1139804Simp/*- 293835Stmm * Copyright (c) 1988 University of Utah. 393835Stmm * Copyright (c) 1982, 1990, 1993 4227723Slstewart * The Regents of the University of California. 5227723Slstewart * Copyright (c) 2011 The FreeBSD Foundation 6227723Slstewart * All rights reserved. 793835Stmm * 893835Stmm * This code is derived from software contributed to Berkeley by 993835Stmm * the Systems Programming Group of the University of Utah Computer 1093835Stmm * Science Department. 1193835Stmm * 12227723Slstewart * Portions of this software were developed by Julien Ridoux at the University 13227723Slstewart * of Melbourne under sponsorship from the FreeBSD Foundation. 14227723Slstewart * 1593835Stmm * Redistribution and use in source and binary forms, with or without 1693835Stmm * modification, are permitted provided that the following conditions 1793835Stmm * are met: 1893835Stmm * 1. Redistributions of source code must retain the above copyright 1993835Stmm * notice, this list of conditions and the following disclaimer. 2093835Stmm * 2. Redistributions in binary form must reproduce the above copyright 2193835Stmm * notice, this list of conditions and the following disclaimer in the 2293835Stmm * documentation and/or other materials provided with the distribution. 2393835Stmm * 4. Neither the name of the University nor the names of its contributors 2493835Stmm * may be used to endorse or promote products derived from this software 2593835Stmm * without specific prior written permission. 2693835Stmm * 2793835Stmm * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 2893835Stmm * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 2993835Stmm * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 3093835Stmm * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 3193835Stmm * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 3293835Stmm * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 3393835Stmm * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 3493835Stmm * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 3593835Stmm * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 3693835Stmm * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 3793835Stmm * SUCH DAMAGE. 3893835Stmm * 3993835Stmm * from: Utah $Hdr: clock.c 1.18 91/01/21$ 4093835Stmm * from: @(#)clock.c 8.2 (Berkeley) 1/12/94 4193835Stmm * from: NetBSD: clock_subr.c,v 1.6 2001/07/07 17:04:02 thorpej Exp 4293835Stmm * and 4393835Stmm * from: src/sys/i386/isa/clock.c,v 1.176 2001/09/04 4493835Stmm */ 4593835Stmm 4693835Stmm/* 4793835Stmm * Helpers for time-of-day clocks. This is useful for architectures that need 4893835Stmm * support multiple models of such clocks, and generally serves to make the 4993835Stmm * code more machine-independent. 5093835Stmm * If the clock in question can also be used as a time counter, the driver 5193835Stmm * needs to initiate this. 5293835Stmm * This code is not yet used by all architectures. 