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/cpu_device_id.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 /* divide by 1000 to get VCore voltage in V. */
72 static const int mobile_vid_table
[32] = {
73 2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
74 1600, 1550, 1500, 1450, 1400, 1350, 1300, 0,
75 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
76 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 static int check_fsb(unsigned int fsbspeed
)
107 unsigned int f
= fsb
/ 1000;
109 delta
= (fsbspeed
> f
) ? fsbspeed
- f
: f
- fsbspeed
;
113 static const struct x86_cpu_id powernow_k7_cpuids
[] = {
114 { X86_VENDOR_AMD
, 6, },
117 MODULE_DEVICE_TABLE(x86cpu
, powernow_k7_cpuids
);
119 static int check_powernow(void)
121 struct cpuinfo_x86
*c
= &cpu_data(0);
122 unsigned int maxei
, eax
, ebx
, ecx
, edx
;
124 if (!x86_match_cpu(powernow_k7_cpuids
))
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, "
138 "enabling errata workarounds\n");
142 cpuid(0x80000007, &eax
, &ebx
, &ecx
, &edx
);
144 /* Check we can actually do something before we say anything.*/
145 if (!(edx
& (1 << 1 | 1 << 2)))
148 printk(KERN_INFO PFX
"PowerNOW! Technology present. Can scale: ");
155 if ((edx
& (1 << 1 | 1 << 2)) == 0x6)
167 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
168 static void invalidate_entry(unsigned int entry
)
170 powernow_table
[entry
].frequency
= CPUFREQ_ENTRY_INVALID
;
174 static int get_ranges(unsigned char *pst
)
180 powernow_table
= kzalloc((sizeof(*powernow_table
) *
181 (number_scales
+ 1)), GFP_KERNEL
);
185 for (j
= 0 ; j
< number_scales
; j
++) {
188 powernow_table
[j
].frequency
= (fsb
* fid_codes
[fid
]) / 10;
189 powernow_table
[j
].driver_data
= fid
; /* lower 8 bits */
191 speed
= powernow_table
[j
].frequency
;
193 if ((fid_codes
[fid
] % 10) == 5) {
194 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
200 if (speed
< minimum_speed
)
201 minimum_speed
= speed
;
202 if (speed
> maximum_speed
)
203 maximum_speed
= speed
;
206 powernow_table
[j
].driver_data
|= (vid
<< 8); /* upper 8 bits */
208 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
209 "VID: 0x%x (%d.%03dV)\n", fid
, fid_codes
[fid
] / 10,
210 fid_codes
[fid
] % 10, speed
/1000, vid
,
211 mobile_vid_table
[vid
]/1000,
212 mobile_vid_table
[vid
]%1000);
214 powernow_table
[number_scales
].frequency
= CPUFREQ_TABLE_END
;
215 powernow_table
[number_scales
].driver_data
= 0;
221 static void change_FID(int fid
)
223 union msr_fidvidctl fidvidctl
;
225 rdmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
226 if (fidvidctl
.bits
.FID
!= fid
) {
227 fidvidctl
.bits
.SGTC
= latency
;
228 fidvidctl
.bits
.FID
= fid
;
229 fidvidctl
.bits
.VIDC
= 0;
230 fidvidctl
.bits
.FIDC
= 1;
231 wrmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
236 static void change_VID(int vid
)
238 union msr_fidvidctl fidvidctl
;
240 rdmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
241 if (fidvidctl
.bits
.VID
!= vid
) {
242 fidvidctl
.bits
.SGTC
= latency
;
243 fidvidctl
.bits
.VID
= vid
;
244 fidvidctl
.bits
.FIDC
= 0;
245 fidvidctl
.bits
.VIDC
= 1;
246 wrmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
251 static void change_speed(struct cpufreq_policy
*policy
, unsigned int index
)
254 struct cpufreq_freqs freqs
;
255 union msr_fidvidstatus fidvidstatus
;
258 /* fid are the lower 8 bits of the index we stored into
259 * the cpufreq frequency table in powernow_decode_bios,
260 * vid are the upper 8 bits.
