1 /* 2 * Error log support on PowerNV. 3 * 4 * Copyright 2013,2014 IBM Corp. 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 #include <linux/kernel.h> 12 #include <linux/init.h> 13 #include <linux/interrupt.h> 14 #include <linux/of.h> 15 #include <linux/slab.h> 16 #include <linux/sysfs.h> 17 #include <linux/fs.h> 18 #include <linux/vmalloc.h> 19 #include <linux/fcntl.h> 20 #include <linux/kobject.h> 21 #include <asm/uaccess.h> 22 #include <asm/opal.h> 23 24 struct elog_obj { 25 struct kobject kobj; 26 struct bin_attribute raw_attr; 27 uint64_t id; 28 uint64_t type; 29 size_t size; 30 char *buffer; 31 }; 32 #define to_elog_obj(x) container_of(x, struct elog_obj, kobj) 33 34 struct elog_attribute { 35 struct attribute attr; 36 ssize_t (*show)(struct elog_obj *elog, struct elog_attribute *attr, 37 char *buf); 38 ssize_t (*store)(struct elog_obj *elog, struct elog_attribute *attr, 39 const char *buf, size_t count); 40 }; 41 #define to_elog_attr(x) container_of(x, struct elog_attribute, attr) 42 43 static ssize_t elog_id_show(struct elog_obj *elog_obj, 44 struct elog_attribute *attr, 45 char *buf) 46 { 47 return sprintf(buf, "0x%llx\n", elog_obj->id); 48 } 49 50 static const char *elog_type_to_string(uint64_t type) 51 { 52 switch (type) { 53 case 0: return "PEL"; 54 default: return "unknown"; 55 } 56 } 57 58 static ssize_t elog_type_show(struct elog_obj *elog_obj, 59 struct elog_attribute *attr, 60 char *buf) 61 { 62 return sprintf(buf, "0x%llx %s\n", 63 elog_obj->type, 64 elog_type_to_string(elog_obj->type)); 65 } 66 67 static ssize_t elog_ack_show(struct elog_obj *elog_obj, 68 struct elog_attribute *attr, 69 char *buf) 70 { 71 return sprintf(buf, "ack - acknowledge log message\n"); 72 } 73 74 static ssize_t elog_ack_store(struct elog_obj *elog_obj, 75 struct elog_attribute *attr, 76 const char *buf, 77 size_t count) 78 { 79 opal_send_ack_elog(elog_obj->id); 80 sysfs_remove_file_self(&elog_obj->kobj, &attr->attr); 81 kobject_put(&elog_obj->kobj); 82 return count; 83 } 84 85 static struct elog_attribute id_attribute = 86 __ATTR(id, S_IRUGO, elog_id_show, NULL); 87 static struct elog_attribute type_attribute = 88 __ATTR(type, S_IRUGO, elog_type_show, NULL); 89 static struct elog_attribute ack_attribute = 90 __ATTR(acknowledge, 0660, elog_ack_show, elog_ack_store); 91 92 static struct kset *elog_kset; 93 94 static ssize_t elog_attr_show(struct kobject *kobj, 95 struct attribute *attr, 96 char *buf) 97 { 98 struct elog_attribute *attribute; 99 struct elog_obj *elog; 100 101 attribute = to_elog_attr(attr); 102 elog = to_elog_obj(kobj); 103 104 if (!attribute->show) 105 return -EIO; 106 107 return attribute->show(elog, attribute, buf); 108 } 109 110 static ssize_t elog_attr_store(struct kobject *kobj, 111 struct attribute *attr, 112 const char *buf, size_t len) 113 { 114 struct elog_attribute *attribute; 115 struct elog_obj *elog; 116 117 attribute = to_elog_attr(attr); 118 elog = to_elog_obj(kobj); 119 120 if (!attribute->store) 121 return -EIO; 122 123 return attribute->store(elog, attribute, buf, len); 124 } 125 126 static const struct sysfs_ops elog_sysfs_ops = { 127 .show = elog_attr_show, 128 .store = elog_attr_store, 129 }; 130 131 static void elog_release(struct kobject *kobj) 132 { 133 struct elog_obj *elog; 134 135 elog = to_elog_obj(kobj); 136 kfree(elog->buffer); 137 kfree(elog); 138 } 139 140 static struct attribute *elog_default_attrs[] = { 141 &id_attribute.attr, 142 &type_attribute.attr, 143 &ack_attribute.attr, 144 NULL, 145 }; 146 147 static struct kobj_type elog_ktype = { 148 .sysfs_ops = &elog_sysfs_ops, 149 .release = &elog_release, 150 .default_attrs = elog_default_attrs, 151 }; 152 153 /* Maximum size of a single log on FSP is 16KB */ 154 #define OPAL_MAX_ERRLOG_SIZE 16384 155 156 static ssize_t raw_attr_read(struct file *filep, struct kobject *kobj, 157 struct