diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 18:49:45 +0000 |
commit | 2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch) | |
tree | 848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/cpufreq/powernow-k6.c | |
parent | Initial commit. (diff) | |
download | linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip |
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/cpufreq/powernow-k6.c')
-rw-r--r-- | drivers/cpufreq/powernow-k6.c | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/drivers/cpufreq/powernow-k6.c b/drivers/cpufreq/powernow-k6.c new file mode 100644 index 000000000..41eefef95 --- /dev/null +++ b/drivers/cpufreq/powernow-k6.c @@ -0,0 +1,311 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * This file was based upon code in Powertweak Linux (http://powertweak.sf.net) + * (C) 2000-2003 Dave Jones, Arjan van de Ven, Janne Pänkälä, + * Dominik Brodowski. + * + * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous* + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/cpufreq.h> +#include <linux/ioport.h> +#include <linux/timex.h> +#include <linux/io.h> + +#include <asm/cpu_device_id.h> +#include <asm/msr.h> + +#define POWERNOW_IOPORT 0xfff0 /* it doesn't matter where, as long + as it is unused */ + +static unsigned int busfreq; /* FSB, in 10 kHz */ +static unsigned int max_multiplier; + +static unsigned int param_busfreq = 0; +static unsigned int param_max_multiplier = 0; + +module_param_named(max_multiplier, param_max_multiplier, uint, S_IRUGO); +MODULE_PARM_DESC(max_multiplier, "Maximum multiplier (allowed values: 20 30 35 40 45 50 55 60)"); + +module_param_named(bus_frequency, param_busfreq, uint, S_IRUGO); +MODULE_PARM_DESC(bus_frequency, "Bus frequency in kHz"); + +/* Clock ratio multiplied by 10 - see table 27 in AMD#23446 */ +static struct cpufreq_frequency_table clock_ratio[] = { + {0, 60, /* 110 -> 6.0x */ 0}, + {0, 55, /* 011 -> 5.5x */ 0}, + {0, 50, /* 001 -> 5.0x */ 0}, + {0, 45, /* 000 -> 4.5x */ 0}, + {0, 40, /* 010 -> 4.0x */ 0}, + {0, 35, /* 111 -> 3.5x */ 0}, + {0, 30, /* 101 -> 3.0x */ 0}, + {0, 20, /* 100 -> 2.0x */ 0}, + {0, 0, CPUFREQ_TABLE_END} +}; + +static const u8 index_to_register[8] = { 6, 3, 1, 0, 2, 7, 5, 4 }; +static const u8 register_to_index[8] = { 3, 2, 4, 1, 7, 6, 0, 5 }; + +static const struct { + unsigned freq; + unsigned mult; +} usual_frequency_table[] = { + { 350000, 35 }, // 100 * 3.5 + { 400000, 40 }, // 100 * 4 + { 450000, 45 }, // 100 * 4.5 + { 475000, 50 }, // 95 * 5 + { 500000, 50 }, // 100 * 5 + { 506250, 45 }, // 112.5 * 4.5 + { 533500, 55 }, // 97 * 5.5 + { 550000, 55 }, // 100 * 5.5 + { 562500, 50 }, // 112.5 * 5 + { 570000, 60 }, // 95 * 6 + { 600000, 60 }, // 100 * 6 + { 618750, 55 }, // 112.5 * 5.5 + { 660000, 55 }, // 120 * 5.5 + { 675000, 60 }, // 112.5 * 6 + { 720000, 60 }, // 120 * 6 +}; + +#define FREQ_RANGE 3000 + +/** + * powernow_k6_get_cpu_multiplier - returns the current FSB multiplier + * + * Returns the current setting of the frequency multiplier. Core clock + * speed is frequency of the Front-Side Bus multiplied with this value. + */ +static int powernow_k6_get_cpu_multiplier(void) +{ + unsigned long invalue = 0; + u32 msrval; + + local_irq_disable(); + + msrval = POWERNOW_IOPORT + 0x1; + wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */ + invalue = inl(POWERNOW_IOPORT + 0x8); + msrval = POWERNOW_IOPORT + 0x0; + wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */ + + local_irq_enable(); + + return clock_ratio[register_to_index[(invalue >> 5)&7]].driver_data; +} + +static void powernow_k6_set_cpu_multiplier(unsigned int best_i) +{ + unsigned long outvalue, invalue; + unsigned long msrval; + unsigned long cr0; + + /* we now need to transform best_i to the BVC format, see AMD#23446 */ + + /* + * The processor doesn't respond to inquiry cycles while changing the + * frequency, so we must disable cache. + */ + local_irq_disable(); + cr0 = read_cr0(); + write_cr0(cr0 | X86_CR0_CD); + wbinvd(); + + outvalue = (1<<12) | (1<<10) | (1<<9) | (index_to_register[best_i]<<5); + + msrval = POWERNOW_IOPORT + 0x1; + wrmsr(MSR_K6_EPMR, msrval, 0); /* enable the PowerNow port */ + invalue = inl(POWERNOW_IOPORT + 0x8); + invalue = invalue & 0x1f; + outvalue = outvalue | invalue; + outl(outvalue, (POWERNOW_IOPORT + 0x8)); + msrval = POWERNOW_IOPORT + 0x0; + wrmsr(MSR_K6_EPMR, msrval, 0); /* disable it again */ + + write_cr0(cr0); + local_irq_enable(); +} + +/** + * powernow_k6_target - set