linux-imx

/*

 *  SFI Performance States Driver

 *

 *  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; either 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.

 *

 *  Author: Vishwesh M Rudramuni <vishwesh.m.rudramuni@intel.com>

 *  Author: Srinidhi Kasagar <srinidhi.kasagar@intel.com>

 */

​

#include <linux/cpufreq.h>

#include <linux/init.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/sfi.h>

#include <linux/slab.h>

#include <linux/smp.h>

​

#include <asm/msr.h>

​

static struct cpufreq_frequency_table *freq_table;

static struct sfi_freq_table_entry *sfi_cpufreq_array;

static int num_freq_table_entries;

​

static int sfi_parse_freq(struct sfi_table_header *table)

{

    struct sfi_table_simple *sb;

    struct sfi_freq_table_entry *pentry;

    int totallen;

​

    sb = (struct sfi_table_simple *)table;

    num_freq_table_entries = SFI_GET_NUM_ENTRIES(sb,

            struct sfi_freq_table_entry);

    if (num_freq_table_entries <= 1) {

        pr_err("No p-states discovered\n");

        return -ENODEV;

    }

​

    pentry = (struct sfi_freq_table_entry *)sb->pentry;

    totallen = num_freq_table_entries * sizeof(*pentry);

​

    sfi_cpufreq_array = kmemdup(pentry, totallen, GFP_KERNEL);

    if (!sfi_cpufreq_array)

        return -ENOMEM;

​

    return 0;

}

​

static int sfi_cpufreq_target(struct cpufreq_policy *policy, unsigned int index)

{

    unsigned int next_perf_state = 0; /* Index into perf table */

    u32 lo, hi;

​

    next_perf_state = policy->freq_table[index].driver_data;

​

    rdmsr_on_cpu(policy->cpu, MSR_IA32_PERF_CTL, &lo, &hi);

    lo = (lo & ~INTEL_PERF_CTL_MASK) |