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() */
37 #include <linux/delay.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"
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
;
64 static inline const struct cpumask
*cpu_core_mask(int cpu
)
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
,
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
94 static u32
convert_fid_to_vco_fid(u32 fid
)
96 if (fid
< HI_FID_TABLE_BOTTOM
)
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)
110 if (cpu_family
== CPU_HW_PSTATE
)
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
)
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
;
142 pr_debug("detected change pending stuck\n");
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
;
154 /* the isochronous relief time */
155 static void count_off_irt(struct powernow_k8_data
*data
)
157 udelay((1 << data
->irt
) * 10);
161 /* the voltage stabilization time */
162 static void count_off_vst(struct powernow_k8_data
*data
)
164 udelay(data
->vstable
* VST_UNITS_20US
);
168 /* need to init the control msr to a safe value (for each cpu) */
169 static void fidvid_msr_init(void)
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
)
187 u32 savevid
= data
->currvid
;
190 if ((fid
& INVALID_FID_MASK
) || (data
->currvid
& INVALID_VID_MASK
)) {
191 printk(KERN_ERR PFX
"internal error - overflow on fid write\n");
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
);
203 wrmsr(MSR_FIDVID_CTL
, lo
, data
->plllock
* PLL_LOCK_CONVERSION
);
206 "Hardware error - pending bit very stuck - "
207 "no further pstate changes possible\n");
210 } while (query_current_values_with_pending_wait(data
));
214 if (savevid
!= data
->currvid
) {
216 "vid change on fid trans, old 0x%x, new 0x%x\n",
217 savevid
, data
->currvid
);
221 if (fid
!= data
->currfid
) {
223 "fid trans failed, fid 0x%x, curr 0x%x\n", fid
,
231 /* Write a new vid to the hardware */
232 static int write_new_vid(struct powernow_k8_data
*data
, u32 vid
)
235 u32 savefid
= data
->currfid
;
238 if ((data
->currfid
& INVALID_FID_MASK
) || (vid
& INVALID_VID_MASK
)) {
239 printk(KERN_ERR PFX
"internal error - overflow on vid write\n");
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
);
251 wrmsr(MSR_FIDVID_CTL
, lo
, STOP_GRANT_5NS
);
253 printk(KERN_ERR PFX
"internal error - pending bit "
254 "very stuck - no further pstate "
255 "changes possible\n");
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 "
263 savefid
, data
->currfid
);
267 if (vid
!= data
->currvid
) {
268 printk(KERN_ERR PFX
"vid trans failed, vid 0x%x, "
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
))
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
;
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
))
311 if (core_frequency_transition(data
, reqfid
))
314 if (core_voltage_post_transition(data
, reqvid
))
317 if (query_current_values_with_pending_wait(data
))
320 if ((reqfid
!= data
->currfid
) || (reqvid
!= data
->currvid
)) {
321 printk(KERN_ERR PFX
"failed (cpu%d): req 0x%x 0x%x, "
324 reqfid
, reqvid
, data
->currfid
, data
->currvid
);
328 pr_debug("transitioned (cpu%d): new fid 0x%x, vid 0x%x\n",
329 smp_processor_id(), data
->currfid
, data
->currvid
);
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",
345 data
->currfid
, data
->currvid
, reqvid
, data