5393835Stmm */ 5493835Stmm 55116182Sobrien#include <sys/cdefs.h> 56116182Sobrien__FBSDID("$FreeBSD: stable/11/sys/kern/subr_rtc.c 338594 2018-09-11 18:35:08Z kib $"); 57116182Sobrien 58227723Slstewart#include "opt_ffclock.h" 59227723Slstewart 6093835Stmm#include <sys/param.h> 6193835Stmm#include <sys/systm.h> 6293835Stmm#include <sys/kernel.h> 6393835Stmm#include <sys/bus.h> 6493835Stmm#include <sys/clock.h> 65302251Skib#include <sys/lock.h> 66323447Sian#include <sys/malloc.h> 67323447Sian#include <sys/sx.h> 6893835Stmm#include <sys/sysctl.h> 69323447Sian#include <sys/taskqueue.h> 70227723Slstewart#ifdef FFCLOCK 71227723Slstewart#include <sys/timeffc.h> 72227723Slstewart#endif 7393835Stmm#include <sys/timetc.h> 7493835Stmm 7593835Stmm#include "clock_if.h" 7693835Stmm 77331503Sianstatic int show_io; 78331503SianSYSCTL_INT(_debug, OID_AUTO, clock_show_io, CTLFLAG_RWTUN, &show_io, 0, 79331503Sian "Enable debug printing of RTC clock I/O; 1=reads, 2=writes, 3=both."); 80331503Sian 81331503Sianstatic int sysctl_clock_do_io(SYSCTL_HANDLER_ARGS); 82331503SianSYSCTL_PROC(_debug, OID_AUTO, clock_do_io, CTLTYPE_INT | CTLFLAG_RW, 83331503Sian 0, 0, sysctl_clock_do_io, "I", 84331503Sian "Trigger one-time IO on RTC clocks; 1=read (and discard), 2=write"); 85331503Sian 86178429Sphk/* XXX: should be kern. now, it's no longer machdep. */ 87178429Sphkstatic int disable_rtc_set; 88211228SjkimSYSCTL_INT(_machdep, OID_AUTO, disable_rtc_set, CTLFLAG_RW, &disable_rtc_set, 89211228Sjkim 0, "Disallow adjusting time-of-day clock"); 90178429Sphk 91323447Sian/* 92323447Sian * An instance of a realtime clock. A list of these tracks all the registered 93323447Sian * clocks in the system. 94323447Sian * 95323447Sian * The resadj member is used to apply a "resolution adjustment" equal to half 96323447Sian * the clock's resolution, which is useful mainly on clocks with a whole-second 97323447Sian * resolution. Because the clock truncates the fractional part, adding half the 98323447Sian * resolution performs 4/5 rounding. The same adjustment is applied to the 99323447Sian * times returned from clock_gettime(), because the fraction returned will 100323447Sian * always be zero, but on average the actual fraction at the time of the call 101323447Sian * should be about .5. 102323447Sian */ 103323447Sianstruct rtc_instance { 104323447Sian device_t clockdev; 105323447Sian int resolution; 106323447Sian int flags; 107323447Sian u_int schedns; 108323447Sian struct timespec resadj; 109323447Sian struct timeout_task 110323447Sian stask; 111323447Sian LIST_ENTRY(rtc_instance) 112323447Sian rtc_entries; 113323447Sian}; 114323447Sian 115323447Sian/* 116323447Sian * Clocks are updated using a task running on taskqueue_thread. 117323447Sian */ 118323447Sianstatic void settime_task_func(void *arg, int pending); 119323447Sian 120323447Sian/* 121323447Sian * Registered clocks are kept in a list which is sorted by resolution; the more 122323447Sian * accurate clocks get the first shot at providing the time. 123323447Sian */ 124323447SianLIST_HEAD(rtc_listhead, rtc_instance); 125323447Sianstatic struct rtc_listhead rtc_list = LIST_HEAD_INITIALIZER(rtc_list); 126323447Sianstatic struct sx rtc_list_lock; 127323447SianSX_SYSINIT(rtc_list_lock_init, &rtc_list_lock, "rtc list"); 128323447Sian 129323447Sian/* 130323447Sian * On the task thread, invoke the clock_settime() method of the clock. Do so 131323447Sian * holding no locks, so that clock drivers are free to do whatever kind of 132323447Sian * locking or sleeping they need to. 133323447Sian */ 134323447Sianstatic void 135323447Siansettime_task_func(void *arg, int pending) 136323447Sian{ 137323447Sian struct timespec ts; 138323447Sian struct rtc_instance *rtc; 139338594Skib int error; 140323447Sian 141323447Sian rtc = arg; 142323447Sian if (!