hw/net/allwinner-sun8i-emac: Use AddressSpace for DMA transfers

Allow the device to execute the DMA transfers in a different
AddressSpace.

The H3 SoC keeps using the system_memory address space,
but via the proper dma_memory_access() API.

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Tested-by: Niek Linnenbank <nieklinnenbank@gmail.com>
Message-id: 20200814122907.27732-1-f4bug@amsat.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 32 insertions, 16 deletions

diff --git a/hw/arm/allwinner-h3.c b/hw/arm/allwinner-h3.c
index 43a8d3dc48..76ac51a3ef 100644
--- a/hw/arm/allwinner-h3.c
+++ b/hw/arm/allwinner-h3.c
@@ -365,6 +365,8 @@ static void allwinner_h3_realize(DeviceState *dev, Error **errp)
         qemu_check_nic_model(&nd_table[0], TYPE_AW_SUN8I_EMAC);
         qdev_set_nic_properties(DEVICE(&s->emac), &nd_table[0]);
     }
+    object_property_set_link(OBJECT(&s->emac), "dma-memory",
+                             OBJECT(get_system_memory()), &error_fatal);
     sysbus_realize(SYS_BUS_DEVICE(&s->emac), &error_fatal);
     sysbus_mmio_map(SYS_BUS_DEVICE(&s->emac), 0, s->memmap[AW_H3_EMAC]);
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->emac), 0,
diff --git a/hw/net/allwinner-sun8i-emac.c b/hw/net/allwinner-sun8i-emac.c
index 28637ff4c1..38d328587e 100644
--- a/hw/net/allwinner-sun8i-emac.c
+++ b/hw/net/allwinner-sun8i-emac.c
@@ -19,6 +19,7 @@
 
 #include "qemu/osdep.h"
 #include "qemu/units.h"
+#include "qapi/error.h"
 #include "hw/sysbus.h"
 #include "migration/vmstate.h"
 #include "net/net.h"
@@ -29,6 +30,7 @@
 #include "net/checksum.h"
 #include "qemu/module.h"
 #include "exec/cpu-common.h"
+#include "sysemu/dma.h"
 #include "hw/net/allwinner-sun8i-emac.h"
 
 /* EMAC register offsets */
@@ -337,12 +339,13 @@ static void allwinner_sun8i_emac_update_irq(AwSun8iEmacState *s)
     qemu_set_irq(s->irq, (s->int_sta & s->int_en) != 0);
 }
 
-static uint32_t allwinner_sun8i_emac_next_desc(FrameDescriptor *desc,
+static uint32_t allwinner_sun8i_emac_next_desc(AwSun8iEmacState *s,
+                                               FrameDescriptor *desc,
                                                size_t min_size)
 {
     uint32_t paddr = desc->next;
 
-    cpu_physical_memory_read(paddr, desc, sizeof(*desc));
+    dma_memory_read(&s->dma_as, paddr, desc, sizeof(*desc));
 
     if ((desc->status & DESC_STATUS_CTL) &&
         (desc->status2 & DESC_STATUS2_BUF_SIZE_MASK) >= min_size) {
@@ -352,7 +355,8 @@ static uint32_t allwinner_sun8i_emac_next_desc(FrameDescriptor *desc,
     }
 }
 
-static uint32_t allwinner_sun8i_emac_get_desc(FrameDescriptor *desc,
+static uint32_t allwinner_sun8i_emac_get_desc(AwSun8iEmacState *s,
+                                              FrameDescriptor *desc,
                                               uint32_t start_addr,
                                               size_t min_size)
 {
@@ -360,7 +364,7 @@ static uint32_t allwinner_sun8i_emac_get_desc(FrameDescriptor *desc,
 
     /* Note that the list is a cycle. Last entry points back to the head. */
     while (desc_addr != 0) {
-        cpu_physical_memory_read(desc_addr, desc, sizeof(*desc));
+        dma_memory_read(&s->dma_as, desc_addr, desc, sizeof(*desc));
 
         if ((desc->status & DESC_STATUS_CTL) &&
             (desc->status2 & DESC_STATUS2_BUF_SIZE_MASK) >= min_size) {
@@ -379,20 +383,21 @@ static uint32_t allwinner_sun8i_emac_rx_desc(AwSun8iEmacState *s,
                                              FrameDescriptor *desc,
                                              size_t min_size)
 {
-    return allwinner_sun8i_emac_get_desc(desc, s->rx_desc_curr, min_size);
+    return allwinner_sun8i_emac_get_desc(s, desc, s->rx_desc_curr, min_size);
 }
 
 static uint32_t allwinner_sun8i_emac_tx_desc(AwSun8iEmacState *s,
                                              FrameDescriptor *desc,
                                              size_t min_size)
 {
-    return allwinner_sun8i_emac_get_desc(desc, s->tx_desc_head, min_size);
+    return allwinner_sun8i_emac_get_desc(s, desc, s->tx_desc_head, min_size);
 }
 
