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hw/net/allwinner-sun8i-emac: Use AddressSpace for DMA transfers
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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>
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@philmd @pm215
philmd authored and pm215 committed Aug 28, 2020
1 parent b3aec95 commit 4757cb8
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Showing 3 changed files with 38 additions and 16 deletions.
2 changes: 2 additions & 0 deletions hw/arm/allwinner-h3.c
View file
Expand Up @@ -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,
Expand Down
46 changes: 30 additions & 16 deletions hw/net/allwinner-sun8i-emac.c
View file
Expand Up @@ -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"
Expand All @@ -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 */
Expand Down Expand Up @@ -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) {
Expand All @@ -352,15 +355,16 @@ 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)
{
uint32_t desc_addr = start_addr;

/* 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) {
Expand All @@ -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)
Expand Down Expand Up @@ -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);

Expand All @@ -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;
Expand Down Expand Up @@ -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) {
Expand All @@ -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 */
Expand Down Expand Up @@ -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;
Expand All @@ -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;
Expand Down Expand Up @@ -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);
Expand All @@ -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(),
};

Expand Down
6 changes: 6 additions & 0 deletions include/hw/net/allwinner-sun8i-emac.h
View file
Expand Up @@ -49,6 +49,12 @@ typedef struct AwSun8iEmacState {
/** Interrupt output signal to notify CPU */
qemu_irq irq;

/** Memory region where DMA transfers are done */
MemoryRegion *dma_mr;

/** Address space used internally for DMA transfers */
AddressSpace dma_as;

/** Generic Network Interface Controller (NIC) for networking API */
NICState *nic;

Expand Down

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