init from v2.6.32.60
[mach-moxart.git] / arch / x86 / kernel / cpu / cpufreq / powernow-k8.c
blob5e92606c4cf8ecc58a8396549b5f6c3198bdd69d
2 /*
3 * (c) 2003-2006 Advanced Micro Devices, Inc.
4 * Your use of this code is subject to the terms and conditions of the
5 * GNU general public license version 2. See "COPYING" or
6 * http://www.gnu.org/licenses/gpl.html
8 * Support : mark.langsdorf@amd.com
10 * Based on the powernow-k7.c module written by Dave Jones.
11 * (C) 2003 Dave Jones on behalf of SuSE Labs
12 * (C) 2004 Dominik Brodowski <linux@brodo.de>
13 * (C) 2004 Pavel Machek <pavel@suse.cz>
14 * Licensed under the terms of the GNU GPL License version 2.
15 * Based upon datasheets & sample CPUs kindly provided by AMD.
17 * Valuable input gratefully received from Dave Jones, Pavel Machek,
18 * Dominik Brodowski, Jacob Shin, and others.
19 * Originally developed by Paul Devriendt.
20 * Processor information obtained from Chapter 9 (Power and Thermal Management)
21 * of the "BIOS and Kernel Developer's Guide for the AMD Athlon 64 and AMD
22 * Opteron Processors" available for download from www.amd.com
24 * Tables for specific CPUs can be inferred from
25 * http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf
28 #include <linux/kernel.h>
29 #include <linux/smp.h>
30 #include <linux/module.h>
31 #include <linux/init.h>
32 #include <linux/cpufreq.h>
33 #include <linux/slab.h>
34 #include <linux/string.h>
35 #include <linux/cpumask.h>
36 #include <linux/sched.h> /* for current / set_cpus_allowed() */
37 #include <linux/io.h>
38 #include <linux/delay.h>
40 #include <asm/msr.h>
42 #include <linux/acpi.h>
43 #include <linux/mutex.h>
44 #include <acpi/processor.h>
46 #define PFX "powernow-k8: "
47 #define VERSION "version 2.20.00"
48 #include "powernow-k8.h"
50 /* serialize freq changes */
51 static DEFINE_MUTEX(fidvid_mutex);
53 static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
55 static int cpu_family = CPU_OPTERON;
57 #ifndef CONFIG_SMP
58 static inline const struct cpumask *cpu_core_mask(int cpu)
60 return cpumask_of(0);
62 #endif
64 /* Return a frequency in MHz, given an input fid */
65 static u32 find_freq_from_fid(u32 fid)
67 return 800 + (fid * 100);
70 /* Return a frequency in KHz, given an input fid */
71 static u32 find_khz_freq_from_fid(u32 fid)
73 return 1000 * find_freq_from_fid(fid);
76 static u32 find_khz_freq_from_pstate(struct cpufreq_frequency_table *data,
77 u32 pstate)
79 return data[pstate].frequency;
82 /* Return the vco fid for an input fid
84 * Each "low" fid has corresponding "high" fid, and you can get to "low" fids
85 * only from corresponding high fids. This returns "high" fid corresponding to
86 * "low" one.
88 static u32 convert_fid_to_vco_fid(u32 fid)
90 if (fid < HI_FID_TABLE_BOTTOM)
91 return 8 + (2 * fid);
92 else
93 return fid;
97 * Return 1 if the pending bit is set. Unless we just instructed the processor
98 * to transition to a new state, seeing this bit set is really bad news.
100 static int pending_bit_stuck(void)
102 u32 lo, hi;
104 if (cpu_family == CPU_HW_PSTATE)
105 return 0;
107 rdmsr(MSR_FIDVID_STATUS, lo, hi);
108 return lo & MSR_S_LO_CHANGE_PENDING ? 1 : 0;
112 * Update the global current fid / vid values from the status msr.
113 * Returns 1 on error.
115 static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
117 u32 lo, hi;
118 u32 i = 0;
120 if (cpu_family == CPU_HW_PSTATE) {
121 rdmsr(MSR_PSTATE_STATUS, lo, hi);
122 i = lo & HW_PSTATE_MASK;
123 data->currpstate = i;
126 * a workaround for family 11h erratum 311 might cause
127 * an "out-of-range Pstate if the core is in Pstate-0
129 if ((boot_cpu_data.x86 == 0x11) && (i >= data->numps))
130 data->currpstate = HW_PSTATE_0;
132 return 0;
134 do {
135 if (i++ > 10000) {
136 dprintk("detected change pending stuck\n");
137 return 1;
139 rdmsr(MSR_FIDVID_STATUS, lo, hi);
140 } while (lo & MSR_S_LO_CHANGE_PENDING);
142 data->currvid = hi & MSR_S_HI_CURRENT_VID;
143 data->currfid = lo & MSR_S_LO_CURRENT_FID;
145 return 0;
148 /* the isochronous relief time */
149 static void count_off_irt(struct powernow_k8_data *data)
151 udelay((1 << data->irt) * 10);
152 return;
155 /* the voltage stabilization time */
156 static void count_off_vst(struct powernow_k8_data *data)
158 udelay(data->vstable * VST_UNITS_20US);
159 return;
162 /* need to init the control msr to a safe value (for each cpu) */
163 static void fidvid_msr_init(void)
165 u32 lo, hi;
166 u8 fid, vid;
168 rdmsr(MSR_FIDVID_STATUS, lo, hi);
169 vid = hi & MSR_S_HI_CURRENT_VID;
170 fid = lo & MSR_S_LO_CURRENT_FID;
171 lo = fid | (vid << MSR_C_LO_VID_SHIFT);
172 hi = MSR_C_HI_STP_GNT_BENIGN;
173 dprintk("cpu%d, init lo 0x%x, hi 0x%x\n", smp_processor_id(), lo, hi);
