diff options
Diffstat (limited to 'arch/i386/kernel/cpu/cpufreq/powernow-k7.c')
| -rw-r--r-- | arch/i386/kernel/cpu/cpufreq/powernow-k7.c | 690 |
1 files changed, 690 insertions, 0 deletions
diff --git a/arch/i386/kernel/cpu/cpufreq/powernow-k7.c b/arch/i386/kernel/cpu/cpufreq/powernow-k7.c new file mode 100644 index 000000000000..913f652623d9 --- /dev/null +++ b/arch/i386/kernel/cpu/cpufreq/powernow-k7.c @@ -0,0 +1,690 @@ +/* + * AMD K7 Powernow driver. + * (C) 2003 Dave Jones <davej@codemonkey.org.uk> on behalf of SuSE Labs. + * (C) 2003-2004 Dave Jones <davej@redhat.com> + * + * Licensed under the terms of the GNU GPL License version 2. + * Based upon datasheets & sample CPUs kindly provided by AMD. + * + * Errata 5: Processor may fail to execute a FID/VID change in presence of interrupt. + * - We cli/sti on stepping A0 CPUs around the FID/VID transition. + * Errata 15: Processors with half frequency multipliers may hang upon wakeup from disconnect. + * - We disable half multipliers if ACPI is used on A0 stepping CPUs. + */ + +#include <linux/config.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/init.h> +#include <linux/cpufreq.h> +#include <linux/slab.h> +#include <linux/string.h> +#include <linux/dmi.h> + +#include <asm/msr.h> +#include <asm/timex.h> +#include <asm/io.h> +#include <asm/system.h> + +#ifdef CONFIG_X86_POWERNOW_K7_ACPI +#include <linux/acpi.h> +#include <acpi/processor.h> +#endif + +#include "powernow-k7.h" + +#define PFX "powernow: " + + +struct psb_s { + u8 signature[10]; + u8 tableversion; + u8 flags; + u16 settlingtime; + u8 reserved1; + u8 numpst; +}; + +struct pst_s { + u32 cpuid; + u8 fsbspeed; + u8 maxfid; + u8 startvid; + u8 numpstates; +}; + +#ifdef CONFIG_X86_POWERNOW_K7_ACPI +union powernow_acpi_control_t { + struct { + unsigned long fid:5, + vid:5, + sgtc:20, + res1:2; + } bits; + unsigned long val; +}; +#endif + +#ifdef CONFIG_CPU_FREQ_DEBUG +/* divide by 1000 to get VCore voltage in V. */ +static int mobile_vid_table[32] = { + 2000, 1950, 1900, 1850, 1800, 1750, 1700, 1650, + 1600, 1550, 1500, 1450, 1400, 1350, 1300, 0, + 1275, 1250, 1225, 1200, 1175, 1150, 1125, 1100, + 1075, 1050, 1025, 1000, 975, 950, 925, 0, +}; +#endif + +/* divide by 10 to get FID. */ +static int fid_codes[32] = { + 110, 115, 120, 125, 50, 55, 60, 65, + 70, 75, 80, 85, 90, 95, 100, 105, + 30, 190, 40, 200, 130, 135, 140, 210, + 150, 225, 160, 165, 170, 180, -1, -1, +}; + +/* This parameter is used in order to force ACPI instead of legacy method for + * configuration purpose. + */ + +static int acpi_force; + +static struct cpufreq_frequency_table *powernow_table; + +static unsigned int can_scale_bus; +static unsigned int can_scale_vid; +static unsigned int minimum_speed=-1; +static unsigned int maximum_speed; +static unsigned int number_scales; +static unsigned int fsb; +static unsigned int latency; +static char have_a0; + +#define dprintk(msg...) cpufreq_debug_printk(CPUFREQ_DEBUG_DRIVER, "powernow-k7", msg) + +static int check_fsb(unsigned int fsbspeed) +{ + int delta; + unsigned int f = fsb / 1000; + + delta = (fsbspeed > f) ? fsbspeed - f : f - fsbspeed; + return (delta < 5); +} + +static int check_powernow(void) +{ + struct cpuinfo_x86 *c = cpu_data; + unsigned int maxei, eax, ebx, ecx, edx; + + if ((c->x86_vendor != X86_VENDOR_AMD) || (c->x86 !