263 fid
= powernow_table
[index
].driver_data
& 0xFF;
264 vid
= (powernow_table
[index
].driver_data
& 0xFF00) >> 8;
266 rdmsrl(MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
267 cfid
= fidvidstatus
.bits
.CFID
;
268 freqs
.old
= fsb
* fid_codes
[cfid
] / 10;
270 freqs
.new = powernow_table
[index
].frequency
;
272 cpufreq_notify_transition(policy
, &freqs
, CPUFREQ_PRECHANGE
);
274 /* Now do the magic poking into the MSRs. */
276 if (have_a0
== 1) /* A0 errata 5 */
279 if (freqs
.old
> freqs
.new) {
280 /* Going down, so change FID first */
284 /* Going up, so change VID first */
293 cpufreq_notify_transition(policy
, &freqs
, CPUFREQ_POSTCHANGE
);
297 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
299 static struct acpi_processor_performance
*acpi_processor_perf
;
301 static int powernow_acpi_init(void)
305 union powernow_acpi_control_t pc
;
307 if (acpi_processor_perf
!= NULL
&& powernow_table
!= NULL
) {
312 acpi_processor_perf
= kzalloc(sizeof(*acpi_processor_perf
), GFP_KERNEL
);
313 if (!acpi_processor_perf
) {
318 if (!zalloc_cpumask_var(&acpi_processor_perf
->shared_cpu_map
,
324 if (acpi_processor_register_performance(acpi_processor_perf
, 0)) {
329 if (acpi_processor_perf
->control_register
.space_id
!=
330 ACPI_ADR_SPACE_FIXED_HARDWARE
) {
335 if (acpi_processor_perf
->status_register
.space_id
!=
336 ACPI_ADR_SPACE_FIXED_HARDWARE
) {
341 number_scales
= acpi_processor_perf
->state_count
;
343 if (number_scales
< 2) {
348 powernow_table
= kzalloc((sizeof(*powernow_table
) *
349 (number_scales
+ 1)), GFP_KERNEL
);
350 if (!powernow_table
) {
355 pc
.val
= (unsigned long) acpi_processor_perf
->states
[0].control
;
356 for (i
= 0; i
< number_scales
; i
++) {
358 struct acpi_processor_px
*state
=
359 &acpi_processor_perf
->states
[i
];
360 unsigned int speed
, speed_mhz
;
362 pc
.val
= (unsigned long) state
->control
;
363 pr_debug("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
365 (u32
) state
->core_frequency
,
367 (u32
) state
->transition_latency
,
368 (u32
) state
->control
,
374 powernow_table
[i
].frequency
= fsb
* fid_codes
[fid
] / 10;
375 powernow_table
[i
].driver_data
= fid
; /* lower 8 bits */
376 powernow_table
[i
].driver_data
|= (vid
<< 8); /* upper 8 bits */
378 speed
= powernow_table
[i
].frequency
;
379 speed_mhz
= speed
/ 1000;
381 /* processor_perflib will multiply the MHz value by 1000 to
382 * get a KHz value (e.g. 1266000). However, powernow-k7 works
383 * with true KHz values (e.g. 1266768). To ensure that all
384 * powernow frequencies are available, we must ensure that
385 * ACPI doesn't restrict them, so we round up the MHz value
386 * to ensure that perflib's computed KHz value is greater than
387 * or equal to powernow's KHz value.
389 if (speed
% 1000 > 0)
392 if ((fid_codes
[fid
] % 10) == 5) {
397 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
398 "VID: 0x%x (%d.%03dV)\n", fid
, fid_codes
[fid
] / 10,
399 fid_codes
[fid
] % 10, speed_mhz
, vid
,
400 mobile_vid_table
[vid
]/1000,
401 mobile_vid_table
[vid
]%1000);
403 if (state
->core_frequency
!= speed_mhz
) {
404 state
->core_frequency
= speed_mhz
;
405 pr_debug(" Corrected ACPI frequency to %d\n",
409 if (latency
< pc
.bits
.sgtc
)
410 latency
= pc
.bits
.sgtc
;
412 if (speed
< minimum_speed
)
413 minimum_speed
= speed
;
414 if (speed
> maximum_speed
)
415 maximum_speed
= speed
;
418 powernow_table
[i
].frequency
= CPUFREQ_TABLE_END
;
419 powernow_table
[i
].driver_data
= 0;
421 /* notify BIOS that we exist */
422 acpi_processor_notify_smm(THIS_MODULE
);
427 acpi_processor_unregister_performance(acpi_processor_perf
, 0);
429 free_cpumask_var(acpi_processor_perf
->shared_cpu_map
);
431 kfree(acpi_processor_perf
);
433 printk(KERN_WARNING PFX
"ACPI perflib can not be used on "
435 acpi_processor_perf
= NULL
;
439 static int powernow_acpi_init(void)
441 printk(KERN_INFO PFX
"no support for ACPI processor found."