174 wrmsr(MSR_FIDVID_CTL, lo, hi);
177 /* write the new fid value along with the other control fields to the msr */
178 static int write_new_fid(struct powernow_k8_data *data, u32 fid)
180 u32 lo;
181 u32 savevid = data->currvid;
182 u32 i = 0;
184 if ((fid & INVALID_FID_MASK) || (data->currvid & INVALID_VID_MASK)) {
185 printk(KERN_ERR PFX "internal error - overflow on fid write\n");
186 return 1;
189 lo = fid;
190 lo |= (data->currvid << MSR_C_LO_VID_SHIFT);
191 lo |= MSR_C_LO_INIT_FID_VID;
193 dprintk("writing fid 0x%x, lo 0x%x, hi 0x%x\n",
194 fid, lo, data->plllock * PLL_LOCK_CONVERSION);
196 do {
197 wrmsr(MSR_FIDVID_CTL, lo, data->plllock * PLL_LOCK_CONVERSION);
198 if (i++ > 100) {
199 printk(KERN_ERR PFX
200 "Hardware error - pending bit very stuck - "
201 "no further pstate changes possible\n");
202 return 1;
204 } while (query_current_values_with_pending_wait(data));
206 count_off_irt(data);
208 if (savevid != data->currvid) {
209 printk(KERN_ERR PFX
210 "vid change on fid trans, old 0x%x, new 0x%x\n",
211 savevid, data->currvid);
212 return 1;
215 if (fid != data->currfid) {
216 printk(KERN_ERR PFX
217 "fid trans failed, fid 0x%x, curr 0x%x\n", fid,
218 data->currfid);
219 return 1;
222 return 0;
225 /* Write a new vid to the hardware */
226 static int write_new_vid(struct powernow_k8_data *data, u32 vid)
228 u32 lo;
229 u32 savefid = data->currfid;
230 int i = 0;
232 if ((data->currfid & INVALID_FID_MASK) || (vid & INVALID_VID_MASK)) {
233 printk(KERN_ERR PFX "internal error - overflow on vid write\n");
234 return 1;
237 lo = data->currfid;
238 lo |= (vid << MSR_C_LO_VID_SHIFT);
239 lo |= MSR_C_LO_INIT_FID_VID;
241 dprintk("writing vid 0x%x, lo 0x%x, hi 0x%x\n",
242 vid, lo, STOP_GRANT_5NS);
244 do {
245 wrmsr(MSR_FIDVID_CTL, lo, STOP_GRANT_5NS);
246 if (i++ > 100) {
247 printk(KERN_ERR PFX "internal error - pending bit "
248 "very stuck - no further pstate "
249 "changes possible\n");
250 return 1;
252 } while (query_current_values_with_pending_wait(data));
254 if (savefid != data->currfid) {
255 printk(KERN_ERR PFX "fid changed on vid trans, old "
256 "0x%x new 0x%x\n",
257 savefid, data->currfid);
258 return 1;
261 if (vid != data->currvid) {
262 printk(KERN_ERR PFX "vid trans failed, vid 0x%x, "
263 "curr 0x%x\n",
264 vid, data->currvid);
265 return 1;
268 return 0;
272 * Reduce the vid by the max of step or reqvid.
273 * Decreasing vid codes represent increasing voltages:
274 * vid of 0 is 1.550V, vid of 0x1e is 0.800V, vid of VID_OFF is off.
276 static int decrease_vid_code_by_step(struct powernow_k8_data *data,
277 u32 reqvid, u32 step)
279 if ((data->currvid - reqvid) > step)
280 reqvid = data->currvid - step;
282 if (write_new_vid(data, reqvid))
283 return 1;
285 count_off_vst(data);
287 return 0;
290 /* Change hardware pstate by single MSR write */
291 static int transition_pstate(struct powernow_k8_data *data, u32 pstate)
293 wrmsr(MSR_PSTATE_CTRL, pstate, 0);
294 data->currpstate = pstate;
295 return 0;
298 /* Change Opteron/Athlon64 fid and vid, by the 3 phases. */
299 static int transition_fid_vid(struct powernow_k8_data *data,
300 u32 reqfid, u32 reqvid)
302 if (core_voltage_pre_transition(data, reqvid, reqfid))
303 return 1;
305 if (core_frequency_transition(data, reqfid))
306 return 1;
308 if (core_voltage_post_transition(data, reqvid))
309 return 1;
311 if (query_current_values_with_pending_wait(data))
312 return 1;
314 if ((reqfid != data->currfid) || (reqvid != data->currvid)) {
315 printk(KERN_ERR PFX "failed (cpu%d): req 0x%x 0x%x, "
316 "curr 0x%x 0x%x\n",
317 smp_processor_id(),
318 reqfid, reqvid, data->currfid, data->currvid);
319 return 1;
322 dprintk("transitioned (cpu%d): new fid 0x%x, vid 0x%x\n",
323 smp_processor_id(), data->currfid, data->currvid);
325 return 0;
328 /* Phase 1 - core voltage transition ... setup voltage */
329 static int core_voltage_pre_transition(struct powernow_k8_data *data,
330 u32 reqvid, u32 reqfid)
332 u32 rvosteps = data->rvo;
333 u32 savefid = data->currfid;
334 u32 maxvid, lo, rvomult = 1;
336 dprintk("ph1 (cpu%d): start, currfid 0x%x, currvid 0x%x, "
337 "reqvid 0x%x, rvo 0x%x\n",
338 smp_processor_id(),
339 data->currfid, data->currvid, reqvid, data->rvo);
341 if ((savefid < LO_FID_TABLE_TOP) && (reqfid < LO_FID_TABLE_TOP))
342 rvomult = 2;
343 rvosteps *= rvomult;
344 rdmsr(MSR_FIDVID_STATUS, lo, maxvid);
345 maxvid = 0x1f & (maxvid >> 16);
346 dprintk("ph1 maxvid=0x%x\n", maxvid);
347 if (reqvid < maxvid) /* lower numbers are higher voltages */
348 reqvid = maxvid;
350 while (data->currvid > reqvid) {
351 dprintk("ph1: curr 0x%x, req vid 0x%x\n",
352 data->currvid, reqvid);
353 if (decrease_vid_code_by_step(data, reqvid, data->vidmvs))
354 return 1;
357 while ((rvosteps > 0) &&
