1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * NFIT - Machine Check Handler
4 *
5 * Copyright(c) 2013-2016 Intel Corporation. All rights reserved.
6 */
7 #include <linux/notifier.h>
8 #include <linux/acpi.h>
9 #include <linux/nd.h>
10 #include <asm/mce.h>
11 #include "nfit.h"
12
nfit_handle_mce(struct notifier_block * nb,unsigned long val,void * data)13 static int nfit_handle_mce(struct notifier_block *nb, unsigned long val,
14 void *data)
15 {
16 struct mce *mce = (struct mce *)data;
17 struct acpi_nfit_desc *acpi_desc;
18 struct nfit_spa *nfit_spa;
19
20 /* We only care about uncorrectable memory errors */
21 if (!mce_is_memory_error(mce) || mce_is_correctable(mce))
22 return NOTIFY_DONE;
23
24 /* Verify the address reported in the MCE is valid. */
25 if (!mce_usable_address(mce))
26 return NOTIFY_DONE;
27
28 /*
29 * mce->addr contains the physical addr accessed that caused the
30 * machine check. We need to walk through the list of NFITs, and see
31 * if any of them matches that address, and only then start a scrub.
32 */
33 mutex_lock(&acpi_desc_lock);
34 list_for_each_entry(acpi_desc, &acpi_descs, list) {
35 unsigned int align = 1UL << MCI_MISC_ADDR_LSB(mce->misc);
36 struct device *dev = acpi_desc->dev;
37 int found_match = 0;
38
39 mutex_lock(&acpi_desc->init_mutex);
40 list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
41 struct acpi_nfit_system_address *spa = nfit_spa->spa;
42
43 if (nfit_spa_type(spa) != NFIT_SPA_PM)
44 continue;
45 /* find the spa that covers the mce addr */
46 if (spa->address > mce->addr)
47 continue;
48 if ((spa->address + spa->length - 1) < mce->addr)
49 continue;
50 found_match = 1;
51 dev_dbg(dev, "addr in SPA %d (0x%llx, 0x%llx)\n",
52 spa->range_index, spa->address, spa->length);
53 /*
54 * We can break at the first match because we're going
55 * to rescan all the SPA ranges. There shouldn't be any
56 * aliasing anyway.
57 */
58 break;
59 }
60 mutex_unlock(&acpi_desc->init_mutex);
61
62 if (!found_match)
63 continue;
64
65 /* If this fails due to an -ENOMEM, there is little we can do */
66 nvdimm_bus_add_badrange(acpi_desc->nvdimm_bus,
67 ALIGN_DOWN(mce->addr, align), align);
68 nvdimm_region_notify(nfit_spa->nd_region,
69 NVDIMM_REVALIDATE_POISON);
70
71 if (acpi_desc->scrub_mode == HW_ERROR_SCRUB_ON) {
72 /*
73 * We can ignore an -EBUSY here because if an ARS is
74 * already in progress, just let that be the last
75 * authoritative one
76 */
77 acpi_nfit_ars_rescan(acpi_desc, 0);
78 }
79 mce->kflags |= MCE_HANDLED_NFIT;
80 break;
81 }
82
83 mutex_unlock(&acpi_desc_lock);
84 return NOTIFY_DONE;
85 }
86
87 static struct notifier_block nfit_mce_dec = {
88 .notifier_call = nfit_handle_mce,
89 .priority = MCE_PRIO_NFIT,
90 };
91
nfit_mce_register(void)92 void nfit_mce_register(void)
93 {
94 mce_register_decode_chain(&nfit_mce_dec);
95 }
96
nfit_mce_unregister(void)97 void nfit_mce_unregister(void)
98 {
99 mce_unregister_decode_chain(&nfit_mce_dec);
100 }
101