1/*
2 * Extended Error Log driver
3 *
4 * Copyright (C) 2013 Intel Corp.
5 * Author: Chen, Gong <gong.chen@intel.com>
6 *
7 * This file is licensed under GPLv2.
8 */
9
10#include <linux/module.h>
11#include <linux/acpi.h>
12#include <linux/cper.h>
13#include <linux/ratelimit.h>
14#include <linux/edac.h>
15#include <linux/ras.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 int old_edac_report_status;
47
48static u8 extlog_dsm_uuid[] __initdata = "663E35AF-CC10-41A4-88EA-5470AF055295";
49
50/* L1 table related physical address */
51static u64 elog_base;
52static size_t elog_size;
53static u64 l1_dirbase;
54static size_t l1_size;
55
56/* L1 table related virtual address */
57static void __iomem *extlog_l1_addr;
58static void __iomem *elog_addr;
59
60static void *elog_buf;
61
62static u64 *l1_entry_base;
63static u32 l1_percpu_entry;
64
65#define ELOG_IDX(cpu, bank) \
66	(cpu_physical_id(cpu) * l1_percpu_entry + (bank))
67
68#define ELOG_ENTRY_DATA(idx) \
69	(*(l1_entry_base + (idx)))
70
71#define ELOG_ENTRY_ADDR(phyaddr) \
72	(phyaddr - elog_base + (u8 *)elog_addr)
73
74static struct acpi_hest_generic_status *extlog_elog_entry_check(int cpu, int bank)
75{
76	int idx;
77	u64 data;
78	struct acpi_hest_generic_status *estatus;
79
80	WARN_ON(cpu < 0);
81	idx = ELOG_IDX(cpu, bank);
82	data = ELOG_ENTRY_DATA(idx);
83	if ((data & ELOG_ENTRY_VALID) == 0)
84		return NULL;
85
86	data &= EXT_ELOG_ENTRY_MASK;
87	estatus = (struct acpi_hest_generic_status *)ELOG_ENTRY_ADDR(data);
88
89	/* if no valid data in elog entry, just return */
90	if (estatus->block_status == 0)
91		return NULL;
92
93	return estatus;
94}
95
96static void __print_extlog_rcd(const char *pfx,
97			       struct acpi_hest_generic_status *estatus, int cpu)
98{
99	static atomic_t seqno;
100	unsigned int curr_seqno;
101	char pfx_seq[64];
102
103	if (!pfx) {
104		if (estatus->error_severity <= CPER_SEV_CORRECTED)
105			pfx = KERN_INFO;
106		else
107			pfx = KERN_ERR;
108	}
109	curr_seqno = atomic_inc_return(&seqno);
110	snprintf(pfx_seq, sizeof(pfx_seq), "%s{%u}", pfx, curr_seqno);
111	printk("%s""Hardware error detected on CPU%d\n", pfx_seq, cpu);
112	cper_estatus_print(pfx_seq, estatus);
113}
114
115static int print_extlog_rcd(const char *pfx,
116			    struct acpi_hest_generic_status *estatus, int cpu)
117{
118	/* Not more than 2 messages every 5 seconds */
119	static DEFINE_RATELIMIT_STATE(ratelimit_corrected, 5*HZ, 2);
120	static DEFINE_RATELIMIT_STATE(ratelimit_uncorrected, 5*HZ, 2);
121	struct ratelimit_state *ratelimit;
122
123	if (estatus->error_severity == CPER_SEV_CORRECTED ||
124	    (estatus->error_severity == CPER_SEV_INFORMATIONAL))
125		ratelimit = &ratelimit_corrected;
126	else
127		ratelimit = &ratelimit_uncorrected;
128	if (__ratelimit(ratelimit)) {
129		__print_extlog_rcd(pfx, estatus, cpu);
130		return 0;
131	}
132
133	return 1;
134}
135
136static int extlog_print(struct notifier_block *nb, unsigned long val,
137			void *data)
138{
139	struct mce *mce = (struct mce *)data;
140	int	bank = mce->bank;
141	int	cpu = mce->extcpu;
142	struct acpi_hest_generic_status *estatus, *tmp;
143	struct acpi_hest_generic_data *gdata;
144	const uuid_le *fru_id = &NULL_UUID_LE;
145	char *fru_text = "";
146	uuid_le *sec_type;
147	static u32 err_seq;
148
149	estatus = extlog_elog_entry_check(cpu, bank);
150	if (estatus == NULL)
151		return NOTIFY_DONE;
152
153	memcpy(elog_buf, (void *)estatus, ELOG_ENTRY_LEN);
154	/* clear record status to enable BIOS to update it again */
155	estatus->block_status = 0;
156
157	tmp = (struct acpi_hest_generic_status *)elog_buf;
158
159	if (!ras_userspace_consumers()) {
160		print_extlog_rcd(NULL, tmp, cpu);
161		goto out;
162	}
163
164	/* log event via trace */
165	err_seq++;
166	gdata = (struct acpi_hest_generic_data *)(tmp + 1);
167	if (gdata->validation_bits & CPER_SEC_VALID_FRU_ID)
168		fru_id = (uuid_le *)gdata->fru_id;
169	if (gdata->validation_bits & CPER_SEC_VALID_FRU_TEXT)
170		fru_text = gdata->fru_text;