358 ((rvomult * data->rvo + data->currvid) > reqvid)) {
359 if (data->currvid == maxvid) {
360 rvosteps = 0;
361 } else {
362 dprintk("ph1: changing vid for rvo, req 0x%x\n",
363 data->currvid - 1);
364 if (decrease_vid_code_by_step(data, data->currvid-1, 1))
365 return 1;
366 rvosteps--;
370 if (query_current_values_with_pending_wait(data))
371 return 1;
373 if (savefid != data->currfid) {
374 printk(KERN_ERR PFX "ph1 err, currfid changed 0x%x\n",
375 data->currfid);
376 return 1;
379 dprintk("ph1 complete, currfid 0x%x, currvid 0x%x\n",
380 data->currfid, data->currvid);
382 return 0;
385 /* Phase 2 - core frequency transition */
386 static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid)
388 u32 vcoreqfid, vcocurrfid, vcofiddiff;
389 u32 fid_interval, savevid = data->currvid;
391 if (data->currfid == reqfid) {
392 printk(KERN_ERR PFX "ph2 null fid transition 0x%x\n",
393 data->currfid);
394 return 0;
397 dprintk("ph2 (cpu%d): starting, currfid 0x%x, currvid 0x%x, "
398 "reqfid 0x%x\n",
399 smp_processor_id(),
400 data->currfid, data->currvid, reqfid);
402 vcoreqfid = convert_fid_to_vco_fid(reqfid);
403 vcocurrfid = convert_fid_to_vco_fid(data->currfid);
404 vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
405 : vcoreqfid - vcocurrfid;
407 if ((reqfid <= LO_FID_TABLE_TOP) && (data->currfid <= LO_FID_TABLE_TOP))
408 vcofiddiff = 0;
410 while (vcofiddiff > 2) {
411 (data->currfid & 1) ? (fid_interval = 1) : (fid_interval = 2);
413 if (reqfid > data->currfid) {
414 if (data->currfid > LO_FID_TABLE_TOP) {
415 if (write_new_fid(data,
416 data->currfid + fid_interval))
417 return 1;
418 } else {
419 if (write_new_fid
420 (data,
421 2 + convert_fid_to_vco_fid(data->currfid)))
422 return 1;
424 } else {
425 if (write_new_fid(data, data->currfid - fid_interval))
426 return 1;
429 vcocurrfid = convert_fid_to_vco_fid(data->currfid);
430 vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
431 : vcoreqfid - vcocurrfid;
434 if (write_new_fid(data, reqfid))
435 return 1;
437 if (query_current_values_with_pending_wait(data))
438 return 1;
440 if (data->currfid != reqfid) {
441 printk(KERN_ERR PFX
442 "ph2: mismatch, failed fid transition, "
443 "curr 0x%x, req 0x%x\n",
444 data->currfid, reqfid);
445 return 1;
448 if (savevid != data->currvid) {
449 printk(KERN_ERR PFX "ph2: vid changed, save 0x%x, curr 0x%x\n",
450 savevid, data->currvid);
451 return 1;
454 dprintk("ph2 complete, currfid 0x%x, currvid 0x%x\n",
455 data->currfid, data->currvid);
457 return 0;
460 /* Phase 3 - core voltage transition flow ... jump to the final vid. */
461 static int core_voltage_post_transition(struct powernow_k8_data *data,
462 u32 reqvid)
464 u32 savefid = data->currfid;
465 u32 savereqvid = reqvid;
467 dprintk("ph3 (cpu%d): starting, currfid 0x%x, currvid 0x%x\n",
468 smp_processor_id(),
469 data->currfid, data->currvid);
471 if (reqvid != data->currvid) {
472 if (write_new_vid(data, reqvid))
473 return 1;
475 if (savefid != data->currfid) {
476 printk(KERN_ERR PFX
477 "ph3: bad fid change, save 0x%x, curr 0x%x\n",
478 savefid, data->currfid);
479 return 1;
482 if (data->currvid != reqvid) {
483 printk(KERN_ERR PFX
484 "ph3: failed vid transition\n, "
485 "req 0x%x, curr 0x%x",
486 reqvid, data->currvid);
487 return 1;
491 if (query_current_values_with_pending_wait(data))
492 return 1;
494 if (savereqvid != data->currvid) {
495 dprintk("ph3 failed, currvid 0x%x\n", data->currvid);
496 return 1;
499 if (savefid != data->currfid) {
500 dprintk("ph3 failed, currfid changed 0x%x\n",
501 data->currfid);
502 return 1;
505 dprintk("ph3 complete, currfid 0x%x, currvid 0x%x\n",
506 data->currfid, data->currvid);
508 return 0;
511 static void check_supported_cpu(void *_rc)
513 u32 eax, ebx, ecx, edx;
514 int *rc = _rc;
516 *rc = -ENODEV;
518 if (current_cpu_data.x86_vendor != X86_VENDOR_AMD)
519 return;
521 eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
522 if (((eax & CPUID_XFAM) != CPUID_XFAM_K8) &&
523 ((eax & CPUID_XFAM) < CPUID_XFAM_10H))
524 return;
526 if ((eax & CPUID_XFAM) == CPUID_XFAM_K8) {
527 if (((eax & CPUID_USE_XFAM_XMOD) != CPUID_USE_XFAM_XMOD) ||
528 ((eax & CPUID_XMOD) > CPUID_XMOD_REV_MASK)) {
529 printk(KERN_INFO PFX
530 "Processor cpuid %x not supported\n", eax);
531 return;
534 eax = cpuid_eax(CPUID_GET_MAX_CAPABILITIES);
535 if (eax < CPUID_FREQ_VOLT_CAPABILITIES) {
536 printk(KERN_INFO PFX
537 "No frequency change capabilities detected\n");
538 return;
541 cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
542 if ((edx & P_STATE_TRANSITION_CAPABLE)
543 != P_STATE_TRANSITION_CAPABLE) {
544 printk(KERN_INFO PFX
545 "Power state transitions not supported\n");
546 return;
548 } else { /* must be a HW Pstate capable processor */