the PowerNow! multiplier + * @best_i: clock_ratio[best_i] is the target multiplier + * + * Tries to change the PowerNow! multiplier + */ +static int powernow_k6_target(struct cpufreq_policy *policy, + unsigned int best_i) +{ + + if (clock_ratio[best_i].driver_data > max_multiplier) { + pr_err("invalid target frequency\n"); + return -EINVAL; + } + + powernow_k6_set_cpu_multiplier(best_i); + + return 0; +} + +static int powernow_k6_cpu_init(struct cpufreq_policy *policy) +{ + struct cpufreq_frequency_table *pos; + unsigned int i, f; + unsigned khz; + + if (policy->cpu != 0) + return -ENODEV; + + max_multiplier = 0; + khz = cpu_khz; + for (i = 0; i < ARRAY_SIZE(usual_frequency_table); i++) { + if (khz >= usual_frequency_table[i].freq - FREQ_RANGE && + khz <= usual_frequency_table[i].freq + FREQ_RANGE) { + khz = usual_frequency_table[i].freq; + max_multiplier = usual_frequency_table[i].mult; + break; + } + } + if (param_max_multiplier) { + cpufreq_for_each_entry(pos, clock_ratio) + if (pos->driver_data == param_max_multiplier) { + max_multiplier = param_max_multiplier; + goto have_max_multiplier; + } + pr_err("invalid max_multiplier parameter, valid parameters 20, 30, 35, 40, 45, 50, 55, 60\n"); + return -EINVAL; + } + + if (!max_multiplier) { + pr_warn("unknown frequency %u, cannot determine current multiplier\n", + khz); + pr_warn("use module parameters max_multiplier and bus_frequency\n"); + return -EOPNOTSUPP; + } + +have_max_multiplier: + param_max_multiplier = max_multiplier; + + if (param_busfreq) { + if (param_busfreq >= 50000 && param_busfreq <= 150000) { + busfreq = param_busfreq / 10; + goto have_busfreq; + } + pr_err("invalid bus_frequency parameter, allowed range 50000 - 150000 kHz\n"); + return -EINVAL; + } + + busfreq = khz / max_multiplier; +have_busfreq: + param_busfreq = busfreq * 10; + + /* table init */ + cpufreq_for_each_entry(pos, clock_ratio) { + f = pos->driver_data; + if (f > max_multiplier) + pos->frequency = CPUFREQ_ENTRY_INVALID; + else + pos->frequency = busfreq * f; + } + + /* cpuinfo and default policy values */ + policy->cpuinfo.transition_latency = 500000; + policy->freq_table = clock_ratio; + + return 0; +} + + +static int powernow_k6_cpu_exit(struct cpufreq_policy *policy) +{ + unsigned int i; + + for (i = 0; (clock_ratio[i].frequency != CPUFREQ_TABLE_END); i++) { + if (clock_ratio[i].driver_data == max_multiplier) { + struct cpufreq_freqs freqs; + + freqs.old = policy->cur; + freqs.new = clock_ratio[i].frequency; + freqs.flags = 0; + + cpufreq_freq_transition_begin(policy, &freqs); + powernow_k6_target(policy, i); + cpufreq_freq_transition_end(policy, &freqs, 0); + break; + } + } + return 0; +} + +static unsigned int powernow_k6_get(unsigned int cpu) +{ + unsigned int ret; + ret = (busfreq * powernow_k6_get_cpu_multiplier()); + return ret; +} + +static struct cpufreq_driver powernow_k6_driver = { + .verify = cpufreq_generic_frequency_table_verify, + .target_index = powernow_k6_target, + .init = powernow_k6_cpu_init, + .exit = powernow_k6_cpu_exit, + .get = powernow_k6_get, + .name = "powernow-k6", + .attr = cpufreq_generic_attr, +}; + +static const struct x86_cpu_id powernow_k6_ids[] = { + X86_MATCH_VENDOR_FAM_MODEL(AMD, 5, 12, NULL), + X86_MATCH_VENDOR_FAM_MODEL(AMD, 5, 13, NULL), + {} +}; +MODULE_DEVICE_TABLE(x86cpu, powernow_k6_ids); + +/** + * powernow_k6_init - initializes the k6 PowerNow! CPUFreq driver + * + * Initializes the K6 PowerNow! support. Returns -ENODEV on unsupported + * devices, -EINVAL or -ENOMEM on problems during initiatization, and zero + * on success. + */ +static int __init powernow_k6_init(void) +{ + if (!x86_match_cpu(powernow_k6_ids)) + return -ENODEV; + + if (!request_region(POWERNOW_IOPORT, 16, "PowerNow!")) { + pr_info("PowerNow IOPORT region already used\n"); + return -EIO; + } + + if (cpufreq_register_driver(&powernow_k6_driver)) { + release_region(POWERNOW_IOPORT, 16); + return -EINVAL; + } + + return 0; +} + + +/** + * powernow_k6_exit - unregisters AMD K6-2+/3+ PowerNow! support + * + * Unregisters AMD K6-2+ / K6-3+ PowerNow! support. + */ +static void __exit powernow_k6_exit(void) +{ + cpufreq_unregister_driver(&powernow_k6_driver); + release_region(POWERNOW_IOPORT, 16); +} + + +MODULE_AUTHOR("Arjan van de Ven, Dave Jones, " + "Dominik Brodowski <linux@brodo.de>"); +MODULE_DESCRIPTION("PowerNow! driver for AMD K6-2+ / K6-3+ processors."); +MODULE_LICENSE("GPL"); + +module_init(powernow_k6_init); +module_exit(powernow_k6_exit); |