1/*
  2 * NFIT - Machine Check Handler
  3 *
  4 * Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
  5 *
  6 * This program is free software; you can redistribute it and/or modify
  7 * it under the terms of version 2 of the GNU General Public License as
  8 * published by the Free Software Foundation.
  9 *
 10 * This program is distributed in the hope that it will be useful, but
 11 * WITHOUT ANY WARRANTY; without even the implied warranty of
 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 13 * General Public License for more details.
 14 */
 15#include <linux/notifier.h>
 16#include <linux/acpi.h>
 17#include <linux/nd.h>
 18#include <asm/mce.h>
 19#include "nfit.h"
 20
 21static int nfit_handle_mce(struct notifier_block *nb, unsigned long val,
 22			void *data)
 23{
 24	struct mce *mce = (struct mce *)data;
 25	struct acpi_nfit_desc *acpi_desc;
 26	struct nfit_spa *nfit_spa;
 27
 28	/* We only care about memory errors */
 29	if (!mce_is_memory_error(mce))
 30		return NOTIFY_DONE;
 31
 32	/*
 33	 * mce->addr contains the physical addr accessed that caused the
 34	 * machine check. We need to walk through the list of NFITs, and see
 35	 * if any of them matches that address, and only then start a scrub.
 36	 */
 37	mutex_lock(&acpi_desc_lock);
 38	list_for_each_entry(acpi_desc, &acpi_descs, list) {
 39		struct device *dev = acpi_desc->dev;
 40		int found_match = 0;
 41
 42		mutex_lock(&acpi_desc->init_mutex);
 43		list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
 44			struct acpi_nfit_system_address *spa = nfit_spa->spa;
 45
 46			if (nfit_spa_type(spa) != NFIT_SPA_PM)
 47				continue;
 48			/* find the spa that covers the mce addr */
 49			if (spa->address > mce->addr)
 50				continue;
 51			if ((spa->address + spa->length - 1) < mce->addr)
 52				continue;
 53			found_match = 1;
 54			dev_dbg(dev, "addr in SPA %d (0x%llx, 0x%llx)\n",
 55				spa->range_index, spa->address, spa->length);
 56			/*
 57			 * We can break at the first match because we're going
 58			 * to rescan all the SPA ranges. There shouldn't be any
 59			 * aliasing anyway.
 60			 */
 61			break;
 62		}
 63		mutex_unlock(&acpi_desc->init_mutex);
 64
 65		if (!found_match)
 66			continue;
 67
 68		/* If this fails due to an -ENOMEM, there is little we can do */
 69		nvdimm_bus_add_badrange(acpi_desc->nvdimm_bus,
 70				ALIGN(mce->addr, L1_CACHE_BYTES),
 71				L1_CACHE_BYTES);
 72		nvdimm_region_notify(nfit_spa->nd_region,
 73				NVDIMM_REVALIDATE_POISON);
 74
 75		if (acpi_desc->scrub_mode == HW_ERROR_SCRUB_ON) {
 76			/*
 77			 * We can ignore an -EBUSY here because if an ARS is
 78			 * already in progress, just let that be the last
 79			 * authoritative one
 80			 */
 81			acpi_nfit_ars_rescan(acpi_desc, 0);
 82		}
 83		break;
 84	}
 85
 86	mutex_unlock(&acpi_desc_lock);
 87	return NOTIFY_DONE;
 88}
 89
 90static struct notifier_block nfit_mce_dec = {
 91	.notifier_call	= nfit_handle_mce,
 92	.priority	= MCE_PRIO_NFIT,
 93};
 94
 95void nfit_mce_register(void)
 96{
 97	mce_register_decode_chain(&nfit_mce_dec);
 98}
 99
100void nfit_mce_unregister(void)
101{
102	mce_unregister_decode_chain(&nfit_mce_dec);
103}