1 files changed, 115 insertions, 0 deletions

diff --git a/arch/x86/kernel/cpu/mce/threshold.c b/arch/x86/kernel/cpu/mce/threshold.c
index ef4e7bb5fd88..89e31e1e5c9c 100644
--- a/arch/x86/kernel/cpu/mce/threshold.c
+++ b/arch/x86/kernel/cpu/mce/threshold.c
@@ -29,3 +29,118 @@ DEFINE_IDTENTRY_SYSVEC(sysvec_threshold)
 	trace_threshold_apic_exit(THRESHOLD_APIC_VECTOR);
 	apic_eoi();
 }
+
+DEFINE_PER_CPU(struct mca_storm_desc, storm_desc);
+
+void mce_inherit_storm(unsigned int bank)
+{
+	struct mca_storm_desc *storm = this_cpu_ptr(&storm_desc);
+
+	/*
+	 * Previous CPU owning this bank had put it into storm mode,
+	 * but the precise history of that storm is unknown. Assume
+	 * the worst (all recent polls of the bank found a valid error
+	 * logged). This will avoid the new owner prematurely declaring
+	 * the storm has ended.
+	 */
+	storm->banks[bank].history = ~0ull;
+	storm->banks[bank].timestamp = jiffies;
+}
+
+bool mce_get_storm_mode(void)
+{
+	return __this_cpu_read(storm_desc.poll_mode);
+}
+
+void mce_set_storm_mode(bool storm)
+{
+	__this_cpu_write(storm_desc.poll_mode, storm);
+}
+
+static void mce_handle_storm(unsigned int bank, bool on)
+{
+	switch (boot_cpu_data.x86_vendor) {
+	case X86_VENDOR_INTEL:
+		mce_intel_handle_storm(bank, on);
+		break;
+	}
+}
+
+void cmci_storm_begin(unsigned int bank)
+{
+	struct mca_storm_desc *storm = this_cpu_ptr(&storm_desc);
+
+	__set_bit(bank, this_cpu_ptr(mce_poll_banks));
+	storm->banks[bank].in_storm_mode = true;
+
+	/*
+	 * If this is the first bank on this CPU to enter storm mode
+	 * start polling.
+	 */
+	if (++storm->stormy_bank_count == 1)
+		mce_timer_kick(true);
+}
+
+void cmci_storm_end(unsigned int bank)
+{
+	struct mca_storm_desc *storm = this_cpu_ptr(&storm_desc);
+
+	__clear_bit(bank, this_cpu_ptr(mce_poll_banks));
+	storm->banks[bank].history = 0;
+	storm->banks[bank].in_storm_mode = false;
+
+	/* If no banks left in storm mode, stop polling. */
+	if (!this_cpu_dec_return(storm_desc.stormy_bank_count))
+		mce_timer_kick(false);
+}
+
+void mce_track_storm(struct mce *mce)
+{
+	struct mca_storm_desc *storm = this_cpu_ptr(&storm_desc);
+	unsigned long now = jiffies, delta;
+	unsigned int shift = 1;
+	u64 history = 0;
+
+	/* No tracking needed for banks that do not support CMCI */
+	if (storm->banks[mce->bank].poll_only)
+		return;
+
+	/*
+	 * When a bank is in storm mode it is polled once per second and
+	 * the history mask will record about the last minute of poll results.
+	 * If it is not in storm mode, then the bank is only checked when
+	 * there is a CMCI interrupt. Check how long it has been since
+	 * this bank was last checked, and adjust the amount of "shift"
+	 * to apply to history.
+	 */
+	if (!storm->banks[mce->bank].in_storm_mode) {
+		delta = now - storm->banks[mce->bank].timestamp;
+		shift = (delta + HZ) / HZ;
+	}
+
+	/* If it has been a long time since the last poll, clear history. */
+	if (shift < NUM_HISTORY_BITS)
+		history = storm->banks[mce->bank].history << shift;
+
+	storm->banks[mce->bank].timestamp = now;
+
+	/* History keeps track of corrected errors. VAL=1 && UC=0 */
+	if ((mce->status & MCI_STATUS_VAL) && mce_is_correctable(mce))
+		history |= 1;
+
+	storm->banks[mce->bank].history = history;
+
+	if (storm->banks[mce->bank].in_storm_mode) {
+		if (history & GENMASK_ULL(STORM_END_POLL_THRESHOLD, 0))
+			return;
+		printk_deferred(KERN_NOTICE "CPU%d BANK%d CMCI storm subsided\n", smp_processor_id(), mce->bank);
+		mce_handle_storm(mce->bank, false);
+		cmci_storm_end(mce->bank);
+	} else {
+		if (hweight64(history) < STORM_BEGIN_THRESHOLD)
+			return;
+		printk_deferred(KERN_NOTICE "CPU%d BANK%d CMCI storm detected\n", smp_processor_id(), mce->bank);
+		mce_handle_storm(mce->bank, true);
+		cmci_storm_begin(mce->bank);
+	}
+}