arch/powerpc/kernel/mce.c - linux - Git at Google

 /*
  * Machine check exception handling.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2 of the License, or
  * (at your option) any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  *
  * Copyright 2013 IBM Corporation
  * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
  */

 #undef DEBUG
 #define pr_fmt(fmt) "mce: " fmt

 #include <linux/types.h>
 #include <linux/ptrace.h>
 #include <linux/percpu.h>
 #include <linux/export.h>
 #include <linux/irq_work.h>
 #include <asm/mce.h>

 static DEFINE_PER_CPU(int, mce_nest_count);
 static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event);

 /* Queue for delayed MCE events. */
 static DEFINE_PER_CPU(int, mce_queue_count);
 static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event_queue);

 static void machine_check_process_queued_event(struct irq_work *work);
 struct irq_work mce_event_process_work = {
         .func = machine_check_process_queued_event,
 };

 static void mce_set_error_info(struct machine_check_event *mce,
 			       struct mce_error_info *mce_err)
 {
 	mce->error_type = mce_err->error_type;
 	switch (mce_err->error_type) {
 	case MCE_ERROR_TYPE_UE:
 		mce->u.ue_error.ue_error_type = mce_err->u.ue_error_type;
 		break;
 	case MCE_ERROR_TYPE_SLB:
 		mce->u.slb_error.slb_error_type = mce_err->u.slb_error_type;
 		break;
 	case MCE_ERROR_TYPE_ERAT:
 		mce->u.erat_error.erat_error_type = mce_err->u.erat_error_type;
 		break;
 	case MCE_ERROR_TYPE_TLB:
 		mce->u.tlb_error.tlb_error_type = mce_err->u.tlb_error_type;
 		break;
 	case MCE_ERROR_TYPE_UNKNOWN:
 	default:
 		break;
 	}
 }

 /*
  * Decode and save high level MCE information into per cpu buffer which
  * is an array of machine_check_event structure.
  */
 void save_mce_event(struct pt_regs *regs, long handled,
 		    struct mce_error_info *mce_err,
 		    uint64_t nip, uint64_t addr)
 {
 	uint64_t srr1;
 	int index = __this_cpu_inc_return(mce_nest_count);
 	struct machine_check_event *mce = this_cpu_ptr(&mce_event[index]);

 	/*
 	 * Return if we don't have enough space to log mce event.
 	 * mce_nest_count may go beyond MAX_MC_EVT but that's ok,
 	 * the check below will stop buffer overrun.
 	 */
 	if (index >= MAX_MC_EVT)
 		return;

 	/* Populate generic machine check info */
 	mce->version = MCE_V1;
 	mce->srr0 = nip;
 	mce->srr1 = regs->msr;
 	mce->gpr3 = regs->gpr[3];
 	mce->in_use = 1;

 	mce->initiator = MCE_INITIATOR_CPU;
 	if (handled)
 		mce->disposition = MCE_DISPOSITION_RECOVERED;
 	else
 		mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
 	mce->severity = MCE_SEV_ERROR_SYNC;

 	srr1 = regs->msr;

 	/*
 	 * Populate the mce error_type and type-specific error_type.
 	 */
 	mce_set_error_info(mce, mce_err);

 	if (!addr)
 		return;

 	if (mce->error_type == MCE_ERROR_TYPE_TLB) {
 		mce->u.tlb_error.effective_address_provided = true;
 		mce->u.tlb_error.effective_address = addr;
 	} else if (mce->error_type == MCE_ERROR_TYPE_SLB) {
 		mce->u.slb_error.effective_address_provided = true;
 		mce->u.slb_error.effective_address = addr;
 	} else if (mce->error_type == MCE_ERROR_TYPE_ERAT) {
 		mce->u.erat_error.effective_address_provided = true;
 		mce->u.erat_error.effective_address = addr;
 	} else if (mce->error_type == MCE_ERROR_TYPE_UE) {
 		mce->u.ue_error.effective_address_provided = true;
 		mce->u.ue_error.effective_address = addr;
 	}
 	return;
 }

