[2/2] xilinx_axi*: Re-implemented interconnect

Re-implemented the interconnect between the Xilinx AXI ethernet and DMA
controllers. A QOM interface "stream" is created, for the two stream interfaces.

As per Edgars request, this is designed to be more generic than AXI-stream,
so in the future we may see more clients of this interface beyond AXI stream.

This is based primarily on Paolos original refactoring of the interconnect.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Peter A.G. Crosthwaite <peter.crosthwaite@petalogix.com>
---
 hw/Makefile.objs         |    1 +
 hw/petalogix_ml605_mmu.c |   24 +++++++++------
 hw/stream.c              |   23 ++++++++++++++
 hw/stream.h              |   31 +++++++++++++++++++
 hw/xilinx.h              |   22 +++++--------
 hw/xilinx_axidma.c       |   74 +++++++++++++++++++++++++--------------------
 hw/xilinx_axidma.h       |   39 ------------------------
 hw/xilinx_axienet.c      |   32 ++++++++++++-------
 8 files changed, 139 insertions(+), 107 deletions(-)
 create mode 100644 hw/stream.c
 create mode 100644 hw/stream.h
 delete mode 100644 hw/xilinx_axidma.h

On Mon, Aug 06, 2012 at 01:07:15PM +1000, Peter A. G. Crosthwaite wrote:
> Re-implemented the interconnect between the Xilinx AXI ethernet and DMA
> controllers. A QOM interface "stream" is created, for the two stream interfaces.
> 
> As per Edgars request, this is designed to be more generic than AXI-stream,
> so in the future we may see more clients of this interface beyond AXI stream.
> 
> This is based primarily on Paolos original refactoring of the interconnect.

Hi Peter,

Can we drop the axi_ prefix from stream.c?
Also the *app arg is xilinx specific but it can maybe refactored when more
users of the interface come along as those might have similar needs. A
scatter-gathering data interface might do.

Cheers,
Edgar

> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Peter A.G. Crosthwaite <peter.crosthwaite@petalogix.com>
> ---
>  hw/Makefile.objs         |    1 +
>  hw/petalogix_ml605_mmu.c |   24 +++++++++------
>  hw/stream.c              |   23 ++++++++++++++
>  hw/stream.h              |   31 +++++++++++++++++++
>  hw/xilinx.h              |   22 +++++--------
>  hw/xilinx_axidma.c       |   74 +++++++++++++++++++++++++--------------------
>  hw/xilinx_axidma.h       |   39 ------------------------
>  hw/xilinx_axienet.c      |   32 ++++++++++++-------
>  8 files changed, 139 insertions(+), 107 deletions(-)
>  create mode 100644 hw/stream.c
>  create mode 100644 hw/stream.h
>  delete mode 100644 hw/xilinx_axidma.h
> 
> diff --git a/hw/Makefile.objs b/hw/Makefile.objs
> index 8327e55..a2d537d 100644
> --- a/hw/Makefile.objs
> +++ b/hw/Makefile.objs
> @@ -65,6 +65,7 @@ hw-obj-$(CONFIG_XILINX) += xilinx_timer.o
>  hw-obj-$(CONFIG_XILINX) += xilinx_uartlite.o
>  hw-obj-$(CONFIG_XILINX_AXI) += xilinx_axidma.o
>  hw-obj-$(CONFIG_XILINX_AXI) += xilinx_axienet.o
> +hw-obj-$(CONFIG_XILINX_AXI) += stream.o
>  
>  # PCI watchdog devices
>  hw-obj-$(CONFIG_PCI) += wdt_i6300esb.o
> diff --git a/hw/petalogix_ml605_mmu.c b/hw/petalogix_ml605_mmu.c
> index 6a7d0c0..dced648 100644
