Merge tag 'ras_core_for_v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 RAS updates from Borislav Petkov:

- Convert the hw error storm handling into a finer-grained, per-bank
solution which allows for more timely detection and reporting of
errors

- Start a documentation section which will hold down relevant RAS
features description and how they should be used

- Add new AMD error bank types

- Slim down and remove error type descriptions from the kernel side of
error decoding to rasdaemon which can be used from now on to decode
hw errors on AMD

- Mark pages containing uncorrectable errors as poison so that kdump
can avoid them and thus not cause another panic

- The usual cleanups and fixlets

* tag 'ras_core_for_v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/mce: Handle Intel threshold interrupt storms
x86/mce: Add per-bank CMCI storm mitigation
x86/mce: Remove old CMCI storm mitigation code
Documentation: Begin a RAS section
x86/MCE/AMD: Add new MA_LLC, USR_DP, and USR_CP bank types
EDAC/mce_amd: Remove SMCA Extended Error code descriptions
x86/mce/amd, EDAC/mce_amd: Move long names to decoder module
x86/mce/inject: Clear test status value
x86/mce: Remove redundant check from mce_device_create()
x86/mce: Mark fatal MCE's page as poison to avoid panic in the kdump kernel

Documentation/RAS/ras.rst

···
+.. SPDX-License-Identifier: GPL-2.0
+
+Reliability, Availability and Serviceability features
+=====================================================
+
+This documents different aspects of the RAS functionality present in the
+kernel.
+
+Error decoding
+---------------
+
+* x86
+
+Error decoding on AMD systems should be done using the rasdaemon tool:
+https://github.com/mchehab/rasdaemon/
+
+While the daemon is running, it would automatically log and decode
+errors. If not, one can still decode such errors by supplying the
+hardware information from the error::
+
+        $ rasdaemon -p --status <STATUS> --ipid <IPID> --smca
+
+Also, the user can pass particular family and model to decode the error
+string::
+
+        $ rasdaemon -p --status <STATUS> --ipid <IPID> --smca --family <CPU Family> --model <CPU Model> --bank <BANK_NUM>

Documentation/index.rst

···
    :maxdepth: 1
 
    staging/index
+   RAS/ras
 
 
 Translations

arch/x86/include/asm/mce.h

···
 	SMCA_PIE,	/* Power, Interrupts, etc. */
 	SMCA_UMC,	/* Unified Memory Controller */
 	SMCA_UMC_V2,
+	SMCA_MA_LLC,	/* Memory Attached Last Level Cache */
 	SMCA_PB,	/* Parameter Block */
 	SMCA_PSP,	/* Platform Security Processor */
 	SMCA_PSP_V2,
···
 	SMCA_SHUB,	/* System HUB Unit */
 	SMCA_SATA,	/* SATA Unit */
 	SMCA_USB,	/* USB Unit */
+	SMCA_USR_DP,	/* Ultra Short Reach Data Plane Controller */
+	SMCA_USR_CP,	/* Ultra Short Reach Control Plane Controller */
 	SMCA_GMI_PCS,	/* GMI PCS Unit */
 	SMCA_XGMI_PHY,	/* xGMI PHY Unit */
 	SMCA_WAFL_PHY,	/* WAFL PHY Unit */
···
 	N_SMCA_BANK_TYPES
 };
 
-extern const char *smca_get_long_name(enum smca_bank_types t);
 extern bool amd_mce_is_memory_error(struct mce *m);
 
 extern int mce_threshold_create_device(unsigned int cpu);

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

···
 static DEFINE_PER_CPU_READ_MOSTLY(struct smca_bank[MAX_NR_BANKS], smca_banks);
 static DEFINE_PER_CPU_READ_MOSTLY(u8[N_SMCA_BANK_TYPES], smca_bank_counts);
 
-struct smca_bank_name {
-	const char *name;	/* Short name for sysfs */
-	const char *long_name;	/* Long name for pretty-printing */
-};
-
-static struct smca_bank_name smca_names[] = {
-	[SMCA_LS ... SMCA_LS_V2]	= { "load_store",	"Load Store Unit" },
-	[SMCA_IF]			= { "insn_fetch",	"Instruction Fetch Unit" },
-	[SMCA_L2_CACHE]			= { "l2_cache",		"L2 Cache" },
-	[SMCA_DE]			= { "decode_unit",	"Decode Unit" },
-	[SMCA_RESERVED]			= { "reserved",		"Reserved" },
-	[SMCA_EX]			= { "execution_unit",	"Execution Unit" },
-	[SMCA_FP]			= { "floating_point",	"Floating Point Unit" },
-	[SMCA_L3_CACHE]			= { "l3_cache",		"L3 Cache" },
-	[SMCA_CS ... SMCA_CS_V2]	= { "coherent_slave",	"Coherent Slave" },
-	[SMCA_PIE]			= { "pie",		"Power, Interrupts, etc." },
+static const char * const smca_names[] = {
+	[SMCA_LS ... SMCA_LS_V2]	= "load_store",
+	[SMCA_IF]			= "insn_fetch",
+	[SMCA_L2_CACHE]			= "l2_cache",
+	[SMCA_DE]			= "decode_unit",
+	[SMCA_RESERVED]			= "reserved",
+	[SMCA_EX]			= "execution_unit",
+	[SMCA_FP]			= "floating_point",
+	[SMCA_L3_CACHE]			= "l3_cache",
+	[SMCA_CS ... SMCA_CS_V2]	= "coherent_slave",
+	[SMCA_PIE]			= "pie",
 
 	/* UMC v2 is separate because both of them can exist in a single system. */
-	[SMCA_UMC]			= { "umc",		"Unified Memory Controller" },
-	[SMCA_UMC_V2]			= { "umc_v2",		"Unified Memory Controller v2" },
-	[SMCA_PB]			= { "param_block",	"Parameter Block" },
-	[SMCA_PSP ... SMCA_PSP_V2]	= { "psp",		"Platform Security Processor" },
-	[SMCA_SMU ... SMCA_SMU_V2]	= { "smu",		"System Management Unit" },
-	[SMCA_MP5]			= { "mp5",		"Microprocessor 5 Unit" },
-	[SMCA_MPDMA]			= { "mpdma",		"MPDMA Unit" },
-	[SMCA_NBIO]			= { "nbio",		"Northbridge IO Unit" },
-	[SMCA_PCIE ... SMCA_PCIE_V2]	= { "pcie",		"PCI Express Unit" },
-	[SMCA_XGMI_PCS]			= { "xgmi_pcs",		"Ext Global Memory Interconnect PCS Unit" },
-	[SMCA_NBIF]			= { "nbif",		"NBIF Unit" },
-	[SMCA_SHUB]			= { "shub",		"System Hub Unit" },
-	[SMCA_SATA]			= { "sata",		"SATA Unit" },
-	[SMCA_USB]			= { "usb",		"USB Unit" },
-	[SMCA_GMI_PCS]			= { "gmi_pcs",		"Global Memory Interconnect PCS Unit" },
-	[SMCA_XGMI_PHY]			= { "xgmi_phy",		"Ext Global Memory Interconnect PHY Unit" },
-	[SMCA_WAFL_PHY]			= { "wafl_phy",		"WAFL PHY Unit" },
-	[SMCA_GMI_PHY]			= { "gmi_phy",		"Global Memory Interconnect PHY Unit" },
+	[SMCA_UMC]			= "umc",
+	[SMCA_UMC_V2]			= "umc_v2",
+	[SMCA_MA_LLC]			= "ma_llc",
+	[SMCA_PB]			= "param_block",
+	[SMCA_PSP ... SMCA_PSP_V2]	= "psp",
+	[SMCA_SMU ... SMCA_SMU_V2]	= "smu",
+	[SMCA_MP5]			= "mp5",
+	[SMCA_MPDMA]			= "mpdma",
+	[SMCA_NBIO]			= "nbio",
+	[SMCA_PCIE ... SMCA_PCIE_V2]	= "pcie",
+	[SMCA_XGMI_PCS]			= "xgmi_pcs",
+	[SMCA_NBIF]			= "nbif",
+	[SMCA_SHUB]			= "shub",
+	[SMCA_SATA]			= "sata",
+	[SMCA_USB]			= "usb",
+	[SMCA_USR_DP]			= "usr_dp",
+	[SMCA_USR_CP]			= "usr_cp",
+	[SMCA_GMI_PCS]			= "gmi_pcs",
+	[SMCA_XGMI_PHY]			= "xgmi_phy",
+	[SMCA_WAFL_PHY]			= "wafl_phy",
+	[SMCA_GMI_PHY]			= "gmi_phy",
 };
 
 static const char *smca_get_name(enum smca_bank_types t)
···
 	if (t >= N_SMCA_BANK_TYPES)
 		return NULL;
 