bin_attribute *bin_attr, 158 char *buffer, loff_t pos, size_t count) 159 { 160 int opal_rc; 161 162 struct elog_obj *elog = to_elog_obj(kobj); 163 164 /* We may have had an error reading before, so let's retry */ 165 if (!elog->buffer) { 166 elog->buffer = kzalloc(elog->size, GFP_KERNEL); 167 if (!elog->buffer) 168 return -EIO; 169 170 opal_rc = opal_read_elog(__pa(elog->buffer), 171 elog->size, elog->id); 172 if (opal_rc != OPAL_SUCCESS) { 173 pr_err("ELOG: log read failed for log-id=%llx\n", 174 elog->id); 175 kfree(elog->buffer); 176 elog->buffer = NULL; 177 return -EIO; 178 } 179 } 180 181 memcpy(buffer, elog->buffer + pos, count); 182 183 return count; 184 } 185 186 static struct elog_obj *create_elog_obj(uint64_t id, size_t size, uint64_t type) 187 { 188 struct elog_obj *elog; 189 int rc; 190 191 elog = kzalloc(sizeof(*elog), GFP_KERNEL); 192 if (!elog) 193 return NULL; 194 195 elog->kobj.kset = elog_kset; 196 197 kobject_init(&elog->kobj, &elog_ktype); 198 199 sysfs_bin_attr_init(&elog->raw_attr); 200 201 elog->raw_attr.attr.name = "raw"; 202 elog->raw_attr.attr.mode = 0400; 203 elog->raw_attr.size = size; 204 elog->raw_attr.read = raw_attr_read; 205 206 elog->id = id; 207 elog->size = size; 208 elog->type = type; 209 210 elog->buffer = kzalloc(elog->size, GFP_KERNEL); 211 212 if (elog->buffer) { 213 rc = opal_read_elog(__pa(elog->buffer), 214 elog->size, elog->id); 215 if (rc != OPAL_SUCCESS) { 216 pr_err("ELOG: log read failed for log-id=%llx\n", 217 elog->id); 218 kfree(elog->buffer); 219 elog->buffer = NULL; 220 } 221 } 222 223 rc = kobject_add(&elog->kobj, NULL, "0x%llx", id); 224 if (rc) { 225 kobject_put(&elog->kobj); 226 return NULL; 227 } 228 229 rc = sysfs_create_bin_file(&elog->kobj, &elog->raw_attr); 230 if (rc) { 231 kobject_put(&elog->kobj); 232 return NULL; 233 } 234 235 kobject_uevent(&elog->kobj, KOBJ_ADD); 236 237 return elog; 238 } 239 240 static irqreturn_t elog_event(int irq, void *data) 241 { 242 __be64 size; 243 __be64 id; 244 __be64 type; 245 uint64_t elog_size; 246 uint64_t log_id; 247 uint64_t elog_type; 248 int rc; 249 char name[2+16+1]; 250 struct kobject *kobj; 251 252 rc = opal_get_elog_size(&id, &size, &type); 253 if (rc != OPAL_SUCCESS) { 254 pr_err("ELOG: OPAL log info read failed\n"); 255 return IRQ_HANDLED; 256 } 257 258 elog_size = be64_to_cpu(size); 259 log_id = be64_to_cpu(id); 260 elog_type = be64_to_cpu(type); 261 262 WARN_ON(elog_size > OPAL_MAX_ERRLOG_SIZE); 263 264 if (elog_size >= OPAL_MAX_ERRLOG_SIZE) 265 elog_size = OPAL_MAX_ERRLOG_SIZE; 266 267 sprintf(name, "0x%llx", log_id); 268 269 /* we may get notified twice, let's handle 270 * that gracefully and not create two conflicting 271 * entries. 272 */ 273 kobj = kset_find_obj(elog_kset, name); 274 if (kobj) { 275 /* Drop reference added by kset_find_obj() */ 276 kobject_put(kobj); 277 return IRQ_HANDLED; 278 } 279 280 create_elog_obj(log_id, elog_size, elog_type); 281 282 return IRQ_HANDLED; 283 } 284 285 int __init opal_elog_init(void) 286 { 287 int rc = 0, irq; 288 289 /* ELOG not supported by firmware */ 290 if (!opal_check_token(OPAL_ELOG_READ)) 291 return -1; 292 293 elog_kset = kset_create_and_add("elog", NULL, opal_kobj); 294 if (!elog_kset) { 295 pr_warn("%s: failed to create elog kset\n", __func__); 296 return -1; 297 } 298 299 irq = opal_event_request(ilog2(OPAL_EVENT_ERROR_LOG_AVAIL)); 300 if (!irq) { 301 pr_err("%s: Can't register OPAL event irq (%d)\n", 302 __func__, irq); 303 return irq; 304 } 305 306 rc = request_threaded_irq(irq, NULL, elog_event, 307 IRQF_TRIGGER_HIGH | IRQF_ONESHOT, "opal-elog", NULL); 308 if (rc) { 309 pr_err("%s: Can't request OPAL event irq (%d)\n", 310 __func__, rc); 311 return rc; 312 } 313 314 /* We are now ready to pull error logs from opal. */ 315 if (opal_check_token(OPAL_ELOG_RESEND)) 316 opal_resend_pending_logs(); 317 318 return 0; 319 } 320