smp.c

Go to the documentation of this file.

/*
 * Copyright 2003-2011 NetLogic Microsystems, Inc. (NetLogic). All rights
 * reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the NetLogic
 * license below:
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY NETLOGIC ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL NETLOGIC OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <linux/irq.h>

#include <asm/mmu_context.h>

#include <asm/netlogic/interrupt.h>
#include <asm/netlogic/mips-extns.h>
#include <asm/netlogic/haldefs.h>
#include <asm/netlogic/common.h>

#if defined(CONFIG_CPU_XLP)
#include <asm/netlogic/xlp-hal/iomap.h>
#include <asm/netlogic/xlp-hal/xlp.h>
#include <asm/netlogic/xlp-hal/pic.h>
#elif defined(CONFIG_CPU_XLR)
#include <asm/netlogic/xlr/iomap.h>
#include <asm/netlogic/xlr/pic.h>
#include <asm/netlogic/xlr/xlr.h>
#else
#error "Unknown CPU"
#endif

void nlm_send_ipi_single(int logical_cpu, unsigned int action)
{
    int cpu = cpu_logical_map(logical_cpu);

    if (action & SMP_CALL_FUNCTION)
        nlm_pic_send_ipi(nlm_pic_base, cpu, IRQ_IPI_SMP_FUNCTION, 0);
    if (action & SMP_RESCHEDULE_YOURSELF)
        nlm_pic_send_ipi(nlm_pic_base, cpu, IRQ_IPI_SMP_RESCHEDULE, 0);
}

void nlm_send_ipi_mask(const struct cpumask *mask, unsigned int action)
{
    int cpu;

    for_each_cpu(cpu, mask) {
        nlm_send_ipi_single(cpu, action);
    }
}

/* IRQ_IPI_SMP_FUNCTION Handler */
void nlm_smp_function_ipi_handler(unsigned int irq, struct irq_desc *desc)
{
    write_c0_eirr(1ull << irq);
    smp_call_function_interrupt();
}

/* IRQ_IPI_SMP_RESCHEDULE  handler */
void nlm_smp_resched_ipi_handler(unsigned int irq, struct irq_desc *desc)
{
    write_c0_eirr(1ull << irq);
    scheduler_ipi();
}

/*
 * Called before going into mips code, early cpu init
 */
void nlm_early_init_secondary(int cpu)
{
    change_c0_config(CONF_CM_CMASK, 0x3);
    write_c0_ebase((uint32_t)nlm_common_ebase);
#ifdef CONFIG_CPU_XLP
    if (hard_smp_processor_id() % 4 == 0)
        xlp_mmu_init();
#endif
}

/*
 * Code to run on secondary just after probing the CPU
 */
static void __cpuinit nlm_init_secondary(void)
{
    current_cpu_data.core = hard_smp_processor_id() / 4;
    nlm_smp_irq_init();
}

void nlm_prepare_cpus(unsigned int max_cpus)
{
    /* declare we are SMT capable */
    smp_num_siblings = nlm_threads_per_core;
}

void nlm_smp_finish(void)
{
#ifdef notyet
    nlm_common_msgring_cpu_init();
#endif
    local_irq_enable();
}

void nlm_cpus_done(void)
{
}

/*
 * Boot all other cpus in the system, initialize them, and bring them into
 * the boot function
 */
int nlm_cpu_ready[NR_CPUS];
unsigned long nlm_next_gp;
unsigned long nlm_next_sp;

cpumask_t phys_cpu_present_map;

void nlm_boot_secondary(int logical_cpu, struct task_struct *idle)
{
    unsigned long gp = (unsigned long)task_thread_info(idle);
    unsigned long sp = (unsigned long)__KSTK_TOS(idle);
    int cpu = cpu_logical_map(logical_cpu);

    nlm_next_sp = sp;
    nlm_next_gp = gp;

