2 * AMD K7 Powernow driver.
3 * (C) 2003 Dave Jones on behalf of SuSE Labs.
4 * (C) 2003-2004 Dave Jones <davej@redhat.com>
6 * Licensed under the terms of the GNU GPL License version 2.
7 * Based upon datasheets & sample CPUs kindly provided by AMD.
10 * CPU may fail to execute a FID/VID change in presence of interrupt.
11 * - We cli/sti on stepping A0 CPUs around the FID/VID transition.
13 * CPU with half frequency multipliers may hang upon wakeup from disconnect.
14 * - We disable half multipliers if ACPI is used on A0 stepping CPUs.
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/init.h>
21 #include <linux/cpufreq.h>
22 #include <linux/slab.h>
23 #include <linux/string.h>
24 #include <linux/dmi.h>
25 #include <linux/timex.h>
28 #include <asm/timer.h> /* Needed for recalibrate_cpu_khz() */
30 #include <asm/system.h>
32 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
33 #include <linux/acpi.h>
34 #include <acpi/processor.h>
37 #include "powernow-k7.h"
39 #define PFX "powernow: "
59 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
60 union powernow_acpi_control_t
{
71 #ifdef CONFIG_CPU_FREQ_DEBUG
72 /* divide by 1000 to get VCore voltage in V. */
73 static const int mobile_vid_table
[32] = {
74 2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
75 1600, 1550, 1500, 1450, 1400, 1350, 1300, 0,
76 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
77 1075, 1050, 1025, 1000, 975, 950, 925, 0,
81 /* divide by 10 to get FID. */
82 static const int fid_codes
[32] = {
83 110, 115, 120, 125, 50, 55, 60, 65,
84 70, 75, 80, 85, 90, 95, 100, 105,
85 30, 190, 40, 200, 130, 135, 140, 210,
86 150, 225, 160, 165, 170, 180, -1, -1,
89 /* This parameter is used in order to force ACPI instead of legacy method for
90 * configuration purpose.
93 static int acpi_force
;
95 static struct cpufreq_frequency_table
*powernow_table
;
97 static unsigned int can_scale_bus
;
98 static unsigned int can_scale_vid
;
99 static unsigned int minimum_speed
= -1;
100 static unsigned int maximum_speed
;
101 static unsigned int number_scales
;
102 static unsigned int fsb
;
103 static unsigned int latency
;
106 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, \
109 static int check_fsb(unsigned int fsbspeed
)
112 unsigned int f
= fsb
/ 1000;
114 delta
= (fsbspeed
> f
) ? fsbspeed
- f
: f
- fsbspeed
;
118 static int check_powernow(void)
120 struct cpuinfo_x86
*c
= &cpu_data(0);
121 unsigned int maxei
, eax
, ebx
, ecx
, edx
;
123 if ((c
->x86_vendor
!= X86_VENDOR_AMD
) || (c
->x86
!= 6)) {
125 printk(KERN_INFO PFX
"This module only works with "
131 /* Get maximum capabilities */
132 maxei
= cpuid_eax(0x80000000);
133 if (maxei
< 0x80000007) { /* Any powernow info ? */
135 printk(KERN_INFO PFX
"No powernow capabilities detected\n");
140 if ((c
->x86_model
== 6) && (c
->x86_mask
== 0)) {
141 printk(KERN_INFO PFX
"K7 660[A0] core detected, "
142 "enabling errata workarounds\n");
146 cpuid(0x80000007, &eax
, &ebx
, &ecx
, &edx
);
148 /* Check we can actually do something before we say anything.*/
149 if (!(edx
& (1 << 1 | 1 << 2)))
152 printk(KERN_INFO PFX
"PowerNOW! Technology present. Can scale: ");
159 if ((edx
& (1 << 1 | 1 << 2)) == 0x6)
171 static void invalidate_entry(unsigned int entry
)
173 powernow_table
[entry
].frequency
= CPUFREQ_ENTRY_INVALID
;
176 static int get_ranges(unsigned char *pst
)
182 powernow_table
= kzalloc((sizeof(struct cpufreq_frequency_table
) *
183 (number_scales
+ 1)), GFP_KERNEL
);
187 for (j
= 0 ; j
< number_scales
; j
++) {
190 powernow_table
[j
].frequency
= (fsb
* fid_codes
[fid
]) / 10;
191 powernow_table
[j
].index
= fid
; /* lower 8 bits */
193 speed
= powernow_table
[j
].frequency
;
195 if ((fid_codes
[fid
] % 10) == 5) {
196 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
202 if (speed
< minimum_speed
)
203 minimum_speed
= speed
;
204 if (speed
> maximum_speed
)
205 maximum_speed
= speed
;
208 powernow_table
[j
].index
|= (vid
<< 8); /* upper 8 bits */
210 dprintk(" FID: 0x%x (%d.%dx [%dMHz]) "
