1 /*-
2 * Copyright (c) 2000, 2001 Michael Smith
3 * Copyright (c) 2000 BSDi
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27
28 #include <sys/cdefs.h>
29 #include "opt_acpi.h"
30 #include <sys/param.h>
31 #include <sys/bus.h>
32 #include <sys/eventhandler.h>
33 #include <sys/kernel.h>
34 #include <sys/module.h>
35 #include <sys/sysctl.h>
36 #include <sys/timetc.h>
37
38 #include <machine/bus.h>
39 #include <machine/resource.h>
40 #include <sys/rman.h>
41
42 #include <contrib/dev/acpica/include/acpi.h>
43 #include <contrib/dev/acpica/include/accommon.h>
44
45 #include <dev/acpica/acpivar.h>
46 #include <dev/pci/pcivar.h>
47
48 /*
49 * A timecounter based on the free-running ACPI timer.
50 *
51 * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>.
52 */
53
54 /* Hooks for the ACPI CA debugging infrastructure */
55 #define _COMPONENT ACPI_TIMER
56 ACPI_MODULE_NAME("TIMER")
57
58 static device_t acpi_timer_dev;
59 static struct resource *acpi_timer_reg;
60 static bus_space_handle_t acpi_timer_bsh;
61 static bus_space_tag_t acpi_timer_bst;
62 static eventhandler_tag acpi_timer_eh;
63
64 static u_int acpi_timer_frequency = 14318182 / 4;
65
66 /* Knob to disable acpi_timer device */
67 bool acpi_timer_disabled = false;
68
69 static void acpi_timer_identify(driver_t *driver, device_t parent);
70 static int acpi_timer_probe(device_t dev);
71 static int acpi_timer_attach(device_t dev);
72 static void acpi_timer_resume_handler(struct timecounter *);
73 static void acpi_timer_suspend_handler(struct timecounter *);
74 static u_int acpi_timer_get_timecount(struct timecounter *tc);
75 static u_int acpi_timer_get_timecount_safe(struct timecounter *tc);
76 static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS);
77 static void acpi_timer_boot_test(void);
78
79 static int acpi_timer_test(void);
80 static int acpi_timer_test_enabled = 0;
81 TUNABLE_INT("hw.acpi.timer_test_enabled", &acpi_timer_test_enabled);
82
83 static device_method_t acpi_timer_methods[] = {
84 DEVMETHOD(device_identify, acpi_timer_identify),
85 DEVMETHOD(device_probe, acpi_timer_probe),
86 DEVMETHOD(device_attach, acpi_timer_attach),
87
88 DEVMETHOD_END
89 };
90
91 static driver_t acpi_timer_driver = {
92 "acpi_timer",
93 acpi_timer_methods,
94 0,
95 };
96
97 DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, 0, 0);
98 MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1);
99
100 static struct timecounter acpi_timer_timecounter = {
101 acpi_timer_get_timecount_safe, /* get_timecount function */
102 0, /* no poll_pps */
103 0, /* no default counter_mask */
104 0, /* no default frequency */
105 "ACPI", /* name */
106 -1 /* quality (chosen later) */
107 };
108
109 static __inline uint32_t
acpi_timer_read(void)110 acpi_timer_read(void)
111 {
112
113 return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0));
114 }
115
116 /*
117 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources
118 * we will be using.
119 */
120 static void
acpi_timer_identify(driver_t * driver,device_t parent)121 acpi_timer_identify(driver_t *driver, device_t parent)
122 {
123 device_t dev;
124 rman_res_t rlen, rstart;
125 int rid, rtype;
126
127 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
128
129 if (acpi_disabled("timer") || (acpi_quirks & ACPI_Q_TIMER) ||
130 acpi_timer_dev || acpi_timer_disabled ||
131 AcpiGbl_FADT.PmTimerLength == 0)
132 return_VOID;
133
134 if ((dev = BUS_ADD_CHILD(parent, 2, "acpi_timer", 0)) == NULL) {
135 device_printf(parent, "could not add acpi_timer0\n");
136 return_VOID;
137 }
138 acpi_timer_dev = dev;
139
140 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) {
141 case ACPI_ADR_SPACE_SYSTEM_MEMORY:
142 rtype = SYS_RES_MEMORY;
143 break;
144 case ACPI_ADR_SPACE_SYSTEM_IO:
145 rtype = SYS_RES_IOPORT;
146 break;
147 default:
148 return_VOID;
149 }
150 rid = 0;
151 rlen = AcpiGbl_FADT.PmTimerLength;
152 rstart = AcpiGbl_FADT.XPmTimerBlock.Address;
153 if (bus_set_resource(dev, rtype, rid, rstart, rlen))
154 device_printf(dev, "couldn't set resource (%s 0x%jx+0x%jx)\n",
155 (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen);
156 return_VOID;
157 }
158
159 static int
acpi_timer_probe(device_t dev)160 acpi_timer_probe(device_t dev)
161 {
162 int i, j, rid, rtype;
163
164 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
165
166 if (dev != acpi_timer_dev)
167 return (ENXIO);
168
169 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) {
170 case ACPI_ADR_SPACE_SYSTEM_MEMORY:
171 rtype = SYS_RES_MEMORY;
172 break;
173 case ACPI_ADR_SPACE_SYSTEM_IO:
174 rtype = SYS_RES_IOPORT;
175 break;
176 default:
177 return (ENXIO);
178 }
179 rid = 0;
180 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE);
181 if (acpi_timer_reg == NULL) {
182 device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n",
183 (rtype == SYS_RES_IOPORT) ? "port" : "mem",
184 (u_long)AcpiGbl_FADT.XPmTimerBlock.Address);
185 return (ENXIO);
186 }
187 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg);
188 acpi_timer_bst = rman_get_bustag(acpi_timer_reg);
189 if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER)
190 acpi_timer_timecounter.tc_counter_mask = 0xffffffff;
191 else
192 acpi_timer_timecounter.tc_counter_mask = 0x00ffffff;
193 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
194 acpi_timer_timecounter.tc_flags = TC_FLAGS_SUSPEND_SAFE;
195 if (testenv("debug.acpi.timer_test"))
196 acpi_timer_boot_test();
197
198 /*
199 * If all tests of the counter succeed, use the ACPI-fast method. If
200 * at least one failed, default to using the safe routine, which reads
201 * the timer multiple times to get a consistent value before returning.
