/* $NetBSD: psci.c,v 1.9 2026/05/15 22:44:58 jmcneill Exp $ */

/*-
 * Copyright (c) 2017-2026 Jared McNeill <jmcneill@invisible.ca>
 * All rights reserved.
 *
 * 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 ``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 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/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: psci.c,v 1.9 2026/05/15 22:44:58 jmcneill Exp $");

#include <sys/param.h>
#include <sys/bus.h>
#include <sys/cpu.h>
#include <sys/device.h>
#include <sys/xcall.h>

#include <arm/arm/psci.h>

/* PSCI methods */
#define PSCI_VERSION            0x84000000
#define PSCI_CPU_OFF            0x84000002
#define PSCI_SYSTEM_OFF         0x84000008
#define PSCI_SYSTEM_RESET       0x84000009
#define PSCI_FEATURES           0x8400000a

#if defined(__aarch64__)
#define PSCI_CPU_SUSPEND        0xc4000001
#define PSCI_CPU_ON             0xc4000003
#define PSCI_AFFINITY_INFO      0xc4000004
#else
#define PSCI_CPU_SUSPEND        0x84000001
#define PSCI_CPU_ON             0x84000003
#define PSCI_AFFINITY_INFO      0x84000004
#endif

static psci_fn psci_call_fn;

static uint32_t psci_functions[PSCI_FUNC_MAX] = {
        [PSCI_FUNC_VERSION] = PSCI_VERSION,
        [PSCI_FUNC_SYSTEM_OFF] = PSCI_SYSTEM_OFF,
        [PSCI_FUNC_SYSTEM_RESET] = PSCI_SYSTEM_RESET,
        [PSCI_FUNC_CPU_SUSPEND] = PSCI_CPU_SUSPEND,
        [PSCI_FUNC_CPU_ON] = PSCI_CPU_ON,
        [PSCI_FUNC_CPU_OFF] = PSCI_CPU_OFF,
        [PSCI_FUNC_AFFINITY_INFO] = PSCI_AFFINITY_INFO,
        [PSCI_FUNC_FEATURES] = PSCI_FEATURES,
};

int
psci_call(register_t fid, register_t arg1, register_t arg2, register_t arg3)
{
        KASSERT(psci_call_fn != NULL);

        if (fid == 0)
                return PSCI_NOT_SUPPORTED;

        return psci_call_fn(fid, arg1, arg2, arg3);
}

enum psci_conduit
psci_conduit(void)
{
        if (psci_call_fn == psci_call_smc) {
                return PSCI_CONDUIT_SMC;
        } else if (psci_call_fn == psci_call_hvc) {
                return PSCI_CONDUIT_HVC;
        } else {
                return PSCI_CONDUIT_NONE;
        }
}

uint32_t
psci_version(void)
{
        if (psci_functions[PSCI_FUNC_VERSION] == 0) {
                /* Pre-0.2 implementation */
                return __SHIFTIN(0, PSCI_VERSION_MAJOR) |
                       __SHIFTIN(1, PSCI_VERSION_MINOR);
        }

        return psci_call(psci_functions[PSCI_FUNC_VERSION], 0, 0, 0);
}

int
psci_cpu_on(register_t target_cpu, register_t entry_point_address,
    register_t context_id)
{
        return psci_call(psci_functions[PSCI_FUNC_CPU_ON], target_cpu,
            entry_point_address, context_id);
}

int
psci_cpu_off(void)
{
        return psci_call(psci_functions[PSCI_FUNC_CPU_OFF], 0, 0, 0);
}

int
psci_cpu_suspend(uint32_t power_state)
{
        return psci_call(psci_functions[PSCI_FUNC_CPU_SUSPEND], power_state,
            0, 0);
}

int
psci_affinity_info(uint64_t target_affinity, uint32_t lowest_affinity_level)
{
        return psci_call(psci_functions[PSCI_FUNC_AFFINITY_INFO],
            target_affinity, lowest_affinity_level, 0);
}


void
psci_system_off(void)
{
        psci_call(psci_functions[PSCI_FUNC_SYSTEM_OFF], 0, 0, 0);
}

void
psci_system_reset(void)
{
        psci_call(psci_functions[PSCI_FUNC_SYSTEM_RESET], 0, 0, 0);
}

int
psci_features(uint32_t fid)
{
        if (psci_functions[PSCI_FUNC_FEATURES] == 0) {
                return PSCI_NOT_SUPPORTED;
        }
        return psci_call(psci_functions[PSCI_FUNC_FEATURES], fid, 0, 0);
}

void
psci_init(psci_fn fn)
{
        psci_call_fn = fn;
}

bool
psci_available(void)
{
        return psci_call_fn != NULL;
}

void
psci_clearfunc(void)
{
        for (int i = 0; i < PSCI_FUNC_MAX; i++)
                psci_setfunc(i, 0);
}

void
psci_setfunc(enum psci_function func, uint32_t fid)
{
        psci_functions[func] = fid;
}

static void
psci_cpu_off_xcall(void *arg1, void *arg2)
{
        if (curcpu() != arg1) {
                aprint_debug("%s: power down\n", cpu_name(curcpu()));
                psci_cpu_off();
                printf("WARNING: %s power down failed\n", cpu_name(curcpu()));
        }
}

void
psci_poweroff(void)
{
        if (ncpuonline > 1) {
                CPU_INFO_ITERATOR cii;
                struct cpu_info *ci;
                int ret;

                /* Call PSCI_CPU_OFF on all CPUs except for ourselves. */
                xc_broadcast(0, psci_cpu_off_xcall, curcpu(), NULL);

                /* Wait for all CPUs to enter OFF state. */
                for (CPU_INFO_FOREACH(cii, ci)) {
                        if (ci == curcpu()) {
                                continue;
                        }
                        for (;;) {
                                ret = psci_affinity_info(ci->ci_cpuid, 0);
                                if (ret < 0) {
                                        printf("WARNING: %s state %d\n",
                                            cpu_name(ci), ret);
                                }
                                if (ret != PSCI_AFFINITY_INFO_ON) {
                                        break;
                                }
                        }
                }
        }

        /* Power off the system. */
        psci_system_off();
}