211 "VID: 0x%x (%d.%03dV)\n", fid
, fid_codes
[fid
] / 10,
212 fid_codes
[fid
] % 10, speed
/1000, vid
,
213 mobile_vid_table
[vid
]/1000,
214 mobile_vid_table
[vid
]%1000);
216 powernow_table
[number_scales
].frequency
= CPUFREQ_TABLE_END
;
217 powernow_table
[number_scales
].index
= 0;
223 static void change_FID(int fid
)
225 union msr_fidvidctl fidvidctl
;
227 rdmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
228 if (fidvidctl
.bits
.FID
!= fid
) {
229 fidvidctl
.bits
.SGTC
= latency
;
230 fidvidctl
.bits
.FID
= fid
;
231 fidvidctl
.bits
.VIDC
= 0;
232 fidvidctl
.bits
.FIDC
= 1;
233 wrmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
238 static void change_VID(int vid
)
240 union msr_fidvidctl fidvidctl
;
242 rdmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
243 if (fidvidctl
.bits
.VID
!= vid
) {
244 fidvidctl
.bits
.SGTC
= latency
;
245 fidvidctl
.bits
.VID
= vid
;
246 fidvidctl
.bits
.FIDC
= 0;
247 fidvidctl
.bits
.VIDC
= 1;
248 wrmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
253 static void change_speed(unsigned int index
)
256 struct cpufreq_freqs freqs
;
257 union msr_fidvidstatus fidvidstatus
;
260 /* fid are the lower 8 bits of the index we stored into
261 * the cpufreq frequency table in powernow_decode_bios,
262 * vid are the upper 8 bits.
265 fid
= powernow_table
[index
].index
& 0xFF;
266 vid
= (powernow_table
[index
].index
& 0xFF00) >> 8;
270 rdmsrl(MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
271 cfid
= fidvidstatus
.bits
.CFID
;
272 freqs
.old
= fsb
* fid_codes
[cfid
] / 10;
274 freqs
.new = powernow_table
[index
].frequency
;
276 cpufreq_notify_transition(&freqs
, CPUFREQ_PRECHANGE
);
278 /* Now do the magic poking into the MSRs. */
280 if (have_a0
== 1) /* A0 errata 5 */
283 if (freqs
.old
> freqs
.new) {
284 /* Going down, so change FID first */
288 /* Going up, so change VID first */
297 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
301 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
303 static struct acpi_processor_performance
*acpi_processor_perf
;
305 static int powernow_acpi_init(void)
309 union powernow_acpi_control_t pc
;
311 if (acpi_processor_perf
!= NULL
&& powernow_table
!= NULL
) {
316 acpi_processor_perf
= kzalloc(sizeof(struct acpi_processor_performance
),
318 if (!acpi_processor_perf
) {
323 if (!alloc_cpumask_var(&acpi_processor_perf
->shared_cpu_map
,
329 if (acpi_processor_register_performance(acpi_processor_perf
, 0)) {
334 if (acpi_processor_perf
->control_register
.space_id
!=
335 ACPI_ADR_SPACE_FIXED_HARDWARE
) {
340 if (acpi_processor_perf
->status_register
.space_id
!=
341 ACPI_ADR_SPACE_FIXED_HARDWARE
) {
346 number_scales
= acpi_processor_perf
->state_count
;
348 if (number_scales
< 2) {
353 powernow_table
= kzalloc((sizeof(struct cpufreq_frequency_table
) *
354 (number_scales
+ 1)), GFP_KERNEL
);
355 if (!powernow_table
) {
360 pc
.val
= (unsigned long) acpi_processor_perf
->states
[0].control
;
361 for (i
= 0; i
< number_scales
; i
++) {
363 struct acpi_processor_px
*state
=
364 &acpi_processor_perf
->states
[i
];
365 unsigned int speed
, speed_mhz
;
367 pc
.val
= (unsigned long) state
->control
;
368 dprintk("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
370 (u32
) state
->core_frequency
,
372 (u32
) state
->transition_latency
,
373 (u32
) state
->control
,
379 powernow_table
[i
].frequency
= fsb
* fid_codes
[fid
] / 10;
380 powernow_table
[i
].index
= fid
; /* lower 8 bits */
381 powernow_table
[i
].index
|= (vid
<< 8); /* upper 8 bits */
383 speed
= powernow_table
[i
].frequency
;
384 speed_mhz
= speed
/ 1000;
386 /* processor_perflib will multiply the MHz value by 1000 to
387 * get a KHz value (e.g. 1266000). However, powernow-k7 works
388 * with true KHz values (e.g. 1266768). To ensure that all
389 * powernow frequencies are available, we must ensure that
390 * ACPI doesn't restrict them, so we round up the MHz value
391 * to ensure that perflib's computed KHz value is greater than
392 * or equal to powernow's KHz value.
