/*-
 * Copyright (C) 2009 Nathan Whitehorn
 * Copyright (C) 2015 The FreeBSD Foundation
 * All rights reserved.
 *
 * Portions of this software were developed by Andrew Turner
 * under sponsorship from the FreeBSD Foundation.
 *
 * 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 THE AUTHOR AND CONTRIBUTORS ``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 THE AUTHOR 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 <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/module.h>
#include <sys/malloc.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/smp.h>
#include <machine/bus.h>

#include <dev/ofw/openfirm.h>
#include <dev/ofw/ofw_bus.h>
#include <dev/ofw/ofw_bus_subr.h>
#include <dev/ofw/ofw_cpu.h>

#if defined(__arm__) || defined(__aarch64__) || defined(__riscv)
#include <dev/clk/clk.h>
#define HAS_CLK
#endif

static int      ofw_cpulist_probe(device_t);
static int      ofw_cpulist_attach(device_t);
static const struct ofw_bus_devinfo *ofw_cpulist_get_devinfo(device_t dev,
    device_t child);

static MALLOC_DEFINE(M_OFWCPU, "ofwcpu", "OFW CPU device information");

struct ofw_cpulist_softc {
        pcell_t  sc_addr_cells;
};

static device_method_t ofw_cpulist_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         ofw_cpulist_probe),
        DEVMETHOD(device_attach,        ofw_cpulist_attach),

        /* Bus interface */
        DEVMETHOD(bus_add_child,        bus_generic_add_child),
        DEVMETHOD(bus_child_pnpinfo,    ofw_bus_gen_child_pnpinfo),
        DEVMETHOD(bus_get_device_path,  ofw_bus_gen_get_device_path),

        /* ofw_bus interface */
        DEVMETHOD(ofw_bus_get_devinfo,  ofw_cpulist_get_devinfo),
        DEVMETHOD(ofw_bus_get_compat,   ofw_bus_gen_get_compat),
        DEVMETHOD(ofw_bus_get_model,    ofw_bus_gen_get_model),
        DEVMETHOD(ofw_bus_get_name,     ofw_bus_gen_get_name),
        DEVMETHOD(ofw_bus_get_node,     ofw_bus_gen_get_node),
        DEVMETHOD(ofw_bus_get_type,     ofw_bus_gen_get_type),

        DEVMETHOD_END
};

static driver_t ofw_cpulist_driver = {
        "cpulist",
        ofw_cpulist_methods,
        sizeof(struct ofw_cpulist_softc)
};

EARLY_DRIVER_MODULE(ofw_cpulist, ofwbus, ofw_cpulist_driver, 0, 0,
    BUS_PASS_CPU + BUS_PASS_ORDER_MIDDLE);

static int
ofw_cpulist_probe(device_t dev)
{
        const char *name;

        name = ofw_bus_get_name(dev);

        if (name == NULL || strcmp(name, "cpus") != 0)
                return (ENXIO);

        device_set_desc(dev, "Open Firmware CPU Group");

        return (0);
}

static int
ofw_cpulist_attach(device_t dev)
{
        struct ofw_cpulist_softc *sc;
        phandle_t root, child;
        device_t cdev;
        struct ofw_bus_devinfo *dinfo;

        sc = device_get_softc(dev);
        root = ofw_bus_get_node(dev);

        sc->sc_addr_cells = 1;
        OF_getencprop(root, "#address-cells", &sc->sc_addr_cells,
            sizeof(sc->sc_addr_cells));

        for (child = OF_child(root); child != 0; child = OF_peer(child)) {
                dinfo = malloc(sizeof(*dinfo), M_OFWCPU, M_WAITOK | M_ZERO);

                if (ofw_bus_gen_setup_devinfo(dinfo, child) != 0) {
                        free(dinfo, M_OFWCPU);
                        continue;
                }
                cdev = device_add_child(dev, NULL, DEVICE_UNIT_ANY);
                if (cdev == NULL) {
                        device_printf(dev, "<%s>: device_add_child failed\n",
                            dinfo->obd_name);
                        ofw_bus_gen_destroy_devinfo(dinfo);
                        free(dinfo, M_OFWCPU);
                        continue;
                }
                device_set_ivars(cdev, dinfo);
        }

        bus_attach_children(dev);
        return (0);
}

static const struct ofw_bus_devinfo *
ofw_cpulist_get_devinfo(device_t dev, device_t child)
{
        return (device_get_ivars(child));
}

static int      ofw_cpu_probe(device_t);
static int      ofw_cpu_attach(device_t);
static int      ofw_cpu_read_ivar(device_t dev, device_t child, int index,
    uintptr_t *result);

struct ofw_cpu_softc {
        struct pcpu     *sc_cpu_pcpu;
        uint32_t         sc_nominal_mhz;
        bool             sc_reg_valid;
        pcell_t          sc_reg[2];
};

static device_method_t ofw_cpu_methods[] = {
        /* Device interface */
        DEVMETHOD(device_probe,         ofw_cpu_probe),
        DEVMETHOD(device_attach,        ofw_cpu_attach),

