This commit represents a major revamping of the clock interrupt and timebase
[dragonfly.git] / sys / dev / acpica / acpi_timer.c
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bf3e6b54
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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 * $FreeBSD: src/sys/dev/acpica/acpi_timer.c,v 1.24.2.1 2003/08/22 20:49:20 jhb Exp $
88c4d2f6 28 * $DragonFly: src/sys/dev/acpica/Attic/acpi_timer.c,v 1.2 2004/01/30 05:42:15 dillon Exp $
bf3e6b54 29 */
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30
31#ifdef NOTDEF /* Disabled */
32
bf3e6b54
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33#include "opt_acpi.h"
34#include <sys/param.h>
35#include <sys/bus.h>
36#include <sys/kernel.h>
37#include <sys/sysctl.h>
38#if __FreeBSD_version >= 500000
39#include <sys/timetc.h>
40#else
41#include <sys/time.h>
42#endif
43
44#include <machine/bus.h>
45#include <machine/resource.h>
46#include <sys/rman.h>
47
48#include "acpi.h"
49
50#include <dev/acpica/acpivar.h>
51#include <bus/pci/pcivar.h>
52
53/*
54 * A timecounter based on the free-running ACPI timer.
55 *
56 * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>.
57 */
58
59/*
60 * Hooks for the ACPI CA debugging infrastructure
61 */
62#define _COMPONENT ACPI_SYSTEM
63ACPI_MODULE_NAME("TIMER")
64
65static device_t acpi_timer_dev;
66struct resource *acpi_timer_reg;
67
68static u_int acpi_timer_frequency = 14318182/4;
69
70static void acpi_timer_identify(driver_t *driver, device_t parent);
71static int acpi_timer_probe(device_t dev);
72static int acpi_timer_attach(device_t dev);
73static unsigned acpi_timer_get_timecount(struct timecounter *tc);
74static unsigned acpi_timer_get_timecount_safe(struct timecounter *tc);
75static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS);
76static void acpi_timer_test(void);
77
78static u_int32_t read_counter(void);
79static int test_counter(void);
80
81/*
82 * Driver hung off ACPI.
83 */
84static device_method_t acpi_timer_methods[] = {
85 DEVMETHOD(device_identify, acpi_timer_identify),
86 DEVMETHOD(device_probe, acpi_timer_probe),
87 DEVMETHOD(device_attach, acpi_timer_attach),
88
89 {0, 0}
90};
91
92static driver_t acpi_timer_driver = {
93 "acpi_timer",
94 acpi_timer_methods,
95 0,
96};
97
98static devclass_t acpi_timer_devclass;
99DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0);
100
101/*
102 * Timecounter.
103 */
104static struct timecounter acpi_timer_timecounter = {
105 acpi_timer_get_timecount_safe,
106 0,
107 0xffffff,
108 0,
109 "ACPI"
110};
111
112
113static u_int32_t
114read_counter()
115{
116 bus_space_handle_t bsh;
117 bus_space_tag_t bst;
118 u_int32_t tv;
119
120 bsh = rman_get_bushandle(acpi_timer_reg);
121 bst = rman_get_bustag(acpi_timer_reg);
122 tv = bus_space_read_4(bst, bsh, 0);
123 bus_space_barrier(bst, bsh, 0, 4, BUS_SPACE_BARRIER_READ);
124 return (tv);
125}
126
127#define N 2000
128static int
129test_counter()
130{
131 int min, max, n, delta;
132 unsigned last, this;
133
134 min = 10000000;
135 max = 0;
136 last = read_counter();
137 for (n = 0; n < N; n++) {
138 this = read_counter();
139 delta = (this - last) & 0xffffff;
140 if (delta > max)
141 max = delta;
142 else if (delta < min)
143 min = delta;
144 last = this;
145 }
146 if (max - min > 2)
147 n = 0;
148 else if (min < 0 || max == 0)
149 n = 0;
150 else
151 n = 1;
152 if (bootverbose)
153 printf("ACPI timer looks %s min = %d, max = %d, width = %d\n",
154 n ? "GOOD" : "BAD ",
155 min, max, max - min);
156 return (n);
157}
158
159/*
160 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources
161 * we will be using.
