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 *
| 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: head/sys/dev/acpica/acpi_timer.c 89054 2002-01-08 06:46:01Z msmith $
| 27 * $FreeBSD: head/sys/dev/acpica/acpi_timer.c 91128 2002-02-23 05:31:38Z msmith $
|
28 */
29#include "opt_acpi.h"
30#include <sys/param.h>
31#include <sys/bus.h>
32#include <sys/kernel.h>
33#include <sys/sysctl.h>
34#include <sys/timetc.h>
35
36#include <machine/bus_pio.h>
37#include <machine/bus.h>
38#include <machine/resource.h>
39#include <sys/rman.h>
40
41#include "acpi.h"
42
43#include <acpica/acpivar.h>
44#include <pci/pcivar.h>
45
46/*
47 * A timecounter based on the free-running ACPI timer.
48 *
49 * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>.
50 */
51
52/*
53 * Hooks for the ACPI CA debugging infrastructure
54 */
55#define _COMPONENT ACPI_SYSTEM
| 28 */
29#include "opt_acpi.h"
30#include <sys/param.h>
31#include <sys/bus.h>
32#include <sys/kernel.h>
33#include <sys/sysctl.h>
34#include <sys/timetc.h>
35
36#include <machine/bus_pio.h>
37#include <machine/bus.h>
38#include <machine/resource.h>
39#include <sys/rman.h>
40
41#include "acpi.h"
42
43#include <acpica/acpivar.h>
44#include <pci/pcivar.h>
45
46/*
47 * A timecounter based on the free-running ACPI timer.
48 *
49 * Based on the i386-only mp_clock.c by <phk@FreeBSD.ORG>.
50 */
51
52/*
53 * Hooks for the ACPI CA debugging infrastructure
54 */
55#define _COMPONENT ACPI_SYSTEM
|
56MODULE_NAME("TIMER")
| 56ACPI_MODULE_NAME("TIMER")
|
57
58static device_t acpi_timer_dev;
59struct resource *acpi_timer_reg;
60#define TIMER_READ bus_space_read_4(rman_get_bustag(acpi_timer_reg), \
61 rman_get_bushandle(acpi_timer_reg), \
62 0)
63
64static u_int acpi_timer_frequency = 14318182/4;
65
66static void acpi_timer_identify(driver_t *driver, device_t parent);
67static int acpi_timer_probe(device_t dev);
68static int acpi_timer_attach(device_t dev);
69static unsigned acpi_timer_get_timecount(struct timecounter *tc);
70static unsigned acpi_timer_get_timecount_safe(struct timecounter *tc);
71static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS);
72static void acpi_timer_test(void);
73
74/*
75 * Driver hung off ACPI.
76 */
77static device_method_t acpi_timer_methods[] = {
78 DEVMETHOD(device_identify, acpi_timer_identify),
79 DEVMETHOD(device_probe, acpi_timer_probe),
80 DEVMETHOD(device_attach, acpi_timer_attach),
81
82 {0, 0}
83};
84
85static driver_t acpi_timer_driver = {
86 "acpi_timer",
87 acpi_timer_methods,
88 0,
89};
90
91static devclass_t acpi_timer_devclass;
92DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0);
93
94/*
95 * Timecounter.
96 */
97static struct timecounter acpi_timer_timecounter = {
98 acpi_timer_get_timecount_safe,
99 0,
100 0xffffff,
101 0,
102 "ACPI"
103};
104
105SYSCTL_OPAQUE(_debug, OID_AUTO, acpi_timecounter, CTLFLAG_RD,
106 &acpi_timer_timecounter, sizeof(acpi_timer_timecounter), "S,timecounter", "");
107
108/*
109 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources
110 * we will be using.
111 */
112static void
113acpi_timer_identify(driver_t *driver, device_t parent)
114{
115 device_t dev;
116 char desc[40];
117 int rid;
118
| 57
58static device_t acpi_timer_dev;
59struct resource *acpi_timer_reg;
60#define TIMER_READ bus_space_read_4(rman_get_bustag(acpi_timer_reg), \
61 rman_get_bushandle(acpi_timer_reg), \
62 0)
63
64static u_int acpi_timer_frequency = 14318182/4;
65
66static void acpi_timer_identify(driver_t *driver, device_t parent);
67static int acpi_timer_probe(device_t dev);
68static int acpi_timer_attach(device_t dev);
69static unsigned acpi_timer_get_timecount(struct timecounter *tc);
70static unsigned acpi_timer_get_timecount_safe(struct timecounter *tc);
71static int acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS);
72static void acpi_timer_test(void);
73
74/*
75 * Driver hung off ACPI.
