From bb0a56ecc4ba2a3db1b6ea6949c309886e3447d3 Mon Sep 17 00:00:00 2001 From: Dave Jones Date: Thu, 19 May 2011 18:51:07 -0400 Subject: [CPUFREQ] Move x86 drivers to drivers/cpufreq/ Signed-off-by: Dave Jones --- drivers/cpufreq/longrun.c | 324 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 324 insertions(+) create mode 100644 drivers/cpufreq/longrun.c (limited to 'drivers/cpufreq/longrun.c') diff --git a/drivers/cpufreq/longrun.c b/drivers/cpufreq/longrun.c new file mode 100644 index 00000000000..34ea359b370 --- /dev/null +++ b/drivers/cpufreq/longrun.c @@ -0,0 +1,324 @@ +/* + * (C) 2002 - 2003 Dominik Brodowski + * + * Licensed under the terms of the GNU GPL License version 2. + * + * BIG FAT DISCLAIMER: Work in progress code. Possibly *dangerous* + */ + +#include +#include +#include +#include +#include + +#include +#include + +static struct cpufreq_driver longrun_driver; + +/** + * longrun_{low,high}_freq is needed for the conversion of cpufreq kHz + * values into per cent values. In TMTA microcode, the following is valid: + * performance_pctg = (current_freq - low_freq)/(high_freq - low_freq) + */ +static unsigned int longrun_low_freq, longrun_high_freq; + + +/** + * longrun_get_policy - get the current LongRun policy + * @policy: struct cpufreq_policy where current policy is written into + * + * Reads the current LongRun policy by access to MSR_TMTA_LONGRUN_FLAGS + * and MSR_TMTA_LONGRUN_CTRL + */ +static void __cpuinit longrun_get_policy(struct cpufreq_policy *policy) +{ + u32 msr_lo, msr_hi; + + rdmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi); + pr_debug("longrun flags are %x - %x\n", msr_lo, msr_hi); + if (msr_lo & 0x01) + policy->policy = CPUFREQ_POLICY_PERFORMANCE; + else + policy->policy = CPUFREQ_POLICY_POWERSAVE; + + rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi); + pr_debug("longrun ctrl is %x - %x\n", msr_lo, msr_hi); + msr_lo &= 0x0000007F; + msr_hi &= 0x0000007F; + + if (longrun_high_freq <= longrun_low_freq) { + /* Assume degenerate Longrun table */ + policy->min = policy->max = longrun_high_freq; + } else { + policy->min = longrun_low_freq + msr_lo * + ((longrun_high_freq - longrun_low_freq) / 100); + policy->max = longrun_low_freq + msr_hi * + ((longrun_high_freq - longrun_low_freq) / 100); + } + policy->cpu = 0; +} + + +/** + * longrun_set_policy - sets a new CPUFreq policy + * @policy: new policy + * + * Sets a new CPUFreq policy on LongRun-capable processors. This function + * has to be called with cpufreq_driver locked. + */ +static int longrun_set_policy(struct cpufreq_policy *policy) +{ + u32 msr_lo, msr_hi; + u32 pctg_lo, pctg_hi; + + if (!policy) + return -EINVAL; + + if (longrun_high_freq <= longrun_low_freq) { + /* Assume degenerate Longrun table */ + pctg_lo = pctg_hi = 100; + } else { + pctg_lo = (policy->min - longrun_low_freq) / + ((longrun_high_freq - longrun_low_freq) / 100); + pctg_hi = (policy->max - longrun_low_freq) / + ((longrun_high_freq - longrun_low_freq) / 100); + } + + if (pctg_hi > 100) + pctg_hi = 100; + if (pctg_lo > pctg_hi) + pctg_lo = pctg_hi; + + /* performance or economy mode */ + rdmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi); + msr_lo &= 0xFFFFFFFE; + switch (policy->policy) { + case CPUFREQ_POLICY_PERFORMANCE: + msr_lo |= 0x00000001; + break; + case CPUFREQ_POLICY_POWERSAVE: + break; + } + wrmsr(MSR_TMTA_LONGRUN_FLAGS, msr_lo, msr_hi); + + /* lower and upper boundary */ + rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi); + msr_lo &= 0xFFFFFF80; + msr_hi &= 0xFFFFFF80; + msr_lo |= pctg_lo; + msr_hi |= pctg_hi; + wrmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi); + + return 0; +} + + +/** + * longrun_verify_poliy - verifies a new CPUFreq policy + * @policy: the policy to verify + * + * Validates a new CPUFreq policy. This function has to be called with + * cpufreq_driver locked. + */ +static int longrun_verify_policy(struct cpufreq_policy *policy) +{ + if (!policy) + return -EINVAL; + + policy->cpu = 0; + cpufreq_verify_within_limits(policy, + policy->cpuinfo.min_freq, + policy->cpuinfo.max_freq); + + if ((policy->policy != CPUFREQ_POLICY_POWERSAVE) && + (policy->policy != CPUFREQ_POLICY_PERFORMANCE)) + return -EINVAL; + + return 0; +} + +static unsigned int longrun_get(unsigned int cpu) +{ + u32 eax, ebx, ecx, edx; + + if (cpu) + return 0; + + cpuid(0x80860007, &eax, &ebx, &ecx, &edx); + pr_debug("cpuid eax is %u\n", eax); + + return eax * 1000; +} + +/** + * longrun_determine_freqs - determines the lowest and highest possible core frequency + * @low_freq: an int to put the lowest frequency into + * @high_freq: an int to put the highest frequency into + * + * Determines the lowest and highest possible core frequencies on this CPU. + * This is necessary to calculate the performance percentage according to + * TMTA rules: + * performance_pctg = (target_freq - low_freq)/(high_freq - low_freq) + */ +static int __cpuinit longrun_determine_freqs(unsigned int *low_freq, + unsigned int *high_freq) +{ + u32 msr_lo, msr_hi; + u32 save_lo, save_hi; + u32 eax, ebx, ecx, edx; + u32 try_hi; + struct cpuinfo_x86 *c = &cpu_data(0); + + if (!low_freq || !high_freq) + return -EINVAL; + + if (cpu_has(c, X86_FEATURE_LRTI)) { + /* if the LongRun Table Interface is present, the + * detection is a bit easier: + * For minimum frequency, read out the maximum + * level (msr_hi), write that into "currently + * selected level", and read out the frequency. + * For maximum frequency, read out level zero. + */ + /* minimum */ + rdmsr(MSR_TMTA_LRTI_READOUT, msr_lo, msr_hi); + wrmsr(MSR_TMTA_LRTI_READOUT, msr_hi, msr_hi); + rdmsr(MSR_TMTA_LRTI_VOLT_MHZ, msr_lo, msr_hi); + *low_freq = msr_lo * 1000; /* to kHz */ + + /* maximum */ + wrmsr(MSR_TMTA_LRTI_READOUT, 0, msr_hi); + rdmsr(MSR_TMTA_LRTI_VOLT_MHZ, msr_lo, msr_hi); + *high_freq = msr_lo * 1000; /* to kHz */ + + pr_debug("longrun table interface told %u - %u kHz\n", + *low_freq, *high_freq); + + if (*low_freq > *high_freq) + *low_freq = *high_freq; + return 0; + } + + /* set the upper border to the value determined during TSC init */ + *high_freq = (cpu_khz / 1000); + *high_freq = *high_freq * 1000; + pr_debug("high frequency is %u kHz\n", *high_freq); + + /* get current borders */ + rdmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi); + save_lo = msr_lo & 0x0000007F; + save_hi = msr_hi & 0x0000007F; + + /* if current perf_pctg is larger than 90%, we need to decrease the + * upper limit to make the calculation more accurate. + */ + cpuid(0x80860007, &eax, &ebx, &ecx, &edx); + /* try decreasing in 10% steps, some processors react only + * on some barrier values */ + for (try_hi = 80; try_hi > 0 && ecx > 90; try_hi -= 10) { + /* set to 0 to try_hi perf_pctg */ + msr_lo &= 0xFFFFFF80; + msr_hi &= 0xFFFFFF80; + msr_hi |= try_hi; + wrmsr(MSR_TMTA_LONGRUN_CTRL, msr_lo, msr_hi); + + /* read out current core MHz and current perf_pctg */ + cpuid(0x80860007, &eax, &ebx, &ecx, &edx); + + /* restore values */ + wrmsr(MSR_TMTA_LONGRUN_CTRL, save_lo, save_hi); + } + pr_debug("percentage is %u %%, freq is %u MHz\n", ecx, eax); + + /* performance_pctg = (current_freq - low_freq)/(high_freq - low_freq) + * eqals + * low_freq * (1 - perf_pctg) = (cur_freq - high_freq * perf_pctg) + * + * high_freq * perf_pctg is stored tempoarily into "ebx". + */ + ebx = (((cpu_khz / 1000) * ecx) / 100); /* to MHz */ + + if ((ecx > 95) || (ecx == 0) || (eax < ebx)) + return -EIO; + + edx = ((eax - ebx) * 100) / (100 - ecx); + *low_freq = edx * 1000; /* back to kHz */ + + pr_debug("low frequency is %u kHz\n", *low_freq); + + if (*low_freq > *high_freq) + *low_freq = *high_freq; + + return 0; +} + + +static int __cpuinit longrun_cpu_init(struct cpufreq_policy *policy) +{ + int result = 0; + + /* capability check */ + if (policy->cpu != 0) + return -ENODEV; + + /* detect low and high frequency */ + result = longrun_determine_freqs(&longrun_low_freq, &longrun_high_freq); + if (result) + return result; + + /* cpuinfo and default policy values */ + policy->cpuinfo.min_freq = longrun_low_freq; + policy->cpuinfo.max_freq = longrun_high_freq; + policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL; + longrun_get_policy(policy); + + return 0; +} + + +static struct cpufreq_driver longrun_driver = { + .flags = CPUFREQ_CONST_LOOPS, + .verify = longrun_verify_policy, + .setpolicy = longrun_set_policy, + .get = longrun_get, + .init = longrun_cpu_init, + .name = "longrun", + .owner = THIS_MODULE, +}; + + +/** + * longrun_init - initializes the Transmeta Crusoe LongRun CPUFreq driver + * + * Initializes the LongRun support. + */ +static int __init longrun_init(void) +{ + struct cpuinfo_x86 *c = &cpu_data(0); + + if (c->x86_vendor != X86_VENDOR_TRANSMETA || + !cpu_has(c, X86_FEATURE_LONGRUN)) + return -ENODEV; + + return cpufreq_register_driver(&longrun_driver); +} + + +/** + * longrun_exit - unregisters LongRun support + */ +static void __exit longrun_exit(void) +{ + cpufreq_unregister_driver(&longrun_driver); +} + + +MODULE_AUTHOR("Dominik Brodowski "); +MODULE_DESCRIPTION("LongRun driver for Transmeta Crusoe and " + "Efficeon processors."); +MODULE_LICENSE("GPL"); + +module_init(longrun_init); +module_exit(longrun_exit); -- cgit v1.2.3