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 __FBSDID("$FreeBSD$");
30
31 #include "opt_acpi.h"
32 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/eventhandler.h>
35 #include <sys/kernel.h>
36 #include <sys/module.h>
37 #include <sys/sysctl.h>
38 #include <sys/timetc.h>
39
40 #include <machine/bus.h>
41 #include <machine/resource.h>
42 #include <sys/rman.h>
43
44 #include <contrib/dev/acpica/include/acpi.h>
45 #include <contrib/dev/acpica/include/accommon.h>
46
47 #include <dev/acpica/acpivar.h>
48 #include <dev/pci/pcivar.h>
49
50 /*
51 * A timecounter based on the free-running ACPI timer.
52 *
53 * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>.
54 */
55
56 /* Hooks for the ACPI CA debugging infrastructure */
57 #define _COMPONENT ACPI_TIMER
58 ACPI_MODULE_NAME("TIMER")
59
60 static device_t acpi_timer_dev;
61 static struct resource *acpi_timer_reg;
62 static bus_space_handle_t acpi_timer_bsh;
63 static bus_space_tag_t acpi_timer_bst;
64 static eventhandler_tag acpi_timer_eh;
65
66 static u_int acpi_timer_frequency = 14318182 / 4;
67
68 /* Knob to disable acpi_timer device */
69 bool acpi_timer_disabled = false;
70
71 static void acpi_timer_identify(driver_t *driver, device_t parent);
72 static int acpi_timer_probe(device_t dev);
73 static int acpi_timer_attach(device_t dev);
74 static void acpi_timer_resume_handler(struct timecounter *);
75 static void acpi_timer_suspend_handler(struct timecounter *);
76 static u_int acpi_timer_get_timecount(struct timecounter *tc);
77 static u_int acpi_timer_get_timecount_safe(struct timecounter *tc);
78 static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS);
79 static void acpi_timer_boot_test(void);
80
81 static int acpi_timer_test(void);
82 static int acpi_timer_test_enabled = 0;
83 TUNABLE_INT("hw.acpi.timer_test_enabled", &acpi_timer_test_enabled);
84
85 static device_method_t acpi_timer_methods[] = {
86 DEVMETHOD(device_identify, acpi_timer_identify),
87 DEVMETHOD(device_probe, acpi_timer_probe),
88 DEVMETHOD(device_attach, acpi_timer_attach),
89
90 DEVMETHOD_END
91 };
92
93 static driver_t acpi_timer_driver = {
94 "acpi_timer",
95 acpi_timer_methods,
96 0,
97 };
98
99 DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, 0, 0);
100 MODULE_DEPEND(acpi_timer, acpi, 1, 1, 1);
101
102 static struct timecounter acpi_timer_timecounter = {
103 acpi_timer_get_timecount_safe, /* get_timecount function */
104 0, /* no poll_pps */
105 0, /* no default counter_mask */
106 0, /* no default frequency */
107 "ACPI", /* name */
108 -1 /* quality (chosen later) */
109 };
110
111 static __inline uint32_t
112 acpi_timer_read(void)
113 {
114
115 return (bus_space_read_4(acpi_timer_bst, acpi_timer_bsh, 0));
116 }
117
118 /*
119 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources
120 * we will be using.
121 */
122 static void
123 acpi_timer_identify(driver_t *driver, device_t parent)
124 {
125 device_t dev;
126 rman_res_t rlen, rstart;
127 int rid, rtype;
128
129 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
130
131 if (acpi_disabled("timer") || (acpi_quirks & ACPI_Q_TIMER) ||
132 acpi_timer_dev || acpi_timer_disabled ||
133 AcpiGbl_FADT.PmTimerLength == 0)
134 return_VOID;
135
136 if ((dev = BUS_ADD_CHILD(parent, 2, "acpi_timer", 0)) == NULL) {
137 device_printf(parent, "could not add acpi_timer0\n");
138 return_VOID;
139 }
140 acpi_timer_dev = dev;
141
142 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) {
143 case ACPI_ADR_SPACE_SYSTEM_MEMORY:
144 rtype = SYS_RES_MEMORY;
145 break;
146 case ACPI_ADR_SPACE_SYSTEM_IO:
147 rtype = SYS_RES_IOPORT;
148 break;
149 default:
150 return_VOID;
151 }
152 rid = 0;
153 rlen = AcpiGbl_FADT.PmTimerLength;
154 rstart = AcpiGbl_FADT.XPmTimerBlock.Address;
155 if (bus_set_resource(dev, rtype, rid, rstart, rlen))
156 device_printf(dev, "couldn't set resource (%s 0x%jx+0x%jx)\n",
157 (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart, rlen);
158 return_VOID;
159 }
160
161 static int
162 acpi_timer_probe(device_t dev)
163 {
164 char desc[40];
165 int i, j, rid, rtype;
166
167 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
168
169 if (dev != acpi_timer_dev)
170 return (ENXIO);
171
172 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) {
173 case ACPI_ADR_SPACE_SYSTEM_MEMORY:
174 rtype = SYS_RES_MEMORY;
175 break;
176 case ACPI_ADR_SPACE_SYSTEM_IO:
177 rtype = SYS_RES_IOPORT;
178 break;
179 default:
180 return (ENXIO);
181 }
182 rid = 0;
183 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE);
184 if (acpi_timer_reg == NULL) {
185 device_printf(dev, "couldn't allocate resource (%s 0x%lx)\n",
186 (rtype == SYS_RES_IOPORT) ? "port" : "mem",
187 (u_long)AcpiGbl_FADT.XPmTimerBlock.Address);
188 return (ENXIO);
189 }
190 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg);
191 acpi_timer_bst = rman_get_bustag(acpi_timer_reg);
192 if (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER)
193 acpi_timer_timecounter.tc_counter_mask = 0xffffffff;
194 else
195 acpi_timer_timecounter.tc_counter_mask = 0x00ffffff;
196 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
197 acpi_timer_timecounter.tc_flags = TC_FLAGS_SUSPEND_SAFE;
198 if (testenv("debug.acpi.timer_test"))
199 acpi_timer_boot_test();
200
201 /*
202 * If all tests of the counter succeed, use the ACPI-fast method. If
203 * at least one failed, default to using the safe routine, which reads
204 * the timer multiple times to get a consistent value before returning.