76 */
77static device_method_t acpi_timer_methods[] = {
78 DEVMETHOD(device_identify, acpi_timer_identify),
79 DEVMETHOD(device_probe, acpi_timer_probe),
80 DEVMETHOD(device_attach, acpi_timer_attach),
81
82 {0, 0}
83};
84
85static driver_t acpi_timer_driver = {
86 "acpi_timer",
87 acpi_timer_methods,
88 0,
89};
90
91static devclass_t acpi_timer_devclass;
92DRIVER_MODULE(acpi_timer, acpi, acpi_timer_driver, acpi_timer_devclass, 0, 0);
93
94/*
95 * Timecounter.
96 */
97static struct timecounter acpi_timer_timecounter = {
98 acpi_timer_get_timecount_safe,
99 0,
100 0xffffff,
101 0,
102 "ACPI"
103};
104
105SYSCTL_OPAQUE(_debug, OID_AUTO, acpi_timecounter, CTLFLAG_RD,
106 &acpi_timer_timecounter, sizeof(acpi_timer_timecounter), "S,timecounter", "");
107
108/*
109 * Locate the ACPI timer using the FADT, set up and allocate the I/O resources
110 * we will be using.
111 */
112static void
113acpi_timer_identify(driver_t *driver, device_t parent)
114{
115 device_t dev;
116 char desc[40];
117 int rid;
118
|
119 FUNCTION_TRACE(__func__);
| 119 ACPI_FUNCTION_TRACE(__func__);
|
120
121 if (acpi_disabled("timer"))
122 return_VOID;
123
124 if (AcpiGbl_FADT == NULL)
125 return_VOID;
126
127 if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) {
128 device_printf(parent, "could not add acpi_timer0\n");
129 return_VOID;
130 }
131 acpi_timer_dev = dev;
132 rid = 0;
133 bus_set_resource(dev, SYS_RES_IOPORT, rid, AcpiGbl_FADT->V1_PmTmrBlk, sizeof(u_int32_t));
134 if ((acpi_timer_reg = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid, 0, ~0, 1, RF_ACTIVE)) == NULL) {
135 device_printf(dev, "couldn't allocate I/O resource (port 0x%x)\n", AcpiGbl_FADT->V1_PmTmrBlk);
136 return_VOID;
137 }
138 if (getenv("debug.acpi.timer_test") != NULL)
139 acpi_timer_test();
140
141 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount;
142 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
143 tc_init(&acpi_timer_timecounter);
144
145 sprintf(desc, "%d-bit timer at 3.579545MHz", AcpiGbl_FADT->TmrValExt ? 32 : 24);
146 device_set_desc_copy(dev, desc);
147
148#if 0
149 {
150 u_int64_t first;
151
152 first = rdtsc();
153 acpi_timer_get_timecount(NULL);
154 printf("acpi_timer_get_timecount %lld cycles\n", rdtsc() - first);
155
156 first = rdtsc();
157 acpi_timer_get_timecount_safe(NULL);
158 printf("acpi_timer_get_timecount_safe %lld cycles\n", rdtsc() - first);
159 }
160#endif
161
162 return_VOID;
163}
164
165static int
166acpi_timer_probe(device_t dev)
167{
168 if (dev == acpi_timer_dev)
169 return(0);
170 return(ENXIO);
171}
172
173static int
174acpi_timer_attach(device_t dev)
175{
176 return(0);
177}
178
179/*
180 * Fetch current time value from reliable hardware.
181 */
182static unsigned
183acpi_timer_get_timecount(struct timecounter *tc)
184{
185 return(TIMER_READ);
186}
187
188/*
189 * Fetch current time value from hardware that may not correctly
190 * latch the counter.
