1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * (c) 2003-2012 Advanced Micro Devices, Inc.
4 *
5 * Maintainer:
6 * Andreas Herrmann <herrmann.der.user@googlemail.com>
7 *
8 * Based on the powernow-k7.c module written by Dave Jones.
9 * (C) 2003 Dave Jones on behalf of SuSE Labs
10 * (C) 2004 Dominik Brodowski <linux@brodo.de>
11 * (C) 2004 Pavel Machek <pavel@ucw.cz>
12 * Based upon datasheets & sample CPUs kindly provided by AMD.
13 *
14 * Valuable input gratefully received from Dave Jones, Pavel Machek,
15 * Dominik Brodowski, Jacob Shin, and others.
16 * Originally developed by Paul Devriendt.
17 *
18 * Processor information obtained from Chapter 9 (Power and Thermal
19 * Management) of the "BIOS and Kernel Developer's Guide (BKDG) for
20 * the AMD Athlon 64 and AMD Opteron Processors" and section "2.x
21 * Power Management" in BKDGs for newer AMD CPU families.
22 *
23 * Tables for specific CPUs can be inferred from AMD's processor
24 * power and thermal data sheets, (e.g. 30417.pdf, 30430.pdf, 43375.pdf)
25 */
26
27#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
28
29#include <linux/kernel.h>
30#include <linux/smp.h>
31#include <linux/module.h>
32#include <linux/init.h>
33#include <linux/cpufreq.h>
34#include <linux/slab.h>
35#include <linux/string.h>
36#include <linux/cpumask.h>
37#include <linux/io.h>
38#include <linux/delay.h>
39
40#include <asm/msr.h>
41#include <asm/cpu_device_id.h>
42
43#include <linux/acpi.h>
44#include <linux/mutex.h>
45#include <acpi/processor.h>
46
47#define VERSION "version 2.20.00"
48#include "powernow-k8.h"
49
50/* serialize freq changes */
51static DEFINE_MUTEX(fidvid_mutex);
52
53static DEFINE_PER_CPU(struct powernow_k8_data *, powernow_data);
54
55static struct cpufreq_driver cpufreq_amd64_driver;
56
57/* Return a frequency in MHz, given an input fid */
58static u32 find_freq_from_fid(u32 fid)
59{
60 return 800 + (fid * 100);
61}
62
63/* Return a frequency in KHz, given an input fid */
64static u32 find_khz_freq_from_fid(u32 fid)
65{
66 return 1000 * find_freq_from_fid(fid);
67}
68
69/* Return the vco fid for an input fid
70 *
71 * Each "low" fid has corresponding "high" fid, and you can get to "low" fids
72 * only from corresponding high fids. This returns "high" fid corresponding to
73 * "low" one.
74 */
75static u32 convert_fid_to_vco_fid(u32 fid)
76{
77 if (fid < HI_FID_TABLE_BOTTOM)
78 return 8 + (2 * fid);
79 else
80 return fid;
81}
82
83/*
84 * Return 1 if the pending bit is set. Unless we just instructed the processor
85 * to transition to a new state, seeing this bit set is really bad news.
86 */
87static int pending_bit_stuck(void)
88{
89 u32 lo, hi __always_unused;
90
91 rdmsr(MSR_FIDVID_STATUS, lo, hi);
92 return lo & MSR_S_LO_CHANGE_PENDING ? 1 : 0;
93}
94
95/*
96 * Update the global current fid / vid values from the status msr.
97 * Returns 1 on error.
98 */
99static int query_current_values_with_pending_wait(struct powernow_k8_data *data)
100{
101 u32 lo, hi;
102 u32 i = 0;
103
104 do {
105 if (i++ > 10000) {
106 pr_debug("detected change pending stuck\n");
107 return 1;
108 }
109 rdmsr(MSR_FIDVID_STATUS, lo, hi);
110 } while (lo & MSR_S_LO_CHANGE_PENDING);
111
112 data->currvid = hi & MSR_S_HI_CURRENT_VID;
113 data->currfid = lo & MSR_S_LO_CURRENT_FID;
114
115 return 0;
116}
117
118/* the isochronous relief time */
119static void count_off_irt(struct powernow_k8_data *data)
120{
121 udelay((1 << data->irt) * 10);
122}
123
124/* the voltage stabilization time */
125static void count_off_vst(struct powernow_k8_data *data)
126{
127 udelay(data->vstable * VST_UNITS_20US);
128}
129
130/* need to init the control msr to a safe value (for each cpu) */
131static void fidvid_msr_init(void)
132{
133 u32 lo, hi;
134 u8 fid, vid;
135
136 rdmsr(MSR_FIDVID_STATUS, lo, hi);
137 vid = hi & MSR_S_HI_CURRENT_VID;
138 fid = lo & MSR_S_LO_CURRENT_FID;
139 lo = fid | (vid << MSR_C_LO_VID_SHIFT);
140 hi = MSR_C_HI_STP_GNT_BENIGN;
141 pr_debug("cpu%d, init lo 0x%x, hi 0x%x\n", smp_processor_id(), lo, hi);
142 wrmsr(MSR_FIDVID_CTL, lo, hi);
143}
144
145/* write the new fid value along with the other control fields to the msr */
146static int write_new_fid(struct powernow_k8_data *data, u32 fid)
147{
148 u32 lo;
149 u32 savevid = data->currvid;
150 u32 i = 0;