549 cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
550 if ((edx & USE_HW_PSTATE) == USE_HW_PSTATE)
551 cpu_family = CPU_HW_PSTATE;
552 else
553 return;
556 *rc = 0;
559 static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst,
560 u8 maxvid)
562 unsigned int j;
563 u8 lastfid = 0xff;
565 for (j = 0; j < data->numps; j++) {
566 if (pst[j].vid > LEAST_VID) {
567 printk(KERN_ERR FW_BUG PFX "vid %d invalid : 0x%x\n",
568 j, pst[j].vid);
569 return -EINVAL;
571 if (pst[j].vid < data->rvo) {
572 /* vid + rvo >= 0 */
573 printk(KERN_ERR FW_BUG PFX "0 vid exceeded with pstate"
574 " %d\n", j);
575 return -ENODEV;
577 if (pst[j].vid < maxvid + data->rvo) {
578 /* vid + rvo >= maxvid */
579 printk(KERN_ERR FW_BUG PFX "maxvid exceeded with pstate"
580 " %d\n", j);
581 return -ENODEV;
583 if (pst[j].fid > MAX_FID) {
584 printk(KERN_ERR FW_BUG PFX "maxfid exceeded with pstate"
585 " %d\n", j);
586 return -ENODEV;
588 if (j && (pst[j].fid < HI_FID_TABLE_BOTTOM)) {
589 /* Only first fid is allowed to be in "low" range */
590 printk(KERN_ERR FW_BUG PFX "two low fids - %d : "
591 "0x%x\n", j, pst[j].fid);
592 return -EINVAL;
594 if (pst[j].fid < lastfid)
595 lastfid = pst[j].fid;
597 if (lastfid & 1) {
598 printk(KERN_ERR FW_BUG PFX "lastfid invalid\n");
599 return -EINVAL;
601 if (lastfid > LO_FID_TABLE_TOP)
602 printk(KERN_INFO FW_BUG PFX
603 "first fid not from lo freq table\n");
605 return 0;
608 static void invalidate_entry(struct cpufreq_frequency_table *powernow_table,
609 unsigned int entry)
611 powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
614 static void print_basics(struct powernow_k8_data *data)
616 int j;
617 for (j = 0; j < data->numps; j++) {
618 if (data->powernow_table[j].frequency !=
619 CPUFREQ_ENTRY_INVALID) {
620 if (cpu_family == CPU_HW_PSTATE) {
621 printk(KERN_INFO PFX
622 " %d : pstate %d (%d MHz)\n", j,
623 data->powernow_table[j].index,
624 data->powernow_table[j].frequency/1000);
625 } else {
626 printk(KERN_INFO PFX
627 " %d : fid 0x%x (%d MHz), vid 0x%x\n",
629 data->powernow_table[j].index & 0xff,
630 data->powernow_table[j].frequency/1000,
631 data->powernow_table[j].index >> 8);
635 if (data->batps)
636 printk(KERN_INFO PFX "Only %d pstates on battery\n",
637 data->batps);
640 static u32 freq_from_fid_did(u32 fid, u32 did)
642 u32 mhz = 0;
644 if (boot_cpu_data.x86 == 0x10)
645 mhz = (100 * (fid + 0x10)) >> did;
646 else if (boot_cpu_data.x86 == 0x11)
647 mhz = (100 * (fid + 8)) >> did;
648 else
649 BUG();
651 return mhz * 1000;
654 static int fill_powernow_table(struct powernow_k8_data *data,
655 struct pst_s *pst, u8 maxvid)
657 struct cpufreq_frequency_table *powernow_table;
658 unsigned int j;
660 if (data->batps) {
661 /* use ACPI support to get full speed on mains power */
662 printk(KERN_WARNING PFX
663 "Only %d pstates usable (use ACPI driver for full "
664 "range\n", data->batps);
665 data->numps = data->batps;
668 for (j = 1; j < data->numps; j++) {
669 if (pst[j-1].fid >= pst[j].fid) {
670 printk(KERN_ERR PFX "PST out of sequence\n");
671 return -EINVAL;
675 if (data->numps < 2) {
676 printk(KERN_ERR PFX "no p states to transition\n");
677 return -ENODEV;
680 if (check_pst_table(data, pst, maxvid))
681 return -EINVAL;
683 powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table)
684 * (data->numps + 1)), GFP_KERNEL);
685 if (!powernow_table) {
686 printk(KERN_ERR PFX "powernow_table memory alloc failure\n");
687 return -ENOMEM;
690 for (j = 0; j < data->numps; j++) {
691 int freq;
692 powernow_table[j].index = pst[j].fid; /* lower 8 bits */
693 powernow_table[j].index |= (pst[j].vid << 8); /* upper 8 bits */
694 freq = find_khz_freq_from_fid(pst[j].fid);
695 powernow_table[j].frequency = freq;
697 powernow_table[data->numps].frequency = CPUFREQ_TABLE_END;
698 powernow_table[data->numps].index = 0;
700 if (query_current_values_with_pending_wait(data)) {
701 kfree(powernow_table);
702 return -EIO;
705 dprintk("cfid 0x%x, cvid 0x%x\n", data->currfid, data->currvid);
706 data->powernow_table = powernow_table;
707 if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
708 print_basics(data);
710 for (j = 0; j < data->numps; j++)
711 if ((pst[j].fid == data->currfid) &&
712 (pst[j].vid == data->currvid))
713 return 0;
715 dprintk("currfid/vid do not match PST, ignoring\n");
716 return 0;
719 /* Find and validate the PSB/PST table in BIOS. */
720 static int find_psb_table(struct powernow_k8_data *data)
722 struct psb_s *psb;
723 unsigned int i;
724 u32 mvs;
725 u8 maxvid;
726 u32 cpst = 0;
727 u32 thiscpuid;
729 for (i = 0xc0000; i < 0xffff0; i += 0x10) {
730 /* Scan BIOS looking for the signature. */
731 /* It can not be at ffff0 - it is too big. */
733 psb = phys_to_virt(i);
