Merge remote-tracking branch 'slab/for-next'
[linux-2.6/next.git] / drivers / cpufreq / powernow-k8.c
blobbce576d7478ed41f9b69ac727cc5d143d850bb83
1 /*
2 * (c) 2003-2010 Advanced Micro Devices, Inc.
3 * Your use of this code is subject to the terms and conditions of the
4 * GNU general public license version 2. See "COPYING" or
5 * http://www.gnu.org/licenses/gpl.html
7 * Support : mark.langsdorf@amd.com
9 * Based on the powernow-k7.c module written by Dave Jones.
10 * (C) 2003 Dave Jones on behalf of SuSE Labs
11 * (C) 2004 Dominik Brodowski <linux@brodo.de>
12 * (C) 2004 Pavel Machek <pavel@ucw.cz>
13 * Licensed under the terms of the GNU GPL License version 2.
14 * Based upon datasheets & sample CPUs kindly provided by AMD.
16 * Valuable input gratefully received from Dave Jones, Pavel Machek,
17 * Dominik Brodowski, Jacob Shin, and others.
18 * Originally developed by Paul Devriendt.
19 * Processor information obtained from Chapter 9 (Power and Thermal Management)
20 * of the "BIOS and Kernel Developer's Guide for the AMD Athlon 64 and AMD
21 * Opteron Processors" available for download from www.amd.com
23 * Tables for specific CPUs can be inferred from
24 * http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/30430.pdf
27 #include <linux/kernel.h>
28 #include <linux/smp.h>
29 #include <linux/module.h>
30 #include <linux/init.h>
31 #include <linux/cpufreq.h>
32 #include <linux/slab.h>
33 #include <linux/string.h>
34 #include <linux/cpumask.h>
35 #include <linux/sched.h> /* for current / set_cpus_allowed() */
36 #include <linux/io.h>
37 #include <linux/delay.h>
39 #include <asm/msr.h>
41 #include <linux/acpi.h>
42 #include <linux/mutex.h>
43 #include <acpi/processor.h>
45 #define PFX "powernow-k8: "
46 #define VERSION "version 2.20.00"
47 #include "powernow-k8.h"
48 #include "mperf.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 /* core performance boost */
58 static bool cpb_capable, cpb_enabled;
59 static struct msr __percpu *msrs;
61 static struct cpufreq_driver cpufreq_amd64_driver;
63 #ifndef CONFIG_SMP
64 static inline const struct cpumask *cpu_core_mask(int cpu)
66 return cpumask_of(0);
68 #endif
70 /* Return a frequency in MHz, given an input fid */
71 static u32 find_freq_from_fid(u32 fid)
73 return 800 + (fid * 100);
76 /* Return a frequency in KHz, given an input fid */
77 static u32 find_khz_freq_from_fid(u32 fid)
79 return 1000 * find_freq_from_fid(fid);
82 static u32 find_khz_freq_from_pstate(struct cpufreq_frequency_table *data,
83 u32 pstate)
85 return data[pstate].frequency;
88 /* Return the vco fid for an input fid
90 * Each "low" fid has corresponding "high" fid, and you can get to "low" fids
91 * only from corresponding high fids. This returns "high" fid corresponding to
92 * "low" one.
94 static u32 convert_fid_to_vco_fid(u32 fid)
96 if (fid < HI_FID_TABLE_BOTTOM)
97 return 8 + (2 * fid);
98 else
99 return fid;
103 * Return 1 if the pending bit is set. Unless we just instructed the processor
104 * to transition to a new state, seeing this bit set is really bad news.
106 static int pending_bit_stuck(void)
108 u32 lo, hi;
110 if (cpu_family == CPU_HW_PSTATE)
111 return 0;
113 rdmsr(MSR_FIDVID_STATUS, lo, hi);
114 return lo & MSR_S_LO_CHANGE_PENDING ? 1 : 0;
118 * Update the global current fid / vid values from the status msr.
119 * Returns 1 on error.
121 static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
123 u32 lo, hi;
124 u32 i = 0;
126 if (cpu_family == CPU_HW_PSTATE) {
127 rdmsr(MSR_PSTATE_STATUS, lo, hi);
128 i = lo & HW_PSTATE_MASK;
129 data->currpstate = i;
132 * a workaround for family 11h erratum 311 might cause
133 * an "out-of-range Pstate if the core is in Pstate-0
135 if ((boot_cpu_data.x86 == 0x11) && (i >= data->numps))
136 data->currpstate = HW_PSTATE_0;
138 return 0;
140 do {
141 if (i++ > 10000) {
142 pr_debug("detected change pending stuck\n");
143 return 1;
145 rdmsr(MSR_FIDVID_STATUS, lo, hi);
146 } while (lo & MSR_S_LO_CHANGE_PENDING);
148 data->currvid = hi & MSR_S_HI_CURRENT_VID;
149 data->currfid = lo & MSR_S_LO_CURRENT_FID;
151 return 0;
154 /* the isochronous relief time */
155 static void count_off_irt(struct powernow_k8_data *data)
157 udelay((1 << data->irt) * 10);
158 return;
161 /* the voltage stabilization time */
162 static void count_off_vst(struct powernow_k8_data *data)
164 udelay(data->vstable * VST_UNITS_20US);
165 return;
168 /* need to init the control msr to a safe value (for each cpu) */
169 static void fidvid_msr_init(void)
171 u32 lo, hi;
172 u8 fid, vid;
174 rdmsr(MSR_FIDVID_STATUS, lo, hi);
175 vid = hi & MSR_S_HI_CURRENT_VID;
176 fid = lo & MSR_S_LO_CURRENT_FID;
177 lo = fid | (vid << MSR_C_LO_VID_SHIFT);
178 hi = MSR_C_HI_STP_GNT_BENIGN;
179 pr_debug("cpu%d, init lo 0x%x, hi 0x%x\n", smp_processor_id(), lo, hi);
180 wrmsr(MSR_FIDVID_CTL, lo, hi);
183 /* write the new fid value along with the other control fields to the msr */
184 static int write_new_fid(struct powernow_k8_data *data, u32 fid)
186 u32 lo;
187 u32 savevid = data->currvid;
188 u32 i = 0;
190 if ((fid & INVALID_FID_MASK) || (data->currvid & INVALID_VID_MASK)) {
191 printk(KERN_ERR PFX "internal error - overflow on fid write\n");
192 return 1;
195 lo = fid;
196 lo |= (data->currvid << MSR_C_LO_VID_SHIFT);
