1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Extended Error Log driver
4 *
5 * Copyright (C) 2013 Intel Corp.
6 * Author: Chen, Gong <gong.chen@intel.com>
7 */
8
9#include <linux/module.h>
10#include <linux/acpi.h>
11#include <linux/cper.h>
12#include <linux/ratelimit.h>
13#include <linux/edac.h>
14#include <linux/ras.h>
15#include <acpi/ghes.h>
16#include <asm/cpu.h>
17#include <asm/mce.h>
18
19#include "apei/apei-internal.h"
20#include <ras/ras_event.h>
21
22#define EXT_ELOG_ENTRY_MASK GENMASK_ULL(51, 0) /* elog entry address mask */
23
24#define EXTLOG_DSM_REV 0x0
25#define EXTLOG_FN_ADDR 0x1
26
27#define FLAG_OS_OPTIN BIT(0)
28#define ELOG_ENTRY_VALID (1ULL<<63)
29#define ELOG_ENTRY_LEN 0x1000
30
31#define EMCA_BUG \
32 "Can not request iomem region <0x%016llx-0x%016llx> - eMCA disabled\n"
33
34struct extlog_l1_head {
35 u32 ver; /* Header Version */
36 u32 hdr_len; /* Header Length */
37 u64 total_len; /* entire L1 Directory length including this header */
38 u64 elog_base; /* MCA Error Log Directory base address */
39 u64 elog_len; /* MCA Error Log Directory length */
40 u32 flags; /* bit 0 - OS/VMM Opt-in */
41 u8 rev0[12];
42 u32 entries; /* Valid L1 Directory entries per logical processor */
43 u8 rev1[12];
44};
45
46static u8 extlog_dsm_uuid[] __initdata = "663E35AF-CC10-41A4-88EA-5470AF055295";
47
48/* L1 table related physical address */
49static u64 elog_base;
50static size_t elog_size;
51static u64 l1_dirbase;
52static size_t l1_size;
53
54/* L1 table related virtual address */
55static void __iomem *extlog_l1_addr;
56static void __iomem *elog_addr;
57
58static void *elog_buf;
59
60static u64 *l1_entry_base;
61static u32 l1_percpu_entry;
62
63#define ELOG_IDX(cpu, bank) \
64 (cpu_physical_id(cpu) * l1_percpu_entry + (bank))
65
66#define ELOG_ENTRY_DATA(idx) \
67 (*(l1_entry_base + (idx)))
68
69#define ELOG_ENTRY_ADDR(phyaddr) \
70 (phyaddr - elog_base + (u8 *)elog_addr)
71
72static struct acpi_hest_generic_status *extlog_elog_entry_check(int cpu, int bank)
73{
74 int idx;
75 u64 data;
76 struct acpi_hest_generic_status *estatus;
77
78 WARN_ON(cpu < 0);
79 idx = ELOG_IDX(cpu, bank);
80 data = ELOG_ENTRY_DATA(idx);
81 if ((data & ELOG_ENTRY_VALID) == 0)
82 return NULL;
83
84 data &= EXT_ELOG_ENTRY_MASK;
85 estatus = (struct acpi_hest_generic_status *)ELOG_ENTRY_ADDR(data);
86
87 /* if no valid data in elog entry, just return */
88 if (estatus->block_status == 0)
89 return NULL;
90
91 return estatus;
92}
93
94static void __print_extlog_rcd(const char *pfx,
95 struct acpi_hest_generic_status *estatus, int cpu)
96{
97 static atomic_t seqno;
98 unsigned int curr_seqno;
99 char pfx_seq[64];
100
101 if (!pfx) {
102 if (estatus->error_severity <= CPER_SEV_CORRECTED)
103 pfx = KERN_INFO;
104 else
105 pfx = KERN_ERR;
106 }
107 curr_seqno = atomic_inc_return(v: &seqno);
108 snprintf(buf: pfx_seq, size: sizeof(pfx_seq), fmt: "%s{%u}", pfx, curr_seqno);
109 printk("%s""Hardware error detected on CPU%d\n", pfx_seq, cpu);
110 cper_estatus_print(pfx: pfx_seq, estatus);
111}
112
113static int print_extlog_rcd(const char *pfx,
114 struct acpi_hest_generic_status *estatus, int cpu)
115{
116 /* Not more than 2 messages every 5 seconds */