-	return smca_names[t].name;
+	return smca_names[t];
 }
-
-const char *smca_get_long_name(enum smca_bank_types t)
-{
-	if (t >= N_SMCA_BANK_TYPES)
-		return NULL;
-
-	return smca_names[t].long_name;
-}
-EXPORT_SYMBOL_GPL(smca_get_long_name);
 
 enum smca_bank_types smca_get_bank_type(unsigned int cpu, unsigned int bank)
 {
···
 	{ SMCA_CS,	 HWID_MCATYPE(0x2E, 0x0)	},
 	{ SMCA_PIE,	 HWID_MCATYPE(0x2E, 0x1)	},
 	{ SMCA_CS_V2,	 HWID_MCATYPE(0x2E, 0x2)	},
+	{ SMCA_MA_LLC,	 HWID_MCATYPE(0x2E, 0x4)	},
 
 	/* Unified Memory Controller MCA type */
 	{ SMCA_UMC,	 HWID_MCATYPE(0x96, 0x0)	},
···
 	{ SMCA_SHUB,	 HWID_MCATYPE(0x80, 0x0)	},
 	{ SMCA_SATA,	 HWID_MCATYPE(0xA8, 0x0)	},
 	{ SMCA_USB,	 HWID_MCATYPE(0xAA, 0x0)	},
+	{ SMCA_USR_DP,	 HWID_MCATYPE(0x170, 0x0)	},
+	{ SMCA_USR_CP,	 HWID_MCATYPE(0x180, 0x0)	},
 	{ SMCA_GMI_PCS,  HWID_MCATYPE(0x241, 0x0)	},
 	{ SMCA_XGMI_PHY, HWID_MCATYPE(0x259, 0x0)	},
 	{ SMCA_WAFL_PHY, HWID_MCATYPE(0x267, 0x0)	},

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

···
 #include <linux/sync_core.h>
 #include <linux/task_work.h>
 #include <linux/hardirq.h>
+#include <linux/kexec.h>
 
 #include <asm/intel-family.h>
 #include <asm/processor.h>
···
 	struct llist_node *pending;
 	struct mce_evt_llist *l;
 	int apei_err = 0;
+	struct page *p;
 
 	/*
 	 * Allow instrumentation around external facilities usage. Not that it
···
 	if (!fake_panic) {
 		if (panic_timeout == 0)
 			panic_timeout = mca_cfg.panic_timeout;
+
+		/*
+		 * Kdump skips the poisoned page in order to avoid
+		 * touching the error bits again. Poison the page even
+		 * if the error is fatal and the machine is about to
+		 * panic.
+		 */
+		if (kexec_crash_loaded()) {
+			if (final && (final->status & MCI_STATUS_ADDRV)) {
+				p = pfn_to_online_page(final->addr >> PAGE_SHIFT);
+				if (p)
+					SetPageHWPoison(p);
+			}
+		}
 		panic(msg);
 	} else
 		pr_emerg(HW_ERR "Fake kernel panic: %s\n", msg);
···
 
 		barrier();
 		m.status = mce_rdmsrl(mca_msr_reg(i, MCA_STATUS));
+
+		/*
+		 * Update storm tracking here, before checking for the
+		 * MCI_STATUS_VAL bit. Valid corrected errors count
+		 * towards declaring, or maintaining, storm status. No
+		 * error in a bank counts towards avoiding, or ending,
+		 * storm status.
+		 */
+		if (!mca_cfg.cmci_disabled)
+			mce_track_storm(&m);
 
 		/* If this entry is not valid, ignore it */
 		if (!(m.status & MCI_STATUS_VAL))
···
 static DEFINE_PER_CPU(unsigned long, mce_next_interval); /* in jiffies */
 static DEFINE_PER_CPU(struct timer_list, mce_timer);
 
-static unsigned long mce_adjust_timer_default(unsigned long interval)
-{
-	return interval;
-}
-
-static unsigned long (*mce_adjust_timer)(unsigned long interval) = mce_adjust_timer_default;
-
 static void __start_timer(struct timer_list *t, unsigned long interval)
 {
 	unsigned long when = jiffies + interval;
···
 
 	iv = __this_cpu_read(mce_next_interval);
 
-	if (mce_available(this_cpu_ptr(&cpu_info))) {
+	if (mce_available(this_cpu_ptr(&cpu_info)))
 		mc_poll_banks();
-
-		if (mce_intel_cmci_poll()) {
-			iv = mce_adjust_timer(iv);
-			goto done;
-		}
-	}
 
 	/*
 	 * Alert userspace if needed. If we logged an MCE, reduce the polling
···
 	else
 		iv = min(iv * 2, round_jiffies_relative(check_interval * HZ));
 
-done:
-	__this_cpu_write(mce_next_interval, iv);
-	__start_timer(t, iv);
+	if (mce_get_storm_mode()) {
+		__start_timer(t, HZ);
+	} else {
+		__this_cpu_write(mce_next_interval, iv);
+		__start_timer(t, iv);
+	}
 }
 
 /*
- * Ensure that the timer is firing in @interval from now.
+ * When a storm starts on any bank on this CPU, switch to polling
+ * once per second. When the storm ends, revert to the default
+ * polling interval.
  */
-void mce_timer_kick(unsigned long interval)
+void mce_timer_kick(bool storm)
 {
 	struct timer_list *t = this_cpu_ptr(&mce_timer);
-	unsigned long iv = __this_cpu_read(mce_next_interval);
 
-	__start_timer(t, interval);
+	mce_set_storm_mode(storm);
 
-	if (interval < iv)
-		__this_cpu_write(mce_next_interval, interval);
+	if (storm)
+		__start_timer(t, HZ);
+	else
+		__this_cpu_write(mce_next_interval, check_interval * HZ);
 }
 
 /* Must not be called in IRQ context where del_timer_sync() can deadlock */
···
 
 	intel_init_cmci();
 	intel_init_lmce();
-	mce_adjust_timer = cmci_intel_adjust_timer;
 }
 
 static void mce_zhaoxin_feature_clear(struct cpuinfo_x86 *c)
···
 	switch (c->x86_vendor) {
 	case X86_VENDOR_INTEL:
 		mce_intel_feature_init(c);
-		mce_adjust_timer = cmci_intel_adjust_timer;
 		break;
 
 	case X86_VENDOR_AMD: {
···
 	int err;
 	int i, j;
 
-	if (!mce_available(&boot_cpu_data))
-		return -EIO;
-
 	dev = per_cpu(mce_device, cpu);
 	if (dev)
 		return 0;
···
 
 static int mce_cpu_dead(unsigned int cpu)
 {
-	mce_intel_hcpu_update(cpu);
-
 	/* intentionally ignoring frozen here */
 	if (!cpuhp_tasks_frozen)
 		cmci_rediscover();