> --- a/hw/petalogix_ml605_mmu.c
> +++ b/hw/petalogix_ml605_mmu.c
> @@ -39,7 +39,8 @@
>  
>  #include "microblaze_boot.h"
>  #include "microblaze_pic_cpu.h"
> -#include "xilinx_axidma.h"
> +
> +#include "stream.h"
>  
>  #define LMB_BRAM_SIZE  (128 * 1024)
>  #define FLASH_SIZE     (32 * 1024 * 1024)
> @@ -76,7 +77,7 @@ petalogix_ml605_init(ram_addr_t ram_size,
>                            const char *initrd_filename, const char *cpu_model)
>  {
>      MemoryRegion *address_space_mem = get_system_memory();
> -    DeviceState *dev;
> +    DeviceState *dev, *dma, *eth0;
>      MicroBlazeCPU *cpu;
>      CPUMBState *env;
>      DriveInfo *dinfo;
> @@ -125,15 +126,18 @@ petalogix_ml605_init(ram_addr_t ram_size,
>      /* 2 timers at irq 2 @ 100 Mhz.  */
>      xilinx_timer_create(TIMER_BASEADDR, irq[2], 0, 100 * 1000000);
>  
> -    /* axi ethernet and dma initialization. TODO: Dynamically connect them.  */
> -    {
> -        static struct XilinxDMAConnection dmach;
> +    /* axi ethernet and dma initialization. */
> +    dma = qdev_create(NULL, "xlnx.axi-dma");
>  
> -        xilinx_axiethernet_create(&dmach, &nd_table[0], 0x82780000,
> -                                  irq[3], 0x1000, 0x1000);
> -        xilinx_axiethernetdma_create(&dmach, 0x84600000,
> -                                     irq[1], irq[0], 100 * 1000000);
> -    }
> +    /* FIXME: attach to the sysbus instead */
> +    object_property_add_child(container_get(qdev_get_machine(), "/unattached"),
> +                                  "xilinx-dma", OBJECT(dma), NULL);
> +
> +    eth0 = xilinx_axiethernet_create(&nd_table[0], STREAM_SLAVE(dma),
> +                                     0x82780000, irq[3], 0x1000, 0x1000);
> +
> +    xilinx_axiethernetdma_init(dma, STREAM_SLAVE(eth0),
> +                               0x84600000, irq[1], irq[0], 100 * 1000000);
>  
>      microblaze_load_kernel(cpu, ddr_base, ram_size, BINARY_DEVICE_TREE_FILE,
>                                                              machine_cpu_reset);
> diff --git a/hw/stream.c b/hw/stream.c
> new file mode 100644
> index 0000000..001e2bd
> --- /dev/null
> +++ b/hw/stream.c
> @@ -0,0 +1,23 @@
> +#include "stream.h"
> +
> +void
> +axi_stream_push(StreamSlave *sink, uint8_t *buf, size_t len, uint32_t *app)
> +{
> +    StreamSlaveClass *k =  STREAM_SLAVE_GET_CLASS(sink);
> +
> +    k->push(sink, buf, len, app);
> +}
> +
> +static TypeInfo axi_stream_slave_info = {
> +    .name          = TYPE_STREAM_SLAVE,
> +    .parent        = TYPE_INTERFACE,
> +    .class_size = sizeof(StreamSlaveClass),
> +};
> +
> +
> +static void axi_stream_slave_register_types(void)
> +{
> +    type_register_static(&axi_stream_slave_info);
> +}
> +
> +type_init(axi_stream_slave_register_types)
> diff --git a/hw/stream.h b/hw/stream.h
> new file mode 100644
> index 0000000..b7f3b3e
> --- /dev/null
> +++ b/hw/stream.h
> @@ -0,0 +1,31 @@
> +#ifndef STREAM_H
> +#define STREAM_H 1
> +
> +#include "qemu-common.h"
> +#include "qemu/object.h"
> +
> +/* AXI stream slave. Used until qdev provides a generic way.  */
> +#define TYPE_STREAM_SLAVE "stream-slave"
> +