394 if (speed
% 1000 > 0)
397 if ((fid_codes
[fid
] % 10) == 5) {
402 dprintk(" FID: 0x%x (%d.%dx [%dMHz]) "
403 "VID: 0x%x (%d.%03dV)\n", fid
, fid_codes
[fid
] / 10,
404 fid_codes
[fid
] % 10, speed_mhz
, vid
,
405 mobile_vid_table
[vid
]/1000,
406 mobile_vid_table
[vid
]%1000);
408 if (state
->core_frequency
!= speed_mhz
) {
409 state
->core_frequency
= speed_mhz
;
410 dprintk(" Corrected ACPI frequency to %d\n",
414 if (latency
< pc
.bits
.sgtc
)
415 latency
= pc
.bits
.sgtc
;
417 if (speed
< minimum_speed
)
418 minimum_speed
= speed
;
419 if (speed
> maximum_speed
)
420 maximum_speed
= speed
;
423 powernow_table
[i
].frequency
= CPUFREQ_TABLE_END
;
424 powernow_table
[i
].index
= 0;
426 /* notify BIOS that we exist */
427 acpi_processor_notify_smm(THIS_MODULE
);
432 acpi_processor_unregister_performance(acpi_processor_perf
, 0);
434 free_cpumask_var(acpi_processor_perf
->shared_cpu_map
);
436 kfree(acpi_processor_perf
);
438 printk(KERN_WARNING PFX
"ACPI perflib can not be used on "
440 acpi_processor_perf
= NULL
;
444 static int powernow_acpi_init(void)
446 printk(KERN_INFO PFX
"no support for ACPI processor found."
447 " Please recompile your kernel with ACPI processor\n");
452 static void print_pst_entry(struct pst_s
*pst
, unsigned int j
)
454 dprintk("PST:%d (@%p)\n", j
, pst
);
455 dprintk(" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
456 pst
->cpuid
, pst
->fsbspeed
, pst
->maxfid
, pst
->startvid
);
459 static int powernow_decode_bios(int maxfid
, int startvid
)
468 etuple
= cpuid_eax(0x80000001);
470 for (i
= 0xC0000; i
< 0xffff0 ; i
+= 16) {
474 if (memcmp(p
, "AMDK7PNOW!", 10) == 0) {
475 dprintk("Found PSB header at %p\n", p
);
476 psb
= (struct psb_s
*) p
;
477 dprintk("Table version: 0x%x\n", psb
->tableversion
);
478 if (psb
->tableversion
!= 0x12) {
479 printk(KERN_INFO PFX
"Sorry, only v1.2 tables"
480 " supported right now\n");
484 dprintk("Flags: 0x%x\n", psb
->flags
);
485 if ((psb
->flags
& 1) == 0)
486 dprintk("Mobile voltage regulator\n");
488 dprintk("Desktop voltage regulator\n");
490 latency
= psb
->settlingtime
;
492 printk(KERN_INFO PFX
"BIOS set settling time "
493 "to %d microseconds. "
494 "Should be at least 100. "
495 "Correcting.\n", latency
);
498 dprintk("Settling Time: %d microseconds.\n",
500 dprintk("Has %d PST tables. (Only dumping ones "
501 "relevant to this CPU).\n",
504 p
+= sizeof(struct psb_s
);
506 pst
= (struct pst_s
*) p
;
508 for (j
= 0; j
< psb
->numpst
; j
++) {
509 pst
= (struct pst_s
*) p
;
510 number_scales
= pst
->numpstates
;
512 if ((etuple
== pst
->cpuid
) &&
513 check_fsb(pst
->fsbspeed
) &&
514 (maxfid
== pst
->maxfid
) &&
515 (startvid
== pst
->startvid
)) {
516 print_pst_entry(pst
, j
);
517 p
= (char *)pst
+ sizeof(struct pst_s
);
522 p
= (char *)pst
+ sizeof(struct pst_s
);
523 for (k
= 0; k
< number_scales
; k
++)
527 printk(KERN_INFO PFX
"No PST tables match this cpuid "
529 printk(KERN_INFO PFX
"This is indicative of a broken "
541 static int powernow_target(struct cpufreq_policy
*policy
,
542 unsigned int target_freq
,
543 unsigned int relation
)
545 unsigned int newstate
;
547 if (cpufreq_frequency_table_target(policy
, powernow_table
, target_freq
,
548 relation
, &newstate
))
551 change_speed(newstate
);
557 static int powernow_verify(struct cpufreq_policy
*policy
)
559 return cpufreq_frequency_table_verify(policy
, powernow_table
);
563 * We use the fact that the bus frequency is somehow
564 * a multiple of 100000/3 khz, then we compute sgtc according
566 * That way, we match more how AMD thinks all of that work.