191 */
192static unsigned
193acpi_timer_get_timecount_safe(struct timecounter *tc)
194{
195 unsigned u1, u2, u3;
196
197 u2 = TIMER_READ;
198 u3 = TIMER_READ;
199 do {
200 u1 = u2;
201 u2 = u3;
202 u3 = TIMER_READ;
203 } while (u1 > u2 || u2 > u3);
204 return (u2);
205}
206
207/*
208 * Timecounter freqency adjustment interface.
209 */
210static int
211acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS)
212{
213 int error;
214 u_int freq;
215
216 if (acpi_timer_timecounter.tc_frequency == 0)
217 return (EOPNOTSUPP);
218 freq = acpi_timer_frequency;
219 error = sysctl_handle_int(oidp, &freq, sizeof(freq), req);
220 if (error == 0 && req->newptr != NULL) {
221 acpi_timer_frequency = freq;
222 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
223 tc_update(&acpi_timer_timecounter);
224 }
225 return (error);
226}
227
228SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW,
229 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", "");
230
231/*
232 * Test harness for verifying ACPI timer behaviour.
233 * Boot with debug.acpi.timer_test set to invoke this.
234 */
235static void
236acpi_timer_test(void)
237{
238 u_int32_t u1, u2, u3;
239
240 u1 = TIMER_READ;
241 u2 = TIMER_READ;
242 u3 = TIMER_READ;
243
244 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n");
245 for (;;) {
246 /*
247 * The failure case is where u3 > u1, but u2 does not fall between the two,
248 * ie. it contains garbage.
249 */
250 if (u3 > u1) {
251 if ((u2 < u1) || (u2 > u3))
252 device_printf(acpi_timer_dev, "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n",
253 u1, u2, u3);
254 }
255 u1 = u2;
256 u2 = u3;
257 u3 = TIMER_READ;
258 }
259}
260
261/*
262 * Chipset workaround driver hung off PCI.
263 *
264 * Some ACPI timers are known or believed to suffer from implementation
265 * problems which can lead to erroneous values being read from the timer.
266 *
267 * Since we can't trust unknown chipsets, we default to a timer-read
268 * routine which compensates for the most common problem (as detailed
269 * in the excerpt from the Intel PIIX4 datasheet below).
270 *
271 * When we detect a known-functional chipset, we disable the workaround
272 * to improve speed.
273 *
274 * ] 20. ACPI Timer Errata
275 * ]
276 * ] Problem: The power management timer may return improper result when
277 * ] read. Although the timer value settles properly after incrementing,
278 * ] while incrementing there is a 3nS window every 69.8nS where the
279 * ] timer value is indeterminate (a 4.2% chance that the data will be
280 * ] incorrect when read). As a result, the ACPI free running count up
281 * ] timer specification is violated due to erroneous reads. Implication:
282 * ] System hangs due to the "inaccuracy" of the timer when used by
283 * ] software for time critical events and delays.
284 * ]
285 * ] Workaround: Read the register twice and compare.
286 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed
287 * ] in the PIIX4M.
288 *
289 * The counter is in other words not latched to the PCI bus clock when
290 * read. Notice the workaround isn't: We need to read until we have
291 * three monotonic samples and then use the middle one, otherwise we are
292 * not protected against the fact that the bits can be wrong in two
293 * directions. If we only cared about monosity two reads would be enough.
294 */
295
296static int acpi_timer_pci_probe(device_t dev);
297
298static device_method_t acpi_timer_pci_methods[] = {
299 DEVMETHOD(device_probe, acpi_timer_pci_probe),
300 {0, 0}
301};
302
303static driver_t acpi_timer_pci_driver = {
304 "acpi_timer_pci",
305 acpi_timer_pci_methods,
306 0,
307};
308
309devclass_t acpi_timer_pci_devclass;
310DRIVER_MODULE(acpi_timer_pci, pci, acpi_timer_pci_driver, acpi_timer_pci_devclass, 0, 0);
311
312/*
313 * Look at PCI devices going past; if we detect one we know contains
314 * a functional ACPI timer device, enable the faster timecounter read
315 * routine.