> +#define STREAM_SLAVE_CLASS(klass) \
> +     OBJECT_CLASS_CHECK(StreamSlaveClass, (klass), TYPE_STREAM_SLAVE)
> +#define STREAM_SLAVE_GET_CLASS(obj) \
> +    OBJECT_GET_CLASS(StreamSlaveClass, (obj), TYPE_STREAM_SLAVE)
> +#define STREAM_SLAVE(obj) \
> +     INTERFACE_CHECK(StreamSlave, (obj), TYPE_STREAM_SLAVE)
> +
> +typedef struct StreamSlave {
> +    Object Parent;
> +} StreamSlave;
> +
> +typedef struct StreamSlaveClass {
> +    InterfaceClass parent;
> +
> +    void (*push)(StreamSlave *obj, unsigned char *buf, size_t len,
> +                                                    uint32_t *app);
> +} StreamSlaveClass;
> +
> +void
> +axi_stream_push(StreamSlave *sink, uint8_t *buf, size_t len, uint32_t *app);
> +
> +#endif /* STREAM_H */
> diff --git a/hw/xilinx.h b/hw/xilinx.h
> index 7df21eb..556c5aa 100644
> --- a/hw/xilinx.h
> +++ b/hw/xilinx.h
> @@ -1,3 +1,4 @@
> +#include "stream.h"
>  #include "qemu-common.h"
>  #include "net.h"
>  
> @@ -49,8 +50,8 @@ xilinx_ethlite_create(NICInfo *nd, target_phys_addr_t base, qemu_irq irq,
>  }
>  
>  static inline DeviceState *
> -xilinx_axiethernet_create(void *dmach,
> -                          NICInfo *nd, target_phys_addr_t base, qemu_irq irq,
> +xilinx_axiethernet_create(NICInfo *nd, StreamSlave *peer,
> +                          target_phys_addr_t base, qemu_irq irq,
>                            int txmem, int rxmem)
>  {
>      DeviceState *dev;
> @@ -60,7 +61,7 @@ xilinx_axiethernet_create(void *dmach,
>      qdev_set_nic_properties(dev, nd);
>      qdev_prop_set_uint32(dev, "rxmem", rxmem);
>      qdev_prop_set_uint32(dev, "txmem", txmem);
> -    qdev_prop_set_ptr(dev, "dmach", dmach);
> +    object_property_set_link(OBJECT(dev), OBJECT(peer), "tx_dev", NULL);
>      qdev_init_nofail(dev);
>      sysbus_mmio_map(sysbus_from_qdev(dev), 0, base);
>      sysbus_connect_irq(sysbus_from_qdev(dev), 0, irq);
> @@ -68,21 +69,16 @@ xilinx_axiethernet_create(void *dmach,
>      return dev;
>  }
>  
> -static inline DeviceState *
> -xilinx_axiethernetdma_create(void *dmach,
> -                             target_phys_addr_t base, qemu_irq irq,
> -                             qemu_irq irq2, int freqhz)
> +static inline void
> +xilinx_axiethernetdma_init(DeviceState *dev, StreamSlave *peer,
> +                           target_phys_addr_t base, qemu_irq irq,
> +                           qemu_irq irq2, int freqhz)
>  {
> -    DeviceState *dev = NULL;
> -
> -    dev = qdev_create(NULL, "xlnx.axi-dma");
>      qdev_prop_set_uint32(dev, "freqhz", freqhz);
> -    qdev_prop_set_ptr(dev, "dmach", dmach);
> +    object_property_set_link(OBJECT(dev), OBJECT(peer), "tx_dev", NULL);
>      qdev_init_nofail(dev);
>  
>      sysbus_mmio_map(sysbus_from_qdev(dev), 0, base);
>      sysbus_connect_irq(sysbus_from_qdev(dev), 0, irq);
>      sysbus_connect_irq(sysbus_from_qdev(dev), 1, irq2);
> -
> -    return dev;
>  }
> diff --git a/hw/xilinx_axidma.c b/hw/xilinx_axidma.c
> index f4bec37..d38bf6f 100644
> --- a/hw/xilinx_axidma.c
> +++ b/hw/xilinx_axidma.c
> @@ -29,7 +29,7 @@
>  #include "qemu-log.h"
>  #include "qdev-addr.h"
>  
> -#include "xilinx_axidma.h"
