/*- SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2016-2017,2022 Microsoft Corp.
 *
 * 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 unmodified, 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>
#include <dev/hyperv/include/hyperv.h>
#include <dev/hyperv/include/hyperv_busdma.h>
#include <dev/hyperv/vmbus/aarch64/hyperv_machdep.h>
#include <dev/hyperv/vmbus/aarch64/hyperv_reg.h>
#include <dev/hyperv/vmbus/hyperv_var.h>
#include <dev/hyperv/vmbus/hyperv_common_reg.h>
#include <dev/psci/smccc.h>

#define HVCALL_SET_VP_REGISTERS 0x0051
#define HVCALL_GET_VP_REGISTERS 0x0050
#define BIT(A) (1 << (A))
#define HV_HYPERCALL_FAST_BIT BIT(16)
#define BIT_ULL(a) (1ULL << (a))
#define HV_HYPERCALL_REP_COMP_1 BIT_ULL(32)
#define HV_PARTITION_ID_SELF ((u64)-1)
#define HV_VP_INDEX_SELF ((u32)-2)
#define HV_SMCCC_FUNC_NUMBER 1

#define HV_FUNC_ID                                           \
        SMCCC_FUNC_ID(SMCCC_YIELDING_CALL, SMCCC_64BIT_CALL, \
            SMCCC_VENDOR_HYP_SERVICE_CALLS, HV_SMCCC_FUNC_NUMBER)

void
arm_hv_set_vreg(u32 msr, u64 value)
{
        arm_smccc_invoke_hvc(HV_FUNC_ID,
            HVCALL_SET_VP_REGISTERS | HV_HYPERCALL_FAST_BIT |
                HV_HYPERCALL_REP_COMP_1,
            HV_PARTITION_ID_SELF, HV_VP_INDEX_SELF, msr, 0, value, NULL);
}

void
hv_get_vpreg_128(u32 msr, struct hv_get_vp_registers_output *result)
{
        struct arm_smccc_1_2_regs args;
        struct arm_smccc_1_2_regs res;

        args.a0 = HV_FUNC_ID;
        args.a1 = HVCALL_GET_VP_REGISTERS | HV_HYPERCALL_FAST_BIT |
            HV_HYPERCALL_REP_COMP_1;
        args.a2 = HV_PARTITION_ID_SELF;
        args.a3 = HV_VP_INDEX_SELF;
        args.a4 = msr;

        /*
         * Use the SMCCC 1.2 interface because the results are in registers
         * beyond X0-X3.
         */
        arm_smccc_1_2_hvc(&args, &res);

        result->as64.low = res.a6;
        result->as64.high = res.a7;
}

u64
arm_hv_get_vreg(u32 msr)
{
        struct hv_get_vp_registers_output output;

        hv_get_vpreg_128(msr, &output);

        return (output.as64.low);
}

uint64_t
hypercall_md(volatile void *hc_addr, uint64_t in_val, uint64_t in_paddr,
    uint64_t out_paddr)
{
        struct arm_smccc_res res;

        arm_smccc_invoke_hvc(HV_FUNC_ID, in_val, in_paddr, out_paddr, &res);

        return (res.a0);
}