197 lo |= MSR_C_LO_INIT_FID_VID;
199 pr_debug("writing fid 0x%x, lo 0x%x, hi 0x%x\n",
200 fid, lo, data->plllock * PLL_LOCK_CONVERSION);
202 do {
203 wrmsr(MSR_FIDVID_CTL, lo, data->plllock * PLL_LOCK_CONVERSION);
204 if (i++ > 100) {
205 printk(KERN_ERR PFX
206 "Hardware error - pending bit very stuck - "
207 "no further pstate changes possible\n");
208 return 1;
210 } while (query_current_values_with_pending_wait(data));
212 count_off_irt(data);
214 if (savevid != data->currvid) {
215 printk(KERN_ERR PFX
216 "vid change on fid trans, old 0x%x, new 0x%x\n",
217 savevid, data->currvid);
218 return 1;
221 if (fid != data->currfid) {
222 printk(KERN_ERR PFX
223 "fid trans failed, fid 0x%x, curr 0x%x\n", fid,
224 data->currfid);
225 return 1;
228 return 0;
231 /* Write a new vid to the hardware */
232 static int write_new_vid(struct powernow_k8_data *data, u32 vid)
234 u32 lo;
235 u32 savefid = data->currfid;
236 int i = 0;
238 if ((data->currfid & INVALID_FID_MASK) || (vid & INVALID_VID_MASK)) {
239 printk(KERN_ERR PFX "internal error - overflow on vid write\n");
240 return 1;
243 lo = data->currfid;
244 lo |= (vid << MSR_C_LO_VID_SHIFT);
245 lo |= MSR_C_LO_INIT_FID_VID;
247 pr_debug("writing vid 0x%x, lo 0x%x, hi 0x%x\n",
248 vid, lo, STOP_GRANT_5NS);
250 do {
251 wrmsr(MSR_FIDVID_CTL, lo, STOP_GRANT_5NS);
252 if (i++ > 100) {
253 printk(KERN_ERR PFX "internal error - pending bit "
254 "very stuck - no further pstate "
255 "changes possible\n");
256 return 1;
258 } while (query_current_values_with_pending_wait(data));
260 if (savefid != data->currfid) {
261 printk(KERN_ERR PFX "fid changed on vid trans, old "
262 "0x%x new 0x%x\n",
263 savefid, data->currfid);
264 return 1;
267 if (vid != data->currvid) {
268 printk(KERN_ERR PFX "vid trans failed, vid 0x%x, "
269 "curr 0x%x\n",
270 vid, data->currvid);
271 return 1;
274 return 0;
278 * Reduce the vid by the max of step or reqvid.
279 * Decreasing vid codes represent increasing voltages:
280 * vid of 0 is 1.550V, vid of 0x1e is 0.800V, vid of VID_OFF is off.
282 static int decrease_vid_code_by_step(struct powernow_k8_data *data,
283 u32 reqvid, u32 step)
285 if ((data->currvid - reqvid) > step)
286 reqvid = data->currvid - step;
288 if (write_new_vid(data, reqvid))
289 return 1;
291 count_off_vst(data);
293 return 0;
296 /* Change hardware pstate by single MSR write */
297 static int transition_pstate(struct powernow_k8_data *data, u32 pstate)
299 wrmsr(MSR_PSTATE_CTRL, pstate, 0);
300 data->currpstate = pstate;
301 return 0;
304 /* Change Opteron/Athlon64 fid and vid, by the 3 phases. */
305 static int transition_fid_vid(struct powernow_k8_data *data,
306 u32 reqfid, u32 reqvid)
308 if (core_voltage_pre_transition(data, reqvid, reqfid))
309 return 1;
311 if (core_frequency_transition(data, reqfid))
312 return 1;
314 if (core_voltage_post_transition(data, reqvid))
315 return 1;
317 if (query_current_values_with_pending_wait(data))
318 return 1;
320 if ((reqfid != data->currfid) || (reqvid != data->currvid)) {
321 printk(KERN_ERR PFX "failed (cpu%d): req 0x%x 0x%x, "
322 "curr 0x%x 0x%x\n",
323 smp_processor_id(),
324 reqfid, reqvid, data->currfid, data->currvid);
325 return 1;
328 pr_debug("transitioned (cpu%d): new fid 0x%x, vid 0x%x\n",
329 smp_processor_id(), data->currfid, data->currvid);
331 return 0;
334 /* Phase 1 - core voltage transition ... setup voltage */
335 static int core_voltage_pre_transition(struct powernow_k8_data *data,
336 u32 reqvid, u32 reqfid)
338 u32 rvosteps = data->rvo;
339 u32 savefid = data->currfid;
340 u32 maxvid, lo, rvomult = 1;
342 pr_debug("ph1 (cpu%d): start, currfid 0x%x, currvid 0x%x, "
343 "reqvid 0x%x, rvo 0x%x\n",
344 smp_processor_id(),
345 data->currfid, data->currvid, reqvid, data->rvo);
347 if ((savefid < LO_FID_TABLE_TOP) && (reqfid < LO_FID_TABLE_TOP))
348 rvomult = 2;
349 rvosteps *= rvomult;
350 rdmsr(MSR_FIDVID_STATUS, lo, maxvid);
351 maxvid = 0x1f & (maxvid >> 16);
352 pr_debug("ph1 maxvid=0x%x\n", maxvid);
353 if (reqvid < maxvid) /* lower numbers are higher voltages */
354 reqvid = maxvid;
356 while (data->currvid > reqvid) {
357 pr_debug("ph1: curr 0x%x, req vid 0x%x\n",
358 data->currvid, reqvid);
359 if (decrease_vid_code_by_step(data, reqvid, data->vidmvs))
360 return 1;
363 while ((rvosteps > 0) &&
364 ((rvomult * data->rvo + data->currvid) > reqvid)) {
365 if (data->currvid == maxvid) {
366 rvosteps = 0;
367 } else {
368 pr_debug("ph1: changing vid for rvo, req 0x%x\n",
369 data->currvid - 1);
370 if (decrease_vid_code_by_step(data, data->currvid-1, 1))
371 return 1;
372 rvosteps--;
376 if (query_current_values_with_pending_wait(data))
377 return 1;
379 if (savefid != data->currfid) {
380 printk(KERN_ERR PFX "ph1 err, currfid changed 0x%x\n",
381 data->currfid);
382 return 1;
385 pr_debug("ph1 complete, currfid 0x%x, currvid 0x%x\n",
386 data->currfid, data->currvid);
388 return 0;
391 /* Phase 2 - core frequency transition */
392 static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid)
394 u32 vcoreqfid, vcocurrfid, vcofiddiff;
395 u32 fid_interval, savevid = data->currvid;
397 if (data->currfid == reqfid) {
398 printk(KERN_ERR PFX "ph2 null fid transition 0x%x\n",
399 data->currfid);
400 return 0;
403 pr_debug("ph2 (cpu%d): starting, currfid 0x%x, currvid 0x%x, "