> +#include "stream.h"
>  
>  #define D(x)
>  
> @@ -77,7 +77,7 @@ enum {
>      SDESC_STATUS_COMPLETE = (1 << 31)
>  };
>  
> -struct AXIStream {
> +struct Stream {
>      QEMUBH *bh;
>      ptimer_state *ptimer;
>      qemu_irq irq;
> @@ -94,9 +94,9 @@ struct XilinxAXIDMA {
>      SysBusDevice busdev;
>      MemoryRegion iomem;
>      uint32_t freqhz;
> -    void *dmach;
> +    StreamSlave *tx_dev;
>  
> -    struct AXIStream streams[2];
> +    struct Stream streams[2];
>  };
>  
>  /*
> @@ -113,27 +113,27 @@ static inline int stream_desc_eof(struct SDesc *d)
>      return d->control & SDESC_CTRL_EOF;
>  }
>  
> -static inline int stream_resetting(struct AXIStream *s)
> +static inline int stream_resetting(struct Stream *s)
>  {
>      return !!(s->regs[R_DMACR] & DMACR_RESET);
>  }
>  
> -static inline int stream_running(struct AXIStream *s)
> +static inline int stream_running(struct Stream *s)
>  {
>      return s->regs[R_DMACR] & DMACR_RUNSTOP;
>  }
>  
> -static inline int stream_halted(struct AXIStream *s)
> +static inline int stream_halted(struct Stream *s)
>  {
>      return s->regs[R_DMASR] & DMASR_HALTED;
>  }
>  
> -static inline int stream_idle(struct AXIStream *s)
> +static inline int stream_idle(struct Stream *s)
>  {
>      return !!(s->regs[R_DMASR] & DMASR_IDLE);
>  }
>  
> -static void stream_reset(struct AXIStream *s)
> +static void stream_reset(struct Stream *s)
>  {
>      s->regs[R_DMASR] = DMASR_HALTED;  /* starts up halted.  */
>      s->regs[R_DMACR] = 1 << 16; /* Starts with one in compl threshold.  */
> @@ -159,7 +159,7 @@ static void stream_desc_show(struct SDesc *d)
>  }
>  #endif
>  
> -static void stream_desc_load(struct AXIStream *s, target_phys_addr_t addr)
> +static void stream_desc_load(struct Stream *s, target_phys_addr_t addr)
>  {
>      struct SDesc *d = &s->desc;
>      int i;
> @@ -176,7 +176,7 @@ static void stream_desc_load(struct AXIStream *s, target_phys_addr_t addr)
>      }
>  }
>  
> -static void stream_desc_store(struct AXIStream *s, target_phys_addr_t addr)
> +static void stream_desc_store(struct Stream *s, target_phys_addr_t addr)
>  {
>      struct SDesc *d = &s->desc;
>      int i;
> @@ -192,7 +192,7 @@ static void stream_desc_store(struct AXIStream *s, target_phys_addr_t addr)
>      cpu_physical_memory_write(addr, (void *) d, sizeof *d);
>  }
>  
> -static void stream_update_irq(struct AXIStream *s)
> +static void stream_update_irq(struct Stream *s)
>  {
>      unsigned int pending, mask, irq;
>  
> @@ -204,7 +204,7 @@ static void stream_update_irq(struct AXIStream *s)
>      qemu_set_irq(s->irq, !!irq);
>  }
>  
> -static void stream_reload_complete_cnt(struct AXIStream *s)
> +static void stream_reload_complete_cnt(struct Stream *s)
>  {
>      unsigned int comp_th;
>      comp_th = (s->regs[R_DMACR] >> 16) & 0xff;
> @@ -213,14 +213,14 @@ static void stream_reload_complete_cnt(struct AXIStream *s)
>  
>  static void timer_hit(void *opaque)
>  {
> -    struct AXIStream *s = opaque;
> +    struct Stream *s = opaque;
>  
>      stream_reload_complete_cnt(s);
>      s->regs[R_DMASR] |= DMASR_DLY_IRQ;
>      stream_update_irq(s);