=6)) { +#ifdef MODULE + printk (KERN_INFO PFX "This module only works with AMD K7 CPUs\n"); +#endif + return 0; + } + + /* Get maximum capabilities */ + maxei = cpuid_eax (0x80000000); + if (maxei < 0x80000007) { /* Any powernow info ? */ +#ifdef MODULE + printk (KERN_INFO PFX "No powernow capabilities detected\n"); +#endif + return 0; + } + + if ((c->x86_model == 6) && (c->x86_mask == 0)) { + printk (KERN_INFO PFX "K7 660[A0] core detected, enabling errata workarounds\n"); + have_a0 = 1; + } + + cpuid(0x80000007, &eax, &ebx, &ecx, &edx); + + /* Check we can actually do something before we say anything.*/ + if (!(edx & (1 << 1 | 1 << 2))) + return 0; + + printk (KERN_INFO PFX "PowerNOW! Technology present. Can scale: "); + + if (edx & 1 << 1) { + printk ("frequency"); + can_scale_bus=1; + } + + if ((edx & (1 << 1 | 1 << 2)) == 0x6) + printk (" and "); + + if (edx & 1 << 2) { + printk ("voltage"); + can_scale_vid=1; + } + + printk (".\n"); + return 1; +} + + +static int get_ranges (unsigned char *pst) +{ + unsigned int j; + unsigned int speed; + u8 fid, vid; + + powernow_table = kmalloc((sizeof(struct cpufreq_frequency_table) * (number_scales + 1)), GFP_KERNEL); + if (!powernow_table) + return -ENOMEM; + memset(powernow_table, 0, (sizeof(struct cpufreq_frequency_table) * (number_scales + 1))); + + for (j=0 ; j < number_scales; j++) { + fid = *pst++; + + powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10; + powernow_table[j].index = fid; /* lower 8 bits */ + + speed = powernow_table[j].frequency; + + if ((fid_codes[fid] % 10)==5) { +#ifdef CONFIG_X86_POWERNOW_K7_ACPI + if (have_a0 == 1) + powernow_table[j].frequency = CPUFREQ_ENTRY_INVALID; +#endif + } + + if (speed < minimum_speed) + minimum_speed = speed; + if (speed > maximum_speed) + maximum_speed = speed; + + vid = *pst++; + powernow_table[j].index |= (vid << 8); /* upper 8 bits */ + + dprintk (" FID: 0x%x (%d.%dx [%dMHz]) " + "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10, + fid_codes[fid] % 10, speed/1000, vid, + mobile_vid_table[vid]/1000, + mobile_vid_table[vid]%1000); + } + powernow_table[number_scales].frequency = CPUFREQ_TABLE_END; + powernow_table[number_scales].index = 0; + + return 0; +} + + +static void change_FID(int fid) +{ + union msr_fidvidctl fidvidctl; + + rdmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val); + if (fidvidctl.bits.FID != fid) { + fidvidctl.bits.SGTC = latency; + fidvidctl.bits.FID = fid; + fidvidctl.bits.VIDC = 0; + fidvidctl.bits.FIDC = 1; + wrmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val); + } +} + + +static void change_VID(int vid) +{ + union msr_fidvidctl fidvidctl; + + rdmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val); + if (fidvidctl.bits.VID != vid) { + fidvidctl.bits.SGTC = latency; + fidvidctl.bits.VID = vid; + fidvidctl.bits.FIDC = 0; + fidvidctl.bits.VIDC = 1; + wrmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val); + } +} + + +static void change_speed (unsigned int index) +{ + u8 fid, vid; + struct cpufreq_freqs freqs; + union msr_fidvidstatus fidvidstatus; + int cfid; + + /* fid are the lower 8 bits of the index we stored into + * the cpufreq frequency table in powernow_decode_bios, + * vid are the upper 8 bits. + */ + + fid = powernow_table[index].index & 0xFF; + vid = (powernow_table[index].index & 0xFF00) >> 8; + + freqs.cpu = 0; + + rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val); + cfid = fidvidstatus.bits.CFID; + freqs.old = fsb * fid_codes[cfid] / 10; + + freqs.new = powernow_table[index].frequency; + + cpufreq_notify_transition(&freqs, CPUFREQ_PRECHANGE); + + /* Now do the magic poking into the MSRs. */ + + if (have_a0 == 1) /* A0 errata 5 */ + local_irq_disable(); + + if (freqs.old > freqs.new) { + /* Going down, so change FID first */ + change_FID(fid); + change_VID(vid); + } else { + /* Going up, so change VID first */ + change_VID(vid); + change_FID(fid); + } + + + if (have_a0 == 1) + local_irq_enable(); + + cpufreq_notify_transition(&freqs, CPUFREQ_POSTCHANGE); +} + + +#ifdef CONFIG_X86_POWERNOW_K7_ACPI + +static struct acpi_processor_performance *acpi_processor_perf; + +static int powernow_acpi_init(void) +{ + int i; + int retval = 0; + union powernow_acpi_control_t pc; + + if (acpi_processor_perf != NULL && powernow_table != NULL) { + retval = -EINVAL; + goto err0; + } + + acpi_processor_perf = kmalloc(sizeof(struct acpi_processor_performance), + GFP_KERNEL); + + if (!acpi_processor_perf) { + retval = -ENOMEM; + goto err0; + } + + memset(acpi_processor_perf, 0, sizeof(struct acpi_processor_performance)); + + if (acpi_processor_register_performance(acpi_processor_perf, 0)) { + retval = -EIO; + goto err1; + } + + if (acpi_processor_perf->control_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) { + retval = -ENODEV; + goto err2; + } + + if (acpi_processor_perf->status_register.space_id != ACPI_ADR_SPACE_FIXED_HARDWARE) { + retval = -ENODEV; + goto err2; + } + + number_scales = acpi_processor_perf->state_count; + + if (number_scales < 2) { + retval = -ENODEV; + goto err2; + } + + powernow_table = kmalloc((number_scales + 1) * (sizeof(struct cpufreq_frequency_table)), GFP_KERNEL); + if (!powernow_table) { + retval = -ENOMEM; + goto err2; + } + + memset(powernow_table, 0, ((number_scales + 1) * sizeof(struct cpufreq_frequency_table))); + + pc.val = (unsigned long) acpi_processor_perf->states[0].control; + for (i = 0; i < number_scales; i++) { + u8 fid, vid; + unsigned int speed; + + pc.val = (unsigned long) acpi_processor_perf->states[i].control; + dprintk ("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n", + i, + (u32) acpi_processor_perf->states[i].core_frequency, + (u32) acpi_processor_perf->states[i].power, + (u32) acpi_processor_perf->states[i].transition_latency, + (u32) acpi_processor_perf->states[i].control, + pc.bits.sgtc); + + vid = pc.bits.vid; + fid = pc.bits.fid; + + powernow_table[i].frequency = fsb * fid_codes[fid] / 10; + powernow_table[i].index = fid; /* lower 8 bits */ + powernow_table[i].index |= (vid << 8); /* upper 8 bits */ + + speed = powernow_table[i].frequency; + + if ((fid_codes[fid] % 10)==5) { + if (have_a0 == 1) + powernow_table[i].frequency = CPUFREQ_ENTRY_INVALID; + } + + dprintk (" FID: 0x%x (%d.%dx [%dMHz]) " + "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10, + fid_codes[fid] % 10, speed/1000, vid, + mobile_vid_table[vid]/1000, + mobile_vid_table[vid]%1000); + + if (latency < pc.bits.sgtc) + latency = pc.bits.sgtc; + + if (speed < minimum_speed) + minimum_speed = speed; + if (speed > maximum_speed) + maximum_speed = speed; + } + + powernow_table[i].frequency = CPUFREQ_TABLE_END; + powernow_table[i].index = 0; + + /* notify BIOS that we exist */ + acpi_processor_notify_smm(THIS_MODULE); + + return 0; + +err2: + acpi_processor_unregister_performance(acpi_processor_perf, 0); +err1: + kfree(acpi_processor_perf); +err0: + printk(KERN_WARNING PFX "ACPI perflib can not be used in this platform\n"); + acpi_processor_perf = NULL; + return retval; +} +#else +static int powernow_acpi_init(void) +{ + printk(KERN_INFO PFX "no support for ACPI processor found." + " Please recompile your kernel with ACPI processor\n"); + return -EINVAL; +} +#endif + +static int