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.
9 * Errata 5: Processor may fail to execute a FID/VID change in presence of interrupt.
10 * - We cli/sti on stepping A0 CPUs around the FID/VID transition.
11 * Errata 15: Processors with half frequency multipliers may hang upon wakeup from disconnect.
12 * - We disable half multipliers if ACPI is used on A0 stepping CPUs.
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/moduleparam.h>
18 #include <linux/init.h>
19 #include <linux/cpufreq.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
22 #include <linux/dmi.h>
25 #include <asm/timer.h>
26 #include <asm/timex.h>
28 #include <asm/system.h>
30 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
31 #include <linux/acpi.h>
32 #include <acpi/processor.h>
35 #include "powernow-k7.h"
37 #define PFX "powernow: "
57 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
58 union powernow_acpi_control_t
{
69 #ifdef CONFIG_CPU_FREQ_DEBUG
70 /* divide by 1000 to get VCore voltage in V. */
71 static const int mobile_vid_table
[32] = {
72 2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
73 1600, 1550, 1500, 1450, 1400, 1350, 1300, 0,
74 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
75 1075, 1050, 1025, 1000, 975, 950, 925, 0,
79 /* divide by 10 to get FID. */
80 static const int fid_codes
[32] = {
81 110, 115, 120, 125, 50, 55, 60, 65,
82 70, 75, 80, 85, 90, 95, 100, 105,
83 30, 190, 40, 200, 130, 135, 140, 210,
84 150, 225, 160, 165, 170, 180, -1, -1,
87 /* This parameter is used in order to force ACPI instead of legacy method for
88 * configuration purpose.
91 static int acpi_force
;
93 static struct cpufreq_frequency_table
*powernow_table
;
95 static unsigned int can_scale_bus
;
96 static unsigned int can_scale_vid
;
97 static unsigned int minimum_speed
=-1;
98 static unsigned int maximum_speed
;
99 static unsigned int number_scales
;
100 static unsigned int fsb
;
101 static unsigned int latency
;
104 #define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "powernow-k7", msg)
106 static int check_fsb(unsigned int fsbspeed
)
109 unsigned int f
= fsb
/ 1000;
111 delta
= (fsbspeed
> f
) ? fsbspeed
- f
: f
- fsbspeed
;
115 static int check_powernow(void)
117 struct cpuinfo_x86
*c
= &cpu_data(0);
118 unsigned int maxei
, eax
, ebx
, ecx
, edx
;
120 if ((c
->x86_vendor
!= X86_VENDOR_AMD
) || (c
->x86
!=6)) {
122 printk (KERN_INFO PFX
"This module only works with AMD K7 CPUs\n");
127 /* Get maximum capabilities */
128 maxei
= cpuid_eax (0x80000000);
129 if (maxei
< 0x80000007) { /* Any powernow info ? */
131 printk (KERN_INFO PFX
"No powernow capabilities detected\n");
136 if ((c
->x86_model
== 6) && (c
->x86_mask
== 0)) {
137 printk (KERN_INFO PFX
"K7 660[A0] core detected, enabling errata workarounds\n");
141 cpuid(0x80000007, &eax
, &ebx
, &ecx
, &edx
);
143 /* Check we can actually do something before we say anything.*/
144 if (!(edx
& (1 << 1 | 1 << 2)))
147 printk (KERN_INFO PFX
"PowerNOW! Technology present. Can scale: ");
150 printk ("frequency");
154 if ((edx
& (1 << 1 | 1 << 2)) == 0x6)
167 static int get_ranges (unsigned char *pst
)
173 powernow_table
= kzalloc((sizeof(struct cpufreq_frequency_table
) * (number_scales
+ 1)), GFP_KERNEL
);
177 for (j
=0 ; j
< number_scales
; j
++) {
180 powernow_table
[j
].frequency
= (fsb
* fid_codes
[fid
]) / 10;
181 powernow_table
[j
].index
= fid
; /* lower 8 bits */
183 speed
= powernow_table
[j
].frequency
;
185 if ((fid_codes
[fid
] % 10)==5) {
186 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
188 powernow_table
[j
].frequency
= CPUFREQ_ENTRY_INVALID
;
192 if (speed
< minimum_speed
)
193 minimum_speed
= speed
;
194 if (speed
> maximum_speed
)
195 maximum_speed
= speed
;
198 powernow_table
[j
].index
|= (vid
<< 8); /* upper 8 bits */
200 dprintk (" FID: 0x%x (%d.%dx [%dMHz]) "
201 "VID: 0x%x (%d.%03dV)\n", fid
, fid_codes
[fid
] / 10,
202 fid_codes
[fid
] % 10, speed
/1000, vid
,
203 mobile_vid_table
[vid
]/1000,
204 mobile_vid_table
[vid
]%1000);
206 powernow_table
[number_scales
].frequency
= CPUFREQ_TABLE_END
;
207 powernow_table
[number_scales
].index
= 0;
213 static void change_FID(int fid
)
215 union msr_fidvidctl fidvidctl
;
217 rdmsrl (MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
218 if (fidvidctl
.bits
.FID
!= fid
) {
219 fidvidctl
.bits
.SGTC
= latency
;
220 fidvidctl
.bits
.FID
= fid
;
221 fidvidctl
.bits
.VIDC
= 0;
222 fidvidctl
.bits
.FIDC
= 1;
223 wrmsrl (MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
228 static void change_VID(int vid
)
230 union msr_fidvidctl fidvidctl
;
232 rdmsrl (MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
233 if (fidvidctl
.bits
.VID
!= vid
) {
234 fidvidctl
.bits
.SGTC
= latency
;
235 fidvidctl
.bits
.VID
= vid
;
236 fidvidctl
.bits
.FIDC
= 0;
237 fidvidctl
.bits
.VIDC
= 1;
238 wrmsrl (MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
243 static void change_speed (unsigned int index
)
246 struct cpufreq_freqs freqs
;
247 union msr_fidvidstatus fidvidstatus
;
250 /* fid are the lower 8 bits of the index we stored into
251 * the cpufreq frequency table in powernow_decode_bios,
252 * vid are the upper 8 bits.