->rvo
);
347 if ((savefid
< LO_FID_TABLE_TOP
) && (reqfid
< LO_FID_TABLE_TOP
))
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 */
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
))
363 while ((rvosteps
> 0) &&
364 ((rvomult
* data
->rvo
+ data
->currvid
) > reqvid
)) {
365 if (data
->currvid
== maxvid
) {
368 pr_debug("ph1: changing vid for rvo, req 0x%x\n",
370 if (decrease_vid_code_by_step(data
, data
->currvid
-1, 1))
376 if (query_current_values_with_pending_wait(data
))
379 if (savefid
!= data
->currfid
) {
380 printk(KERN_ERR PFX
"ph1 err, currfid changed 0x%x\n",
385 pr_debug("ph1 complete, currfid 0x%x, currvid 0x%x\n",
386 data
->currfid
, data
->currvid
);
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",
403 pr_debug("ph2 (cpu%d): starting, currfid 0x%x, currvid 0x%x, "
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
))
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
))
427 2 + convert_fid_to_vco_fid(data
->currfid
)))
431 if (write_new_fid(data
, data
->currfid
- fid_interval
))
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
))
443 if (query_current_values_with_pending_wait(data
))
446 if (data
->currfid
!= reqfid
) {
448 "ph2: mismatch, failed fid transition, "
449 "curr 0x%x, req 0x%x\n",
450 data
->currfid
, reqfid
);
454 if (savevid
!= data
->currvid
) {
455 printk(KERN_ERR PFX
"ph2: vid changed, save 0x%x, curr 0x%x\n",
456 savevid
, data
->currvid
);
460 pr_debug("ph2 complete, currfid 0x%x, currvid 0x%x\n",
461 data
->currfid
, data
->currvid
);
466 /* Phase 3 - core voltage transition flow ... jump to the final vid. */
467 static int core_voltage_post_transition(struct powernow_k8_data
*data
,
470 u32 savefid
= data
->currfid
;
471 u32 savereqvid
= reqvid
;
473 pr_debug("ph3 (cpu%d): starting, currfid 0x%x, currvid 0x%x\n",
475 data
->currfid
, data
->currvid
);
477 if (reqvid
!= data
->currvid
) {
478 if (write_new_vid(data
, reqvid
))
481 if (savefid
!= data
->currfid
) {
483 "ph3: bad fid change, save 0x%x, curr 0x%x\n",
484 savefid
, data
->currfid
);
488 if (data
->currvid
!= reqvid
) {
490 "ph3: failed vid transition\n, "
491 "req 0x%x, curr 0x%x",
492 reqvid
, data
->currvid
);
497 if (query_current_values_with_pending_wait(data
))
500 if (savereqvid
!= data
->currvid
) {
501 pr_debug("ph3 failed, currvid 0x%x\n", data
->currvid
);
505 if (savefid
!= data
->currfid
) {
506 pr_debug("ph3 failed, currfid changed 0x%x\n",
511 pr_debug("ph3 complete, currfid 0x%x, currvid 0x%x\n",
512 data
->currfid
, data
->currvid
);
517 static void check_supported_cpu(void *_rc
)
519 u32 eax
, ebx
, ecx
, edx
;
524 if (__this_cpu_read(cpu_info
.x86_vendor
) != X86_VENDOR_AMD
)
527 eax
= cpuid_eax(CPUID_PROCESSOR_SIGNATURE
);
528 if (((eax
& CPUID_XFAM
) != CPUID_XFAM_K8
) &&
529 ((eax
& CPUID_XFAM
) < CPUID_XFAM_10H
))
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
)) {
536 "Processor cpuid %x not supported\n", eax
);
540 eax
= cpuid_eax(CPUID_GET_MAX_CAPABILITIES
);
541 if (eax
< CPUID_FREQ_VOLT_CAPABILITIES
) {
543 "No frequency change capabilities detected\n");
547 cpuid(CPUID_FREQ_VOLT_CAPABILITIES
, &eax
, &ebx
, &ecx
, &edx
);
548 if ((edx
& P_STATE_TRANSITION_CAPABLE
)
549 != P_STATE_TRANSITION_CAPABLE
) {
551 "Power state transitions not supported\n");
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
;
