1 // SPDX-License-Identifier: GPL-2.0-only
3 * (C) 2001-2004 Dave Jones.
4 * (C) 2002 Padraig Brady. <padraig@antefacto.com>
6 * Based upon datasheets & sample CPUs kindly provided by VIA.
8 * VIA have currently 3 different versions of Longhaul.
9 * Version 1 (Longhaul) uses the BCR2 MSR at 0x1147.
10 * It is present only in Samuel 1 (C5A), Samuel 2 (C5B) stepping 0.
11 * Version 2 of longhaul is backward compatible with v1, but adds
12 * LONGHAUL MSR for purpose of both frequency and voltage scaling.
13 * Present in Samuel 2 (steppings 1-7 only) (C5B), and Ezra (C5C).
14 * Version 3 of longhaul got renamed to Powersaver and redesigned
15 * to use only the POWERSAVER MSR at 0x110a.
16 * It is present in Ezra-T (C5M), Nehemiah (C5X) and above.
17 * It's pretty much the same feature wise to longhaul v2, though
18 * there is provision for scaling FSB too, but this doesn't work
19 * too well in practice so we don't even try to use this.
21 * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous*
24 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/moduleparam.h>
29 #include <linux/init.h>
30 #include <linux/cpufreq.h>
31 #include <linux/pci.h>
32 #include <linux/slab.h>
33 #include <linux/string.h>
34 #include <linux/delay.h>
35 #include <linux/timex.h>
37 #include <linux/acpi.h>
40 #include <asm/cpu_device_id.h>
41 #include <acpi/processor.h>
45 #define TYPE_LONGHAUL_V1 1
46 #define TYPE_LONGHAUL_V2 2
47 #define TYPE_POWERSAVER 3
53 #define CPU_NEHEMIAH 5
54 #define CPU_NEHEMIAH_C 6
57 #define USE_ACPI_C3 (1 << 1)
58 #define USE_NORTHBRIDGE (1 << 2)
61 static unsigned int numscales = 16;
62 static unsigned int fsb;
64 static const struct mV_pos *vrm_mV_table;
65 static const unsigned char *mV_vrm_table;
67 static unsigned int highest_speed, lowest_speed; /* kHz */
68 static unsigned int minmult, maxmult;
69 static int can_scale_voltage;
70 static struct acpi_processor *pr;
71 static struct acpi_processor_cx *cx;
72 static u32 acpi_regs_addr;
73 static u8 longhaul_flags;
74 static unsigned int longhaul_index;
76 /* Module parameters */
77 static int scale_voltage;
78 static int disable_acpi_c3;
79 static int revid_errata;
82 /* Clock ratios multiplied by 10 */
85 static int longhaul_version;
86 static struct cpufreq_frequency_table *longhaul_table;
88 static char speedbuffer[8];
90 static char *print_speed(int speed)
93 snprintf(speedbuffer, sizeof(speedbuffer), "%dMHz", speed);
98 snprintf(speedbuffer, sizeof(speedbuffer),
101 snprintf(speedbuffer, sizeof(speedbuffer),
102 "%d.%dGHz", speed/1000, (speed%1000)/100);
108 static unsigned int calc_speed(int mult)
119 static int longhaul_get_cpu_mult(void)
121 unsigned long invalue = 0, lo, hi;
123 rdmsr(MSR_IA32_EBL_CR_POWERON, lo, hi);
124 invalue = (lo & (1<<22|1<<23|1<<24|1<<25))>>22;
125 if (longhaul_version == TYPE_LONGHAUL_V2 ||
126 longhaul_version == TYPE_POWERSAVER) {
130 return eblcr[invalue];
133 /* For processor with BCR2 MSR */
135 static void do_longhaul1(unsigned int mults_index)
139 rdmsrl(MSR_VIA_BCR2, bcr2.val);
140 /* Enable software clock multiplier */
141 bcr2.bits.ESOFTBF = 1;
142 bcr2.bits.CLOCKMUL = mults_index & 0xff;
144 /* Sync to timer tick */
146 /* Change frequency on next halt or sleep */
147 wrmsrl(MSR_VIA_BCR2, bcr2.val);
148 /* Invoke transition */
149 ACPI_FLUSH_CPU_CACHE();
152 /* Disable software clock multiplier */
154 rdmsrl(MSR_VIA_BCR2, bcr2.val);
155 bcr2.bits.ESOFTBF = 0;
156 wrmsrl(MSR_VIA_BCR2, bcr2.val);
159 /* For processor with Longhaul MSR */