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

···
 
 		wrmsrl_safe(mca_msr_reg(bank, MCA_STATUS), status);
 		rdmsrl_safe(mca_msr_reg(bank, MCA_STATUS), &status);
+		wrmsrl_safe(mca_msr_reg(bank, MCA_STATUS), 0);
 
 		if (!status) {
 			hw_injection_possible = false;

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

···
 static DEFINE_PER_CPU(mce_banks_t, mce_banks_owned);
 
 /*
- * CMCI storm detection backoff counter
- *
- * During storm, we reset this counter to INITIAL_CHECK_INTERVAL in case we've
- * encountered an error. If not, we decrement it by one. We signal the end of
- * the CMCI storm when it reaches 0.
- */
-static DEFINE_PER_CPU(int, cmci_backoff_cnt);
-
-/*
  * cmci_discover_lock protects against parallel discovery attempts
  * which could race against each other.
  */
···
  */
 static DEFINE_SPINLOCK(cmci_poll_lock);
 
+/* Linux non-storm CMCI threshold (may be overridden by BIOS) */
 #define CMCI_THRESHOLD		1
-#define CMCI_POLL_INTERVAL	(30 * HZ)
-#define CMCI_STORM_INTERVAL	(HZ)
-#define CMCI_STORM_THRESHOLD	15
 
-static DEFINE_PER_CPU(unsigned long, cmci_time_stamp);
-static DEFINE_PER_CPU(unsigned int, cmci_storm_cnt);
-static DEFINE_PER_CPU(unsigned int, cmci_storm_state);
+/*
+ * MCi_CTL2 threshold for each bank when there is no storm.
+ * Default value for each bank may have been set by BIOS.
+ */
+static u16 cmci_threshold[MAX_NR_BANKS];
 
-enum {
-	CMCI_STORM_NONE,
-	CMCI_STORM_ACTIVE,
-	CMCI_STORM_SUBSIDED,
-};
-
-static atomic_t cmci_storm_on_cpus;
+/*
+ * High threshold to limit CMCI rate during storms. Max supported is
+ * 0x7FFF. Use this slightly smaller value so it has a distinctive
+ * signature when some asks "Why am I not seeing all corrected errors?"
+ * A high threshold is used instead of just disabling CMCI for a
+ * bank because both corrected and uncorrected errors may be logged
+ * in the same bank and signalled with CMCI. The threshold only applies
+ * to corrected errors, so keeping CMCI enabled means that uncorrected
+ * errors will still be processed in a timely fashion.
+ */
+#define CMCI_STORM_THRESHOLD	32749
 
 static int cmci_supported(int *banks)
 {
···
 	return tmp & FEAT_CTL_LMCE_ENABLED;
 }
 
-bool mce_intel_cmci_poll(void)
+/*
+ * Set a new CMCI threshold value. Preserve the state of the
+ * MCI_CTL2_CMCI_EN bit in case this happens during a
+ * cmci_rediscover() operation.
+ */
+static void cmci_set_threshold(int bank, int thresh)
 {
-	if (__this_cpu_read(cmci_storm_state) == CMCI_STORM_NONE)
-		return false;
-
-	/*
-	 * Reset the counter if we've logged an error in the last poll
-	 * during the storm.
-	 */
-	if (machine_check_poll(0, this_cpu_ptr(&mce_banks_owned)))
-		this_cpu_write(cmci_backoff_cnt, INITIAL_CHECK_INTERVAL);
-	else
-		this_cpu_dec(cmci_backoff_cnt);
-
-	return true;
-}
-
-void mce_intel_hcpu_update(unsigned long cpu)
-{
-	if (per_cpu(cmci_storm_state, cpu) == CMCI_STORM_ACTIVE)
-		atomic_dec(&cmci_storm_on_cpus);
-
-	per_cpu(cmci_storm_state, cpu) = CMCI_STORM_NONE;
-}
-
-static void cmci_toggle_interrupt_mode(bool on)
-{
-	unsigned long flags, *owned;
-	int bank;
+	unsigned long flags;
 	u64 val;
 
 	raw_spin_lock_irqsave(&cmci_discover_lock, flags);
-	owned = this_cpu_ptr(mce_banks_owned);
-	for_each_set_bit(bank, owned, MAX_NR_BANKS) {
-		rdmsrl(MSR_IA32_MCx_CTL2(bank), val);
-
-		if (on)
-			val |= MCI_CTL2_CMCI_EN;
-		else
-			val &= ~MCI_CTL2_CMCI_EN;
-
-		wrmsrl(MSR_IA32_MCx_CTL2(bank), val);
-	}
+	rdmsrl(MSR_IA32_MCx_CTL2(bank), val);
+	val &= ~MCI_CTL2_CMCI_THRESHOLD_MASK;
+	wrmsrl(MSR_IA32_MCx_CTL2(bank), val | thresh);
 	raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
 }
 
-unsigned long cmci_intel_adjust_timer(unsigned long interval)
+void mce_intel_handle_storm(int bank, bool on)
 {
-	if ((this_cpu_read(cmci_backoff_cnt) > 0) &&
-	    (__this_cpu_read(cmci_storm_state) == CMCI_STORM_ACTIVE)) {
-		mce_notify_irq();
-		return CMCI_STORM_INTERVAL;
-	}
-
-	switch (__this_cpu_read(cmci_storm_state)) {
-	case CMCI_STORM_ACTIVE:
-
-		/*
-		 * We switch back to interrupt mode once the poll timer has
-		 * silenced itself. That means no events recorded and the timer
-		 * interval is back to our poll interval.
-		 */
-		__this_cpu_write(cmci_storm_state, CMCI_STORM_SUBSIDED);
-		if (!atomic_sub_return(1, &cmci_storm_on_cpus))
-			pr_notice("CMCI storm subsided: switching to interrupt mode\n");
-
-		fallthrough;
-
-	case CMCI_STORM_SUBSIDED:
-		/*
-		 * We wait for all CPUs to go back to SUBSIDED state. When that
-		 * happens we switch back to interrupt mode.
-		 */
-		if (!atomic_read(&cmci_storm_on_cpus)) {
-			__this_cpu_write(cmci_storm_state, CMCI_STORM_NONE);
-			cmci_toggle_interrupt_mode(true);
-			cmci_recheck();
-		}
-		return CMCI_POLL_INTERVAL;
-	default:
-
-		/* We have shiny weather. Let the poll do whatever it thinks. */
-		return interval;
-	}
-}
-
-static bool cmci_storm_detect(void)
-{
-	unsigned int cnt = __this_cpu_read(cmci_storm_cnt);
-	unsigned long ts = __this_cpu_read(cmci_time_stamp);
-	unsigned long now = jiffies;
-	int r;
-
-	if (__this_cpu_read(cmci_storm_state) != CMCI_STORM_NONE)
-		return true;
-
-	if (time_before_eq(now, ts + CMCI_STORM_INTERVAL)) {
-		cnt++;
-	} else {
-		cnt = 1;
-		__this_cpu_write(cmci_time_stamp, now);
-	}
-	__this_cpu_write(cmci_storm_cnt, cnt);
-
-	if (cnt <= CMCI_STORM_THRESHOLD)
-		return false;
-
-	cmci_toggle_interrupt_mode(false);
-	__this_cpu_write(cmci_storm_state, CMCI_STORM_ACTIVE);
-	r = atomic_add_return(1, &cmci_storm_on_cpus);
-	mce_timer_kick(CMCI_STORM_INTERVAL);
-	this_cpu_write(cmci_backoff_cnt, INITIAL_CHECK_INTERVAL);
-
-	if (r == 1)
-		pr_notice("CMCI storm detected: switching to poll mode\n");
-	return true;
+	if (on)
+		cmci_set_threshold(bank, CMCI_STORM_THRESHOLD);
+	else
+		cmci_set_threshold(bank, cmci_threshold[bank]);
 }
 