565 static int check_pst_table(struct powernow_k8_data
*data
, struct pst_s
*pst
,
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",
577 if (pst
[j
].vid
< data
->rvo
) {
579 printk(KERN_ERR FW_BUG PFX
"0 vid exceeded with pstate"
583 if (pst
[j
].vid
< maxvid
+ data
->rvo
) {
584 /* vid + rvo >= maxvid */
585 printk(KERN_ERR FW_BUG PFX
"maxvid exceeded with pstate"
589 if (pst
[j
].fid
> MAX_FID
) {
590 printk(KERN_ERR FW_BUG PFX
"maxfid exceeded with pstate"
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
);
600 if (pst
[j
].fid
< lastfid
)
601 lastfid
= pst
[j
].fid
;
604 printk(KERN_ERR FW_BUG PFX
"lastfid invalid\n");
607 if (lastfid
> LO_FID_TABLE_TOP
)
608 printk(KERN_INFO FW_BUG PFX
609 "first fid not from lo freq table\n");
614 static void invalidate_entry(struct cpufreq_frequency_table
*powernow_table
,
617 powernow_table
[entry
].frequency
= CPUFREQ_ENTRY_INVALID
;
620 static void print_basics(struct powernow_k8_data
*data
)
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
) {
628 " %d : pstate %d (%d MHz)\n", j
,
629 data
->powernow_table
[j
].index
,
630 data
->powernow_table
[j
].frequency
/1000);
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);
641 printk(KERN_INFO PFX
"Only %d pstates on battery\n",
645 static u32
freq_from_fid_did(u32 fid
, u32 did
)
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
;
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
;
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");
680 if (data
->numps
< 2) {
681 printk(KERN_ERR PFX
"no p states to transition\n");
685 if (check_pst_table(data
, pst
, maxvid
))
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");
695 for (j
= 0; j
< data
->numps
; j
++) {
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
);
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
)
715 for (j
= 0; j
< data
->numps
; j
++)
716 if ((pst
[j
].fid
== data
->currfid
) &&
717 (pst
[j
].vid
== data
->currvid
))
720 pr_debug("currfid/vid do not match PST, ignoring\n");
724 /* Find and validate the PSB/PST table in BIOS. */
725 static int find_psb_table(struct powernow_k8_data
*data
)
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)
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");
750 pr_debug("flags: 0x%x\n", psb
->flags1
);
752 printk(KERN_ERR FW_BUG PFX
"unknown flags\n");
756 data
->vstable
= psb
->vstable
;
757 pr_debug("voltage stabilization time: %d(*20us)\n",
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))
781 printk(KERN_ERR FW_BUG PFX
"numpst must be 1\n");
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
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");
813 static void powernow_k8_acpi_pst_values(struct powernow_k8_data
*data
,
818 if (!data
->acpi_data
.state_count
|| (cpu_family
== CPU_HW_PSTATE
))
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
;
836 if (acpi_processor_register_performance(&data
->acpi_data
, data
->cpu
)) {
837 pr_debug("register performance failed: bad ACPI data\n");
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");
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",
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");
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
);
872 ret_val
= fill_powernow_table_fidvid(data
, powernow_table
);
876 powernow_table
[data
->acpi_data
.state_count