151
152 if ((fid & INVALID_FID_MASK) || (data->currvid & INVALID_VID_MASK)) {
153 pr_err("internal error - overflow on fid write\n");
154 return 1;
155 }
156
157 lo = fid;
158 lo |= (data->currvid << MSR_C_LO_VID_SHIFT);
159 lo |= MSR_C_LO_INIT_FID_VID;
160
161 pr_debug("writing fid 0x%x, lo 0x%x, hi 0x%x\n",
162 fid, lo, data->plllock * PLL_LOCK_CONVERSION);
163
164 do {
165 wrmsr(MSR_FIDVID_CTL, lo, data->plllock * PLL_LOCK_CONVERSION);
166 if (i++ > 100) {
167 pr_err("Hardware error - pending bit very stuck - no further pstate changes possible\n");
168 return 1;
169 }
170 } while (query_current_values_with_pending_wait(data));
171
172 count_off_irt(data);
173
174 if (savevid != data->currvid) {
175 pr_err("vid change on fid trans, old 0x%x, new 0x%x\n",
176 savevid, data->currvid);
177 return 1;
178 }
179
180 if (fid != data->currfid) {
181 pr_err("fid trans failed, fid 0x%x, curr 0x%x\n", fid,
182 data->currfid);
183 return 1;
184 }
185
186 return 0;
187}
188
189/* Write a new vid to the hardware */
190static int write_new_vid(struct powernow_k8_data *data, u32 vid)
191{
192 u32 lo;
193 u32 savefid = data->currfid;
194 int i = 0;
195
196 if ((data->currfid & INVALID_FID_MASK) || (vid & INVALID_VID_MASK)) {
197 pr_err("internal error - overflow on vid write\n");
198 return 1;
199 }
200
201 lo = data->currfid;
202 lo |= (vid << MSR_C_LO_VID_SHIFT);
203 lo |= MSR_C_LO_INIT_FID_VID;
204
205 pr_debug("writing vid 0x%x, lo 0x%x, hi 0x%x\n",
206 vid, lo, STOP_GRANT_5NS);
207
208 do {
209 wrmsr(MSR_FIDVID_CTL, lo, STOP_GRANT_5NS);
210 if (i++ > 100) {
211 pr_err("internal error - pending bit very stuck - no further pstate changes possible\n");
212 return 1;
213 }
214 } while (query_current_values_with_pending_wait(data));
215
216 if (savefid != data->currfid) {
217 pr_err("fid changed on vid trans, old 0x%x new 0x%x\n",
218 savefid, data->currfid);
219 return 1;
220 }
221
222 if (vid != data->currvid) {
223 pr_err("vid trans failed, vid 0x%x, curr 0x%x\n",
224 vid, data->currvid);
225 return 1;
226 }
227
228 return 0;
229}
230
231/*
232 * Reduce the vid by the max of step or reqvid.
233 * Decreasing vid codes represent increasing voltages:
234 * vid of 0 is 1.550V, vid of 0x1e is 0.800V, vid of VID_OFF is off.
235 */
236static int decrease_vid_code_by_step(struct powernow_k8_data *data,
237 u32 reqvid, u32 step)
238{
239 if ((data->currvid - reqvid) > step)
240 reqvid = data->currvid - step;
241
242 if (write_new_vid(data, vid: reqvid))
243 return 1;
244
245 count_off_vst(data);
246
247 return 0;
248}
249
250/* Change Opteron/Athlon64 fid and vid, by the 3 phases. */
251static int transition_fid_vid(struct powernow_k8_data *data,
252 u32 reqfid, u32 reqvid)
253{
254 if (core_voltage_pre_transition(data, reqvid, regfid: reqfid))
255 return 1;
256
257 if (core_frequency_transition(data, reqfid))
258 return 1;
259
260 if (core_voltage_post_transition(data, reqvid))
261 return 1;
262
263 if (query_current_values_with_pending_wait(data))
264 return 1;
265
266 if ((reqfid != data->currfid) || (reqvid != data->currvid)) {
267 pr_err("failed (cpu%d): req 0x%x 0x%x, curr 0x%x 0x%x\n",
268 smp_processor_id(),
269 reqfid, reqvid, data->currfid, data->currvid);
270 return 1;
271 }
272
273 pr_debug("transitioned (cpu%d): new fid 0x%x, vid 0x%x\n",
274 smp_processor_id(), data->currfid, data->currvid);
275
276 return 0;
277}
278
279/* Phase 1 - core voltage transition ... setup voltage */
280static int core_voltage_pre_transition(struct powernow_k8_data *data,
281 u32 reqvid, u32 reqfid)
282{
283 u32 rvosteps = data->rvo;
284 u32 savefid = data->currfid;
285 u32 maxvid, lo __always_unused, rvomult = 1;
286
287 pr_debug("ph1 (cpu%d): start, currfid 0x%x, currvid 0x%x, reqvid 0x%x, rvo 0x%x\n",
288 smp_processor_id(),
289 data->currfid, data->currvid, reqvid, data->rvo);
290
291 if ((savefid < LO_FID_TABLE_TOP) && (reqfid < LO_FID_TABLE_TOP))
292 rvomult = 2;
293 rvosteps *= rvomult;
294 rdmsr(MSR_FIDVID_STATUS, lo, maxvid);
295 maxvid = 0x1f & (maxvid >> 16);
296 pr_debug("ph1 maxvid=0x%x\n", maxvid);
297 if (reqvid < maxvid) /* lower numbers are higher voltages */
298 reqvid = maxvid;
299
300 while (data->currvid > reqvid) {
301 pr_debug("ph1: curr 0x%x, req vid 0x%x\n",
302 data->currvid, reqvid);
