@@ -1,11 +1,20 @@
#include "hw/stream.h"
-void
+size_t
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);
+ return k->push(sink, buf, len, app);
+}
+
+bool
+stream_can_push(StreamSlave *sink, StreamCanPushNotifyFn notify,
+ void *notify_opaque)
+{
+ StreamSlaveClass *k = STREAM_SLAVE_GET_CLASS(sink);
+
+ return k->can_push ? k->can_push(sink, notify, notify_opaque) : true;
}
static const TypeInfo stream_slave_info = {
@@ -18,14 +18,41 @@ typedef struct StreamSlave {
Object Parent;
} StreamSlave;
+typedef void (*StreamCanPushNotifyFn)(void *opaque);
+
typedef struct StreamSlaveClass {
InterfaceClass parent;
-
- void (*push)(StreamSlave *obj, unsigned char *buf, size_t len,
+ /**
+ * can push - determine if a stream slave is capable of accepting at least
+ * one byte of data. Returns false if cannot accept. If not implemented, the
+ * slave is assumed to always be capable of recieveing.
+ * @notify: Optional callback that the slave will call when the slave is
+ * capable of recieving again. Only called if false is returned.
+ * @notify_opaque: opaque data to pass to notify call.
+ */
+ bool (*can_push)(StreamSlave *obj, StreamCanPushNotifyFn notify,
+ void *notify_opaque);
+ /**
+ * push - push data to a Stream slave. The number of bytes pushed is
+ * returned. If the slave short returns, the master must wait before trying
+ * again, the slave may continue to just return 0 waiting for the vm time to
+ * advance. The can_push() function can be used to trap the point in time
+ * where the slave is ready to recieve agai, otherwise polling on a QEMU
+ * timer will work.
+ * @obj: Stream slave to push to
+ * @buf: Data to write
+ * @len: Maximum number of bytes to write
+ */
+ size_t (*push)(StreamSlave *obj, unsigned char *buf, size_t len,
uint32_t *app);
} StreamSlaveClass;
-void
+size_t
stream_push(StreamSlave *sink, uint8_t *buf, size_t len, uint32_t *app);
+bool
+stream_can_push(StreamSlave *sink, StreamCanPushNotifyFn notify,
+ void *notify_opaque);
+
+
#endif /* STREAM_H */
@@ -381,7 +381,7 @@ static void xilinx_axidma_reset(DeviceState *dev)
}
}
-static void
+static size_t
xilinx_axidma_data_stream_push(StreamSlave *obj, unsigned char *buf, size_t len,
uint32_t *app)
{
@@ -393,6 +393,7 @@ xilinx_axidma_data_stream_push(StreamSlave *obj, unsigned char *buf, size_t len,
}
stream_process_s2mem(s, buf, len, app);
stream_update_irq(s);
+ return len;
}
static uint64_t axidma_read(void *opaque, hwaddr addr,
@@ -813,7 +813,7 @@ static void eth_cleanup(NetClientState *nc)
g_free(s);
}
-static void
+static size_t
xilinx_axienet_data_stream_push(StreamSlave *obj, uint8_t *buf, size_t size,
uint32_t *hdr)
{
@@ -822,13 +822,13 @@ xilinx_axienet_data_stream_push(StreamSlave *obj, uint8_t *buf, size_t size,
/* TX enable ? */
if (!(s->tc & TC_TX)) {
- return;
+ return size;
}
/* Jumbo or vlan sizes ? */
if (!(s->tc & TC_JUM)) {
if (size > 1518 && size <= 1522 && !(s->tc & TC_VLAN)) {
- return;
+ return size;
}
}
@@ -856,6 +856,8 @@ xilinx_axienet_data_stream_push(StreamSlave *obj, uint8_t *buf, size_t size,
s->stats.tx_bytes += size;
s->regs[R_IS] |= IS_TX_COMPLETE;
enet_update_irq(s);
+
+ return size;
}
static NetClientInfo net_xilinx_enet_info = {
Add basic flow control to stream. A stream slave may return short, indicating that it is not capable of accepting any more data at the present time. Polling or a callback can be used via the can_push() function to determine when the slave can receive again. Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com> --- hw/stream.c | 13 +++++++++++-- hw/stream.h | 33 ++++++++++++++++++++++++++++++--- hw/xilinx_axidma.c | 3 ++- hw/xilinx_axienet.c | 8 +++++--- 4 files changed, 48 insertions(+), 9 deletions(-)