2 * AMD K7 Powernow driver.
3 * (C) 2003 Dave Jones on behalf of SuSE Labs.
5 * Licensed under the terms of the GNU GPL License version 2.
6 * Based upon datasheets & sample CPUs kindly provided by AMD.
9 * CPU 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.
12 * CPU with half frequency multipliers may hang upon wakeup from disconnect.
13 * - We disable half multipliers if ACPI is used on A0 stepping CPUs.
16 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/moduleparam.h>
21 #include <linux/init.h>
22 #include <linux/cpufreq.h>
23 #include <linux/slab.h>
24 #include <linux/string.h>
25 #include <linux/dmi.h>
26 #include <linux/timex.h>
29 #include <asm/timer.h> /* Needed for recalibrate_cpu_khz() */
31 #include <asm/cpu_device_id.h>
33 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
34 #include <linux/acpi.h>
35 #include <acpi/processor.h>
38 #include "powernow-k7.h"
57 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
58 union powernow_acpi_control_t
{
69 /* divide by 1000 to get VCore voltage in V. */
70 static const int mobile_vid_table
[32] = {
71 2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650,
72 1600, 1550, 1500, 1450, 1400, 1350, 1300, 0,
73 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100,
74 1075, 1050, 1025, 1000, 975, 950, 925, 0,
77 /* divide by 10 to get FID. */
78 static const int fid_codes
[32] = {
79 110, 115, 120, 125, 50, 55, 60, 65,
80 70, 75, 80, 85, 90, 95, 100, 105,
81 30, 190, 40, 200, 130, 135, 140, 210,
82 150, 225, 160, 165, 170, 180, -1, -1,
85 /* This parameter is used in order to force ACPI instead of legacy method for
86 * configuration purpose.
89 static int acpi_force
;
91 static struct cpufreq_frequency_table
*powernow_table
;
93 static unsigned int can_scale_bus
;
94 static unsigned int can_scale_vid
;
95 static unsigned int minimum_speed
= -1;
96 static unsigned int maximum_speed
;
97 static unsigned int number_scales
;
98 static unsigned int fsb
;
99 static unsigned int latency
;
102 static int check_fsb(unsigned int fsbspeed
)
105 unsigned int f
= fsb
/ 1000;
107 delta
= (fsbspeed
> f
) ? fsbspeed
- f
: f
- fsbspeed
;
111 static const struct x86_cpu_id powernow_k7_cpuids
[] = {
112 { X86_VENDOR_AMD
, 6, },
115 MODULE_DEVICE_TABLE(x86cpu
, powernow_k7_cpuids
);
117 static int check_powernow(void)
119 struct cpuinfo_x86
*c
= &cpu_data(0);
120 unsigned int maxei
, eax
, ebx
, ecx
, edx
;
122 if (!x86_match_cpu(powernow_k7_cpuids
))
125 /* Get maximum capabilities */
126 maxei
= cpuid_eax(0x80000000);
127 if (maxei
< 0x80000007) { /* Any powernow info ? */
129 pr_info("No powernow capabilities detected\n");
134 if ((c
->x86_model
== 6) && (c
->x86_mask
== 0)) {
135 pr_info("K7 660[A0] core detected, enabling errata workarounds\n");
139 cpuid(0x80000007, &eax
, &ebx
, &ecx
, &edx
);
141 /* Check we can actually do something before we say anything.*/
142 if (!(edx
& (1 << 1 | 1 << 2)))
145 pr_info("PowerNOW! Technology present. Can scale: ");
148 pr_cont("frequency");
152 if ((edx
& (1 << 1 | 1 << 2)) == 0x6)
164 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
165 static void invalidate_entry(unsigned int entry
)
167 powernow_table
[entry
].frequency
= CPUFREQ_ENTRY_INVALID
;
171 static int get_ranges(unsigned char *pst
)
177 powernow_table
= kzalloc((sizeof(*powernow_table
) *
178 (number_scales
+ 1)), GFP_KERNEL
);
182 for (j
= 0 ; j
< number_scales
; j
++) {
185 powernow_table
[j
].frequency
= (fsb
* fid_codes
[fid
]) / 10;
186 powernow_table
[j
].driver_data
= fid
; /* lower 8 bits */
188 speed
= powernow_table
[j
].frequency
;
190 if ((fid_codes
[fid
] % 10) == 5) {
191 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
197 if (speed
< minimum_speed
)
198 minimum_speed
= speed
;
199 if (speed
> maximum_speed
)
200 maximum_speed
= speed
;
203 powernow_table
[j
].driver_data
|= (vid
<< 8); /* upper 8 bits */
