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![Joe Perches](/assets/img/avatar_default.png)
Use the more common kernel style adding a define for pr_fmt. Miscellanea: o Remove now unused PFX defines Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
397 lines
9.6 KiB
C
397 lines
9.6 KiB
C
/*
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* Intel SpeedStep SMI driver.
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*
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* (C) 2003 Hiroshi Miura <miura@da-cha.org>
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*
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* Licensed under the terms of the GNU GPL License version 2.
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*
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*/
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/*********************************************************************
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* SPEEDSTEP - DEFINITIONS *
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*********************************************************************/
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#define pr_fmt(fmt) "cpufreq: " fmt
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/init.h>
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#include <linux/cpufreq.h>
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#include <linux/delay.h>
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#include <linux/io.h>
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#include <asm/ist.h>
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#include <asm/cpu_device_id.h>
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#include "speedstep-lib.h"
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/* speedstep system management interface port/command.
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*
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* These parameters are got from IST-SMI BIOS call.
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* If user gives it, these are used.
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*
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*/
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static int smi_port;
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static int smi_cmd;
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static unsigned int smi_sig;
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/* info about the processor */
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static enum speedstep_processor speedstep_processor;
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/*
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* There are only two frequency states for each processor. Values
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* are in kHz for the time being.
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*/
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static struct cpufreq_frequency_table speedstep_freqs[] = {
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{0, SPEEDSTEP_HIGH, 0},
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{0, SPEEDSTEP_LOW, 0},
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{0, 0, CPUFREQ_TABLE_END},
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};
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#define GET_SPEEDSTEP_OWNER 0
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#define GET_SPEEDSTEP_STATE 1
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#define SET_SPEEDSTEP_STATE 2
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#define GET_SPEEDSTEP_FREQS 4
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/* how often shall the SMI call be tried if it failed, e.g. because
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* of DMA activity going on? */
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#define SMI_TRIES 5
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/**
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* speedstep_smi_ownership
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*/
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static int speedstep_smi_ownership(void)
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{
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u32 command, result, magic, dummy;
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u32 function = GET_SPEEDSTEP_OWNER;
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unsigned char magic_data[] = "Copyright (c) 1999 Intel Corporation";
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command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
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magic = virt_to_phys(magic_data);
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pr_debug("trying to obtain ownership with command %x at port %x\n",
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command, smi_port);
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__asm__ __volatile__(
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"push %%ebp\n"
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"out %%al, (%%dx)\n"
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"pop %%ebp\n"
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: "=D" (result),
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"=a" (dummy), "=b" (dummy), "=c" (dummy), "=d" (dummy),
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"=S" (dummy)
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: "a" (command), "b" (function), "c" (0), "d" (smi_port),
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"D" (0), "S" (magic)
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: "memory"
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);
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pr_debug("result is %x\n", result);
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return result;
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}
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/**
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* speedstep_smi_get_freqs - get SpeedStep preferred & current freq.
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* @low: the low frequency value is placed here
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* @high: the high frequency value is placed here
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*
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* Only available on later SpeedStep-enabled systems, returns false results or
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* even hangs [cf. bugme.osdl.org # 1422] on earlier systems. Empirical testing
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* shows that the latter occurs if !(ist_info.event & 0xFFFF).