>  }
>  
> -static void stream_complete(struct AXIStream *s)
> +static void stream_complete(struct Stream *s)
>  {
>      unsigned int comp_delay;
>  
> @@ -240,8 +240,8 @@ static void stream_complete(struct AXIStream *s)
>      }
>  }
>  
> -static void stream_process_mem2s(struct AXIStream *s,
> -                                 struct XilinxDMAConnection *dmach)
> +static void stream_process_mem2s(struct Stream *s,
> +                                 StreamSlave *tx_dev)
>  {
>      uint32_t prev_d;
>      unsigned char txbuf[16 * 1024];
> @@ -276,7 +276,7 @@ static void stream_process_mem2s(struct AXIStream *s,
>          s->pos += txlen;
>  
>          if (stream_desc_eof(&s->desc)) {
> -            xlx_dma_push_to_client(dmach, txbuf, s->pos, app);
> +            axi_stream_push(tx_dev, txbuf, s->pos, app);
>              s->pos = 0;
>              stream_complete(s);
>          }
> @@ -295,7 +295,7 @@ static void stream_process_mem2s(struct AXIStream *s,
>      }
>  }
>  
> -static void stream_process_s2mem(struct AXIStream *s,
> +static void stream_process_s2mem(struct Stream *s,
>                                   unsigned char *buf, size_t len, uint32_t *app)
>  {
>      uint32_t prev_d;
> @@ -351,11 +351,11 @@ static void stream_process_s2mem(struct AXIStream *s,
>      }
>  }
>  
> -static
> -void axidma_push(void *opaque, unsigned char *buf, size_t len, uint32_t *app)
> +static void
> +axidma_push(StreamSlave *obj, unsigned char *buf, size_t len, uint32_t *app)
>  {
> -    struct XilinxAXIDMA *d = opaque;
> -    struct AXIStream *s = &d->streams[1];
> +    struct XilinxAXIDMA *d = FROM_SYSBUS(typeof(*d), SYS_BUS_DEVICE(obj));
> +    struct Stream *s = &d->streams[1];
>  
>      if (!app) {
>          hw_error("No stream app data!\n");
> @@ -368,7 +368,7 @@ static uint64_t axidma_read(void *opaque, target_phys_addr_t addr,
>                              unsigned size)
>  {
>      struct XilinxAXIDMA *d = opaque;
> -    struct AXIStream *s;
> +    struct Stream *s;
>      uint32_t r = 0;
>      int sid;
>  
> @@ -403,7 +403,7 @@ static void axidma_write(void *opaque, target_phys_addr_t addr,
>                           uint64_t value, unsigned size)
>  {
>      struct XilinxAXIDMA *d = opaque;
> -    struct AXIStream *s;
> +    struct Stream *s;
>      int sid;
>  
>      sid = streamid_from_addr(addr);
> @@ -440,7 +440,7 @@ static void axidma_write(void *opaque, target_phys_addr_t addr,
>              s->regs[addr] = value;
>              s->regs[R_DMASR] &= ~DMASR_IDLE; /* Not idle.  */
>              if (!sid) {
> -                stream_process_mem2s(s, d->dmach);
> +                stream_process_mem2s(s, d->tx_dev);
>              }
>              break;
>          default:
> @@ -466,12 +466,6 @@ static int xilinx_axidma_init(SysBusDevice *dev)
>      sysbus_init_irq(dev, &s->streams[0].irq);
>      sysbus_init_irq(dev, &s->streams[1].irq);
>  
> -    if (!s->dmach) {
> -        hw_error("Unconnected DMA channel.\n");
> -    }
> -
> -    xlx_dma_connect_dma(s->dmach, s, axidma_push);
> -
>      memory_region_init_io(&s->iomem, &axidma_ops, s,
