/* * $Id: powernow-k7.c,v 1.34 2003/02/22 10:23:46 db Exp $ * * (C) 2003 Dave Jones <davej@suse.de> * * Licensed under the terms of the GNU GPL License version 2. * Based upon datasheets & sample CPUs kindly provided by AMD. * * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous* * * 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/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/cpufreq.h> #include <linux/slab.h> #include <linux/string.h> #include <asm/msr.h> #include <asm/timex.h> #include <asm/io.h> #include <asm/system.h> #include "powernow-k7.h" #define DEBUG #ifdef DEBUG #define dprintk(msg...) printk(msg) #else #define dprintk(msg...) do { } while(0) #endif #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; }; /* divide by 1000 to get VID. */ 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, 1024, 1000, 975, 950, 925, 0, }; /* 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, }; 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; #ifndef rdmsrl #define rdmsrl(msr,val) do {unsigned long l__,h__; \ rdmsr (msr, l__, h__); \ val = l__; \ val |= ((u64)h__<<32); \ } while(0) #endif #ifndef wrmsrl static void wrmsrl (u32 msr, u64 val) { u32 lo, hi; lo = (u32) val; hi = val >> 32; wrmsr (msr, lo, hi); } #endif 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) { printk (KERN_INFO PFX "AMD processor not detected.\n"); return 0; } if (c->x86 !=6) { printk (KERN_INFO PFX "This module only works with AMD K7 CPUs\n"); return 0; } printk (KERN_INFO PFX "AMD K7 CPU detected.\n"); 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; } /* Get maximum capabilities */ maxei = cpuid_eax (0x80000000); if (maxei < 0x80000007) { /* Any powernow info ? */ printk (KERN_INFO PFX "No powernow capabilities detected\n"); return 0; } cpuid(0x80000007, &eax, &ebx, &ecx, &edx); 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; } if (!(edx & (1 << 1 | 1 << 2))) { printk ("nothing.\n"); return 0; } printk (".\n"); return 1; } static int get_ranges (unsigned char *pst) { unsigned int j, 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] * 100; powernow_table[j].index = fid; /* lower 8 bits */ speed = fsb * (fid_codes[fid]/10); if ((fid_codes[fid] % 10)==5) { speed += fsb/2; #if defined(CONFIG_ACPI_PROCESSOR) || defined(CONFIG_ACPI_PROCESSOR_MODULE) if (have_a0 == 1) powernow_table[j].frequency = CPUFREQ_ENTRY_INVALID; #endif } dprintk (KERN_INFO PFX " FID: 0x%x (%d.%dx [%dMHz])\t", fid, fid_codes[fid] / 10, fid_codes[fid] % 10, speed); 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 ("VID: 0x%x (%d.%03dV)\n", vid, mobile_vid_table[vid]/1000, mobile_vid_table[vid]%1000); } dprintk ("\n"); 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; if (fidvidctl.bits.FID != fid) { rdmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val); fidvidctl.bits.SGTC = latency; fidvidctl.bits.FID = fid; fidvidctl.bits.FIDC = 1; wrmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val); } } static void change_VID(int vid) { union msr_fidvidctl fidvidctl; if (fidvidctl.bits.VID != vid) { rdmsrl (MSR_K7_FID_VID_CTL, fidvidctl.val); fidvidctl.bits.VID = vid; 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; /* 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); freqs.old = fsb * fid_codes[fidvidstatus.bits.CFID] * 100; 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); } static int powernow_decode_bios (int maxfid, int startvid) { struct psb_s *psb; struct pst_s *pst; struct cpuinfo_x86 *c = cpu_data; unsigned int i, j; unsigned char *p; unsigned int etuple; unsigned int ret; etuple = cpuid_eax(0x80000001); etuple &= 0xf00; etuple |= (c->x86_model<<4)|(c->x86_mask); for (i=0xC0000; i < 0xffff0 ; i+=16) { p = phys_to_virt(i); if (memcmp(p, "AMDK7PNOW!", 10) == 0){ dprintk (KERN_INFO PFX "Found PSB header at %p\n", p); psb = (struct psb_s *) p; dprintk (KERN_INFO PFX "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 (KERN_INFO PFX "Flags: 0x%x (", psb->flags); if ((psb->flags & 1)==0) { dprintk ("Mobile"); } else { dprintk ("Desktop"); } dprintk (" voltage regulator)\n"); latency = psb->settlingtime; dprintk (KERN_INFO PFX "Settling Time: %d microseconds.\n", psb->settlingtime); dprintk (KERN_INFO PFX "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) && (maxfid==pst->maxfid) && (startvid==pst->startvid)) { dprintk (KERN_INFO PFX "PST:%d (@%p)\n", i, pst); dprintk (KERN_INFO PFX " cpuid: 0x%x\t", pst->cpuid); dprintk ("fsb: %d\t", pst->fsbspeed); dprintk ("maxFID: 0x%x\t", pst->maxfid); dprintk ("startvid: 0x%x\n", pst->startvid); fsb = pst->fsbspeed; 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; } } 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); } 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); result = powernow_decode_bios(fidvidstatus.bits.MFID, fidvidstatus.bits.SVID); if (result) return result; printk (KERN_INFO PFX "Minimum speed %d MHz. Maximum speed %d MHz.\n", minimum_speed, maximum_speed); policy->policy = CPUFREQ_POLICY_PERFORMANCE; policy->cpuinfo.transition_latency = latency; policy->cur = maximum_speed; return cpufreq_frequency_table_cpuinfo(policy, powernow_table); } static struct cpufreq_driver powernow_driver = { .verify = powernow_verify, .target = powernow_target, .init = powernow_cpu_init, .name = "powernow-k7", .owner = THIS_MODULE, }; static int __init powernow_init (void) { if (dmi_broken & BROKEN_CPUFREQ) { printk (KERN_INFO PFX "Disabled at boot time by DMI,\n"); return -ENODEV; } if (check_powernow()==0) return -ENODEV; return cpufreq_register_driver(&powernow_driver); } static void __exit powernow_exit (void) { cpufreq_unregister_driver(&powernow_driver); if (powernow_table) kfree(powernow_table); } MODULE_AUTHOR ("Dave Jones <davej@suse.de>"); MODULE_DESCRIPTION ("Powernow driver for AMD K7 processors."); MODULE_LICENSE ("GPL"); module_init(powernow_init); module_exit(powernow_exit);