161 static void do_powersaver(int cx_address, unsigned int mults_index,
164 union msr_longhaul longhaul;
167 rdmsrl(MSR_VIA_LONGHAUL, longhaul.val);
168 /* Setup new frequency */
170 longhaul.bits.RevisionKey = longhaul.bits.RevisionID;
172 longhaul.bits.RevisionKey = 0;
173 longhaul.bits.SoftBusRatio = mults_index & 0xf;
174 longhaul.bits.SoftBusRatio4 = (mults_index & 0x10) >> 4;
175 /* Setup new voltage */
176 if (can_scale_voltage)
177 longhaul.bits.SoftVID = (mults_index >> 8) & 0x1f;
178 /* Sync to timer tick */
180 /* Raise voltage if necessary */
181 if (can_scale_voltage && dir) {
182 longhaul.bits.EnableSoftVID = 1;
183 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
186 ACPI_FLUSH_CPU_CACHE();
189 ACPI_FLUSH_CPU_CACHE();
192 /* Dummy op - must do something useless after P_LVL3
194 t = inl(acpi_gbl_FADT.xpm_timer_block.address);
196 longhaul.bits.EnableSoftVID = 0;
197 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
200 /* Change frequency on next halt or sleep */
201 longhaul.bits.EnableSoftBusRatio = 1;
202 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
204 ACPI_FLUSH_CPU_CACHE();
207 ACPI_FLUSH_CPU_CACHE();
210 /* Dummy op - must do something useless after P_LVL3 read */
211 t = inl(acpi_gbl_FADT.xpm_timer_block.address);
213 /* Disable bus ratio bit */
214 longhaul.bits.EnableSoftBusRatio = 0;
215 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
217 /* Reduce voltage if necessary */
218 if (can_scale_voltage && !dir) {
219 longhaul.bits.EnableSoftVID = 1;
220 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
223 ACPI_FLUSH_CPU_CACHE();
226 ACPI_FLUSH_CPU_CACHE();
229 /* Dummy op - must do something useless after P_LVL3
231 t = inl(acpi_gbl_FADT.xpm_timer_block.address);
233 longhaul.bits.EnableSoftVID = 0;
234 wrmsrl(MSR_VIA_LONGHAUL, longhaul.val);
239 * longhaul_set_cpu_frequency()
240 * @mults_index : bitpattern of the new multiplier.
242 * Sets a new clock ratio.
245 static int longhaul_setstate(struct cpufreq_policy *policy,
246 unsigned int table_index)
248 unsigned int mults_index;
250 struct cpufreq_freqs freqs;
252 unsigned int pic1_mask, pic2_mask;
254 u32 bm_timeout = 1000;
255 unsigned int dir = 0;
257 mults_index = longhaul_table[table_index].driver_data;
258 /* Safety precautions */
259 mult = mults[mults_index & 0x1f];
263 speed = calc_speed(mult);
264 if ((speed > highest_speed) || (speed < lowest_speed))
267 /* Voltage transition before frequency transition? */
268 if (can_scale_voltage && longhaul_index < table_index)
271 freqs.old = calc_speed(longhaul_get_cpu_mult());
274 pr_debug("Setting to FSB:%dMHz Mult:%d.%dx (%s)\n",
275 fsb, mult/10, mult%10, print_speed(speed/1000));
278 local_irq_save(flags);
280 pic2_mask = inb(0xA1);
281 pic1_mask = inb(0x21); /* works on C3. save mask. */
282 outb(0xFF, 0xA1); /* Overkill */
283 outb(0xFE, 0x21); /* TMR0 only */
285 /* Wait while PCI bus is busy. */
286 if (acpi_regs_addr && (longhaul_flags & USE_NORTHBRIDGE
287 || ((pr != NULL) && pr->flags.bm_control))) {
288 bm_status = inw(acpi_regs_addr);
290 while (bm_status && bm_timeout) {
291 outw(1 << 4, acpi_regs_addr);
293 bm_status = inw(acpi_regs_addr);
298 if (longhaul_flags & USE_NORTHBRIDGE) {
299 /* Disable AGP and PCI arbiters */
301 } else if ((pr != NULL) && pr->flags.bm_control) {
302 /* Disable bus master arbitration */
303 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 1);
305 switch (longhaul_version) {
308 * Longhaul v1. (Samuel[C5A] and Samuel2 stepping 0[C5B])
309 * Software controlled multipliers only.
