1 /*
2  * APEI Hardware Error Souce Table support
3  *
4  * HEST describes error sources in detail; communicates operational
5  * parameters (i.e. severity levels, masking bits, and threshold
6  * values) to Linux as necessary. It also allows the BIOS to report
7  * non-standard error sources to Linux (for example, chipset-specific
8  * error registers).
9  *
10  * For more information about HEST, please refer to ACPI Specification
11  * version 4.0, section 17.3.2.
12  *
13  * Copyright 2009 Intel Corp.
14  *   Author: Huang Ying <ying.huang@intel.com>
15  *
16  * This program is free software; you can redistribute it and/or
17  * modify it under the terms of the GNU General Public License version
18  * 2 as published by the Free Software Foundation;
19  *
20  * This program is distributed in the hope that it will be useful,
21  * but WITHOUT ANY WARRANTY; without even the implied warranty of
22  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
23  * GNU General Public License for more details.
24  *
25  * You should have received a copy of the GNU General Public License
26  * along with this program; If not, see <http://www.gnu.org/licenses/>.
27  */
28 
29 #include <xen/errno.h>
30 #include <xen/init.h>
31 #include <xen/kernel.h>
32 #include <xen/mm.h>
33 #include <xen/pfn.h>
34 #include <acpi/acpi.h>
35 #include <acpi/apei.h>
36 
37 #include "apei-internal.h"
38 
39 #define HEST_PFX "HEST: "
40 
41 static bool_t hest_disable;
42 boolean_param("hest_disable", hest_disable);
43 
44 /* HEST table parsing */
45 
46 static struct acpi_table_hest *__read_mostly hest_tab;
47 
48 static const int hest_esrc_len_tab[ACPI_HEST_TYPE_RESERVED] = {
49 	[ACPI_HEST_TYPE_IA32_CHECK] = -1,	/* need further calculation */
50 	[ACPI_HEST_TYPE_IA32_CORRECTED_CHECK] = -1,
51 	[ACPI_HEST_TYPE_IA32_NMI] = sizeof(struct acpi_hest_ia_nmi),
52 	[ACPI_HEST_TYPE_AER_ROOT_PORT] = sizeof(struct acpi_hest_aer_root),
53 	[ACPI_HEST_TYPE_AER_ENDPOINT] = sizeof(struct acpi_hest_aer),
54 	[ACPI_HEST_TYPE_AER_BRIDGE] = sizeof(struct acpi_hest_aer_bridge),
55 	[ACPI_HEST_TYPE_GENERIC_ERROR] = sizeof(struct acpi_hest_generic),
56 };
57 
hest_esrc_len(const struct acpi_hest_header * hest_hdr)58 static int hest_esrc_len(const struct acpi_hest_header *hest_hdr)
59 {
60 	u16 hest_type = hest_hdr->type;
61 	int len;
62 
63 	if (hest_type >= ACPI_HEST_TYPE_RESERVED)
64 		return 0;
65 
66 	len = hest_esrc_len_tab[hest_type];
67 
68 	if (hest_type == ACPI_HEST_TYPE_IA32_CORRECTED_CHECK) {
69 		const struct acpi_hest_ia_corrected *cmc =
70 			container_of(hest_hdr,
71 				     const struct acpi_hest_ia_corrected,
72 				     header);
73 
74 		len = sizeof(*cmc) + cmc->num_hardware_banks *
75 		      sizeof(struct acpi_hest_ia_error_bank);
76 	} else if (hest_type == ACPI_HEST_TYPE_IA32_CHECK) {
77 		const struct acpi_hest_ia_machine_check *mc =
78 			container_of(hest_hdr,
79 				     const struct acpi_hest_ia_machine_check,
80 				     header);
81 
82 		len = sizeof(*mc) + mc->num_hardware_banks *
83 		      sizeof(struct acpi_hest_ia_error_bank);
84 	}
85 	BUG_ON(len == -1);
86 
87 	return len;
88 };
89 
apei_hest_parse(apei_hest_func_t func,void * data)90 int apei_hest_parse(apei_hest_func_t func, void *data)
91 {
92 	struct acpi_hest_header *hest_hdr;
93 	int i, rc, len;
94 
95 	if (hest_disable || !hest_tab)
96 		return -EINVAL;
97 
98 	hest_hdr = (struct acpi_hest_header *)(hest_tab + 1);
99 	for (i = 0; i < hest_tab->error_source_count; i++) {
100 		len = hest_esrc_len(hest_hdr);
101 		if (!len) {
102 			printk(XENLOG_WARNING HEST_PFX
103 			       "Unknown or unused hardware error source "
104 			       "type: %d for hardware error source: %d\n",
105 			       hest_hdr->type, hest_hdr->source_id);
106 			return -EINVAL;
107 		}
108 		if ((void *)hest_hdr + len >
109 		    (void *)hest_tab + hest_tab->header.length) {
110 			printk(XENLOG_WARNING HEST_PFX
111 			       "Table contents overflow for hardware error source: %d\n",
112 			       hest_hdr->source_id);
113 			return -EINVAL;
114 		}
115 
116 		rc = func(hest_hdr, data);
117 		if (rc)
118 			return rc;
119 
120 		hest_hdr = (void *)hest_hdr + len;
121 	}
122 
123 	return 0;
124 }
125 
126 /*
127  * Check if firmware advertises firmware first mode. We need FF bit to be set
128  * along with a set of MC banks which work in FF mode.
