pt_regs * regs, long error_code)
{
- int recover=1;
- u32 alow, ahigh, high, low;
- u32 mcgstl, mcgsth;
- int i;
-
- rdmsr (MSR_IA32_MCG_STATUS, mcgstl, mcgsth);
- if (mcgstl & (1<<0)) /* Recoverable ? */
+ int i, recover=1;
+ u32 high, low;
+ u64 mcestart;
+ struct mce m, panicm;
+ int panicm_found = 0;
+
+ memset(&m, 0, sizeof(m));
+ m.cpu = smp_processor_id();
+ rdtscll(mcestart);
+ rdmsr (MSR_IA32_MCG_STATUS, m.mcgstl, m.mcgsth);
+ if (m.mcgstl & (1<<0)) /* Recoverable ? */
recover=0;

- printk (KERN_EMERG "CPU %d: Machine Check Exception: %08x%08x\n",
- smp_processor_id(), mcgsth, mcgstl);
-
for (i=0; i<nr_mce_banks; i++) {
+ m.bank = i;
+ m.tsc = 0;
+ m.stsl = m.stsh = 0;
+ m.addrl = m.addrh = 0;
+ m.miscl = m.misch = 0;
rdmsr (MSR_IA32_MC0_STATUS+i*4,low, high);
if (high & (1<<31)) {
if (high & (1<<29))
recover |= 1;
if (high & (1<<25))
recover |= 2;
- printk (KERN_EMERG "Bank %d: %08x%08x", i, high, low);
+ m.stsl = low;
+ m.stsh = high;
high &= ~(1<<31);
- if (high & (1<<27)) {
- rdmsr (MSR_IA32_MC0_MISC+i*4, alow, ahigh);
- printk ("[%08x%08x]", ahigh, alow);
+ if (high & (1<<27))
+ rdmsr (MSR_IA32_MC0_MISC+i*4, m.miscl, m.misch);
+ if (high & (1<<26))
+ rdmsr (MSR_IA32_MC0_ADDR+i*4, m.addrl, m.addrh);
+
+ /* Error at %eip ? */
+ if (m.mcgstl & (1<<1)) {
+ m.eip = regs->eip;
+ m.cs = regs->xcs;
+ } else {
+ m.eip = 0;
+ m.cs = 0;
}
- if (high & (1<<26)) {
- rdmsr (MSR_IA32_MC0_ADDR+i*4, alow, ahigh);
- printk (" at %08x%08x", ahigh, alow);
+
+ rdtscll(m.tsc);
+ mce_log(&m);
+ if (recover) {
+ panicm = m;
+ panicm_found = 1;
}
- printk ("\n");
}
}

+ if (!panicm_found)
+ panicm = m;
+
if (recover & 2)
- panic ("CPU context corrupt");
+ mce_panic ("CPU context corrupt", &panicm, mcestart);
if (recover & 1)
- panic ("Unable to continue");
+ mce_panic ("Unable to continue", &panicm, mcestart);

- printk (KERN_EMERG "Attempting to continue.\n");
/*
* Do not clear the MSR_IA32_MCi_STATUS if the error is not
* recoverable/continuable.This will allow BIOS to look at the MSRs
@@ -75,8 +95,8 @@ static asmlinkage void intel_machine_che
add_taint(TAINT_MACHINE_CHECK);
}
}
- mcgstl &= ~(1<<2);
- wrmsr (MSR_IA32_MCG_STATUS,mcgstl, mcgsth);
+ wrmsr (MSR_IA32_MCG_STATUS, m.mcgstl & ~(1 << 2), m.mcgsth);
+ mce_dump();
}

/* Set up machine check reporting for processors with Intel style MCE */
-
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