virtio-net.h

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#ifndef _VIRTIO_NET_H
#define _VIRTIO_NET_H
 
/** @file
 *
 * Virtual I/O network device
 *
 */
 
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
FILE_SECBOOT ( PERMITTED );
 
#include <ipxe/virtio.h>
 
/** Device has a reported MTU */
#define VIRTIO_FEAT0_NET_MTU 0x00000008
 
/** Device has a MAC address */
#define VIRTIO_FEAT0_NET_MAC 0x00000020
 
/** MAC address register offset */
#define VIRTIO_NET_MAC 0x00
 
/** MTU register offset */
#define VIRTIO_NET_MTU 0x0a
 
/** A virtio network packet header */
union virtio_net_header {
        /** Legacy interface */
        uint8_t legacy[10];
        /** Modern (version 1.0) interface */
        uint8_t modern[12];
} __attribute__ (( packed ));
 
/** Receive queue index */
#define VIRTIO_NET_RX_INDEX 0
 
/** Receive queue requested queue size */
#define VIRTIO_NET_RX_COUNT 128
 
/** Receive queue maximum fill level */
#define VIRTIO_NET_RX_MAX 16
 
/** Transmit queue index */
#define VIRTIO_NET_TX_INDEX 1
 
/** Transmit queue requested queue size */
#define VIRTIO_NET_TX_COUNT 128
 
/** Transmit queue maximum fill level */
#define VIRTIO_NET_TX_MAX 128
 
/** Number of descriptors per packet */
#define VIRTIO_NET_DESCS 2
 
/** A virtio network queue */
struct virtio_net_queue {
        /** Underlying virtio queue */
        struct virtio_queue queue;
        /** I/O buffer list */
        struct io_buffer **iobufs;
        /** Descriptor slot ring */
        uint8_t *slots;
        /** Effective fill level */
        unsigned int fill;
        /** Descriptor index ring mask */
        unsigned int mask;
 
        /** Shared packet header */
        union virtio_net_header hdr;
        /** DMA mapping for packet header */
        struct dma_mapping map;
 
        /** DMA direction for packet header */
        uint8_t dma;
        /** Buffer writability flag for packet header */
        uint8_t write;
        /** Requested queue size */
        uint8_t count;
        /** Maximum fill level */
        uint8_t max;
};
 
/**
 * Initialise virtio network queue
 *
 * @v queue             Virtio network queue
 * @v index             Queue index
 * @v iobufs            I/O buffer list
 * @v slots             Descriptor slot ring
 * @v dma               DMA direction for packet header
 * @v write             Writability flag for packet header
 * @v count             Requested queue size
 * @v max               Maximum fill level
 */
static inline __attribute__ (( always_inline )) void
virtio_net_queue_init ( struct virtio_net_queue *queue,
                        struct io_buffer **iobufs, uint8_t *slots,
                        unsigned int index, unsigned int count,
                        unsigned int max, unsigned int dma,
                        unsigned int write ) {
 
        queue->queue.index = index;
        queue->iobufs = iobufs;
        queue->slots = slots;
        queue->dma = dma;
        queue->write = write;
        queue->count = count;
        queue->max = max;
}
 
/** A virtio network device */
struct virtio_net {
        /** Underlying virtio device */
        struct virtio_device virtio;
        /** Receive queue */
        struct virtio_net_queue rx;
        /** Transmit queue */
        struct virtio_net_queue tx;
 
        /** Virtio network header length */
        size_t hlen;
        /** Maximum frame size */
        size_t mfs;
 
        /** Receive descriptor slot ring */
        uint8_t rx_slots[VIRTIO_NET_RX_MAX];
        /** Receive I/O buffers */
        struct io_buffer *rx_iobufs[VIRTIO_NET_RX_MAX];
 
        /** Transmit descriptor slot ring */
        uint8_t tx_slots[VIRTIO_NET_TX_MAX];
        /** Transmit I/O buffers */
        struct io_buffer *tx_iobufs[VIRTIO_NET_TX_MAX];
};
 
#endif /* _VIRTIO_NET_H */