442 " Please recompile your kernel with ACPI processor\n");
447 static void print_pst_entry(struct pst_s
*pst
, unsigned int j
)
449 pr_debug("PST:%d (@%p)\n", j
, pst
);
450 pr_debug(" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
451 pst
->cpuid
, pst
->fsbspeed
, pst
->maxfid
, pst
->startvid
);
454 static int powernow_decode_bios(int maxfid
, int startvid
)
463 etuple
= cpuid_eax(0x80000001);
465 for (i
= 0xC0000; i
< 0xffff0 ; i
+= 16) {
469 if (memcmp(p
, "AMDK7PNOW!", 10) == 0) {
470 pr_debug("Found PSB header at %p\n", p
);
471 psb
= (struct psb_s
*) p
;
472 pr_debug("Table version: 0x%x\n", psb
->tableversion
);
473 if (psb
->tableversion
!= 0x12) {
474 printk(KERN_INFO PFX
"Sorry, only v1.2 tables"
475 " supported right now\n");
479 pr_debug("Flags: 0x%x\n", psb
->flags
);
480 if ((psb
->flags
& 1) == 0)
481 pr_debug("Mobile voltage regulator\n");
483 pr_debug("Desktop voltage regulator\n");
485 latency
= psb
->settlingtime
;
487 printk(KERN_INFO PFX
"BIOS set settling time "
488 "to %d microseconds. "
489 "Should be at least 100. "
490 "Correcting.\n", latency
);
493 pr_debug("Settling Time: %d microseconds.\n",
495 pr_debug("Has %d PST tables. (Only dumping ones "
496 "relevant to this CPU).\n",
501 pst
= (struct pst_s
*) p
;
503 for (j
= 0; j
< psb
->numpst
; j
++) {
504 pst
= (struct pst_s
*) p
;
505 number_scales
= pst
->numpstates
;
507 if ((etuple
== pst
->cpuid
) &&
508 check_fsb(pst
->fsbspeed
) &&
509 (maxfid
== pst
->maxfid
) &&
510 (startvid
== pst
->startvid
)) {
511 print_pst_entry(pst
, j
);
512 p
= (char *)pst
+ sizeof(*pst
);
517 p
= (char *)pst
+ sizeof(*pst
);
518 for (k
= 0; k
< number_scales
; k
++)
522 printk(KERN_INFO PFX
"No PST tables match this cpuid "
524 printk(KERN_INFO PFX
"This is indicative of a broken "
536 static int powernow_target(struct cpufreq_policy
*policy
,
537 unsigned int target_freq
,
538 unsigned int relation
)
540 unsigned int newstate
;
542 if (cpufreq_frequency_table_target(policy
, powernow_table
, target_freq
,
543 relation
, &newstate
))
546 change_speed(policy
, newstate
);
552 static int powernow_verify(struct cpufreq_policy
*policy
)
554 return cpufreq_frequency_table_verify(policy
, powernow_table
);
558 * We use the fact that the bus frequency is somehow
559 * a multiple of 100000/3 khz, then we compute sgtc according
561 * That way, we match more how AMD thinks all of that work.
562 * We will then get the same kind of behaviour already tested under
563 * the "well-known" other OS.
565 static int fixup_sgtc(void)
576 sgtc
= 100 * m
* latency
;
578 if (sgtc
> 0xfffff) {
579 printk(KERN_WARNING PFX
"SGTC too large %d\n", sgtc
);
585 static unsigned int powernow_get(unsigned int cpu
)
587 union msr_fidvidstatus fidvidstatus
;
592 rdmsrl(MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
593 cfid
= fidvidstatus
.bits
.CFID
;
595 return fsb
* fid_codes
[cfid
] / 10;
599 static int acer_cpufreq_pst(const struct dmi_system_id
*d
)
601 printk(KERN_WARNING PFX
602 "%s laptop with broken PST tables in BIOS detected.\n",
604 printk(KERN_WARNING PFX
605 "You need to downgrade to 3A21 (09/09/2002), or try a newer "
606 "BIOS than 3A71 (01/20/2003)\n");
607 printk(KERN_WARNING PFX
608 "cpufreq scaling has been disabled as a result of this.\n");
613 * Some Athlon laptops have really fucked PST tables.