567 * We will then get the same kind of behaviour already tested under
568 * the "well-known" other OS.
570 static int __init
fixup_sgtc(void)
581 sgtc
= 100 * m
* latency
;
583 if (sgtc
> 0xfffff) {
584 printk(KERN_WARNING PFX
"SGTC too large %d\n", sgtc
);
590 static unsigned int powernow_get(unsigned int cpu
)
592 union msr_fidvidstatus fidvidstatus
;
597 rdmsrl(MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
598 cfid
= fidvidstatus
.bits
.CFID
;
600 return fsb
* fid_codes
[cfid
] / 10;
604 static int __init
acer_cpufreq_pst(const struct dmi_system_id
*d
)
606 printk(KERN_WARNING PFX
607 "%s laptop with broken PST tables in BIOS detected.\n",
609 printk(KERN_WARNING PFX
610 "You need to downgrade to 3A21 (09/09/2002), or try a newer "
611 "BIOS than 3A71 (01/20/2003)\n");
612 printk(KERN_WARNING PFX
613 "cpufreq scaling has been disabled as a result of this.\n");
618 * Some Athlon laptops have really fucked PST tables.
619 * A BIOS update is all that can save them.
620 * Mention this, and disable cpufreq.
622 static struct dmi_system_id __initdata powernow_dmi_table
[] = {
624 .callback
= acer_cpufreq_pst
,
625 .ident
= "Acer Aspire",
627 DMI_MATCH(DMI_SYS_VENDOR
, "Insyde Software"),
628 DMI_MATCH(DMI_BIOS_VERSION
, "3A71"),
634 static int __init
powernow_cpu_init(struct cpufreq_policy
*policy
)
636 union msr_fidvidstatus fidvidstatus
;
639 if (policy
->cpu
!= 0)
642 rdmsrl(MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
644 recalibrate_cpu_khz();
646 fsb
= (10 * cpu_khz
) / fid_codes
[fidvidstatus
.bits
.CFID
];
648 printk(KERN_WARNING PFX
"can not determine bus frequency\n");
651 dprintk("FSB: %3dMHz\n", fsb
/1000);
653 if (dmi_check_system(powernow_dmi_table
) || acpi_force
) {
654 printk(KERN_INFO PFX
"PSB/PST known to be broken. "
655 "Trying ACPI instead\n");
656 result
= powernow_acpi_init();
658 result
= powernow_decode_bios(fidvidstatus
.bits
.MFID
,
659 fidvidstatus
.bits
.SVID
);
661 printk(KERN_INFO PFX
"Trying ACPI perflib\n");
665 result
= powernow_acpi_init();
668 "ACPI and legacy methods failed\n");
671 /* SGTC use the bus clock as timer */
672 latency
= fixup_sgtc();
673 printk(KERN_INFO PFX
"SGTC: %d\n", latency
);
680 printk(KERN_INFO PFX
"Minimum speed %d MHz. Maximum speed %d MHz.\n",
681 minimum_speed
/1000, maximum_speed
/1000);
683 policy
->cpuinfo
.transition_latency
=
684 cpufreq_scale(2000000UL, fsb
, latency
);
686 policy
->cur
= powernow_get(0);
688 cpufreq_frequency_table_get_attr(powernow_table
, policy
->cpu
);
690 return cpufreq_frequency_table_cpuinfo(policy
, powernow_table
);
693 static int powernow_cpu_exit(struct cpufreq_policy
*policy
)
695 cpufreq_frequency_table_put_attr(policy
->cpu
);
697 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
698 if (acpi_processor_perf
) {
699 acpi_processor_unregister_performance(acpi_processor_perf
, 0);
700 free_cpumask_var(acpi_processor_perf
->shared_cpu_map
);
701 kfree(acpi_processor_perf
);
705 kfree(powernow_table
);
709 static struct freq_attr
*powernow_table_attr
[] = {
710 &cpufreq_freq_attr_scaling_available_freqs
,
714 static struct cpufreq_driver powernow_driver
= {
715 .verify
= powernow_verify
,
716 .target
= powernow_target
,
718 .init
= powernow_cpu_init
,
719 .exit
= powernow_cpu_exit
,
720 .name
= "powernow-k7",
721 .owner
= THIS_MODULE
,
722 .attr
= powernow_table_attr
,
725 static int __init
powernow_init(void)
727 if (check_powernow() == 0)
729 return cpufreq_register_driver(&powernow_driver
);
733 static void __exit
powernow_exit(void)
735 cpufreq_unregister_driver(&powernow_driver
);
738 module_param(acpi_force
, int, 0444);
739 MODULE_PARM_DESC(acpi_force
, "Force ACPI to be used.");
741 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
742 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
743 MODULE_LICENSE("GPL");
745 late_initcall(powernow_init
);
746 module_exit(powernow_exit
);