 /*
···
  */
 static void intel_threshold_interrupt(void)
 {
-	if (cmci_storm_detect())
-		return;
-
 	machine_check_poll(MCP_TIMESTAMP, this_cpu_ptr(&mce_banks_owned));
+}
+
+/*
+ * Check all the reasons why current CPU cannot claim
+ * ownership of a bank.
+ * 1: CPU already owns this bank
+ * 2: BIOS owns this bank
+ * 3: Some other CPU owns this bank
+ */
+static bool cmci_skip_bank(int bank, u64 *val)
+{
+	unsigned long *owned = (void *)this_cpu_ptr(&mce_banks_owned);
+
+	if (test_bit(bank, owned))
+		return true;
+
+	/* Skip banks in firmware first mode */
+	if (test_bit(bank, mce_banks_ce_disabled))
+		return true;
+
+	rdmsrl(MSR_IA32_MCx_CTL2(bank), *val);
+
+	/* Already owned by someone else? */
+	if (*val & MCI_CTL2_CMCI_EN) {
+		clear_bit(bank, owned);
+		__clear_bit(bank, this_cpu_ptr(mce_poll_banks));
+		return true;
+	}
+
+	return false;
+}
+
+/*
+ * Decide which CMCI interrupt threshold to use:
+ * 1: If this bank is in storm mode from whichever CPU was
+ *    the previous owner, stay in storm mode.
+ * 2: If ignoring any threshold set by BIOS, set Linux default
+ * 3: Try to honor BIOS threshold (unless buggy BIOS set it at zero).
+ */
+static u64 cmci_pick_threshold(u64 val, int *bios_zero_thresh)
+{
+	if ((val & MCI_CTL2_CMCI_THRESHOLD_MASK) == CMCI_STORM_THRESHOLD)
+		return val;
+
+	if (!mca_cfg.bios_cmci_threshold) {
+		val &= ~MCI_CTL2_CMCI_THRESHOLD_MASK;
+		val |= CMCI_THRESHOLD;
+	} else if (!(val & MCI_CTL2_CMCI_THRESHOLD_MASK)) {
+		/*
+		 * If bios_cmci_threshold boot option was specified
+		 * but the threshold is zero, we'll try to initialize
+		 * it to 1.
+		 */
+		*bios_zero_thresh = 1;
+		val |= CMCI_THRESHOLD;
+	}
+
+	return val;
+}
+
+/*
+ * Try to claim ownership of a bank.
+ */
+static void cmci_claim_bank(int bank, u64 val, int bios_zero_thresh, int *bios_wrong_thresh)
+{
+	struct mca_storm_desc *storm = this_cpu_ptr(&storm_desc);
+
+	val |= MCI_CTL2_CMCI_EN;
+	wrmsrl(MSR_IA32_MCx_CTL2(bank), val);
+	rdmsrl(MSR_IA32_MCx_CTL2(bank), val);
+
+	/* If the enable bit did not stick, this bank should be polled. */
+	if (!(val & MCI_CTL2_CMCI_EN)) {
+		WARN_ON(!test_bit(bank, this_cpu_ptr(mce_poll_banks)));
+		storm->banks[bank].poll_only = true;
+		return;
+	}
+
+	/* This CPU successfully set the enable bit. */
+	set_bit(bank, (void *)this_cpu_ptr(&mce_banks_owned));
+
+	if ((val & MCI_CTL2_CMCI_THRESHOLD_MASK) == CMCI_STORM_THRESHOLD) {
+		pr_notice("CPU%d BANK%d CMCI inherited storm\n", smp_processor_id(), bank);
+		mce_inherit_storm(bank);
+		cmci_storm_begin(bank);
+	} else {
+		__clear_bit(bank, this_cpu_ptr(mce_poll_banks));
+	}
+
+	/*
+	 * We are able to set thresholds for some banks that
+	 * had a threshold of 0. This means the BIOS has not
+	 * set the thresholds properly or does not work with
+	 * this boot option. Note down now and report later.
+	 */
+	if (mca_cfg.bios_cmci_threshold && bios_zero_thresh &&
+	    (val & MCI_CTL2_CMCI_THRESHOLD_MASK))
+		*bios_wrong_thresh = 1;
+
+	/* Save default threshold for each bank */
+	if (cmci_threshold[bank] == 0)
+		cmci_threshold[bank] = val & MCI_CTL2_CMCI_THRESHOLD_MASK;
 }
 
 /*
  * Enable CMCI (Corrected Machine Check Interrupt) for available MCE banks
  * on this CPU. Use the algorithm recommended in the SDM to discover shared
- * banks.
+ * banks. Called during initial bootstrap, and also for hotplug CPU operations
+ * to rediscover/reassign machine check banks.
  */
 static void cmci_discover(int banks)
 {
-	unsigned long *owned = (void *)this_cpu_ptr(&mce_banks_owned);
+	int bios_wrong_thresh = 0;
 	unsigned long flags;
 	int i;
-	int bios_wrong_thresh = 0;
 
 	raw_spin_lock_irqsave(&cmci_discover_lock, flags);
 	for (i = 0; i < banks; i++) {
 		u64 val;
 		int bios_zero_thresh = 0;
 
-		if (test_bit(i, owned))
+		if (cmci_skip_bank(i, &val))
 			continue;
 
-		/* Skip banks in firmware first mode */
-		if (test_bit(i, mce_banks_ce_disabled))
-			continue;
-
-		rdmsrl(MSR_IA32_MCx_CTL2(i), val);
-
-		/* Already owned by someone else? */
-		if (val & MCI_CTL2_CMCI_EN) {
-			clear_bit(i, owned);
-			__clear_bit(i, this_cpu_ptr(mce_poll_banks));
-			continue;
-		}
-
-		if (!mca_cfg.bios_cmci_threshold) {
-			val &= ~MCI_CTL2_CMCI_THRESHOLD_MASK;
-			val |= CMCI_THRESHOLD;
-		} else if (!(val & MCI_CTL2_CMCI_THRESHOLD_MASK)) {
-			/*
-			 * If bios_cmci_threshold boot option was specified
-			 * but the threshold is zero, we'll try to initialize
-			 * it to 1.
-			 */
-			bios_zero_thresh = 1;
-			val |= CMCI_THRESHOLD;
-		}
-
-		val |= MCI_CTL2_CMCI_EN;
-		wrmsrl(MSR_IA32_MCx_CTL2(i), val);
-		rdmsrl(MSR_IA32_MCx_CTL2(i), val);
-
-		/* Did the enable bit stick? -- the bank supports CMCI */
-		if (val & MCI_CTL2_CMCI_EN) {
-			set_bit(i, owned);
-			__clear_bit(i, this_cpu_ptr(mce_poll_banks));
-			/*
-			 * We are able to set thresholds for some banks that
-			 * had a threshold of 0. This means the BIOS has not
-			 * set the thresholds properly or does not work with
-			 * this boot option. Note down now and report later.
-			 */
-			if (mca_cfg.bios_cmci_threshold && bios_zero_thresh &&
-					(val & MCI_CTL2_CMCI_THRESHOLD_MASK))
-				bios_wrong_thresh = 1;
-		} else {
-			WARN_ON(!test_bit(i, this_cpu_ptr(mce_poll_banks)));
-		}
+		val = cmci_pick_threshold(val, &bios_zero_thresh);
+		cmci_claim_bank(i, val, bios_zero_thresh, &bios_wrong_thresh);
 	}
 	raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
 	if (mca_cfg.bios_cmci_threshold && bios_wrong_thresh) {
···
 	val &= ~MCI_CTL2_CMCI_EN;
 	wrmsrl(MSR_IA32_MCx_CTL2(bank), val);
 	__clear_bit(bank, this_cpu_ptr(mce_banks_owned));
+
+	if ((val & MCI_CTL2_CMCI_THRESHOLD_MASK) == CMCI_STORM_THRESHOLD)
+		cmci_storm_end(bank);
 }
 