734 if (memcmp(psb, PSB_ID_STRING, PSB_ID_STRING_LEN) != 0)
735 continue;
737 dprintk("found PSB header at 0x%p\n", psb);
739 dprintk("table vers: 0x%x\n", psb->tableversion);
740 if (psb->tableversion != PSB_VERSION_1_4) {
741 printk(KERN_ERR FW_BUG PFX "PSB table is not v1.4\n");
742 return -ENODEV;
745 dprintk("flags: 0x%x\n", psb->flags1);
746 if (psb->flags1) {
747 printk(KERN_ERR FW_BUG PFX "unknown flags\n");
748 return -ENODEV;
751 data->vstable = psb->vstable;
752 dprintk("voltage stabilization time: %d(*20us)\n",
753 data->vstable);
755 dprintk("flags2: 0x%x\n", psb->flags2);
756 data->rvo = psb->flags2 & 3;
757 data->irt = ((psb->flags2) >> 2) & 3;
758 mvs = ((psb->flags2) >> 4) & 3;
759 data->vidmvs = 1 << mvs;
760 data->batps = ((psb->flags2) >> 6) & 3;
762 dprintk("ramp voltage offset: %d\n", data->rvo);
763 dprintk("isochronous relief time: %d\n", data->irt);
764 dprintk("maximum voltage step: %d - 0x%x\n", mvs, data->vidmvs);
766 dprintk("numpst: 0x%x\n", psb->num_tables);
767 cpst = psb->num_tables;
768 if ((psb->cpuid == 0x00000fc0) ||
769 (psb->cpuid == 0x00000fe0)) {
770 thiscpuid = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
771 if ((thiscpuid == 0x00000fc0) ||
772 (thiscpuid == 0x00000fe0))
773 cpst = 1;
775 if (cpst != 1) {
776 printk(KERN_ERR FW_BUG PFX "numpst must be 1\n");
777 return -ENODEV;
780 data->plllock = psb->plllocktime;
781 dprintk("plllocktime: 0x%x (units 1us)\n", psb->plllocktime);
782 dprintk("maxfid: 0x%x\n", psb->maxfid);
783 dprintk("maxvid: 0x%x\n", psb->maxvid);
784 maxvid = psb->maxvid;
786 data->numps = psb->numps;
787 dprintk("numpstates: 0x%x\n", data->numps);
788 return fill_powernow_table(data,
789 (struct pst_s *)(psb+1), maxvid);
792 * If you see this message, complain to BIOS manufacturer. If
793 * he tells you "we do not support Linux" or some similar
794 * nonsense, remember that Windows 2000 uses the same legacy
795 * mechanism that the old Linux PSB driver uses. Tell them it
796 * is broken with Windows 2000.
798 * The reference to the AMD documentation is chapter 9 in the
799 * BIOS and Kernel Developer's Guide, which is available on
800 * www.amd.com
802 printk(KERN_ERR FW_BUG PFX "No PSB or ACPI _PSS objects\n");
803 return -ENODEV;
806 static void powernow_k8_acpi_pst_values(struct powernow_k8_data *data,
807 unsigned int index)
809 acpi_integer control;
811 if (!data->acpi_data.state_count || (cpu_family == CPU_HW_PSTATE))
812 return;
814 control = data->acpi_data.states[index].control;
815 data->irt = (control >> IRT_SHIFT) & IRT_MASK;
816 data->rvo = (control >> RVO_SHIFT) & RVO_MASK;
817 data->exttype = (control >> EXT_TYPE_SHIFT) & EXT_TYPE_MASK;
818 data->plllock = (control >> PLL_L_SHIFT) & PLL_L_MASK;
819 data->vidmvs = 1 << ((control >> MVS_SHIFT) & MVS_MASK);
820 data->vstable = (control >> VST_SHIFT) & VST_MASK;
823 static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
825 struct cpufreq_frequency_table *powernow_table;
826 int ret_val = -ENODEV;
827 acpi_integer control, status;
829 if (acpi_processor_register_performance(&data->acpi_data, data->cpu)) {
830 dprintk("register performance failed: bad ACPI data\n");
831 return -EIO;
834 /* verify the data contained in the ACPI structures */
835 if (data->acpi_data.state_count <= 1) {
836 dprintk("No ACPI P-States\n");
837 goto err_out;
840 control = data->acpi_data.control_register.space_id;
841 status = data->acpi_data.status_register.space_id;
843 if ((control != ACPI_ADR_SPACE_FIXED_HARDWARE) ||
844 (status != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
845 dprintk("Invalid control/status registers (%x - %x)\n",
846 control, status);
847 goto err_out;
850 /* fill in data->powernow_table */
851 powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table)
852 * (data->acpi_data.state_count + 1)), GFP_KERNEL);
853 if (!powernow_table) {
854 dprintk("powernow_table memory alloc failure\n");
855 goto err_out;
858 /* fill in data */
859 data->numps = data->acpi_data.state_count;
860 powernow_k8_acpi_pst_values(data, 0);
862 if (cpu_family == CPU_HW_PSTATE)
863 ret_val = fill_powernow_table_pstate(data, powernow_table);
864 else
865 ret_val = fill_powernow_table_fidvid(data, powernow_table);
866 if (ret_val)
867 goto err_out_mem;
869 powernow_table[data->acpi_data.state_count].frequency =
870 CPUFREQ_TABLE_END;
871 powernow_table[data->acpi_data.state_count].index = 0;
872 data->powernow_table = powernow_table;
874 if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
875 print_basics(data);
877 /* notify BIOS that we exist */
878 acpi_processor_notify_smm(THIS_MODULE);
880 if (!zalloc_cpumask_var(&data->acpi_data.shared_cpu_map, GFP_KERNEL)) {
881 printk(KERN_ERR PFX