205 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
206 "VID: 0x%x (%d.%03dV)\n", fid
, fid_codes
[fid
] / 10,
207 fid_codes
[fid
] % 10, speed
/1000, vid
,
208 mobile_vid_table
[vid
]/1000,
209 mobile_vid_table
[vid
]%1000);
211 powernow_table
[number_scales
].frequency
= CPUFREQ_TABLE_END
;
212 powernow_table
[number_scales
].driver_data
= 0;
218 static void change_FID(int fid
)
220 union msr_fidvidctl fidvidctl
;
222 rdmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
223 if (fidvidctl
.bits
.FID
!= fid
) {
224 fidvidctl
.bits
.SGTC
= latency
;
225 fidvidctl
.bits
.FID
= fid
;
226 fidvidctl
.bits
.VIDC
= 0;
227 fidvidctl
.bits
.FIDC
= 1;
228 wrmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
233 static void change_VID(int vid
)
235 union msr_fidvidctl fidvidctl
;
237 rdmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
238 if (fidvidctl
.bits
.VID
!= vid
) {
239 fidvidctl
.bits
.SGTC
= latency
;
240 fidvidctl
.bits
.VID
= vid
;
241 fidvidctl
.bits
.FIDC
= 0;
242 fidvidctl
.bits
.VIDC
= 1;
243 wrmsrl(MSR_K7_FID_VID_CTL
, fidvidctl
.val
);
248 static int powernow_target(struct cpufreq_policy
*policy
, unsigned int index
)
251 struct cpufreq_freqs freqs
;
252 union msr_fidvidstatus fidvidstatus
;
255 /* fid are the lower 8 bits of the index we stored into
256 * the cpufreq frequency table in powernow_decode_bios,
257 * vid are the upper 8 bits.
260 fid
= powernow_table
[index
].driver_data
& 0xFF;
261 vid
= (powernow_table
[index
].driver_data
& 0xFF00) >> 8;
263 rdmsrl(MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
264 cfid
= fidvidstatus
.bits
.CFID
;
265 freqs
.old
= fsb
* fid_codes
[cfid
] / 10;
267 freqs
.new = powernow_table
[index
].frequency
;
269 /* Now do the magic poking into the MSRs. */
271 if (have_a0
== 1) /* A0 errata 5 */
274 if (freqs
.old
> freqs
.new) {
275 /* Going down, so change FID first */
279 /* Going up, so change VID first */
292 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
294 static struct acpi_processor_performance
*acpi_processor_perf
;
296 static int powernow_acpi_init(void)
300 union powernow_acpi_control_t pc
;
302 if (acpi_processor_perf
!= NULL
&& powernow_table
!= NULL
) {
307 acpi_processor_perf
= kzalloc(sizeof(*acpi_processor_perf
), GFP_KERNEL
);
308 if (!acpi_processor_perf
) {
313 if (!zalloc_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
!=
325 ACPI_ADR_SPACE_FIXED_HARDWARE
) {
330 if (acpi_processor_perf
->status_register
.space_id
!=
331 ACPI_ADR_SPACE_FIXED_HARDWARE
) {
336 number_scales
= acpi_processor_perf
->state_count
;
338 if (number_scales
< 2) {
343 powernow_table
= kzalloc((sizeof(*powernow_table
) *
344 (number_scales
+ 1)), GFP_KERNEL
);
345 if (!powernow_table
) {
350 pc
.val
= (unsigned long) acpi_processor_perf
->states
[0].control
;
351 for (i
= 0; i
< number_scales
; i
++) {
353 struct acpi_processor_px
*state
=
354 &acpi_processor_perf
->states
[i
];
355 unsigned int speed
, speed_mhz
;
357 pc
.val
= (unsigned long) state
->control
;
358 pr_debug("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n",
360 (u32
) state
->core_frequency
,
362 (u32
) state
->transition_latency
,
363 (u32
) state
->control
,
369 powernow_table
[i
].frequency
= fsb
* fid_codes
[fid
] / 10;
370 powernow_table
[i
].driver_data
= fid
; /* lower 8 bits */
371 powernow_table
[i
].driver_data
|= (vid
<< 8); /* upper 8 bits */
373 speed
= powernow_table
[i
].frequency
;
374 speed_mhz
= speed
/ 1000;
376 /* processor_perflib will multiply the MHz value by 1000 to
377 * get a KHz value (e.g. 1266000). However, powernow-k7 works
378 * with true KHz values (e.g. 1266768). To ensure that all
379 * powernow frequencies are available, we must ensure that
380 * ACPI doesn't restrict them, so we round up the MHz value
381 * to ensure that perflib's computed KHz value is greater than
382 * or equal to powernow's KHz value.