].frequency
=
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
)
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
)) {
889 "unable to alloc powernow_k8_data cpumask\n");
897 kfree(powernow_table
);
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;
909 static int fill_powernow_table_pstate(struct powernow_k8_data
*data
,
910 struct cpufreq_frequency_table
*powernow_table
)
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
++) {
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 "
926 invalidate_entry(powernow_table
, i
);
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
);
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);
944 powernow_table
[i
].frequency
=
945 data
->acpi_data
.states
[i
].core_frequency
* 1000;
950 static int fill_powernow_table_fidvid(struct powernow_k8_data
*data
,
951 struct cpufreq_frequency_table
*powernow_table
)
955 for (i
= 0; i
< data
->acpi_data
.state_count
; i
++) {
962 status
= data
->acpi_data
.states
[i
].status
;
963 fid
= status
& EXT_FID_MASK
;
964 vid
= (status
>> VID_SHIFT
) & EXT_VID_MASK
;
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
);
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
);
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
,
998 (data
->acpi_data
.states
[i
].core_frequency
1000 invalidate_entry(powernow_table
, i
);
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
,
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;
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 "
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
,
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
))
1065 if ((data
->currvid
== vid
) && (data
->currfid
== fid
)) {
1066 pr_debug("target matches current values (fid 0x%x, vid 0x%x)\n",
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
) {
1078 cpufreq_notify_transition(&freqs
, CPUFREQ_PRECHANGE
);
1081 res
= transition_fid_vid(data
, fid
, vid
);
1082 freqs
.new = find_khz_freq_from_fid(data
->currfid
);
1084 for_each_cpu(i
, data
->available_cores
) {
1086 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
1091 /* Take a frequency, and issue the hardware pstate transition command */
1092 static int transition_frequency_pstate(struct powernow_k8_data
*data
,
1097 struct cpufreq_freqs freqs
;
1099 pr_debug("cpu %d transition to index %u\n", smp_processor_id(), index
);
1101 /* get MSR index for hardware pstate transition */
1102 pstate
= index
& HW_PSTATE_MASK
;
1103 if (pstate
> data
->max_hw_pstate
)
1105 freqs
.old
= find_khz_freq_from_pstate(data
->powernow_table
,
1107 freqs
.new = find_khz_freq_from_pstate(data
->powernow_table
, pstate
);
1109 for_each_cpu(i
, data
->available_cores
) {
1111 cpufreq_notify_transition(&freqs
, CPUFREQ_PRECHANGE
);
1114 res
= transition_pstate(data
, pstate
);
1115 freqs
.new = find_khz_freq_from_pstate(data
->powernow_table
, pstate
);
1117 for_each_cpu(i
, data
->available_cores
) {
1119 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
1124 /* Driver entry point to switch to the target frequency */
1125 static int powernowk8_target(struct cpufreq_policy
*pol
,
1126 unsigned targfreq
, unsigned relation
)
1128 cpumask_var_t oldmask
;
1129 struct powernow_k8_data
*data
= per_cpu(powernow_data
, pol
->cpu
);
1132 unsigned int newstate
;
1138 checkfid
= data
->currfid
;
1139 checkvid