205 */
206 j = 0;
207 if (bootverbose)
208 printf("ACPI timer:");
209 for (i = 0; i < 10; i++)
210 j += acpi_timer_test();
211 if (bootverbose)
212 printf(" -> %d\n", j);
213 if (j == 10) {
214 acpi_timer_timecounter.tc_name = "ACPI-fast";
215 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount;
216 acpi_timer_timecounter.tc_quality = 900;
217 } else {
218 acpi_timer_timecounter.tc_name = "ACPI-safe";
219 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe;
220 acpi_timer_timecounter.tc_quality = 850;
221 }
222 tc_init(&acpi_timer_timecounter);
223
224 sprintf(desc, "%d-bit timer at %u.%06uMHz",
225 (AcpiGbl_FADT.Flags & ACPI_FADT_32BIT_TIMER) != 0 ? 32 : 24,
226 acpi_timer_frequency / 1000000, acpi_timer_frequency % 1000000);
227 device_set_desc_copy(dev, desc);
228
229 /* Release the resource, we'll allocate it again during attach. */
230 bus_release_resource(dev, rtype, rid, acpi_timer_reg);
231 return (0);
232 }
233
234 static int
235 acpi_timer_attach(device_t dev)
236 {
237 int rid, rtype;
238
239 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
240
241 switch (AcpiGbl_FADT.XPmTimerBlock.SpaceId) {
242 case ACPI_ADR_SPACE_SYSTEM_MEMORY:
243 rtype = SYS_RES_MEMORY;
244 break;
245 case ACPI_ADR_SPACE_SYSTEM_IO:
246 rtype = SYS_RES_IOPORT;
247 break;
248 default:
249 return (ENXIO);
250 }
251 rid = 0;
252 acpi_timer_reg = bus_alloc_resource_any(dev, rtype, &rid, RF_ACTIVE);
253 if (acpi_timer_reg == NULL)
254 return (ENXIO);
255 acpi_timer_bsh = rman_get_bushandle(acpi_timer_reg);
256 acpi_timer_bst = rman_get_bustag(acpi_timer_reg);
257
258 /* Register suspend event handler. */
259 if (EVENTHANDLER_REGISTER(power_suspend, acpi_timer_suspend_handler,
260 &acpi_timer_timecounter, EVENTHANDLER_PRI_LAST) == NULL)
261 device_printf(dev, "failed to register suspend event handler\n");
262
263 return (0);
264 }
265
266 static void
267 acpi_timer_resume_handler(struct timecounter *newtc)
268 {
269 struct timecounter *tc;
270
271 tc = timecounter;
272 if (tc != newtc) {
273 if (bootverbose)
274 device_printf(acpi_timer_dev,
275 "restoring timecounter, %s -> %s\n",
276 tc->tc_name, newtc->tc_name);
277 (void)newtc->tc_get_timecount(newtc);
278 timecounter = newtc;
279 }
280 }
281
282 static void
283 acpi_timer_suspend_handler(struct timecounter *newtc)
284 {
285 struct timecounter *tc;
286
287 /* Deregister existing resume event handler. */
288 if (acpi_timer_eh != NULL) {
289 EVENTHANDLER_DEREGISTER(power_resume, acpi_timer_eh);
290 acpi_timer_eh = NULL;
291 }
292
293 if ((timecounter->tc_flags & TC_FLAGS_SUSPEND_SAFE) != 0) {
294 /*
295 * If we are using a suspend safe timecounter, don't
296 * save/restore it across suspend/resume.
297 */
298 return;
299 }
300
301 KASSERT(newtc == &acpi_timer_timecounter,
302 ("acpi_timer_suspend_handler: wrong timecounter"));
303
304 tc = timecounter;
305 if (tc != newtc) {
306 if (bootverbose)
307 device_printf(acpi_timer_dev,
308 "switching timecounter, %s -> %s\n",
309 tc->tc_name, newtc->tc_name);
310 (void)acpi_timer_read();
311 (void)acpi_timer_read();
312 timecounter = newtc;
313 acpi_timer_eh = EVENTHANDLER_REGISTER(power_resume,
314 acpi_timer_resume_handler, tc, EVENTHANDLER_PRI_LAST);
315 }
316 }
317
318 /*
319 * Fetch current time value from reliable hardware.