255 fid
= powernow_table
[index
].index
& 0xFF;
256 vid
= (powernow_table
[index
].index
& 0xFF00) >> 8;
260 rdmsrl (MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
261 cfid
= fidvidstatus
.bits
.CFID
;
262 freqs
.old
= fsb
* fid_codes
[cfid
] / 10;
264 freqs
.new = powernow_table
[index
].frequency
;
266 cpufreq_notify_transition(&freqs
, CPUFREQ_PRECHANGE
);
268 /* Now do the magic poking into the MSRs. */
270 if (have_a0
== 1) /* A0 errata 5 */
273 if (freqs
.old
> freqs
.new) {
274 /* Going down, so change FID first */
278 /* Going up, so change VID first */
287 cpufreq_notify_transition(&freqs
, CPUFREQ_POSTCHANGE
);
291 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
293 static struct acpi_processor_performance
*acpi_processor_perf
;
295 static int powernow_acpi_init(void)
299 union powernow_acpi_control_t pc
;
301 if (acpi_processor_perf
!= NULL
&& powernow_table
!= NULL
) {
306 acpi_processor_perf
= kzalloc(sizeof(struct acpi_processor_performance
),
308 if (!acpi_processor_perf
) {
313 if (!alloc_cpumask_var(&acpi_processor_perf
->shared_cpu_map
,
319 if (acpi_processor_register_performance(acpi_processor_perf
, 0)) {
324 if (acpi_processor_perf
->control_register
.space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
) {
329 if (acpi_processor_perf
->status_register
.space_id
!= ACPI_ADR_SPACE_FIXED_HARDWARE
) {
334 number_scales
= acpi_processor_perf
->state_count
;
336 if (number_scales
< 2) {
341 powernow_table
= kzalloc((number_scales
+ 1) * (sizeof(struct cpufreq_frequency_table
)), GFP_KERNEL
);
342 if (!powernow_table
) {
347 pc
.val
= (unsigned long) acpi_processor_perf
->states
[0].control
;
348 for (i
= 0; i
< number_scales
; i
++) {
350 struct acpi_processor_px
*state
=
351 &acpi_processor_perf
->states
[i
];
352 unsigned int speed
, speed_mhz
;
354 pc
.val
= (unsigned long) state
->control
;
355 dprintk ("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
357 (u32
) state
->core_frequency
,
359 (u32
) state
->transition_latency
,
360 (u32
) state
->control
,
366 powernow_table
[i
].frequency
= fsb
* fid_codes
[fid
] / 10;
367 powernow_table
[i
].index
= fid
; /* lower 8 bits */
368 powernow_table
[i
].index
|= (vid
<< 8); /* upper 8 bits */
370 speed
= powernow_table
[i
].frequency
;
371 speed_mhz
= speed
/ 1000;
373 /* processor_perflib will multiply the MHz value by 1000 to
374 * get a KHz value (e.g. 1266000). However, powernow-k7 works
375 * with true KHz values (e.g. 1266768). To ensure that all
376 * powernow frequencies are available, we must ensure that
377 * ACPI doesn't restrict them, so we round up the MHz value
378 * to ensure that perflib's computed KHz value is greater than
379 * or equal to powernow's KHz value.