= data
->currvid
;
1141 /* only run on specific CPU from here on. */
1142 /* This is poor form: use a workqueue or smp_call_function_single */
1143 if (!alloc_cpumask_var(&oldmask
, GFP_KERNEL
))
1146 cpumask_copy(oldmask
, tsk_cpus_allowed(current
));
1147 set_cpus_allowed_ptr(current
, cpumask_of(pol
->cpu
));
1149 if (smp_processor_id() != pol
->cpu
) {
1150 printk(KERN_ERR PFX
"limiting to cpu %u failed\n", pol
->cpu
);
1154 if (pending_bit_stuck()) {
1155 printk(KERN_ERR PFX
"failing targ, change pending bit set\n");
1159 pr_debug("targ: cpu %d, %d kHz, min %d, max %d, relation %d\n",
1160 pol
->cpu
, targfreq
, pol
->min
, pol
->max
, relation
);
1162 if (query_current_values_with_pending_wait(data
))
1165 if (cpu_family
!= CPU_HW_PSTATE
) {
1166 pr_debug("targ: curr fid 0x%x, vid 0x%x\n",
1167 data
->currfid
, data
->currvid
);
1169 if ((checkvid
!= data
->currvid
) ||
1170 (checkfid
!= data
->currfid
)) {
1171 printk(KERN_INFO PFX
1172 "error - out of sync, fix 0x%x 0x%x, "
1174 checkfid
, data
->currfid
,
1175 checkvid
, data
->currvid
);
1179 if (cpufreq_frequency_table_target(pol
, data
->powernow_table
,
1180 targfreq
, relation
, &newstate
))
1183 mutex_lock(&fidvid_mutex
);
1185 powernow_k8_acpi_pst_values(data
, newstate
);
1187 if (cpu_family
== CPU_HW_PSTATE
)
1188 ret
= transition_frequency_pstate(data
, newstate
);
1190 ret
= transition_frequency_fidvid(data
, newstate
);
1192 printk(KERN_ERR PFX
"transition frequency failed\n");
1194 mutex_unlock(&fidvid_mutex
);
1197 mutex_unlock(&fidvid_mutex
);
1199 if (cpu_family
== CPU_HW_PSTATE
)
1200 pol
->cur
= find_khz_freq_from_pstate(data
->powernow_table
,
1203 pol
->cur
= find_khz_freq_from_fid(data
->currfid
);
1207 set_cpus_allowed_ptr(current
, oldmask
);
1208 free_cpumask_var(oldmask
);
1212 /* Driver entry point to verify the policy and range of frequencies */
1213 static int powernowk8_verify(struct cpufreq_policy
*pol
)
1215 struct powernow_k8_data
*data
= per_cpu(powernow_data
, pol
->cpu
);
1220 return cpufreq_frequency_table_verify(pol
, data
->powernow_table
);
1223 struct init_on_cpu
{
1224 struct powernow_k8_data
*data
;
1228 static void __cpuinit
powernowk8_cpu_init_on_cpu(void *_init_on_cpu
)
1230 struct init_on_cpu
*init_on_cpu
= _init_on_cpu
;
1232 if (pending_bit_stuck()) {
1233 printk(KERN_ERR PFX
"failing init, change pending bit set\n");
1234 init_on_cpu
->rc
= -ENODEV
;
1238 if (query_current_values_with_pending_wait(init_on_cpu
->data
)) {
1239 init_on_cpu
->rc
= -ENODEV
;
1243 if (cpu_family
== CPU_OPTERON
)
1246 init_on_cpu
->rc
= 0;
1249 /* per CPU init entry point to the driver */
1250 static int __cpuinit
powernowk8_cpu_init(struct cpufreq_policy
*pol
)
1252 static const char ACPI_PSS_BIOS_BUG_MSG
[] =
1253 KERN_ERR FW_BUG PFX
"No compatible ACPI _PSS objects found.\n"
1254 FW_BUG PFX
"Try again with latest BIOS.\n";
1255 struct powernow_k8_data
*data
;
1256 struct init_on_cpu init_on_cpu
;
1258 struct cpuinfo_x86
*c
= &cpu_data(pol
->cpu
);
1260 if (!cpu_online(pol
->cpu
))
1263 smp_call_function_single(pol
->cpu
, check_supported_cpu
, &rc
, 1);
1267 data
= kzalloc(sizeof(struct powernow_k8_data
), GFP_KERNEL
);
1269 printk(KERN_ERR PFX
"unable to alloc powernow_k8_data");
1273 data
->cpu
= pol
->cpu
;
1274 data
->currpstate
= HW_PSTATE_INVALID
;
1276 if (powernow_k8_cpu_init_acpi(data
