source: mainline/uspace/drv/uhci/transfer_list.c@ f0e25e8

#include <errno.h>

#include "transfer_list.h"

int transfer_list_init(transfer_list_t *instance, transfer_list_t *next)
{
        assert(instance);
        instance->first = NULL;
        instance->last = NULL;
        instance->queue_head = malloc32(sizeof(queue_head_t));
        if (!instance->queue_head) {
                uhci_print_error("Failed to allocate queue head.\n");
                return ENOMEM;
        }
        instance->queue_head_pa = (uintptr_t)addr_to_phys(instance->queue_head);

        uint32_t next_pa = next ? next->queue_head_pa : 0;
        queue_head_init(instance->queue_head, next_pa);
        return EOK;
}
/*----------------------------------------------------------------------------*/
int transfer_list_append(
  transfer_list_t *instance, transfer_descriptor_t *transfer)
{
        assert(instance);
        assert(transfer);

        uint32_t pa = (uintptr_t)addr_to_phys(transfer);
        assert((pa & LINK_POINTER_ADDRESS_MASK) == pa);

        /* empty list */
        if (instance->first == NULL) {
                assert(instance->last == NULL);
                instance->first = instance->last = transfer;
        } else {
                assert(instance->last);
                instance->last->next_va = transfer;

                assert(instance->last->next & LINK_POINTER_TERMINATE_FLAG);
                instance->last->next = (pa & LINK_POINTER_ADDRESS_MASK);
                instance->last = transfer;
        }

        assert(instance->queue_head);
        if (instance->queue_head->element & LINK_POINTER_TERMINATE_FLAG) {
                instance->queue_head->element = (pa & LINK_POINTER_ADDRESS_MASK);
        }
        uhci_print_info("Successfully added transfer to the hc queue %p.\n",
          instance);
        return EOK;
}