614 * A BIOS update is all that can save them.
615 * Mention this, and disable cpufreq.
617 static struct dmi_system_id powernow_dmi_table
[] = {
619 .callback
= acer_cpufreq_pst
,
620 .ident
= "Acer Aspire",
622 DMI_MATCH(DMI_SYS_VENDOR
, "Insyde Software"),
623 DMI_MATCH(DMI_BIOS_VERSION
, "3A71"),
629 static int powernow_cpu_init(struct cpufreq_policy
*policy
)
631 union msr_fidvidstatus fidvidstatus
;
634 if (policy
->cpu
!= 0)
637 rdmsrl(MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
639 recalibrate_cpu_khz();
641 fsb
= (10 * cpu_khz
) / fid_codes
[fidvidstatus
.bits
.CFID
];
643 printk(KERN_WARNING PFX
"can not determine bus frequency\n");
646 pr_debug("FSB: %3dMHz\n", fsb
/1000);
648 if (dmi_check_system(powernow_dmi_table
) || acpi_force
) {
649 printk(KERN_INFO PFX
"PSB/PST known to be broken. "
650 "Trying ACPI instead\n");
651 result
= powernow_acpi_init();
653 result
= powernow_decode_bios(fidvidstatus
.bits
.MFID
,
654 fidvidstatus
.bits
.SVID
);
656 printk(KERN_INFO PFX
"Trying ACPI perflib\n");
660 result
= powernow_acpi_init();
663 "ACPI and legacy methods failed\n");
666 /* SGTC use the bus clock as timer */
667 latency
= fixup_sgtc();
668 printk(KERN_INFO PFX
"SGTC: %d\n", latency
);
675 printk(KERN_INFO PFX
"Minimum speed %d MHz. Maximum speed %d MHz.\n",
676 minimum_speed
/1000, maximum_speed
/1000);
678 policy
->cpuinfo
.transition_latency
=
679 cpufreq_scale(2000000UL, fsb
, latency
);
681 policy
->cur
= powernow_get(0);
683 cpufreq_frequency_table_get_attr(powernow_table
, policy
->cpu
);
685 return cpufreq_frequency_table_cpuinfo(policy
, powernow_table
);
688 static int powernow_cpu_exit(struct cpufreq_policy
*policy
)
690 cpufreq_frequency_table_put_attr(policy
->cpu
);
692 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
693 if (acpi_processor_perf
) {
694 acpi_processor_unregister_performance(acpi_processor_perf
, 0);
695 free_cpumask_var(acpi_processor_perf
->shared_cpu_map
);
696 kfree(acpi_processor_perf
);
700 kfree(powernow_table
);
704 static struct freq_attr
*powernow_table_attr
[] = {
705 &cpufreq_freq_attr_scaling_available_freqs
,
709 static struct cpufreq_driver powernow_driver
= {
710 .verify
= powernow_verify
,
711 .target
= powernow_target
,
713 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
714 .bios_limit
= acpi_processor_get_bios_limit
,
716 .init
= powernow_cpu_init
,
717 .exit
= powernow_cpu_exit
,
718 .name
= "powernow-k7",
719 .attr
= powernow_table_attr
,
722 static int __init
powernow_init(void)
724 if (check_powernow() == 0)
726 return cpufreq_register_driver(&powernow_driver
);
730 static void __exit
powernow_exit(void)
732 cpufreq_unregister_driver(&powernow_driver
);
735 module_param(acpi_force
, int, 0444);
736 MODULE_PARM_DESC(acpi_force
, "Force ACPI to be used.");
738 MODULE_AUTHOR("Dave Jones <davej@redhat.com>");
739 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
740 MODULE_LICENSE("GPL");
742 late_initcall(powernow_init
);
743 module_exit(powernow_exit
);