(rtc->flags & CLOCKF_SETTIME_NO_TS)) { 143323447Sian getnanotime(&ts); 144323447Sian if (!(rtc->flags & CLOCKF_SETTIME_NO_ADJ)) { 145323447Sian ts.tv_sec -= utc_offset(); 146323447Sian timespecadd(&ts, &rtc->resadj); 147323447Sian } 148323447Sian } else { 149323447Sian ts.tv_sec = 0; 150323447Sian ts.tv_nsec = 0; 151323447Sian } 152338594Skib error = CLOCK_SETTIME(rtc->clockdev, &ts); 153338594Skib if (error != 0 && bootverbose) 154338594Skib device_printf(rtc->clockdev, "CLOCK_SETTIME error %d\n", error); 155323447Sian} 156323447Sian 157331503Sianstatic void 158331503Sianclock_dbgprint_hdr(device_t dev, int rw) 159331503Sian{ 160331503Sian struct timespec now; 161331503Sian 162331503Sian getnanotime(&now); 163331503Sian device_printf(dev, "%s at ", (rw & CLOCK_DBG_READ) ? "read " : "write"); 164331503Sian clock_print_ts(&now, 9); 165331503Sian printf(": "); 166331503Sian} 167331503Sian 16893835Stmmvoid 169331503Sianclock_dbgprint_bcd(device_t dev, int rw, const struct bcd_clocktime *bct) 170331503Sian{ 171331503Sian 172331503Sian if (show_io & rw) { 173331503Sian clock_dbgprint_hdr(dev, rw); 174331503Sian clock_print_bcd(bct, 9); 175331503Sian printf("\n"); 176331503Sian } 177331503Sian} 178331503Sian 179331503Sianvoid 180331503Sianclock_dbgprint_ct(device_t dev, int rw, const struct clocktime *ct) 181331503Sian{ 182331503Sian 183331503Sian if (show_io & rw) { 184331503Sian clock_dbgprint_hdr(dev, rw); 185331503Sian clock_print_ct(ct, 9); 186331503Sian printf("\n"); 187331503Sian } 188331503Sian} 189331503Sian 190331503Sianvoid 191331503Sianclock_dbgprint_err(device_t dev, int rw, int err) 192331503Sian{ 193331503Sian 194331503Sian if (show_io & rw) { 195331503Sian clock_dbgprint_hdr(dev, rw); 196331503Sian printf("error = %d\n", err); 197331503Sian } 198331503Sian} 199331503Sian 200331503Sianvoid 201331503Sianclock_dbgprint_ts(device_t dev, int rw, const struct timespec *ts) 202331503Sian{ 203331503Sian 204331503Sian if (show_io & rw) { 205331503Sian clock_dbgprint_hdr(dev, rw); 206331503Sian clock_print_ts(ts, 9); 207331503Sian printf("\n"); 208331503Sian } 209331503Sian} 210331503Sian 211331503Sianvoid 212323447Sianclock_register_flags(device_t clockdev, long resolution, int flags) 21393835Stmm{ 214323447Sian struct rtc_instance *rtc, *newrtc; 21593835Stmm 216323447Sian newrtc = malloc(sizeof(*newrtc), M_DEVBUF, M_WAITOK); 217323447Sian newrtc->clockdev = clockdev; 218323447Sian newrtc->resolution = (int)resolution; 219323447Sian newrtc->flags = flags; 220323447Sian newrtc->schedns = 0; 221323447Sian newrtc->resadj.tv_sec = newrtc->resolution / 2 / 1000000; 222323447Sian newrtc->resadj.tv_nsec = newrtc->resolution / 2 % 1000000 * 1000; 223323447Sian TIMEOUT_TASK_INIT(taskqueue_thread, &newrtc->stask, 0, 224323447Sian settime_task_func, newrtc); 225323447Sian 226323447Sian sx_xlock(&rtc_list_lock); 227323447Sian if (LIST_EMPTY(&rtc_list)) { 228323447Sian LIST_INSERT_HEAD(&rtc_list, newrtc, rtc_entries); 229323447Sian } else { 230323447Sian LIST_FOREACH(rtc, &rtc_list, rtc_entries) { 231323447Sian if (rtc->resolution > newrtc->resolution) { 232323447Sian LIST_INSERT_BEFORE(rtc, newrtc, rtc_entries); 233323447Sian break; 234323447Sian } else if (LIST_NEXT(rtc, rtc_entries) == NULL) { 235323447Sian LIST_INSERT_AFTER(rtc, newrtc, rtc_entries); 236323447Sian break; 237323447Sian } 23893835Stmm } 23993835Stmm } 240323447Sian sx_xunlock(&rtc_list_lock); 241323447Sian 242323447Sian device_printf(clockdev, 243323447Sian "registered as a time-of-day clock, resolution %d.