 /*

arch/x86/kernel/cpu/mce/internal.h

···
 extern mce_banks_t mce_banks_ce_disabled;
 
 #ifdef CONFIG_X86_MCE_INTEL
-unsigned long cmci_intel_adjust_timer(unsigned long interval);
-bool mce_intel_cmci_poll(void);
-void mce_intel_hcpu_update(unsigned long cpu);
+void mce_intel_handle_storm(int bank, bool on);
 void cmci_disable_bank(int bank);
 void intel_init_cmci(void);
 void intel_init_lmce(void);
···
 bool intel_filter_mce(struct mce *m);
 bool intel_mce_usable_address(struct mce *m);
 #else
-# define cmci_intel_adjust_timer mce_adjust_timer_default
-static inline bool mce_intel_cmci_poll(void) { return false; }
-static inline void mce_intel_hcpu_update(unsigned long cpu) { }
+static inline void mce_intel_handle_storm(int bank, bool on) { }
 static inline void cmci_disable_bank(int bank) { }
 static inline void intel_init_cmci(void) { }
 static inline void intel_init_lmce(void) { }
···
 static inline bool intel_mce_usable_address(struct mce *m) { return false; }
 #endif
 
-void mce_timer_kick(unsigned long interval);
+void mce_timer_kick(bool storm);
+
+#ifdef CONFIG_X86_MCE_THRESHOLD
+void cmci_storm_begin(unsigned int bank);
+void cmci_storm_end(unsigned int bank);
+void mce_track_storm(struct mce *mce);
+void mce_inherit_storm(unsigned int bank);
+bool mce_get_storm_mode(void);
+void mce_set_storm_mode(bool storm);
+#else
+static inline void cmci_storm_begin(unsigned int bank) {}
+static inline void cmci_storm_end(unsigned int bank) {}
+static inline void mce_track_storm(struct mce *mce) {}
+static inline void mce_inherit_storm(unsigned int bank) {}
+static inline bool mce_get_storm_mode(void) { return false; }
+static inline void mce_set_storm_mode(bool storm) {}
+#endif
+
+/*
+ * history:		Bitmask tracking errors occurrence. Each set bit
+ *			represents an error seen.
+ *
+ * timestamp:		Last time (in jiffies) that the bank was polled.
+ * in_storm_mode:	Is this bank in storm mode?
+ * poll_only:		Bank does not support CMCI, skip storm tracking.
+ */
+struct storm_bank {
+	u64 history;
+	u64 timestamp;
+	bool in_storm_mode;
+	bool poll_only;
+};
+
+#define NUM_HISTORY_BITS (sizeof(u64) * BITS_PER_BYTE)
+
+/* How many errors within the history buffer mark the start of a storm. */
+#define STORM_BEGIN_THRESHOLD	5
+
+/*
+ * How many polls of machine check bank without an error before declaring
+ * the storm is over. Since it is tracked by the bitmasks in the history
+ * field of struct storm_bank the mask is 30 bits [0 ... 29].
+ */
+#define STORM_END_POLL_THRESHOLD	29
+
+/*
+ * banks:		per-cpu, per-bank details
+ * stormy_bank_count:	count of MC banks in storm state
+ * poll_mode:		CPU is in poll mode
+ */
+struct mca_storm_desc {
+	struct storm_bank	banks[MAX_NR_BANKS];
+	u8			stormy_bank_count;
+	bool			poll_mode;
+};
+
+DECLARE_PER_CPU(struct mca_storm_desc, storm_desc);
 
 #ifdef CONFIG_ACPI_APEI
 int apei_write_mce(struct mce *m);

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

···
 	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);
+	}
+}

drivers/edac/mce_amd.c

···
 	"Status Register File",
 };
 
