1 files changed, 875 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/pseries/ras.c b/arch/powerpc/platforms/pseries/ras.c
new file mode 100644
index 000000000..b2b245b25
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -0,0 +1,875 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2001 Dave Engebretsen IBM Corporation
+ */
+
+#include <linux/sched.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/of.h>
+#include <linux/fs.h>
+#include <linux/reboot.h>
+#include <linux/irq_work.h>
+
+#include <asm/machdep.h>
+#include <asm/rtas.h>
+#include <asm/firmware.h>
+#include <asm/mce.h>
+
+#include "pseries.h"
+
+static unsigned char ras_log_buf[RTAS_ERROR_LOG_MAX];
+static DEFINE_SPINLOCK(ras_log_buf_lock);
+
+static int ras_check_exception_token;
+
+static void mce_process_errlog_event(struct irq_work *work);
+static struct irq_work mce_errlog_process_work = {
+	.func = mce_process_errlog_event,
+};
+
+#define EPOW_SENSOR_TOKEN	9
+#define EPOW_SENSOR_INDEX	0
+
+/* EPOW events counter variable */
+static int num_epow_events;
+
+static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id);
+static irqreturn_t ras_epow_interrupt(int irq, void *dev_id);
+static irqreturn_t ras_error_interrupt(int irq, void *dev_id);
+
+/* RTAS pseries MCE errorlog section. */
+struct pseries_mc_errorlog {
+	__be32	fru_id;
+	__be32	proc_id;
+	u8	error_type;
+	/*
+	 * sub_err_type (1 byte). Bit fields depends on error_type
+	 *
+	 *   MSB0
+	 *   |
+	 *   V
+	 *   01234567
+	 *   XXXXXXXX
+	 *
+	 * For error_type == MC_ERROR_TYPE_UE
+	 *   XXXXXXXX
+	 *   X		1: Permanent or Transient UE.
+	 *    X		1: Effective address provided.
+	 *     X	1: Logical address provided.
+	 *      XX	2: Reserved.
+	 *        XXX	3: Type of UE error.
+	 *
+	 * For error_type != MC_ERROR_TYPE_UE
+	 *   XXXXXXXX
+	 *   X		1: Effective address provided.
+	 *    XXXXX	5: Reserved.
+	 *         XX	2: Type of SLB/ERAT/TLB error.
+	 */
+	u8	sub_err_type;
+	u8	reserved_1[6];
+	__be64	effective_address;
+	__be64	logical_address;
+} __packed;
+
+/* RTAS pseries MCE error types */
+#define MC_ERROR_TYPE_UE		0x00
+#define MC_ERROR_TYPE_SLB		0x01
+#define MC_ERROR_TYPE_ERAT		0x02
+#define MC_ERROR_TYPE_UNKNOWN		0x03
+#define MC_ERROR_TYPE_TLB		0x04
+#define MC_ERROR_TYPE_D_CACHE		0x05
+#define MC_ERROR_TYPE_I_CACHE		0x07
+
+/* RTAS pseries MCE error sub types */
+#define MC_ERROR_UE_INDETERMINATE		0
+#define MC_ERROR_UE_IFETCH			1
+#define MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH	2
+#define MC_ERROR_UE_LOAD_STORE			3
+#define MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE	4
+
+#define UE_EFFECTIVE_ADDR_PROVIDED		0x40
+#define UE_LOGICAL_ADDR_PROVIDED		0x20
+
+#define MC_ERROR_SLB_PARITY		0
+#define MC_ERROR_SLB_MULTIHIT		1
+#define MC_ERROR_SLB_INDETERMINATE	2
+
+#define MC_ERROR_ERAT_PARITY		1
+#define MC_ERROR_ERAT_MULTIHIT		2
+#define MC_ERROR_ERAT_INDETERMINATE	3
+
+#define MC_ERROR_TLB_PARITY		1
+#define MC_ERROR_TLB_MULTIHIT		2
+#define MC_ERROR_TLB_INDETERMINATE	3
+
+static inline u8 rtas_mc_error_sub_type(const struct pseries_mc_errorlog *mlog)
+{
+	switch (mlog->error_type) {
+	case	MC_ERROR_TYPE_UE:
+		return (mlog->sub_err_type & 0x07);
+	case	MC_ERROR_TYPE_SLB:
+	case	MC_ERROR_TYPE_ERAT:
+	case	MC_ERROR_TYPE_TLB:
+		return (mlog->sub_err_type & 0x03);
+	default:
+		return 0;
+	}
+}
+
+/*
+ * Enable the hotplug interrupt late because processing them may touch other
+ * devices or systems (e.g. hugepages) that have not been initialized at the
+ * subsys stage.