404 "reqfid 0x%x\n",
405 smp_processor_id(),
406 data->currfid, data->currvid, reqfid);
408 vcoreqfid = convert_fid_to_vco_fid(reqfid);
409 vcocurrfid = convert_fid_to_vco_fid(data->currfid);
410 vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
411 : vcoreqfid - vcocurrfid;
413 if ((reqfid <= LO_FID_TABLE_TOP) && (data->currfid <= LO_FID_TABLE_TOP))
414 vcofiddiff = 0;
416 while (vcofiddiff > 2) {
417 (data->currfid & 1) ? (fid_interval = 1) : (fid_interval = 2);
419 if (reqfid > data->currfid) {
420 if (data->currfid > LO_FID_TABLE_TOP) {
421 if (write_new_fid(data,
422 data->currfid + fid_interval))
423 return 1;
424 } else {
425 if (write_new_fid
426 (data,
427 2 + convert_fid_to_vco_fid(data->currfid)))
428 return 1;
430 } else {
431 if (write_new_fid(data, data->currfid - fid_interval))
432 return 1;
435 vcocurrfid = convert_fid_to_vco_fid(data->currfid);
436 vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
437 : vcoreqfid - vcocurrfid;
440 if (write_new_fid(data, reqfid))
441 return 1;
443 if (query_current_values_with_pending_wait(data))
444 return 1;
446 if (data->currfid != reqfid) {
447 printk(KERN_ERR PFX
448 "ph2: mismatch, failed fid transition, "
449 "curr 0x%x, req 0x%x\n",
450 data->currfid, reqfid);
451 return 1;
454 if (savevid != data->currvid) {
455 printk(KERN_ERR PFX "ph2: vid changed, save 0x%x, curr 0x%x\n",
456 savevid, data->currvid);
457 return 1;
460 pr_debug("ph2 complete, currfid 0x%x, currvid 0x%x\n",
461 data->currfid, data->currvid);
463 return 0;
466 /* Phase 3 - core voltage transition flow ... jump to the final vid. */
467 static int core_voltage_post_transition(struct powernow_k8_data *data,
468 u32 reqvid)
470 u32 savefid = data->currfid;
471 u32 savereqvid = reqvid;
473 pr_debug("ph3 (cpu%d): starting, currfid 0x%x, currvid 0x%x\n",
474 smp_processor_id(),
475 data->currfid, data->currvid);
477 if (reqvid != data->currvid) {
478 if (write_new_vid(data, reqvid))
479 return 1;
481 if (savefid != data->currfid) {
482 printk(KERN_ERR PFX
483 "ph3: bad fid change, save 0x%x, curr 0x%x\n",
484 savefid, data->currfid);
485 return 1;
488 if (data->currvid != reqvid) {
489 printk(KERN_ERR PFX
490 "ph3: failed vid transition\n, "
491 "req 0x%x, curr 0x%x",
492 reqvid, data->currvid);
493 return 1;
497 if (query_current_values_with_pending_wait(data))
498 return 1;
500 if (savereqvid != data->currvid) {
501 pr_debug("ph3 failed, currvid 0x%x\n", data->currvid);
502 return 1;
505 if (savefid != data->currfid) {
506 pr_debug("ph3 failed, currfid changed 0x%x\n",
507 data->currfid);
508 return 1;
511 pr_debug("ph3 complete, currfid 0x%x, currvid 0x%x\n",
512 data->currfid, data->currvid);
514 return 0;
517 static void check_supported_cpu(void *_rc)
519 u32 eax, ebx, ecx, edx;
520 int *rc = _rc;
522 *rc = -ENODEV;
524 if (__this_cpu_read(cpu_info.x86_vendor) != X86_VENDOR_AMD)
525 return;
527 eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
528 if (((eax & CPUID_XFAM) != CPUID_XFAM_K8) &&
529 ((eax & CPUID_XFAM) < CPUID_XFAM_10H))
530 return;
532 if ((eax & CPUID_XFAM) == CPUID_XFAM_K8) {
533 if (((eax & CPUID_USE_XFAM_XMOD) != CPUID_USE_XFAM_XMOD) ||
534 ((eax & CPUID_XMOD) > CPUID_XMOD_REV_MASK)) {
535 printk(KERN_INFO PFX
536 "Processor cpuid %x not supported\n", eax);
537 return;
540 eax = cpuid_eax(CPUID_GET_MAX_CAPABILITIES);
541 if (eax < CPUID_FREQ_VOLT_CAPABILITIES) {
542 printk(KERN_INFO PFX
543 "No frequency change capabilities detected\n");
544 return;
547 cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
548 if ((edx & P_STATE_TRANSITION_CAPABLE)
549 != P_STATE_TRANSITION_CAPABLE) {
550 printk(KERN_INFO PFX
551 "Power state transitions not supported\n");
552 return;
554 } else { /* must be a HW Pstate capable processor */
555 cpuid(CPUID_FREQ_VOLT_CAPABILITIES, &eax, &ebx, &ecx, &edx);
556 if ((edx & USE_HW_PSTATE) == USE_HW_PSTATE)
557 cpu_family = CPU_HW_PSTATE;
558 else
559 return;
562 *rc = 0;
565 static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst,
566 u8 maxvid)
568 unsigned int j;
569 u8 lastfid = 0xff;
571 for (j = 0; j < data->numps; j++) {
572 if (pst[j].vid > LEAST_VID) {
573 printk(KERN_ERR FW_BUG PFX "vid %d invalid : 0x%x\n",
574 j, pst[j].vid);
575 return -EINVAL;
577 if (pst[j].vid < data->rvo) {
578 /* vid + rvo >= 0 */
579 printk(KERN_ERR FW_BUG PFX "0 vid exceeded with pstate"
580 " %d\n", j);
581 return -ENODEV;
583 if (pst[j].vid < maxvid + data->rvo) {
584 /* vid + rvo >= maxvid */
585 printk(KERN_ERR FW_BUG PFX "maxvid exceeded with pstate"
586 " %d\n", j);
587 return -ENODEV;
589 if (pst[j].fid > MAX_FID) {
590 printk(KERN_ERR FW_BUG PFX "maxfid exceeded with pstate"
591 " %d\n", j);
592 return -ENODEV;
594 if (j && (pst[j].fid < HI_FID_TABLE_BOTTOM)) {
595 /* Only first fid is allowed to be in "low" range */
596 printk(KERN_ERR FW_BUG PFX "two low fids - %d : "
597 "0x%x\n", j, pst[j].fid);
598 return -EINVAL;
600 if (pst[j].fid < lastfid)
601 lastfid = pst[j].fid;
603 if (lastfid & 1) {
604 printk(KERN_ERR FW_BUG PFX "lastfid invalid\n");
605 return -EINVAL;
607 if (lastfid > LO_FID_TABLE_TOP)
608 printk(KERN_INFO FW_BUG PFX
609 "first fid not from lo freq table\n");
611 return 0;
614 static void invalidate_entry(struct cpufreq_frequency_table *powernow_table,