>                            "xlnx.axi-dma", R_MAX * 4 * 2);
>      sysbus_init_mmio(dev, &s->iomem);
> @@ -486,9 +480,16 @@ static int xilinx_axidma_init(SysBusDevice *dev)
>      return 0;
>  }
>  
> +static void xilinx_axidma_initfn(Object *obj)
> +{
> +    struct XilinxAXIDMA *s = FROM_SYSBUS(typeof(*s), SYS_BUS_DEVICE(obj));
> +
> +    object_property_add_link(obj, "axistream-connected", TYPE_STREAM_SLAVE,
> +                             (Object **) &s->tx_dev, NULL);
> +}
> +
>  static Property axidma_properties[] = {
>      DEFINE_PROP_UINT32("freqhz", struct XilinxAXIDMA, freqhz, 50000000),
> -    DEFINE_PROP_PTR("dmach", struct XilinxAXIDMA, dmach),
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  
> @@ -496,9 +497,11 @@ static void axidma_class_init(ObjectClass *klass, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(klass);
>      SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
> +    StreamSlaveClass *ssc = STREAM_SLAVE_CLASS(klass);
>  
>      k->init = xilinx_axidma_init;
>      dc->props = axidma_properties;
> +    ssc->push = axidma_push;
>  }
>  
>  static TypeInfo axidma_info = {
> @@ -506,6 +509,11 @@ static TypeInfo axidma_info = {
>      .parent        = TYPE_SYS_BUS_DEVICE,
>      .instance_size = sizeof(struct XilinxAXIDMA),
>      .class_init    = axidma_class_init,
> +    .instance_init = xilinx_axidma_initfn,
> +    .interfaces = (InterfaceInfo[]) {
> +        { TYPE_STREAM_SLAVE },
> +        { }
> +    }
>  };
>  
>  static void xilinx_axidma_register_types(void)
> diff --git a/hw/xilinx_axidma.h b/hw/xilinx_axidma.h
> deleted file mode 100644
> index 37cb6f0..0000000
> --- a/hw/xilinx_axidma.h
> +++ /dev/null
> @@ -1,39 +0,0 @@
> -/* AXI DMA connection. Used until qdev provides a generic way.  */
> -typedef void (*DMAPushFn)(void *opaque,
> -                            unsigned char *buf, size_t len, uint32_t *app);
> -
> -struct XilinxDMAConnection {
> -    void *dma;
> -    void *client;
> -
> -    DMAPushFn to_dma;
> -    DMAPushFn to_client;
> -};
> -
> -static inline void xlx_dma_connect_client(struct XilinxDMAConnection *dmach,
> -                                          void *c, DMAPushFn f)
> -{
> -    dmach->client = c;
> -    dmach->to_client = f;
> -}
> -
> -static inline void xlx_dma_connect_dma(struct XilinxDMAConnection *dmach,
> -                                       void *d, DMAPushFn f)
> -{
> -    dmach->dma = d;
> -    dmach->to_dma = f;
> -}
> -
> -static inline
> -void xlx_dma_push_to_dma(struct XilinxDMAConnection *dmach,
> -                         uint8_t *buf, size_t len, uint32_t *app)
> -{
> -    dmach->to_dma(dmach->dma, buf, len, app);
> -}
> -static inline
> -void xlx_dma_push_to_client(struct XilinxDMAConnection *dmach,
> -                            uint8_t *buf, size_t len, uint32_t *app)
> -{
> -    dmach->to_client(dmach->client, buf, len, app);
> -}
> -
> diff --git a/hw/xilinx_axienet.c b/hw/xilinx_axienet.c
> index adfaf2c..5e59c3d 100644
> --- a/hw/xilinx_axienet.c
> +++ b/hw/xilinx_axienet.c
> @@ -28,7 +28,7 @@
>  #include "net.h"
>  #include "net/checksum.h"
>  
> -#include "xilinx_axidma.h"