311 case TYPE_LONGHAUL_V1:
312 do_longhaul1(mults_index);
316 * Longhaul v2 appears in Samuel2 Steppings 1->7 [C5B] and Ezra [C5C]
318 * Longhaul v3 (aka Powersaver). (Ezra-T [C5M] & Nehemiah [C5N])
319 * Nehemiah can do FSB scaling too, but this has never been proven
320 * to work in practice.
322 case TYPE_LONGHAUL_V2:
323 case TYPE_POWERSAVER:
324 if (longhaul_flags & USE_ACPI_C3) {
325 /* Don't allow wakeup */
326 acpi_write_bit_register(ACPI_BITREG_BUS_MASTER_RLD, 0);
327 do_powersaver(cx->address, mults_index, dir);
329 do_powersaver(0, mults_index, dir);
334 if (longhaul_flags & USE_NORTHBRIDGE) {
335 /* Enable arbiters */
337 } else if ((pr != NULL) && pr->flags.bm_control) {
338 /* Enable bus master arbitration */
339 acpi_write_bit_register(ACPI_BITREG_ARB_DISABLE, 0);
341 outb(pic2_mask, 0xA1); /* restore mask */
342 outb(pic1_mask, 0x21);
344 local_irq_restore(flags);
347 freqs.new = calc_speed(longhaul_get_cpu_mult());
348 /* Check if requested frequency is set. */
349 if (unlikely(freqs.new != speed)) {
350 pr_info("Failed to set requested frequency!\n");
351 /* Revision ID = 1 but processor is expecting revision key
352 * equal to 0. Jumpers at the bottom of processor will change
353 * multiplier and FSB, but will not change bits in Longhaul
354 * MSR nor enable voltage scaling. */
356 pr_info("Enabling \"Ignore Revision ID\" option\n");
361 /* Why ACPI C3 sometimes doesn't work is a mystery for me.
362 * But it does happen. Processor is entering ACPI C3 state,
363 * but it doesn't change frequency. I tried poking various
364 * bits in northbridge registers, but without success. */
365 if (longhaul_flags & USE_ACPI_C3) {
366 pr_info("Disabling ACPI C3 support\n");
367 longhaul_flags &= ~USE_ACPI_C3;
369 pr_info("Disabling \"Ignore Revision ID\" option\n");
375 /* This shouldn't happen. Longhaul ver. 2 was reported not
376 * working on processors without voltage scaling, but with
377 * RevID = 1. RevID errata will make things right. Just
378 * to be 100% sure. */
379 if (longhaul_version == TYPE_LONGHAUL_V2) {
380 pr_info("Switching to Longhaul ver. 1\n");
381 longhaul_version = TYPE_LONGHAUL_V1;
388 pr_info("Warning: Timeout while waiting for idle PCI bus\n");
396 * Centaur decided to make life a little more tricky.
397 * Only longhaul v1 is allowed to read EBLCR BSEL[0:1].
398 * Samuel2 and above have to try and guess what the FSB is.
399 * We do this by assuming we booted at maximum multiplier, and interpolate
400 * between that value multiplied by possible FSBs and cpu_mhz which
401 * was calculated at boot time. Really ugly, but no other way to do this.
406 static int guess_fsb(int mult)
408 int speed = cpu_khz / 1000;
410 int speeds[] = { 666, 1000, 1333, 2000 };
413 for (i = 0; i < 4; i++) {
414 f_max = ((speeds[i] * mult) + 50) / 100;
415 f_max += (ROUNDING / 2);
416 f_min = f_max - ROUNDING;
417 if ((speed <= f_max) && (speed >= f_min))
418 return speeds[i] / 10;
424 static int longhaul_get_ranges(void)
426 unsigned int i, j, k = 0;
430 /* Get current frequency */
431 mult = longhaul_get_cpu_mult();
433 pr_info("Invalid (reserved) multiplier!\n");
436 fsb = guess_fsb(mult);
438 pr_info("Invalid (reserved) FSB!\n");
441 /* Get max multiplier - as we always did.