 /*
  * get_mce_event:
  *	mce	Pointer to machine_check_event structure to be filled.
  *	release Flag to indicate whether to free the event slot or not.
  *		0 <= do not release the mce event. Caller will invoke
  *		     release_mce_event() once event has been consumed.
  *		1 <= release the slot.
  *
  *	return	1 = success
  *		0 = failure
  *
  * get_mce_event() will be called by platform specific machine check
  * handle routine and in KVM.
  * When we call get_mce_event(), we are still in interrupt context and
  * preemption will not be scheduled until ret_from_expect() routine
  * is called.
  */
 int get_mce_event(struct machine_check_event *mce, bool release)
 {
 	int index = __this_cpu_read(mce_nest_count) - 1;
 	struct machine_check_event *mc_evt;
 	int ret = 0;

 	/* Sanity check */
 	if (index < 0)
 		return ret;

 	/* Check if we have MCE info to process. */
 	if (index < MAX_MC_EVT) {
 		mc_evt = this_cpu_ptr(&mce_event[index]);
 		/* Copy the event structure and release the original */
 		if (mce)
 			*mce = *mc_evt;
 		if (release)
 			mc_evt->in_use = 0;
 		ret = 1;
 	}
 	/* Decrement the count to free the slot. */
 	if (release)
 		__this_cpu_dec(mce_nest_count);

 	return ret;
 }

 void release_mce_event(void)
 {
 	get_mce_event(NULL, true);
 }

 /*
  * Queue up the MCE event which then can be handled later.
  */
 void machine_check_queue_event(void)
 {
 	int index;
 	struct machine_check_event evt;

 	if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
 		return;

 	index = __this_cpu_inc_return(mce_queue_count);
 	/* If queue is full, just return for now. */
 	if (index >= MAX_MC_EVT) {
 		__this_cpu_dec(mce_queue_count);
 		return;
 	}
 	memcpy(this_cpu_ptr(&mce_event_queue[index]), &evt, sizeof(evt));

 	/* Queue irq work to process this event later. */
 	irq_work_queue(&mce_event_process_work);
 }

 /*
  * process pending MCE event from the mce event queue. This function will be
  * called during syscall exit.
  */
 static void machine_check_process_queued_event(struct irq_work *work)
 {
 	int index;

 	/*
 	 * For now just print it to console.
 	 * TODO: log this error event to FSP or nvram.
 	 */
 	while (__this_cpu_read(mce_queue_count) > 0) {
 		index = __this_cpu_read(mce_queue_count) - 1;
 		machine_check_print_event_info(
 				this_cpu_ptr(&mce_event_queue[index]));
 		__this_cpu_dec(mce_queue_count);
 	}
 }

 void machine_check_print_event_info(struct machine_check_event *evt)
 {
 	const char *level, *sevstr, *subtype;
 	static const char *mc_ue_types[] = {
 		"Indeterminate",
 		"Instruction fetch",
 		"Page table walk ifetch",
 		"Load/Store",
 		"Page table walk Load/Store",
 	};
 	static const char *mc_slb_types[] = {
 		"Indeterminate",
 		"Parity",
 		"Multihit",
 	};
 	static const char *mc_erat_types[] = {
 		"Indeterminate",
 		"Parity",
 		"Multihit",
 	};
 	static const char *mc_tlb_types[] = {
 		"Indeterminate",
 		"Parity",
 		"Multihit",
 	};