> +#include "stream.h"
>  
>  #define DPHY(x)
>  
> @@ -310,7 +310,7 @@ struct XilinxAXIEnet {
>      SysBusDevice busdev;
>      MemoryRegion iomem;
>      qemu_irq irq;
> -    void *dmach;
> +    StreamSlave *tx_dev;
>      NICState *nic;
>      NICConf conf;
>  
> @@ -773,7 +773,7 @@ static ssize_t eth_rx(NetClientState *nc, const uint8_t *buf, size_t size)
>      /* Good frame.  */
>      app[2] |= 1 << 6;
>  
> -    xlx_dma_push_to_dma(s->dmach, (void *)s->rxmem, size, app);
> +    axi_stream_push(s->tx_dev, (void *)s->rxmem, size, app);
>  
>      s->regs[R_IS] |= IS_RX_COMPLETE;
>      enet_update_irq(s);
> @@ -789,9 +789,9 @@ static void eth_cleanup(NetClientState *nc)
>  }
>  
>  static void
> -axienet_stream_push(void *opaque, uint8_t *buf, size_t size, uint32_t *hdr)
> +axienet_stream_push(StreamSlave *obj, uint8_t *buf, size_t size, uint32_t *hdr)
>  {
> -    struct XilinxAXIEnet *s = opaque;
> +    struct XilinxAXIEnet *s = FROM_SYSBUS(typeof(*s), SYS_BUS_DEVICE(obj));
>  
>      /* TX enable ?  */
>      if (!(s->tc & TC_TX)) {
> @@ -845,12 +845,6 @@ static int xilinx_enet_init(SysBusDevice *dev)
>  
>      sysbus_init_irq(dev, &s->irq);
>  
> -    if (!s->dmach) {
> -        hw_error("Unconnected Xilinx Ethernet MAC.\n");
> -    }
> -
> -    xlx_dma_connect_client(s->dmach, s, axienet_stream_push);
> -
>      memory_region_init_io(&s->iomem, &enet_ops, s, "enet", 0x40000);
>      sysbus_init_mmio(dev, &s->iomem);
>  
> @@ -870,11 +864,18 @@ static int xilinx_enet_init(SysBusDevice *dev)
>      return 0;
>  }
>  
> +static void xilinx_enet_initfn(Object *obj)
> +{
> +    struct XilinxAXIEnet *s = FROM_SYSBUS(typeof(*s), SYS_BUS_DEVICE(obj));
> +
> +    object_property_add_link(obj, "axistream-connected", TYPE_STREAM_SLAVE,
> +                             (Object **) &s->tx_dev, NULL);
> +}
> +
>  static Property xilinx_enet_properties[] = {
>      DEFINE_PROP_UINT32("phyaddr", struct XilinxAXIEnet, c_phyaddr, 7),
>      DEFINE_PROP_UINT32("rxmem", struct XilinxAXIEnet, c_rxmem, 0x1000),
>      DEFINE_PROP_UINT32("txmem", struct XilinxAXIEnet, c_txmem, 0x1000),
> -    DEFINE_PROP_PTR("dmach", struct XilinxAXIEnet, dmach),
>      DEFINE_NIC_PROPERTIES(struct XilinxAXIEnet, conf),
>      DEFINE_PROP_END_OF_LIST(),
>  };
> @@ -883,9 +884,11 @@ static void xilinx_enet_class_init(ObjectClass *klass, void *data)
>  {
>      DeviceClass *dc = DEVICE_CLASS(klass);
>      SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass);
> +    StreamSlaveClass *ssc = STREAM_SLAVE_CLASS(klass);
>  
>      k->init = xilinx_enet_init;
>      dc->props = xilinx_enet_properties;
> +    ssc->push = axienet_stream_push;
>  }
>  
>  static TypeInfo xilinx_enet_info = {
> @@ -893,6 +896,11 @@ static TypeInfo xilinx_enet_info = {
>      .parent        = TYPE_SYS_BUS_DEVICE,
>      .instance_size = sizeof(struct XilinxAXIEnet),
>      .class_init    = xilinx_enet_class_init,
> +    .instance_init = xilinx_enet_initfn,
> +    .interfaces = (InterfaceInfo[]) {
> +            { TYPE_STREAM_SLAVE },
> +            { }
> +    }
>  };
>  
>  static void xilinx_enet_register_types(void)
> -- 
> 1.7.0.4
>