303 if (decrease_vid_code_by_step(data, reqvid, step: data->vidmvs))
304 return 1;
305 }
306
307 while ((rvosteps > 0) &&
308 ((rvomult * data->rvo + data->currvid) > reqvid)) {
309 if (data->currvid == maxvid) {
310 rvosteps = 0;
311 } else {
312 pr_debug("ph1: changing vid for rvo, req 0x%x\n",
313 data->currvid - 1);
314 if (decrease_vid_code_by_step(data, reqvid: data->currvid-1, step: 1))
315 return 1;
316 rvosteps--;
317 }
318 }
319
320 if (query_current_values_with_pending_wait(data))
321 return 1;
322
323 if (savefid != data->currfid) {
324 pr_err("ph1 err, currfid changed 0x%x\n", data->currfid);
325 return 1;
326 }
327
328 pr_debug("ph1 complete, currfid 0x%x, currvid 0x%x\n",
329 data->currfid, data->currvid);
330
331 return 0;
332}
333
334/* Phase 2 - core frequency transition */
335static int core_frequency_transition(struct powernow_k8_data *data, u32 reqfid)
336{
337 u32 vcoreqfid, vcocurrfid, vcofiddiff;
338 u32 fid_interval, savevid = data->currvid;
339
340 if (data->currfid == reqfid) {
341 pr_err("ph2 null fid transition 0x%x\n", data->currfid);
342 return 0;
343 }
344
345 pr_debug("ph2 (cpu%d): starting, currfid 0x%x, currvid 0x%x, reqfid 0x%x\n",
346 smp_processor_id(),
347 data->currfid, data->currvid, reqfid);
348
349 vcoreqfid = convert_fid_to_vco_fid(fid: reqfid);
350 vcocurrfid = convert_fid_to_vco_fid(fid: data->currfid);
351 vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
352 : vcoreqfid - vcocurrfid;
353
354 if ((reqfid <= LO_FID_TABLE_TOP) && (data->currfid <= LO_FID_TABLE_TOP))
355 vcofiddiff = 0;
356
357 while (vcofiddiff > 2) {
358 (data->currfid & 1) ? (fid_interval = 1) : (fid_interval = 2);
359
360 if (reqfid > data->currfid) {
361 if (data->currfid > LO_FID_TABLE_TOP) {
362 if (write_new_fid(data,
363 fid: data->currfid + fid_interval))
364 return 1;
365 } else {
366 if (write_new_fid
367 (data,
368 fid: 2 + convert_fid_to_vco_fid(fid: data->currfid)))
369 return 1;
370 }
371 } else {
372 if (write_new_fid(data, fid: data->currfid - fid_interval))
373 return 1;
374 }
375
376 vcocurrfid = convert_fid_to_vco_fid(fid: data->currfid);
377 vcofiddiff = vcocurrfid > vcoreqfid ? vcocurrfid - vcoreqfid
378 : vcoreqfid - vcocurrfid;
379 }
380
381 if (write_new_fid(data, fid: reqfid))
382 return 1;
383
384 if (query_current_values_with_pending_wait(data))
385 return 1;
386
387 if (data->currfid != reqfid) {
388 pr_err("ph2: mismatch, failed fid transition, curr 0x%x, req 0x%x\n",
389 data->currfid, reqfid);
390 return 1;
391 }
392
393 if (savevid != data->currvid) {
394 pr_err("ph2: vid changed, save 0x%x, curr 0x%x\n",
395 savevid, data->currvid);
396 return 1;
397 }
398
399 pr_debug("ph2 complete, currfid 0x%x, currvid 0x%x\n",
400 data->currfid, data->currvid);
401
402 return 0;
403}
404
405/* Phase 3 - core voltage transition flow ... jump to the final vid. */
406static int core_voltage_post_transition(struct powernow_k8_data *data,
407 u32 reqvid)
408{
409 u32 savefid = data->currfid;
410 u32 savereqvid = reqvid;
411
412 pr_debug("ph3 (cpu%d): starting, currfid 0x%x, currvid 0x%x\n",
413 smp_processor_id(),
414 data->currfid, data->currvid);
415
416 if (reqvid != data->currvid) {
417 if (write_new_vid(data, vid: reqvid))
418 return 1;
419
420 if (savefid != data->currfid) {
421 pr_err("ph3: bad fid change, save 0x%x, curr 0x%x\n",
422 savefid, data->currfid);
423 return 1;
424 }
425
426 if (data->currvid != reqvid) {
427 pr_err("ph3: failed vid transition\n, req 0x%x, curr 0x%x",
428 reqvid, data->currvid);
429 return 1;
430 }
431 }
432
433 if (query_current_values_with_pending_wait(data))
434 return 1;
435
436 if (savereqvid != data->currvid) {
437 pr_debug("ph3 failed, currvid 0x%x\n", data->currvid);
438 return 1;
439 }
440
441 if (savefid != data->currfid) {
442 pr_debug("ph3 failed, currfid changed 0x%x\n",
443 data->currfid);
444 return 1;
445 }
446
447 pr_debug("ph3 complete, currfid 0x%x, currvid 0x%x\n",
448 data->currfid, data->currvid);
449
450 return 0;
451}
452
453static const struct x86_cpu_id powernow_k8_ids[] = {
454 /* IO based frequency switching */
455 X86_MATCH_VENDOR_FAM(AMD, 0xf, NULL),
456 {}
457};
458MODULE_DEVICE_TABLE(x86cpu, powernow_k8_ids);
459
460static void check_supported_cpu(void *_rc)
461{
462 u32 eax, ebx, ecx, edx;
463 int *rc = _rc;
464
465 *rc = -ENODEV;