+ */
+int __init init_ras_hotplug_IRQ(void)
+{
+	struct device_node *np;
+
+	/* Hotplug Events */
+	np = of_find_node_by_path("/event-sources/hot-plug-events");
+	if (np != NULL) {
+		if (dlpar_workqueue_init() == 0)
+			request_event_sources_irqs(np, ras_hotplug_interrupt,
+						   "RAS_HOTPLUG");
+		of_node_put(np);
+	}
+
+	return 0;
+}
+machine_late_initcall(pseries, init_ras_hotplug_IRQ);
+
+/*
+ * Initialize handlers for the set of interrupts caused by hardware errors
+ * and power system events.
+ */
+static int __init init_ras_IRQ(void)
+{
+	struct device_node *np;
+
+	ras_check_exception_token = rtas_token("check-exception");
+
+	/* Internal Errors */
+	np = of_find_node_by_path("/event-sources/internal-errors");
+	if (np != NULL) {
+		request_event_sources_irqs(np, ras_error_interrupt,
+					   "RAS_ERROR");
+		of_node_put(np);
+	}
+
+	/* EPOW Events */
+	np = of_find_node_by_path("/event-sources/epow-events");
+	if (np != NULL) {
+		request_event_sources_irqs(np, ras_epow_interrupt, "RAS_EPOW");
+		of_node_put(np);
+	}
+
+	return 0;
+}
+machine_subsys_initcall(pseries, init_ras_IRQ);
+
+#define EPOW_SHUTDOWN_NORMAL				1
+#define EPOW_SHUTDOWN_ON_UPS				2
+#define EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS	3
+#define EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH	4
+
+static void handle_system_shutdown(char event_modifier)
+{
+	switch (event_modifier) {
+	case EPOW_SHUTDOWN_NORMAL:
+		pr_emerg("Power off requested\n");
+		orderly_poweroff(true);
+		break;
+
+	case EPOW_SHUTDOWN_ON_UPS:
+		pr_emerg("Loss of system power detected. System is running on"
+			 " UPS/battery. Check RTAS error log for details\n");
+		break;
+
+	case EPOW_SHUTDOWN_LOSS_OF_CRITICAL_FUNCTIONS:
+		pr_emerg("Loss of system critical functions detected. Check"
+			 " RTAS error log for details\n");
+		orderly_poweroff(true);
+		break;
+
+	case EPOW_SHUTDOWN_AMBIENT_TEMPERATURE_TOO_HIGH:
+		pr_emerg("High ambient temperature detected. Check RTAS"
+			 " error log for details\n");
+		orderly_poweroff(true);
+		break;
+
+	default:
+		pr_err("Unknown power/cooling shutdown event (modifier = %d)\n",
+			event_modifier);
+	}
+}
+
+struct epow_errorlog {
+	unsigned char sensor_value;
+	unsigned char event_modifier;
+	unsigned char extended_modifier;
+	unsigned char reserved;
+	unsigned char platform_reason;
+};
+
+#define EPOW_RESET			0
+#define EPOW_WARN_COOLING		1
+#define EPOW_WARN_POWER			2
+#define EPOW_SYSTEM_SHUTDOWN		3
+#define EPOW_SYSTEM_HALT		4
+#define EPOW_MAIN_ENCLOSURE		5
+#define EPOW_POWER_OFF			7
+
+static void rtas_parse_epow_errlog(struct rtas_error_log *log)
+{
+	struct pseries_errorlog *pseries_log;
+	struct epow_errorlog *epow_log;
+	char action_code;
+	char modifier;
+
+	pseries_log = get_pseries_errorlog(log, PSERIES_ELOG_SECT_ID_EPOW);
+	if (pseries_log == NULL)
+		return;
+
+	epow_log = (struct epow_errorlog *)pseries_log->data;
+	action_code = epow_log->sensor_value & 0xF;	/* bottom 4 bits */
+	modifier = epow_log->event_modifier & 0xF;	/* bottom 4 bits */
+
+	switch (action_code) {
+	case EPOW_RESET:
+		if (num_epow_events) {
+			pr_info("Non critical power/cooling issue cleared\n");
+			num_epow_events--;
+		}
+		break;
+
+	case EPOW_WARN_COOLING:
+		pr_info("Non-critical cooling issue detected. Check RTAS error"
+			" log for details\n");
+		break;
+
+	case EPOW_WARN_POWER:
+		pr_info("Non-critical power issue detected. Check RTAS error"
+			" log for details\n");
+		break;
+
+	case EPOW_SYSTEM_SHUTDOWN:
+		handle_system_shutdown(modifier);
+		break;
+
+	case EPOW_SYSTEM_HALT:
+		pr_emerg("Critical power/cooling issue detected. Check RTAS"
+			 " error log for details. Powering off.\n");
+		orderly_poweroff(true);
+		break;
+
+	case EPOW_MAIN_ENCLOSURE:
+	case EPOW_POWER_OFF:
+		pr_emerg("System about to lose power. Check RTAS error log "
+			 " for details. Powering off immediately.\n");
+		emergency_sync();
+		kernel_power_off();
+		break;
+
+	default:
+		pr_err("Unknown power/cooling event (action code  = %d)\n",
+			action_code);
+	}
+
+	/* Increment epow events counter variable */
+	if (action_code != EPOW_RESET)
+		num_epow_events++;
+}
+
+static irqreturn_t ras_hotplug_interrupt(int irq, void *dev_id)
+{
+	struct pseries_errorlog *pseries_log;
+	struct pseries_hp_errorlog *hp_elog;
+
+	spin_lock(&ras_log_buf_lock);
+
+	rtas_call(ras_check_exception_token, 6, 1, NULL,
+		  RTAS_VECTOR_EXTERNAL_INTERRUPT, virq_to_hw(irq),
+		  RTAS_HOTPLUG_EVENTS, 0, __pa(&ras_log_buf),
+		  rtas_get_error_log_max());
+
+	pseries_log = get_pseries_errorlog((struct rtas_error_log *)ras_log_buf,
+					   PSERIES_ELOG_SECT_ID_HOTPLUG);
+	hp_elog = (struct pseries_hp_errorlog *)pseries_log->data;
+
+	/*
+	 * Since PCI hotplug is not currently supported on pseries, put PCI
+	 * hotplug events on the ras_log_buf to be handled by rtas_errd.
+	 */
+	if (hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_MEM ||
+	    hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_CPU ||
+	    hp_elog->resource == PSERIES_HP_ELOG_RESOURCE_PMEM)
+		queue_hotplug_event(hp_elog);
+	else
+		log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
+
+	spin_unlock(&ras_log_buf_lock);
+	return IRQ_HANDLED;
+}
+
+/* Handle environmental and power warning (EPOW) interrupts. */
+static irqreturn_t ras_epow_interrupt(int irq, void *dev_id)
+{
+	int status;
+	int state;
+	int critical;
+
+	status = rtas_get_sensor_fast(EPOW_SENSOR_TOKEN, EPOW_SENSOR_INDEX,
+				      &state);
+
+	if (state > 3)
+		critical = 1;		/* Time Critical */
+	else
+		critical = 0;
+
+	spin_lock(&ras_log_buf_lock);
+
+	status = rtas_call(ras_check_exception_token, 6, 1, NULL,
+			   RTAS_VECTOR_EXTERNAL_INTERRUPT,
+			   virq_to_hw(irq),
+			   RTAS_EPOW_WARNING,
+			   critical, __pa(&ras_log_buf),
+				rtas_get_error_log_max());
+
+	log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, 0);
+
+	rtas_parse_epow_errlog((struct rtas_error_log *)ras_log_buf);
+
+	spin_unlock(&ras_log_buf_lock);
+	return IRQ_HANDLED;
+}
+
+/*
+ * Handle hardware error interrupts.
+ *
+ * RTAS check-exception is called to collect data on the exception.  If
+ * the error is deemed recoverable, we log a warning and return.