442 * Longhaul MSR is useful only when voltage scaling is enabled.
443 * C3 is booting at max anyway. */
445 /* Get min multiplier */
458 pr_debug("MinMult:%d.%dx MaxMult:%d.%dx\n",
459 minmult/10, minmult%10, maxmult/10, maxmult%10);
461 highest_speed = calc_speed(maxmult);
462 lowest_speed = calc_speed(minmult);
463 pr_debug("FSB:%dMHz Lowest speed: %s Highest speed:%s\n", fsb,
464 print_speed(lowest_speed/1000),
465 print_speed(highest_speed/1000));
467 if (lowest_speed == highest_speed) {
468 pr_info("highestspeed == lowest, aborting\n");
471 if (lowest_speed > highest_speed) {
472 pr_info("nonsense! lowest (%d > %d) !\n",
473 lowest_speed, highest_speed);
477 longhaul_table = kcalloc(numscales + 1, sizeof(*longhaul_table),
482 for (j = 0; j < numscales; j++) {
486 if (ratio > maxmult || ratio < minmult)
488 longhaul_table[k].frequency = calc_speed(ratio);
489 longhaul_table[k].driver_data = j;
493 kfree(longhaul_table);
497 for (j = 0; j < k - 1; j++) {
498 unsigned int min_f, min_i;
499 min_f = longhaul_table[j].frequency;
501 for (i = j + 1; i < k; i++) {
502 if (longhaul_table[i].frequency < min_f) {
503 min_f = longhaul_table[i].frequency;
508 swap(longhaul_table[j].frequency,
509 longhaul_table[min_i].frequency);
510 swap(longhaul_table[j].driver_data,
511 longhaul_table[min_i].driver_data);
515 longhaul_table[k].frequency = CPUFREQ_TABLE_END;
517 /* Find index we are running on */
518 for (j = 0; j < k; j++) {
519 if (mults[longhaul_table[j].driver_data & 0x1f] == mult) {
528 static void longhaul_setup_voltagescaling(void)
530 struct cpufreq_frequency_table *freq_pos;
531 union msr_longhaul longhaul;
532 struct mV_pos minvid, maxvid, vid;
533 unsigned int j, speed, pos, kHz_step, numvscales;
536 rdmsrl(MSR_VIA_LONGHAUL, longhaul.val);
537 if (!(longhaul.bits.RevisionID & 1)) {
538 pr_info("Voltage scaling not supported by CPU\n");
542 if (!longhaul.bits.VRMRev) {
543 pr_info("VRM 8.5\n");
544 vrm_mV_table = &vrm85_mV[0];
545 mV_vrm_table = &mV_vrm85[0];
547 pr_info("Mobile VRM\n");
548 if (cpu_model < CPU_NEHEMIAH)
550 vrm_mV_table = &mobilevrm_mV[0];
551 mV_vrm_table = &mV_mobilevrm[0];
554 minvid = vrm_mV_table[longhaul.bits.MinimumVID];
555 maxvid = vrm_mV_table[longhaul.bits.MaximumVID];
557 if (minvid.mV == 0 || maxvid.mV == 0 || minvid.mV > maxvid.mV) {
558 pr_info("Bogus values Min:%d.%03d Max:%d.%03d - Voltage scaling disabled\n",
559 minvid.mV/1000, minvid.mV%1000,
560 maxvid.mV/1000, maxvid.mV%1000);
564 if (minvid.mV == maxvid.mV) {
565 pr_info("Claims to support voltage scaling but min & max are both %d.%03d - Voltage scaling disabled\n",
566 maxvid.mV/1000, maxvid.mV%1000);
570 /* How many voltage steps*/
571 numvscales = maxvid.pos - minvid.pos + 1;
572 pr_info("Max VID=%d.%03d Min VID=%d.%03d, %d possible voltage scales\n",
573 maxvid.mV/1000, maxvid.mV%1000,
574 minvid.mV/1000, minvid.mV%1000,
577 /* Calculate max frequency at min voltage */
578 j = longhaul.bits.MinMHzBR;
579 if (longhaul.bits.MinMHzBR4)
581 min_vid_speed = eblcr[j];
582 if (min_vid_speed == -1)
584 switch (longhaul.bits.MinMHzFSB) {
586 min_vid_speed *= 13333;