882 "unable to alloc powernow_k8_data cpumask\n");
883 ret_val = -ENOMEM;
884 goto err_out_mem;
887 return 0;
889 err_out_mem:
890 kfree(powernow_table);
892 err_out:
893 acpi_processor_unregister_performance(&data->acpi_data, data->cpu);
895 /* data->acpi_data.state_count informs us at ->exit()
896 * whether ACPI was used */
897 data->acpi_data.state_count = 0;
899 return ret_val;
902 static int fill_powernow_table_pstate(struct powernow_k8_data *data,
903 struct cpufreq_frequency_table *powernow_table)
905 int i;
906 u32 hi = 0, lo = 0;
907 rdmsr(MSR_PSTATE_CUR_LIMIT, hi, lo);
908 data->max_hw_pstate = (hi & HW_PSTATE_MAX_MASK) >> HW_PSTATE_MAX_SHIFT;
910 for (i = 0; i < data->acpi_data.state_count; i++) {
911 u32 index;
913 index = data->acpi_data.states[i].control & HW_PSTATE_MASK;
914 if (index > data->max_hw_pstate) {
915 printk(KERN_ERR PFX "invalid pstate %d - "
916 "bad value %d.\n", i, index);
917 printk(KERN_ERR PFX "Please report to BIOS "
918 "manufacturer\n");
919 invalidate_entry(powernow_table, i);
920 continue;
922 rdmsr(MSR_PSTATE_DEF_BASE + index, lo, hi);
923 if (!(hi & HW_PSTATE_VALID_MASK)) {
924 dprintk("invalid pstate %d, ignoring\n", index);
925 invalidate_entry(powernow_table, i);
926 continue;
929 powernow_table[i].index = index;
931 /* Frequency may be rounded for these */
932 if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
933 || boot_cpu_data.x86 == 0x11) {
934 powernow_table[i].frequency =
935 freq_from_fid_did(lo & 0x3f, (lo >> 6) & 7);
936 } else
937 powernow_table[i].frequency =
938 data->acpi_data.states[i].core_frequency * 1000;
940 return 0;
943 static int fill_powernow_table_fidvid(struct powernow_k8_data *data,
944 struct cpufreq_frequency_table *powernow_table)
946 int i;
948 for (i = 0; i < data->acpi_data.state_count; i++) {
949 u32 fid;
950 u32 vid;
951 u32 freq, index;
952 acpi_integer status, control;
954 if (data->exttype) {
955 status = data->acpi_data.states[i].status;
956 fid = status & EXT_FID_MASK;
957 vid = (status >> VID_SHIFT) & EXT_VID_MASK;
958 } else {
959 control = data->acpi_data.states[i].control;
960 fid = control & FID_MASK;
961 vid = (control >> VID_SHIFT) & VID_MASK;
964 dprintk(" %d : fid 0x%x, vid 0x%x\n", i, fid, vid);
966 index = fid | (vid<<8);
967 powernow_table[i].index = index;
969 freq = find_khz_freq_from_fid(fid);
970 powernow_table[i].frequency = freq;
972 /* verify frequency is OK */
973 if ((freq > (MAX_FREQ * 1000)) || (freq < (MIN_FREQ * 1000))) {
974 dprintk("invalid freq %u kHz, ignoring\n", freq);
975 invalidate_entry(powernow_table, i);
976 continue;
979 /* verify voltage is OK -
980 * BIOSs are using "off" to indicate invalid */
981 if (vid == VID_OFF) {
982 dprintk("invalid vid %u, ignoring\n", vid);
983 invalidate_entry(powernow_table, i);
984 continue;
987 if (freq != (data->acpi_data.states[i].core_frequency * 1000)) {
988 printk(KERN_INFO PFX "invalid freq entries "
989 "%u kHz vs. %u kHz\n", freq,
990 (unsigned int)
991 (data->acpi_data.states[i].core_frequency
992 * 1000));
993 invalidate_entry(powernow_table, i);
994 continue;
997 return 0;
1000 static void powernow_k8_cpu_exit_acpi(struct powernow_k8_data *data)
1002 if (data->acpi_data.state_count)
1003 acpi_processor_unregister_performance(&data->acpi_data,
1004 data->cpu);
1005 free_cpumask_var(data->acpi_data.shared_cpu_map);
1008 static int get_transition_latency(struct powernow_k8_data *data)
1010 int max_latency = 0;
1011 int i;
1012 for (i = 0; i < data->acpi_data.state_count; i++) {
1013 int cur_latency = data->acpi_data.states[i].transition_latency
1014 + data->acpi_data.states[i].bus_master_latency;
1015 if (cur_latency > max_latency)
1016 max_latency = cur_latency;
1018 if (max_latency == 0) {
1020 * Fam 11h always returns 0 as transition latency.
1021 * This is intended and means "very fast". While cpufreq core
1022 * and governors currently can handle that gracefully, better
1023 * set it to 1 to avoid problems in the future.
1024 * For all others it's a BIOS bug.
1026 if (boot_cpu_data.x86 != 0x11)
1027 printk(KERN_ERR FW_WARN PFX "Invalid zero transition "
1028 "latency\n");
1029 max_latency = 1;
1031 /* value in usecs, needs to be in nanoseconds */
1032 return 1000 * max_latency;
1035 /* Take a frequency, and issue the fid/vid transition command */
1036 static int transition_frequency_fidvid(struct powernow_k8_data *data,
1037 unsigned int index)
1039 u32 fid = 0;
1040 u32 vid = 0;
1041 int res, i;
1042 struct cpufreq_freqs freqs;
1044 dprintk("cpu %d transition to index %u\n", smp_processor_id(), index);
1046 /* fid/vid correctness check for k8 */
1047 /* fid are the lower 8 bits of the index we stored into
1048 * the cpufreq frequency table in find_psb_table, vid
1049 * are the upper 8 bits.
