xref: /openbmc/linux/drivers/acpi/acpi_fpdt.c (revision e5f516b2)
1 // SPDX-License-Identifier: GPL-2.0-only
2 
3 /*
4  * FPDT support for exporting boot and suspend/resume performance data
5  *
6  * Copyright (C) 2021 Intel Corporation. All rights reserved.
7  */
8 
9 #define pr_fmt(fmt) "ACPI FPDT: " fmt
10 
11 #include <linux/acpi.h>
12 
13 /*
14  * FPDT contains ACPI table header and a number of fpdt_subtable_entries.
15  * Each fpdt_subtable_entry points to a subtable: FBPT or S3PT.
16  * Each FPDT subtable (FBPT/S3PT) is composed of a fpdt_subtable_header
17  * and a number of fpdt performance records.
18  * Each FPDT performance record is composed of a fpdt_record_header and
19  * performance data fields, for boot or suspend or resume phase.
20  */
21 enum fpdt_subtable_type {
22 	SUBTABLE_FBPT,
23 	SUBTABLE_S3PT,
24 };
25 
26 struct fpdt_subtable_entry {
27 	u16 type;		/* refer to enum fpdt_subtable_type */
28 	u8 length;
29 	u8 revision;
30 	u32 reserved;
31 	u64 address;		/* physical address of the S3PT/FBPT table */
32 };
33 
34 struct fpdt_subtable_header {
35 	u32 signature;
36 	u32 length;
37 };
38 
39 enum fpdt_record_type {
40 	RECORD_S3_RESUME,
41 	RECORD_S3_SUSPEND,
42 	RECORD_BOOT,
43 };
44 
45 struct fpdt_record_header {
46 	u16 type;		/* refer to enum fpdt_record_type */
47 	u8 length;
48 	u8 revision;
49 };
50 
51 struct resume_performance_record {
52 	struct fpdt_record_header header;
53 	u32 resume_count;
54 	u64 resume_prev;
55 	u64 resume_avg;
56 } __attribute__((packed));
57 
58 struct boot_performance_record {
59 	struct fpdt_record_header header;
60 	u32 reserved;
61 	u64 firmware_start;
62 	u64 bootloader_load;
63 	u64 bootloader_launch;
64 	u64 exitbootservice_start;
65 	u64 exitbootservice_end;
66 } __attribute__((packed));
67 
68 struct suspend_performance_record {
69 	struct fpdt_record_header header;
70 	u64 suspend_start;
71 	u64 suspend_end;
72 } __attribute__((packed));
73 
74 
75 static struct resume_performance_record *record_resume;
76 static struct suspend_performance_record *record_suspend;
77 static struct boot_performance_record *record_boot;
78 
79 #define FPDT_ATTR(phase, name)	\
80 static ssize_t name##_show(struct kobject *kobj,	\
81 		 struct kobj_attribute *attr, char *buf)	\
82 {	\
83 	return sprintf(buf, "%llu\n", record_##phase->name);	\
84 }	\
85 static struct kobj_attribute name##_attr =	\
86 __ATTR(name##_ns, 0444, name##_show, NULL)
87 
88 FPDT_ATTR(resume, resume_prev);
89 FPDT_ATTR(resume, resume_avg);
90 FPDT_ATTR(suspend, suspend_start);
91 FPDT_ATTR(suspend, suspend_end);
92 FPDT_ATTR(boot, firmware_start);
93 FPDT_ATTR(boot, bootloader_load);
94 FPDT_ATTR(boot, bootloader_launch);
95 FPDT_ATTR(boot, exitbootservice_start);
96 FPDT_ATTR(boot, exitbootservice_end);
97 
resume_count_show(struct kobject * kobj,struct kobj_attribute * attr,char * buf)98 static ssize_t resume_count_show(struct kobject *kobj,
99 				 struct kobj_attribute *attr, char *buf)
100 {
101 	return sprintf(buf, "%u\n", record_resume->resume_count);
102 }
103 
104 static struct kobj_attribute resume_count_attr =
105 __ATTR_RO(resume_count);
106 
107 static struct attribute *resume_attrs[] = {
108 	&resume_count_attr.attr,
109 	&resume_prev_attr.attr,
110 	&resume_avg_attr.attr,
111 	NULL
112 };
113 
114 static const struct attribute_group resume_attr_group = {
115 	.attrs = resume_attrs,
116 	.name = "resume",
117 };
118 
119 static struct attribute *suspend_attrs[] = {
120 	&suspend_start_attr.attr,
121 	&suspend_end_attr.attr,
122 	NULL
123 };
124 
125 static const struct attribute_group suspend_attr_group = {
126 	.attrs = suspend_attrs,
127 	.name = "suspend",
128 };
129 
130 static struct attribute *boot_attrs[] = {
131 	&firmware_start_attr.attr,
132 	&bootloader_load_attr.attr,
133 	&bootloader_launch_attr.attr,
134 	&exitbootservice_start_attr.attr,
135 	&exitbootservice_end_attr.attr,
136 	NULL
137 };
138 
139 static const struct attribute_group boot_attr_group = {
140 	.attrs = boot_attrs,
141 	.name = "boot",
142 };
143 
144 static struct kobject *fpdt_kobj;
145 
146 #if defined CONFIG_X86 && defined CONFIG_PHYS_ADDR_T_64BIT
147 #include <linux/processor.h>
fpdt_address_valid(u64 address)148 static bool fpdt_address_valid(u64 address)
149 {
150 	/*
151 	 * On some systems the table contains invalid addresses
152 	 * with unsuppored high address bits set, check for this.