+ * For nonrecoverable errors, an error is logged and we stop all processing
+ * as quickly as possible in order to prevent propagation of the failure.
+ */
+static irqreturn_t ras_error_interrupt(int irq, void *dev_id)
+{
+	struct rtas_error_log *rtas_elog;
+	int status;
+	int fatal;
+
+	spin_lock(&ras_log_buf_lock);
+
+	status = rtas_call(ras_check_exception_token, 6, 1, NULL,
+			   RTAS_VECTOR_EXTERNAL_INTERRUPT,
+			   virq_to_hw(irq),
+			   RTAS_INTERNAL_ERROR, 1 /* Time Critical */,
+			   __pa(&ras_log_buf),
+				rtas_get_error_log_max());
+
+	rtas_elog = (struct rtas_error_log *)ras_log_buf;
+
+	if (status == 0 &&
+	    rtas_error_severity(rtas_elog) >= RTAS_SEVERITY_ERROR_SYNC)
+		fatal = 1;
+	else
+		fatal = 0;
+
+	/* format and print the extended information */
+	log_error(ras_log_buf, ERR_TYPE_RTAS_LOG, fatal);
+
+	if (fatal) {
+		pr_emerg("Fatal hardware error detected. Check RTAS error"
+			 " log for details. Powering off immediately\n");
+		emergency_sync();
+		kernel_power_off();
+	} else {
+		pr_err("Recoverable hardware error detected\n");
+	}
+
+	spin_unlock(&ras_log_buf_lock);
+	return IRQ_HANDLED;
+}
+
+/*
+ * Some versions of FWNMI place the buffer inside the 4kB page starting at
+ * 0x7000. Other versions place it inside the rtas buffer. We check both.
+ * Minimum size of the buffer is 16 bytes.
+ */
+#define VALID_FWNMI_BUFFER(A) \
+	((((A) >= 0x7000) && ((A) <= 0x8000 - 16)) || \
+	(((A) >= rtas.base) && ((A) <= (rtas.base + rtas.size - 16))))
+
+static inline struct rtas_error_log *fwnmi_get_errlog(void)
+{
+	return (struct rtas_error_log *)local_paca->mce_data_buf;
+}
+
+static __be64 *fwnmi_get_savep(struct pt_regs *regs)
+{
+	unsigned long savep_ra;
+
+	/* Mask top two bits */
+	savep_ra = regs->gpr[3] & ~(0x3UL << 62);
+	if (!VALID_FWNMI_BUFFER(savep_ra)) {
+		printk(KERN_ERR "FWNMI: corrupt r3 0x%016lx\n", regs->gpr[3]);
+		return NULL;
+	}
+
+	return __va(savep_ra);
+}
+
+/*
+ * Get the error information for errors coming through the
+ * FWNMI vectors.  The pt_regs' r3 will be updated to reflect
+ * the actual r3 if possible, and a ptr to the error log entry
+ * will be returned if found.
+ *
+ * Use one buffer mce_data_buf per cpu to store RTAS error.
+ *
+ * The mce_data_buf does not have any locks or protection around it,
+ * if a second machine check comes in, or a system reset is done
+ * before we have logged the error, then we will get corruption in the
+ * error log.  This is preferable over holding off on calling
+ * ibm,nmi-interlock which would result in us checkstopping if a
+ * second machine check did come in.
+ */
+static struct rtas_error_log *fwnmi_get_errinfo(struct pt_regs *regs)
+{
+	struct rtas_error_log *h;
+	__be64 *savep;
+
+	savep = fwnmi_get_savep(regs);
+	if (!savep)
+		return NULL;
+
+	regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */
+
+	h = (struct rtas_error_log *)&savep[1];
+	/* Use the per cpu buffer from paca to store rtas error log */
+	memset(local_paca->mce_data_buf, 0, RTAS_ERROR_LOG_MAX);
+	if (!rtas_error_extended(h)) {
+		memcpy(local_paca->mce_data_buf, h, sizeof(__u64));
+	} else {
+		int len, error_log_length;
+
+		error_log_length = 8 + rtas_error_extended_log_length(h);
+		len = min_t(int, error_log_length, RTAS_ERROR_LOG_MAX);
+		memcpy(local_paca->mce_data_buf, h, len);
+	}
+
+	return (struct rtas_error_log *)local_paca->mce_data_buf;
+}
+
+/* Call this when done with the data returned by FWNMI_get_errinfo.
