RAS queue

index e4cf6ff1c2e1..b887415652ed 100644
@@ -123,8 +123,8 @@ void mce_setup(struct mce *m)
 {
 	memset(m, 0, sizeof(struct mce));
 	m->cpu = m->extcpu = smp_processor_id();
-	/* We hope get_seconds stays lockless */
-	m->time = get_seconds();
+	/* need the internal __ version to avoid deadlocks */
+	m->time = __ktime_get_real_seconds();
 	m->cpuvendor = boot_cpu_data.x86_vendor;
 	m->cpuid = cpuid_eax(1);
 	m->socketid = cpu_data(m->extcpu).phys_proc_id;

index b887415652ed..c3d08a69194d 100644
@@ -1205,13 +1205,18 @@ void do_machine_check(struct pt_regs *regs, long error_code)
 		lmce = m.mcgstatus & MCG_STATUS_LMCES;
 
 	/*
+	 * Local machine check may already know that we have to panic.
+	 * Broadcast machine check begins rendezvous in mce_start()
 	 * Go through all banks in exclusion of the other CPUs. This way we
 	 * don't report duplicated events on shared banks because the first one
-	 * to see it will clear it. If this is a Local MCE, then no need to
-	 * perform rendezvous.
+	 * to see it will clear it.
 	 */
-	if (!lmce)
+	if (lmce) {
+		if (no_way_out)
+			mce_panic("Fatal local machine check", &m, msg);
+	} else {
 		order = mce_start(&no_way_out);
+	}
 
 	for (i = 0; i < cfg->banks; i++) {
 		__clear_bit(i, toclear);

@@ -1287,12 +1292,17 @@ void do_machine_check(struct pt_regs *regs, long error_code)
 			no_way_out = worst >= MCE_PANIC_SEVERITY;
 	} else {
 		/*
-		 * Local MCE skipped calling mce_reign()
-		 * If we found a fatal error, we need to panic here.
+		 * If there was a fatal machine check we should have
+		 * already called mce_panic earlier in this function.
+		 * Since we re-read the banks, we might have found
+		 * something new. Check again to see if we found a
+		 * fatal error. We call "mce_severity()" again to
+		 * make sure we have the right "msg".
 		 */
-		 if (worst >= MCE_PANIC_SEVERITY && mca_cfg.tolerant < 3)
-			mce_panic("Machine check from unknown source",
-				NULL, NULL);
+		if (worst >= MCE_PANIC_SEVERITY && mca_cfg.tolerant < 3) {
+			mce_severity(&m, cfg->tolerant, &msg, true);
+			mce_panic("Local fatal machine check!", &m, msg);
+		}
 	}
 
 	/*

index c3d08a69194d..ea1521ec7e5b 100644
@@ -1102,6 +1102,34 @@ static void mce_unmap_kpfn(unsigned long pfn)
 }
 #endif
 
+
+/*
+ * Cases where we avoid rendezvous handler timeout:
+ * 1) If this CPU is offline.
+ *
+ * 2) If crashing_cpu was set, e.g. we're entering kdump and we need to
+ *  skip those CPUs which remain looping in the 1st kernel - see
+ *  crash_nmi_callback().
+ *
+ * Note: there still is a small window between kexec-ing and the new,
+ * kdump kernel establishing a new #MC handler where a broadcasted MCE
+ * might not get handled properly.
+ */
+static bool __mc_check_crashing_cpu(int cpu)
+{
+	if (cpu_is_offline(cpu) ||
+	    (crashing_cpu != -1 && crashing_cpu != cpu)) {
+		u64 mcgstatus;
+
+		mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS);
+		if (mcgstatus & MCG_STATUS_RIPV) {
+			mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);
+			return true;
+		}
+	}
+	return false;
+}
+
 /*
  * The actual machine check handler. This only handles real
  * exceptions when something got corrupted coming in through int 18.

@@ -1116,60 +1144,42 @@ static void mce_unmap_kpfn(unsigned long pfn)
  */
 void do_machine_check(struct pt_regs *regs, long error_code)
 {
+	DECLARE_BITMAP(valid_banks, MAX_NR_BANKS);
+	DECLARE_BITMAP(toclear, MAX_NR_BANKS);
 	struct mca_config *cfg = &mca_cfg;
+	int cpu = smp_processor_id();
+	char *msg = "Unknown";
 	struct mce m, *final;
-	int i;
 	int worst = 0;
 	int severity;
+	int i;
 
 	/*
 	 * Establish sequential order between the CPUs entering the machine
 	 * check handler.
 	 */
 	int order = -1;
+
 	/*
 	 * If no_way_out gets set, there is no safe way to recover from this
 	 * MCE.  If mca_cfg.tolerant is cranked up, we'll try anyway.
 	 */
 	int no_way_out = 0;
+
 	/*
 	 * If kill_it gets set, there might be a way to recover from this
 	 * error.
 	 */
 	int kill_it = 0;
-	DECLARE_BITMAP(toclear, MAX_NR_BANKS);
-	DECLARE_BITMAP(valid_banks, MAX_NR_BANKS);
-	char *msg = "Unknown";
 