466
467 eax = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
468
469 if ((eax & CPUID_XFAM) == CPUID_XFAM_K8) {
470 if (((eax & CPUID_USE_XFAM_XMOD) != CPUID_USE_XFAM_XMOD) ||
471 ((eax & CPUID_XMOD) > CPUID_XMOD_REV_MASK)) {
472 pr_info("Processor cpuid %x not supported\n", eax);
473 return;
474 }
475
476 eax = cpuid_eax(CPUID_GET_MAX_CAPABILITIES);
477 if (eax < CPUID_FREQ_VOLT_CAPABILITIES) {
478 pr_info("No frequency change capabilities detected\n");
479 return;
480 }
481
482 cpuid(CPUID_FREQ_VOLT_CAPABILITIES, eax: &eax, ebx: &ebx, ecx: &ecx, edx: &edx);
483 if ((edx & P_STATE_TRANSITION_CAPABLE)
484 != P_STATE_TRANSITION_CAPABLE) {
485 pr_info("Power state transitions not supported\n");
486 return;
487 }
488 *rc = 0;
489 }
490}
491
492static int check_pst_table(struct powernow_k8_data *data, struct pst_s *pst,
493 u8 maxvid)
494{
495 unsigned int j;
496 u8 lastfid = 0xff;
497
498 for (j = 0; j < data->numps; j++) {
499 if (pst[j].vid > LEAST_VID) {
500 pr_err(FW_BUG "vid %d invalid : 0x%x\n", j,
501 pst[j].vid);
502 return -EINVAL;
503 }
504 if (pst[j].vid < data->rvo) {
505 /* vid + rvo >= 0 */
506 pr_err(FW_BUG "0 vid exceeded with pstate %d\n", j);
507 return -ENODEV;
508 }
509 if (pst[j].vid < maxvid + data->rvo) {
510 /* vid + rvo >= maxvid */
511 pr_err(FW_BUG "maxvid exceeded with pstate %d\n", j);
512 return -ENODEV;
513 }
514 if (pst[j].fid > MAX_FID) {
515 pr_err(FW_BUG "maxfid exceeded with pstate %d\n", j);
516 return -ENODEV;
517 }
518 if (j && (pst[j].fid < HI_FID_TABLE_BOTTOM)) {
519 /* Only first fid is allowed to be in "low" range */
520 pr_err(FW_BUG "two low fids - %d : 0x%x\n", j,
521 pst[j].fid);
522 return -EINVAL;
523 }
524 if (pst[j].fid < lastfid)
525 lastfid = pst[j].fid;
526 }
527 if (lastfid & 1) {
528 pr_err(FW_BUG "lastfid invalid\n");
529 return -EINVAL;
530 }
531 if (lastfid > LO_FID_TABLE_TOP)
532 pr_info(FW_BUG "first fid not from lo freq table\n");
533
534 return 0;
535}
536
537static void invalidate_entry(struct cpufreq_frequency_table *powernow_table,
538 unsigned int entry)
539{
540 powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID;
541}
542
543static void print_basics(struct powernow_k8_data *data)
544{
545 int j;
546 for (j = 0; j < data->numps; j++) {
547 if (data->powernow_table[j].frequency !=
548 CPUFREQ_ENTRY_INVALID) {
549 pr_info("fid 0x%x (%d MHz), vid 0x%x\n",
550 data->powernow_table[j].driver_data & 0xff,
551 data->powernow_table[j].frequency/1000,
552 data->powernow_table[j].driver_data >> 8);
553 }
554 }
555 if (data->batps)
556 pr_info("Only %d pstates on battery\n", data->batps);
557}
558
559static int fill_powernow_table(struct powernow_k8_data *data,
560 struct pst_s *pst, u8 maxvid)
561{
562 struct cpufreq_frequency_table *powernow_table;
563 unsigned int j;
564
565 if (data->batps) {
566 /* use ACPI support to get full speed on mains power */
567 pr_warn("Only %d pstates usable (use ACPI driver for full range\n",
568 data->batps);
569 data->numps = data->batps;
570 }
571
572 for (j = 1; j < data->numps; j++) {
573 if (pst[j-1].fid >= pst[j].fid) {
574 pr_err("PST out of sequence\n");
575 return -EINVAL;
576 }
577 }
578
579 if (data->numps < 2) {
580 pr_err("no p states to transition\n");
581 return -ENODEV;
582 }
583
584 if (check_pst_table(data, pst, maxvid))
585 return -EINVAL;
586
587 powernow_table = kzalloc(size: (sizeof(*powernow_table)
588 * (data->numps + 1)), GFP_KERNEL);
589 if (!powernow_table)
590 return -ENOMEM;
591
592 for (j = 0; j < data->numps; j++) {
593 int freq;
594 powernow_table[j].driver_data = pst[j].fid; /* lower 8 bits */
595 powernow_table[j].driver_data |= (pst[j].vid << 8); /* upper 8 bits */
596 freq = find_khz_freq_from_fid(fid: pst[j].fid);
597 powernow_table[j].frequency = freq;
598 }
599 powernow_table[data->numps].frequency = CPUFREQ_TABLE_END;
600 powernow_table[data->numps].driver_data = 0;
601
602 if (query_current_values_with_pending_wait(data)) {
603 kfree(objp: powernow_table);
604 return -EIO;
605 }
606
607 pr_debug("cfid 0x%x, cvid 0x%x\n", data->currfid, data->currvid);
608 data->powernow_table = powernow_table;
609 if (cpumask_first(topology_core_cpumask(data->cpu)) == data->cpu)
610 print_basics(data);
611
612 for (j = 0; j < data->numps; j++)
613 if ((pst[j].fid == data->currfid) &&