384 if (speed
% 1000 > 0)
387 if ((fid_codes
[fid
] % 10) == 5) {
392 pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) "
393 "VID: 0x%x (%d.%03dV)\n", fid
, fid_codes
[fid
] / 10,
394 fid_codes
[fid
] % 10, speed_mhz
, vid
,
395 mobile_vid_table
[vid
]/1000,
396 mobile_vid_table
[vid
]%1000);
398 if (state
->core_frequency
!= speed_mhz
) {
399 state
->core_frequency
= speed_mhz
;
400 pr_debug(" Corrected ACPI frequency to %d\n",
404 if (latency
< pc
.bits
.sgtc
)
405 latency
= pc
.bits
.sgtc
;
407 if (speed
< minimum_speed
)
408 minimum_speed
= speed
;
409 if (speed
> maximum_speed
)
410 maximum_speed
= speed
;
413 powernow_table
[i
].frequency
= CPUFREQ_TABLE_END
;
414 powernow_table
[i
].driver_data
= 0;
416 /* notify BIOS that we exist */
417 acpi_processor_notify_smm(THIS_MODULE
);
422 acpi_processor_unregister_performance(0);
424 free_cpumask_var(acpi_processor_perf
->shared_cpu_map
);
426 kfree(acpi_processor_perf
);
428 pr_warn("ACPI perflib can not be used on this platform\n");
429 acpi_processor_perf
= NULL
;
433 static int powernow_acpi_init(void)
435 pr_info("no support for ACPI processor found - please recompile your kernel with ACPI processor\n");
440 static void print_pst_entry(struct pst_s
*pst
, unsigned int j
)
442 pr_debug("PST:%d (@%p)\n", j
, pst
);
443 pr_debug(" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n",
444 pst
->cpuid
, pst
->fsbspeed
, pst
->maxfid
, pst
->startvid
);
447 static int powernow_decode_bios(int maxfid
, int startvid
)
456 etuple
= cpuid_eax(0x80000001);
458 for (i
= 0xC0000; i
< 0xffff0 ; i
+= 16) {
462 if (memcmp(p
, "AMDK7PNOW!", 10) == 0) {
463 pr_debug("Found PSB header at %p\n", p
);
464 psb
= (struct psb_s
*) p
;
465 pr_debug("Table version: 0x%x\n", psb
->tableversion
);
466 if (psb
->tableversion
!= 0x12) {
467 pr_info("Sorry, only v1.2 tables supported right now\n");
471 pr_debug("Flags: 0x%x\n", psb
->flags
);
472 if ((psb
->flags
& 1) == 0)
473 pr_debug("Mobile voltage regulator\n");
475 pr_debug("Desktop voltage regulator\n");
477 latency
= psb
->settlingtime
;
479 pr_info("BIOS set settling time to %d microseconds. Should be at least 100. Correcting.\n",
483 pr_debug("Settling Time: %d microseconds.\n",
485 pr_debug("Has %d PST tables. (Only dumping ones "
486 "relevant to this CPU).\n",
491 pst
= (struct pst_s
*) p
;
493 for (j
= 0; j
< psb
->numpst
; j
++) {
494 pst
= (struct pst_s
*) p
;
495 number_scales
= pst
->numpstates
;
497 if ((etuple
== pst
->cpuid
) &&
498 check_fsb(pst
->fsbspeed
) &&
499 (maxfid
== pst
->maxfid
) &&
500 (startvid
== pst
->startvid
)) {
501 print_pst_entry(pst
, j
);
502 p
= (char *)pst
+ sizeof(*pst
);
507 p
= (char *)pst
+ sizeof(*pst
);
508 for (k
= 0; k
< number_scales
; k
++)
512 pr_info("No PST tables match this cpuid (0x%x)\n",
514 pr_info("This is indicative of a broken BIOS\n");
526 * We use the fact that the bus frequency is somehow
527 * a multiple of 100000/3 khz, then we compute sgtc according
529 * That way, we match more how AMD thinks all of that work.