+ * It will release the saved data area for other CPUs in the
+ * partition to receive FWNMI errors.
+ */
+static void fwnmi_release_errinfo(void)
+{
+	struct rtas_args rtas_args;
+	int ret;
+
+	/*
+	 * On pseries, the machine check stack is limited to under 4GB, so
+	 * args can be on-stack.
+	 */
+	rtas_call_unlocked(&rtas_args, ibm_nmi_interlock_token, 0, 1, NULL);
+	ret = be32_to_cpu(rtas_args.rets[0]);
+	if (ret != 0)
+		printk(KERN_ERR "FWNMI: nmi-interlock failed: %d\n", ret);
+}
+
+int pSeries_system_reset_exception(struct pt_regs *regs)
+{
+#ifdef __LITTLE_ENDIAN__
+	/*
+	 * Some firmware byteswaps SRR registers and gives incorrect SRR1. Try
+	 * to detect the bad SRR1 pattern here. Flip the NIP back to correct
+	 * endian for reporting purposes. Unfortunately the MSR can't be fixed,
+	 * so clear it. It will be missing MSR_RI so we won't try to recover.
+	 */
+	if ((be64_to_cpu(regs->msr) &
+			(MSR_LE|MSR_RI|MSR_DR|MSR_IR|MSR_ME|MSR_PR|
+			 MSR_ILE|MSR_HV|MSR_SF)) == (MSR_DR|MSR_SF)) {
+		regs->nip = be64_to_cpu((__be64)regs->nip);
+		regs->msr = 0;
+	}
+#endif
+
+	if (fwnmi_active) {
+		__be64 *savep;
+
+		/*
+		 * Firmware (PowerVM and KVM) saves r3 to a save area like
+		 * machine check, which is not exactly what PAPR (2.9)
+		 * suggests but there is no way to detect otherwise, so this
+		 * is the interface now.
+		 *
+		 * System resets do not save any error log or require an
+		 * "ibm,nmi-interlock" rtas call to release.
+		 */
+
+		savep = fwnmi_get_savep(regs);
+		if (savep)
+			regs->gpr[3] = be64_to_cpu(savep[0]); /* restore original r3 */
+	}
+
+	if (smp_handle_nmi_ipi(regs))
+		return 1;
+
+	return 0; /* need to perform reset */
+}
+
+static int mce_handle_err_realmode(int disposition, u8 error_type)
+{
+#ifdef CONFIG_PPC_BOOK3S_64
+	if (disposition == RTAS_DISP_NOT_RECOVERED) {
+		switch (error_type) {
+		case	MC_ERROR_TYPE_SLB:
+		case	MC_ERROR_TYPE_ERAT:
+			/*
+			 * Store the old slb content in paca before flushing.
+			 * Print this when we go to virtual mode.
+			 * There are chances that we may hit MCE again if there
+			 * is a parity error on the SLB entry we trying to read
+			 * for saving. Hence limit the slb saving to single
+			 * level of recursion.