615 unsigned int entry)
617 powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
620 static void print_basics(struct powernow_k8_data *data)
622 int j;
623 for (j = 0; j < data->numps; j++) {
624 if (data->powernow_table[j].frequency !=
625 CPUFREQ_ENTRY_INVALID) {
626 if (cpu_family == CPU_HW_PSTATE) {
627 printk(KERN_INFO PFX
628 " %d : pstate %d (%d MHz)\n", j,
629 data->powernow_table[j].index,
630 data->powernow_table[j].frequency/1000);
631 } else {
632 printk(KERN_INFO PFX
633 "fid 0x%x (%d MHz), vid 0x%x\n",
634 data->powernow_table[j].index & 0xff,
635 data->powernow_table[j].frequency/1000,
636 data->powernow_table[j].index >> 8);
640 if (data->batps)
641 printk(KERN_INFO PFX "Only %d pstates on battery\n",
642 data->batps);
645 static u32 freq_from_fid_did(u32 fid, u32 did)
647 u32 mhz = 0;
649 if (boot_cpu_data.x86 == 0x10)
650 mhz = (100 * (fid + 0x10)) >> did;
651 else if (boot_cpu_data.x86 == 0x11)
652 mhz = (100 * (fid + 8)) >> did;
653 else
654 BUG();
656 return mhz * 1000;
659 static int fill_powernow_table(struct powernow_k8_data *data,
660 struct pst_s *pst, u8 maxvid)
662 struct cpufreq_frequency_table *powernow_table;
663 unsigned int j;
665 if (data->batps) {
666 /* use ACPI support to get full speed on mains power */
667 printk(KERN_WARNING PFX
668 "Only %d pstates usable (use ACPI driver for full "
669 "range\n", data->batps);
670 data->numps = data->batps;
673 for (j = 1; j < data->numps; j++) {
674 if (pst[j-1].fid >= pst[j].fid) {
675 printk(KERN_ERR PFX "PST out of sequence\n");
676 return -EINVAL;
680 if (data->numps < 2) {
681 printk(KERN_ERR PFX "no p states to transition\n");
682 return -ENODEV;
685 if (check_pst_table(data, pst, maxvid))
686 return -EINVAL;
688 powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table)
689 * (data->numps + 1)), GFP_KERNEL);
690 if (!powernow_table) {
691 printk(KERN_ERR PFX "powernow_table memory alloc failure\n");
692 return -ENOMEM;
695 for (j = 0; j < data->numps; j++) {
696 int freq;
697 powernow_table[j].index = pst[j].fid; /* lower 8 bits */
698 powernow_table[j].index |= (pst[j].vid << 8); /* upper 8 bits */
699 freq = find_khz_freq_from_fid(pst[j].fid);
700 powernow_table[j].frequency = freq;
702 powernow_table[data->numps].frequency = CPUFREQ_TABLE_END;
703 powernow_table[data->numps].index = 0;
705 if (query_current_values_with_pending_wait(data)) {
706 kfree(powernow_table);
707 return -EIO;
710 pr_debug("cfid 0x%x, cvid 0x%x\n", data->currfid, data->currvid);
711 data->powernow_table = powernow_table;
712 if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
713 print_basics(data);
715 for (j = 0; j < data->numps; j++)
716 if ((pst[j].fid == data->currfid) &&
717 (pst[j].vid == data->currvid))
718 return 0;
720 pr_debug("currfid/vid do not match PST, ignoring\n");
721 return 0;
724 /* Find and validate the PSB/PST table in BIOS. */
725 static int find_psb_table(struct powernow_k8_data *data)
727 struct psb_s *psb;
728 unsigned int i;
729 u32 mvs;
730 u8 maxvid;
731 u32 cpst = 0;
732 u32 thiscpuid;
734 for (i = 0xc0000; i < 0xffff0; i += 0x10) {
735 /* Scan BIOS looking for the signature. */
736 /* It can not be at ffff0 - it is too big. */
738 psb = phys_to_virt(i);
739 if (memcmp(psb, PSB_ID_STRING, PSB_ID_STRING_LEN) != 0)
740 continue;
742 pr_debug("found PSB header at 0x%p\n", psb);
744 pr_debug("table vers: 0x%x\n", psb->tableversion);
745 if (psb->tableversion != PSB_VERSION_1_4) {
746 printk(KERN_ERR FW_BUG PFX "PSB table is not v1.4\n");
747 return -ENODEV;
750 pr_debug("flags: 0x%x\n", psb->flags1);
751 if (psb->flags1) {
752 printk(KERN_ERR FW_BUG PFX "unknown flags\n");
753 return -ENODEV;
756 data->vstable = psb->vstable;
757 pr_debug("voltage stabilization time: %d(*20us)\n",
758 data->vstable);
760 pr_debug("flags2: 0x%x\n", psb->flags2);
761 data->rvo = psb->flags2 & 3;
762 data->irt = ((psb->flags2) >> 2) & 3;
763 mvs = ((psb->flags2) >> 4) & 3;
764 data->vidmvs = 1 << mvs;
765 data->batps = ((psb->flags2) >> 6) & 3;
767 pr_debug("ramp voltage offset: %d\n", data->rvo);
768 pr_debug("isochronous relief time: %d\n", data->irt);
769 pr_debug("maximum voltage step: %d - 0x%x\n", mvs, data->vidmvs);
771 pr_debug("numpst: 0x%x\n", psb->num_tables);
772 cpst = psb->num_tables;
773 if ((psb->cpuid == 0x00000fc0) ||
774 (psb->cpuid == 0x00000fe0)) {
775 thiscpuid = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
776 if ((thiscpuid == 0x00000fc0) ||
777 (thiscpuid == 0x00000fe0))
778 cpst = 1;
780 if (cpst != 1) {
781 printk(KERN_ERR FW_BUG PFX "numpst must be 1\n");
782 return -ENODEV;
785 data->plllock = psb->plllocktime;
786 pr_debug("plllocktime: 0x%x (units 1us)\n", psb->plllocktime);
787 pr_debug("maxfid: 0x%x\n", psb->maxfid);
788 pr_debug("maxvid: 0x%x\n", psb->maxvid);
789 maxvid = psb->maxvid;
791 data->numps = psb->numps;
792 pr_debug("numpstates: 0x%x\n", data->numps);
793 return fill_powernow_table(data,
794 (struct pst_s *)(psb+1), maxvid);
797 * If you see this message, complain to BIOS manufacturer. If
798 * he tells you "we do not support Linux" or some similar
799 * nonsense, remember that Windows 2000 uses the same legacy
800 * mechanism that the old Linux PSB driver uses. Tell them it
801 * is broken with Windows 2000.