powernow_decode_bios (int maxfid, int startvid) +{ + struct psb_s *psb; + struct pst_s *pst; + unsigned int i, j; + unsigned char *p; + unsigned int etuple; + unsigned int ret; + + etuple = cpuid_eax(0x80000001); + + for (i=0xC0000; i < 0xffff0 ; i+=16) { + + p = phys_to_virt(i); + + if (memcmp(p, "AMDK7PNOW!", 10) == 0){ + dprintk ("Found PSB header at %p\n", p); + psb = (struct psb_s *) p; + dprintk ("Table version: 0x%x\n", psb->tableversion); + if (psb->tableversion != 0x12) { + printk (KERN_INFO PFX "Sorry, only v1.2 tables supported right now\n"); + return -ENODEV; + } + + dprintk ("Flags: 0x%x\n", psb->flags); + if ((psb->flags & 1)==0) { + dprintk ("Mobile voltage regulator\n"); + } else { + dprintk ("Desktop voltage regulator\n"); + } + + latency = psb->settlingtime; + if (latency < 100) { + printk (KERN_INFO PFX "BIOS set settling time to %d microseconds." + "Should be at least 100. Correcting.\n", latency); + latency = 100; + } + dprintk ("Settling Time: %d microseconds.\n", psb->settlingtime); + dprintk ("Has %d PST tables. (Only dumping ones relevant to this CPU).\n", psb->numpst); + + p += sizeof (struct psb_s); + + pst = (struct pst_s *) p; + + for (i = 0 ; i <psb->numpst; i++) { + pst = (struct pst_s *) p; + number_scales = pst->numpstates; + + if ((etuple == pst->cpuid) && check_fsb(pst->fsbspeed) && + (maxfid==pst->maxfid) && (startvid==pst->startvid)) + { + dprintk ("PST:%d (@%p)\n", i, pst); + dprintk (" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n", + pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid); + + ret = get_ranges ((char *) pst + sizeof (struct pst_s)); + return ret; + + } else { + p = (char *) pst + sizeof (struct pst_s); + for (j=0 ; j < number_scales; j++) + p+=2; + } + } + printk (KERN_INFO PFX "No PST tables match this cpuid (0x%x)\n", etuple); + printk (KERN_INFO PFX "This is indicative of a broken BIOS.\n"); + + return -EINVAL; + } + p++; + } + + return -ENODEV; +} + + +static int powernow_target (struct cpufreq_policy *policy, + unsigned int target_freq, + unsigned int relation) +{ + unsigned int newstate; + + if (cpufreq_frequency_table_target(policy, powernow_table, target_freq, relation, &newstate)) + return -EINVAL; + + change_speed(newstate); + + return 0; +} + + +static int powernow_verify (struct cpufreq_policy *policy) +{ + return cpufreq_frequency_table_verify(policy, powernow_table); +} + +/* + * We use the fact that the bus frequency is somehow + * a multiple of 100000/3 khz, then we compute sgtc according + * to this multiple. + * That way, we match more how AMD thinks all of that work. + * We will then get the same kind of behaviour already tested under + * the "well-known" other OS. + */ +static int __init fixup_sgtc(void) +{ + unsigned int sgtc; + unsigned int m; + + m = fsb / 3333; + if ((m % 10) >= 5) + m += 5; + + m /= 10; + + sgtc = 100 * m * latency; + sgtc = sgtc / 3; + if (sgtc > 0xfffff) { + printk(KERN_WARNING PFX "SGTC too large %d\n", sgtc); + sgtc = 0xfffff; + } + return sgtc; +} + +static unsigned int powernow_get(unsigned int cpu) +{ + union msr_fidvidstatus fidvidstatus; + unsigned int cfid; + + if (cpu) + return 0; + rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val); + cfid = fidvidstatus.bits.CFID; + + return (fsb * fid_codes[cfid] / 10); +} + + +static int __init acer_cpufreq_pst(struct dmi_system_id *d) +{ + printk(KERN_WARNING "%s laptop with broken PST tables in BIOS detected.