 	/* Print things out */
 	if (evt->version != MCE_V1) {
 		pr_err("Machine Check Exception, Unknown event version %d !\n",
 		       evt->version);
 		return;
 	}
 	switch (evt->severity) {
 	case MCE_SEV_NO_ERROR:
 		level = KERN_INFO;
 		sevstr = "Harmless";
 		break;
 	case MCE_SEV_WARNING:
 		level = KERN_WARNING;
 		sevstr = "";
 		break;
 	case MCE_SEV_ERROR_SYNC:
 		level = KERN_ERR;
 		sevstr = "Severe";
 		break;
 	case MCE_SEV_FATAL:
 	default:
 		level = KERN_ERR;
 		sevstr = "Fatal";
 		break;
 	}

 	printk("%s%s Machine check interrupt [%s]\n", level, sevstr,
 	       evt->disposition == MCE_DISPOSITION_RECOVERED ?
 	       "Recovered" : "[Not recovered");
 	printk("%s  Initiator: %s\n", level,
 	       evt->initiator == MCE_INITIATOR_CPU ? "CPU" : "Unknown");
 	switch (evt->error_type) {
 	case MCE_ERROR_TYPE_UE:
 		subtype = evt->u.ue_error.ue_error_type <
 			ARRAY_SIZE(mc_ue_types) ?
 			mc_ue_types[evt->u.ue_error.ue_error_type]
 			: "Unknown";
 		printk("%s  Error type: UE [%s]\n", level, subtype);
 		if (evt->u.ue_error.effective_address_provided)
 			printk("%s    Effective address: %016llx\n",
 			       level, evt->u.ue_error.effective_address);
 		if (evt->u.ue_error.physical_address_provided)
 			printk("%s      Physial address: %016llx\n",
 			       level, evt->u.ue_error.physical_address);
 		break;
 	case MCE_ERROR_TYPE_SLB:
 		subtype = evt->u.slb_error.slb_error_type <
 			ARRAY_SIZE(mc_slb_types) ?
 			mc_slb_types[evt->u.slb_error.slb_error_type]
 			: "Unknown";
 		printk("%s  Error type: SLB [%s]\n", level, subtype);
 		if (evt->u.slb_error.effective_address_provided)
 			printk("%s    Effective address: %016llx\n",
 			       level, evt->u.slb_error.effective_address);
 		break;
 	case MCE_ERROR_TYPE_ERAT:
 		subtype = evt->u.erat_error.erat_error_type <
 			ARRAY_SIZE(mc_erat_types) ?
 			mc_erat_types[evt->u.erat_error.erat_error_type]
 			: "Unknown";
 		printk("%s  Error type: ERAT [%s]\n", level, subtype);
 		if (evt->u.erat_error.effective_address_provided)
 			printk("%s    Effective address: %016llx\n",
 			       level, evt->u.erat_error.effective_address);
 		break;
 	case MCE_ERROR_TYPE_TLB:
 		subtype = evt->u.tlb_error.tlb_error_type <
 			ARRAY_SIZE(mc_tlb_types) ?
 			mc_tlb_types[evt->u.tlb_error.tlb_error_type]
 			: "Unknown";
 		printk("%s  Error type: TLB [%s]\n", level, subtype);
 		if (evt->u.tlb_error.effective_address_provided)
 			printk("%s    Effective address: %016llx\n",
 			       level, evt->u.tlb_error.effective_address);
 		break;
 	default:
 	case MCE_ERROR_TYPE_UNKNOWN:
 		printk("%s  Error type: Unknown\n", level);
 		break;
 	}
 }

 uint64_t get_mce_fault_addr(struct machine_check_event *evt)
 {
 	switch (evt->error_type) {
 	case MCE_ERROR_TYPE_UE:
 		if (evt->u.ue_error.effective_address_provided)
 			return evt->u.ue_error.effective_address;
 		break;
 	case MCE_ERROR_TYPE_SLB:
 		if (evt->u.slb_error.effective_address_provided)
 			return evt->u.slb_error.effective_address;
 		break;
 	case MCE_ERROR_TYPE_ERAT:
 		if (evt->u.erat_error.effective_address_provided)
 			return evt->u.erat_error.effective_address;
 		break;
 	case MCE_ERROR_TYPE_TLB:
 		if (evt->u.tlb_error.effective_address_provided)
 			return evt->u.tlb_error.effective_address;
 		break;
 	default:
 	case MCE_ERROR_TYPE_UNKNOWN:
 		break;
 	}
 	return 0;
 }
 EXPORT_SYMBOL(get_mce_fault_addr);
	/*
	* Machine check exception handling.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2 of the License, or
	* (at your option) any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	*
	* Copyright 2013 IBM Corporation
	* Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
	*/

