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Diffstat (limited to 'src/cpu/intel/speedstep/speedstep.c')
| -rw-r--r-- | src/cpu/intel/speedstep/speedstep.c | 189 |
1 files changed, 189 insertions, 0 deletions
diff --git a/src/cpu/intel/speedstep/speedstep.c b/src/cpu/intel/speedstep/speedstep.c new file mode 100644 index 0000000000..f2cff04dae --- /dev/null +++ b/src/cpu/intel/speedstep/speedstep.c @@ -0,0 +1,189 @@ +/* + * This file is part of the coreboot project. + * + * Copyright (C) 2012 secunet Security Networks AG + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; version 2 of + * the License. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, + * MA 02110-1301 USA + */ + +#include <types.h> +#include <string.h> +#include <arch/cpu.h> +#include <cpu/x86/msr.h> +#include <console/console.h> +#include <cpu/intel/speedstep.h> + +/** + * @brief Gather speedstep limits for current processor + * + * At least power limits are processor type specific. Penryn introduced half + * steps in bus ratios. Don't know about Atom processors. + */ +static void speedstep_get_limits(sst_params_t *const params) +{ + msr_t msr; + + const uint16_t cpu_id = (cpuid_eax(1) >> 4) & 0xffff; + const uint32_t state_mask = + /* Penryn supports non integer (i.e. half) ratios. */ + ((cpu_id == 0x1067) ? SPEEDSTEP_RATIO_NONINT : 0) + | SPEEDSTEP_RATIO_VALUE_MASK | SPEEDSTEP_VID_MASK; + + /* Initialize params to zero. */ + memset(params, '\0', sizeof(*params)); + + /* Read Super-LFM parameters. */ + if (((rdmsr(MSR_EXTENDED_CONFIG).lo >> 27) & 3) == 3) {/*supported and + enabled bits */ + msr = rdmsr(MSR_FSB_CLOCK_VCC); + params->slfm = SPEEDSTEP_STATE_FROM_MSR(msr.lo, state_mask); + params->slfm.dynfsb = 1; + params->slfm.is_slfm = 1; + } + + /* Read normal minimum parameters. */ + msr = rdmsr(MSR_THERM2_CTL); + params->min = SPEEDSTEP_STATE_FROM_MSR(msr.lo, state_mask); + + /* Read normal maximum parameters. */ + /* Newer CPUs provide the normal maximum settings in + IA32_PLATFORM_ID. The values in IA32_PERF_STS change + when using turbo mode. */ + msr = rdmsr(IA32_PLATFORM_ID); + params->max = SPEEDSTEP_STATE_FROM_MSR(msr.lo, state_mask); + if (cpu_id == 0x006e) { + /* Looks like Yonah CPUs don't have the frequency ratio in + IA32_PLATFORM_ID. Use IA32_PERF_STS instead, the reading + should be reliable as those CPUs don't have turbo mode. */ + msr = rdmsr(IA32_PERF_STS); + params->max.ratio = (msr.hi & SPEEDSTEP_RATIO_VALUE_MASK) + >> SPEEDSTEP_RATIO_SHIFT; + } + + /* Read turbo parameters. */ + msr = rdmsr(MSR_FSB_CLOCK_VCC); + if ((msr.hi & (1 << (63 - 32))) && + /* supported and */ + !(rdmsr(IA32_MISC_ENABLES).hi & (1 << (38 - 32)))) { + /* not disabled */ + params->turbo = SPEEDSTEP_STATE_FROM_MSR(msr.hi, state_mask); + params->turbo.is_turbo = 1; + } + + /* Set power limits by processor type. */ + /* Defined values match the normal voltage versions only. But + they are only a hint for OSPM, so this should not hurt much. */ + switch (cpu_id) { + case 0x006e: + /* Yonah */ + params->min.power = SPEEDSTEP_MIN_POWER_YONAH; + params->max.power = SPEEDSTEP_MAX_POWER_YONAH; + break; + case 0x1067: + /* Penryn */ + params->slfm.power = SPEEDSTEP_SLFM_POWER_PENRYN; + params->min.power = SPEEDSTEP_MIN_POWER_PENRYN; + params->max.power = SPEEDSTEP_MAX_POWER_PENRYN; + params->turbo.power = SPEEDSTEP_MAX_POWER_PENRYN; + break; + case 0x006f: + /* Merom */ + default: + /* Use Merom values by default (as before). */ + params->slfm.power = SPEEDSTEP_SLFM_POWER_MEROM; + params->min.power = SPEEDSTEP_MIN_POWER_MEROM; + params->max.power = SPEEDSTEP_MAX_POWER_MEROM; + params->turbo.power = SPEEDSTEP_MAX_POWER_MEROM; + break; + } +} + +/** + * @brief Generate full p-states table from processor parameters + * + * This is generic code and should work at least for Merom and Penryn + * processors. It is used to generate acpi tables and configure EMTTM. + */ +void speedstep_gen_pstates(sst_table_t *const table) +{ + sst_params_t params; + /* Gather speedstep limits. */ + speedstep_get_limits(¶ms); + + + /*\ First, find the number of normal states: \*/ + + /* Calculate with doubled values to work + around non-integer (.5) bus ratios. */ + const int power_diff2 = (params.max.power - params.min.power) * 2; + const int vid_diff2 = (params.max.vid - params.min.vid) * 2; + const int max_ratio2 = SPEEDSTEP_DOUBLE_RATIO(params.max); + const int min_ratio2 = SPEEDSTEP_DOUBLE_RATIO(params.min); + const int ratio_diff2 = max_ratio2 - min_ratio2; + /* Calculate number of normal states (LFM to HFM, min to max). */ + /* Increase step size, until all states fit into the table. + (Note: First try should always work, if + SPEEDSTEP_MAX_NORMAL_STATES is set correctly.) */ + int states, step2 = 0; + do { + step2 += 2 * 2; /* Must be a multiple of 2 (doubled). */ + states = ratio_diff2 / step2 + 1; + } while (states > SPEEDSTEP_MAX_NORMAL_STATES); + if (step2 > 4) + printk(BIOS_INFO, "Enhanced Speedstep processor with " + "more than %d possible p-states.\n", + SPEEDSTEP_MAX_NORMAL_STATES); + if (states < 2) /* Report at least two normal states. */ + states = 2; + + + /*\ Now, fill the table: \*/ + + table->num_states = 0; + + /* Add turbo state if supported. */ + if (params.turbo.is_turbo) + table->states[table->num_states++] = params.turbo; + + /* Add HFM first. */ + table->states[table->num_states] = params.max; + /* Work around HFM and LFM having the same bus ratio. */ + if ((params.max.dynfsb == params.min.dynfsb) && + (params.max.nonint == params.min.nonint) && + (params.max.ratio == params.min.ratio)) + table->states[table->num_states].vid = params.min.vid; + ++table->num_states; + --states; + + /* Now, add all other normal states based on LFM (min). */ + const int power_step = (power_diff2 / states) / 2; + const int vid_step = (vid_diff2 / states) / 2; + const int ratio_step = step2 / 2; + int power = params.min.power + (states - 1) * power_step; + int vid = params.min.vid + (states - 1) * vid_step; + int ratio = params.min.ratio + (states - 1) * ratio_step; + for (; states > 0; --states) { + table->states[table->num_states++] = + (sst_state_t){ 0, 0, ratio, vid, 0, 0, power }; + power -= power_step; + vid -= vid_step; + ratio -= ratio_step; + } + + /* At last, add Super-LFM state if supported. */ + if (params.slfm.is_slfm) + table->states[table->num_states++] = params.slfm; +} |