// SPDX-License-Identifier: GPL-2.0-only /* * AMD K7 Powernow driver. * (C) 2003 Dave Jones on behalf of SuSE Labs. * * Based upon datasheets & sample CPUs kindly provided by AMD. * * Errata 5: * CPU 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: * CPU with half frequency multipliers may hang upon wakeup from disconnect. * - We disable half multipliers if ACPI is used on A0 stepping CPUs. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #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 <linux/timex.h> #include <linux/io.h> #include <asm/timer.h> /* Needed for recalibrate_cpu_khz() */ #include <asm/msr.h> #include <asm/cpu_device_id.h> #ifdef CONFIG_X86_POWERNOW_K7_ACPI #include <linux/acpi.h> #include <acpi/processor.h> #endif #include "powernow-k7.h" 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 /* divide by 1000 to get VCore voltage in V. */ static const 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, }; /* divide by 10 to get FID. */ static const 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; 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 const struct x86_cpu_id powernow_k7_cpuids[] = { { X86_VENDOR_AMD, 6, }, {} }; MODULE_DEVICE_TABLE(x86cpu, powernow_k7_cpuids); static int check_powernow(void) { struct cpuinfo_x86 *c = &cpu_data(0); unsigned int maxei, eax, ebx, ecx, edx; if (!x86_match_cpu(powernow_k7_cpuids)) return 0; /* Get maximum capabilities */ maxei = cpuid_eax(0x80000000); if (maxei < 0x80000007) { /* Any powernow info ? */ #ifdef MODULE pr_info("No powernow capabilities detected\n"); #endif return 0; } if ((c->x86_model == 6) && (c->x86_stepping == 0)) { pr_info("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; pr_info("PowerNOW! Technology present. Can scale: "); if (edx & 1 << 1) { pr_cont("frequency"); can_scale_bus = 1; } if ((edx & (1 << 1 | 1 << 2)) == 0x6) pr_cont(" and "); if (edx & 1 << 2) { pr_cont("voltage"); can_scale_vid = 1; } pr_cont("\n"); return 1; } #ifdef CONFIG_X86_POWERNOW_K7_ACPI static void invalidate_entry(unsigned int entry) { powernow_table[entry].frequency = CPUFREQ_ENTRY_INVALID; } #endif static int get_ranges(unsigned char *pst) { unsigned int j; unsigned int speed; u8 fid, vid; powernow_table = kzalloc((sizeof(*powernow_table) * (number_scales + 1)), GFP_KERNEL); if (!powernow_table) return -ENOMEM; for (j = 0 ; j < number_scales; j++) { fid = *pst++; powernow_table[j].frequency = (fsb * fid_codes[fid]) / 10; powernow_table[j].driver_data = 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) invalidate_entry(j); #endif } if (speed < minimum_speed) minimum_speed = speed; if (speed > maximum_speed) maximum_speed = speed; vid = *pst++; powernow_table[j].driver_data |= (vid << 8); /* upper 8 bits */ pr_debug(" 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].driver_data = 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 int powernow_target(struct cpufreq_policy *policy, 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].driver_data & 0xFF; vid = (powernow_table[index].driver_data & 0xFF00) >> 8; 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; /* 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(); return 0; } #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 = kzalloc(sizeof(*acpi_processor_perf), GFP_KERNEL); if (!acpi_processor_perf) { retval = -ENOMEM; goto err0; } if (!zalloc_cpumask_var(&acpi_processor_perf->shared_cpu_map, GFP_KERNEL)) { retval = -ENOMEM; goto err05; } 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 = kzalloc((sizeof(*powernow_table) * (number_scales + 1)), GFP_KERNEL); if (!powernow_table) { retval = -ENOMEM; goto err2; } pc.val = (unsigned long) acpi_processor_perf->states[0].control; for (i = 0; i < number_scales; i++) { u8 fid, vid; struct acpi_processor_px *state = &acpi_processor_perf->states[i]; unsigned int speed, speed_mhz; pc.val = (unsigned long) state->control; pr_debug("acpi: P%d: %d MHz %d mW %d uS control %08x SGTC %d\n", i, (u32) state->core_frequency, (u32) state->power, (u32) state->transition_latency, (u32) state->control, pc.bits.sgtc); vid = pc.bits.vid; fid = pc.bits.fid; powernow_table[i].frequency = fsb * fid_codes[fid] / 10; powernow_table[i].driver_data = fid; /* lower 8 bits */ powernow_table[i].driver_data |= (vid << 8); /* upper 8 bits */ speed = powernow_table[i].frequency; speed_mhz = speed / 1000; /* processor_perflib will multiply the MHz value by 1000 to * get a KHz value (e.g. 1266000). However, powernow-k7 works * with true KHz values (e.g. 1266768). To ensure that all * powernow frequencies are available, we must ensure that * ACPI doesn't restrict them, so we round up the MHz value * to ensure that perflib's computed KHz value is greater than * or equal to powernow's KHz value. */ if (speed % 1000 > 0) speed_mhz++; if ((fid_codes[fid] % 10) == 5) { if (have_a0 == 1) invalidate_entry(i); } pr_debug(" FID: 0x%x (%d.