316 */
317static int
318acpi_timer_pci_probe(device_t dev)
319{
320 int vendor, device, revid;
321
322 vendor = pci_get_vendor(dev);
323 device = pci_get_device(dev);
324 revid = pci_get_revid(dev);
325
326 if (((vendor == 0x8086) && (device == 0x7113) && (revid >= 0x03)) || /* PIIX4M */
327 ((vendor == 0x8086) && (device == 0x719b)) || /* i440MX */
328 0) {
329
330 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount;
331 acpi_timer_timecounter.tc_name = "ACPI-fast";
332 if (bootverbose)
333 device_printf(acpi_timer_dev, "functional ACPI timer detected, enabling fast timecount interface\n");
334 }
335
336 return(ENXIO); /* we never match anything */
337}
| 120
121 if (acpi_disabled("timer"))
122 return_VOID;
123
124 if (AcpiGbl_FADT == NULL)
125 return_VOID;
126
127 if ((dev = BUS_ADD_CHILD(parent, 0, "acpi_timer", 0)) == NULL) {
128 device_printf(parent, "could not add acpi_timer0\n");
129 return_VOID;
130 }
131 acpi_timer_dev = dev;
132 rid = 0;
133 bus_set_resource(dev, SYS_RES_IOPORT, rid, AcpiGbl_FADT->V1_PmTmrBlk, sizeof(u_int32_t));
134 if ((acpi_timer_reg = bus_alloc_resource(dev, SYS_RES_IOPORT, &rid, 0, ~0, 1, RF_ACTIVE)) == NULL) {
135 device_printf(dev, "couldn't allocate I/O resource (port 0x%x)\n", AcpiGbl_FADT->V1_PmTmrBlk);
136 return_VOID;
137 }
138 if (getenv("debug.acpi.timer_test") != NULL)
139 acpi_timer_test();
140
141 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount;
142 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
143 tc_init(&acpi_timer_timecounter);
144
145 sprintf(desc, "%d-bit timer at 3.579545MHz", AcpiGbl_FADT->TmrValExt ? 32 : 24);
146 device_set_desc_copy(dev, desc);
147
148#if 0
149 {
150 u_int64_t first;
151
152 first = rdtsc();
153 acpi_timer_get_timecount(NULL);
154 printf("acpi_timer_get_timecount %lld cycles\n", rdtsc() - first);
155
156 first = rdtsc();
157 acpi_timer_get_timecount_safe(NULL);
158 printf("acpi_timer_get_timecount_safe %lld cycles\n", rdtsc() - first);
159 }
160#endif
161
162 return_VOID;
163}
164
165static int
166acpi_timer_probe(device_t dev)
167{
168 if (dev == acpi_timer_dev)
169 return(0);
170 return(ENXIO);
171}
172
173static int
174acpi_timer_attach(device_t dev)
175{
176 return(0);
177}
178
179/*
180 * Fetch current time value from reliable hardware.
181 */
182static unsigned
183acpi_timer_get_timecount(struct timecounter *tc)
184{
185 return(TIMER_READ);
186}
187
188/*
189 * Fetch current time value from hardware that may not correctly
190 * latch the counter.
191 */
192static unsigned
193acpi_timer_get_timecount_safe(struct timecounter *tc)
194{
195 unsigned u1, u2, u3;
196
197 u2 = TIMER_READ;
198 u3 = TIMER_READ;
199 do {
200 u1 = u2;
201 u2 = u3;
202 u3 = TIMER_READ;
203 } while (u1 > u2 || u2 > u3);
204 return (u2);
205}
206
207/*
208 * Timecounter freqency adjustment interface.
209 */
210static int
211acpi_timer_sysctl_freq(SYSCTL_HANDLER_ARGS)
212{
213 int error;
214 u_int freq;
215
216 if (acpi_timer_timecounter.tc_frequency == 0)
217 return (EOPNOTSUPP);
218 freq = acpi_timer_frequency;
219 error = sysctl_handle_int(oidp, &freq, sizeof(freq), req);
220 if (error == 0 && req->newptr != NULL) {
221 acpi_timer_frequency = freq;
222 acpi_timer_timecounter.tc_frequency = acpi_timer_frequency;
223 tc_update(&acpi_timer_timecounter);
224 }
225 return (error);
226}
227
228SYSCTL_PROC(_machdep, OID_AUTO, acpi_timer_freq, CTLTYPE_INT | CTLFLAG_RW,
229 0, sizeof(u_int), acpi_timer_sysctl_freq, "I", "");
230
231/*
232 * Test harness for verifying ACPI timer behaviour.
