1ca01d6ddSTony Luck /* 2ca01d6ddSTony Luck * Persistent Storage - platform driver interface parts. 3ca01d6ddSTony Luck * 4ca01d6ddSTony Luck * Copyright (C) 2010 Intel Corporation <tony.luck@intel.com> 5ca01d6ddSTony Luck * 6ca01d6ddSTony Luck * This program is free software; you can redistribute it and/or modify 7ca01d6ddSTony Luck * it under the terms of the GNU General Public License version 2 as 8ca01d6ddSTony Luck * published by the Free Software Foundation. 9ca01d6ddSTony Luck * 10ca01d6ddSTony Luck * This program is distributed in the hope that it will be useful, 11ca01d6ddSTony Luck * but WITHOUT ANY WARRANTY; without even the implied warranty of 12ca01d6ddSTony Luck * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13ca01d6ddSTony Luck * GNU General Public License for more details. 14ca01d6ddSTony Luck * 15ca01d6ddSTony Luck * You should have received a copy of the GNU General Public License 16ca01d6ddSTony Luck * along with this program; if not, write to the Free Software 17ca01d6ddSTony Luck * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 18ca01d6ddSTony Luck */ 19ca01d6ddSTony Luck 20ca01d6ddSTony Luck #include <linux/atomic.h> 21ca01d6ddSTony Luck #include <linux/types.h> 22ca01d6ddSTony Luck #include <linux/errno.h> 23ca01d6ddSTony Luck #include <linux/init.h> 24ca01d6ddSTony Luck #include <linux/kmsg_dump.h> 25ca01d6ddSTony Luck #include <linux/module.h> 26ca01d6ddSTony Luck #include <linux/pstore.h> 27ca01d6ddSTony Luck #include <linux/string.h> 286dda9266SLuck, Tony #include <linux/timer.h> 29ca01d6ddSTony Luck #include <linux/slab.h> 30ca01d6ddSTony Luck #include <linux/uaccess.h> 31abd4d558SDon Zickus #include <linux/hardirq.h> 326dda9266SLuck, Tony #include <linux/workqueue.h> 33ca01d6ddSTony Luck 34ca01d6ddSTony Luck #include "internal.h" 35ca01d6ddSTony Luck 36ca01d6ddSTony Luck /* 376dda9266SLuck, Tony * We defer making "oops" entries appear in pstore - see 386dda9266SLuck, Tony * whether the system is actually still running well enough 396dda9266SLuck, Tony * to let someone see the entry 406dda9266SLuck, Tony */ 416dda9266SLuck, Tony #define PSTORE_INTERVAL (60 * HZ) 426dda9266SLuck, Tony 436dda9266SLuck, Tony static int pstore_new_entry; 446dda9266SLuck, Tony 456dda9266SLuck, Tony static void pstore_timefunc(unsigned long); 466dda9266SLuck, Tony static DEFINE_TIMER(pstore_timer, pstore_timefunc, 0, 0); 476dda9266SLuck, Tony 486dda9266SLuck, Tony static void pstore_dowork(struct work_struct *); 496dda9266SLuck, Tony static DECLARE_WORK(pstore_work, pstore_dowork); 506dda9266SLuck, Tony 516dda9266SLuck, Tony /* 52ca01d6ddSTony Luck * pstore_lock just protects "psinfo" during 53ca01d6ddSTony Luck * calls to pstore_register() 54ca01d6ddSTony Luck */ 55ca01d6ddSTony Luck static DEFINE_SPINLOCK(pstore_lock); 56ca01d6ddSTony Luck static struct pstore_info *psinfo; 57ca01d6ddSTony Luck 58dee28e72SMatthew Garrett static char *backend; 59dee28e72SMatthew Garrett 60366f7e7aSLuck, Tony /* How