117 static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
118 static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
119 struct ratelimit_state *ratelimit;
120
121 if (estatus->error_severity == CPER_SEV_CORRECTED ||
122 (estatus->error_severity == CPER_SEV_INFORMATIONAL))
123 ratelimit = &ratelimit_corrected;
124 else
125 ratelimit = &ratelimit_uncorrected;
126 if (__ratelimit(ratelimit)) {
127 __print_extlog_rcd(pfx, estatus, cpu);
128 return 0;
129 }
130
131 return 1;
132}
133
134static int extlog_print(struct notifier_block *nb, unsigned long val,
135 void *data)
136{
137 struct mce *mce = (struct mce *)data;
138 int bank = mce->bank;
139 int cpu = mce->extcpu;
140 struct acpi_hest_generic_status *estatus, *tmp;
141 struct acpi_hest_generic_data *gdata;
142 const guid_t *fru_id;
143 char *fru_text;
144 guid_t *sec_type;
145 static u32 err_seq;
146
147 estatus = extlog_elog_entry_check(cpu, bank);
148 if (estatus == NULL || (mce->kflags & MCE_HANDLED_CEC))
149 return NOTIFY_DONE;
150
151 memcpy(elog_buf, (void *)estatus, ELOG_ENTRY_LEN);
152 /* clear record status to enable BIOS to update it again */
153 estatus->block_status = 0;
154
155 tmp = (struct acpi_hest_generic_status *)elog_buf;
156
157 if (!ras_userspace_consumers()) {
158 print_extlog_rcd(NULL, estatus: tmp, cpu);
159 goto out;
160 }
161
162 /* log event via trace */
163 err_seq++;
164 apei_estatus_for_each_section(tmp, gdata) {
165 if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
166 fru_id = (guid_t *)gdata->fru_id;
167 else
168 fru_id = &guid_null;
169 if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
170 fru_text = gdata->fru_text;
171 else
172 fru_text = "";
173 sec_type = (guid_t *)gdata->section_type;
174 if (guid_equal(u1: sec_type, u2: &CPER_SEC_PLATFORM_MEM)) {
175 struct cper_sec_mem_err *mem = acpi_hest_get_payload(gdata);
176
177 if (gdata->error_data_length >= sizeof(*mem))
178 trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
179 sev: (u8)gdata->error_severity);
180 }
181 }
182
183out:
184 mce->kflags |= MCE_HANDLED_EXTLOG;
185 return NOTIFY_OK;
186}
187
188static bool __init extlog_get_l1addr(void)
189{
190 guid_t guid;
191 acpi_handle handle;
192 union acpi_object *obj;
193
194 if (guid_parse(uuid: extlog_dsm_uuid, u: &guid))
195 return false;
196 if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
197 return false;
198 if (!acpi_check_dsm(handle, guid: &guid, EXTLOG_DSM_REV, funcs: 1 << EXTLOG_FN_ADDR))
199 return false;
200 obj = acpi_evaluate_dsm_typed(handle, guid: &guid, EXTLOG_DSM_REV,
201 EXTLOG_FN_ADDR, NULL, ACPI_TYPE_INTEGER);
202 if (!obj) {
203 return false;
204 } else {
205 l1_dirbase = obj->integer.value;
206 ACPI_FREE(obj);
207 }
208
209 /* Spec says L1 directory must be 4K aligned, bail out if it isn't */
210 if (l1_dirbase & ((1 << 12) - 1)) {
211 pr_warn(FW_BUG "L1 Directory is invalid at physical %llx\n",
212 l1_dirbase);
213 return false;
214 }
215
216 return true;
217}
218static struct notifier_block extlog_mce_dec = {
219 .notifier_call = extlog_print,
220 .priority = MCE_PRIO_EXTLOG,
221};
222
223static int __init extlog_init(void)
224{
225 struct extlog_l1_head *l1_head;
226 void __iomem *extlog_l1_hdr;