233 * Boot with debug.acpi.timer_test set to invoke this.
234 */
235static void
236acpi_timer_test(void)
237{
238 u_int32_t u1, u2, u3;
239
240 u1 = TIMER_READ;
241 u2 = TIMER_READ;
242 u3 = TIMER_READ;
243
244 device_printf(acpi_timer_dev, "timer test in progress, reboot to quit.\n");
245 for (;;) {
246 /*
247 * The failure case is where u3 > u1, but u2 does not fall between the two,
248 * ie. it contains garbage.
249 */
250 if (u3 > u1) {
251 if ((u2 < u1) || (u2 > u3))
252 device_printf(acpi_timer_dev, "timer is not monotonic: 0x%08x,0x%08x,0x%08x\n",
253 u1, u2, u3);
254 }
255 u1 = u2;
256 u2 = u3;
257 u3 = TIMER_READ;
258 }
259}
260
261/*
262 * Chipset workaround driver hung off PCI.
263 *
264 * Some ACPI timers are known or believed to suffer from implementation
265 * problems which can lead to erroneous values being read from the timer.
266 *
267 * Since we can't trust unknown chipsets, we default to a timer-read
268 * routine which compensates for the most common problem (as detailed
269 * in the excerpt from the Intel PIIX4 datasheet below).
270 *
271 * When we detect a known-functional chipset, we disable the workaround
272 * to improve speed.
273 *
274 * ] 20. ACPI Timer Errata
275 * ]
276 * ] Problem: The power management timer may return improper result when
277 * ] read. Although the timer value settles properly after incrementing,
278 * ] while incrementing there is a 3nS window every 69.8nS where the
279 * ] timer value is indeterminate (a 4.2% chance that the data will be
280 * ] incorrect when read). As a result, the ACPI free running count up
281 * ] timer specification is violated due to erroneous reads. Implication:
282 * ] System hangs due to the "inaccuracy" of the timer when used by
283 * ] software for time critical events and delays.
284 * ]
285 * ] Workaround: Read the register twice and compare.
286 * ] Status: This will not be fixed in the PIIX4 or PIIX4E, it is fixed
287 * ] in the PIIX4M.
288 *
289 * The counter is in other words not latched to the PCI bus clock when
290 * read. Notice the workaround isn't: We need to read until we have
291 * three monotonic samples and then use the middle one, otherwise we are
292 * not protected against the fact that the bits can be wrong in two
293 * directions. If we only cared about monosity two reads would be enough.
294 */
295
296static int acpi_timer_pci_probe(device_t dev);
297
298static device_method_t acpi_timer_pci_methods[] = {
299 DEVMETHOD(device_probe, acpi_timer_pci_probe),
300 {0, 0}
301};
302
303static driver_t acpi_timer_pci_driver = {
304 "acpi_timer_pci",
305 acpi_timer_pci_methods,
306 0,
307};
308
309devclass_t acpi_timer_pci_devclass;
310DRIVER_MODULE(acpi_timer_pci, pci, acpi_timer_pci_driver, acpi_timer_pci_devclass, 0, 0);
311
312/*
313 * Look at PCI devices going past; if we detect one we know contains
314 * a functional ACPI timer device, enable the faster timecounter read
315 * routine.
316 */
317static int
318acpi_timer_pci_probe(device_t dev)
319{
320 int vendor, device, revid;
321
322 vendor = pci_get_vendor(dev);
323 device = pci_get_device(dev);
324 revid = pci_get_revid(dev);
325
326 if (((vendor == 0x8086) && (device == 0x7113) && (revid >= 0x03)) || /* PIIX4M */
327 ((vendor == 0x8086) && (device == 0x719b)) || /* i440MX */
328 0) {
329
330 acpi_timer_timecounter.tc_get_timecount = acpi_timer_get_timecount;
331 acpi_timer_timecounter.tc_name = "ACPI-fast";
332 if (bootverbose)
333 device_printf(acpi_timer_dev, "functional ACPI timer detected, enabling fast timecount interface\n");
334 }
335
336 return(ENXIO); /* we never match anything */
337}
|