-/* Scalable MCA error strings */
-static const char * const smca_ls_mce_desc[] = {
-	"Load queue parity error",
-	"Store queue parity error",
-	"Miss address buffer payload parity error",
-	"Level 1 TLB parity error",
-	"DC Tag error type 5",
-	"DC Tag error type 6",
-	"DC Tag error type 1",
-	"Internal error type 1",
-	"Internal error type 2",
-	"System Read Data Error Thread 0",
-	"System Read Data Error Thread 1",
-	"DC Tag error type 2",
-	"DC Data error type 1 and poison consumption",
-	"DC Data error type 2",
-	"DC Data error type 3",
-	"DC Tag error type 4",
-	"Level 2 TLB parity error",
-	"PDC parity error",
-	"DC Tag error type 3",
-	"DC Tag error type 5",
-	"L2 Fill Data error",
-};
-
-static const char * const smca_ls2_mce_desc[] = {
-	"An ECC error was detected on a data cache read by a probe or victimization",
-	"An ECC error or L2 poison was detected on a data cache read by a load",
-	"An ECC error was detected on a data cache read-modify-write by a store",
-	"An ECC error or poison bit mismatch was detected on a tag read by a probe or victimization",
-	"An ECC error or poison bit mismatch was detected on a tag read by a load",
-	"An ECC error or poison bit mismatch was detected on a tag read by a store",
-	"An ECC error was detected on an EMEM read by a load",
-	"An ECC error was detected on an EMEM read-modify-write by a store",
-	"A parity error was detected in an L1 TLB entry by any access",
-	"A parity error was detected in an L2 TLB entry by any access",
-	"A parity error was detected in a PWC entry by any access",
-	"A parity error was detected in an STQ entry by any access",
-	"A parity error was detected in an LDQ entry by any access",
-	"A parity error was detected in a MAB entry by any access",
-	"A parity error was detected in an SCB entry state field by any access",
-	"A parity error was detected in an SCB entry address field by any access",
-	"A parity error was detected in an SCB entry data field by any access",
-	"A parity error was detected in a WCB entry by any access",
-	"A poisoned line was detected in an SCB entry by any access",
-	"A SystemReadDataError error was reported on read data returned from L2 for a load",
-	"A SystemReadDataError error was reported on read data returned from L2 for an SCB store",
-	"A SystemReadDataError error was reported on read data returned from L2 for a WCB store",
-	"A hardware assertion error was reported",
-	"A parity error was detected in an STLF, SCB EMEM entry or SRB store data by any access",
-};
-
-static const char * const smca_if_mce_desc[] = {
-	"Op Cache Microtag Probe Port Parity Error",
-	"IC Microtag or Full Tag Multi-hit Error",
-	"IC Full Tag Parity Error",
-	"IC Data Array Parity Error",
-	"Decoupling Queue PhysAddr Parity Error",
-	"L0 ITLB Parity Error",
-	"L1 ITLB Parity Error",
-	"L2 ITLB Parity Error",
-	"BPQ Thread 0 Snoop Parity Error",
-	"BPQ Thread 1 Snoop Parity Error",
-	"L1 BTB Multi-Match Error",
-	"L2 BTB Multi-Match Error",
-	"L2 Cache Response Poison Error",
-	"System Read Data Error",
-	"Hardware Assertion Error",
-	"L1-TLB Multi-Hit",
-	"L2-TLB Multi-Hit",
-	"BSR Parity Error",
-	"CT MCE",
-};
-
-static const char * const smca_l2_mce_desc[] = {
-	"L2M Tag Multiple-Way-Hit error",
-	"L2M Tag or State Array ECC Error",
-	"L2M Data Array ECC Error",
-	"Hardware Assert Error",
-};
-
-static const char * const smca_de_mce_desc[] = {
-	"Micro-op cache tag parity error",
-	"Micro-op cache data parity error",
-	"Instruction buffer parity error",
-	"Micro-op queue parity error",
-	"Instruction dispatch queue parity error",
-	"Fetch address FIFO parity error",
-	"Patch RAM data parity error",
-	"Patch RAM sequencer parity error",
-	"Micro-op buffer parity error",
-	"Hardware Assertion MCA Error",
-};
-
-static const char * const smca_ex_mce_desc[] = {
-	"Watchdog Timeout error",
-	"Physical register file parity error",
-	"Flag register file parity error",
-	"Immediate displacement register file parity error",
-	"Address generator payload parity error",
-	"EX payload parity error",
-	"Checkpoint queue parity error",
-	"Retire dispatch queue parity error",
-	"Retire status queue parity error",
-	"Scheduling queue parity error",
-	"Branch buffer queue parity error",
-	"Hardware Assertion error",
-	"Spec Map parity error",
-	"Retire Map parity error",
-};
-
-static const char * const smca_fp_mce_desc[] = {
-	"Physical register file (PRF) parity error",
-	"Freelist (FL) parity error",
-	"Schedule queue parity error",
-	"NSQ parity error",
-	"Retire queue (RQ) parity error",
-	"Status register file (SRF) parity error",
-	"Hardware assertion",
-};
-
-static const char * const smca_l3_mce_desc[] = {
-	"Shadow Tag Macro ECC Error",
-	"Shadow Tag Macro Multi-way-hit Error",
-	"L3M Tag ECC Error",
-	"L3M Tag Multi-way-hit Error",
-	"L3M Data ECC Error",
-	"SDP Parity Error or SystemReadDataError from XI",
-	"L3 Victim Queue Parity Error",
-	"L3 Hardware Assertion",
-};
-
-static const char * const smca_cs_mce_desc[] = {
-	"Illegal Request",
-	"Address Violation",
-	"Security Violation",
-	"Illegal Response",
-	"Unexpected Response",
-	"Request or Probe Parity Error",
-	"Read Response Parity Error",
-	"Atomic Request Parity Error",
-	"Probe Filter ECC Error",
-};
-
-static const char * const smca_cs2_mce_desc[] = {
-	"Illegal Request",
-	"Address Violation",
-	"Security Violation",
-	"Illegal Response",
-	"Unexpected Response",
-	"Request or Probe Parity Error",
-	"Read Response Parity Error",
-	"Atomic Request Parity Error",
-	"SDP read response had no match in the CS queue",
-	"Probe Filter Protocol Error",
-	"Probe Filter ECC Error",
-	"SDP read response had an unexpected RETRY error",
-	"Counter overflow error",
-	"Counter underflow error",
-};
-
-static const char * const smca_pie_mce_desc[] = {
-	"Hardware Assert",
-	"Register security violation",
-	"Link Error",
-	"Poison data consumption",
-	"A deferred error was detected in the DF"
-};
-
-static const char * const smca_umc_mce_desc[] = {
-	"DRAM ECC error",
-	"Data poison error",
-	"SDP parity error",
-	"Advanced peripheral bus error",
-	"Address/Command parity error",
-	"Write data CRC error",
-	"DCQ SRAM ECC error",
-	"AES SRAM ECC error",
-};
-
-static const char * const smca_umc2_mce_desc[] = {
-	"DRAM ECC error",
-	"Data poison error",
-	"SDP parity error",
-	"Reserved",
-	"Address/Command parity error",
-	"Write data parity error",
-	"DCQ SRAM ECC error",
-	"Reserved",
-	"Read data parity error",
-	"Rdb SRAM ECC error",
-	"RdRsp SRAM ECC error",
-	"LM32 MP errors",
-};
-
-static const char * const smca_pb_mce_desc[] = {
-	"An ECC error in the Parameter Block RAM array",
-};
-
-static const char * const smca_psp_mce_desc[] = {
-	"An ECC or parity error in a PSP RAM instance",
-};
-
-static const char * const smca_psp2_mce_desc[] = {
-	"High SRAM ECC or parity error",
-	"Low SRAM ECC or parity error",
-	"Instruction Cache Bank 0 ECC or parity error",
-	"Instruction Cache Bank 1 ECC or parity error",
-	"Instruction Tag Ram 0 parity error",
-	"Instruction Tag Ram 1 parity error",
-	"Data Cache Bank 0 ECC or parity error",
-	"Data Cache Bank 1 ECC or parity error",
-	"Data Cache Bank 2 ECC or parity error",
-	"Data Cache Bank 3 ECC or parity error",
-	"Data Tag Bank 0 parity error",
-	"Data Tag Bank 1 parity error",
-	"Data Tag Bank 2 parity error",
-	"Data Tag Bank 3 parity error",
-	"Dirty Data Ram parity error",
-	"TLB Bank 0 parity error",
-	"TLB Bank 1 parity error",
-	"System Hub Read Buffer ECC or parity error",
-};
-
-static const char * const smca_smu_mce_desc[] = {
-	"An ECC or parity error in an SMU RAM instance",
-};
-
-static const char * const smca_smu2_mce_desc[] = {
-	"High SRAM ECC or parity error",
-	"Low SRAM ECC or parity error",
-	"Data Cache Bank A ECC or parity error",
-	"Data Cache Bank B ECC or parity error",
-	"Data Tag Cache Bank A ECC or parity error",
-	"Data Tag Cache Bank B ECC or parity error",
-	"Instruction Cache Bank A ECC or parity error",
-	"Instruction Cache Bank B ECC or parity error",
-	"Instruction Tag Cache Bank A ECC or parity error",
-	"Instruction Tag Cache Bank B ECC or parity error",
-	"System Hub Read Buffer ECC or parity error",
-	"PHY RAM ECC error",
-};
-
-static const char * const smca_mp5_mce_desc[] = {
-	"High SRAM ECC or parity error",
-	"Low SRAM ECC or parity error",
-	"Data Cache Bank A ECC or parity error",
-	"Data Cache Bank B ECC or parity error",
-	"Data Tag Cache Bank A ECC or parity error",
-	"Data Tag Cache Bank B ECC or parity error",
-	"Instruction Cache Bank A ECC or parity error",
-	"Instruction Cache Bank B ECC or parity error",
-	"Instruction Tag Cache Bank A ECC or parity error",
-	"Instruction Tag Cache Bank B ECC or parity error",
-};
-