381 if (speed
% 1000 > 0)
384 if ((fid_codes
[fid
] % 10)==5) {
386 powernow_table
[i
].frequency
= CPUFREQ_ENTRY_INVALID
;
389 dprintk (" FID: 0x%x (%d.%dx [%dMHz]) "
390 "VID: 0x%x (%d.%03dV)\n", fid
, fid_codes
[fid
] / 10,
391 fid_codes
[fid
] % 10, speed_mhz
, vid
,
392 mobile_vid_table
[vid
]/1000,
393 mobile_vid_table
[vid
]%1000);
395 if (state
->core_frequency
!= speed_mhz
) {
396 state
->core_frequency
= speed_mhz
;
397 dprintk(" Corrected ACPI frequency to %d\n",
401 if (latency
< pc
.bits
.sgtc
)
402 latency
= pc
.bits
.sgtc
;
404 if (speed
< minimum_speed
)
405 minimum_speed
= speed
;
406 if (speed
> maximum_speed
)
407 maximum_speed
= speed
;
410 powernow_table
[i
].frequency
= CPUFREQ_TABLE_END
;
411 powernow_table
[i
].index
= 0;
413 /* notify BIOS that we exist */
414 acpi_processor_notify_smm(THIS_MODULE
);
419 acpi_processor_unregister_performance(acpi_processor_perf
, 0);
421 free_cpumask_var(acpi_processor_perf
->shared_cpu_map
);
423 kfree(acpi_processor_perf
);
425 printk(KERN_WARNING PFX
"ACPI perflib can not be used in this platform\n");
426 acpi_processor_perf
= NULL
;
430 static int powernow_acpi_init(void)
432 printk(KERN_INFO PFX
"no support for ACPI processor found."
433 " Please recompile your kernel with ACPI processor\n");
438 static int powernow_decode_bios (int maxfid
, int startvid
)
447 etuple
= cpuid_eax(0x80000001);
449 for (i
=0xC0000; i
< 0xffff0 ; i
+=16) {
453 if (memcmp(p
, "AMDK7PNOW!", 10) == 0){
454 dprintk ("Found PSB header at %p\n", p
);
455 psb
= (struct psb_s
*) p
;
456 dprintk ("Table version: 0x%x\n", psb
->tableversion
);
457 if (psb
->tableversion
!= 0x12) {
458 printk (KERN_INFO PFX
"Sorry, only v1.2 tables supported right now\n");
462 dprintk ("Flags: 0x%x\n", psb
->flags
);
463 if ((psb
->flags
& 1)==0) {
464 dprintk ("Mobile voltage regulator\n");
466 dprintk ("Desktop voltage regulator\n");
469 latency
= psb
->settlingtime
;
471 printk(KERN_INFO PFX
"BIOS set settling time to %d microseconds. "
472 "Should be at least 100. Correcting.\n", latency
);
475 dprintk ("Settling Time: %d microseconds.\n", psb
->settlingtime
);
476 dprintk ("Has %d PST tables. (Only dumping ones relevant to this CPU).\n", psb
->numpst
);
478 p
+= sizeof (struct psb_s
);
480 pst
= (struct pst_s
*) p
;
482 for (j
=0; j
<psb
->numpst
; j
++) {
483 pst
= (struct pst_s
*) p
;
484 number_scales
= pst
->numpstates
;
486 if ((etuple
== pst
->cpuid
) && check_fsb(pst
->fsbspeed
) &&
487 (maxfid
==pst
->maxfid
) && (startvid
==pst
->startvid
))
489 dprintk ("PST:%d (@%p)\n", j
, pst
);
490 dprintk (" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
491 pst
->cpuid
, pst
->fsbspeed
, pst
->maxfid
, pst
->startvid
);
493 ret
= get_ranges ((char *) pst
+ sizeof (struct pst_s
));
497 p
= (char *) pst
+ sizeof (struct pst_s
);
498 for (k
=0; k
<number_scales
; k
++)
502 printk (KERN_INFO PFX
"No PST tables match this cpuid (0x%x)\n", etuple
);
503 printk (KERN_INFO PFX
"This is indicative of a broken BIOS.\n");
514 static int powernow_target (struct cpufreq_policy
*policy
,
515 unsigned int target_freq
,
516 unsigned int relation
)
518 unsigned int newstate
;
520 if (cpufreq_frequency_table_target(policy
, powernow_table
, target_freq
, relation
, &newstate
))
523 change_speed(newstate
);
529 static int powernow_verify (struct cpufreq_policy
*policy
)
531 return cpufreq_frequency_table_verify(policy
, powernow_table
);
535 * We use the fact that the bus frequency is somehow
536 * a multiple of 100000/3 khz, then we compute sgtc according
538 * That way, we match more how AMD thinks all of that work.
539 * We will then get the same kind of behaviour already tested under
540 * the "well-known" other OS.
