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
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 struct device *dev = acpi_desc->dev;
36 int found_match = 0;
37
38 mutex_lock(&acpi_desc->init_mutex);
39 list_for_each_entry(nfit_spa, &acpi_desc->spas, list) {
40 struct acpi_nfit_system_address *spa = nfit_spa->spa;
41
42 if (nfit_spa_type(spa) != NFIT_SPA_PM)
43 continue;
44 /* find the spa that covers the mce addr */
45 if (spa->address > mce->addr)
46 continue;
47 if ((spa->address + spa->length - 1) < mce->addr)
48 continue;
49 found_match = 1;
50 dev_dbg(dev, "addr in SPA %d (0x%llx, 0x%llx)\n",
51 spa->range_index, spa->address, spa->length);
52 /*
53 * We can break at the first match because we're going
54 * to rescan all the SPA ranges. There shouldn't be any
55 * aliasing anyway.
56 */
57 break;
58 }
59 mutex_unlock(&acpi_desc->init_mutex);
60
61 if (!found_match)
62 continue;
63
64 /* If this fails due to an -ENOMEM, there is little we can do */
65 nvdimm_bus_add_badrange(acpi_desc->nvdimm_bus,
66 ALIGN(mce->addr, L1_CACHE_BYTES),
67 L1_CACHE_BYTES);
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 break;
80 }
81
82 mutex_unlock(&acpi_desc_lock);
83 return NOTIFY_DONE;
84 }
85
86 static struct notifier_block nfit_mce_dec = {
87 .notifier_call = nfit_handle_mce,
88 .priority = MCE_PRIO_NFIT,
89 };
90
91 void nfit_mce_register(void)
92 {
93 mce_register_decode_chain(&nfit_mce_dec);
94 }
95
96 void nfit_mce_unregister(void)
97 {
98 mce_unregister_decode_chain(&nfit_mce_dec);
99 }