803 * The reference to the AMD documentation is chapter 9 in the
804 * BIOS and Kernel Developer's Guide, which is available on
805 * www.amd.com
807 printk(KERN_ERR FW_BUG PFX "No PSB or ACPI _PSS objects\n");
808 printk(KERN_ERR PFX "Make sure that your BIOS is up to date"
809 " and Cool'N'Quiet support is enabled in BIOS setup\n");
810 return -ENODEV;
813 static void powernow_k8_acpi_pst_values(struct powernow_k8_data *data,
814 unsigned int index)
816 u64 control;
818 if (!data->acpi_data.state_count || (cpu_family == CPU_HW_PSTATE))
819 return;
821 control = data->acpi_data.states[index].control;
822 data->irt = (control >> IRT_SHIFT) & IRT_MASK;
823 data->rvo = (control >> RVO_SHIFT) & RVO_MASK;
824 data->exttype = (control >> EXT_TYPE_SHIFT) & EXT_TYPE_MASK;
825 data->plllock = (control >> PLL_L_SHIFT) & PLL_L_MASK;
826 data->vidmvs = 1 << ((control >> MVS_SHIFT) & MVS_MASK);
827 data->vstable = (control >> VST_SHIFT) & VST_MASK;
830 static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
832 struct cpufreq_frequency_table *powernow_table;
833 int ret_val = -ENODEV;
834 u64 control, status;
836 if (acpi_processor_register_performance(&data->acpi_data, data->cpu)) {
837 pr_debug("register performance failed: bad ACPI data\n");
838 return -EIO;
841 /* verify the data contained in the ACPI structures */
842 if (data->acpi_data.state_count <= 1) {
843 pr_debug("No ACPI P-States\n");
844 goto err_out;
847 control = data->acpi_data.control_register.space_id;
848 status = data->acpi_data.status_register.space_id;
850 if ((control != ACPI_ADR_SPACE_FIXED_HARDWARE) ||
851 (status != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
852 pr_debug("Invalid control/status registers (%llx - %llx)\n",
853 control, status);
854 goto err_out;
857 /* fill in data->powernow_table */
858 powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table)
859 * (data->acpi_data.state_count + 1)), GFP_KERNEL);
860 if (!powernow_table) {
861 pr_debug("powernow_table memory alloc failure\n");
862 goto err_out;
865 /* fill in data */
866 data->numps = data->acpi_data.state_count;
867 powernow_k8_acpi_pst_values(data, 0);
869 if (cpu_family == CPU_HW_PSTATE)
870 ret_val = fill_powernow_table_pstate(data, powernow_table);
871 else
872 ret_val = fill_powernow_table_fidvid(data, powernow_table);
873 if (ret_val)
874 goto err_out_mem;
876 powernow_table[data->acpi_data.state_count].frequency =
877 CPUFREQ_TABLE_END;
878 powernow_table[data->acpi_data.state_count].index = 0;
879 data->powernow_table = powernow_table;
881 if (cpumask_first(cpu_core_mask(data->cpu)) == data->cpu)
882 print_basics(data);
884 /* notify BIOS that we exist */
885 acpi_processor_notify_smm(THIS_MODULE);
887 if (!zalloc_cpumask_var(&data->acpi_data.shared_cpu_map, GFP_KERNEL)) {
888 printk(KERN_ERR PFX
889 "unable to alloc powernow_k8_data cpumask\n");
890 ret_val = -ENOMEM;
891 goto err_out_mem;
894 return 0;
896 err_out_mem:
897 kfree(powernow_table);
899 err_out:
900 acpi_processor_unregister_performance(&data->acpi_data, data->cpu);
902 /* data->acpi_data.state_count informs us at ->exit()
903 * whether ACPI was used */
904 data->acpi_data.state_count = 0;
906 return ret_val;
909 static int fill_powernow_table_pstate(struct powernow_k8_data *data,
910 struct cpufreq_frequency_table *powernow_table)
912 int i;
913 u32 hi = 0, lo = 0;
914 rdmsr(MSR_PSTATE_CUR_LIMIT, lo, hi);
915 data->max_hw_pstate = (lo & HW_PSTATE_MAX_MASK) >> HW_PSTATE_MAX_SHIFT;
917 for (i = 0; i < data->acpi_data.state_count; i++) {
918 u32 index;
920 index = data->acpi_data.states[i].control & HW_PSTATE_MASK;
921 if (index > data->max_hw_pstate) {
922 printk(KERN_ERR PFX "invalid pstate %d - "
923 "bad value %d.\n", i, index);
924 printk(KERN_ERR PFX "Please report to BIOS "
925 "manufacturer\n");
926 invalidate_entry(powernow_table, i);
927 continue;
929 rdmsr(MSR_PSTATE_DEF_BASE + index, lo, hi);
930 if (!(hi & HW_PSTATE_VALID_MASK)) {
931 pr_debug("invalid pstate %d, ignoring\n", index);
932 invalidate_entry(powernow_table, i);
933 continue;
936 powernow_table[i].index = index;
938 /* Frequency may be rounded for these */
939 if ((boot_cpu_data.x86 == 0x10 && boot_cpu_data.x86_model < 10)
940 || boot_cpu_data.x86 == 0x11) {
941 powernow_table[i].frequency =
942 freq_from_fid_did(lo & 0x3f, (lo >> 6) & 7);
943 } else
944 powernow_table[i].frequency =
945 data->acpi_data.states[i].core_frequency * 1000;
947 return 0;
950 static int fill_powernow_table_fidvid(struct powernow_k8_data *data,
951 struct cpufreq_frequency_table *powernow_table)
953 int i;
955 for (i = 0; i < data->acpi_data.state_count; i++) {
956 u32 fid;
957 u32 vid;
958 u32 freq, index;
959 u64 status, control;
961 if (data->exttype) {
962 status = data->acpi_data.states[i].status;
963 fid = status & EXT_FID_MASK;
964 vid = (status >> VID_SHIFT) & EXT_VID_MASK;
965 } else {
966 control = data->acpi_data.states[i].control;
967 fid = control & FID_MASK;
968 vid = (control >> VID_SHIFT) & VID_MASK;
971 pr_debug(" %d : fid 0x%x, vid 0x%x\n", i, fid, vid);
973 index = fid | (vid<<8);
974 powernow_table[i].index = index;
976 freq = find_khz_freq_from_fid(fid);
977 powernow_table[i].frequency = freq;
979 /* verify frequency is OK */
980 if ((freq > (MAX_FREQ * 1000)) || (freq < (MIN_FREQ * 1000))) {
981 pr_debug("invalid freq %u kHz, ignoring\n", freq);
982 invalidate_entry(powernow_table, i);
983 continue;
986 /* verify voltage is OK -
987 * BIOSs are using "off" to indicate invalid */
988 if (vid == VID_OFF) {
989 pr_debug("invalid vid %u, ignoring\n", vid);
990 invalidate_entry(powernow_table, i);
991 continue;
994 if (freq != (data->acpi_data.states[i].core_frequency * 1000)) {
995 printk(KERN_INFO PFX "invalid freq entries "
996 "%u kHz vs. %u kHz\n", freq,
997 (unsigned int)
998 (data->acpi_data.states[i].core_frequency
999 * 1000));
1000 invalidate_entry(powernow_table, i);
1001 continue;
1004 return 0;
1007 static void powernow_k8_cpu_exit_acpi(struct powernow_k8_data *data)
1009 if (data->acpi_data.state_count)
1010 acpi_processor_unregister_performance(&data->acpi_data,
1011 data->cpu);
1012 free_cpumask_var(data->acpi_data.shared_cpu_map);
1015 static int get_transition_latency(struct powernow_k8_data *data)
1017 int max_latency = 0;
1018 int i;
1019 for (i = 0; i < data->acpi_data.state_count; i++) {
1020 int cur_latency = data->acpi_data.states[i].transition_latency
1021 + data->acpi_data.states[i].bus_master_latency;
1022 if (cur_latency > max_latency)
1023 max_latency = cur_latency;
1025 if (max_latency == 0) {
1027 * Fam 11h and later may return 0 as transition latency. This
1028 * is intended and means "very fast". While cpufreq core and
1029 * governors currently can handle that gracefully, better set it
1030 * to 1 to avoid problems in the future.
