hw/dma/xilinx_axidma: s2mm: Support stream fragments

Add support for stream fragments.

Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@xilinx.com>
Message-Id: <20200506082513.18751-9-edgar.iglesias@gmail.com>

hw/dma/xilinx_axidma.c

@@ -110,6 +110,7 @@ struct Stream {
 
     int nr;
 
+    bool sof;
     struct SDesc desc;
     unsigned int complete_cnt;
     uint32_t regs[R_MAX];
@@ -174,6 +175,7 @@ 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.  */
+    s->sof = true;
 }
 
 /* Map an offset addr into a channel index.  */
@@ -321,12 +323,11 @@ static void stream_process_mem2s(struct Stream *s, StreamSlave *tx_data_dev,
 }
 
 static size_t stream_process_s2mem(struct Stream *s, unsigned char *buf,
-                                   size_t len)
+                                   size_t len, bool eop)
 {
     uint32_t prev_d;
     unsigned int rxlen;
     size_t pos = 0;
-    int sof = 1;
 
     if (!stream_running(s) || stream_idle(s)) {
         return 0;
@@ -352,16 +353,16 @@ static size_t stream_process_s2mem(struct Stream *s, unsigned char *buf,
         pos += rxlen;
 
         /* Update the descriptor.  */
-        if (!len) {
+        if (eop) {
             stream_complete(s);
             memcpy(s->desc.app, s->app, sizeof(s->desc.app));
             s->desc.status |= SDESC_STATUS_EOF;
         }
 
-        s->desc.status |= sof << SDESC_STATUS_SOF_BIT;
+        s->desc.status |= s->sof << SDESC_STATUS_SOF_BIT;
         s->desc.status |= SDESC_STATUS_COMPLETE;
         stream_desc_store(s, s->regs[R_CURDESC]);
-        sof = 0;
+        s->sof = eop;
 
         /* Advance.  */
         prev_d = s->regs[R_CURDESC];
@@ -426,8 +427,7 @@ xilinx_axidma_data_stream_push(StreamSlave *obj, unsigned char *buf, size_t len,
     struct Stream *s = &ds->dma->streams[1];
     size_t ret;
 
-    assert(eop);
-    ret = stream_process_s2mem(s, buf, len);
+    ret = stream_process_s2mem(s, buf, len, eop);
     stream_update_irq(s);
     return ret;
 }