1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * PowerNV OPAL Dump Interface
4  *
5  * Copyright 2013,2014 IBM Corp.
6  */
7 
8 #include <linux/kobject.h>
9 #include <linux/mm.h>
10 #include <linux/slab.h>
11 #include <linux/vmalloc.h>
12 #include <linux/pagemap.h>
13 #include <linux/delay.h>
14 #include <linux/interrupt.h>
15 
16 #include <asm/opal.h>
17 
18 #define DUMP_TYPE_FSP	0x01
19 
20 struct dump_obj {
21 	struct kobject  kobj;
22 	struct bin_attribute dump_attr;
23 	uint32_t	id;  /* becomes object name */
24 	uint32_t	type;
25 	uint32_t	size;
26 	char		*buffer;
27 };
28 #define to_dump_obj(x) container_of(x, struct dump_obj, kobj)
29 
30 struct dump_attribute {
31 	struct attribute attr;
32 	ssize_t (*show)(struct dump_obj *dump, struct dump_attribute *attr,
33 			char *buf);
34 	ssize_t (*store)(struct dump_obj *dump, struct dump_attribute *attr,
35 			 const char *buf, size_t count);
36 };
37 #define to_dump_attr(x) container_of(x, struct dump_attribute, attr)
38 
39 static ssize_t dump_id_show(struct dump_obj *dump_obj,
40 			    struct dump_attribute *attr,
41 			    char *buf)
42 {
43 	return sprintf(buf, "0x%x\n", dump_obj->id);
44 }
45 
46 static const char* dump_type_to_string(uint32_t type)
47 {
48 	switch (type) {
49 	case 0x01: return "SP Dump";
50 	case 0x02: return "System/Platform Dump";
51 	case 0x03: return "SMA Dump";
52 	default: return "unknown";
53 	}
54 }
55 
56 static ssize_t dump_type_show(struct dump_obj *dump_obj,
57 			      struct dump_attribute *attr,
58 			      char *buf)
59 {
60 
61 	return sprintf(buf, "0x%x %s\n", dump_obj->type,
62 		       dump_type_to_string(dump_obj->type));
63 }
64 
65 static ssize_t dump_ack_show(struct dump_obj *dump_obj,
66 			     struct dump_attribute *attr,
67 			     char *buf)
68 {
69 	return sprintf(buf, "ack - acknowledge dump\n");
70 }
71 
72 /*
73  * Send acknowledgement to OPAL
74  */
75 static int64_t dump_send_ack(uint32_t dump_id)
76 {
77 	int rc;
78 
79 	rc = opal_dump_ack(dump_id);
80 	if (rc)
81 		pr_warn("%s: Failed to send ack to Dump ID 0x%x (%d)\n",
82 			__func__, dump_id, rc);
83 	return rc;
84 }
85 
86 static ssize_t dump_ack_store(struct dump_obj *dump_obj,
87 			      struct dump_attribute *attr,
88 			      const char *buf,
89 			      size_t count)
90 {
91 	dump_send_ack(dump_obj->id);
92 	sysfs_remove_file_self(&dump_obj->kobj, &attr->attr);
93 	kobject_put(&dump_obj->kobj);
94 	return count;
95 }
96 
97 /* Attributes of a dump
98  * The binary attribute of the dump itself is dynamic
99  * due to the dynamic size of the dump
100  */
101 static struct dump_attribute id_attribute =
102 	__ATTR(id, 0444, dump_id_show, NULL);
103 static struct dump_attribute type_attribute =
104 	__ATTR(type, 0444, dump_type_show, NULL);
105 static struct dump_attribute ack_attribute =
106 	__ATTR(acknowledge, 0660, dump_ack_show, dump_ack_store);
107 
108 static ssize_t init_dump_show(struct dump_obj *dump_obj,
109 			      struct dump_attribute *attr,
110 			      char *buf)
111 {
112 	return sprintf(buf, "1 - initiate Service Processor(FSP) dump\n");
113 }
114 
115 static int64_t dump_fips_init(uint8_t type)
116 {
117 	int rc;
118 
119 	rc = opal_dump_init(type);
120 	if (rc)
121 		pr_warn("%s: Failed to initiate FSP dump (%d)\n",
122 			__func__, rc);
123 	return rc;
124 }
125 
126 static ssize_t init_dump_store(struct dump_obj *dump_obj,
127 			       struct dump_attribute *attr,
128 			       const char *buf,
129 			       size_t count)
130 {
131 	int rc;
132 
133 	rc = dump_fips_init(DUMP_TYPE_FSP);
134 	if (rc == OPAL_SUCCESS)
135 		pr_info("%s: Initiated FSP dump\n", __func__);
136 
137 	return count;
138 }
139 
140 static struct dump_attribute initiate_attribute =
141 	__ATTR(initiate_dump, 0600, init_dump_show, init_dump_store);
142 
143 static struct attribute *initiate_attrs[] = {