\n", d->ident); + printk(KERN_WARNING "You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n"); + printk(KERN_WARNING "cpufreq scaling has been disabled as a result of this.\n"); + return 0; +} + +/* + * Some Athlon laptops have really fucked PST tables. + * A BIOS update is all that can save them. + * Mention this, and disable cpufreq. + */ +static struct dmi_system_id __initdata powernow_dmi_table[] = { + { + .callback = acer_cpufreq_pst, + .ident = "Acer Aspire", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Insyde Software"), + DMI_MATCH(DMI_BIOS_VERSION, "3A71"), + }, + }, + { } +}; + +static int __init powernow_cpu_init (struct cpufreq_policy *policy) +{ + union msr_fidvidstatus fidvidstatus; + int result; + + if (policy->cpu != 0) + return -ENODEV; + + rdmsrl (MSR_K7_FID_VID_STATUS, fidvidstatus.val); + + /* A K7 with powernow technology is set to max frequency by BIOS */ + fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.MFID]; + if (!fsb) { + printk(KERN_WARNING PFX "can not determine bus frequency\n"); + return -EINVAL; + } + dprintk("FSB: %3d.%03d MHz\n", fsb/1000, fsb%1000); + + if (dmi_check_system(powernow_dmi_table) || acpi_force) { + printk (KERN_INFO PFX "PSB/PST known to be broken. Trying ACPI instead\n"); + result = powernow_acpi_init(); + } else { + result = powernow_decode_bios(fidvidstatus.bits.MFID, fidvidstatus.bits.SVID); + if (result) { + printk (KERN_INFO PFX "Trying ACPI perflib\n"); + maximum_speed = 0; + minimum_speed = -1; + latency = 0; + result = powernow_acpi_init(); + if (result) { + printk (KERN_INFO PFX "ACPI and legacy methods failed\n"); + printk (KERN_INFO PFX "See http://www.codemonkey.org.uk/projects/cpufreq/powernow-k7.shtml\n"); + } + } else { + /* SGTC use the bus clock as timer */ + latency = fixup_sgtc(); + printk(KERN_INFO PFX "SGTC: %d\n", latency); + } + } + + if (result) + return result; + + printk (KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n", + minimum_speed/1000, maximum_speed/1000); + + policy->governor = CPUFREQ_DEFAULT_GOVERNOR; + + policy->cpuinfo.transition_latency = cpufreq_scale(2000000UL, fsb, latency); + + policy->cur = powernow_get(0); + + cpufreq_frequency_table_get_attr(powernow_table, policy->cpu); + + return cpufreq_frequency_table_cpuinfo(policy, powernow_table); +} + +static int powernow_cpu_exit (struct cpufreq_policy *policy) { + cpufreq_frequency_table_put_attr(policy->cpu); + +#ifdef CONFIG_X86_POWERNOW_K7_ACPI + if (acpi_processor_perf) { + acpi_processor_unregister_performance(acpi_processor_perf, 0); + kfree(acpi_processor_perf); + } +#endif + + if (powernow_table) + kfree(powernow_table); + + return 0; +} + +static struct freq_attr* powernow_table_attr[] = { + &cpufreq_freq_attr_scaling_available_freqs, + NULL, +}; + +static struct cpufreq_driver powernow_driver = { + .verify = powernow_verify, + .target = powernow_target, + .get = powernow_get, + .init = powernow_cpu_init, + .exit = powernow_cpu_exit, + .name = "powernow-k7", + .owner = THIS_MODULE, + .attr = powernow_table_attr, +}; + +static int __init powernow_init (void) +{ + if (check_powernow()==0) + return -ENODEV; + return cpufreq_register_driver(&powernow_driver); +} + + +static void __exit powernow_exit (void) +{ + cpufreq_unregister_driver(&powernow_driver); +} + +module_param(acpi_force, int, 0444); +MODULE_PARM_DESC(acpi_force, "Force ACPI to be used."); + +MODULE_AUTHOR ("Dave Jones <davej@codemonkey.org.uk>"); +MODULE_DESCRIPTION ("Powernow driver for AMD K7 processors."); +MODULE_LICENSE ("GPL"); + +late_initcall(powernow_init); +module_exit(powernow_exit); + |