[Qemu-devel] [PATCH] xilinx_spips: Make dma transactions as per dma_burst_size

[Sai Pavan Boddu <sai.pavan.boddu@xilinx.com>]

Qspi dma has a burst length of 64 bytes, So limit transaction length to
64 max.

Signed-off-by: Sai Pavan Boddu <saipava@xilinx.com>
---
 hw/ssi/xilinx_spips.c         | 18 +++++++++++++++---
 include/hw/ssi/xilinx_spips.h |  3 ++-
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/hw/ssi/xilinx_spips.c b/hw/ssi/xilinx_spips.c
index 03f5fae..ea006c4 100644
--- a/hw/ssi/xilinx_spips.c
+++ b/hw/ssi/xilinx_spips.c
@@ -851,12 +851,17 @@ static void xlnx_zynqmp_qspips_notify(void *opaque)
     {
         size_t ret;
         uint32_t num;
-        const void *rxd = pop_buf(recv_fifo, 4, &num);
+        const void *rxd;
+        int len;
+
+        len = recv_fifo->num >= rq->dma_burst_size ? rq->dma_burst_size :
+                                                   recv_fifo->num;
+        rxd = pop_buf(recv_fifo, len, &num);
 
         memcpy(rq->dma_buf, rxd, num);
 
-        ret = stream_push(rq->dma, rq->dma_buf, 4);
-        assert(ret == 4);
+        ret = stream_push(rq->dma, rq->dma_buf, num);
+        assert(ret == num);
         xlnx_zynqmp_qspips_check_flush(rq);
     }
 }
@@ -1337,6 +1342,7 @@ static void xlnx_zynqmp_qspips_realize(DeviceState *dev, Error **errp)
     fifo8_create(&s->rx_fifo_g, xsc->rx_fifo_size);
     fifo8_create(&s->tx_fifo_g, xsc->tx_fifo_size);
     fifo32_create(&s->fifo_g, 32);
+    s->dma_buf = g_new0(uint8_t, s->dma_burst_size);
 }
 
 static void xlnx_zynqmp_qspips_init(Object *obj)
@@ -1411,6 +1417,11 @@ static const VMStateDescription vmstate_xlnx_zynqmp_qspips = {
     }
 };
 
+static Property xilinx_zynqmp_qspips_properties[] = {
+    DEFINE_PROP_UINT32("dma-burst-size", XlnxZynqMPQSPIPS, dma_burst_size, 64),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
 static Property xilinx_qspips_properties[] = {
     /* We had to turn this off for 2.10 as it is not compatible with migration.
      * It can be enabled but will prevent the device to be migrated.
@@ -1463,6 +1474,7 @@ static void xlnx_zynqmp_qspips_class_init(ObjectClass *klass, void * data)
     dc->realize = xlnx_zynqmp_qspips_realize;
     dc->reset = xlnx_zynqmp_qspips_reset;
     dc->vmsd = &vmstate_xlnx_zynqmp_qspips;
+    dc->props = xilinx_zynqmp_qspips_properties;
     xsc->reg_ops = &xlnx_zynqmp_qspips_ops;
     xsc->rx_fifo_size = RXFF_A_Q;
     xsc->tx_fifo_size = TXFF_A_Q;
diff --git a/include/hw/ssi/xilinx_spips.h b/include/hw/ssi/xilinx_spips.h
index d398a4e..cca1813 100644
--- a/include/hw/ssi/xilinx_spips.h
+++ b/include/hw/ssi/xilinx_spips.h
@@ -95,7 +95,8 @@ typedef struct {
     XilinxQSPIPS parent_obj;
 
     StreamSlave *dma;
-    uint8_t dma_buf[4];
+    uint8_t *dma_buf;
+    uint32_t dma_burst_size;
     int gqspi_irqline;
 
     uint32_t regs[XLNX_ZYNQMP_SPIPS_R_MAX];
-- 
2.7.4