)) {
1278 * Use the PSB BIOS structure. This is only available on
1279 * an UP version, and is deprecated by AMD.
1281 if (num_online_cpus() != 1) {
1282 printk_once(ACPI_PSS_BIOS_BUG_MSG
);
1285 if (pol
->cpu
!= 0) {
1286 printk(KERN_ERR FW_BUG PFX
"No ACPI _PSS objects for "
1287 "CPU other than CPU0. Complain to your BIOS "
1291 rc
= find_psb_table(data
);
1295 /* Take a crude guess here.
1296 * That guess was in microseconds, so multiply with 1000 */
1297 pol
->cpuinfo
.transition_latency
= (
1298 ((data
->rvo
+ 8) * data
->vstable
* VST_UNITS_20US
) +
1299 ((1 << data
->irt
) * 30)) * 1000;
1300 } else /* ACPI _PSS objects available */
1301 pol
->cpuinfo
.transition_latency
= get_transition_latency(data
);
1303 /* only run on specific CPU from here on */
1304 init_on_cpu
.data
= data
;
1305 smp_call_function_single(data
->cpu
, powernowk8_cpu_init_on_cpu
,
1307 rc
= init_on_cpu
.rc
;
1309 goto err_out_exit_acpi
;
1311 if (cpu_family
== CPU_HW_PSTATE
)
1312 cpumask_copy(pol
->cpus
, cpumask_of(pol
->cpu
));
1314 cpumask_copy(pol
->cpus
, cpu_core_mask(pol
->cpu
));
1315 data
->available_cores
= pol
->cpus
;
1317 if (cpu_family
== CPU_HW_PSTATE
)
1318 pol
->cur
= find_khz_freq_from_pstate(data
->powernow_table
,
1321 pol
->cur
= find_khz_freq_from_fid(data
->currfid
);
1322 pr_debug("policy current frequency %d kHz\n", pol
->cur
);
1324 /* min/max the cpu is capable of */
1325 if (cpufreq_frequency_table_cpuinfo(pol
, data
->powernow_table
)) {
1326 printk(KERN_ERR FW_BUG PFX
"invalid powernow_table\n");
1327 powernow_k8_cpu_exit_acpi(data
);
1328 kfree(data
->powernow_table
);
1333 /* Check for APERF/MPERF support in hardware */
1334 if (cpu_has(c
, X86_FEATURE_APERFMPERF
))
1335 cpufreq_amd64_driver
.getavg
= cpufreq_get_measured_perf
;
1337 cpufreq_frequency_table_get_attr(data
->powernow_table
, pol
->cpu
);
1339 if (cpu_family
== CPU_HW_PSTATE
)
1340 pr_debug("cpu_init done, current pstate 0x%x\n",
1343 pr_debug("cpu_init done, current fid 0x%x, vid 0x%x\n",
1344 data
->currfid
, data
->currvid
);
1346 per_cpu(powernow_data
, pol
->cpu
) = data
;
1351 powernow_k8_cpu_exit_acpi(data
);
1358 static int __devexit
powernowk8_cpu_exit(struct cpufreq_policy
*pol
)
1360 struct powernow_k8_data
*data
= per_cpu(powernow_data
, pol
->cpu
);
1365 powernow_k8_cpu_exit_acpi(data
);
1367 cpufreq_frequency_table_put_attr(pol
->cpu
);
1369 kfree(data
->powernow_table
);
1371 per_cpu(powernow_data
, pol
->cpu
) = NULL
;
1376 static void query_values_on_cpu(void *_err
)
1379 struct powernow_k8_data
*data
= __this_cpu_read(powernow_data
);
1381 *err
= query_current_values_with_pending_wait(data
);
1384 static unsigned int powernowk8_get(unsigned int cpu
)
1386 struct powernow_k8_data
*data
= per_cpu(powernow_data
, cpu
);
1387 unsigned int khz
= 0;
1393 smp_call_function_single(cpu
, query_values_on_cpu
, &err
, true);
1397 if (cpu_family
== CPU_HW_PSTATE
)
1398 khz
= find_khz_freq_from_pstate(data
->powernow_table
,
1401 khz
= find_khz_freq_from_fid(data
->currfid
);
1408 static void _cpb_toggle_msrs(bool t
)
1414 rdmsr_on_cpus(cpu_online_mask
, MSR_K7_HWCR
, msrs
);
1416 for_each_cpu(cpu
, cpu_online_mask
) {
1417 struct msr
*reg
= per_cpu_ptr(msrs
, cpu
);
1423 wrmsr_on_cpus(cpu_online_mask
, MSR_K7_HWCR
, msrs
);
1429 * Switch on/off core performance boosting.
