arch/x86/kernel/cpu/mce/threshold.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Common corrected MCE threshold handler code:
   4  */
   5 #include <linux/interrupt.h>
   6 #include <linux/kernel.h>
   7
   8 #include <asm/irq_vectors.h>
   9 #include <asm/traps.h>
  10 #include <asm/apic.h>
  11 #include <asm/mce.h>
  12 #include <asm/trace/irq_vectors.h>
  13
  14 #include "internal.h"
  15
  16 static void default_threshold_interrupt(void)
  17 {
  18         pr_err("Unexpected threshold interrupt at vector %x\n",
  19                 THRESHOLD_APIC_VECTOR);
  20 }
  21
  22 void (*mce_threshold_vector)(void) = default_threshold_interrupt;
  23
  24 DEFINE_IDTENTRY_SYSVEC(sysvec_threshold)
  25 {
  26         trace_threshold_apic_entry(THRESHOLD_APIC_VECTOR);
  27         inc_irq_stat(irq_threshold_count);
  28         mce_threshold_vector();
  29         trace_threshold_apic_exit(THRESHOLD_APIC_VECTOR);
  30         apic_eoi();
  31 }
  32
  33 DEFINE_PER_CPU(struct mca_storm_desc, storm_desc);
  34
  35 void mce_inherit_storm(unsigned int bank)
  36 {
  37         struct mca_storm_desc *storm = this_cpu_ptr(&storm_desc);
  38
  39         /*
  40          * Previous CPU owning this bank had put it into storm mode,
  41          * but the precise history of that storm is unknown. Assume
  42          * the worst (all recent polls of the bank found a valid error
  43          * logged). This will avoid the new owner prematurely declaring
  44          * the storm has ended.
  45          */
  46         storm->banks[bank].history = ~0ull;
  47         storm->banks[bank].timestamp = jiffies;
  48 }
  49
  50 bool mce_get_storm_mode(void)
  51 {
  52         return __this_cpu_read(storm_desc.poll_mode);
  53 }
  54
  55 void mce_set_storm_mode(bool storm)
  56 {
  57         __this_cpu_write(storm_desc.poll_mode, storm);
  58 }
  59
  60 static void mce_handle_storm(unsigned int bank, bool on)
  61 {
  62         switch (boot_cpu_data.x86_vendor) {
  63         case X86_VENDOR_INTEL:
  64                 mce_intel_handle_storm(bank, on);
  65                 break;
  66         }
  67 }
  68
  69 void cmci_storm_begin(unsigned int bank)
  70 {
  71         struct mca_storm_desc *storm = this_cpu_ptr(&storm_desc);
  72
  73         __set_bit(bank, this_cpu_ptr(mce_poll_banks));
  74         storm->banks[bank].in_storm_mode = true;
  75
  76         /*
  77          * If this is the first bank on this CPU to enter storm mode
  78          * start polling.
  79          */
  80         if (++storm->stormy_bank_count == 1)
  81                 mce_timer_kick(true);
  82 }
  83
  84 void cmci_storm_end(unsigned int bank)
  85 {
  86         struct mca_storm_desc *storm = this_cpu_ptr(&storm_desc);
  87
  88         __clear_bit(bank, this_cpu_ptr(mce_poll_banks));
  89         storm->banks[bank].history = 0;
  90         storm->banks[bank].in_storm_mode = false;
  91
  92         /* If no banks left in storm mode, stop polling. */
  93         if (!this_cpu_dec_return(storm_desc.stormy_bank_count))
  94                 mce_timer_kick(false);
  95 }
  96
  97 void mce_track_storm(struct mce *mce)
  98 {
  99         struct mca_storm_desc *storm = this_cpu_ptr(&storm_desc);
 100         unsigned long now = jiffies, delta;
 101         unsigned int shift = 1;
 102         u64 history = 0;
 103
 104         /* No tracking needed for banks that do not support CMCI */
 105         if (storm->banks[mce->bank].poll_only)
 106                 return;
 107
 108         /*
 109          * When a bank is in storm mode it is polled once per second and
 110          * the history mask will record about the last minute of poll results.
 111          * If it is not in storm mode, then the bank is only checked when
 112          * there is a CMCI interrupt. Check how long it has been since
 113          * this bank was last checked, and adjust the amount of "shift"
 114          * to apply to history.
 115          */
 116         if (!storm->banks[mce->bank].in_storm_mode) {
 117                 delta = now - storm->banks[mce->bank].timestamp;
 118                 shift = (delta + HZ) / HZ;
 119         }
 120
 121         /* If it has been a long time since the last poll, clear history. */
 122         if (shift < NUM_HISTORY_BITS)
 123                 history = storm->banks[mce->bank].history << shift;
 124
 125         storm->banks[mce->bank].timestamp = now;
 126
 127         /* History keeps track of corrected errors. VAL=1 && UC=0 */
 128         if ((mce->status & MCI_STATUS_VAL) && mce_is_correctable(mce))
 129                 history |= 1;
 130
 131         storm->banks[mce->bank].history = history;
 132
 133         if (storm->banks[mce->bank].in_storm_mode) {
 134                 if (history & GENMASK_ULL(STORM_END_POLL_THRESHOLD, 0))
 135                         return;
 136                 printk_deferred(KERN_NOTICE "CPU%d BANK%d CMCI storm subsided\n", smp_processor_id(), mce->bank);
 137                 mce_handle_storm(mce->bank, false);
 138                 cmci_storm_end(mce->bank);
 139         } else {
 140                 if (hweight64(history) < STORM_BEGIN_THRESHOLD)
 141                         return;
 142                 printk_deferred(KERN_NOTICE "CPU%d BANK%d CMCI storm detected\n", smp_processor_id(), mce->bank);
 143                 mce_handle_storm(mce->bank, true);
 144                 cmci_storm_begin(mce->bank);
 145         }
 146 }