1032 if (boot_cpu_data.x86 < 0x11)
1033 printk(KERN_ERR FW_WARN PFX "Invalid zero transition "
1034 "latency\n");
1035 max_latency = 1;
1037 /* value in usecs, needs to be in nanoseconds */
1038 return 1000 * max_latency;
1041 /* Take a frequency, and issue the fid/vid transition command */
1042 static int transition_frequency_fidvid(struct powernow_k8_data *data,
1043 unsigned int index)
1045 u32 fid = 0;
1046 u32 vid = 0;
1047 int res, i;
1048 struct cpufreq_freqs freqs;
1050 pr_debug("cpu %d transition to index %u\n", smp_processor_id(), index);
1052 /* fid/vid correctness check for k8 */
1053 /* fid are the lower 8 bits of the index we stored into
1054 * the cpufreq frequency table in find_psb_table, vid
1055 * are the upper 8 bits.
1057 fid = data->powernow_table[index].index & 0xFF;
1058 vid = (data->powernow_table[index].index & 0xFF00) >> 8;
1060 pr_debug("table matched fid 0x%x, giving vid 0x%x\n", fid, vid);
1062 if (query_current_values_with_pending_wait(data))
1063 return 1;
1065 if ((data->currvid == vid) && (data->currfid == fid)) {
1066 pr_debug("target matches current values (fid 0x%x, vid 0x%x)\n",
1067 fid, vid);
1068 return 0;
1071 pr_debug("cpu %d, changing to fid 0x%x, vid 0x%x\n",
1072 smp_processor_id(), fid, vid);
1073 freqs.old = find_khz_freq_from_fid(data->currfid);
1074 freqs.new = find_khz_freq_from_fid(fid);
1076 for_each_cpu(i, data->available_cores) {
1077 freqs.cpu = i;
1078 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
1081 res = transition_fid_vid(data, fid, vid);
1082 if (res)
1083 return res;
1085 freqs.new = find_khz_freq_from_fid(data->currfid);
1087 for_each_cpu(i, data->available_cores) {
1088 freqs.cpu = i;
1089 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
1091 return res;
1094 /* Take a frequency, and issue the hardware pstate transition command */
1095 static int transition_frequency_pstate(struct powernow_k8_data *data,
1096 unsigned int index)
1098 u32 pstate = 0;
1099 int res, i;
1100 struct cpufreq_freqs freqs;
1102 pr_debug("cpu %d transition to index %u\n", smp_processor_id(), index);
1104 /* get MSR index for hardware pstate transition */
1105 pstate = index & HW_PSTATE_MASK;
1106 if (pstate > data->max_hw_pstate)
1107 return -EINVAL;
1109 freqs.old = find_khz_freq_from_pstate(data->powernow_table,
1110 data->currpstate);
1111 freqs.new = find_khz_freq_from_pstate(data->powernow_table, pstate);
1113 for_each_cpu(i, data->available_cores) {
1114 freqs.cpu = i;
1115 cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE);
1118 res = transition_pstate(data, pstate);
1119 freqs.new = find_khz_freq_from_pstate(data->powernow_table, pstate);
1121 for_each_cpu(i, data->available_cores) {
1122 freqs.cpu = i;
1123 cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE);
1125 return res;
1128 /* Driver entry point to switch to the target frequency */
1129 static int powernowk8_target(struct cpufreq_policy *pol,
1130 unsigned targfreq, unsigned relation)
1132 cpumask_var_t oldmask;
1133 struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1134 u32 checkfid;
1135 u32 checkvid;
1136 unsigned int newstate;
1137 int ret = -EIO;
1139 if (!data)
1140 return -EINVAL;
1142 checkfid = data->currfid;
1143 checkvid = data->currvid;
1145 /* only run on specific CPU from here on. */
1146 /* This is poor form: use a workqueue or smp_call_function_single */
1147 if (!alloc_cpumask_var(&oldmask, GFP_KERNEL))
1148 return -ENOMEM;
1150 cpumask_copy(oldmask, tsk_cpus_allowed(current));
1151 set_cpus_allowed_ptr(current, cpumask_of(pol->cpu));
1153 if (smp_processor_id() != pol->cpu) {
1154 printk(KERN_ERR PFX "limiting to cpu %u failed\n", pol->cpu);
1155 goto err_out;
1158 if (pending_bit_stuck()) {
1159 printk(KERN_ERR PFX "failing targ, change pending bit set\n");
1160 goto err_out;
1163 pr_debug("targ: cpu %d, %d kHz, min %d, max %d, relation %d\n",
1164 pol->cpu, targfreq, pol->min, pol->max, relation);
1166 if (query_current_values_with_pending_wait(data))
1167 goto err_out;
1169 if (cpu_family != CPU_HW_PSTATE) {
1170 pr_debug("targ: curr fid 0x%x, vid 0x%x\n",
1171 data->currfid, data->currvid);
1173 if ((checkvid != data->currvid) ||
1174 (checkfid != data->currfid)) {
1175 printk(KERN_INFO PFX
1176 "error - out of sync, fix 0x%x 0x%x, "
1177 "vid 0x%x 0x%x\n",
1178 checkfid, data->currfid,
1179 checkvid, data->currvid);
1183 if (cpufreq_frequency_table_target(pol, data->powernow_table,
1184 targfreq, relation, &newstate))
1185 goto err_out;
1187 mutex_lock(&fidvid_mutex);
1189 powernow_k8_acpi_pst_values(data, newstate);
1191 if (cpu_family == CPU_HW_PSTATE)
1192 ret = transition_frequency_pstate(data, newstate);
1193 else
1194 ret = transition_frequency_fidvid(data, newstate);
1195 if (ret) {
1196 printk(KERN_ERR PFX "transition frequency failed\n");
1197 ret = 1;
1198 mutex_unlock(&fidvid_mutex);
1199 goto err_out;
1201 mutex_unlock(&fidvid_mutex);
1203 if (cpu_family == CPU_HW_PSTATE)
1204 pol->cur = find_khz_freq_from_pstate(data->powernow_table,
1205 newstate);
1206 else
1207 pol->cur = find_khz_freq_from_fid(data->currfid);
1208 ret = 0;
1210 err_out:
1211 set_cpus_allowed_ptr(current, oldmask);
1212 free_cpumask_var(oldmask);
1213 return ret;
1216 /* Driver entry point to verify the policy and range of frequencies */
1217 static int powernowk8_verify(struct cpufreq_policy *pol)
1219 struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1221 if (!data)