614 (pst[j].vid == data->currvid))
615 return 0;
616
617 pr_debug("currfid/vid do not match PST, ignoring\n");
618 return 0;
619}
620
621/* Find and validate the PSB/PST table in BIOS. */
622static int find_psb_table(struct powernow_k8_data *data)
623{
624 struct psb_s *psb;
625 unsigned int i;
626 u32 mvs;
627 u8 maxvid;
628 u32 cpst = 0;
629 u32 thiscpuid;
630
631 for (i = 0xc0000; i < 0xffff0; i += 0x10) {
632 /* Scan BIOS looking for the signature. */
633 /* It can not be at ffff0 - it is too big. */
634
635 psb = phys_to_virt(address: i);
636 if (memcmp(p: psb, PSB_ID_STRING, PSB_ID_STRING_LEN) != 0)
637 continue;
638
639 pr_debug("found PSB header at 0x%p\n", psb);
640
641 pr_debug("table vers: 0x%x\n", psb->tableversion);
642 if (psb->tableversion != PSB_VERSION_1_4) {
643 pr_err(FW_BUG "PSB table is not v1.4\n");
644 return -ENODEV;
645 }
646
647 pr_debug("flags: 0x%x\n", psb->flags1);
648 if (psb->flags1) {
649 pr_err(FW_BUG "unknown flags\n");
650 return -ENODEV;
651 }
652
653 data->vstable = psb->vstable;
654 pr_debug("voltage stabilization time: %d(*20us)\n",
655 data->vstable);
656
657 pr_debug("flags2: 0x%x\n", psb->flags2);
658 data->rvo = psb->flags2 & 3;
659 data->irt = ((psb->flags2) >> 2) & 3;
660 mvs = ((psb->flags2) >> 4) & 3;
661 data->vidmvs = 1 << mvs;
662 data->batps = ((psb->flags2) >> 6) & 3;
663
664 pr_debug("ramp voltage offset: %d\n", data->rvo);
665 pr_debug("isochronous relief time: %d\n", data->irt);
666 pr_debug("maximum voltage step: %d - 0x%x\n", mvs, data->vidmvs);
667
668 pr_debug("numpst: 0x%x\n", psb->num_tables);
669 cpst = psb->num_tables;
670 if ((psb->cpuid == 0x00000fc0) ||
671 (psb->cpuid == 0x00000fe0)) {
672 thiscpuid = cpuid_eax(CPUID_PROCESSOR_SIGNATURE);
673 if ((thiscpuid == 0x00000fc0) ||
674 (thiscpuid == 0x00000fe0))
675 cpst = 1;
676 }
677 if (cpst != 1) {
678 pr_err(FW_BUG "numpst must be 1\n");
679 return -ENODEV;
680 }
681
682 data->plllock = psb->plllocktime;
683 pr_debug("plllocktime: 0x%x (units 1us)\n", psb->plllocktime);
684 pr_debug("maxfid: 0x%x\n", psb->maxfid);
685 pr_debug("maxvid: 0x%x\n", psb->maxvid);
686 maxvid = psb->maxvid;
687
688 data->numps = psb->numps;
689 pr_debug("numpstates: 0x%x\n", data->numps);
690 return fill_powernow_table(data,
691 pst: (struct pst_s *)(psb+1), maxvid);
692 }
693 /*
694 * If you see this message, complain to BIOS manufacturer. If
695 * he tells you "we do not support Linux" or some similar
696 * nonsense, remember that Windows 2000 uses the same legacy
697 * mechanism that the old Linux PSB driver uses. Tell them it
698 * is broken with Windows 2000.
699 *
700 * The reference to the AMD documentation is chapter 9 in the
701 * BIOS and Kernel Developer's Guide, which is available on
702 * www.amd.com
703 */
704 pr_err(FW_BUG "No PSB or ACPI _PSS objects\n");
705 pr_err("Make sure that your BIOS is up to date and Cool'N'Quiet support is enabled in BIOS setup\n");
706 return -ENODEV;
707}
708
709static void powernow_k8_acpi_pst_values(struct powernow_k8_data *data,
710 unsigned int index)
711{
712 u64 control;
713
714 if (!data->acpi_data.state_count)
715 return;
716
717 control = data->acpi_data.states[index].control;
718 data->irt = (control >> IRT_SHIFT) & IRT_MASK;
719 data->rvo = (control >> RVO_SHIFT) & RVO_MASK;
720 data->exttype = (control >> EXT_TYPE_SHIFT) & EXT_TYPE_MASK;
721 data->plllock = (control >> PLL_L_SHIFT) & PLL_L_MASK;
722 data->vidmvs = 1 << ((control >> MVS_SHIFT) & MVS_MASK);
723 data->vstable = (control >> VST_SHIFT) & VST_MASK;
724}
725
726static int powernow_k8_cpu_init_acpi(struct powernow_k8_data *data)
727{
728 struct cpufreq_frequency_table *powernow_table;
729 int ret_val = -ENODEV;
730 u64 control, status;
731
732 if (acpi_processor_register_performance(performance: &data->acpi_data, cpu: data->cpu)) {
733 pr_debug("register performance failed: bad ACPI data\n");
734 return -EIO;
735 }
736
737 /* verify the data contained in the ACPI structures */
738 if (data->acpi_data.state_count <= 1) {
739 pr_debug("No ACPI P-States\n");
740 goto err_out;
741 }
742
743 control = data->acpi_data.control_register.space_id;
744 status = data->acpi_data.status_register.space_id;
745
746 if ((control != ACPI_ADR_SPACE_FIXED_HARDWARE) ||
747 (status != ACPI_ADR_SPACE_FIXED_HARDWARE)) {