227 size_t l1_hdr_size;
228 struct resource *r;
229 u64 cap;
230 int rc;
231
232 if (rdmsrl_safe(MSR_IA32_MCG_CAP, p: &cap) ||
233 !(cap & MCG_ELOG_P) ||
234 !extlog_get_l1addr())
235 return -ENODEV;
236
237 rc = -EINVAL;
238 /* get L1 header to fetch necessary information */
239 l1_hdr_size = sizeof(struct extlog_l1_head);
240 r = request_mem_region(l1_dirbase, l1_hdr_size, "L1 DIR HDR");
241 if (!r) {
242 pr_warn(FW_BUG EMCA_BUG,
243 (unsigned long long)l1_dirbase,
244 (unsigned long long)l1_dirbase + l1_hdr_size);
245 goto err;
246 }
247
248 extlog_l1_hdr = acpi_os_map_iomem(phys: l1_dirbase, size: l1_hdr_size);
249 l1_head = (struct extlog_l1_head *)extlog_l1_hdr;
250 l1_size = l1_head->total_len;
251 l1_percpu_entry = l1_head->entries;
252 elog_base = l1_head->elog_base;
253 elog_size = l1_head->elog_len;
254 acpi_os_unmap_iomem(virt: extlog_l1_hdr, size: l1_hdr_size);
255 release_mem_region(l1_dirbase, l1_hdr_size);
256
257 /* remap L1 header again based on completed information */
258 r = request_mem_region(l1_dirbase, l1_size, "L1 Table");
259 if (!r) {
260 pr_warn(FW_BUG EMCA_BUG,
261 (unsigned long long)l1_dirbase,
262 (unsigned long long)l1_dirbase + l1_size);
263 goto err;
264 }
265 extlog_l1_addr = acpi_os_map_iomem(phys: l1_dirbase, size: l1_size);
266 l1_entry_base = (u64 *)((u8 *)extlog_l1_addr + l1_hdr_size);
267
268 /* remap elog table */
269 r = request_mem_region(elog_base, elog_size, "Elog Table");
270 if (!r) {
271 pr_warn(FW_BUG EMCA_BUG,
272 (unsigned long long)elog_base,
273 (unsigned long long)elog_base + elog_size);
274 goto err_release_l1_dir;
275 }
276 elog_addr = acpi_os_map_iomem(phys: elog_base, size: elog_size);
277
278 rc = -ENOMEM;
279 /* allocate buffer to save elog record */
280 elog_buf = kmalloc(ELOG_ENTRY_LEN, GFP_KERNEL);
281 if (elog_buf == NULL)
282 goto err_release_elog;
283
284 mce_register_decode_chain(nb: &extlog_mce_dec);
285 /* enable OS to be involved to take over management from BIOS */
286 ((struct extlog_l1_head *)extlog_l1_addr)->flags |= FLAG_OS_OPTIN;
287
288 return 0;
289
290err_release_elog:
291 if (elog_addr)
292 acpi_os_unmap_iomem(virt: elog_addr, size: elog_size);
293 release_mem_region(elog_base, elog_size);
294err_release_l1_dir:
295 if (extlog_l1_addr)
296 acpi_os_unmap_iomem(virt: extlog_l1_addr, size: l1_size);
297 release_mem_region(l1_dirbase, l1_size);
298err:
299 pr_warn(FW_BUG "Extended error log disabled because of problems parsing f/w tables\n");
300 return rc;
301}
302
303static void __exit extlog_exit(void)
304{
305 mce_unregister_decode_chain(nb: &extlog_mce_dec);
306 ((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN;
307 if (extlog_l1_addr)
308 acpi_os_unmap_iomem(virt: extlog_l1_addr, size: l1_size);
309 if (elog_addr)
310 acpi_os_unmap_iomem(virt: elog_addr, size: elog_size);
311 release_mem_region(elog_base, elog_size);
312 release_mem_region(l1_dirbase, l1_size);
313 kfree(objp: elog_buf);
314}
315
316module_init(extlog_init);
317module_exit(extlog_exit);
318
319MODULE_AUTHOR("Chen, Gong <gong.chen@intel.com>");
320MODULE_DESCRIPTION("Extended MCA Error Log Driver");
321MODULE_LICENSE("GPL");
322

source code of linux/drivers/acpi/acpi_extlog.c