 	/*
 	 * MCEs are always local on AMD. Same is determined by MCG_STATUS_LMCES
 	 * on Intel.
 	 */
 	int lmce = 1;
-	int cpu = smp_processor_id();
-
-	/*
-	 * Cases where we avoid rendezvous handler timeout:
-	 * 1) If this CPU is offline.
-	 *
-	 * 2) If crashing_cpu was set, e.g. we're entering kdump and we need to
-	 *  skip those CPUs which remain looping in the 1st kernel - see
-	 *  crash_nmi_callback().
-	 *
-	 * Note: there still is a small window between kexec-ing and the new,
-	 * kdump kernel establishing a new #MC handler where a broadcasted MCE
-	 * might not get handled properly.
-	 */
-	if (cpu_is_offline(cpu) ||
-	    (crashing_cpu != -1 && crashing_cpu != cpu)) {
-		u64 mcgstatus;
 
-		mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS);
-		if (mcgstatus & MCG_STATUS_RIPV) {
-			mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);
-			return;
-		}
-	}
+	if (__mc_check_crashing_cpu(cpu))
+		return;
 
 	ist_enter(regs);
 

index ea1521ec7e5b..05d2d15a95bd 100644
@@ -1185,9 +1185,6 @@ void do_machine_check(struct pt_regs *regs, long error_code)
 
 	this_cpu_inc(mce_exception_count);
 
-	if (!cfg->banks)
-		goto out;
-
 	mce_gather_info(&m, regs);
 	m.tsc = rdtsc();
 

@@ -1327,7 +1324,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
 	if (worst > 0)
 		mce_report_event(regs);
 	mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);
-out:
+
 	sync_core();
 
 	if (worst != MCE_AR_SEVERITY && !kill_it)

index 05d2d15a95bd..5e834bad4eaf 100644
@@ -1130,6 +1130,76 @@ static bool __mc_check_crashing_cpu(int cpu)
 	return false;
 }
 
+static void __mc_scan_banks(struct mce *m, struct mce *final,
+			    unsigned long *toclear, unsigned long *valid_banks,
+			    int no_way_out, int *worst)
+{
+	struct mca_config *cfg = &mca_cfg;
+	int severity, i;
+
+	for (i = 0; i < cfg->banks; i++) {
+		__clear_bit(i, toclear);
+		if (!test_bit(i, valid_banks))
+			continue;
+		if (!mce_banks[i].ctl)
+			continue;
+
+		m->misc = 0;
+		m->addr = 0;
+		m->bank = i;
+
+		m->status = mce_rdmsrl(msr_ops.status(i));
+		if ((m->status & MCI_STATUS_VAL) == 0)
+			continue;
+
+		/*
+		 * Non uncorrected or non signaled errors are handled by
+		 * machine_check_poll. Leave them alone, unless this panics.
+		 */
+		if (!(m->status & (cfg->ser ? MCI_STATUS_S : MCI_STATUS_UC)) &&
+			!no_way_out)
+			continue;
+
+		/*
+		 * Set taint even when machine check was not enabled.
+		 */
+		add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
+
+		severity = mce_severity(m, cfg->tolerant, NULL, true);
+
+		/*
+		 * When machine check was for corrected/deferred handler don't
+		 * touch, unless we're panicing.
+		 */
+		if ((severity == MCE_KEEP_SEVERITY ||
+		     severity == MCE_UCNA_SEVERITY) && !no_way_out)
+			continue;
+		__set_bit(i, toclear);
+		if (severity == MCE_NO_SEVERITY) {
+			/*
+			 * Machine check event was not enabled. Clear, but
+			 * ignore.
+			 */
+			continue;
+		}
+
+		mce_read_aux(m, i);
+
+		/* assuming valid severity level != 0 */
+		m->severity = severity;
+
+		mce_log(m);
+
+		if (severity > *worst) {
+			*final = *m;
+			*worst = severity;
+		}
+	}
+
+	/* mce_clear_state will clear *final, save locally for use later */
+	*m = *final;
+}
+
 /*
  * The actual machine check handler. This only handles real
  * exceptions when something got corrupted coming in through int 18.

@@ -1151,8 +1221,6 @@ void do_machine_check(struct pt_regs *regs, long error_code)
 	char *msg = "Unknown";
 	struct mce m, *final;
 	int worst = 0;
-	int severity;
-	int i;
 
 	/*
 	 * Establish sequential order between the CPUs entering the machine

@@ -1225,67 +1293,7 @@ void do_machine_check(struct pt_regs *regs, long error_code)
 		order = mce_start(&no_way_out);
 	}
 