589 min_vid_speed *= 10000;
592 min_vid_speed *= 6666;
598 if (min_vid_speed >= highest_speed)
600 /* Calculate kHz for one voltage step */
601 kHz_step = (highest_speed - min_vid_speed) / numvscales;
603 cpufreq_for_each_entry_idx(freq_pos, longhaul_table, j) {
604 speed = freq_pos->frequency;
605 if (speed > min_vid_speed)
606 pos = (speed - min_vid_speed) / kHz_step + minvid.pos;
609 freq_pos->driver_data |= mV_vrm_table[pos] << 8;
610 vid = vrm_mV_table[mV_vrm_table[pos]];
611 pr_info("f: %d kHz, index: %d, vid: %d mV\n",
615 can_scale_voltage = 1;
616 pr_info("Voltage scaling enabled\n");
620 static int longhaul_target(struct cpufreq_policy *policy,
621 unsigned int table_index)
624 unsigned int dir = 0;
628 if (!can_scale_voltage)
629 retval = longhaul_setstate(policy, table_index);
631 /* On test system voltage transitions exceeding single
632 * step up or down were turning motherboard off. Both
633 * "ondemand" and "userspace" are unsafe. C7 is doing
634 * this in hardware, C3 is old and we need to do this
637 current_vid = (longhaul_table[longhaul_index].driver_data >> 8);
639 if (table_index > longhaul_index)
641 while (i != table_index) {
642 vid = (longhaul_table[i].driver_data >> 8) & 0x1f;
643 if (vid != current_vid) {
644 retval = longhaul_setstate(policy, i);
653 retval = longhaul_setstate(policy, table_index);
656 longhaul_index = table_index;
661 static unsigned int longhaul_get(unsigned int cpu)
665 return calc_speed(longhaul_get_cpu_mult());
668 static acpi_status longhaul_walk_callback(acpi_handle obj_handle,
670 void *context, void **return_value)
672 struct acpi_device *d;
674 if (acpi_bus_get_device(obj_handle, &d))
677 *return_value = acpi_driver_data(d);
681 /* VIA don't support PM2 reg, but have something similar */
682 static int enable_arbiter_disable(void)
689 /* Find PLE133 host bridge */
691 dev = pci_get_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8601_0,
693 /* Find PM133/VT8605 host bridge */
695 dev = pci_get_device(PCI_VENDOR_ID_VIA,
696 PCI_DEVICE_ID_VIA_8605_0, NULL);
697 /* Find CLE266 host bridge */
700 dev = pci_get_device(PCI_VENDOR_ID_VIA,
701 PCI_DEVICE_ID_VIA_862X_0, NULL);
702 /* Find CN400 V-Link host bridge */
704 dev = pci_get_device(PCI_VENDOR_ID_VIA, 0x7259, NULL);
707 /* Enable access to port 0x22 */
708 pci_read_config_byte(dev, reg, &pci_cmd);
709 if (!(pci_cmd & 1<<7)) {
711 pci_write_config_byte(dev, reg, pci_cmd);
712 pci_read_config_byte(dev, reg, &pci_cmd);
713 if (!(pci_cmd & 1<<7)) {
714 pr_err("Can't enable access to port 0x22\n");
724 static int longhaul_setup_southbridge(void)
729 /* Find VT8235 southbridge */
730 dev = pci_get_device(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_8235, NULL);
732 /* Find VT8237 southbridge */
733 dev = pci_get_device(PCI_VENDOR_ID_VIA,
734 PCI_DEVICE_ID_VIA_8237, NULL);
736 /* Set transition time to max */
737 pci_read_config_byte(dev, 0xec, &pci_cmd);
738 pci_cmd &= ~(1 << 2);
739 pci_write_config_byte(dev, 0xec, pci_cmd);
740 pci_read_config_byte(dev, 0xe4, &pci_cmd);
741 pci_cmd &= ~(1 << 7);
742 pci_write_config_byte(dev, 0xe4, pci_cmd);