202 */
203 j = 0;
204 if (bootverbose)
205 printf("ACPI timer:");
206 for (i = 0; i < 10; i++)
207 j += acpi_timer_test();
208 if (bootverbose)
209 printf(" -> %d\n", j);
210 if (j == 10) {
211 acpi_timer_timecounter.tc_name = "ACPI-fast";
212 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount;
213 acpi_timer_timecounter.tc_quality = 900;
214 } else {
215 acpi_timer_timecounter.tc_name = "ACPI-safe";
216 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe;
217 acpi_timer_timecounter.tc_quality = 850;
218 }
219 tc_init(&acpi_timer_timecounter);
220
221 device_set_descf(dev, "%d-bit timer at %u.%06uMHz",
222 (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0 ? 32 : 24,
223 acpi_timer_frequency / 1000000, acpi_timer_frequency % 1000000);
224
225 /* Release the resource, we'll allocate it again during attach. */
226 bus_release_resource(dev, rtype, rid, acpi_timer_reg);
227 return (0);
228 }
229
230 static int
acpi_timer_attach(device_t dev)231 acpi_timer_attach(device_t dev)
232 {
233 int rid, rtype;
234
235 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
236
237 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) {
238 case ACPI_ADR_SPACE_SYSTEM_MEMORY:
239 rtype = SYS_RES_MEMORY;
240 break;
241 case ACPI_ADR_SPACE_SYSTEM_IO:
242 rtype = SYS_RES_IOPORT;
243 break;
244 default:
245 return (ENXIO);
246 }
247 rid = 0;
248 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE);
249 if (acpi_timer_reg == NULL)
250 return (ENXIO);
251 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg);
252 acpi_timer_bst = rman_get_bustag(acpi_timer_reg);
253
254 /* Register suspend event handler. */
255 if (EVENTHANDLER_REGISTER(power_suspend, acpi_timer_suspend_handler,
256 &acpi_timer_timecounter, EVENTHANDLER_PRI_LAST) == NULL)
257 device_printf(dev, "failed to register suspend event handler\n");
258
259 return (0);
260 }
261
262 static void
acpi_timer_resume_handler(struct timecounter * newtc)263 acpi_timer_resume_handler(struct timecounter *newtc)
264 {
265 struct timecounter *tc;
266
267 tc = timecounter;
268 if (tc != newtc) {
269 if (bootverbose)
270 device_printf(acpi_timer_dev,
271 "restoring timecounter, %s -> %s\n",
272 tc->tc_name, newtc->tc_name);
273 (void)newtc->tc_get_timecount(newtc);
274 timecounter = newtc;
275 }
276 }
277
278 static void
acpi_timer_suspend_handler(struct timecounter * newtc)279 acpi_timer_suspend_handler(struct timecounter *newtc)
280 {
281 struct timecounter *tc;
282
283 /* Deregister existing resume event handler. */
284 if (acpi_timer_eh != NULL) {
285 EVENTHANDLER_DEREGISTER(power_resume, acpi_timer_eh);
286 acpi_timer_eh = NULL;
287 }
288
289 if ((timecounter->tc_flags & TC_FLAGS_SUSPEND_SAFE) != 0) {
290 /*
291 * If we are using a suspend safe timecounter, don't
292 * save/restore it across suspend/resume.
293 */
294 return;
295 }
296
297 KASSERT(newtc == &acpi_timer_timecounter,
298 ("acpi_timer_suspend_handler: wrong timecounter"));
299
300 tc = timecounter;
301 if (tc != newtc) {
302 if (bootverbose)
303 device_printf(acpi_timer_dev,
304 "switching timecounter, %s -> %s\n",
305 tc->tc_name, newtc->tc_name);
306 (void)acpi_timer_read();
307 (void)acpi_timer_read();
308 timecounter = newtc;
309 acpi_timer_eh = EVENTHANDLER_REGISTER(power_resume,
310 acpi_timer_resume_handler, tc, EVENTHANDLER_PRI_LAST);
311 }
312 }
313
314 /*
315 * Fetch current time value from reliable hardware.
