ZXFoundation/svc_8cxxm_source.html

/// SPDX-License-Identifier: Apache-2.0

/// @file svc.cxxm

/// @brief Centralized SVC dispatch.


export module arch.s390x.trap.svc;

import arch.s390x.cpu.lowcore;

import arch.s390x.cpu.irq;

import zxfoundation.dgp.gate.types;

import zxfoundation.dgp.gate.dispatch;

import zxfoundation.dgp.domain.types;

import zxfoundation.dgp.domain.types;

import zxfoundation.base.types;

import zxfoundation.base.typestate;


export {


namespace arch::s390x::trap::svc {


    using zxfoundation::dgp::gate::call_namespace;

    using zxfoundation::dgp::gate::sys_op;

    using zxfoundation::dgp::gate::dispatch::dispatch;

    using zxfoundation::base::lifecycle_state;


    /// @brief Centralized SVC nucleus-call dispatcher.


    [[nodiscard]] auto handle(cpu::irq::irq_frame* frame, const u16 svc_code) noexcept -> u64 {

        const u32 packed_nr = svc_code;

        const u64 a0 = frame->gprs[2];

        const u64 a1 = frame->gprs[3];

        const u64 a2 = frame->gprs[4];

        const u64 a3 = frame->gprs[5];

        const u64 a4 = frame->gprs[6];


        const auto* lc = cpu::lowcore::get_current();

        if (const auto* d  = lc ? reinterpret_cast<zxfoundation::dgp::domain::domain*>(lc->current_domain) : nullptr;

            !d || d->ko.state != lifecycle_state::active) {

            return ~0ULL;

        }


        const u64 result = dispatch(packed_nr, a0, a1, a2, a3, a4);

        const u32 shm_import = zxfoundation::dgp::gate::pack_call(

            call_namespace::sys, static_cast<u32>(sys_op::shm_import));

        const u32 shm_map = zxfoundation::dgp::gate::pack_call(

            call_namespace::sys, static_cast<u32>(sys_op::shm_map));

        if ((packed_nr == shm_import || packed_nr == shm_map) && result < 16U) {

            auto* strand = reinterpret_cast<zxfoundation::dgp::domain::strand*>(

                lc->percpu.current_strand);

            if (strand && strand->body) {

                frame->access_regs[result] = strand->body->uregs.access_regs[result];

            }

        }

        return result;

    }


} // namespace arch::s390x::trap::svc


} // end export