        /* Bus interface */
        DEVMETHOD(bus_add_child,        bus_generic_add_child),
        DEVMETHOD(bus_read_ivar,        ofw_cpu_read_ivar),
        DEVMETHOD(bus_setup_intr,       bus_generic_setup_intr),
        DEVMETHOD(bus_teardown_intr,    bus_generic_teardown_intr),
        DEVMETHOD(bus_alloc_resource,   bus_generic_alloc_resource),
        DEVMETHOD(bus_release_resource, bus_generic_release_resource),
        DEVMETHOD(bus_activate_resource,bus_generic_activate_resource),

        DEVMETHOD_END
};

static driver_t ofw_cpu_driver = {
        "cpu",
        ofw_cpu_methods,
        sizeof(struct ofw_cpu_softc)
};

EARLY_DRIVER_MODULE(ofw_cpu, cpulist, ofw_cpu_driver, 0, 0,
    BUS_PASS_CPU + BUS_PASS_ORDER_MIDDLE);

static bool
ofw_cpu_is_runnable(phandle_t node)
{
        /*
         * Per the DeviceTree Specification, a cpu node (under /cpus) that
         * has 'status = disabled' indicates that "the CPU is in a quiescent
         * state."
         *
         * A quiescent CPU that specifies an "enable-method", such as
         * "spin-table", can still be used by the kernel.
         *
         * Lacking this, any CPU marked "disabled" or other non-okay status
         * should be excluded from the kernel's view.
         */
        return (ofw_bus_node_status_okay(node) ||
            OF_hasprop(node, "enable-method"));
}

static int
ofw_cpu_probe(device_t dev)
{
        const char *type = ofw_bus_get_type(dev);

        if (type == NULL || strcmp(type, "cpu") != 0)
                return (ENXIO);

        if (!ofw_cpu_is_runnable(ofw_bus_get_node(dev)))
                return (ENXIO);

        device_set_desc(dev, "Open Firmware CPU");
        if (!bootverbose && device_get_unit(dev) != 0) {
                device_quiet(dev);
                device_quiet_children(dev);
        }

        return (0);
}

static int
get_freq_from_clk(device_t dev, struct ofw_cpu_softc *sc)
{
#ifdef HAS_CLK
        clk_t cpuclk;
        uint64_t freq;
        int rv;

        rv = clk_get_by_ofw_index(dev, 0, 0, &cpuclk);
        if (rv == 0) {
                rv = clk_get_freq(cpuclk, &freq);
                if (rv != 0 && bootverbose)
                        device_printf(dev,
                            "Cannot get freq of property clocks\n");
                else
                        sc->sc_nominal_mhz = freq / 1000000;
        }

        return (rv);
#else
        return (ENODEV);
#endif
}

static int
ofw_cpu_attach(device_t dev)
{
        struct ofw_cpulist_softc *psc;
        struct ofw_cpu_softc *sc;
        phandle_t node;
        pcell_t cell;
        int rv;

        sc = device_get_softc(dev);
        psc = device_get_softc(device_get_parent(dev));

        if (nitems(sc->sc_reg) < psc->sc_addr_cells) {
                if (bootverbose)
                        device_printf(dev, "Too many address cells\n");
                return (EINVAL);
        }

        node = ofw_bus_get_node(dev);

        /* Read and validate the reg property for use later */
        sc->sc_reg_valid = false;
        rv = OF_getencprop(node, "reg", sc->sc_reg, sizeof(sc->sc_reg));
        if (rv < 0)
                device_printf(dev, "missing 'reg' property\n");
        else if ((rv % 4) != 0) {
                if (bootverbose)
                        device_printf(dev, "Malformed reg property\n");
        } else if ((rv / 4) != psc->sc_addr_cells) {
                if (bootverbose)
                        device_printf(dev, "Invalid reg size %u\n", rv);
        } else
                sc->sc_reg_valid = true;

#ifdef __aarch64__
        if (sc->sc_reg_valid) {
                uint64_t target_mpidr;

                target_mpidr = sc->sc_reg[0];
                if (psc->sc_addr_cells > 1) {
                        MPASS(psc->sc_addr_cells == 2);
                        target_mpidr <<= 32;
                        target_mpidr |= sc->sc_reg[1];
                }
                target_mpidr &= CPU_AFF_MASK;
                for (int cpu = 0; cpu <= mp_maxid; cpu++) {
                        if (cpuid_to_pcpu[cpu] == NULL)
                                continue;