316 */
317 static u_int
acpi_timer_get_timecount(struct timecounter * tc)318 acpi_timer_get_timecount(struct timecounter *tc)
319 {
320 return (acpi_timer_read());
321 }
322
323 /*
324 * Fetch current time value from hardware that may not correctly
325 * latch the counter. We need to read until we have three monotonic
326 * samples and then use the middle one, otherwise we are not protected
327 * against the fact that the bits can be wrong in two directions. If
328 * we only cared about monosity, two reads would be enough.
329 */
330 static u_int
acpi_timer_get_timecount_safe(struct timecounter * tc)331 acpi_timer_get_timecount_safe(struct timecounter *tc)
332 {
333 u_int u1, u2, u3;
334
335 u2 = acpi_timer_read();
336 u3 = acpi_timer_read();
337 do {
338 u1 = u2;
339 u2 = u3;
340 u3 = acpi_timer_read();
341 } while (u1 > u2 || u2 > u3);
342
343 return (u2);
344 }
345
346 /*
347 * Timecounter freqency adjustment interface.
348 */
349 static int
acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS)350 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS)
351 {
352 int error;
353 u_int freq;
354
355 if (acpi_timer_timecounter.tc_frequency == 0)
356 return (EOPNOTSUPP);
357 freq = acpi_timer_frequency;
358 error = sysctl_handle_int(oidp, &freq, 0, req);
359 if (error == 0 && req->newptr != NULL) {
360 acpi_timer_frequency = freq;
361 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
362 }
363
364 return (error);
365 }
366
367 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq,
368 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
369 acpi_timer_sysctl_freq, "I",
370 "ACPI timer frequency");
371
372 /*
373 * Some ACPI timers are known or believed to suffer from implementation
374 * problems which can lead to erroneous values being read. This function
375 * tests for consistent results from the timer and returns 1 if it believes
376 * the timer is consistent, otherwise it returns 0.
377 *
378 * It appears the cause is that the counter is not latched to the PCI bus
379 * clock when read:
380 *
381 * ] 20. ACPI Timer Errata
382 * ]
383 * ] Problem: The power management timer may return improper result when
384 * ] read. Although the timer value settles properly after incrementing,
385 * ] while incrementing there is a 3nS window every 69.8nS where the
386 * ] timer value is indeterminate (a 4.2% chance that the data will be
387 * ] incorrect when read). As a result, the ACPI free running count up
388 * ] timer specification is violated due to erroneous reads. Implication:
389 * ] System hangs due to the "inaccuracy" of the timer when used by
390 * ] software for time critical events and delays.
391 * ]
392 * ] Workaround: Read the register twice and compare.
393 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed
394 * ] in the PIIX4M.
395 */
396 #define N 2000
397 static int
acpi_timer_test(void)398 acpi_timer_test(void)
399 {
400 uint32_t last, this;
401 int delta, max, max2, min, n;
402 register_t s;
403
404 /* Skip the test based on the hw.acpi.timer_test_enabled tunable. */
405 if (!acpi_timer_test_enabled)
406 return (1);
407
408 TSENTER();
409
410 min = INT32_MAX;
411 max = max2 = 0;
412
413 /* Test the timer with interrupts disabled to get accurate results. */
414 s = intr_disable();
415 last = acpi_timer_read();
416 for (n = 0; n < N; n++) {
417 this = acpi_timer_read();
418 delta = acpi_TimerDelta(this, last);
419 if (delta > max) {
420 max2 = max;
421 max = delta;
422 } else if (delta > max2)
423 max2 = delta;
424 if (delta < min)
425 min = delta;
426 last = this;
427 }
428 intr_restore(s);
429
430 delta = max2 - min;
431 if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO)
432 n = 0;
433 else if (min < 0 || max == 0 || max2 == 0)
434 n = 0;
435 else
436 n = 1;
437 if (bootverbose)
438 printf(" %d/%d", n, delta);
439
440 TSEXIT();
441
442 return (n);
443 }
444 #undef N
445
446 /*
447 * Test harness for verifying ACPI timer behaviour.
448 * Boot with debug.acpi.timer_test set to invoke this.
449 */
450 static void
acpi_timer_boot_test(void)451 acpi_timer_boot_test(void)
452 {
453 uint32_t u1, u2, u3;
454
455 u1 = acpi_timer_read();
456 u2 = acpi_timer_read();
457 u3 = acpi_timer_read();
458
459 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n");
460 for (;;) {
461 /*
462 * The failure case is where u3 > u1, but u2 does not fall between
463 * the two, ie. it contains garbage.
464 */
465 if (u3 > u1) {
466 if (u2 < u1 || u2 > u3)
467 device_printf(acpi_timer_dev,
468 "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n",
469 u1, u2, u3);
470 }
471 u1 = u2;
472 u2 = u3;
473 u3 = acpi_timer_read();
474 }
475 }
476