2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2005 Bruno Ducrot
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
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.
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 * This driver is based upon information found by examining speedstep-0.5
29 * from Marc Lehman, which includes all the reverse engineering effort of
30 * Malik Martin (function 1 and 2 of the GSI).
32 * The correct way for the OS to take ownership from the BIOS was found by
33 * Hiroshi Miura (function 0 of the GSI).
35 * Finally, the int 15h call interface was (partially) documented by Intel.
37 * Many thanks to Jon Noack for testing and debugging this driver.
40 #include <sys/cdefs.h>
41 __FBSDID("$FreeBSD$");
43 #include <sys/param.h>
46 #include <sys/kernel.h>
47 #include <sys/module.h>
48 #include <sys/mutex.h>
49 #include <sys/systm.h>
51 #include <machine/bus.h>
52 #include <machine/cputypes.h>
53 #include <machine/md_var.h>
54 #include <machine/vm86.h>
56 #include <dev/pci/pcivar.h>
57 #include <dev/pci/pcireg.h>
62 #include "cpufreq_if.h"
65 #define DPRINT(dev, x...) device_printf(dev, x)
67 #define DPRINT(dev, x...)
76 struct cf_setting sets[2]; /* Only two settings. */
79 static char smist_magic[] = "Copyright (c) 1999 Intel Corporation";
81 static void smist_identify(driver_t *driver, device_t parent);
82 static int smist_probe(device_t dev);
83 static int smist_attach(device_t dev);
84 static int smist_detach(device_t dev);
85 static int smist_settings(device_t dev, struct cf_setting *sets,
87 static int smist_set(device_t dev, const struct cf_setting *set);
88 static int smist_get(device_t dev, struct cf_setting *set);
89 static int smist_type(device_t dev, int *type);
91 static device_method_t smist_methods[] = {
92 /* Device interface */
93 DEVMETHOD(device_identify, smist_identify),
94 DEVMETHOD(device_probe, smist_probe),
95 DEVMETHOD(device_attach, smist_attach),
96 DEVMETHOD(device_detach, smist_detach),
98 /* cpufreq interface */
99 DEVMETHOD(cpufreq_drv_set, smist_set),
100 DEVMETHOD(cpufreq_drv_get, smist_get),
101 DEVMETHOD(cpufreq_drv_type, smist_type),
102 DEVMETHOD(cpufreq_drv_settings, smist_settings),
107 static driver_t smist_driver = {
108 "smist", smist_methods, sizeof(struct smist_softc)
110 static devclass_t smist_devclass;
111 DRIVER_MODULE(smist, cpu, smist_driver, smist_devclass, 0, 0);
113 struct piix4_pci_device {
119 static struct piix4_pci_device piix4_pci_devices[] = {
120 {0x8086, 0x7113, "Intel PIIX4 ISA bridge"},
121 {0x8086, 0x719b, "Intel PIIX4 ISA bridge (embedded in MX440 chipset)"},
126 #define SET_OWNERSHIP 0
131 int15_gsic_call(int *sig, int *smi_cmd, int *command, int *smi_data, int *flags)
133 struct vm86frame vmf;
135 bzero(&vmf, sizeof(vmf));
136 vmf.vmf_eax = 0x0000E980; /* IST support */
137 vmf.vmf_edx = 0x47534943; /* 'GSIC' in ASCII */
138 vm86_intcall(0x15, &vmf);
140 if (vmf.vmf_eax == 0x47534943) {
142 *smi_cmd = vmf.vmf_ebx & 0xff;
143 *command = (vmf.vmf_ebx >> 16) & 0xff;
144 *smi_data = vmf.vmf_ecx;
145 *flags = vmf.vmf_edx;
157 /* Temporary structure to hold mapped page and status. */
158 struct set_ownership_data {
165 /* Perform actual SMI call to enable SpeedStep. */
167 set_ownership_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
169 struct set_ownership_data *data;
173 data->result = error;
177 /* Copy in the magic string and send it by writing to the SMI port. */
178 strlcpy(data->buf, smist_magic, PAGE_SIZE);
180 "movl $-1, %%edi\n\t"
182 : "=D" (data->result)
183 : "a" (data->command),
187 "S" ((uint32_t)segs[0].ds_addr)
192 set_ownership(device_t dev)
194 struct smist_softc *sc;
195 struct set_ownership_data cb_data;
200 * Specify the region to store the magic string. Since its address is
201 * passed to the BIOS in a 32-bit register, we have to make sure it is
202 * located in a physical page below 4 GB (i.e., for PAE.)