+			 */
+			if (local_paca->in_mce == 1)
+				slb_save_contents(local_paca->mce_faulty_slbs);
+			flush_and_reload_slb();
+			disposition = RTAS_DISP_FULLY_RECOVERED;
+			break;
+		default:
+			break;
+		}
+	} else if (disposition == RTAS_DISP_LIMITED_RECOVERY) {
+		/* Platform corrected itself but could be degraded */
+		pr_err("MCE: limited recovery, system may be degraded\n");
+		disposition = RTAS_DISP_FULLY_RECOVERED;
+	}
+#endif
+	return disposition;
+}
+
+static int mce_handle_err_virtmode(struct pt_regs *regs,
+				   struct rtas_error_log *errp,
+				   struct pseries_mc_errorlog *mce_log,
+				   int disposition)
+{
+	struct mce_error_info mce_err = { 0 };
+	int initiator = rtas_error_initiator(errp);
+	int severity = rtas_error_severity(errp);
+	unsigned long eaddr = 0, paddr = 0;
+	u8 error_type, err_sub_type;
+
+	if (!mce_log)
+		goto out;
+
+	error_type = mce_log->error_type;
+	err_sub_type = rtas_mc_error_sub_type(mce_log);
+
+	if (initiator == RTAS_INITIATOR_UNKNOWN)
+		mce_err.initiator = MCE_INITIATOR_UNKNOWN;
+	else if (initiator == RTAS_INITIATOR_CPU)
+		mce_err.initiator = MCE_INITIATOR_CPU;
+	else if (initiator == RTAS_INITIATOR_PCI)
+		mce_err.initiator = MCE_INITIATOR_PCI;
+	else if (initiator == RTAS_INITIATOR_ISA)
+		mce_err.initiator = MCE_INITIATOR_ISA;
+	else if (initiator == RTAS_INITIATOR_MEMORY)
+		mce_err.initiator = MCE_INITIATOR_MEMORY;
+	else if (initiator == RTAS_INITIATOR_POWERMGM)
+		mce_err.initiator = MCE_INITIATOR_POWERMGM;
+	else
+		mce_err.initiator = MCE_INITIATOR_UNKNOWN;
+
+	if (severity == RTAS_SEVERITY_NO_ERROR)
+		mce_err.severity = MCE_SEV_NO_ERROR;
+	else if (severity == RTAS_SEVERITY_EVENT)
+		mce_err.severity = MCE_SEV_WARNING;
+	else if (severity == RTAS_SEVERITY_WARNING)
+		mce_err.severity = MCE_SEV_WARNING;
+	else if (severity == RTAS_SEVERITY_ERROR_SYNC)
+		mce_err.severity = MCE_SEV_SEVERE;
+	else if (severity == RTAS_SEVERITY_ERROR)
+		mce_err.severity = MCE_SEV_SEVERE;
+	else if (severity == RTAS_SEVERITY_FATAL)
+		mce_err.severity = MCE_SEV_FATAL;
+	else
+		mce_err.severity = MCE_SEV_FATAL;
+
+	if (severity <= RTAS_SEVERITY_ERROR_SYNC)
+		mce_err.sync_error = true;
+	else
+		mce_err.sync_error = false;
+
+	mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
+	mce_err.error_class = MCE_ECLASS_UNKNOWN;
+
+	switch (error_type) {
+	case MC_ERROR_TYPE_UE:
+		mce_err.error_type = MCE_ERROR_TYPE_UE;
+		mce_common_process_ue(regs, &mce_err);
+		if (mce_err.ignore_event)
+			disposition = RTAS_DISP_FULLY_RECOVERED;
+		switch (err_sub_type) {
+		case MC_ERROR_UE_IFETCH:
+			mce_err.u.ue_error_type = MCE_UE_ERROR_IFETCH;
+			break;
+		case MC_ERROR_UE_PAGE_TABLE_WALK_IFETCH:
+			mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_IFETCH;
+			break;
+		case MC_ERROR_UE_LOAD_STORE:
+			mce_err.u.ue_error_type = MCE_UE_ERROR_LOAD_STORE;
+			break;
+		case MC_ERROR_UE_PAGE_TABLE_WALK_LOAD_STORE:
+			mce_err.u.ue_error_type = MCE_UE_ERROR_PAGE_TABLE_WALK_LOAD_STORE;
+			break;
+		case MC_ERROR_UE_INDETERMINATE:
+		default:
+			mce_err.u.ue_error_type = MCE_UE_ERROR_INDETERMINATE;
+			break;
+		}
+		if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED)
+			eaddr = be64_to_cpu(mce_log->effective_address);
+
