/*
 * Copyright 2014, General Dynamics C4 Systems
 *
 * This software may be distributed and modified according to the terms of
 * the GNU General Public License version 2. Note that NO WARRANTY is provided.
 * See "LICENSE_GPLv2.txt" for details.
 *
 * @TAG(GD_GPL)
 */

#include <types.h>
#include <api/failures.h>

#include <arch/object/interrupt.h>

static exception_t
Arch_invokeIRQControl(irq_t irq, cte_t *handlerSlot, cte_t *controlSlot, bool_t trigger)
{
#ifdef HAVE_SET_TRIGGER
    setIRQTrigger(irq, trigger);
#endif
    return invokeIRQControl(irq, handlerSlot, controlSlot);
}

exception_t
Arch_decodeIRQControlInvocation(word_t invLabel, word_t length,
                                cte_t *srcSlot, extra_caps_t excaps,
                                word_t *buffer)
{
    if (invLabel == ARMIRQIssueIRQHandlerTrigger) {
        if (length < 4 || excaps.excaprefs[0] == NULL) {
            current_syscall_error.type = seL4_TruncatedMessage;
            return EXCEPTION_SYSCALL_ERROR;
        }

        if (!config_set(HAVE_SET_TRIGGER)) {
            userError("This platform does not support setting the IRQ trigger");
            current_syscall_error.type = seL4_IllegalOperation;
            return EXCEPTION_SYSCALL_ERROR;
        }

        word_t irq_w = getSyscallArg(0, buffer);
        irq_t irq = (irq_t) irq_w;
        bool_t trigger = !!getSyscallArg(1, buffer);
        word_t index = getSyscallArg(2, buffer);
        word_t depth = getSyscallArg(3, buffer);

        cap_t cnodeCap = excaps.excaprefs[0]->cap;

        exception_t status = Arch_checkIRQ(irq_w);
        if (status != EXCEPTION_NONE) {
            return status;
        }

        if (isIRQActive(irq)) {
            current_syscall_error.type = seL4_RevokeFirst;
            userError("Rejecting request for IRQ %u. Already active.", (int)irq);
            return EXCEPTION_SYSCALL_ERROR;
        }

        lookupSlot_ret_t lu_ret = lookupTargetSlot(cnodeCap, index, depth);
        if (lu_ret.status != EXCEPTION_NONE) {
            userError("Target slot for new IRQ Handler cap invalid: cap %lu, IRQ %u.",
                      getExtraCPtr(buffer, 0), (int)irq);
            return lu_ret.status;
        }

        cte_t *destSlot = lu_ret.slot;

        status = ensureEmptySlot(destSlot);
        if (status != EXCEPTION_NONE) {
            userError("Target slot for new IRQ Handler cap not empty: cap %lu, IRQ %u.",
                      getExtraCPtr(buffer, 0), (int)irq);
            return status;
        }

        setThreadState(NODE_STATE(ksCurThread), ThreadState_Restart);
        return Arch_invokeIRQControl(irq, destSlot, srcSlot, trigger);
    } else {
        current_syscall_error.type = seL4_IllegalOperation;
        return EXCEPTION_SYSCALL_ERROR;
    }
}