162 */
163static void
164acpi_timer_identify(driver_t *driver, device_t parent)
165{
166 device_t dev;
167 char desc[40];
168 u_long rlen, rstart;
169 int i, j, rid, rtype;
170
171 ACPI_FUNCTION_TRACE((char *)(uintptr_t)__func__);
172
173 if (acpi_disabled("timer"))
174 return_VOID;
175
176 if (AcpiGbl_FADT == NULL)
177 return_VOID;
178
179 if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) {
180 device_printf(parent, "could not add acpi_timer0\n");
181 return_VOID;
182 }
183 acpi_timer_dev = dev;
184
185 rid = 0;
186 rlen = AcpiGbl_FADT->PmTmLen;
187 rtype = (AcpiGbl_FADT->XPmTmrBlk.AddressSpaceId)
188 ? SYS_RES_IOPORT : SYS_RES_MEMORY;
189 rstart = AcpiGbl_FADT->XPmTmrBlk.Address;
190 bus_set_resource(dev, rtype, rid, rstart, rlen);
191 acpi_timer_reg = bus_alloc_resource(dev, rtype, &rid, 0, ~0, 1, RF_ACTIVE);
192 if (acpi_timer_reg == NULL) {
193 device_printf(dev, "couldn't allocate I/O resource (%s 0x%lx)\n",
194 (rtype == SYS_RES_IOPORT) ? "port" : "mem", rstart);
195 return_VOID;
196 }
197 if (testenv("debug.acpi.timer_test"))
198 acpi_timer_test();
199
200 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
201 j = 0;
202 for(i = 0; i < 10; i++)
203 j += test_counter();
204 if (j == 10) {
205 acpi_timer_timecounter.tc_name = "ACPI-fast";
206 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount;
207 } else {
208 acpi_timer_timecounter.tc_name = "ACPI-safe";
209 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount_safe;
210 }
211 tc_init(&acpi_timer_timecounter);
212
213 sprintf(desc, "%d-bit timer at 3.579545MHz", (AcpiGbl_FADT->TmrValExt)
214 ? 32 : 24);
215 device_set_desc_copy(dev, desc);
216
217 return_VOID;
218}
219
220static int
221acpi_timer_probe(device_t dev)
222{
223 if (dev == acpi_timer_dev)
224 return(0);
225 return(ENXIO);
226}
227
228static int
229acpi_timer_attach(device_t dev)
230{
231 return(0);
232}
233
234/*
235 * Fetch current time value from reliable hardware.
236 */
237static unsigned
238acpi_timer_get_timecount(struct timecounter *tc)
239{
240 return (read_counter());
241}
242
243/*
244 * Fetch current time value from hardware that may not correctly
245 * latch the counter.
246 */
247static unsigned
248acpi_timer_get_timecount_safe(struct timecounter *tc)
249{
250 unsigned u1, u2, u3;
251
252 u2 = read_counter();
253 u3 = read_counter();
254 do {
255 u1 = u2;
256 u2 = u3;
257 u3 = read_counter();
258 } while (u1 > u2 || u2 > u3 || (u3 - u1) > 15);
259 return (u2);
260}
261
262/*
263 * Timecounter freqency adjustment interface.
264 */
265static int
266acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS)
267{
268 int error;
269 u_int freq;
270
271 if (acpi_timer_timecounter.tc_frequency == 0)
272 return (EOPNOTSUPP);
273 freq = acpi_timer_frequency;
274 error = sysctl_handle_int(oidp, &freq, sizeof(freq), req);
275 if (error == 0 && req->newptr != NULL) {
276 acpi_timer_frequency = freq;
277 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
278 }
279 return (error);
280}
281
282SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW,
283 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", "");
284
285/*
286 * Test harness for verifying ACPI timer behaviour.