-static const char * const smca_mpdma_mce_desc[] = {
-	"Main SRAM [31:0] bank ECC or parity error",
-	"Main SRAM [63:32] bank ECC or parity error",
-	"Main SRAM [95:64] bank ECC or parity error",
-	"Main SRAM [127:96] bank ECC or parity error",
-	"Data Cache Bank A ECC or parity error",
-	"Data Cache Bank B ECC or parity error",
-	"Data Tag Cache Bank A ECC or parity error",
-	"Data Tag Cache Bank B ECC or parity error",
-	"Instruction Cache Bank A ECC or parity error",
-	"Instruction Cache Bank B ECC or parity error",
-	"Instruction Tag Cache Bank A ECC or parity error",
-	"Instruction Tag Cache Bank B ECC or parity error",
-	"Data Cache Bank A ECC or parity error",
-	"Data Cache Bank B ECC or parity error",
-	"Data Tag Cache Bank A ECC or parity error",
-	"Data Tag Cache Bank B ECC or parity error",
-	"Instruction Cache Bank A ECC or parity error",
-	"Instruction Cache Bank B ECC or parity error",
-	"Instruction Tag Cache Bank A ECC or parity error",
-	"Instruction Tag Cache Bank B ECC or parity error",
-	"Data Cache Bank A ECC or parity error",
-	"Data Cache Bank B ECC or parity error",
-	"Data Tag Cache Bank A ECC or parity error",
-	"Data Tag Cache Bank B ECC or parity error",
-	"Instruction Cache Bank A ECC or parity error",
-	"Instruction Cache Bank B ECC or parity error",
-	"Instruction Tag Cache Bank A ECC or parity error",
-	"Instruction Tag Cache Bank B ECC or parity error",
-	"System Hub Read Buffer ECC or parity error",
-	"MPDMA TVF DVSEC Memory ECC or parity error",
-	"MPDMA TVF MMIO Mailbox0 ECC or parity error",
-	"MPDMA TVF MMIO Mailbox1 ECC or parity error",
-	"MPDMA TVF Doorbell Memory ECC or parity error",
-	"MPDMA TVF SDP Slave Memory 0 ECC or parity error",
-	"MPDMA TVF SDP Slave Memory 1 ECC or parity error",
-	"MPDMA TVF SDP Slave Memory 2 ECC or parity error",
-	"MPDMA TVF SDP Master Memory 0 ECC or parity error",
-	"MPDMA TVF SDP Master Memory 1 ECC or parity error",
-	"MPDMA TVF SDP Master Memory 2 ECC or parity error",
-	"MPDMA TVF SDP Master Memory 3 ECC or parity error",
-	"MPDMA TVF SDP Master Memory 4 ECC or parity error",
-	"MPDMA TVF SDP Master Memory 5 ECC or parity error",
-	"MPDMA TVF SDP Master Memory 6 ECC or parity error",
-	"MPDMA PTE Command FIFO ECC or parity error",
-	"MPDMA PTE Hub Data FIFO ECC or parity error",
-	"MPDMA PTE Internal Data FIFO ECC or parity error",
-	"MPDMA PTE Command Memory DMA ECC or parity error",
-	"MPDMA PTE Command Memory Internal ECC or parity error",
-	"MPDMA PTE DMA Completion FIFO ECC or parity error",
-	"MPDMA PTE Tablewalk Completion FIFO ECC or parity error",
-	"MPDMA PTE Descriptor Completion FIFO ECC or parity error",
-	"MPDMA PTE ReadOnly Completion FIFO ECC or parity error",
-	"MPDMA PTE DirectWrite Completion FIFO ECC or parity error",
-	"SDP Watchdog Timer expired",
-};
-
-static const char * const smca_nbio_mce_desc[] = {
-	"ECC or Parity error",
-	"PCIE error",
-	"SDP ErrEvent error",
-	"SDP Egress Poison Error",
-	"IOHC Internal Poison Error",
-};
-
-static const char * const smca_pcie_mce_desc[] = {
-	"CCIX PER Message logging",
-	"CCIX Read Response with Status: Non-Data Error",
-	"CCIX Write Response with Status: Non-Data Error",
-	"CCIX Read Response with Status: Data Error",
-	"CCIX Non-okay write response with data error",
-};
-
-static const char * const smca_pcie2_mce_desc[] = {
-	"SDP Parity Error logging",
-};
-
-static const char * const smca_xgmipcs_mce_desc[] = {
-	"Data Loss Error",
-	"Training Error",
-	"Flow Control Acknowledge Error",
-	"Rx Fifo Underflow Error",
-	"Rx Fifo Overflow Error",
-	"CRC Error",
-	"BER Exceeded Error",
-	"Tx Vcid Data Error",
-	"Replay Buffer Parity Error",
-	"Data Parity Error",
-	"Replay Fifo Overflow Error",
-	"Replay Fifo Underflow Error",
-	"Elastic Fifo Overflow Error",
-	"Deskew Error",
-	"Flow Control CRC Error",
-	"Data Startup Limit Error",
-	"FC Init Timeout Error",
-	"Recovery Timeout Error",
-	"Ready Serial Timeout Error",
-	"Ready Serial Attempt Error",
-	"Recovery Attempt Error",
-	"Recovery Relock Attempt Error",
-	"Replay Attempt Error",
-	"Sync Header Error",
-	"Tx Replay Timeout Error",
-	"Rx Replay Timeout Error",
-	"LinkSub Tx Timeout Error",
-	"LinkSub Rx Timeout Error",
-	"Rx CMD Packet Error",
-};
-
-static const char * const smca_xgmiphy_mce_desc[] = {
-	"RAM ECC Error",
-	"ARC instruction buffer parity error",
-	"ARC data buffer parity error",
-	"PHY APB error",
-};
-
-static const char * const smca_nbif_mce_desc[] = {
-	"Timeout error from GMI",
-	"SRAM ECC error",
-	"NTB Error Event",
-	"SDP Parity error",
-};
-
-static const char * const smca_sata_mce_desc[] = {
-	"Parity error for port 0",
-	"Parity error for port 1",
-	"Parity error for port 2",
-	"Parity error for port 3",
-	"Parity error for port 4",
-	"Parity error for port 5",
-	"Parity error for port 6",
-	"Parity error for port 7",
-};
-
-static const char * const smca_usb_mce_desc[] = {
-	"Parity error or ECC error for S0 RAM0",
-	"Parity error or ECC error for S0 RAM1",
-	"Parity error or ECC error for S0 RAM2",
-	"Parity error for PHY RAM0",
-	"Parity error for PHY RAM1",
-	"AXI Slave Response error",
-};
-
-static const char * const smca_gmipcs_mce_desc[] = {
-	"Data Loss Error",
-	"Training Error",
-	"Replay Parity Error",
-	"Rx Fifo Underflow Error",
-	"Rx Fifo Overflow Error",
-	"CRC Error",
-	"BER Exceeded Error",
-	"Tx Fifo Underflow Error",
-	"Replay Buffer Parity Error",
-	"Tx Overflow Error",
-	"Replay Fifo Overflow Error",
-	"Replay Fifo Underflow Error",
-	"Elastic Fifo Overflow Error",
-	"Deskew Error",
-	"Offline Error",
-	"Data Startup Limit Error",
-	"FC Init Timeout Error",
-	"Recovery Timeout Error",
-	"Ready Serial Timeout Error",
-	"Ready Serial Attempt Error",
-	"Recovery Attempt Error",
-	"Recovery Relock Attempt Error",
-	"Deskew Abort Error",
-	"Rx Buffer Error",
-	"Rx LFDS Fifo Overflow Error",
-	"Rx LFDS Fifo Underflow Error",
-	"LinkSub Tx Timeout Error",
-	"LinkSub Rx Timeout Error",
-	"Rx CMD Packet Error",
-	"LFDS Training Timeout Error",
-	"LFDS FC Init Timeout Error",
-	"Data Loss Error",
-};
-
-struct smca_mce_desc {
-	const char * const *descs;
-	unsigned int num_descs;
-};
-
-static struct smca_mce_desc smca_mce_descs[] = {
-	[SMCA_LS]	= { smca_ls_mce_desc,	ARRAY_SIZE(smca_ls_mce_desc)	},
-	[SMCA_LS_V2]	= { smca_ls2_mce_desc,	ARRAY_SIZE(smca_ls2_mce_desc)	},
-	[SMCA_IF]	= { smca_if_mce_desc,	ARRAY_SIZE(smca_if_mce_desc)	},
-	[SMCA_L2_CACHE]	= { smca_l2_mce_desc,	ARRAY_SIZE(smca_l2_mce_desc)	},
-	[SMCA_DE]	= { smca_de_mce_desc,	ARRAY_SIZE(smca_de_mce_desc)	},
-	[SMCA_EX]	= { smca_ex_mce_desc,	ARRAY_SIZE(smca_ex_mce_desc)	},
-	[SMCA_FP]	= { smca_fp_mce_desc,	ARRAY_SIZE(smca_fp_mce_desc)	},
-	[SMCA_L3_CACHE]	= { smca_l3_mce_desc,	ARRAY_SIZE(smca_l3_mce_desc)	},
-	[SMCA_CS]	= { smca_cs_mce_desc,	ARRAY_SIZE(smca_cs_mce_desc)	},
-	[SMCA_CS_V2]	= { smca_cs2_mce_desc,	ARRAY_SIZE(smca_cs2_mce_desc)	},
-	[SMCA_PIE]	= { smca_pie_mce_desc,	ARRAY_SIZE(smca_pie_mce_desc)	},
-	[SMCA_UMC]	= { smca_umc_mce_desc,	ARRAY_SIZE(smca_umc_mce_desc)	},
-	[SMCA_UMC_V2]	= { smca_umc2_mce_desc,	ARRAY_SIZE(smca_umc2_mce_desc)	},
-	[SMCA_PB]	= { smca_pb_mce_desc,	ARRAY_SIZE(smca_pb_mce_desc)	},
-	[SMCA_PSP]	= { smca_psp_mce_desc,	ARRAY_SIZE(smca_psp_mce_desc)	},
-	[SMCA_PSP_V2]	= { smca_psp2_mce_desc,	ARRAY_SIZE(smca_psp2_mce_desc)	},
-	[SMCA_SMU]	= { smca_smu_mce_desc,	ARRAY_SIZE(smca_smu_mce_desc)	},
-	[SMCA_SMU_V2]	= { smca_smu2_mce_desc,	ARRAY_SIZE(smca_smu2_mce_desc)	},
-	[SMCA_MP5]	= { smca_mp5_mce_desc,	ARRAY_SIZE(smca_mp5_mce_desc)	},
-	[SMCA_MPDMA]	= { smca_mpdma_mce_desc,	ARRAY_SIZE(smca_mpdma_mce_desc)	},
-	[SMCA_NBIO]	= { smca_nbio_mce_desc,	ARRAY_SIZE(smca_nbio_mce_desc)	},
-	[SMCA_PCIE]	= { smca_pcie_mce_desc,	ARRAY_SIZE(smca_pcie_mce_desc)	},
-	[SMCA_PCIE_V2]	= { smca_pcie2_mce_desc,   ARRAY_SIZE(smca_pcie2_mce_desc)	},
-	[SMCA_XGMI_PCS]	= { smca_xgmipcs_mce_desc, ARRAY_SIZE(smca_xgmipcs_mce_desc)	},
-	/* NBIF and SHUB have the same error descriptions, for now. */
-	[SMCA_NBIF]	= { smca_nbif_mce_desc, ARRAY_SIZE(smca_nbif_mce_desc)	},
-	[SMCA_SHUB]	= { smca_nbif_mce_desc, ARRAY_SIZE(smca_nbif_mce_desc)	},
-	[SMCA_SATA]	= { smca_sata_mce_desc, ARRAY_SIZE(smca_sata_mce_desc)	},
-	[SMCA_USB]	= { smca_usb_mce_desc,	ARRAY_SIZE(smca_usb_mce_desc)	},
-	[SMCA_GMI_PCS]	= { smca_gmipcs_mce_desc,  ARRAY_SIZE(smca_gmipcs_mce_desc)	},
-	/* All the PHY bank types have the same error descriptions, for now. */
-	[SMCA_XGMI_PHY]	= { smca_xgmiphy_mce_desc, ARRAY_SIZE(smca_xgmiphy_mce_desc)	},
-	[SMCA_WAFL_PHY]	= { smca_xgmiphy_mce_desc, ARRAY_SIZE(smca_xgmiphy_mce_desc)	},
-	[SMCA_GMI_PHY]	= { smca_xgmiphy_mce_desc, ARRAY_SIZE(smca_xgmiphy_mce_desc)	},
-};
-
 static bool f12h_mc0_mce(u16 ec, u8 xec)
 {
 	bool ret = false;
···
 	pr_emerg(HW_ERR "Corrupted MC6 MCE info?\n");
 }
 