204 sc = device_get_softc(dev);
205 if (bus_dma_tag_create(/*parent*/ NULL,
206 /*alignment*/ PAGE_SIZE, /*no boundary*/ 0,
207 /*lowaddr*/ BUS_SPACE_MAXADDR_32BIT, /*highaddr*/ BUS_SPACE_MAXADDR,
208 NULL, NULL, /*maxsize*/ PAGE_SIZE, /*segments*/ 1,
209 /*maxsegsize*/ PAGE_SIZE, 0, busdma_lock_mutex, &Giant,
211 device_printf(dev, "can't create mem tag\n");
214 if (bus_dmamem_alloc(tag, &cb_data.buf, BUS_DMA_NOWAIT, &map) != 0) {
215 bus_dma_tag_destroy(tag);
216 device_printf(dev, "can't alloc mapped mem\n");
220 /* Load the physical page map and take ownership in the callback. */
221 cb_data.smi_cmd = sc->smi_cmd;
222 cb_data.command = sc->command;
223 if (bus_dmamap_load(tag, map, cb_data.buf, PAGE_SIZE, set_ownership_cb,
224 &cb_data, BUS_DMA_NOWAIT) != 0) {
225 bus_dmamem_free(tag, cb_data.buf, map);
226 bus_dma_tag_destroy(tag);
227 device_printf(dev, "can't load mem\n");
230 DPRINT(dev, "taking ownership over BIOS return %d\n", cb_data.result);
231 bus_dmamap_unload(tag, map);
232 bus_dmamem_free(tag, cb_data.buf, map);
233 bus_dma_tag_destroy(tag);
234 return (cb_data.result ? ENXIO : 0);
238 getset_state(struct smist_softc *sc, int *state, int function)
247 if (function != GET_STATE && function != SET_STATE)
250 DPRINT(sc->dev, "calling GSI\n");
253 "movl $-1, %%edi\n\t"
264 DPRINT(sc->dev, "GSI returned: eax %.8x ebx %.8x edi %.8x\n",
265 eax, new_state, result);
267 *state = new_state & 1;
283 smist_identify(driver_t *driver, device_t parent)
285 struct piix4_pci_device *id;
286 device_t piix4 = NULL;
288 if (resource_disabled("ichst", 0))
291 /* Check for a supported processor */
292 if (cpu_vendor_id != CPU_VENDOR_INTEL)
294 switch (cpu_id & 0xff0) {
295 case 0x680: /* Pentium III [coppermine] */
296 case 0x6a0: /* Pentium III [Tualatin] */
302 /* Check for a supported PCI-ISA bridge */
303 for (id = piix4_pci_devices; id->desc != NULL; ++id) {
304 if ((piix4 = pci_find_device(id->vendor, id->device)) != NULL)
311 printf("smist: found supported isa bridge %s\n", id->desc);
313 if (device_find_child(parent, "smist", -1) != NULL)
315 if (BUS_ADD_CHILD(parent, 30, "smist", -1) == NULL)
316 device_printf(parent, "smist: add child failed\n");
320 smist_probe(device_t dev)
322 struct smist_softc *sc;
323 device_t ichss_dev, perf_dev;
324 int sig, smi_cmd, command, smi_data, flags;
328 if (resource_disabled("smist", 0))
331 sc = device_get_softc(dev);
334 * If the ACPI perf or ICH SpeedStep drivers have attached and not
335 * just offering info, let them manage things.
