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 <asm/mce.h> 18 #include "nfit.h" 19 20 static int nfit_handle_mce(struct notifier_block *nb, unsigned long val, 21 void *data) 22 { 23 struct mce *mce = (struct mce *)data; 24 struct acpi_nfit_desc *acpi_desc; 25 struct nfit_spa *nfit_spa; 26 27 /* We only care about memory errors */ 28 if (!(mce->status & MCACOD)) 29 return NOTIFY_DONE; 30 31 /* 32 * mce->addr contains the physical addr accessed that caused the 33 * machine check. We need to walk through the list of NFITs, and see 34 * if any of them matches that address, and only then start a scrub. 35 */ 36 mutex_lock(&acpi_desc_lock); 37 list_for_each_entry(acpi_desc, &acpi_descs, list) { 38 struct device *dev = acpi_desc->dev; 39 int found_match = 0; 40 41 mutex_lock(&acpi_desc->init_mutex); 42 list_for_each_entry(nfit_spa, &acpi_desc->spas, list) { 43 struct acpi_nfit_system_address *spa = nfit_spa->spa; 44 45 if (nfit_spa_type(spa) != NFIT_SPA_PM) 46 continue; 47 /* find the spa that covers the mce addr */ 48 if (spa->address > mce->addr) 49 continue; 50 if ((spa->address + spa->length - 1) < mce->addr) 51 continue; 52 found_match = 1; 53 dev_dbg(dev, "%s: addr in SPA %d (0x%llx, 0x%llx)\n", 54 __func__, spa->range_index, spa->address, 55 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 /* 66 * We can ignore an -EBUSY here because if an ARS is already 67 * in progress, just let that be the last authoritative one 68 */ 69 if (found_match) 70 acpi_nfit_ars_rescan(acpi_desc); 71 } 72 73 mutex_unlock(&acpi_desc_lock); 74 return NOTIFY_DONE; 75 } 76 77 static struct notifier_block nfit_mce_dec = { 78 .notifier_call = nfit_handle_mce, 79 }; 80 81 void nfit_mce_register(void) 82 { 83 mce_register_decode_chain(&nfit_mce_dec); 84 } 85 86 void nfit_mce_unregister(void) 87 { 88 mce_unregister_decode_chain(&nfit_mce_dec); 89 } 90