153 	 */
154 	return !(address >> boot_cpu_data.x86_phys_bits);
155 }
156 #else
fpdt_address_valid(u64 address)157 static bool fpdt_address_valid(u64 address)
158 {
159 	return true;
160 }
161 #endif
162 
fpdt_process_subtable(u64 address,u32 subtable_type)163 static int fpdt_process_subtable(u64 address, u32 subtable_type)
164 {
165 	struct fpdt_subtable_header *subtable_header;
166 	struct fpdt_record_header *record_header;
167 	char *signature = (subtable_type == SUBTABLE_FBPT ? "FBPT" : "S3PT");
168 	u32 length, offset;
169 	int result;
170 
171 	if (!fpdt_address_valid(address)) {
172 		pr_info(FW_BUG "invalid physical address: 0x%llx!\n", address);
173 		return -EINVAL;
174 	}
175 
176 	subtable_header = acpi_os_map_memory(address, sizeof(*subtable_header));
177 	if (!subtable_header)
178 		return -ENOMEM;
179 
180 	if (strncmp((char *)&subtable_header->signature, signature, 4)) {
181 		pr_info(FW_BUG "subtable signature and type mismatch!\n");
182 		return -EINVAL;
183 	}
184 
185 	length = subtable_header->length;
186 	acpi_os_unmap_memory(subtable_header, sizeof(*subtable_header));
187 
188 	subtable_header = acpi_os_map_memory(address, length);
189 	if (!subtable_header)
190 		return -ENOMEM;
191 
192 	offset = sizeof(*subtable_header);
193 	while (offset < length) {
194 		record_header = (void *)subtable_header + offset;
195 		offset += record_header->length;
196 
197 		if (!record_header->length) {
198 			pr_err(FW_BUG "Zero-length record found in FPTD.\n");
199 			result = -EINVAL;
200 			goto err;
201 		}
202 
203 		switch (record_header->type) {
204 		case RECORD_S3_RESUME:
205 			if (subtable_type != SUBTABLE_S3PT) {
206 				pr_err(FW_BUG "Invalid record %d for subtable %s\n",
207 				     record_header->type, signature);
208 				result = -EINVAL;
209 				goto err;
210 			}
211 			if (record_resume) {
212 				pr_err("Duplicate resume performance record found.\n");
213 				continue;
214 			}
215 			record_resume = (struct resume_performance_record *)record_header;
216 			result = sysfs_create_group(fpdt_kobj, &resume_attr_group);
217 			if (result)
218 				goto err;
219 			break;
220 		case RECORD_S3_SUSPEND:
221 			if (subtable_type != SUBTABLE_S3PT) {
222 				pr_err(FW_BUG "Invalid %d for subtable %s\n",
223 				     record_header->type, signature);
224 				continue;
225 			}
226 			if (record_suspend) {
227 				pr_err("Duplicate suspend performance record found.\n");
228 				continue;
229 			}
230 			record_suspend = (struct suspend_performance_record *)record_header;
231 			result = sysfs_create_group(fpdt_kobj, &suspend_attr_group);
232 			if (result)
233 				goto err;
234 			break;
235 		case RECORD_BOOT:
236 			if (subtable_type != SUBTABLE_FBPT) {
237 				pr_err(FW_BUG "Invalid %d for subtable %s\n",
238 				     record_header->type, signature);
239 				result = -EINVAL;
240 				goto err;
241 			}
242 			if (record_boot) {
243 				pr_err("Duplicate boot performance record found.\n");
244 				continue;
245 			}
246 			record_boot = (struct boot_performance_record *)record_header;
247 			result = sysfs_create_group(fpdt_kobj, &boot_attr_group);
248 			if (result)
249 				goto err;
250 			break;
251 
252 		default:
253 			/* Other types are reserved in ACPI 6.4 spec. */
254 			break;
255 		}
256 	}
257 	return 0;
258 
259 err:
260 	if (record_boot)
261 		sysfs_remove_group(fpdt_kobj, &boot_attr_group);
262 
263 	if (record_suspend)
264 		sysfs_remove_group(fpdt_kobj, &suspend_attr_group);
265 
266 	if (record_resume)
267 		sysfs_remove_group(fpdt_kobj, &resume_attr_group);
268 
269 	return result;
270 }
271 
acpi_init_fpdt(void)272 static int __init acpi_init_fpdt(void)
273 {
274 	acpi_status status;
275 	struct acpi_table_header *header;
276 	struct fpdt_subtable_entry *subtable;
277 	u32 offset = sizeof(*header);
278 	int result;
279 
280 	status = acpi_get_table(ACPI_SIG_FPDT, 0, &header);
281 
282 	if (ACPI_FAILURE(status))
283 		return 0;
284 
285 	fpdt_kobj = kobject_create_and_add("fpdt", acpi_kobj);
286 	if (!fpdt_kobj) {
287 		result = -ENOMEM;
288 		goto err_nomem;
289 	}
290 
291 	while (offset < header->length) {
292 		subtable = (void *)header + offset;
293 		switch (subtable->type) {
294 		case SUBTABLE_FBPT:
295 		case SUBTABLE_S3PT:
296 			result = fpdt_process_subtable(subtable->address,
297 					      subtable->type);
298 			if (result)
299 				goto err_subtable;
300 			break;
301 		default:
302 			/* Other types are reserved in ACPI 6.4 spec. */
303 			break;
304 		}
305 		offset += sizeof(*subtable);
306 	}
307 	return 0;
308 err_subtable:
309 	kobject_put(fpdt_kobj);
310 
311 err_nomem:
312 	acpi_put_table(header);
313 	return result;
314 }
315 
316 fs_initcall(acpi_init_fpdt);
317