%dx [%dMHz]) " "VID: 0x%x (%d.%03dV)\n", fid, fid_codes[fid] / 10, fid_codes[fid] % 10, speed_mhz, vid, mobile_vid_table[vid]/1000, mobile_vid_table[vid]%1000); if (state->core_frequency != speed_mhz) { state->core_frequency = speed_mhz; pr_debug(" Corrected ACPI frequency to %d\n", speed_mhz); } 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].driver_data = 0; /* notify BIOS that we exist */ acpi_processor_notify_smm(THIS_MODULE); return 0; err2: acpi_processor_unregister_performance(0); err1: free_cpumask_var(acpi_processor_perf->shared_cpu_map); err05: kfree(acpi_processor_perf); err0: pr_warn("ACPI perflib can not be used on this platform\n"); acpi_processor_perf = NULL; return retval; } #else static int powernow_acpi_init(void) { pr_info("no support for ACPI processor found - please recompile your kernel with ACPI processor\n"); return -EINVAL; } #endif static void print_pst_entry(struct pst_s *pst, unsigned int j) { pr_debug("PST:%d (@%p)\n", j, pst); pr_debug(" cpuid: 0x%x fsb: %d maxFID: 0x%x startvid: 0x%x\n", pst->cpuid, pst->fsbspeed, pst->maxfid, pst->startvid); } 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) { pr_debug("Found PSB header at %p\n", p); psb = (struct psb_s *) p; pr_debug("Table version: 0x%x\n", psb->tableversion); if (psb->tableversion != 0x12) { pr_info("Sorry, only v1.2 tables supported right now\n"); return -ENODEV; } pr_debug("Flags: 0x%x\n", psb->flags); if ((psb->flags & 1) == 0) pr_debug("Mobile voltage regulator\n"); else pr_debug("Desktop voltage regulator\n"); latency = psb->settlingtime; if (latency < 100) { pr_info("BIOS set settling time to %d microseconds. Should be at least 100. Correcting.\n", latency); latency = 100; } pr_debug("Settling Time: %d microseconds.\n", psb->settlingtime); pr_debug("Has %d PST tables. (Only dumping ones " "relevant to this CPU).\n", psb->numpst); p += sizeof(*psb); pst = (struct pst_s *) p; for (j = 0; j < psb->numpst; j++) { pst = (struct pst_s *) p; number_scales = pst->numpstates; if ((etuple == pst->cpuid) && check_fsb(pst->fsbspeed) && (maxfid == pst->maxfid) && (startvid == pst->startvid)) { print_pst_entry(pst, j); p = (char *)pst + sizeof(*pst); ret = get_ranges(p); return ret; } else { unsigned int k; p = (char *)pst + sizeof(*pst); for (k = 0; k < number_scales; k++) p += 2; } } pr_info("No PST tables match this cpuid (0x%x)\n", etuple); pr_info("This is indicative of a broken BIOS\n"); return -EINVAL; } p++; } return -ENODEV; } /* * 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 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) { pr_warn("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 acer_cpufreq_pst(const struct dmi_system_id *d) { pr_warn("%s laptop with broken PST tables in BIOS detected\n", d->ident); pr_warn("You need to downgrade to 3A21 (09/09/2002), or try a newer BIOS than 3A71 (01/20/2003)\n"); pr_warn("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 const struct dmi_system_id 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 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); recalibrate_cpu_khz(); fsb = (10 * cpu_khz) / fid_codes[fidvidstatus.bits.CFID]; if (!fsb) { pr_warn("can not determine bus frequency\n"); return -EINVAL; } pr_debug("FSB: %3dMHz\n", fsb/1000); if (dmi_check_system(powernow_dmi_table) || acpi_force) { pr_info("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) { pr_info("Trying ACPI perflib\n"); maximum_speed = 0; minimum_speed = -1; latency = 0; result = powernow_acpi_init(); if (result) { pr_info("ACPI and legacy methods failed\n"); } } else { /* SGTC use the bus clock as timer */ latency = fixup_sgtc(); pr_info("SGTC: %d\n", latency); } } if (result) return result; pr_info("Minimum speed %d MHz - Maximum speed %d MHz\n", minimum_speed/1000, maximum_speed/1000); policy->cpuinfo.transition_latency = cpufreq_scale(2000000UL, fsb, latency); policy->freq_table = powernow_table; return 0; } static int powernow_cpu_exit(struct cpufreq_policy *policy) { #ifdef CONFIG_X86_POWERNOW_K7_ACPI if (acpi_processor_perf) { acpi_processor_unregister_performance(0); free_cpumask_var(acpi_processor_perf->shared_cpu_map); kfree(acpi_processor_perf); } #endif kfree(powernow_table); return 0; } static struct cpufreq_driver powernow_driver = { .verify = cpufreq_generic_frequency_table_verify, .target_index = powernow_target, .get = powernow_get, #ifdef CONFIG_X86_POWERNOW_K7_ACPI .bios_limit = acpi_processor_get_bios_limit, #endif .init = powernow_cpu_init, .exit = powernow_cpu_exit, .name = "powernow-k7", .attr = cpufreq_generic_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"); MODULE_DESCRIPTION("Powernow driver for AMD K7 processors."); MODULE_LICENSE("GPL"); late_initcall(powernow_init); module_exit(powernow_exit);