                        if (cpuid_to_pcpu[cpu]->pc_mpidr == target_mpidr) {
                                sc->sc_cpu_pcpu = cpuid_to_pcpu[cpu];
                                break;
                        }
                }
        }
#endif
#ifdef __powerpc__
        /*
         * On powerpc, "interrupt-servers" denotes a SMT CPU.  Look for any
         * thread on this CPU, and assign that.
         */
        if (OF_hasprop(node, "ibm,ppc-interrupt-server#s")) {
                struct cpuref cpuref;
                cell_t *servers;
                int i, nservers, rv;

                if ((nservers = OF_getencprop_alloc(node,
                    "ibm,ppc-interrupt-server#s", (void **)&servers)) < 0)
                        return (ENXIO);
                nservers /= sizeof(cell_t);
                for (i = 0; i < nservers; i++) {
                        for (rv = platform_smp_first_cpu(&cpuref); rv == 0;
                            rv = platform_smp_next_cpu(&cpuref)) {
                                if (cpuref.cr_hwref == servers[i]) {
                                        sc->sc_cpu_pcpu =
                                            pcpu_find(cpuref.cr_cpuid);
                                        if (sc->sc_cpu_pcpu == NULL) {
                                                OF_prop_free(servers);
                                                return (ENXIO);
                                        }
                                        break;
                                }
                        }
                        if (rv != ENOENT)
                                break;
                }
                OF_prop_free(servers);
                if (sc->sc_cpu_pcpu == NULL) {
                        device_printf(dev, "No CPU found for this device.\n");
                        return (ENXIO);
                }
        }
#endif
        if (sc->sc_cpu_pcpu == NULL)
                sc->sc_cpu_pcpu = pcpu_find(device_get_unit(dev));

#ifdef HAS_CLK
        clk_set_assigned(dev, node);
        if (!OF_hasprop(node, "clocks")) {
#endif

        if (OF_getencprop(node, "clock-frequency", &cell, sizeof(cell)) < 0) {
                if (get_freq_from_clk(dev, sc) != 0) {
                        if (bootverbose)
                                device_printf(dev,
                                    "missing 'clock-frequency' property\n");
                }
        } else
                sc->sc_nominal_mhz = cell / 1000000; /* convert to MHz */

        if (sc->sc_nominal_mhz != 0 && bootverbose)
                device_printf(dev, "Nominal frequency %dMhz\n",
                    sc->sc_nominal_mhz);

        OF_device_register_xref(OF_xref_from_node(node), dev);

#ifdef HAS_CLK
        }
#endif
        bus_identify_children(dev);
        bus_attach_children(dev);
        return (0);
}

static int
ofw_cpu_read_ivar(device_t dev, device_t child, int index, uintptr_t *result)
{
        struct ofw_cpulist_softc *psc;
        struct ofw_cpu_softc *sc;

        sc = device_get_softc(dev);

        switch (index) {
        case CPU_IVAR_PCPU:
                *result = (uintptr_t)sc->sc_cpu_pcpu;
                return (0);
        case CPU_IVAR_NOMINAL_MHZ:
                if (sc->sc_nominal_mhz > 0) {
                        *result = (uintptr_t)sc->sc_nominal_mhz;
                        return (0);
                }
                break;
        case CPU_IVAR_CPUID_SIZE:
                psc = device_get_softc(device_get_parent(dev));
                *result = psc->sc_addr_cells;
                return (0);
        case CPU_IVAR_CPUID:
                if (sc->sc_reg_valid) {
                        *result = (uintptr_t)sc->sc_reg;
                        return (0);
                }
                break;
        }

        return (ENOENT);
}

int
ofw_cpu_early_foreach(ofw_cpu_foreach_cb callback, bool only_runnable)
{
        phandle_t node, child;
        pcell_t addr_cells, reg[2];
        char device_type[16];
        u_int id, next_id;
        int count, rv;

        count = 0;
        id = 0;
        next_id = 0;

        node = OF_finddevice("/cpus");
        if (node == -1)
                return (-1);

        /* Find the number of cells in the cpu register */
        if (OF_getencprop(node, "#address-cells", &addr_cells,
            sizeof(addr_cells)) < 0)
                return (-1);

        for (child = OF_child(node); child != 0; child = OF_peer(child),
            id = next_id) {
                /* Check if child is a CPU */
                memset(device_type, 0, sizeof(device_type));
                rv = OF_getprop(child, "device_type", device_type,
                    sizeof(device_type) - 1);
                if (rv < 0)
                        continue;
                if (strcmp(device_type, "cpu") != 0)
                        continue;

                /* We're processing CPU, update next_id used in the next iteration */
                next_id++;

                /*
                 * If we are filtering by runnable then limit to only
                 * those that have been enabled, or do provide a method
                 * to enable them.
                 */
                if (only_runnable && !ofw_cpu_is_runnable(child))
                        continue;

                /*
                 * Check we have a register to identify the cpu
                 */
                rv = OF_getencprop(child, "reg", reg,
                    addr_cells * sizeof(cell_t));
                if (rv != addr_cells * sizeof(cell_t))
                        continue;

                if (callback == NULL || callback(id, child, addr_cells, reg))
                        count++;
        }

        return (only_runnable ? count : id);
}