+		if (mce_log->sub_err_type & UE_LOGICAL_ADDR_PROVIDED) {
+			paddr = be64_to_cpu(mce_log->logical_address);
+		} else if (mce_log->sub_err_type & UE_EFFECTIVE_ADDR_PROVIDED) {
+			unsigned long pfn;
+
+			pfn = addr_to_pfn(regs, eaddr);
+			if (pfn != ULONG_MAX)
+				paddr = pfn << PAGE_SHIFT;
+		}
+
+		break;
+	case MC_ERROR_TYPE_SLB:
+		mce_err.error_type = MCE_ERROR_TYPE_SLB;
+		switch (err_sub_type) {
+		case MC_ERROR_SLB_PARITY:
+			mce_err.u.slb_error_type = MCE_SLB_ERROR_PARITY;
+			break;
+		case MC_ERROR_SLB_MULTIHIT:
+			mce_err.u.slb_error_type = MCE_SLB_ERROR_MULTIHIT;
+			break;
+		case MC_ERROR_SLB_INDETERMINATE:
+		default:
+			mce_err.u.slb_error_type = MCE_SLB_ERROR_INDETERMINATE;
+			break;
+		}
+		if (mce_log->sub_err_type & 0x80)
+			eaddr = be64_to_cpu(mce_log->effective_address);
+		break;
+	case MC_ERROR_TYPE_ERAT:
+		mce_err.error_type = MCE_ERROR_TYPE_ERAT;
+		switch (err_sub_type) {
+		case MC_ERROR_ERAT_PARITY:
+			mce_err.u.erat_error_type = MCE_ERAT_ERROR_PARITY;
+			break;
+		case MC_ERROR_ERAT_MULTIHIT:
+			mce_err.u.erat_error_type = MCE_ERAT_ERROR_MULTIHIT;
+			break;
+		case MC_ERROR_ERAT_INDETERMINATE:
+		default:
+			mce_err.u.erat_error_type = MCE_ERAT_ERROR_INDETERMINATE;
+			break;
+		}
+		if (mce_log->sub_err_type & 0x80)
+			eaddr = be64_to_cpu(mce_log->effective_address);
+		break;
+	case MC_ERROR_TYPE_TLB:
+		mce_err.error_type = MCE_ERROR_TYPE_TLB;
+		switch (err_sub_type) {
+		case MC_ERROR_TLB_PARITY:
+			mce_err.u.tlb_error_type = MCE_TLB_ERROR_PARITY;
+			break;
+		case MC_ERROR_TLB_MULTIHIT:
+			mce_err.u.tlb_error_type = MCE_TLB_ERROR_MULTIHIT;
+			break;
+		case MC_ERROR_TLB_INDETERMINATE:
+		default:
+			mce_err.u.tlb_error_type = MCE_TLB_ERROR_INDETERMINATE;
+			break;
+		}
+		if (mce_log->sub_err_type & 0x80)
+			eaddr = be64_to_cpu(mce_log->effective_address);
+		break;
+	case MC_ERROR_TYPE_D_CACHE:
+		mce_err.error_type = MCE_ERROR_TYPE_DCACHE;
+		break;
+	case MC_ERROR_TYPE_I_CACHE:
+		mce_err.error_type = MCE_ERROR_TYPE_DCACHE;
+		break;
+	case MC_ERROR_TYPE_UNKNOWN:
+	default:
+		mce_err.error_type = MCE_ERROR_TYPE_UNKNOWN;
+		break;
+	}
+out:
+	save_mce_event(regs, disposition == RTAS_DISP_FULLY_RECOVERED,
+		       &mce_err, regs->nip, eaddr, paddr);
+	return disposition;
+}
+
+static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp)
+{
+	struct pseries_errorlog *pseries_log;
+	struct pseries_mc_errorlog *mce_log = NULL;
+	int disposition = rtas_error_disposition(errp);
+	u8 error_type;
+
+	if (!rtas_error_extended(errp))
+		goto out;
+
+	pseries_log = get_pseries_errorlog(errp, PSERIES_ELOG_SECT_ID_MCE);
+	if (!pseries_log)
+		goto out;
+
+	mce_log = (struct pseries_mc_errorlog *)pseries_log->data;
+	error_type = mce_log->error_type;
+
+	disposition = mce_handle_err_realmode(disposition, error_type);
+
+	/*
+	 * Enable translation as we will be accessing per-cpu variables
+	 * in save_mce_event() which may fall outside RMO region, also
+	 * leave it enabled because subsequently we will be queuing work
+	 * to workqueues where again per-cpu variables accessed, besides
+	 * fwnmi_release_errinfo() crashes when called in realmode on
+	 * pseries.
+	 * Note: All the realmode handling like flushing SLB entries for
+	 *       SLB multihit is done by now.