129  */
hest_parse_cmc(const struct acpi_hest_header * hest_hdr,void * data)130 static int __init hest_parse_cmc(const struct acpi_hest_header *hest_hdr,
131 				 void *data)
132 {
133 #ifdef CONFIG_X86_MCE
134 	unsigned int i;
135 	const struct acpi_hest_ia_corrected *cmc;
136 	const struct acpi_hest_ia_error_bank *mc_bank;
137 
138 	if (hest_hdr->type != ACPI_HEST_TYPE_IA32_CORRECTED_CHECK)
139 		return 0;
140 
141 	cmc = container_of(hest_hdr, const struct acpi_hest_ia_corrected, header);
142 	if (!cmc->enabled)
143 		return 0;
144 
145 	/*
146 	 * We expect HEST to provide a list of MC banks that report errors
147 	 * in firmware first mode. Otherwise, return non-zero value to
148 	 * indicate that we are done parsing HEST.
149 	 */
150 	if (!(cmc->flags & ACPI_HEST_FIRMWARE_FIRST) || !cmc->num_hardware_banks)
151 		return 1;
152 
153 	printk(XENLOG_INFO HEST_PFX "Enabling Firmware First mode for corrected errors.\n");
154 
155 	mc_bank = (const struct acpi_hest_ia_error_bank *)(cmc + 1);
156 	for (i = 0; i < cmc->num_hardware_banks; i++, mc_bank++)
157 		mce_disable_bank(mc_bank->bank_number);
158 #else
159 # define acpi_disable_cmcff 1
160 #endif
161 
162 	return 1;
163 }
164 
acpi_hest_init(void)165 void __init acpi_hest_init(void)
166 {
167 	acpi_status status;
168 	acpi_physical_address hest_addr;
169 	acpi_native_uint hest_len;
170 
171 	if (acpi_disabled)
172 		return;
173 
174 	if (hest_disable) {
175 		printk(XENLOG_INFO HEST_PFX "Table parsing disabled.\n");
176 		return;
177 	}
178 
179 	status = acpi_get_table_phys(ACPI_SIG_HEST, 0, &hest_addr, &hest_len);
180 	if (status == AE_NOT_FOUND)
181 		goto err;
182 	if (ACPI_FAILURE(status)) {
183 		printk(XENLOG_ERR HEST_PFX "Failed to get table, %s\n",
184 		       acpi_format_exception(status));
185 		goto err;
186 	}
187 	map_pages_to_xen((unsigned long)__va(hest_addr), PFN_DOWN(hest_addr),
188 			 PFN_UP(hest_addr + hest_len) - PFN_DOWN(hest_addr),
189 			 PAGE_HYPERVISOR);
190 	hest_tab = __va(hest_addr);
191 
192 	if (!acpi_disable_cmcff)
193 		apei_hest_parse(hest_parse_cmc, NULL);
194 
195 	printk(XENLOG_INFO HEST_PFX "Table parsing has been initialized\n");
196 	return;
197 err:
198 	hest_disable = 1;
199 }
200