/*
 * This file is subject to the terms and conditions of the GNU General
 * Public License.  See the file "COPYING" in the main directory of this
 * archive for more details.
 *
 * Copyright (C) 2000 - 2001 by Kanoj Sarcar (kanoj@sgi.com)
 * Copyright (C) 2000 - 2001 by Silicon Graphics, Inc.
 */
#include <linux/init.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/topology.h>
#include <linux/nodemask.h>

#include <asm/page.h>
#include <asm/processor.h>
#include <asm/ptrace.h>
#include <asm/sn/agent.h>
#include <asm/sn/arch.h>
#include <asm/sn/gda.h>
#include <asm/sn/intr.h>
#include <asm/sn/klconfig.h>
#include <asm/sn/launch.h>
#include <asm/sn/mapped_kernel.h>
#include <asm/sn/types.h>

#include "ip27-common.h"

static int node_scan_cpus(nasid_t nasid, int highest)
{
        static int cpus_found;
        lboard_t *brd;
        klcpu_t *acpu;
        cpuid_t cpuid;

        brd = find_lboard((lboard_t *)KL_CONFIG_INFO(nasid), KLTYPE_IP27);

        do {
                acpu = (klcpu_t *)find_first_component(brd, KLSTRUCT_CPU);
                while (acpu) {
                        cpuid = acpu->cpu_info.virtid;
                        /* Only let it join in if it's marked enabled */
                        if ((acpu->cpu_info.flags & KLINFO_ENABLE) &&
                            (cpus_found != NR_CPUS)) {
                                if (cpuid > highest)
                                        highest = cpuid;
                                set_cpu_possible(cpuid, true);
                                cputonasid(cpus_found) = nasid;
                                cputoslice(cpus_found) = acpu->cpu_info.physid;
                                sn_cpu_info[cpus_found].p_speed =
                                                        acpu->cpu_speed;
                                cpus_found++;
                        }
                        acpu = (klcpu_t *)find_component(brd, (klinfo_t *)acpu,
                                                                KLSTRUCT_CPU);
                }
                brd = KLCF_NEXT(brd);
                if (!brd)
                        break;

                brd = find_lboard(brd, KLTYPE_IP27);
        } while (brd);

        return highest;
}

void cpu_node_probe(void)
{
        int i, highest = 0;
        gda_t *gdap = GDA;

        nodes_clear(node_online_map);
        nodes_clear(node_possible_map);
        for (i = 0; i < MAX_NUMNODES; i++) {
                nasid_t nasid = gdap->g_nasidtable[i];
                if (nasid == INVALID_NASID)
                        break;
                node_set_online(nasid);
                node_set(nasid, node_possible_map);
                highest = node_scan_cpus(nasid, highest);
        }

        printk("Discovered %d cpus on %d nodes\n", highest + 1, num_online_nodes());
}

static __init void intr_clear_all(nasid_t nasid)
{
        int i;

        REMOTE_HUB_S(nasid, PI_INT_MASK0_A, 0);
        REMOTE_HUB_S(nasid, PI_INT_MASK0_B, 0);
        REMOTE_HUB_S(nasid, PI_INT_MASK1_A, 0);
        REMOTE_HUB_S(nasid, PI_INT_MASK1_B, 0);

        for (i = 0; i < 128; i++)
                REMOTE_HUB_CLR_INTR(nasid, i);
}

static void ip27_send_ipi_single(int destid, unsigned int action)
{
        int irq;

        switch (action) {
        case SMP_RESCHEDULE_YOURSELF:
                irq = CPU_RESCHED_A_IRQ;
                break;
        case SMP_CALL_FUNCTION:
                irq = CPU_CALL_A_IRQ;
                break;
        default:
                panic("sendintr");
        }

        irq += cputoslice(destid);

        /*
         * Set the interrupt bit associated with the CPU we want to
         * send the interrupt to.
         */
        REMOTE_HUB_SEND_INTR(cpu_to_node(destid), irq);
}

static void ip27_send_ipi_mask(const struct cpumask *mask, unsigned int action)
{
        unsigned int i;

        for_each_cpu(i, mask)
                ip27_send_ipi_single(i, action);
}

static void ip27_init_cpu(void)
{
        per_cpu_init();
}

static void ip27_smp_finish(void)
{
        hub_rt_clock_event_init();
        local_irq_enable();
}

/*
 * Launch a slave into smp_bootstrap().  It doesn't take an argument, and we
 * set sp to the kernel stack of the newly created idle process, gp to the proc
 * struct so that current_thread_info() will work.
 */
static int ip27_boot_secondary(int cpu, struct task_struct *idle)
{
        unsigned long gp = (unsigned long)task_thread_info(idle);
        unsigned long sp = __KSTK_TOS(idle);

        LAUNCH_SLAVE(cputonasid(cpu), cputoslice(cpu),
                (launch_proc_t)MAPPED_KERN_RW_TO_K0(smp_bootstrap),
                0, (void *) sp, (void *) gp);
        return 0;
}

static void __init ip27_smp_setup(void)
{
        nasid_t nasid;

        for_each_online_node(nasid) {
                if (nasid == 0)
                        continue;
                intr_clear_all(nasid);
        }

        replicate_kernel_text();

        /*
         * PROM sets up system, that boot cpu is always first CPU on nasid 0
         */
        cputonasid(0) = 0;
        cputoslice(0) = LOCAL_HUB_L(PI_CPU_NUM);
}

static void __init ip27_prepare_cpus(unsigned int max_cpus)
{
        /* We already did everything necessary earlier */
}

const struct plat_smp_ops ip27_smp_ops = {
        .send_ipi_single        = ip27_send_ipi_single,
        .send_ipi_mask          = ip27_send_ipi_mask,
        .init_secondary         = ip27_init_cpu,
        .smp_finish             = ip27_smp_finish,
        .boot_secondary         = ip27_boot_secondary,
        .smp_setup              = ip27_smp_setup,
        .prepare_cpus           = ip27_prepare_cpus,
        .prepare_boot_cpu       = ip27_init_cpu,
};