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*/
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static int speedstep_smi_get_freqs(unsigned int *low, unsigned int *high)
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{
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u32 command, result = 0, edi, high_mhz, low_mhz, dummy;
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u32 state = 0;
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u32 function = GET_SPEEDSTEP_FREQS;
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if (!(ist_info.event & 0xFFFF)) {
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pr_debug("bug #1422 -- can't read freqs from BIOS\n");
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return -ENODEV;
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}
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command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
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pr_debug("trying to determine frequencies with command %x at port %x\n",
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command, smi_port);
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__asm__ __volatile__(
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"push %%ebp\n"
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"out %%al, (%%dx)\n"
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"pop %%ebp"
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: "=a" (result),
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"=b" (high_mhz),
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"=c" (low_mhz),
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"=d" (state), "=D" (edi), "=S" (dummy)
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: "a" (command),
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"b" (function),
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"c" (state),
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"d" (smi_port), "S" (0), "D" (0)
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);
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pr_debug("result %x, low_freq %u, high_freq %u\n",
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result, low_mhz, high_mhz);
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/* abort if results are obviously incorrect... */
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if ((high_mhz + low_mhz) < 600)
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return -EINVAL;
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*high = high_mhz * 1000;
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*low = low_mhz * 1000;
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return result;
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}
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/**
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* speedstep_set_state - set the SpeedStep state
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* @state: new processor frequency state (SPEEDSTEP_LOW or SPEEDSTEP_HIGH)
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*
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*/
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static void speedstep_set_state(unsigned int state)
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{
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unsigned int result = 0, command, new_state, dummy;
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unsigned long flags;
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unsigned int function = SET_SPEEDSTEP_STATE;
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unsigned int retry = 0;
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if (state > 0x1)
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return;
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/* Disable IRQs */
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preempt_disable();
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local_irq_save(flags);
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command = (smi_sig & 0xffffff00) | (smi_cmd & 0xff);
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pr_debug("trying to set frequency to state %u "
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"with command %x at port %x\n",
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state, command, smi_port);
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do {
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if (retry) {
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/*
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* We need to enable interrupts, otherwise the blockage
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* won't resolve.
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*
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* We disable preemption so that other processes don't
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* run. If other processes were running, they could
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* submit more DMA requests, making the blockage worse.
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*/
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pr_debug("retry %u, previous result %u, waiting...\n",
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retry, result);
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local_irq_enable();
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mdelay(retry * 50);
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local_irq_disable();
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}
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retry++;
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__asm__ __volatile__(
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"push %%ebp\n"
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"out %%al, (%%dx)\n"
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"pop %%ebp"
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: "=b" (new_state), "=D" (result),
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"=c" (dummy), "=a" (dummy),
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"=d" (dummy), "=S" (dummy)
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: "a" (command), "b" (function), "c" (state),
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"d" (smi_port), "S" (0), "D" (0)
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);
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} while ((new_state != state) && (retry <= SMI_TRIES));
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/* enable IRQs */
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local_irq_restore(flags);
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preempt_enable();
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if (new_state == state)
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pr_debug("change to %u MHz succeeded after %u tries "
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"with result %u\n",
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(speedstep_freqs[new_state].frequency / 1000),
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retry, result);
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else
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pr_err("change to state %u failed with new_state %u and result %u\n",
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state, new_state, result);
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return;
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}
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/**
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* speedstep_target - set a new CPUFreq policy
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* @policy: new policy
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* @index: index of new freq
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*
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* Sets a new CPUFreq policy/freq.
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*/
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static int speedstep_target(struct cpufreq_policy *policy, unsigned int index)
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{
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speedstep_set_state(index);
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return 0;
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}
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static int speedstep_cpu_init(struct cpufreq_policy *policy)
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{
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int result;
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unsigned int *low, *high;
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/* capability check */
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if (policy->cpu != 0)
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return -ENODEV;
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result = speedstep_smi_ownership();
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if (result) {
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pr_debug("fails in acquiring ownership of a SMI interface.\n");
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return -EINVAL;
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}
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/* detect low and high frequency */
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low = &speedstep_freqs[SPEEDSTEP_LOW].frequency;
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high = &speedstep_freqs[SPEEDSTEP_HIGH].frequency;
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result = speedstep_smi_get_freqs(low, high);
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if (result) {