much of the console log to snapshot */ 61ca01d6ddSTony Luck static unsigned long kmsg_bytes = 10240; 62ca01d6ddSTony Luck 63366f7e7aSLuck, Tony void pstore_set_kmsg_bytes(int bytes) 64ca01d6ddSTony Luck { 65366f7e7aSLuck, Tony kmsg_bytes = bytes; 66ca01d6ddSTony Luck } 67ca01d6ddSTony Luck 68ca01d6ddSTony Luck /* Tag each group of saved records with a sequence number */ 69ca01d6ddSTony Luck static int oopscount; 70ca01d6ddSTony Luck 71*381b872cSSeiji Aguchi static const char *get_reason_str(enum kmsg_dump_reason reason) 72*381b872cSSeiji Aguchi { 73*381b872cSSeiji Aguchi switch (reason) { 74*381b872cSSeiji Aguchi case KMSG_DUMP_PANIC: 75*381b872cSSeiji Aguchi return "Panic"; 76*381b872cSSeiji Aguchi case KMSG_DUMP_OOPS: 77*381b872cSSeiji Aguchi return "Oops"; 78*381b872cSSeiji Aguchi case KMSG_DUMP_EMERG: 79*381b872cSSeiji Aguchi return "Emergency"; 80*381b872cSSeiji Aguchi case KMSG_DUMP_RESTART: 81*381b872cSSeiji Aguchi return "Restart"; 82*381b872cSSeiji Aguchi case KMSG_DUMP_HALT: 83*381b872cSSeiji Aguchi return "Halt"; 84*381b872cSSeiji Aguchi case KMSG_DUMP_POWEROFF: 85*381b872cSSeiji Aguchi return "Poweroff"; 86*381b872cSSeiji Aguchi default: 87*381b872cSSeiji Aguchi return "Unknown"; 88*381b872cSSeiji Aguchi } 89*381b872cSSeiji Aguchi } 909f6af27fSTony Luck 91ca01d6ddSTony Luck /* 92ca01d6ddSTony Luck * callback from kmsg_dump. (s2,l2) has the most recently 93ca01d6ddSTony Luck * written bytes, older bytes are in (s1,l1). Save as much 94ca01d6ddSTony Luck * as we can from the end of the buffer. 95ca01d6ddSTony Luck */ 96ca01d6ddSTony Luck static void pstore_dump(struct kmsg_dumper *dumper, 97ca01d6ddSTony Luck enum kmsg_dump_reason reason, 98ca01d6ddSTony Luck const char *s1, unsigned long l1, 99ca01d6ddSTony Luck const char *s2, unsigned long l2) 100ca01d6ddSTony Luck { 101ca01d6ddSTony Luck unsigned long s1_start, s2_start; 102ca01d6ddSTony Luck unsigned long l1_cpy, l2_cpy; 103ca01d6ddSTony Luck unsigned long size, total = 0; 104*381b872cSSeiji Aguchi char *dst; 105*381b872cSSeiji Aguchi const char *why; 106ca01d6ddSTony Luck u64 id; 107b238b8faSChen Gong int hsize, ret; 108b94fdd07SMatthew Garrett unsigned int part = 1; 109abd4d558SDon Zickus unsigned long flags = 0; 110abd4d558SDon Zickus int is_locked = 0; 111ca01d6ddSTony Luck 112*381b872cSSeiji Aguchi why = get_reason_str(reason); 1139f6af27fSTony Luck 114abd4d558SDon Zickus if (in_nmi()) { 115abd4d558SDon Zickus is_locked = spin_trylock(&psinfo->buf_lock); 116abd4d558SDon Zickus if (!is_locked) 117abd4d558SDon Zickus pr_err("pstore dump routine blocked in NMI, may corrupt error record\n"); 118abd4d558SDon Zickus } else 119abd4d558SDon Zickus spin_lock_irqsave(&psinfo->buf_lock, flags); 120ca01d6ddSTony Luck oopscount++; 121ca01d6ddSTony Luck while (total < kmsg_bytes) { 122ca01d6ddSTony Luck dst = psinfo->buf; 12356280682SMatthew Garrett hsize = sprintf(dst, "%s#%d Part%d\n", why, oopscount, part); 124ca01d6ddSTony Luck size = psinfo->bufsize - hsize; 125ca01d6ddSTony Luck dst += hsize; 126ca01d6ddSTony Luck 127ca01d6ddSTony Luck l2_cpy = min(l2, size); 128ca01d6ddSTony Luck l1_cpy = min(l1, size - l2_cpy); 129ca01d6ddSTony Luck 130ca01d6ddSTony Luck if (l1_cpy + l2_cpy == 0) 131ca01d6ddSTony Luck break; 132ca01d6ddSTony Luck 133ca01d6ddSTony Luck s2_start = l2 - l2_cpy; 134ca01d6ddSTony Luck s1_start = l1 - l1_cpy; 135ca01d6ddSTony Luck 136ca01d6ddSTony Luck memcpy(dst, s1 + s1_start, l1_cpy); 137ca01d6ddSTony Luck memcpy(dst + l1_cpy, s2 + s2_start, l2_cpy); 138ca01d6ddSTony Luck 1393d6d8d20SKees Cook ret = psinfo->write(PSTORE_TYPE_DMESG, reason, &id, part, 14056280682SMatthew Garrett hsize + l1_cpy + l2_cpy, psinfo); 141b238b8faSChen Gong if (ret == 0 && reason == KMSG_DUMP_OOPS && pstore_is_mounted()) 1426dda9266SLuck, Tony pstore_new_entry = 1; 143ca01d6ddSTony Luck l1 -= l1_cpy; 144ca01d6ddSTony Luck l2 -= l2_cpy; 145ca01d6ddSTony Luck total += l1_cpy + l2_cpy; 14656280682SMatthew Garrett part++; 147ca01d6ddSTony Luck } 148abd4d558SDon Zickus if (in_nmi()) { 149abd4d558SDon Zickus if (is_locked) 150abd4d558SDon Zickus spin_unlock(&psinfo->buf_lock); 151abd4d558SDon Zickus } else 152abd4d558SDon Zickus spin_unlock_irqrestore(&psinfo->buf_lock, flags); 153ca01d6ddSTony Luck } 154ca01d6ddSTony Luck 155ca01d6ddSTony Luck static struct kmsg_dumper pstore_dumper = { 156ca01d6ddSTony Luck .dump = pstore_dump, 157ca01d6ddSTony Luck }; 158ca01d6ddSTony Luck 159ca01d6ddSTony Luck /* 160ca01d6ddSTony Luck * platform specific persistent storage driver registers with 161ca01d6ddSTony Luck * us here. If pstore is already mounted, call the platform 162ca01d6ddSTony Luck * read function right away to populate the file system. If not 163ca01d6ddSTony Luck * then the pstore mount code will call us later to fill out 164ca01d6ddSTony Luck * the file system. 165ca01d6ddSTony Luck * 166ca01d6ddSTony Luck * Register with kmsg_dump to save last part of console log on panic. 167ca01d6ddSTony Luck */ 168ca01d6ddSTony Luck int pstore_register(struct pstore_info *psi) 169ca01d6ddSTony Luck { 170ca01d6ddSTony Luck struct module *owner = psi->owner; 171ca01d6ddSTony Luck 172ca01d6ddSTony Luck spin_lock(&pstore_lock); 173ca01d6ddSTony Luck if (psinfo) { 174ca01d6ddSTony Luck spin_unlock(&pstore_lock); 175ca01d6ddSTony Luck return -EBUSY; 176ca01d6ddSTony Luck } 177dee28e72SMatthew Garrett 178dee28e72SMatthew Garrett if (backend && strcmp(backend, psi->name)) { 179dee28e72SMatthew Garrett spin_unlock(&pstore_lock); 180dee28e72SMatthew Garrett return -EINVAL; 181dee28e72SMatthew Garrett } 182dee28e72SMatthew Garrett 183ca01d6ddSTony Luck psinfo = psi; 184f6f82851SKees Cook mutex_init(&psinfo->read_mutex); 185ca01d6ddSTony Luck spin_unlock(&pstore_lock); 186ca01d6ddSTony Luck 187ca01d6ddSTony Luck if (owner && !try_module_get(owner)) { 188ca01d6ddSTony Luck psinfo = NULL; 189ca01d6ddSTony Luck return -EINVAL; 190ca01d6ddSTony Luck } 191ca01d6ddSTony Luck 192ca01d6ddSTony Luck if (pstore_is_mounted()) 1936dda9266SLuck, Tony pstore_get_records(0); 194ca01d6ddSTony Luck 195ca01d6ddSTony Luck kmsg_dump_register(&pstore_dumper); 196ca01d6ddSTony Luck 1976dda9266SLuck, Tony pstore_timer.expires = jiffies + PSTORE_INTERVAL; 1986dda9266SLuck, Tony add_timer(&pstore_timer); 1996dda9266SLuck, Tony 200ca01d6ddSTony Luck return 0; 201ca01d6ddSTony Luck } 202ca01d6ddSTony Luck EXPORT_SYMBOL_GPL(pstore_register); 203ca01d6ddSTony Luck 204ca01d6ddSTony Luck /* 2056dda9266SLuck, Tony * Read all the records from the persistent store. Create 2066dda9266SLuck, Tony * files in our filesystem. Don't warn about -EEXIST errors 2076dda9266SLuck, Tony * when we are re-scanning the backing store looking to add new 2086dda9266SLuck, Tony * error records. 209ca01d6ddSTony Luck */ 2106dda9266SLuck, Tony void pstore_get_records(int quiet) 211ca01d6ddSTony Luck { 212ca01d6ddSTony Luck struct pstore_info *psi = psinfo; 213f6f82851SKees Cook char *buf = NULL; 2148d38d74bSChen Gong ssize_t size; 215ca01d6ddSTony Luck u64 id; 216ca01d6ddSTony Luck enum pstore_type_id type; 217ca01d6ddSTony Luck struct timespec time; 21806cf91b4SChen Gong int failed = 0, rc; 219ca01d6ddSTony Luck 220ca01d6ddSTony Luck if (!psi) 221ca01d6ddSTony Luck return; 222ca01d6ddSTony Luck 223f6f82851SKees Cook mutex_lock(&psi->read_mutex); 2242174f6dfSKees Cook if (psi->open && psi->open(psi)) 22506cf91b4SChen Gong goto out; 22606cf91b4SChen Gong 227f6f82851SKees Cook while ((size = psi->read(&id, &type, &time, &buf, psi)) > 0) { 228f6f82851SKees Cook rc = pstore_mkfile(type, psi->name, id, buf, (size_t)size, 2296dda9266SLuck, Tony time, psi); 230f6f82851SKees Cook kfree(buf); 231f6f82851SKees Cook buf = NULL; 2326dda9266SLuck, Tony if (rc && (rc != -EEXIST || !quiet)) 233ca01d6ddSTony Luck failed++; 234ca01d6ddSTony Luck } 2352174f6dfSKees Cook if (psi->close) 23606cf91b4SChen Gong psi->close(psi); 23706cf91b4SChen Gong out: 238f6f82851SKees Cook mutex_unlock(&psi->read_mutex); 239ca01d6ddSTony Luck 240ca01d6ddSTony Luck if (failed) 241ca01d6ddSTony Luck printk(KERN_WARNING "pstore: failed to load %d record(s) from '%s'\n", 242ca01d6ddSTony Luck failed, psi->name); 243ca01d6ddSTony Luck } 244ca01d6ddSTony Luck 2456dda9266SLuck, Tony static void pstore_dowork(struct work_struct *work) 2466dda9266SLuck, Tony { 2476dda9266SLuck, Tony pstore_get_records(1); 2486dda9266SLuck, Tony } 2496dda9266SLuck, Tony 2506dda9266SLuck, Tony static void pstore_timefunc(unsigned long dummy) 2516dda9266SLuck, Tony { 2526dda9266SLuck, Tony if (pstore_new_entry) { 2536dda9266SLuck, Tony pstore_new_entry = 0; 2546dda9266SLuck, Tony schedule_work(&pstore_work); 2556dda9266SLuck, Tony } 2566dda9266SLuck, Tony 2576dda9266SLuck, Tony mod_timer(&pstore_timer, jiffies + PSTORE_INTERVAL); 2586dda9266SLuck, Tony } 2596dda9266SLuck, Tony 260dee28e72SMatthew Garrett module_param(backend, charp, 0444); 261dee28e72SMatthew Garrett MODULE_PARM_DESC(backend, "Pstore backend to use"); 262