    /* barrier */
    __sync();
    nlm_pic_send_ipi(nlm_pic_base, cpu, 1, 1);
}

void __init nlm_smp_setup(void)
{
    unsigned int boot_cpu;
    int num_cpus, i;

    boot_cpu = hard_smp_processor_id();
    cpus_clear(phys_cpu_present_map);

    cpu_set(boot_cpu, phys_cpu_present_map);
    __cpu_number_map[boot_cpu] = 0;
    __cpu_logical_map[0] = boot_cpu;
    set_cpu_possible(0, true);

    num_cpus = 1;
    for (i = 0; i < NR_CPUS; i++) {
        /*
         * nlm_cpu_ready array is not set for the boot_cpu,
         * it is only set for ASPs (see smpboot.S)
         */
        if (nlm_cpu_ready[i]) {
            cpu_set(i, phys_cpu_present_map);
            __cpu_number_map[i] = num_cpus;
            __cpu_logical_map[num_cpus] = i;
            set_cpu_possible(num_cpus, true);
            ++num_cpus;
        }
    }

    pr_info("Phys CPU present map: %lx, possible map %lx\n",
        (unsigned long)phys_cpu_present_map.bits[0],
        (unsigned long)cpumask_bits(cpu_possible_mask)[0]);

    pr_info("Detected %i Slave CPU(s)\n", num_cpus);
    nlm_set_nmi_handler(nlm_boot_secondary_cpus);
}

static int nlm_parse_cpumask(u32 cpu_mask)
{
    uint32_t core0_thr_mask, core_thr_mask;
    int threadmode, i;

    core0_thr_mask = cpu_mask & 0xf;
    switch (core0_thr_mask) {
    case 1:
        nlm_threads_per_core = 1;
        threadmode = 0;
        break;
    case 3:
        nlm_threads_per_core = 2;
        threadmode = 2;
        break;
    case 0xf:
        nlm_threads_per_core = 4;
        threadmode = 3;
        break;
    default:
        goto unsupp;
    }

    /* Verify other cores CPU masks */
    nlm_coremask = 1;
    nlm_cpumask = core0_thr_mask;
    for (i = 1; i < 8; i++) {
        core_thr_mask = (cpu_mask >> (i * 4)) & 0xf;
        if (core_thr_mask) {
            if (core_thr_mask != core0_thr_mask)
                goto unsupp;
            nlm_coremask |= 1 << i;
            nlm_cpumask |= core0_thr_mask << (4 * i);
        }
    }
    return threadmode;

unsupp:
    panic("Unsupported CPU mask %x\n", cpu_mask);
    return 0;
}

int __cpuinit nlm_wakeup_secondary_cpus(u32 wakeup_mask)
{
    unsigned long reset_vec;
    char *reset_data;
    int threadmode;

    /* Update reset entry point with CPU init code */
    reset_vec = CKSEG1ADDR(RESET_VEC_PHYS);
    memcpy((void *)reset_vec, (void *)nlm_reset_entry,
            (nlm_reset_entry_end - nlm_reset_entry));

    /* verify the mask and setup core config variables */
    threadmode = nlm_parse_cpumask(wakeup_mask);

    /* Setup CPU init parameters */
    reset_data = (char *)CKSEG1ADDR(RESET_DATA_PHYS);
    *(int *)(reset_data + BOOT_THREAD_MODE) = threadmode;

#ifdef CONFIG_CPU_XLP
    xlp_wakeup_secondary_cpus();
#else
    xlr_wakeup_secondary_cpus();
#endif
    return 0;
}

struct plat_smp_ops nlm_smp_ops = {
    .send_ipi_single    = nlm_send_ipi_single,
    .send_ipi_mask      = nlm_send_ipi_mask,
    .init_secondary     = nlm_init_secondary,
    .smp_finish     = nlm_smp_finish,
    .cpus_done      = nlm_cpus_done,
    .boot_secondary     = nlm_boot_secondary,
    .smp_setup      = nlm_smp_setup,
    .prepare_cpus       = nlm_prepare_cpus,
};