1051 fid = data->powernow_table[index].index & 0xFF;
1052 vid = (data->powernow_table[index].index & 0xFF00) >> 8;
1054 dprintk("table matched fid 0x%x, giving vid 0x%x\n", fid, vid);
1056 if (query_current_values_with_pending_wait(data))
1057 return 1;
1059 if ((data->currvid == vid) && (data->currfid == fid)) {
1060 dprintk("target matches current values (fid 0x%x, vid 0x%x)\n",
1061 fid, vid);
1062 return 0;
1065 dprintk("cpu %d, changing to fid 0x%x, vid 0x%x\n",
1066 smp_processor_id(), fid, vid);
1067 freqs.old = find_khz_freq_from_fid(data->currfid);
1068 freqs.new = find_khz_freq_from_fid(fid);
1070 for_each_cpu(i, data->available_cores) {
1071 freqs.cpu = i;
1072 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
1075 res = transition_fid_vid(data, fid, vid);
1076 freqs.new = find_khz_freq_from_fid(data->currfid);
1078 for_each_cpu(i, data->available_cores) {
1079 freqs.cpu = i;
1080 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
1082 return res;
1085 /* Take a frequency, and issue the hardware pstate transition command */
1086 static int transition_frequency_pstate(struct powernow_k8_data *data,
1087 unsigned int index)
1089 u32 pstate = 0;
1090 int res, i;
1091 struct cpufreq_freqs freqs;
1093 dprintk("cpu %d transition to index %u\n", smp_processor_id(), index);
1095 /* get MSR index for hardware pstate transition */
1096 pstate = index & HW_PSTATE_MASK;
1097 if (pstate > data->max_hw_pstate)
1098 return 0;
1099 freqs.old = find_khz_freq_from_pstate(data->powernow_table,
1100 data->currpstate);
1101 freqs.new = find_khz_freq_from_pstate(data->powernow_table, pstate);
1103 for_each_cpu(i, data->available_cores) {
1104 freqs.cpu = i;
1105 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
1108 res = transition_pstate(data, pstate);
1109 freqs.new = find_khz_freq_from_pstate(data->powernow_table, pstate);
1111 for_each_cpu(i, data->available_cores) {
1112 freqs.cpu = i;
1113 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
1115 return res;
1118 /* Driver entry point to switch to the target frequency */
1119 static int powernowk8_target(struct cpufreq_policy *pol,
1120 unsigned targfreq, unsigned relation)
1122 cpumask_t oldmask;
1123 struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1124 u32 checkfid;
1125 u32 checkvid;
1126 unsigned int newstate;
1127 int ret = -EIO;
1129 if (!data)
1130 return -EINVAL;
1132 checkfid = data->currfid;
1133 checkvid = data->currvid;
1135 /* only run on specific CPU from here on */
1136 oldmask = current->cpus_allowed;
1137 set_cpus_allowed_ptr(current, &cpumask_of_cpu(pol->cpu));
1139 if (smp_processor_id() != pol->cpu) {
1140 printk(KERN_ERR PFX "limiting to cpu %u failed\n", pol->cpu);
1141 goto err_out;
1144 if (pending_bit_stuck()) {
1145 printk(KERN_ERR PFX "failing targ, change pending bit set\n");
1146 goto err_out;
1149 dprintk("targ: cpu %d, %d kHz, min %d, max %d, relation %d\n",
1150 pol->cpu, targfreq, pol->min, pol->max, relation);
1152 if (query_current_values_with_pending_wait(data))
1153 goto err_out;
1155 if (cpu_family != CPU_HW_PSTATE) {
1156 dprintk("targ: curr fid 0x%x, vid 0x%x\n",
1157 data->currfid, data->currvid);
1159 if ((checkvid != data->currvid) ||
1160 (checkfid != data->currfid)) {
1161 printk(KERN_INFO PFX
1162 "error - out of sync, fix 0x%x 0x%x, "
1163 "vid 0x%x 0x%x\n",
1164 checkfid, data->currfid,
1165 checkvid, data->currvid);
1169 if (cpufreq_frequency_table_target(pol, data->powernow_table,
1170 targfreq, relation, &newstate))
1171 goto err_out;
1173 mutex_lock(&fidvid_mutex);
1175 powernow_k8_acpi_pst_values(data, newstate);
1177 if (cpu_family == CPU_HW_PSTATE)
1178 ret = transition_frequency_pstate(data, newstate);
1179 else
1180 ret = transition_frequency_fidvid(data, newstate);
1181 if (ret) {
1182 printk(KERN_ERR PFX "transition frequency failed\n");
1183 ret = 1;
1184 mutex_unlock(&fidvid_mutex);
1185 goto err_out;
1187 mutex_unlock(&fidvid_mutex);
1189 if (cpu_family == CPU_HW_PSTATE)
1190 pol->cur = find_khz_freq_from_pstate(data->powernow_table,
1191 newstate);
1192 else
1193 pol->cur = find_khz_freq_from_fid(data->currfid);
1194 ret = 0;
1196 err_out:
1197 set_cpus_allowed_ptr(current, &oldmask);
1198 return ret;
1201 /* Driver entry point to verify the policy and range of frequencies */
1202 static int powernowk8_verify(struct cpufreq_policy *pol)
1204 struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1206 if (!data)
1207 return -EINVAL;
1209 return cpufreq_frequency_table_verify(pol, data->powernow_table);
1212 struct init_on_cpu {
1213 struct powernow_k8_data *data;
1214 int rc;
1217 static void __cpuinit powernowk8_cpu_init_on_cpu(void *_init_on_cpu)
1219 struct init_on_cpu *init_on_cpu = _init_on_cpu;
1221 if (pending_bit_stuck()) {
1222 printk(KERN_ERR PFX "failing init, change pending bit set\n");
1223 init_on_cpu->rc = -ENODEV;
1224 return;
1227 if (query_current_values_with_pending_wait(init_on_cpu->data)) {
1228 init_on_cpu->rc = -ENODEV;
1229 return;
1232 if (cpu_family == CPU_OPTERON)
1233 fidvid_msr_init();
1235 init_on_cpu->rc = 0;
1238 /* per CPU init entry point to the driver */
1239 static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
1241 static const char ACPI_PSS_BIOS_BUG_MSG[] =
1242 KERN_ERR FW_BUG PFX "No compatible ACPI _PSS objects found.\n"
1243 FW_BUG PFX "Try again with latest BIOS.\n";
1244 struct powernow_k8_data *data;
1245 struct init_on_cpu init_on_cpu;
1246 int rc;
1248 if (!cpu_online(pol->cpu))
1249 return -ENODEV;
1251 smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1);
1252 if (rc)
1253 return -ENODEV;
1255 data = kzalloc(sizeof(struct powernow_k8_data), GFP_KERNEL);
1256 if (!data) {
1257 printk(KERN_ERR PFX "unable to alloc powernow_k8_data");
1258 return -ENOMEM;
1261 data->cpu = pol->cpu;
1262 data->currpstate = HW_PSTATE_INVALID;
1264 if (powernow_k8_cpu_init_acpi(data)) {
1266 * Use the PSB BIOS structure. This is only availabe on
1267 * an UP version, and is deprecated by AMD.