	#undef DEBUG
	#define pr_fmt(fmt) "mce: " fmt

	#include <linux/types.h>
	#include <linux/ptrace.h>
	#include <linux/percpu.h>
	#include <linux/export.h>
	#include <linux/irq_work.h>
	#include <asm/mce.h>

	static DEFINE_PER_CPU(int, mce_nest_count);
	static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event);

	/* Queue for delayed MCE events. */
	static DEFINE_PER_CPU(int, mce_queue_count);
	static DEFINE_PER_CPU(struct machine_check_event[MAX_MC_EVT], mce_event_queue);

	static void machine_check_process_queued_event(struct irq_work *work);
	struct irq_work mce_event_process_work = {
	.func = machine_check_process_queued_event,
	};

	static void mce_set_error_info(struct machine_check_event *mce,
	struct mce_error_info *mce_err)
	{
	mce->error_type = mce_err->error_type;
	switch (mce_err->error_type) {
	case MCE_ERROR_TYPE_UE:
	mce->u.ue_error.ue_error_type = mce_err->u.ue_error_type;
	break;
	case MCE_ERROR_TYPE_SLB:
	mce->u.slb_error.slb_error_type = mce_err->u.slb_error_type;
	break;
	case MCE_ERROR_TYPE_ERAT:
	mce->u.erat_error.erat_error_type = mce_err->u.erat_error_type;
	break;
	case MCE_ERROR_TYPE_TLB:
	mce->u.tlb_error.tlb_error_type = mce_err->u.tlb_error_type;
	break;
	case MCE_ERROR_TYPE_UNKNOWN:
	default:
	break;
	}
	}

	/*
	* Decode and save high level MCE information into per cpu buffer which
	* is an array of machine_check_event structure.
	*/
	void save_mce_event(struct pt_regs *regs, long handled,
	struct mce_error_info *mce_err,
	uint64_t nip, uint64_t addr)
	{
	uint64_t srr1;
	int index = __this_cpu_inc_return(mce_nest_count);
	struct machine_check_event *mce = this_cpu_ptr(&mce_event[index]);

	/*
	* Return if we don't have enough space to log mce event.
	* mce_nest_count may go beyond MAX_MC_EVT but that's ok,
	* the check below will stop buffer overrun.
	*/
	if (index >= MAX_MC_EVT)
	return;

	/* Populate generic machine check info */
	mce->version = MCE_V1;
	mce->srr0 = nip;
	mce->srr1 = regs->msr;
	mce->gpr3 = regs->gpr[3];
	mce->in_use = 1;

	mce->initiator = MCE_INITIATOR_CPU;
	if (handled)
	mce->disposition = MCE_DISPOSITION_RECOVERED;
	else
	mce->disposition = MCE_DISPOSITION_NOT_RECOVERED;
	mce->severity = MCE_SEV_ERROR_SYNC;

	srr1 = regs->msr;

	/*
	* Populate the mce error_type and type-specific error_type.
	*/
	mce_set_error_info(mce, mce_err);

	if (!addr)
	return;

	if (mce->error_type == MCE_ERROR_TYPE_TLB) {
	mce->u.tlb_error.effective_address_provided = true;
	mce->u.tlb_error.effective_address = addr;
	} else if (mce->error_type == MCE_ERROR_TYPE_SLB) {
	mce->u.slb_error.effective_address_provided = true;
	mce->u.slb_error.effective_address = addr;
	} else if (mce->error_type == MCE_ERROR_TYPE_ERAT) {
	mce->u.erat_error.effective_address_provided = true;
	mce->u.erat_error.effective_address = addr;
	} else if (mce->error_type == MCE_ERROR_TYPE_UE) {
	mce->u.ue_error.effective_address_provided = true;
	mce->u.ue_error.effective_address = addr;
	}
	return;
	}