320 */
321 static u_int
322 acpi_timer_get_timecount(struct timecounter *tc)
323 {
324 return (acpi_timer_read());
325 }
326
327 /*
328 * Fetch current time value from hardware that may not correctly
329 * latch the counter. We need to read until we have three monotonic
330 * samples and then use the middle one, otherwise we are not protected
331 * against the fact that the bits can be wrong in two directions. If
332 * we only cared about monosity, two reads would be enough.
333 */
334 static u_int
335 acpi_timer_get_timecount_safe(struct timecounter *tc)
336 {
337 u_int u1, u2, u3;
338
339 u2 = acpi_timer_read();
340 u3 = acpi_timer_read();
341 do {
342 u1 = u2;
343 u2 = u3;
344 u3 = acpi_timer_read();
345 } while (u1 > u2 || u2 > u3);
346
347 return (u2);
348 }
349
350 /*
351 * Timecounter freqency adjustment interface.
352 */
353 static int
354 acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS)
355 {
356 int error;
357 u_int freq;
358
359 if (acpi_timer_timecounter.tc_frequency == 0)
360 return (EOPNOTSUPP);
361 freq = acpi_timer_frequency;
362 error = sysctl_handle_int(oidp, &freq, 0, req);
363 if (error == 0 && req->newptr != NULL) {
364 acpi_timer_frequency = freq;
365 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
366 }
367
368 return (error);
369 }
370
371 SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq,
372 CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_MPSAFE, 0, 0,
373 acpi_timer_sysctl_freq, "I",
374 "ACPI timer frequency");
375
376 /*
377 * Some ACPI timers are known or believed to suffer from implementation
378 * problems which can lead to erroneous values being read. This function
379 * tests for consistent results from the timer and returns 1 if it believes
380 * the timer is consistent, otherwise it returns 0.
381 *
382 * It appears the cause is that the counter is not latched to the PCI bus
383 * clock when read:
384 *
385 * ] 20. ACPI Timer Errata
386 * ]
387 * ] Problem: The power management timer may return improper result when
388 * ] read. Although the timer value settles properly after incrementing,
389 * ] while incrementing there is a 3nS window every 69.8nS where the
390 * ] timer value is indeterminate (a 4.2% chance that the data will be
391 * ] incorrect when read). As a result, the ACPI free running count up
392 * ] timer specification is violated due to erroneous reads. Implication:
393 * ] System hangs due to the "inaccuracy" of the timer when used by
394 * ] software for time critical events and delays.
395 * ]
396 * ] Workaround: Read the register twice and compare.
397 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed
398 * ] in the PIIX4M.
399 */
400 #define N 2000
401 static int
402 acpi_timer_test(void)
403 {
404 uint32_t last, this;
405 int delta, max, max2, min, n;
406 register_t s;
407
408 /* Skip the test based on the hw.acpi.timer_test_enabled tunable. */
409 if (!acpi_timer_test_enabled)
410 return (1);
411
412 TSENTER();
413
414 min = INT32_MAX;
415 max = max2 = 0;
416
417 /* Test the timer with interrupts disabled to get accurate results. */
418 s = intr_disable();
419 last = acpi_timer_read();
420 for (n = 0; n < N; n++) {
421 this = acpi_timer_read();
422 delta = acpi_TimerDelta(this, last);
423 if (delta > max) {
424 max2 = max;
425 max = delta;
426 } else if (delta > max2)
427 max2 = delta;
428 if (delta < min)
429 min = delta;
430 last = this;
431 }
432 intr_restore(s);
433
434 delta = max2 - min;
435 if ((max - min > 8 || delta > 3) && vm_guest == VM_GUEST_NO)
436 n = 0;
437 else if (min < 0 || max == 0 || max2 == 0)
438 n = 0;
439 else
440 n = 1;
441 if (bootverbose)
442 printf(" %d/%d", n, delta);
443
444 TSEXIT();
445
446 return (n);
447 }
448 #undef N
449
450 /*
451 * Test harness for verifying ACPI timer behaviour.
452 * Boot with debug.acpi.timer_test set to invoke this.
453 */
454 static void
455 acpi_timer_boot_test(void)
456 {
457 uint32_t u1, u2, u3;
458
459 u1 = acpi_timer_read();
460 u2 = acpi_timer_read();
461 u3 = acpi_timer_read();
462
463 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n");
464 for (;;) {
465 /*
466 * The failure case is where u3 > u1, but u2 does not fall between
467 * the two, ie. it contains garbage.
468 */
469 if (u3 > u1) {
470 if (u2 < u1 || u2 > u3)
471 device_printf(acpi_timer_dev,
472 "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n",
473 u1, u2, u3);
474 }
475 u1 = u2;
476 u2 = u3;
477 u3 = acpi_timer_read();
478 }
479 }
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