1269 if (num_online_cpus() != 1) {
1270 printk_once(ACPI_PSS_BIOS_BUG_MSG);
1271 goto err_out;
1273 if (pol->cpu != 0) {
1274 printk(KERN_ERR FW_BUG PFX "No ACPI _PSS objects for "
1275 "CPU other than CPU0. Complain to your BIOS "
1276 "vendor.\n");
1277 goto err_out;
1279 rc = find_psb_table(data);
1280 if (rc)
1281 goto err_out;
1283 /* Take a crude guess here.
1284 * That guess was in microseconds, so multiply with 1000 */
1285 pol->cpuinfo.transition_latency = (
1286 ((data->rvo + 8) * data->vstable * VST_UNITS_20US) +
1287 ((1 << data->irt) * 30)) * 1000;
1288 } else /* ACPI _PSS objects available */
1289 pol->cpuinfo.transition_latency = get_transition_latency(data);
1291 /* only run on specific CPU from here on */
1292 init_on_cpu.data = data;
1293 smp_call_function_single(data->cpu, powernowk8_cpu_init_on_cpu,
1294 &init_on_cpu, 1);
1295 rc = init_on_cpu.rc;
1296 if (rc != 0)
1297 goto err_out_exit_acpi;
1299 if (cpu_family == CPU_HW_PSTATE)
1300 cpumask_copy(pol->cpus, cpumask_of(pol->cpu));
1301 else
1302 cpumask_copy(pol->cpus, cpu_core_mask(pol->cpu));
1303 data->available_cores = pol->cpus;
1305 if (cpu_family == CPU_HW_PSTATE)
1306 pol->cur = find_khz_freq_from_pstate(data->powernow_table,
1307 data->currpstate);
1308 else
1309 pol->cur = find_khz_freq_from_fid(data->currfid);
1310 dprintk("policy current frequency %d kHz\n", pol->cur);
1312 /* min/max the cpu is capable of */
1313 if (cpufreq_frequency_table_cpuinfo(pol, data->powernow_table)) {
1314 printk(KERN_ERR FW_BUG PFX "invalid powernow_table\n");
1315 powernow_k8_cpu_exit_acpi(data);
1316 kfree(data->powernow_table);
1317 kfree(data);
1318 return -EINVAL;
1321 cpufreq_frequency_table_get_attr(data->powernow_table, pol->cpu);
1323 if (cpu_family == CPU_HW_PSTATE)
1324 dprintk("cpu_init done, current pstate 0x%x\n",
1325 data->currpstate);
1326 else
1327 dprintk("cpu_init done, current fid 0x%x, vid 0x%x\n",
1328 data->currfid, data->currvid);
1330 per_cpu(powernow_data, pol->cpu) = data;
1332 return 0;
1334 err_out_exit_acpi:
1335 powernow_k8_cpu_exit_acpi(data);
1337 err_out:
1338 kfree(data);
1339 return -ENODEV;
1342 static int __devexit powernowk8_cpu_exit(struct cpufreq_policy *pol)
1344 struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1346 if (!data)
1347 return -EINVAL;
1349 powernow_k8_cpu_exit_acpi(data);
1351 cpufreq_frequency_table_put_attr(pol->cpu);
1353 kfree(data->powernow_table);
1354 kfree(data);
1355 per_cpu(powernow_data, pol->cpu) = NULL;
1357 return 0;
1360 static void query_values_on_cpu(void *_err)
1362 int *err = _err;
1363 struct powernow_k8_data *data = __get_cpu_var(powernow_data);
1365 *err = query_current_values_with_pending_wait(data);
1368 static unsigned int powernowk8_get(unsigned int cpu)
1370 struct powernow_k8_data *data = per_cpu(powernow_data, cpu);
1371 unsigned int khz = 0;
1372 int err;
1374 if (!data)
1375 return 0;
1377 smp_call_function_single(cpu, query_values_on_cpu, &err, true);
1378 if (err)
1379 goto out;
1381 if (cpu_family == CPU_HW_PSTATE)
1382 khz = find_khz_freq_from_pstate(data->powernow_table,
1383 data->currpstate);
1384 else
1385 khz = find_khz_freq_from_fid(data->currfid);
1388 out:
1389 return khz;
1392 static struct freq_attr *powernow_k8_attr[] = {
1393 &cpufreq_freq_attr_scaling_available_freqs,
1394 NULL,
1397 static struct cpufreq_driver cpufreq_amd64_driver = {
1398 .verify = powernowk8_verify,
1399 .target = powernowk8_target,
1400 .init = powernowk8_cpu_init,
1401 .exit = __devexit_p(powernowk8_cpu_exit),
1402 .get = powernowk8_get,
1403 .name = "powernow-k8",
1404 .owner = THIS_MODULE,
1405 .attr = powernow_k8_attr,
1408 /* driver entry point for init */
1409 static int __cpuinit powernowk8_init(void)
1411 unsigned int i, supported_cpus = 0;
1413 for_each_online_cpu(i) {
1414 int rc;
1415 smp_call_function_single(i, check_supported_cpu, &rc, 1);
1416 if (rc == 0)
1417 supported_cpus++;
1420 if (supported_cpus == num_online_cpus()) {
1421 printk(KERN_INFO PFX "Found %d %s "
1422 "processors (%d cpu cores) (" VERSION ")\n",
1423 num_online_nodes(),
1424 boot_cpu_data.x86_model_id, supported_cpus);
1425 return cpufreq_register_driver(&cpufreq_amd64_driver);
1428 return -ENODEV;
1431 /* driver entry point for term */
1432 static void __exit powernowk8_exit(void)
1434 dprintk("exit\n");
1436 cpufreq_unregister_driver(&cpufreq_amd64_driver);
1439 MODULE_AUTHOR("Paul Devriendt <paul.devriendt@amd.com> and "
1440 "Mark Langsdorf <mark.langsdorf@amd.com>");
1441 MODULE_DESCRIPTION("AMD Athlon 64 and Opteron processor frequency driver.");
1442 MODULE_LICENSE("GPL");
1444 late_initcall(powernowk8_init);
1445 module_exit(powernowk8_exit);