	/*
	* get_mce_event:
	* mce Pointer to machine_check_event structure to be filled.
	* release Flag to indicate whether to free the event slot or not.
	* 0 <= do not release the mce event. Caller will invoke
	* release_mce_event() once event has been consumed.
	* 1 <= release the slot.
	*
	* return 1 = success
	* 0 = failure
	*
	* get_mce_event() will be called by platform specific machine check
	* handle routine and in KVM.
	* When we call get_mce_event(), we are still in interrupt context and
	* preemption will not be scheduled until ret_from_expect() routine
	* is called.
	*/
	int get_mce_event(struct machine_check_event *mce, bool release)
	{
	int index = __this_cpu_read(mce_nest_count) - 1;
	struct machine_check_event *mc_evt;
	int ret = 0;

	/* Sanity check */
	if (index < 0)
	return ret;

	/* Check if we have MCE info to process. */
	if (index < MAX_MC_EVT) {
	mc_evt = this_cpu_ptr(&mce_event[index]);
	/* Copy the event structure and release the original */
	if (mce)
	mce = mc_evt;
	if (release)
	mc_evt->in_use = 0;
	ret = 1;
	}
	/* Decrement the count to free the slot. */
	if (release)
	__this_cpu_dec(mce_nest_count);

	return ret;
	}

	void release_mce_event(void)
	{
	get_mce_event(NULL, true);
	}

	/*
	* Queue up the MCE event which then can be handled later.
	*/
	void machine_check_queue_event(void)
	{
	int index;
	struct machine_check_event evt;

	if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
	return;

	index = __this_cpu_inc_return(mce_queue_count);
	/* If queue is full, just return for now. */
	if (index >= MAX_MC_EVT) {
	__this_cpu_dec(mce_queue_count);
	return;
	}
	memcpy(this_cpu_ptr(&mce_event_queue[index]), &evt, sizeof(evt));

	/* Queue irq work to process this event later. */
	irq_work_queue(&mce_event_process_work);
	}

	/*
	* process pending MCE event from the mce event queue. This function will be
	* called during syscall exit.
	*/
	static void machine_check_process_queued_event(struct irq_work *work)
	{
	int index;

	/*
	* For now just print it to console.
	* TODO: log this error event to FSP or nvram.
	*/
	while (__this_cpu_read(mce_queue_count) > 0) {
	index = __this_cpu_read(mce_queue_count) - 1;
	machine_check_print_event_info(
	this_cpu_ptr(&mce_event_queue[index]));
	__this_cpu_dec(mce_queue_count);
	}
	}

	void machine_check_print_event_info(struct machine_check_event *evt)
	{
	const char level, sevstr, *subtype;
	static const char *mc_ue_types[] = {
	"Indeterminate",
	"Instruction fetch",
	"Page table walk ifetch",
	"Load/Store",
	"Page table walk Load/Store",
	};
	static const char *mc_slb_types[] = {
	"Indeterminate",
	"Parity",
	"Multihit",
	};
	static const char *mc_erat_types[] = {
	"Indeterminate",
	"Parity",
	"Multihit",
	};
	static const char *mc_tlb_types[] = {
	"Indeterminate",
	"Parity",
	"Multihit",
	};