530 * We will then get the same kind of behaviour already tested under
531 * the "well-known" other OS.
533 static int fixup_sgtc(void)
544 sgtc
= 100 * m
* latency
;
546 if (sgtc
> 0xfffff) {
547 pr_warn("SGTC too large %d\n", sgtc
);
553 static unsigned int powernow_get(unsigned int cpu
)
555 union msr_fidvidstatus fidvidstatus
;
560 rdmsrl(MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
561 cfid
= fidvidstatus
.bits
.CFID
;
563 return fsb
* fid_codes
[cfid
] / 10;
567 static int acer_cpufreq_pst(const struct dmi_system_id
*d
)
569 pr_warn("%s laptop with broken PST tables in BIOS detected\n",
571 pr_warn("You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n");
572 pr_warn("cpufreq scaling has been disabled as a result of this\n");
577 * Some Athlon laptops have really fucked PST tables.
578 * A BIOS update is all that can save them.
579 * Mention this, and disable cpufreq.
581 static struct dmi_system_id powernow_dmi_table
[] = {
583 .callback
= acer_cpufreq_pst
,
584 .ident
= "Acer Aspire",
586 DMI_MATCH(DMI_SYS_VENDOR
, "Insyde Software"),
587 DMI_MATCH(DMI_BIOS_VERSION
, "3A71"),
593 static int powernow_cpu_init(struct cpufreq_policy
*policy
)
595 union msr_fidvidstatus fidvidstatus
;
598 if (policy
->cpu
!= 0)
601 rdmsrl(MSR_K7_FID_VID_STATUS
, fidvidstatus
.val
);
603 recalibrate_cpu_khz();
605 fsb
= (10 * cpu_khz
) / fid_codes
[fidvidstatus
.bits
.CFID
];
607 pr_warn("can not determine bus frequency\n");
610 pr_debug("FSB: %3dMHz\n", fsb
/1000);
612 if (dmi_check_system(powernow_dmi_table
) || acpi_force
) {
613 pr_info("PSB/PST known to be broken - trying ACPI instead\n");
614 result
= powernow_acpi_init();
616 result
= powernow_decode_bios(fidvidstatus
.bits
.MFID
,
617 fidvidstatus
.bits
.SVID
);
619 pr_info("Trying ACPI perflib\n");
623 result
= powernow_acpi_init();
625 pr_info("ACPI and legacy methods failed\n");
628 /* SGTC use the bus clock as timer */
629 latency
= fixup_sgtc();
630 pr_info("SGTC: %d\n", latency
);
637 pr_info("Minimum speed %d MHz - Maximum speed %d MHz\n",
638 minimum_speed
/1000, maximum_speed
/1000);
640 policy
->cpuinfo
.transition_latency
=
641 cpufreq_scale(2000000UL, fsb
, latency
);
643 return cpufreq_table_validate_and_show(policy
, powernow_table
);
646 static int powernow_cpu_exit(struct cpufreq_policy
*policy
)
648 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
649 if (acpi_processor_perf
) {
650 acpi_processor_unregister_performance(0);
651 free_cpumask_var(acpi_processor_perf
->shared_cpu_map
);
652 kfree(acpi_processor_perf
);
656 kfree(powernow_table
);
660 static struct cpufreq_driver powernow_driver
= {
661 .verify
= cpufreq_generic_frequency_table_verify
,
662 .target_index
= powernow_target
,
664 #ifdef CONFIG_X86_POWERNOW_K7_ACPI
665 .bios_limit
= acpi_processor_get_bios_limit
,
667 .init
= powernow_cpu_init
,
668 .exit
= powernow_cpu_exit
,
669 .name
= "powernow-k7",
670 .attr
= cpufreq_generic_attr
,
673 static int __init
powernow_init(void)
675 if (check_powernow() == 0)
677 return cpufreq_register_driver(&powernow_driver
);
681 static void __exit
powernow_exit(void)
683 cpufreq_unregister_driver(&powernow_driver
);
686 module_param(acpi_force
, int, 0444);
687 MODULE_PARM_DESC(acpi_force
, "Force ACPI to be used.");
689 MODULE_AUTHOR("Dave Jones");
690 MODULE_DESCRIPTION("Powernow driver for AMD K7 processors.");
691 MODULE_LICENSE("GPL");
693 late_initcall(powernow_init
);
694 module_exit(powernow_exit
);