+static const char * const smca_long_names[] = {
+	[SMCA_LS ... SMCA_LS_V2]	= "Load Store Unit",
+	[SMCA_IF]			= "Instruction Fetch Unit",
+	[SMCA_L2_CACHE]			= "L2 Cache",
+	[SMCA_DE]			= "Decode Unit",
+	[SMCA_RESERVED]			= "Reserved",
+	[SMCA_EX]			= "Execution Unit",
+	[SMCA_FP]			= "Floating Point Unit",
+	[SMCA_L3_CACHE]			= "L3 Cache",
+	[SMCA_CS ... SMCA_CS_V2]	= "Coherent Slave",
+	[SMCA_PIE]			= "Power, Interrupts, etc.",
+
+	/* UMC v2 is separate because both of them can exist in a single system. */
+	[SMCA_UMC]			= "Unified Memory Controller",
+	[SMCA_UMC_V2]			= "Unified Memory Controller v2",
+	[SMCA_PB]			= "Parameter Block",
+	[SMCA_PSP ... SMCA_PSP_V2]	= "Platform Security Processor",
+	[SMCA_SMU ... SMCA_SMU_V2]	= "System Management Unit",
+	[SMCA_MP5]			= "Microprocessor 5 Unit",
+	[SMCA_MPDMA]			= "MPDMA Unit",
+	[SMCA_NBIO]			= "Northbridge IO Unit",
+	[SMCA_PCIE ... SMCA_PCIE_V2]	= "PCI Express Unit",
+	[SMCA_XGMI_PCS]			= "Ext Global Memory Interconnect PCS Unit",
+	[SMCA_NBIF]			= "NBIF Unit",
+	[SMCA_SHUB]			= "System Hub Unit",
+	[SMCA_SATA]			= "SATA Unit",
+	[SMCA_USB]			= "USB Unit",
+	[SMCA_GMI_PCS]			= "Global Memory Interconnect PCS Unit",
+	[SMCA_XGMI_PHY]			= "Ext Global Memory Interconnect PHY Unit",
+	[SMCA_WAFL_PHY]			= "WAFL PHY Unit",
+	[SMCA_GMI_PHY]			= "Global Memory Interconnect PHY Unit",
+};
+
+static const char *smca_get_long_name(enum smca_bank_types t)
+{
+	if (t >= N_SMCA_BANK_TYPES)
+		return NULL;
+
+	return smca_long_names[t];
+}
+
 /* Decode errors according to Scalable MCA specification */
 static void decode_smca_error(struct mce *m)
 {
 	enum smca_bank_types bank_type = smca_get_bank_type(m->extcpu, m->bank);
-	const char *ip_name;
 	u8 xec = XEC(m->status, xec_mask);
 
 	if (bank_type >= N_SMCA_BANK_TYPES)
···
 		return;
 	}
 
-	ip_name = smca_get_long_name(bank_type);
-
-	pr_emerg(HW_ERR "%s Ext. Error Code: %d", ip_name, xec);
-
-	/* Only print the decode of valid error codes */
-	if (xec < smca_mce_descs[bank_type].num_descs)
-		pr_cont(", %s.\n", smca_mce_descs[bank_type].descs[xec]);
+	pr_emerg(HW_ERR "%s Ext. Error Code: %d", smca_get_long_name(bank_type), xec);
 
 	if ((bank_type == SMCA_UMC || bank_type == SMCA_UMC_V2) &&
 	    xec == 0 && decode_dram_ecc)