144 	&initiate_attribute.attr,
145 	NULL,
146 };
147 
148 static struct attribute_group initiate_attr_group = {
149 	.attrs = initiate_attrs,
150 };
151 
152 static struct kset *dump_kset;
153 
154 static ssize_t dump_attr_show(struct kobject *kobj,
155 			      struct attribute *attr,
156 			      char *buf)
157 {
158 	struct dump_attribute *attribute;
159 	struct dump_obj *dump;
160 
161 	attribute = to_dump_attr(attr);
162 	dump = to_dump_obj(kobj);
163 
164 	if (!attribute->show)
165 		return -EIO;
166 
167 	return attribute->show(dump, attribute, buf);
168 }
169 
170 static ssize_t dump_attr_store(struct kobject *kobj,
171 			       struct attribute *attr,
172 			       const char *buf, size_t len)
173 {
174 	struct dump_attribute *attribute;
175 	struct dump_obj *dump;
176 
177 	attribute = to_dump_attr(attr);
178 	dump = to_dump_obj(kobj);
179 
180 	if (!attribute->store)
181 		return -EIO;
182 
183 	return attribute->store(dump, attribute, buf, len);
184 }
185 
186 static const struct sysfs_ops dump_sysfs_ops = {
187 	.show = dump_attr_show,
188 	.store = dump_attr_store,
189 };
190 
191 static void dump_release(struct kobject *kobj)
192 {
193 	struct dump_obj *dump;
194 
195 	dump = to_dump_obj(kobj);
196 	vfree(dump->buffer);
197 	kfree(dump);
198 }
199 
200 static struct attribute *dump_default_attrs[] = {
201 	&id_attribute.attr,
202 	&type_attribute.attr,
203 	&ack_attribute.attr,
204 	NULL,
205 };
206 
207 static struct kobj_type dump_ktype = {
208 	.sysfs_ops = &dump_sysfs_ops,
209 	.release = &dump_release,
210 	.default_attrs = dump_default_attrs,
211 };
212 
213 static int64_t dump_read_info(uint32_t *dump_id, uint32_t *dump_size, uint32_t *dump_type)
214 {
215 	__be32 id, size, type;
216 	int rc;
217 
218 	type = cpu_to_be32(0xffffffff);
219 
220 	rc = opal_dump_info2(&id, &size, &type);
221 	if (rc == OPAL_PARAMETER)
222 		rc = opal_dump_info(&id, &size);
223 
224 	if (rc) {
225 		pr_warn("%s: Failed to get dump info (%d)\n",
226 			__func__, rc);
227 		return rc;
228 	}
229 
230 	*dump_id = be32_to_cpu(id);
231 	*dump_size = be32_to_cpu(size);
232 	*dump_type = be32_to_cpu(type);
233 
234 	return rc;
235 }
236 
237 static int64_t dump_read_data(struct dump_obj *dump)
238 {
239 	struct opal_sg_list *list;
240 	uint64_t addr;
241 	int64_t rc;
242 
243 	/* Allocate memory */
244 	dump->buffer = vzalloc(PAGE_ALIGN(dump->size));
245 	if (!dump->buffer) {
246 		pr_err("%s : Failed to allocate memory\n", __func__);
247 		rc = -ENOMEM;
248 		goto out;
249 	}
250 
251 	/* Generate SG list */
252 	list = opal_vmalloc_to_sg_list(dump->buffer, dump->size);
253 	if (!list) {
254 		rc = -ENOMEM;
255 		goto out;
256 	}
257 
258 	/* First entry address */
259 	addr = __pa(list);
260 
261 	/* Fetch data */
262 	rc = OPAL_BUSY_EVENT;
263 	while (rc == OPAL_BUSY || rc == OPAL_BUSY_EVENT) {
264 		rc = opal_dump_read(dump->id, addr);
265 		if (rc == OPAL_BUSY_EVENT) {
266 			opal_poll_events(NULL);
267 			msleep(20);
268 		}
269 	}
270 
271 	if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL)
272 		pr_warn("%s: Extract dump failed for ID 0x%x\n",
273 			__func__, dump->id);
274 
275 	/* Free SG list */
276 	opal_free_sg_list(list);
277 
278 out:
279 	return rc;
280 }
281 
282 static ssize_t dump_attr_read(struct file *filep, struct kobject *kobj,
283 			      struct bin_attribute *bin_attr,
284 			      char *buffer, loff_t pos, size_t count)
285 {
286 	ssize_t rc;
287 
288 	struct dump_obj *dump = to_dump_obj(kobj);
289 
290 	if (!dump->buffer) {
291 		rc = dump_read_data(dump);
292 
293 		if (rc != OPAL_SUCCESS && rc != OPAL_PARTIAL) {
294 			vfree(dump->buffer);
295 			dump->buffer = NULL;
296 
297 			return -EIO;
298 		}
299 		if (rc == OPAL_PARTIAL) {
300 			/* On a partial read, we just return EIO
301 			 * and rely on userspace to ask us to try
302 			 * again.