	/* Print things out */
	if (evt->version != MCE_V1) {
	pr_err("Machine Check Exception, Unknown event version %d !\n",
	evt->version);
	return;
	}
	switch (evt->severity) {
	case MCE_SEV_NO_ERROR:
	level = KERN_INFO;
	sevstr = "Harmless";
	break;
	case MCE_SEV_WARNING:
	level = KERN_WARNING;
	sevstr = "";
	break;
	case MCE_SEV_ERROR_SYNC:
	level = KERN_ERR;
	sevstr = "Severe";
	break;
	case MCE_SEV_FATAL:
	default:
	level = KERN_ERR;
	sevstr = "Fatal";
	break;
	}

	printk("%s%s Machine check interrupt [%s]\n", level, sevstr,
	evt->disposition == MCE_DISPOSITION_RECOVERED ?
	"Recovered" : "[Not recovered");
	printk("%s Initiator: %s\n", level,
	evt->initiator == MCE_INITIATOR_CPU ? "CPU" : "Unknown");
	switch (evt->error_type) {
	case MCE_ERROR_TYPE_UE:
	subtype = evt->u.ue_error.ue_error_type <
	ARRAY_SIZE(mc_ue_types) ?
	mc_ue_types[evt->u.ue_error.ue_error_type]
	: "Unknown";
	printk("%s Error type: UE [%s]\n", level, subtype);
	if (evt->u.ue_error.effective_address_provided)
	printk("%s Effective address: %016llx\n",
	level, evt->u.ue_error.effective_address);
	if (evt->u.ue_error.physical_address_provided)
	printk("%s Physial address: %016llx\n",
	level, evt->u.ue_error.physical_address);
	break;
	case MCE_ERROR_TYPE_SLB:
	subtype = evt->u.slb_error.slb_error_type <
	ARRAY_SIZE(mc_slb_types) ?
	mc_slb_types[evt->u.slb_error.slb_error_type]
	: "Unknown";
	printk("%s Error type: SLB [%s]\n", level, subtype);
	if (evt->u.slb_error.effective_address_provided)
	printk("%s Effective address: %016llx\n",
	level, evt->u.slb_error.effective_address);
	break;
	case MCE_ERROR_TYPE_ERAT:
	subtype = evt->u.erat_error.erat_error_type <
	ARRAY_SIZE(mc_erat_types) ?
	mc_erat_types[evt->u.erat_error.erat_error_type]
	: "Unknown";
	printk("%s Error type: ERAT [%s]\n", level, subtype);
	if (evt->u.erat_error.effective_address_provided)
	printk("%s Effective address: %016llx\n",
	level, evt->u.erat_error.effective_address);
	break;
	case MCE_ERROR_TYPE_TLB:
	subtype = evt->u.tlb_error.tlb_error_type <
	ARRAY_SIZE(mc_tlb_types) ?
	mc_tlb_types[evt->u.tlb_error.tlb_error_type]
	: "Unknown";
	printk("%s Error type: TLB [%s]\n", level, subtype);
	if (evt->u.tlb_error.effective_address_provided)
	printk("%s Effective address: %016llx\n",
	level, evt->u.tlb_error.effective_address);
	break;
	default:
	case MCE_ERROR_TYPE_UNKNOWN:
	printk("%s Error type: Unknown\n", level);
	break;
	}
	}

	uint64_t get_mce_fault_addr(struct machine_check_event *evt)
	{
	switch (evt->error_type) {
	case MCE_ERROR_TYPE_UE:
	if (evt->u.ue_error.effective_address_provided)
	return evt->u.ue_error.effective_address;
	break;
	case MCE_ERROR_TYPE_SLB:
	if (evt->u.slb_error.effective_address_provided)
	return evt->u.slb_error.effective_address;
	break;
	case MCE_ERROR_TYPE_ERAT:
	if (evt->u.erat_error.effective_address_provided)
	return evt->u.erat_error.effective_address;
	break;
	case MCE_ERROR_TYPE_TLB:
	if (evt->u.tlb_error.effective_address_provided)
	return evt->u.tlb_error.effective_address;
	break;
	default:
	case MCE_ERROR_TYPE_UNKNOWN:
	break;
	}
	return 0;
	}
	EXPORT_SYMBOL(get_mce_fault_addr);