1222 return -EINVAL;
1224 return cpufreq_frequency_table_verify(pol, data->powernow_table);
1227 struct init_on_cpu {
1228 struct powernow_k8_data *data;
1229 int rc;
1232 static void __cpuinit powernowk8_cpu_init_on_cpu(void *_init_on_cpu)
1234 struct init_on_cpu *init_on_cpu = _init_on_cpu;
1236 if (pending_bit_stuck()) {
1237 printk(KERN_ERR PFX "failing init, change pending bit set\n");
1238 init_on_cpu->rc = -ENODEV;
1239 return;
1242 if (query_current_values_with_pending_wait(init_on_cpu->data)) {
1243 init_on_cpu->rc = -ENODEV;
1244 return;
1247 if (cpu_family == CPU_OPTERON)
1248 fidvid_msr_init();
1250 init_on_cpu->rc = 0;
1253 /* per CPU init entry point to the driver */
1254 static int __cpuinit powernowk8_cpu_init(struct cpufreq_policy *pol)
1256 static const char ACPI_PSS_BIOS_BUG_MSG[] =
1257 KERN_ERR FW_BUG PFX "No compatible ACPI _PSS objects found.\n"
1258 FW_BUG PFX "Try again with latest BIOS.\n";
1259 struct powernow_k8_data *data;
1260 struct init_on_cpu init_on_cpu;
1261 int rc;
1262 struct cpuinfo_x86 *c = &cpu_data(pol->cpu);
1264 if (!cpu_online(pol->cpu))
1265 return -ENODEV;
1267 smp_call_function_single(pol->cpu, check_supported_cpu, &rc, 1);
1268 if (rc)
1269 return -ENODEV;
1271 data = kzalloc(sizeof(struct powernow_k8_data), GFP_KERNEL);
1272 if (!data) {
1273 printk(KERN_ERR PFX "unable to alloc powernow_k8_data");
1274 return -ENOMEM;
1277 data->cpu = pol->cpu;
1278 data->currpstate = HW_PSTATE_INVALID;
1280 if (powernow_k8_cpu_init_acpi(data)) {
1282 * Use the PSB BIOS structure. This is only available on
1283 * an UP version, and is deprecated by AMD.
1285 if (num_online_cpus() != 1) {
1286 printk_once(ACPI_PSS_BIOS_BUG_MSG);
1287 goto err_out;
1289 if (pol->cpu != 0) {
1290 printk(KERN_ERR FW_BUG PFX "No ACPI _PSS objects for "
1291 "CPU other than CPU0. Complain to your BIOS "
1292 "vendor.\n");
1293 goto err_out;
1295 rc = find_psb_table(data);
1296 if (rc)
1297 goto err_out;
1299 /* Take a crude guess here.
1300 * That guess was in microseconds, so multiply with 1000 */
1301 pol->cpuinfo.transition_latency = (
1302 ((data->rvo + 8) * data->vstable * VST_UNITS_20US) +
1303 ((1 << data->irt) * 30)) * 1000;
1304 } else /* ACPI _PSS objects available */
1305 pol->cpuinfo.transition_latency = get_transition_latency(data);
1307 /* only run on specific CPU from here on */
1308 init_on_cpu.data = data;
1309 smp_call_function_single(data->cpu, powernowk8_cpu_init_on_cpu,
1310 &init_on_cpu, 1);
1311 rc = init_on_cpu.rc;
1312 if (rc != 0)
1313 goto err_out_exit_acpi;
1315 if (cpu_family == CPU_HW_PSTATE)
1316 cpumask_copy(pol->cpus, cpumask_of(pol->cpu));
1317 else
1318 cpumask_copy(pol->cpus, cpu_core_mask(pol->cpu));
1319 data->available_cores = pol->cpus;
1321 if (cpu_family == CPU_HW_PSTATE)
1322 pol->cur = find_khz_freq_from_pstate(data->powernow_table,
1323 data->currpstate);
1324 else
1325 pol->cur = find_khz_freq_from_fid(data->currfid);
1326 pr_debug("policy current frequency %d kHz\n", pol->cur);
1328 /* min/max the cpu is capable of */
1329 if (cpufreq_frequency_table_cpuinfo(pol, data->powernow_table)) {
1330 printk(KERN_ERR FW_BUG PFX "invalid powernow_table\n");
1331 powernow_k8_cpu_exit_acpi(data);
1332 kfree(data->powernow_table);
1333 kfree(data);
1334 return -EINVAL;
1337 /* Check for APERF/MPERF support in hardware */
1338 if (cpu_has(c, X86_FEATURE_APERFMPERF))
1339 cpufreq_amd64_driver.getavg = cpufreq_get_measured_perf;
1341 cpufreq_frequency_table_get_attr(data->powernow_table, pol->cpu);
1343 if (cpu_family == CPU_HW_PSTATE)
1344 pr_debug("cpu_init done, current pstate 0x%x\n",
1345 data->currpstate);
1346 else
1347 pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n",
1348 data->currfid, data->currvid);
1350 per_cpu(powernow_data, pol->cpu) = data;
1352 return 0;
1354 err_out_exit_acpi:
1355 powernow_k8_cpu_exit_acpi(data);
1357 err_out:
1358 kfree(data);
1359 return -ENODEV;
1362 static int __devexit powernowk8_cpu_exit(struct cpufreq_policy *pol)
1364 struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1366 if (!data)
1367 return -EINVAL;
1369 powernow_k8_cpu_exit_acpi(data);
1371 cpufreq_frequency_table_put_attr(pol->cpu);
1373 kfree(data->powernow_table);
1374 kfree(data);
1375 per_cpu(powernow_data, pol->cpu) = NULL;
1377 return 0;
1380 static void query_values_on_cpu(void *_err)
1382 int *err = _err;
1383 struct powernow_k8_data *data = __this_cpu_read(powernow_data);
1385 *err = query_current_values_with_pending_wait(data);
1388 static unsigned int powernowk8_get(unsigned int cpu)
1390 struct powernow_k8_data *data = per_cpu(powernow_data, cpu);
1391 unsigned int khz = 0;
1392 int err;
1394 if (!data)
1395 return 0;
1397 smp_call_function_single(cpu, query_values_on_cpu, &err, true);
1398 if (err)
1399 goto out;
1401 if (cpu_family == CPU_HW_PSTATE)
1402 khz = find_khz_freq_from_pstate(data->powernow_table,
1403 data->currpstate);
1404 else
1405 khz = find_khz_freq_from_fid(data->currfid);
1408 out:
1409 return khz;
1412 static void _cpb_toggle_msrs(bool t)
1414 int cpu;
1416 get_online_cpus();
1418 rdmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
1420 for_each_cpu(cpu, cpu_online_mask) {
1421 struct msr *reg = per_cpu_ptr(msrs, cpu);
1422 if (t)
1423 reg->l &= ~BIT(25);
1424 else
1425 reg->l |= BIT(25);
1427 wrmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
1429 put_online_cpus();
1433 * Switch on/off core performance boosting.