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/* fall back to speedstep_lib.c dection mechanism:
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* try both states out */
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pr_debug("could not detect low and high frequencies "
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"by SMI call.\n");
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result = speedstep_get_freqs(speedstep_processor,
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low, high,
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NULL,
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&speedstep_set_state);
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if (result) {
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pr_debug("could not detect two different speeds"
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" -- aborting.\n");
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return result;
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} else
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pr_debug("workaround worked.\n");
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}
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policy->cpuinfo.transition_latency = CPUFREQ_ETERNAL;
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return cpufreq_table_validate_and_show(policy, speedstep_freqs);
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}
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static unsigned int speedstep_get(unsigned int cpu)
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{
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if (cpu)
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return -ENODEV;
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return speedstep_get_frequency(speedstep_processor);
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}
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static int speedstep_resume(struct cpufreq_policy *policy)
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{
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int result = speedstep_smi_ownership();
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if (result)
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pr_debug("fails in re-acquiring ownership of a SMI interface.\n");
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return result;
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}
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static struct cpufreq_driver speedstep_driver = {
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.name = "speedstep-smi",
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.verify = cpufreq_generic_frequency_table_verify,
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.target_index = speedstep_target,
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.init = speedstep_cpu_init,
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.get = speedstep_get,
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.resume = speedstep_resume,
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.attr = cpufreq_generic_attr,
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};
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static const struct x86_cpu_id ss_smi_ids[] = {
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{ X86_VENDOR_INTEL, 6, 0xb, },
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{ X86_VENDOR_INTEL, 6, 0x8, },
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{ X86_VENDOR_INTEL, 15, 2 },
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{}
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};
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#if 0
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/* Not auto loaded currently */
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MODULE_DEVICE_TABLE(x86cpu, ss_smi_ids);
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#endif
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/**
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* speedstep_init - initializes the SpeedStep CPUFreq driver
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*
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* Initializes the SpeedStep support. Returns -ENODEV on unsupported
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* BIOS, -EINVAL on problems during initiatization, and zero on
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* success.
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*/
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static int __init speedstep_init(void)
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{
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if (!x86_match_cpu(ss_smi_ids))
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return -ENODEV;
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speedstep_processor = speedstep_detect_processor();
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switch (speedstep_processor) {
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case SPEEDSTEP_CPU_PIII_T:
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case SPEEDSTEP_CPU_PIII_C:
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case SPEEDSTEP_CPU_PIII_C_EARLY:
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break;
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default:
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speedstep_processor = 0;
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}
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if (!speedstep_processor) {
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pr_debug("No supported Intel CPU detected.\n");
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return -ENODEV;
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}
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pr_debug("signature:0x%.8x, command:0x%.8x, "
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"event:0x%.8x, perf_level:0x%.8x.\n",
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ist_info.signature, ist_info.command,
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ist_info.event, ist_info.perf_level);
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/* Error if no IST-SMI BIOS or no PARM
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sig= 'ISGE' aka 'Intel Speedstep Gate E' */
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if ((ist_info.signature != 0x47534943) && (
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(smi_port == 0) || (smi_cmd == 0)))
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return -ENODEV;
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if (smi_sig == 1)
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smi_sig = 0x47534943;
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else
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smi_sig = ist_info.signature;
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/* setup smi_port from MODLULE_PARM or BIOS */
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if ((smi_port > 0xff) || (smi_port < 0))
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return -EINVAL;
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else if (smi_port == 0)
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smi_port = ist_info.command & 0xff;
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if ((smi_cmd > 0xff) || (smi_cmd < 0))
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return -EINVAL;
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else if (smi_cmd == 0)
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smi_cmd = (ist_info.command >> 16) & 0xff;
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return cpufreq_register_driver(&speedstep_driver);
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}
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/**
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* speedstep_exit - unregisters SpeedStep support
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*
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* Unregisters SpeedStep support.
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*/
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static void __exit speedstep_exit(void)
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{
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cpufreq_unregister_driver(&speedstep_driver);
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}
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module_param(smi_port, int, 0444);
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module_param(smi_cmd, int, 0444);
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module_param(smi_sig, uint, 0444);
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MODULE_PARM_DESC(smi_port, "Override the BIOS-given IST port with this value "
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"-- Intel's default setting is 0xb2");
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MODULE_PARM_DESC(smi_cmd, "Override the BIOS-given IST command with this value "
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"-- Intel's default setting is 0x82");
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MODULE_PARM_DESC(smi_sig, "Set to 1 to fake the IST signature when using the "
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"SMI interface.");
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MODULE_AUTHOR("Hiroshi Miura");
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MODULE_DESCRIPTION("Speedstep driver for IST applet SMI interface.");
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MODULE_LICENSE("GPL");
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module_init(speedstep_init);
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module_exit(speedstep_exit);
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