171	sec_type = (uuid_le *)gdata->section_type;
172	if (!uuid_le_cmp(*sec_type, CPER_SEC_PLATFORM_MEM)) {
173		struct cper_sec_mem_err *mem = (void *)(gdata + 1);
174		if (gdata->error_data_length >= sizeof(*mem))
175			trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
176					       (u8)gdata->error_severity);
177	}
178
179out:
180	return NOTIFY_STOP;
181}
182
183static bool __init extlog_get_l1addr(void)
184{
185	u8 uuid[16];
186	acpi_handle handle;
187	union acpi_object *obj;
188
189	acpi_str_to_uuid(extlog_dsm_uuid, uuid);
190
191	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
192		return false;
193	if (!acpi_check_dsm(handle, uuid, EXTLOG_DSM_REV, 1 << EXTLOG_FN_ADDR))
194		return false;
195	obj = acpi_evaluate_dsm_typed(handle, uuid, EXTLOG_DSM_REV,
196				      EXTLOG_FN_ADDR, NULL, ACPI_TYPE_INTEGER);
197	if (!obj) {
198		return false;
199	} else {
200		l1_dirbase = obj->integer.value;
201		ACPI_FREE(obj);
202	}
203
204	/* Spec says L1 directory must be 4K aligned, bail out if it isn't */
205	if (l1_dirbase & ((1 << 12) - 1)) {
206		pr_warn(FW_BUG "L1 Directory is invalid at physical %llx\n",
207			l1_dirbase);
208		return false;
209	}
210
211	return true;
212}
213static struct notifier_block extlog_mce_dec = {
214	.notifier_call	= extlog_print,
215};
216
217static int __init extlog_init(void)
218{
219	struct extlog_l1_head *l1_head;
220	void __iomem *extlog_l1_hdr;
221	size_t l1_hdr_size;
222	struct resource *r;
223	u64 cap;
224	int rc;
225
226	rdmsrl(MSR_IA32_MCG_CAP, cap);
227
228	if (!(cap & MCG_ELOG_P) || !extlog_get_l1addr())
229		return -ENODEV;
230
231	if (get_edac_report_status() == EDAC_REPORTING_FORCE) {
232		pr_warn("Not loading eMCA, error reporting force-enabled through EDAC.\n");
233		return -EPERM;
234	}
235
236	rc = -EINVAL;
237	/* get L1 header to fetch necessary information */
238	l1_hdr_size = sizeof(struct extlog_l1_head);
239	r = request_mem_region(l1_dirbase, l1_hdr_size, "L1 DIR HDR");
240	if (!r) {
241		pr_warn(FW_BUG EMCA_BUG,
242			(unsigned long long)l1_dirbase,
243			(unsigned long long)l1_dirbase + l1_hdr_size);
244		goto err;
245	}
246
247	extlog_l1_hdr = acpi_os_map_iomem(l1_dirbase, l1_hdr_size);
248	l1_head = (struct extlog_l1_head *)extlog_l1_hdr;
249	l1_size = l1_head->total_len;
250	l1_percpu_entry = l1_head->entries;
251	elog_base = l1_head->elog_base;
252	elog_size = l1_head->elog_len;
253	acpi_os_unmap_iomem(extlog_l1_hdr, l1_hdr_size);
254	release_mem_region(l1_dirbase, l1_hdr_size);
255
256	/* remap L1 header again based on completed information */
257	r = request_mem_region(l1_dirbase, l1_size, "L1 Table");
258	if (!r) {
259		pr_warn(FW_BUG EMCA_BUG,
260			(unsigned long long)l1_dirbase,
261			(unsigned long long)l1_dirbase + l1_size);
262		goto err;
263	}
264	extlog_l1_addr = acpi_os_map_iomem(l1_dirbase, l1_size);
265	l1_entry_base = (u64 *)((u8 *)extlog_l1_addr + l1_hdr_size);
266
267	/* remap elog table */
268	r = request_mem_region(elog_base, elog_size, "Elog Table");
269	if (!r) {
270		pr_warn(FW_BUG EMCA_BUG,
271			(unsigned long long)elog_base,
272			(unsigned long long)elog_base + elog_size);
273		goto err_release_l1_dir;
274	}
275	elog_addr = acpi_os_map_iomem(elog_base, elog_size);
276
277	rc = -ENOMEM;
278	/* allocate buffer to save elog record */
279	elog_buf = kmalloc(ELOG_ENTRY_LEN, GFP_KERNEL);
280	if (elog_buf == NULL)
281		goto err_release_elog;
282
283	/*
284	 * eMCA event report method has higher priority than EDAC method,
285	 * unless EDAC event report method is mandatory.
286	 */
287	old_edac_report_status = get_edac_report_status();
288	set_edac_report_status(EDAC_REPORTING_DISABLED);
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	set_edac_report_status(old_edac_report_status);
311	mce_unregister_decode_chain(&extlog_mce_dec);
312	((struct extlog_l1_head *)extlog_l1_addr)->flags &= ~FLAG_OS_OPTIN;
313	if (extlog_l1_addr)
314		acpi_os_unmap_iomem(extlog_l1_addr, l1_size);
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