%6.6ds\n", 244323447Sian newrtc->resolution / 1000000, newrtc->resolution % 1000000); 24593835Stmm} 24693835Stmm 247323447Sianvoid 248323447Sianclock_register(device_t dev, long res) 249323447Sian{ 25093835Stmm 251323447Sian clock_register_flags(dev, res, 0); 252323447Sian} 253323447Sian 254323447Sianvoid 255323447Sianclock_unregister(device_t clockdev) 256323447Sian{ 257323447Sian struct rtc_instance *rtc, *tmp; 258323447Sian 259323447Sian sx_xlock(&rtc_list_lock); 260323447Sian LIST_FOREACH_SAFE(rtc, &rtc_list, rtc_entries, tmp) { 261323447Sian if (rtc->clockdev == clockdev) { 262323447Sian LIST_REMOVE(rtc, rtc_entries); 263323447Sian break; 264323447Sian } 265323447Sian } 266323447Sian sx_xunlock(&rtc_list_lock); 267323447Sian if (rtc != NULL) { 268323447Sian taskqueue_cancel_timeout(taskqueue_thread, &rtc->stask, NULL); 269323447Sian taskqueue_drain_timeout(taskqueue_thread, &rtc->stask); 270331503Sian free(rtc, M_DEVBUF); 271323447Sian } 272323447Sian} 273323447Sian 274323447Sianvoid 275323447Sianclock_schedule(device_t clockdev, u_int offsetns) 276323447Sian{ 277323447Sian struct rtc_instance *rtc; 278323447Sian 279323447Sian sx_xlock(&rtc_list_lock); 280323447Sian LIST_FOREACH(rtc, &rtc_list, rtc_entries) { 281323447Sian if (rtc->clockdev == clockdev) { 282323447Sian rtc->schedns = offsetns; 283323447Sian break; 284323447Sian } 285323447Sian } 286323447Sian sx_xunlock(&rtc_list_lock); 287323447Sian} 288323447Sian 289331503Sianstatic int 290331503Sianread_clocks(struct timespec *ts, bool debug_read) 291331503Sian{ 292331503Sian struct rtc_instance *rtc; 293331503Sian int error; 294331503Sian 295331503Sian error = ENXIO; 296331503Sian sx_xlock(&rtc_list_lock); 297331503Sian LIST_FOREACH(rtc, &rtc_list, rtc_entries) { 298331503Sian if ((error = CLOCK_GETTIME(rtc->clockdev, ts)) != 0) 299331503Sian continue; 300331503Sian if (ts->tv_sec < 0 || ts->tv_nsec < 0) { 301331503Sian error = EINVAL; 302331503Sian continue; 303331503Sian } 304331503Sian if (!(rtc->flags & CLOCKF_GETTIME_NO_ADJ)) { 305331503Sian timespecadd(ts, &rtc->resadj); 306331503Sian ts->tv_sec += utc_offset(); 307331503Sian } 308331503Sian if (!debug_read) { 309331503Sian if (bootverbose) 310331503Sian device_printf(rtc->clockdev, 311331503Sian "providing initial system time\n"); 312331503Sian break; 313331503Sian } 314331503Sian } 315331503Sian sx_xunlock(&rtc_list_lock); 316331503Sian return (error); 317331503Sian} 318331503Sian 31993835Stmm/* 320323447Sian * Initialize the system time. Must be called from a context which does not 321323447Sian * restrict any locking or sleeping that clock drivers may need to do. 322323447Sian * 323323447Sian * First attempt to get the time from a registered realtime clock. The clocks 324323447Sian * are queried in order of resolution until one provides the time. If no clock 325323447Sian * can provide the current time, use the 'base' time provided by the caller, if 326323447Sian * non-zero. The 'base' time is potentially highly inaccurate, such as the last 327323447Sian * known good value of the system