1435 * 0=disable
1436 * 1=enable.
1438 static void cpb_toggle(bool t)
1440 if (!cpb_capable)
1441 return;
1443 if (t && !cpb_enabled) {
1444 cpb_enabled = true;
1445 _cpb_toggle_msrs(t);
1446 printk(KERN_INFO PFX "Core Boosting enabled.\n");
1447 } else if (!t && cpb_enabled) {
1448 cpb_enabled = false;
1449 _cpb_toggle_msrs(t);
1450 printk(KERN_INFO PFX "Core Boosting disabled.\n");
1454 static ssize_t store_cpb(struct cpufreq_policy *policy, const char *buf,
1455 size_t count)
1457 int ret = -EINVAL;
1458 unsigned long val = 0;
1460 ret = strict_strtoul(buf, 10, &val);
1461 if (!ret && (val == 0 || val == 1) && cpb_capable)
1462 cpb_toggle(val);
1463 else
1464 return -EINVAL;
1466 return count;
1469 static ssize_t show_cpb(struct cpufreq_policy *policy, char *buf)
1471 return sprintf(buf, "%u\n", cpb_enabled);
1474 #define define_one_rw(_name) \
1475 static struct freq_attr _name = \
1476 __ATTR(_name, 0644, show_##_name, store_##_name)
1478 define_one_rw(cpb);
1480 static struct freq_attr *powernow_k8_attr[] = {
1481 &cpufreq_freq_attr_scaling_available_freqs,
1482 &cpb,
1483 NULL,
1486 static struct cpufreq_driver cpufreq_amd64_driver = {
1487 .verify = powernowk8_verify,
1488 .target = powernowk8_target,
1489 .bios_limit = acpi_processor_get_bios_limit,
1490 .init = powernowk8_cpu_init,
1491 .exit = __devexit_p(powernowk8_cpu_exit),
1492 .get = powernowk8_get,
1493 .name = "powernow-k8",
1494 .owner = THIS_MODULE,
1495 .attr = powernow_k8_attr,
1499 * Clear the boost-disable flag on the CPU_DOWN path so that this cpu
1500 * cannot block the remaining ones from boosting. On the CPU_UP path we
1501 * simply keep the boost-disable flag in sync with the current global
1502 * state.
1504 static int cpb_notify(struct notifier_block *nb, unsigned long action,
1505 void *hcpu)
1507 unsigned cpu = (long)hcpu;
1508 u32 lo, hi;
1510 switch (action) {
1511 case CPU_UP_PREPARE:
1512 case CPU_UP_PREPARE_FROZEN:
1514 if (!cpb_enabled) {
1515 rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
1516 lo |= BIT(25);
1517 wrmsr_on_cpu(cpu, MSR_K7_HWCR, lo, hi);
1519 break;
1521 case CPU_DOWN_PREPARE:
1522 case CPU_DOWN_PREPARE_FROZEN:
1523 rdmsr_on_cpu(cpu, MSR_K7_HWCR, &lo, &hi);
1524 lo &= ~BIT(25);
1525 wrmsr_on_cpu(cpu, MSR_K7_HWCR, lo, hi);
1526 break;
1528 default:
1529 break;
1532 return NOTIFY_OK;
1535 static struct notifier_block cpb_nb = {
1536 .notifier_call = cpb_notify,
1539 /* driver entry point for init */
1540 static int __cpuinit powernowk8_init(void)
1542 unsigned int i, supported_cpus = 0, cpu;
1543 int rv;
1545 for_each_online_cpu(i) {
1546 int rc;
1547 smp_call_function_single(i, check_supported_cpu, &rc, 1);
1548 if (rc == 0)
1549 supported_cpus++;
1552 if (supported_cpus != num_online_cpus())
1553 return -ENODEV;
1555 printk(KERN_INFO PFX "Found %d %s (%d cpu cores) (" VERSION ")\n",
1556 num_online_nodes(), boot_cpu_data.x86_model_id, supported_cpus);
1558 if (boot_cpu_has(X86_FEATURE_CPB)) {
1560 cpb_capable = true;
1562 msrs = msrs_alloc();
1563 if (!msrs) {
1564 printk(KERN_ERR "%s: Error allocating msrs!\n", __func__);
1565 return -ENOMEM;
1568 register_cpu_notifier(&cpb_nb);
1570 rdmsr_on_cpus(cpu_online_mask, MSR_K7_HWCR, msrs);
1572 for_each_cpu(cpu, cpu_online_mask) {
1573 struct msr *reg = per_cpu_ptr(msrs, cpu);
1574 cpb_enabled |= !(!!(reg->l & BIT(25)));
1577 printk(KERN_INFO PFX "Core Performance Boosting: %s.\n",
1578 (cpb_enabled ? "on" : "off"));
1581 rv = cpufreq_register_driver(&cpufreq_amd64_driver);
1582 if (rv < 0 && boot_cpu_has(X86_FEATURE_CPB)) {
1583 unregister_cpu_notifier(&cpb_nb);
1584 msrs_free(msrs);
1585 msrs = NULL;
1587 return rv;
1590 /* driver entry point for term */
1591 static void __exit powernowk8_exit(void)
1593 pr_debug("exit\n");
1595 if (boot_cpu_has(X86_FEATURE_CPB)) {
1596 msrs_free(msrs);
1597 msrs = NULL;
1599 unregister_cpu_notifier(&cpb_nb);
1602 cpufreq_unregister_driver(&cpufreq_amd64_driver);
1605 MODULE_AUTHOR("Paul Devriendt <paul.devriendt@amd.com> and "
1606 "Mark Langsdorf <mark.langsdorf@amd.com>");
1607 MODULE_DESCRIPTION("AMD Athlon 64 and Opteron processor frequency driver.");
1608 MODULE_LICENSE("GPL");
1610 late_initcall(powernowk8_init);
1611 module_exit(powernowk8_exit);