542 static int __init
fixup_sgtc(void)
553 sgtc
= 100 * m
* latency
;
555 if (sgtc
> 0xfffff) {
556 printk(KERN_WARNING PFX
"SGTC too large %d\n", sgtc
);
562 static unsigned int powernow_get(unsigned int cpu
)
564 union msr_fidvidstatus fidvidstatus
;
569 rdmsrl (MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
570 cfid
= fidvidstatus
.bits
.CFID
;
572 return (fsb
* fid_codes
[cfid
] / 10);
576 static int __init
acer_cpufreq_pst(const struct dmi_system_id
*d
)
578 printk(KERN_WARNING
"%s laptop with broken PST tables in BIOS detected.\n", d
->ident
);
579 printk(KERN_WARNING
"You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n");
580 printk(KERN_WARNING
"cpufreq scaling has been disabled as a result of this.\n");
585 * Some Athlon laptops have really fucked PST tables.
586 * A BIOS update is all that can save them.
587 * Mention this, and disable cpufreq.
589 static struct dmi_system_id __initdata powernow_dmi_table
[] = {
591 .callback
= acer_cpufreq_pst
,
592 .ident
= "Acer Aspire",
594 DMI_MATCH(DMI_SYS_VENDOR
, "Insyde Software"),
595 DMI_MATCH(DMI_BIOS_VERSION
, "3A71"),
601 static int __init
powernow_cpu_init (struct cpufreq_policy
*policy
)
603 union msr_fidvidstatus fidvidstatus
;
606 if (policy
->cpu
!= 0)
609 rdmsrl (MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
611 recalibrate_cpu_khz();
613 fsb
= (10 * cpu_khz
) / fid_codes
[fidvidstatus
.bits
.CFID
];
615 printk(KERN_WARNING PFX
"can not determine bus frequency\n");
618 dprintk("FSB: %3dMHz\n", fsb
/1000);
620 if (dmi_check_system(powernow_dmi_table
) || acpi_force
) {
621 printk (KERN_INFO PFX
"PSB/PST known to be broken. Trying ACPI instead\n");
622 result
= powernow_acpi_init();
624 result
= powernow_decode_bios(fidvidstatus
.bits
.MFID
, fidvidstatus
.bits
.SVID
);
626 printk (KERN_INFO PFX
"Trying ACPI perflib\n");
630 result
= powernow_acpi_init();
632 printk (KERN_INFO PFX
"ACPI and legacy methods failed\n");
633 printk (KERN_INFO PFX
"See http://www.codemonkey.org.uk/projects/cpufreq/powernow-k7.html\n");
636 /* SGTC use the bus clock as timer */
637 latency
= fixup_sgtc();
638 printk(KERN_INFO PFX
"SGTC: %d\n", latency
);
645 printk (KERN_INFO PFX
"Minimum speed %d MHz. Maximum speed %d MHz.\n",
646 minimum_speed
/1000, maximum_speed
/1000);
648 policy
->cpuinfo
.transition_latency
= cpufreq_scale(2000000UL, fsb
, latency
);
650 policy
->cur
= powernow_get(0);
652 cpufreq_frequency_table_get_attr(powernow_table
, policy
->cpu
);
654 return cpufreq_frequency_table_cpuinfo(policy
, powernow_table
);
657 static int powernow_cpu_exit (struct cpufreq_policy
*policy
) {
658 cpufreq_frequency_table_put_attr(policy
->cpu
);
660 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
661 if (acpi_processor_perf
) {
662 acpi_processor_unregister_performance(acpi_processor_perf
, 0);
663 free_cpumask_var(acpi_processor_perf
->shared_cpu_map
);
664 kfree(acpi_processor_perf
);
668 kfree(powernow_table
);
672 static struct freq_attr
* powernow_table_attr
[] = {
673 &cpufreq_freq_attr_scaling_available_freqs
,
677 static struct cpufreq_driver powernow_driver
= {
678 .verify
= powernow_verify
,
679 .target
= powernow_target
,
681 .init
= powernow_cpu_init
,
682 .exit
= powernow_cpu_exit
,
683 .name
= "powernow-k7",
684 .owner
= THIS_MODULE
,
685 .attr
= powernow_table_attr
,
688 static int __init
powernow_init (void)
690 if (check_powernow()==0)
692 return cpufreq_register_driver(&powernow_driver
);
696 static void __exit
powernow_exit (void)
698 cpufreq_unregister_driver(&powernow_driver
);
701 module_param(acpi_force
, int, 0444);
702 MODULE_PARM_DESC(acpi_force
, "Force ACPI to be used.");
704 MODULE_AUTHOR ("Dave Jones <davej@redhat.com>");
705 MODULE_DESCRIPTION ("Powernow driver for AMD K7 processors.");
706 MODULE_LICENSE ("GPL");
708 late_initcall(powernow_init
);
709 module_exit(powernow_exit
);