303 			 */
304 			pr_info("%s: Platform dump partially read. ID = 0x%x\n",
305 				__func__, dump->id);
306 			return -EIO;
307 		}
308 	}
309 
310 	memcpy(buffer, dump->buffer + pos, count);
311 
312 	/* You may think we could free the dump buffer now and retrieve
313 	 * it again later if needed, but due to current firmware limitation,
314 	 * that's not the case. So, once read into userspace once,
315 	 * we keep the dump around until it's acknowledged by userspace.
316 	 */
317 
318 	return count;
319 }
320 
321 static struct dump_obj *create_dump_obj(uint32_t id, size_t size,
322 					uint32_t type)
323 {
324 	struct dump_obj *dump;
325 	int rc;
326 
327 	dump = kzalloc(sizeof(*dump), GFP_KERNEL);
328 	if (!dump)
329 		return NULL;
330 
331 	dump->kobj.kset = dump_kset;
332 
333 	kobject_init(&dump->kobj, &dump_ktype);
334 
335 	sysfs_bin_attr_init(&dump->dump_attr);
336 
337 	dump->dump_attr.attr.name = "dump";
338 	dump->dump_attr.attr.mode = 0400;
339 	dump->dump_attr.size = size;
340 	dump->dump_attr.read = dump_attr_read;
341 
342 	dump->id = id;
343 	dump->size = size;
344 	dump->type = type;
345 
346 	rc = kobject_add(&dump->kobj, NULL, "0x%x-0x%x", type, id);
347 	if (rc) {
348 		kobject_put(&dump->kobj);
349 		return NULL;
350 	}
351 
352 	rc = sysfs_create_bin_file(&dump->kobj, &dump->dump_attr);
353 	if (rc) {
354 		kobject_put(&dump->kobj);
355 		return NULL;
356 	}
357 
358 	pr_info("%s: New platform dump. ID = 0x%x Size %u\n",
359 		__func__, dump->id, dump->size);
360 
361 	kobject_uevent(&dump->kobj, KOBJ_ADD);
362 
363 	return dump;
364 }
365 
366 static irqreturn_t process_dump(int irq, void *data)
367 {
368 	int rc;
369 	uint32_t dump_id, dump_size, dump_type;
370 	char name[22];
371 	struct kobject *kobj;
372 
373 	rc = dump_read_info(&dump_id, &dump_size, &dump_type);
374 	if (rc != OPAL_SUCCESS)
375 		return IRQ_HANDLED;
376 
377 	sprintf(name, "0x%x-0x%x", dump_type, dump_id);
378 
379 	/* we may get notified twice, let's handle
380 	 * that gracefully and not create two conflicting
381 	 * entries.
382 	 */
383 	kobj = kset_find_obj(dump_kset, name);
384 	if (kobj) {
385 		/* Drop reference added by kset_find_obj() */
386 		kobject_put(kobj);
387 		return IRQ_HANDLED;
388 	}
389 
390 	create_dump_obj(dump_id, dump_size, dump_type);
391 
392 	return IRQ_HANDLED;
393 }
394 
395 void __init opal_platform_dump_init(void)
396 {
397 	int rc;
398 	int dump_irq;
399 
400 	/* ELOG not supported by firmware */
401 	if (!opal_check_token(OPAL_DUMP_READ))
402 		return;
403 
404 	dump_kset = kset_create_and_add("dump", NULL, opal_kobj);
405 	if (!dump_kset) {
406 		pr_warn("%s: Failed to create dump kset\n", __func__);
407 		return;
408 	}
409 
410 	rc = sysfs_create_group(&dump_kset->kobj, &initiate_attr_group);
411 	if (rc) {
412 		pr_warn("%s: Failed to create initiate dump attr group\n",
413 			__func__);
414 		kobject_put(&dump_kset->kobj);
415 		return;
416 	}
417 
418 	dump_irq = opal_event_request(ilog2(OPAL_EVENT_DUMP_AVAIL));
419 	if (!dump_irq) {
420 		pr_err("%s: Can't register OPAL event irq (%d)\n",
421 		       __func__, dump_irq);
422 		return;
423 	}
424 
425 	rc = request_threaded_irq(dump_irq, NULL, process_dump,
426 				IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
427 				"opal-dump", NULL);
428 	if (rc) {
429 		pr_err("%s: Can't request OPAL event irq (%d)\n",
430 		       __func__, rc);
431 		return;
432 	}
433 
434 	if (opal_check_token(OPAL_DUMP_RESEND))
435 		opal_dump_resend_notification();
436 }
437