clock, or even a filesystem last-updated 328323447Sian * timestamp. It is used to prevent system time from appearing to move 329323447Sian * backwards in logs. 33093835Stmm */ 33193835Stmmvoid 33293835Stmminittodr(time_t base) 33393835Stmm{ 334211228Sjkim struct timespec ts; 33593835Stmm int error; 33693835Stmm 337331503Sian error = read_clocks(&ts, false); 338323447Sian 339323447Sian /* 340323447Sian * Do not report errors from each clock; it is expected that some clocks 341323447Sian * cannot provide results in some situations. Only report problems when 342323447Sian * no clocks could provide the time. 343323447Sian */ 344323447Sian if (error != 0) { 345323447Sian switch (error) { 346323447Sian case ENXIO: 347323447Sian printf("Warning: no time-of-day clock registered, "); 348323447Sian break; 349323447Sian case EINVAL: 350323447Sian printf("Warning: bad time from time-of-day clock, "); 351323447Sian break; 352323447Sian default: 353323447Sian printf("Error reading time-of-day clock (%d), ", error); 354323447Sian break; 355323447Sian } 356323447Sian printf("system time will not be set accurately\n"); 357323447Sian ts.tv_sec = (base > 0) ? base : -1; 358323447Sian ts.tv_nsec = 0; 35993835Stmm } 36093835Stmm 361323447Sian if (ts.tv_sec >= 0) { 362323447Sian tc_setclock(&ts); 363227723Slstewart#ifdef FFCLOCK 364323447Sian ffclock_reset_clock(&ts); 365227723Slstewart#endif 36693835Stmm } 36793835Stmm} 36893835Stmm 36993835Stmm/* 370323447Sian * Write system time back to all registered clocks, unless disabled by admin. 371323447Sian * This can be called from a context that restricts locking and/or sleeping; the 372323447Sian * actual updating is done asynchronously on a task thread. 37393835Stmm */ 37493835Stmmvoid 375188055Simpresettodr(void) 37693835Stmm{ 377323447Sian struct timespec now; 378323447Sian struct rtc_instance *rtc; 379323447Sian sbintime_t sbt; 380323447Sian long waitns; 38193835Stmm 382323447Sian if (disable_rtc_set) 38393835Stmm return; 38493835Stmm 385323447Sian sx_xlock(&rtc_list_lock); 386323447Sian LIST_FOREACH(rtc, &rtc_list, rtc_entries) { 387323447Sian if (rtc->schedns != 0) { 388323447Sian getnanotime(&now); 389323447Sian waitns = rtc->schedns - now.tv_nsec; 390323447Sian if (waitns < 0) 391323447Sian waitns += 1000000000; 392323447Sian sbt = nstosbt(waitns); 393323447Sian } else 394323447Sian sbt = 0; 395323447Sian taskqueue_enqueue_timeout_sbt(taskqueue_thread, 396323447Sian &rtc->stask, -sbt, 0, C_PREL(31)); 397323447Sian } 398323447Sian sx_xunlock(&rtc_list_lock); 39993835Stmm} 400331503Sian 401331503Sianstatic int 402331503Siansysctl_clock_do_io(SYSCTL_HANDLER_ARGS) 403331503Sian{ 404331503Sian struct timespec ts_discard; 405331503Sian int error, value; 406331503Sian 407331503Sian value = 0; 408331503Sian error = sysctl_handle_int(oidp, &value, 0, req); 409331503Sian if (error != 0 || req->newptr == NULL) 410331503Sian return (error); 411331503Sian 412331503Sian switch (value) { 413331503Sian case CLOCK_DBG_READ: 414331503Sian if (read_clocks(&ts_discard, true) == ENXIO) 415331503Sian printf("No registered RTC clocks\n"); 416331503Sian break; 417331503Sian case CLOCK_DBG_WRITE: 418331503Sian resettodr(); 419331503Sian break; 420331503Sian default: 421331503Sian return (EINVAL); 422331503Sian } 423331503Sian 424331503Sian return (0); 425331503Sian} 426