748 pr_debug("Invalid control/status registers (%llx - %llx)\n",
749 control, status);
750 goto err_out;
751 }
752
753 /* fill in data->powernow_table */
754 powernow_table = kzalloc(size: (sizeof(*powernow_table)
755 * (data->acpi_data.state_count + 1)), GFP_KERNEL);
756 if (!powernow_table)
757 goto err_out;
758
759 /* fill in data */
760 data->numps = data->acpi_data.state_count;
761 powernow_k8_acpi_pst_values(data, index: 0);
762
763 ret_val = fill_powernow_table_fidvid(data, powernow_table);
764 if (ret_val)
765 goto err_out_mem;
766
767 powernow_table[data->acpi_data.state_count].frequency =
768 CPUFREQ_TABLE_END;
769 data->powernow_table = powernow_table;
770
771 if (cpumask_first(topology_core_cpumask(data->cpu)) == data->cpu)
772 print_basics(data);
773
774 /* notify BIOS that we exist */
775 acpi_processor_notify_smm(THIS_MODULE);
776
777 if (!zalloc_cpumask_var(mask: &data->acpi_data.shared_cpu_map, GFP_KERNEL)) {
778 pr_err("unable to alloc powernow_k8_data cpumask\n");
779 ret_val = -ENOMEM;
780 goto err_out_mem;
781 }
782
783 return 0;
784
785err_out_mem:
786 kfree(objp: powernow_table);
787
788err_out:
789 acpi_processor_unregister_performance(cpu: data->cpu);
790
791 /* data->acpi_data.state_count informs us at ->exit()
792 * whether ACPI was used */
793 data->acpi_data.state_count = 0;
794
795 return ret_val;
796}
797
798static int fill_powernow_table_fidvid(struct powernow_k8_data *data,
799 struct cpufreq_frequency_table *powernow_table)
800{
801 int i;
802
803 for (i = 0; i < data->acpi_data.state_count; i++) {
804 u32 fid;
805 u32 vid;
806 u32 freq, index;
807 u64 status, control;
808
809 if (data->exttype) {
810 status = data->acpi_data.states[i].status;
811 fid = status & EXT_FID_MASK;
812 vid = (status >> VID_SHIFT) & EXT_VID_MASK;
813 } else {
814 control = data->acpi_data.states[i].control;
815 fid = control & FID_MASK;
816 vid = (control >> VID_SHIFT) & VID_MASK;
817 }
818
819 pr_debug(" %d : fid 0x%x, vid 0x%x\n", i, fid, vid);
820
821 index = fid | (vid<<8);
822 powernow_table[i].driver_data = index;
823
824 freq = find_khz_freq_from_fid(fid);
825 powernow_table[i].frequency = freq;
826
827 /* verify frequency is OK */
828 if ((freq > (MAX_FREQ * 1000)) || (freq < (MIN_FREQ * 1000))) {
829 pr_debug("invalid freq %u kHz, ignoring\n", freq);
830 invalidate_entry(powernow_table, entry: i);
831 continue;
832 }
833
834 /* verify voltage is OK -
835 * BIOSs are using "off" to indicate invalid */
836 if (vid == VID_OFF) {
837 pr_debug("invalid vid %u, ignoring\n", vid);
838 invalidate_entry(powernow_table, entry: i);
839 continue;
840 }
841
842 if (freq != (data->acpi_data.states[i].core_frequency * 1000)) {
843 pr_info("invalid freq entries %u kHz vs. %u kHz\n",
844 freq, (unsigned int)
845 (data->acpi_data.states[i].core_frequency
846 * 1000));
847 invalidate_entry(powernow_table, entry: i);
848 continue;
849 }
850 }
851 return 0;
852}
853
854static void powernow_k8_cpu_exit_acpi(struct powernow_k8_data *data)
855{
856 if (data->acpi_data.state_count)
857 acpi_processor_unregister_performance(cpu: data->cpu);
858 free_cpumask_var(mask: data->acpi_data.shared_cpu_map);
859}
860
861static int get_transition_latency(struct powernow_k8_data *data)
862{
863 int max_latency = 0;
864 int i;
865 for (i = 0; i < data->acpi_data.state_count; i++) {
866 int cur_latency = data->acpi_data.states[i].transition_latency
867 + data->acpi_data.states[i].bus_master_latency;
868 if (cur_latency > max_latency)
869 max_latency = cur_latency;
870 }
871 if (max_latency == 0) {
872 pr_err(FW_WARN "Invalid zero transition latency\n");
873 max_latency = 1;
874 }
875 /* value in usecs, needs to be in nanoseconds */
876 return 1000 * max_latency;
877}
878
879/* Take a frequency, and issue the fid/vid transition command */
880static int transition_frequency_fidvid(struct powernow_k8_data *data,
881 unsigned int index,
882 struct cpufreq_policy *policy)
883{
884 u32 fid = 0;
885 u32 vid = 0;
886 int res;
887 struct cpufreq_freqs freqs;
888
889 pr_debug("cpu %d transition to index %u\n", smp_processor_id(), index);
890
891 /* fid/vid correctness check for k8 */
892 /* fid are the lower 8 bits of the index we stored into
893 * the cpufreq frequency table in find_psb_table, vid
894 * are the upper 8 bits.