-static void allwinner_sun8i_emac_flush_desc(FrameDescriptor *desc,
+static void allwinner_sun8i_emac_flush_desc(AwSun8iEmacState *s,
+                                            FrameDescriptor *desc,
                                             uint32_t phys_addr)
 {
-    cpu_physical_memory_write(phys_addr, desc, sizeof(*desc));
+    dma_memory_write(&s->dma_as, phys_addr, desc, sizeof(*desc));
 }
 
 static bool allwinner_sun8i_emac_can_receive(NetClientState *nc)
@@ -450,8 +455,8 @@ static ssize_t allwinner_sun8i_emac_receive(NetClientState *nc,
                             << RX_DESC_STATUS_FRM_LEN_SHIFT;
         }
 
-        cpu_physical_memory_write(desc.addr, buf, desc_bytes);
-        allwinner_sun8i_emac_flush_desc(&desc, s->rx_desc_curr);
+        dma_memory_write(&s->dma_as, desc.addr, buf, desc_bytes);
+        allwinner_sun8i_emac_flush_desc(s, &desc, s->rx_desc_curr);
         trace_allwinner_sun8i_emac_receive(s->rx_desc_curr, desc.addr,
                                            desc_bytes);
 
@@ -465,7 +470,7 @@ static ssize_t allwinner_sun8i_emac_receive(NetClientState *nc,
         bytes_left -= desc_bytes;
 
         /* Move to the next descriptor */
-        s->rx_desc_curr = allwinner_sun8i_emac_next_desc(&desc, 64);
+        s->rx_desc_curr = allwinner_sun8i_emac_next_desc(s, &desc, 64);
         if (!s->rx_desc_curr) {
             /* Not enough buffer space available */
             s->int_sta |= INT_STA_RX_BUF_UA;
@@ -501,10 +506,10 @@ static void allwinner_sun8i_emac_transmit(AwSun8iEmacState *s)
             desc.status |= TX_DESC_STATUS_LENGTH_ERR;
             break;
         }
-        cpu_physical_memory_read(desc.addr, packet_buf + packet_bytes, bytes);
+        dma_memory_read(&s->dma_as, desc.addr, packet_buf + packet_bytes, bytes);
         packet_bytes += bytes;
         desc.status &= ~DESC_STATUS_CTL;
-        allwinner_sun8i_emac_flush_desc(&desc, s->tx_desc_curr);
+        allwinner_sun8i_emac_flush_desc(s, &desc, s->tx_desc_curr);
 
         /* After the last descriptor, send the packet */
         if (desc.status2 & TX_DESC_STATUS2_LAST_DESC) {
@@ -519,7 +524,7 @@ static void allwinner_sun8i_emac_transmit(AwSun8iEmacState *s)
             packet_bytes = 0;
             transmitted++;
         }
-        s->tx_desc_curr = allwinner_sun8i_emac_next_desc(&desc, 0);
+        s->tx_desc_curr = allwinner_sun8i_emac_next_desc(s, &desc, 0);
     }
 
     /* Raise transmit completed interrupt */
@@ -623,7 +628,7 @@ static uint64_t allwinner_sun8i_emac_read(void *opaque, hwaddr offset,
         break;
     case REG_TX_CUR_BUF:        /* Transmit Current Buffer */
         if (s->tx_desc_curr != 0) {
-            cpu_physical_memory_read(s->tx_desc_curr, &desc, sizeof(desc));
+            dma_memory_read(&s->dma_as, s->tx_desc_curr, &desc, sizeof(desc));
             value = desc.addr;
         } else {
             value = 0;
@@ -636,7 +641,7 @@ static uint64_t allwinner_sun8i_emac_read(void *opaque, hwaddr offset,
         break;
     case REG_RX_CUR_BUF:        /* Receive Current Buffer */
         if (s->rx_desc_curr != 0) {
-            cpu_physical_memory_read(s->rx_desc_curr, &desc, sizeof(desc));
+            dma_memory_read(&s->dma_as, s->rx_desc_curr, &desc, sizeof(desc));
             value = desc.addr;
         } else {
             value = 0;
@@ -790,6 +795,13 @@ static void allwinner_sun8i_emac_realize(DeviceState *dev, Error **errp)
 {
     AwSun8iEmacState *s = AW_SUN8I_EMAC(dev);
 
+    if (!s->dma_mr) {
+        error_setg(errp, TYPE_AW_SUN8I_EMAC " 'dma-memory' link not set");
+        return;
+    }
+
+    address_space_init(&s->dma_as, s->dma_mr, "emac-dma");
+
     qemu_macaddr_default_if_unset(&s->conf.macaddr);
     s->nic = qemu_new_nic(&net_allwinner_sun8i_emac_info, &s->conf,
                            object_get_typename(OBJECT(dev)), dev->id, s);
@@ -799,6 +811,8 @@ static void allwinner_sun8i_emac_realize(DeviceState *dev, Error **errp)
 static Property allwinner_sun8i_emac_properties[] = {
     DEFINE_NIC_PROPERTIES(AwSun8iEmacState, conf),
     DEFINE_PROP_UINT8("phy-addr", AwSun8iEmacState, mii_phy_addr, 0),
+    DEFINE_PROP_LINK("dma-memory", AwSun8iEmacState, dma_mr,
+                     TYPE_MEMORY_REGION, MemoryRegion *),
     DEFINE_PROP_END_OF_LIST(),
 };