743 pci_read_config_byte(dev, 0xe5, &pci_cmd);
745 pci_write_config_byte(dev, 0xe5, pci_cmd);
746 /* Get address of ACPI registers block*/
747 pci_read_config_byte(dev, 0x81, &pci_cmd);
748 if (pci_cmd & 1 << 7) {
749 pci_read_config_dword(dev, 0x88, &acpi_regs_addr);
750 acpi_regs_addr &= 0xff00;
751 pr_info("ACPI I/O at 0x%x\n", acpi_regs_addr);
760 static int longhaul_cpu_init(struct cpufreq_policy *policy)
762 struct cpuinfo_x86 *c = &cpu_data(0);
763 char *cpuname = NULL;
767 /* Check what we have on this motherboard */
768 switch (c->x86_model) {
770 cpu_model = CPU_SAMUEL;
771 cpuname = "C3 'Samuel' [C5A]";
772 longhaul_version = TYPE_LONGHAUL_V1;
773 memcpy(mults, samuel1_mults, sizeof(samuel1_mults));
774 memcpy(eblcr, samuel1_eblcr, sizeof(samuel1_eblcr));
778 switch (c->x86_stepping) {
780 longhaul_version = TYPE_LONGHAUL_V1;
781 cpu_model = CPU_SAMUEL2;
782 cpuname = "C3 'Samuel 2' [C5B]";
783 /* Note, this is not a typo, early Samuel2's had
785 memcpy(mults, samuel1_mults, sizeof(samuel1_mults));
786 memcpy(eblcr, samuel2_eblcr, sizeof(samuel2_eblcr));
789 longhaul_version = TYPE_LONGHAUL_V2;
790 if (c->x86_stepping < 8) {
791 cpu_model = CPU_SAMUEL2;
792 cpuname = "C3 'Samuel 2' [C5B]";
794 cpu_model = CPU_EZRA;
795 cpuname = "C3 'Ezra' [C5C]";
797 memcpy(mults, ezra_mults, sizeof(ezra_mults));
798 memcpy(eblcr, ezra_eblcr, sizeof(ezra_eblcr));
804 cpu_model = CPU_EZRA_T;
805 cpuname = "C3 'Ezra-T' [C5M]";
806 longhaul_version = TYPE_POWERSAVER;
808 memcpy(mults, ezrat_mults, sizeof(ezrat_mults));
809 memcpy(eblcr, ezrat_eblcr, sizeof(ezrat_eblcr));
813 longhaul_version = TYPE_POWERSAVER;
815 memcpy(mults, nehemiah_mults, sizeof(nehemiah_mults));
816 memcpy(eblcr, nehemiah_eblcr, sizeof(nehemiah_eblcr));
817 switch (c->x86_stepping) {
819 cpu_model = CPU_NEHEMIAH;
820 cpuname = "C3 'Nehemiah A' [C5XLOE]";
823 cpu_model = CPU_NEHEMIAH;
824 cpuname = "C3 'Nehemiah B' [C5XLOH]";
827 cpu_model = CPU_NEHEMIAH_C;
828 cpuname = "C3 'Nehemiah C' [C5P]";
837 /* Check Longhaul ver. 2 */
838 if (longhaul_version == TYPE_LONGHAUL_V2) {
839 rdmsr(MSR_VIA_LONGHAUL, lo, hi);
840 if (lo == 0 && hi == 0)
841 /* Looks like MSR isn't present */
842 longhaul_version = TYPE_LONGHAUL_V1;
845 pr_info("VIA %s CPU detected. ", cpuname);
846 switch (longhaul_version) {
847 case TYPE_LONGHAUL_V1:
848 case TYPE_LONGHAUL_V2:
849 pr_cont("Longhaul v%d supported\n", longhaul_version);
851 case TYPE_POWERSAVER:
852 pr_cont("Powersaver supported\n");
857 longhaul_setup_southbridge();
859 /* Find ACPI data for processor */
860 acpi_walk_namespace(ACPI_TYPE_PROCESSOR, ACPI_ROOT_OBJECT,
861 ACPI_UINT32_MAX, &longhaul_walk_callback, NULL,
864 /* Check ACPI support for C3 state */
865 if (pr != NULL && longhaul_version == TYPE_POWERSAVER) {
866 cx = &pr->power.states[ACPI_STATE_C3];
867 if (cx->address > 0 && cx->latency <= 1000)
868 longhaul_flags |= USE_ACPI_C3;
870 /* Disable if it isn't working */
872 longhaul_flags &= ~USE_ACPI_C3;
873 /* Check if northbridge is friendly */
874 if (enable_arbiter_disable())
875 longhaul_flags |= USE_NORTHBRIDGE;
877 /* Check ACPI support for bus master arbiter disable */
