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 == 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, 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(sec_type, &CPER_SEC_PLATFORM_MEM)) {
175			struct cper_sec_mem_err *mem = (void *)(gdata + 1);
176
177			if (gdata->error_data_length >= sizeof(*mem))
178				trace_extlog_mem_event(mem, err_seq, fru_id, fru_text,
179						       (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(extlog_dsm_uuid, &guid))
195		return false;
196	if (ACPI_FAILURE(acpi_get_handle(NULL, "\\_SB", &handle)))
197		return false;
198	if (!acpi_check_dsm(handle, &guid, EXTLOG_DSM_REV, 1 << EXTLOG_FN_ADDR))
199		return false;
200	obj = acpi_evaluate_dsm_typed(handle, &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, &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(l1_dirbase, 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(extlog_l1_hdr, 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(l1_dirbase, 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(elog_base, 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(&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(elog_addr, elog_size);
293	release_mem_region(elog_base, elog_size);
294err_release_l1_dir:
295	if (extlog_l1_addr)
296		acpi_os_unmap_iomem(extlog_l1_addr, 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(&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(extlog_l1_addr, l1_size);
309	if (elog_addr)
310		acpi_os_unmap_iomem(elog_addr, elog_size);
311	release_mem_region(elog_base, elog_size);
312	release_mem_region(l1_dirbase, l1_size);
313	kfree(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");