1434 static void cpb_toggle(bool t
)
1439 if (t
&& !cpb_enabled
) {
1441 _cpb_toggle_msrs(t
);
1442 printk(KERN_INFO PFX
"Core Boosting enabled.\n");
1443 } else if (!t
&& cpb_enabled
) {
1444 cpb_enabled
= false;
1445 _cpb_toggle_msrs(t
);
1446 printk(KERN_INFO PFX
"Core Boosting disabled.\n");
1450 static ssize_t
store_cpb(struct cpufreq_policy
*policy
, const char *buf
,
1454 unsigned long val
= 0;
1456 ret
= strict_strtoul(buf
, 10, &val
);
1457 if (!ret
&& (val
== 0 || val
== 1) && cpb_capable
)
1465 static ssize_t
show_cpb(struct cpufreq_policy
*policy
, char *buf
)
1467 return sprintf(buf
, "%u\n", cpb_enabled
);
1470 #define define_one_rw(_name) \
1471 static struct freq_attr _name = \
1472 __ATTR(_name, 0644, show_##_name, store_##_name)
1476 static struct freq_attr
*powernow_k8_attr
[] = {
1477 &cpufreq_freq_attr_scaling_available_freqs
,
1482 static struct cpufreq_driver cpufreq_amd64_driver
= {
1483 .verify
= powernowk8_verify
,
1484 .target
= powernowk8_target
,
1485 .bios_limit
= acpi_processor_get_bios_limit
,
1486 .init
= powernowk8_cpu_init
,
1487 .exit
= __devexit_p(powernowk8_cpu_exit
),
1488 .get
= powernowk8_get
,
1489 .name
= "powernow-k8",
1490 .owner
= THIS_MODULE
,
1491 .attr
= powernow_k8_attr
,
1495 * Clear the boost-disable flag on the CPU_DOWN path so that this cpu
1496 * cannot block the remaining ones from boosting. On the CPU_UP path we
1497 * simply keep the boost-disable flag in sync with the current global
1500 static int cpb_notify(struct notifier_block
*nb
, unsigned long action
,
1503 unsigned cpu
= (long)hcpu
;
1507 case CPU_UP_PREPARE
:
1508 case CPU_UP_PREPARE_FROZEN
:
1511 rdmsr_on_cpu(cpu
, MSR_K7_HWCR
, &lo
, &hi
);
1513 wrmsr_on_cpu(cpu
, MSR_K7_HWCR
, lo
, hi
);
1517 case CPU_DOWN_PREPARE
:
1518 case CPU_DOWN_PREPARE_FROZEN
:
1519 rdmsr_on_cpu(cpu
, MSR_K7_HWCR
, &lo
, &hi
);
1521 wrmsr_on_cpu(cpu
, MSR_K7_HWCR
, lo
, hi
);
1531 static struct notifier_block cpb_nb
= {
1532 .notifier_call
= cpb_notify
,
1535 /* driver entry point for init */
1536 static int __cpuinit
powernowk8_init(void)
1538 unsigned int i
, supported_cpus
= 0, cpu
;
1541 for_each_online_cpu(i
) {
1543 smp_call_function_single(i
, check_supported_cpu
, &rc
, 1);
1548 if (supported_cpus
!= num_online_cpus())
1551 printk(KERN_INFO PFX
"Found %d %s (%d cpu cores) (" VERSION
")\n",
1552 num_online_nodes(), boot_cpu_data
.x86_model_id
, supported_cpus
);
1554 if (boot_cpu_has(X86_FEATURE_CPB
)) {
1558 msrs
= msrs_alloc();
1560 printk(KERN_ERR
"%s: Error allocating msrs!\n", __func__
);
1564 register_cpu_notifier(&cpb_nb
);
1566 rdmsr_on_cpus(cpu_online_mask
, MSR_K7_HWCR
, msrs
);
1568 for_each_cpu(cpu
, cpu_online_mask
) {
1569 struct msr
*reg
= per_cpu_ptr(msrs
, cpu
);
1570 cpb_enabled
|= !(!!(reg
->l
& BIT(25)));
1573 printk(KERN_INFO PFX
"Core Performance Boosting: %s.\n",
1574 (cpb_enabled
? "on" : "off"));
1577 rv
= cpufreq_register_driver(&cpufreq_amd64_driver
);
1578 if (rv
< 0 && boot_cpu_has(X86_FEATURE_CPB
)) {
1579 unregister_cpu_notifier(&cpb_nb
);
1586 /* driver entry point for term */
1587 static void __exit
powernowk8_exit(void)
1591 if (boot_cpu_has(X86_FEATURE_CPB
)) {
1595 unregister_cpu_notifier(&cpb_nb
);
1598 cpufreq_unregister_driver(&cpufreq_amd64_driver
);
1601 MODULE_AUTHOR("Paul Devriendt <paul.devriendt@amd.com> and "
1602 "Mark Langsdorf <mark.langsdorf@amd.com>");
1603 MODULE_DESCRIPTION("AMD Athlon 64 and Opteron processor frequency driver.");
1604 MODULE_LICENSE("GPL");
1606 late_initcall(powernowk8_init
);
1607 module_exit(powernowk8_exit
);