drivers/gator/gator_iks.c

/**
 * Copyright (C) Arm Limited 2013-2016. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#if GATOR_IKS_SUPPORT

#include <linux/of.h>
#include <asm/bL_switcher.h>
#include <asm/smp_plat.h>
#include <trace/events/power_cpu_migrate.h>

static bool map_cpuids;
static int mpidr_cpuids[NR_CPUS];
static const struct gator_cpu *mpidr_cpus[NR_CPUS];
static int __lcpu_to_pcpu[NR_CPUS];

static const struct gator_cpu *gator_find_cpu_by_dt_name(const char *const name)
{
    const struct gator_cpu *gator_cpu;

    list_for_each_entry(gator_cpu, &gator_cpus, list) {
        if (gator_cpu->dt_name != NULL && strcmp(gator_cpu->dt_name, name) == 0)
            return gator_cpu;
    }

    return NULL;
}

static void calc_first_cluster_size(void)
{
    int len;
    const u32 *val;
    const char *compatible;
    struct device_node *cn = NULL;
    int mpidr_cpuids_count = 0;

    /* Zero is a valid cpuid, so initialize the array to 0xff's */
    memset(&mpidr_cpuids, 0xff, sizeof(mpidr_cpuids));
    memset(&mpidr_cpus, 0, sizeof(mpidr_cpus));

    while ((cn = of_find_node_by_type(cn, "cpu"))) {
        BUG_ON(mpidr_cpuids_count >= NR_CPUS);

        val = of_get_property(cn, "reg", &len);
        if (!val || len != 4) {
            pr_err("%s missing reg property\n", cn->full_name);
            continue;
        }
        compatible = of_get_property(cn, "compatible", NULL);
        if (compatible == NULL) {
            pr_err("%s missing compatible property\n", cn->full_name);
            continue;
        }

        mpidr_cpuids[mpidr_cpuids_count] = be32_to_cpup(val);
        mpidr_cpus[mpidr_cpuids_count] = gator_find_cpu_by_dt_name(compatible);
        ++mpidr_cpuids_count;
    }

    map_cpuids = (mpidr_cpuids_count == nr_cpu_ids);
}

static int linearize_mpidr(int mpidr)
{
    int i;

    for (i = 0; i < nr_cpu_ids; ++i) {
        if (mpidr_cpuids[i] == mpidr)
            return i;
    }

    BUG();
}

int lcpu_to_pcpu(const int lcpu)
{
    int pcpu;

    if (!map_cpuids)
        return lcpu;

    BUG_ON(lcpu >= nr_cpu_ids || lcpu < 0);
    pcpu = __lcpu_to_pcpu[lcpu];
    BUG_ON(pcpu >= nr_cpu_ids || pcpu < 0);
    return pcpu;
}

int pcpu_to_lcpu(const int pcpu)
{
    int lcpu;

    if (!map_cpuids)
        return pcpu;

    BUG_ON(pcpu >= nr_cpu_ids || pcpu < 0);
    for (lcpu = 0; lcpu < nr_cpu_ids; ++lcpu) {
        if (__lcpu_to_pcpu[lcpu] == pcpu) {
            BUG_ON(lcpu >= nr_cpu_ids || lcpu < 0);
            return lcpu;
        }
    }
    BUG();
}

static void gator_update_cpu_mapping(u32 cpu_hwid)
{
    int lcpu = smp_processor_id();
    int pcpu = linearize_mpidr(cpu_hwid & MPIDR_HWID_BITMASK);

    BUG_ON(lcpu >= nr_cpu_ids || lcpu < 0);
    BUG_ON(pcpu >= nr_cpu_ids || pcpu < 0);
    __lcpu_to_pcpu[lcpu] = pcpu;
}

GATOR_DEFINE_PROBE(cpu_migrate_begin, TP_PROTO(u64 timestamp, u32 cpu_hwid))
{
    const int cpu = get_physical_cpu();

    gator_timer_offline((void *)1);
    gator_timer_offline_dispatch(cpu, true);
}

GATOR_DEFINE_PROBE(cpu_migrate_finish, TP_PROTO(u64 timestamp, u32 cpu_hwid))
{
    int cpu;

    gator_update_cpu_mapping(cpu_hwid);

    /* get_physical_cpu must be called after gator_update_cpu_mapping */
    cpu = get_physical_cpu();
    gator_timer_online_dispatch(cpu, true);
    gator_timer_online((void *)1);
}

GATOR_DEFINE_PROBE(cpu_migrate_current, TP_PROTO(u64 timestamp, u32 cpu_hwid))
{
    gator_update_cpu_mapping(cpu_hwid);
}

static void gator_send_iks_core_names(void)
{
    int cpu;
    /* Send the cpu names */
    preempt_disable();
    for (cpu = 0; cpu < nr_cpu_ids; ++cpu) {
        if (mpidr_cpus[cpu] != NULL)
            gator_send_core_name(cpu, mpidr_cpus[cpu]->cpuid);
    }
    preempt_enable();
}

static int gator_migrate_start(void)
{
    int retval = 0;

    if (!map_cpuids)
        return retval;

    if (retval == 0)
        retval = GATOR_REGISTER_TRACE(cpu_migrate_begin);
    if (retval == 0)
        retval = GATOR_REGISTER_TRACE(cpu_migrate_finish);
    if (retval == 0)
        retval = GATOR_REGISTER_TRACE(cpu_migrate_current);
    if (retval == 0) {
        /* Initialize the logical to physical cpu mapping */
        memset(&__lcpu_to_pcpu, 0xff, sizeof(__lcpu_to_pcpu));
        bL_switcher_trace_trigger();
    }
    return retval;
}

static void gator_migrate_stop(void)
{
    if (!map_cpuids)
        return;

    GATOR_UNREGISTER_TRACE(cpu_migrate_current);
    GATOR_UNREGISTER_TRACE(cpu_migrate_finish);
    GATOR_UNREGISTER_TRACE(cpu_migrate_begin);
}

#else

#define calc_first_cluster_size()
#define gator_send_iks_core_names()
#define gator_migrate_start() 0
#define gator_migrate_stop()

#endif