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(&seqno);
108	snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}", pfx, curr_seqno);
109	printk("%s""Hardware error detected on CPU%d\n", pfx_seq, cpu);
110	cper_estatus_print(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)
149		return NOTIFY_DONE;
150
151	if (mce->kflags & MCE_HANDLED_CEC) {
152		estatus->block_status = 0;
153		return NOTIFY_DONE;
154	}
155
156	memcpy(elog_buf, (void *)estatus, ELOG_ENTRY_LEN);
157	/* clear record status to enable BIOS to update it again */
158	estatus->block_status = 0;
159
160	tmp = (struct acpi_hest_generic_status *)elog_buf;
161
162	if (!ras_userspace_consumers()) {
163		print_extlog_rcd(NULL, tmp, cpu);
164		goto out;
165	}
166
167	/* log event via trace */
168	err_seq++;
169	apei_estatus_for_each_section(tmp, gdata) {
170		if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
171			fru_id = (guid_t *)gdata->fru_id;
172		else
173			fru_id = &guid_null;
174		if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
175			fru_text = gdata->fru_text;
176		else
177			fru_text = "";
178		sec_type = (guid_t *)gdata->section_type;
179		if (guid_equal(sec_type, &CPER_SEC_PLATFORM_MEM)) {
180			struct cper_sec_mem_err *mem = acpi_hest_get_payload(gdata);
181
182			if (gdata->error_data_length >= sizeof(*mem))
183				trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
184						       (u8)gdata->error_severity);
185		}
186	}
187
188out:
189	mce->kflags |= MCE_HANDLED_EXTLOG;
190	return NOTIFY_OK;
191}
192
193static bool __init extlog_get_l1addr(void)
194{
195	guid_t guid;
196	acpi_handle handle;
197	union acpi_object *obj;
198
199	if (guid_parse(extlog_dsm_uuid, &guid))
200		return false;
201	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
202		return false;
203	if (!acpi_check_dsm(handle, &guid, EXTLOG_DSM_REV, 1 << EXTLOG_FN_ADDR))
204		return false;
205	obj = acpi_evaluate_dsm_typed(handle, &guid, EXTLOG_DSM_REV,
206				      EXTLOG_FN_ADDR, NULL, ACPI_TYPE_INTEGER);
207	if (!obj) {
208		return false;
209	} else {
210		l1_dirbase = obj->integer.value;
211		ACPI_FREE(obj);
212	}
213
214	/* Spec says L1 directory must be 4K aligned, bail out if it isn't */
215	if (l1_dirbase & ((1 << 12) - 1)) {
216		pr_warn(FW_BUG "L1 Directory is invalid at physical %llx\n",
217			l1_dirbase);
218		return false;
219	}
220
221	return true;
222}
223static struct notifier_block extlog_mce_dec = {
224	.notifier_call	= extlog_print,
225	.priority	= MCE_PRIO_EXTLOG,
226};
227
228static int __init extlog_init(void)
229{
230	struct extlog_l1_head *l1_head;
231	void __iomem *extlog_l1_hdr;
232	size_t l1_hdr_size;
233	struct resource *r;
234	u64 cap;
235	int rc;
236
237	if (rdmsrl_safe(MSR_IA32_MCG_CAP, &cap) ||
238	    !(cap & MCG_ELOG_P) ||
239	    !extlog_get_l1addr())
240		return -ENODEV;
241
242	rc = -EINVAL;
243	/* get L1 header to fetch necessary information */
244	l1_hdr_size = sizeof(struct extlog_l1_head);
245	r = request_mem_region(l1_dirbase, l1_hdr_size, "L1 DIR HDR");
246	if (!r) {
247		pr_warn(FW_BUG EMCA_BUG,
248			(unsigned long long)l1_dirbase,
249			(unsigned long long)l1_dirbase + l1_hdr_size);
250		goto err;
251	}
252
253	extlog_l1_hdr = acpi_os_map_iomem(l1_dirbase, l1_hdr_size);
254	l1_head = (struct extlog_l1_head *)extlog_l1_hdr;
255	l1_size = l1_head->total_len;
256	l1_percpu_entry = l1_head->entries;
257	elog_base = l1_head->elog_base;
258	elog_size = l1_head->elog_len;
259	acpi_os_unmap_iomem(extlog_l1_hdr, l1_hdr_size);
260	release_mem_region(l1_dirbase, l1_hdr_size);
261
262	/* remap L1 header again based on completed information */
263	r = request_mem_region(l1_dirbase, l1_size, "L1 Table");
264	if (!r) {
265		pr_warn(FW_BUG EMCA_BUG,
266			(unsigned long long)l1_dirbase,
267			(unsigned long long)l1_dirbase + l1_size);
268		goto err;
269	}
270	extlog_l1_addr = acpi_os_map_iomem(l1_dirbase, l1_size);
271	l1_entry_base = (u64 *)((u8 *)extlog_l1_addr + l1_hdr_size);
272
273	/* remap elog table */
274	r = request_mem_region(elog_base, elog_size, "Elog Table");
275	if (!r) {
276		pr_warn(FW_BUG EMCA_BUG,
277			(unsigned long long)elog_base,
278			(unsigned long long)elog_base + elog_size);
279		goto err_release_l1_dir;
280	}
281	elog_addr = acpi_os_map_iomem(elog_base, elog_size);
282
283	rc = -ENOMEM;
284	/* allocate buffer to save elog record */
285	elog_buf = kmalloc(ELOG_ENTRY_LEN, GFP_KERNEL);
286	if (elog_buf == NULL)
287		goto err_release_elog;
288
289	mce_register_decode_chain(&extlog_mce_dec);
290	/* enable OS to be involved to take over management from BIOS */
291	((struct extlog_l1_head *)extlog_l1_addr)->flags |= FLAG_OS_OPTIN;
292
293	return 0;
294
295err_release_elog:
296	if (elog_addr)
297		acpi_os_unmap_iomem(elog_addr, elog_size);
298	release_mem_region(elog_base, elog_size);
299err_release_l1_dir:
300	if (extlog_l1_addr)
301		acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
302	release_mem_region(l1_dirbase, l1_size);
303err:
304	pr_warn(FW_BUG "Extended error log disabled because of problems parsing f/w tables\n");
305	return rc;
306}
307
308static void __exit extlog_exit(void)
309{
310	mce_unregister_decode_chain(&extlog_mce_dec);
311	if (extlog_l1_addr) {
312		((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN;
313		acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
314	}
315	if (elog_addr)
316		acpi_os_unmap_iomem(elog_addr, elog_size);
317	release_mem_region(elog_base, elog_size);
318	release_mem_region(l1_dirbase, l1_size);
319	kfree(elog_buf);
320}
321
322module_init(extlog_init);
323module_exit(extlog_exit);
324
325MODULE_AUTHOR("Chen, Gong <gong.chen@intel.com>");
326MODULE_DESCRIPTION("Extended MCA Error Log Driver");
327MODULE_LICENSE("GPL");
328