895 */
896 fid = data->powernow_table[index].driver_data & 0xFF;
897 vid = (data->powernow_table[index].driver_data & 0xFF00) >> 8;
898
899 pr_debug("table matched fid 0x%x, giving vid 0x%x\n", fid, vid);
900
901 if (query_current_values_with_pending_wait(data))
902 return 1;
903
904 if ((data->currvid == vid) && (data->currfid == fid)) {
905 pr_debug("target matches current values (fid 0x%x, vid 0x%x)\n",
906 fid, vid);
907 return 0;
908 }
909
910 pr_debug("cpu %d, changing to fid 0x%x, vid 0x%x\n",
911 smp_processor_id(), fid, vid);
912 freqs.old = find_khz_freq_from_fid(fid: data->currfid);
913 freqs.new = find_khz_freq_from_fid(fid);
914
915 cpufreq_freq_transition_begin(policy, freqs: &freqs);
916 res = transition_fid_vid(data, reqfid: fid, reqvid: vid);
917 cpufreq_freq_transition_end(policy, freqs: &freqs, transition_failed: res);
918
919 return res;
920}
921
922struct powernowk8_target_arg {
923 struct cpufreq_policy *pol;
924 unsigned newstate;
925};
926
927static long powernowk8_target_fn(void *arg)
928{
929 struct powernowk8_target_arg *pta = arg;
930 struct cpufreq_policy *pol = pta->pol;
931 unsigned newstate = pta->newstate;
932 struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
933 u32 checkfid;
934 u32 checkvid;
935 int ret;
936
937 if (!data)
938 return -EINVAL;
939
940 checkfid = data->currfid;
941 checkvid = data->currvid;
942
943 if (pending_bit_stuck()) {
944 pr_err("failing targ, change pending bit set\n");
945 return -EIO;
946 }
947
948 pr_debug("targ: cpu %d, %d kHz, min %d, max %d\n",
949 pol->cpu, data->powernow_table[newstate].frequency, pol->min,
950 pol->max);
951
952 if (query_current_values_with_pending_wait(data))
953 return -EIO;
954
955 pr_debug("targ: curr fid 0x%x, vid 0x%x\n",
956 data->currfid, data->currvid);
957
958 if ((checkvid != data->currvid) ||
959 (checkfid != data->currfid)) {
960 pr_info("error - out of sync, fix 0x%x 0x%x, vid 0x%x 0x%x\n",
961 checkfid, data->currfid,
962 checkvid, data->currvid);
963 }
964
965 mutex_lock(&fidvid_mutex);
966
967 powernow_k8_acpi_pst_values(data, index: newstate);
968
969 ret = transition_frequency_fidvid(data, index: newstate, policy: pol);
970
971 if (ret) {
972 pr_err("transition frequency failed\n");
973 mutex_unlock(lock: &fidvid_mutex);
974 return 1;
975 }
976 mutex_unlock(lock: &fidvid_mutex);
977
978 pol->cur = find_khz_freq_from_fid(fid: data->currfid);
979
980 return 0;
981}
982
983/* Driver entry point to switch to the target frequency */
984static int powernowk8_target(struct cpufreq_policy *pol, unsigned index)
985{
986 struct powernowk8_target_arg pta = { .pol = pol, .newstate = index };
987
988 return work_on_cpu(pol->cpu, powernowk8_target_fn, &pta);
989}
990
991struct init_on_cpu {
992 struct powernow_k8_data *data;
993 int rc;
994};
995
996static void powernowk8_cpu_init_on_cpu(void *_init_on_cpu)
997{
998 struct init_on_cpu *init_on_cpu = _init_on_cpu;
999
1000 if (pending_bit_stuck()) {
1001 pr_err("failing init, change pending bit set\n");
1002 init_on_cpu->rc = -ENODEV;
1003 return;
1004 }
1005
1006 if (query_current_values_with_pending_wait(data: init_on_cpu->data)) {
1007 init_on_cpu->rc = -ENODEV;
1008 return;
1009 }
1010
1011 fidvid_msr_init();
1012
1013 init_on_cpu->rc = 0;
1014}
1015
1016#define MISSING_PSS_MSG \
1017 FW_BUG "No compatible ACPI _PSS objects found.\n" \
1018 FW_BUG "First, make sure Cool'N'Quiet is enabled in the BIOS.\n" \
1019 FW_BUG "If that doesn't help, try upgrading your BIOS.\n"
1020
1021/* per CPU init entry point to the driver */
1022static int powernowk8_cpu_init(struct cpufreq_policy *pol)
1023{
1024 struct powernow_k8_data *data;
1025 struct init_on_cpu init_on_cpu;
1026 int rc, cpu;
1027
1028 smp_call_function_single(cpuid: pol->cpu, func: check_supported_cpu, info: &rc, wait: 1);
1029 if (rc)
1030 return -ENODEV;
1031
1032 data = kzalloc(size: sizeof(*data), GFP_KERNEL);
1033 if (!data)
1034 return -ENOMEM;
1035
1036 data->cpu = pol->cpu;
1037
1038 if (powernow_k8_cpu_init_acpi(data)) {
1039 /*
1040 * Use the PSB BIOS structure. This is only available on
1041 * an UP version, and is deprecated by AMD.
1042 */
1043 if (num_online_cpus() != 1) {
1044 pr_err_once(MISSING_PSS_MSG);
1045 goto err_out;
1046 }
1047 if (pol->cpu != 0) {
1048 pr_err(FW_BUG "No ACPI _PSS objects for CPU other than CPU0. Complain to your BIOS vendor.\n");
1049 goto err_out;
1050 }
1051 rc = find_psb_table(data);
1052 if (rc)
1053 goto err_out;
1054
1055 /* Take a crude guess here.