287 * Boot with debug.acpi.timer_test set to invoke this.
288 */
289static void
290acpi_timer_test(void)
291{
292 u_int32_t u1, u2, u3;
293
294 u1 = read_counter();
295 u2 = read_counter();
296 u3 = read_counter();
297
298 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n");
299 for (;;) {
300 /*
301 * The failure case is where u3 > u1, but u2 does not fall between the two,
302 * ie. it contains garbage.
303 */
304 if (u3 > u1) {
305 if ((u2 < u1) || (u2 > u3))
306 device_printf(acpi_timer_dev, "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n",
307 u1, u2, u3);
308 }
309 u1 = u2;
310 u2 = u3;
311 u3 = read_counter();
312 }
313}
314
315/*
316 * Chipset workaround driver hung off PCI.
317 *
318 * Some ACPI timers are known or believed to suffer from implementation
319 * problems which can lead to erroneous values being read from the timer.
320 *
321 * Since we can't trust unknown chipsets, we default to a timer-read
322 * routine which compensates for the most common problem (as detailed
323 * in the excerpt from the Intel PIIX4 datasheet below).
324 *
325 * When we detect a known-functional chipset, we disable the workaround
326 * to improve speed.
327 *
328 * ] 20. ACPI Timer Errata
329 * ]
330 * ] Problem: The power management timer may return improper result when
331 * ] read. Although the timer value settles properly after incrementing,
332 * ] while incrementing there is a 3nS window every 69.8nS where the
333 * ] timer value is indeterminate (a 4.2% chance that the data will be
334 * ] incorrect when read). As a result, the ACPI free running count up
335 * ] timer specification is violated due to erroneous reads. Implication:
336 * ] System hangs due to the "inaccuracy" of the timer when used by
337 * ] software for time critical events and delays.
338 * ]
339 * ] Workaround: Read the register twice and compare.
340 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed
341 * ] in the PIIX4M.
342 *
343 * The counter is in other words not latched to the PCI bus clock when
344 * read. Notice the workaround isn't: We need to read until we have
345 * three monotonic samples and then use the middle one, otherwise we are
346 * not protected against the fact that the bits can be wrong in two
347 * directions. If we only cared about monosity two reads would be enough.
348 */
349
350#if 0
351static int acpi_timer_pci_probe(device_t dev);
352
353static device_method_t acpi_timer_pci_methods[] = {
354 DEVMETHOD(device_probe, acpi_timer_pci_probe),
355 {0, 0}
356};
357
358static driver_t acpi_timer_pci_driver = {
359 "acpi_timer_pci",
360 acpi_timer_pci_methods,
361 0,
362};
363
364devclass_t acpi_timer_pci_devclass;
365DRIVER_MODULE(acpi_timer_pci, pci, acpi_timer_pci_driver, acpi_timer_pci_devclass, 0, 0);
366
367/*
368 * Look at PCI devices going past; if we detect one we know contains
369 * a functional ACPI timer device, enable the faster timecounter read
370 * routine.
371 */
372static int
373acpi_timer_pci_probe(device_t dev)
374{
375 int vendor, device, revid;
376
377 vendor = pci_get_vendor(dev);
378 device = pci_get_device(dev);
379 revid = pci_get_revid(dev);
380
381 if (((vendor == 0x8086) && (device == 0x7113) && (revid >= 0x03)) || /* PIIX4M */
382 ((vendor == 0x8086) && (device == 0x719b)) || /* i440MX */
383 0) {
384
385 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount;
386 acpi_timer_timecounter.tc_name = "ACPI-fast";
387 if (bootverbose)
388 device_printf(acpi_timer_dev, "functional ACPI timer detected, enabling fast timecount interface\n");
389 }
390
391 return(ENXIO); /* we never match anything */
392}
393#endif
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394
395#endif