+	 */
+out:
+	mtmsr(mfmsr() | MSR_IR | MSR_DR);
+	disposition = mce_handle_err_virtmode(regs, errp, mce_log,
+					      disposition);
+	return disposition;
+}
+
+/*
+ * Process MCE rtas errlog event.
+ */
+static void mce_process_errlog_event(struct irq_work *work)
+{
+	struct rtas_error_log *err;
+
+	err = fwnmi_get_errlog();
+	log_error((char *)err, ERR_TYPE_RTAS_LOG, 0);
+}
+
+/*
+ * See if we can recover from a machine check exception.
+ * This is only called on power4 (or above) and only via
+ * the Firmware Non-Maskable Interrupts (fwnmi) handler
+ * which provides the error analysis for us.
+ *
+ * Return 1 if corrected (or delivered a signal).
+ * Return 0 if there is nothing we can do.
+ */
+static int recover_mce(struct pt_regs *regs, struct machine_check_event *evt)
+{
+	int recovered = 0;
+
+	if (!(regs->msr & MSR_RI)) {
+		/* If MSR_RI isn't set, we cannot recover */
+		pr_err("Machine check interrupt unrecoverable: MSR(RI=0)\n");
+		recovered = 0;
+	} else if (evt->disposition == MCE_DISPOSITION_RECOVERED) {
+		/* Platform corrected itself */
+		recovered = 1;
+	} else if (evt->severity == MCE_SEV_FATAL) {
+		/* Fatal machine check */
+		pr_err("Machine check interrupt is fatal\n");
+		recovered = 0;
+	}
+
+	if (!recovered && evt->sync_error) {
+		/*
+		 * Try to kill processes if we get a synchronous machine check
+		 * (e.g., one caused by execution of this instruction). This
+		 * will devolve into a panic if we try to kill init or are in
+		 * an interrupt etc.
+		 *
+		 * TODO: Queue up this address for hwpoisioning later.
+		 * TODO: This is not quite right for d-side machine
+		 *       checks ->nip is not necessarily the important
+		 *       address.
+		 */
+		if ((user_mode(regs))) {
+			_exception(SIGBUS, regs, BUS_MCEERR_AR, regs->nip);
+			recovered = 1;
+		} else if (die_will_crash()) {
+			/*
+			 * die() would kill the kernel, so better to go via
+			 * the platform reboot code that will log the
+			 * machine check.
+			 */
+			recovered = 0;
+		} else {
+			die("Machine check", regs, SIGBUS);
+			recovered = 1;
+		}
+	}
+
+	return recovered;
+}
+
+/*
+ * Handle a machine check.
+ *
+ * Note that on Power 4 and beyond Firmware Non-Maskable Interrupts (fwnmi)
+ * should be present.  If so the handler which called us tells us if the
+ * error was recovered (never true if RI=0).
+ *
+ * On hardware prior to Power 4 these exceptions were asynchronous which
+ * means we can't tell exactly where it occurred and so we can't recover.
+ */
+int pSeries_machine_check_exception(struct pt_regs *regs)
+{
+	struct machine_check_event evt;
+
+	if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
+		return 0;
+
+	/* Print things out */
+	if (evt.version != MCE_V1) {
+		pr_err("Machine Check Exception, Unknown event version %d !\n",
+		       evt.version);
+		return 0;
+	}
+	machine_check_print_event_info(&evt, user_mode(regs), false);
+
+	if (recover_mce(regs, &evt))
+		return 1;
+
+	return 0;
+}
+
+long pseries_machine_check_realmode(struct pt_regs *regs)
+{
+	struct rtas_error_log *errp;
+	int disposition;
+
+	if (fwnmi_active) {
+		errp = fwnmi_get_errinfo(regs);
+		/*
+		 * Call to fwnmi_release_errinfo() in real mode causes kernel
+		 * to panic. Hence we will call it as soon as we go into
+		 * virtual mode.
+		 */
+		disposition = mce_handle_error(regs, errp);
+		fwnmi_release_errinfo();
+
+		/* Queue irq work to log this rtas event later. */
+		irq_work_queue(&mce_errlog_process_work);
+
+		if (disposition == RTAS_DISP_FULLY_RECOVERED)
+			return 1;
+	}
+
+	return 0;
+}