337 perf_dev = device_find_child(device_get_parent(dev), "acpi_perf", -1);
338 if (perf_dev && device_is_attached(perf_dev)) {
339 rv = CPUFREQ_DRV_TYPE(perf_dev, &type);
340 if (rv == 0 && (type & CPUFREQ_FLAG_INFO_ONLY) == 0)
343 ichss_dev = device_find_child(device_get_parent(dev), "ichss", -1);
344 if (ichss_dev && device_is_attached(ichss_dev))
347 int15_gsic_call(&sig, &smi_cmd, &command, &smi_data, &flags);
349 device_printf(dev, "sig %.8x smi_cmd %.4x command %.2x "
350 "smi_data %.4x flags %.8x\n",
351 sig, smi_cmd, command, smi_data, flags);
354 sc->smi_cmd = smi_cmd;
355 sc->smi_data = smi_data;
358 * Sometimes int 15h 'GSIC' returns 0x80 for command, when
359 * it is actually 0x82. The Windows driver will overwrite
360 * this value given by the registry.
362 if (command == 0x80) {
364 "GSIC returned cmd 0x80, should be 0x82\n");
367 sc->command = (sig & 0xffffff00) | (command & 0xff);
370 /* Give some default values */
373 sc->command = 0x47534982;
377 device_set_desc(dev, "SpeedStep SMI");
383 smist_attach(device_t dev)
385 struct smist_softc *sc;
387 sc = device_get_softc(dev);
390 /* If we can't take ownership over BIOS, then bail out */
391 if (set_ownership(dev) != 0)
394 /* Setup some defaults for our exported settings. */
395 sc->sets[0].freq = CPUFREQ_VAL_UNKNOWN;
396 sc->sets[0].volts = CPUFREQ_VAL_UNKNOWN;
397 sc->sets[0].power = CPUFREQ_VAL_UNKNOWN;
398 sc->sets[0].lat = 1000;
399 sc->sets[0].dev = dev;
400 sc->sets[1] = sc->sets[0];
402 cpufreq_register(dev);
408 smist_detach(device_t dev)
411 return (cpufreq_unregister(dev));
415 smist_settings(device_t dev, struct cf_setting *sets, int *count)
417 struct smist_softc *sc;
418 struct cf_setting set;
421 if (sets == NULL || count == NULL)
427 sc = device_get_softc(dev);
430 * Estimate frequencies for both levels, temporarily switching to
431 * the other one if we haven't calibrated it yet.
433 for (i = 0; i < 2; i++) {
434 if (sc->sets[i].freq == CPUFREQ_VAL_UNKNOWN) {
435 first = (i == 0) ? 1 : 0;
436 smist_set(dev, &sc->sets[i]);
437 smist_get(dev, &set);
438 smist_set(dev, &sc->sets[first]);
442 bcopy(sc->sets, sets, sizeof(sc->sets));
449 smist_set(device_t dev, const struct cf_setting *set)
451 struct smist_softc *sc;
452 int rv, state, req_state, try;
454 /* Look up appropriate bit value based on frequency. */
455 sc = device_get_softc(dev);
456 if (CPUFREQ_CMP(set->freq, sc->sets[0].freq))
458 else if (CPUFREQ_CMP(set->freq, sc->sets[1].freq))
463 DPRINT(dev, "requested setting %d\n", req_state);
465 rv = getset_state(sc, &state, GET_STATE);
466 if (state == req_state)
471 rv = getset_state(sc, &req_state, SET_STATE);
473 /* Sleep for 200 microseconds. This value is just a guess. */
476 } while (rv && --try);
477 DPRINT(dev, "set_state return %d, tried %d times\n",
484 smist_get(device_t dev, struct cf_setting *set)
486 struct smist_softc *sc;
491 sc = device_get_softc(dev);
492 rv = getset_state(sc, &state, GET_STATE);
496 /* If we haven't changed settings yet, estimate the current value. */
497 if (sc->sets[state].freq == CPUFREQ_VAL_UNKNOWN) {
498 cpu_est_clockrate(0, &rate);
499 sc->sets[state].freq = rate / 1000000;
500 DPRINT(dev, "get calibrated new rate of %d\n",
501 sc->sets[state].freq);
503 *set = sc->sets[state];
509 smist_type(device_t dev, int *type)
515 *type = CPUFREQ_TYPE_ABSOLUTE;