1056 * That guess was in microseconds, so multiply with 1000 */
1057 pol->cpuinfo.transition_latency = (
1058 ((data->rvo + 8) * data->vstable * VST_UNITS_20US) +
1059 ((1 << data->irt) * 30)) * 1000;
1060 } else /* ACPI _PSS objects available */
1061 pol->cpuinfo.transition_latency = get_transition_latency(data);
1062
1063 /* only run on specific CPU from here on */
1064 init_on_cpu.data = data;
1065 smp_call_function_single(cpuid: data->cpu, func: powernowk8_cpu_init_on_cpu,
1066 info: &init_on_cpu, wait: 1);
1067 rc = init_on_cpu.rc;
1068 if (rc != 0)
1069 goto err_out_exit_acpi;
1070
1071 cpumask_copy(dstp: pol->cpus, topology_core_cpumask(pol->cpu));
1072 data->available_cores = pol->cpus;
1073 pol->freq_table = data->powernow_table;
1074
1075 pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n",
1076 data->currfid, data->currvid);
1077
1078 /* Point all the CPUs in this policy to the same data */
1079 for_each_cpu(cpu, pol->cpus)
1080 per_cpu(powernow_data, cpu) = data;
1081
1082 return 0;
1083
1084err_out_exit_acpi:
1085 powernow_k8_cpu_exit_acpi(data);
1086
1087err_out:
1088 kfree(objp: data);
1089 return -ENODEV;
1090}
1091
1092static int powernowk8_cpu_exit(struct cpufreq_policy *pol)
1093{
1094 struct powernow_k8_data *data = per_cpu(powernow_data, pol->cpu);
1095 int cpu;
1096
1097 if (!data)
1098 return -EINVAL;
1099
1100 powernow_k8_cpu_exit_acpi(data);
1101
1102 kfree(objp: data->powernow_table);
1103 kfree(objp: data);
1104 /* pol->cpus will be empty here, use related_cpus instead. */
1105 for_each_cpu(cpu, pol->related_cpus)
1106 per_cpu(powernow_data, cpu) = NULL;
1107
1108 return 0;
1109}
1110
1111static void query_values_on_cpu(void *_err)
1112{
1113 int *err = _err;
1114 struct powernow_k8_data *data = __this_cpu_read(powernow_data);
1115
1116 *err = query_current_values_with_pending_wait(data);
1117}
1118
1119static unsigned int powernowk8_get(unsigned int cpu)
1120{
1121 struct powernow_k8_data *data = per_cpu(powernow_data, cpu);
1122 unsigned int khz = 0;
1123 int err;
1124
1125 if (!data)
1126 return 0;
1127
1128 smp_call_function_single(cpuid: cpu, func: query_values_on_cpu, info: &err, wait: true);
1129 if (err)
1130 goto out;
1131
1132 khz = find_khz_freq_from_fid(fid: data->currfid);
1133
1134
1135out:
1136 return khz;
1137}
1138
1139static struct cpufreq_driver cpufreq_amd64_driver = {
1140 .flags = CPUFREQ_ASYNC_NOTIFICATION,
1141 .verify = cpufreq_generic_frequency_table_verify,
1142 .target_index = powernowk8_target,
1143 .bios_limit = acpi_processor_get_bios_limit,
1144 .init = powernowk8_cpu_init,
1145 .exit = powernowk8_cpu_exit,
1146 .get = powernowk8_get,
1147 .name = "powernow-k8",
1148 .attr = cpufreq_generic_attr,
1149};
1150
1151static void __request_acpi_cpufreq(void)
1152{
1153 const char drv[] = "acpi-cpufreq";
1154 const char *cur_drv;
1155
1156 cur_drv = cpufreq_get_current_driver();
1157 if (!cur_drv)
1158 goto request;
1159
1160 if (strncmp(cur_drv, drv, min_t(size_t, strlen(cur_drv), strlen(drv))))
1161 pr_warn("WTF driver: %s\n", cur_drv);
1162
1163 return;
1164
1165 request:
1166 pr_warn("This CPU is not supported anymore, using acpi-cpufreq instead.\n");
1167 request_module(drv);
1168}
1169
1170/* driver entry point for init */
1171static int powernowk8_init(void)
1172{
1173 unsigned int i, supported_cpus = 0;
1174 int ret;
1175
1176 if (!x86_match_cpu(match: powernow_k8_ids))
1177 return -ENODEV;
1178
1179 if (boot_cpu_has(X86_FEATURE_HW_PSTATE)) {
1180 __request_acpi_cpufreq();
1181 return -ENODEV;
1182 }
1183
1184 cpus_read_lock();
1185 for_each_online_cpu(i) {
1186 smp_call_function_single(cpuid: i, func: check_supported_cpu, info: &ret, wait: 1);
1187 if (!ret)
1188 supported_cpus++;
1189 }
1190
1191 if (supported_cpus != num_online_cpus()) {
1192 cpus_read_unlock();
1193 return -ENODEV;
1194 }
1195 cpus_read_unlock();
1196
1197 ret = cpufreq_register_driver(driver_data: &cpufreq_amd64_driver);
1198 if (ret)
1199 return ret;
1200
1201 pr_info("Found %d %s (%d cpu cores) (" VERSION ")\n",
1202 num_online_nodes(), boot_cpu_data.x86_model_id, supported_cpus);
1203
1204 return ret;
1205}
1206
1207/* driver entry point for term */
1208static void __exit powernowk8_exit(void)
1209{
1210 pr_debug("exit\n");
1211
1212 cpufreq_unregister_driver(driver_data: &cpufreq_amd64_driver);
1213}
1214
1215MODULE_AUTHOR("Paul Devriendt <paul.devriendt@amd.com>");
1216MODULE_AUTHOR("Mark Langsdorf <mark.langsdorf@amd.com>");
1217MODULE_DESCRIPTION("AMD Athlon 64 and Opteron processor frequency driver.");
1218MODULE_LICENSE("GPL");
1219
1220late_initcall(powernowk8_init);
1221module_exit(powernowk8_exit);
1222

source code of linux/drivers/cpufreq/powernow-k8.c