-	for (i = 0; i < cfg->banks; i++) {
-		__clear_bit(i, toclear);
-		if (!test_bit(i, valid_banks))
-			continue;
-		if (!mce_banks[i].ctl)
-			continue;
-
-		m.misc = 0;
-		m.addr = 0;
-		m.bank = i;
-
-		m.status = mce_rdmsrl(msr_ops.status(i));
-		if ((m.status & MCI_STATUS_VAL) == 0)
-			continue;
-
-		/*
-		 * Non uncorrected or non signaled errors are handled by
-		 * machine_check_poll. Leave them alone, unless this panics.
-		 */
-		if (!(m.status & (cfg->ser ? MCI_STATUS_S : MCI_STATUS_UC)) &&
-			!no_way_out)
-			continue;
-
-		/*
-		 * Set taint even when machine check was not enabled.
-		 */
-		add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
-
-		severity = mce_severity(&m, cfg->tolerant, NULL, true);
-
-		/*
-		 * When machine check was for corrected/deferred handler don't
-		 * touch, unless we're panicing.
-		 */
-		if ((severity == MCE_KEEP_SEVERITY ||
-		     severity == MCE_UCNA_SEVERITY) && !no_way_out)
-			continue;
-		__set_bit(i, toclear);
-		if (severity == MCE_NO_SEVERITY) {
-			/*
-			 * Machine check event was not enabled. Clear, but
-			 * ignore.
-			 */
-			continue;
-		}
-
-		mce_read_aux(&m, i);
-
-		/* assuming valid severity level != 0 */
-		m.severity = severity;
-
-		mce_log(&m);
-
-		if (severity > worst) {
-			*final = m;
-			worst = severity;
-		}
-	}
-
-	/* mce_clear_state will clear *final, save locally for use later */
-	m = *final;
+	__mc_scan_banks(&m, final, toclear, valid_banks, no_way_out, &worst);
 
 	if (!no_way_out)
 		mce_clear_state(toclear);

index 5e834bad4eaf..5c38d1f861f2 100644
@@ -1141,6 +1141,7 @@ static void __mc_scan_banks(struct mce *m, struct mce *final,
 		__clear_bit(i, toclear);
 		if (!test_bit(i, valid_banks))
 			continue;
+
 		if (!mce_banks[i].ctl)
 			continue;
 

@@ -1149,39 +1150,35 @@ static void __mc_scan_banks(struct mce *m, struct mce *final,
 		m->bank = i;
 
 		m->status = mce_rdmsrl(msr_ops.status(i));
-		if ((m->status & MCI_STATUS_VAL) == 0)
+		if (!(m->status & MCI_STATUS_VAL))
 			continue;
 
 		/*
-		 * Non uncorrected or non signaled errors are handled by
-		 * machine_check_poll. Leave them alone, unless this panics.
+		 * Corrected or non-signaled errors are handled by
+		 * machine_check_poll(). Leave them alone, unless this panics.
 		 */
 		if (!(m->status & (cfg->ser ? MCI_STATUS_S : MCI_STATUS_UC)) &&
 			!no_way_out)
 			continue;
 
-		/*
-		 * Set taint even when machine check was not enabled.
-		 */
+		/* Set taint even when machine check was not enabled. */
 		add_taint(TAINT_MACHINE_CHECK, LOCKDEP_NOW_UNRELIABLE);
 
 		severity = mce_severity(m, cfg->tolerant, NULL, true);
 
 		/*
 		 * When machine check was for corrected/deferred handler don't
-		 * touch, unless we're panicing.
+		 * touch, unless we're panicking.
 		 */
 		if ((severity == MCE_KEEP_SEVERITY ||
 		     severity == MCE_UCNA_SEVERITY) && !no_way_out)
 			continue;
+
 		__set_bit(i, toclear);
-		if (severity == MCE_NO_SEVERITY) {
-			/*
-			 * Machine check event was not enabled. Clear, but
-			 * ignore.
-			 */
+
+		/* Machine check event was not enabled. Clear, but ignore. */
+		if (severity == MCE_NO_SEVERITY)
 			continue;
-		}
 
 		mce_read_aux(m, i);
 

index 5c38d1f861f2..9a16f15f79eb 100644
@@ -772,23 +772,25 @@ EXPORT_SYMBOL_GPL(machine_check_poll);
 static int mce_no_way_out(struct mce *m, char **msg, unsigned long *validp,
 			  struct pt_regs *regs)
 {
-	int i, ret = 0;
 	char *tmp;
+	int i;
 
 	for (i = 0; i < mca_cfg.banks; i++) {
 		m->status = mce_rdmsrl(msr_ops.status(i));
-		if (m->status & MCI_STATUS_VAL) {
-			__set_bit(i, validp);
-			if (quirk_no_way_out)
-				quirk_no_way_out(i, m, regs);
-		}
+		if (!(m->status & MCI_STATUS_VAL))
+			continue;
+
+		__set_bit(i, validp);
+		if (quirk_no_way_out)
+			quirk_no_way_out(i, m, regs);
 
 		if (mce_severity(m, mca_cfg.tolerant, &tmp, true) >= MCE_PANIC_SEVERITY) {
+			mce_read_aux(m, i);
 			*msg = tmp;
-			ret = 1;
+			return 1;
 		}
 	}
-	return ret;
+	return 0;
 }
 
 /*