878 if (!(longhaul_flags & USE_ACPI_C3
879 || longhaul_flags & USE_NORTHBRIDGE)
880 && ((pr == NULL) || !(pr->flags.bm_control))) {
881 pr_err("No ACPI support: Unsupported northbridge\n");
885 if (longhaul_flags & USE_NORTHBRIDGE)
886 pr_info("Using northbridge support\n");
887 if (longhaul_flags & USE_ACPI_C3)
888 pr_info("Using ACPI support\n");
890 ret = longhaul_get_ranges();
894 if ((longhaul_version != TYPE_LONGHAUL_V1) && (scale_voltage != 0))
895 longhaul_setup_voltagescaling();
897 policy->transition_delay_us = 200000; /* usec */
898 policy->freq_table = longhaul_table;
903 static struct cpufreq_driver longhaul_driver = {
904 .verify = cpufreq_generic_frequency_table_verify,
905 .target_index = longhaul_target,
907 .init = longhaul_cpu_init,
909 .attr = cpufreq_generic_attr,
912 static const struct x86_cpu_id longhaul_id[] = {
913 { X86_VENDOR_CENTAUR, 6 },
916 MODULE_DEVICE_TABLE(x86cpu, longhaul_id);
918 static int __init longhaul_init(void)
920 struct cpuinfo_x86 *c = &cpu_data(0);
922 if (!x86_match_cpu(longhaul_id))
926 pr_err("Option \"enable\" not set - Aborting\n");
930 if (num_online_cpus() > 1) {
931 pr_err("More than 1 CPU detected, longhaul disabled\n");
935 #ifdef CONFIG_X86_IO_APIC
936 if (boot_cpu_has(X86_FEATURE_APIC)) {
937 pr_err("APIC detected. Longhaul is currently broken in this configuration.\n");
941 switch (c->x86_model) {
943 return cpufreq_register_driver(&longhaul_driver);
945 pr_err("Use acpi-cpufreq driver for VIA C7\n");
954 static void __exit longhaul_exit(void)
956 struct cpufreq_policy *policy = cpufreq_cpu_get(0);
959 for (i = 0; i < numscales; i++) {
960 if (mults[i] == maxmult) {
961 struct cpufreq_freqs freqs;
963 freqs.old = policy->cur;
964 freqs.new = longhaul_table[i].frequency;
967 cpufreq_freq_transition_begin(policy, &freqs);
968 longhaul_setstate(policy, i);
969 cpufreq_freq_transition_end(policy, &freqs, 0);
974 cpufreq_cpu_put(policy);
975 cpufreq_unregister_driver(&longhaul_driver);
976 kfree(longhaul_table);
979 /* Even if BIOS is exporting ACPI C3 state, and it is used
980 * with success when CPU is idle, this state doesn't
981 * trigger frequency transition in some cases. */
982 module_param(disable_acpi_c3, int, 0644);
983 MODULE_PARM_DESC(disable_acpi_c3, "Don't use ACPI C3 support");
984 /* Change CPU voltage with frequency. Very useful to save
985 * power, but most VIA C3 processors aren't supporting it. */
986 module_param(scale_voltage, int, 0644);
987 MODULE_PARM_DESC(scale_voltage, "Scale voltage of processor");
988 /* Force revision key to 0 for processors which doesn't
989 * support voltage scaling, but are introducing itself as
991 module_param(revid_errata, int, 0644);
992 MODULE_PARM_DESC(revid_errata, "Ignore CPU Revision ID");
993 /* By default driver is disabled to prevent incompatible
995 module_param(enable, int, 0644);
996 MODULE_PARM_DESC(enable, "Enable driver");
998 MODULE_AUTHOR("Dave Jones");
999 MODULE_DESCRIPTION("Longhaul driver for VIA Cyrix processors.");
1000 MODULE_LICENSE("GPL");
1002 late_initcall(longhaul_init);
1003 module_exit(longhaul_exit);