[PATCH 04/19] hw/net/bcm2838_genet: add GENET stub device

[Marcelo Manzo <marcelomanzo@gmail.com>]

Add a bare-bones BCM2838 GENET (Gigabit Ethernet) sysbus device:
MMIO region registration, an out-of-range read/write handler that
just logs, and a reset callback. No register-level behavior yet;
that comes in the following patches.

Adapted from patch 19/41 of Sergey Kambalin's Raspberry Pi 4B
series (patchwork series 829638) against current QEMU master. The
reset callback and class_init() use the current Resettable-phases
API (ResettableClass / resettable_class_set_parent_phases()) rather
than the plain DeviceClass::reset hook the original patch used, and
headers moved under hw/core/, both API changes since the series was
originally posted.

Signed-off-by: Marcelo Manzo <marcelomanzo@gmail.com>
---
 hw/net/bcm2838_genet.c               | 103 +++++++++++++++++++++++++++
 hw/net/meson.build                   |   2 +
 hw/net/trace-events                  |  16 +++++
 include/hw/arm/bcm2838_peripherals.h |   2 +
 include/hw/net/bcm2838_genet.h       |  40 +++++++++++
 5 files changed, 163 insertions(+)
 create mode 100644 hw/net/bcm2838_genet.c
 create mode 100644 include/hw/net/bcm2838_genet.h

diff --git a/hw/net/bcm2838_genet.c b/hw/net/bcm2838_genet.c
new file mode 100644
index 00000000..2ff93a34
--- /dev/null
+++ b/hw/net/bcm2838_genet.c
@@ -0,0 +1,103 @@
+/*
+ * BCM2838 Gigabit Ethernet emulation
+ *
+ * Copyright (C) 2022 Ovchinnikov Vitalii <vitalii.ovchinnikov@auriga.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/module.h"
+#include "qemu/log.h"
+#include "qemu/error-report.h"
+#include "net/eth.h"
+#include "qapi/error.h"
+#include "hw/core/irq.h"
+#include "net/checksum.h"
+#include "system/dma.h"
+#include "hw/core/resettable.h"
+#include "hw/net/bcm2838_genet.h"
+#include "trace.h"
+
+
+static uint64_t bcm2838_genet_read(void *opaque, hwaddr offset, unsigned size)
+{
+    uint64_t value = ~0;
+
+    qemu_log_mask(
+        LOG_GUEST_ERROR,
+        "%s: out-of-range access, %u bytes @ offset 0x%04" PRIx64 "\n",
+        __func__, size, offset);
+
+    trace_bcm2838_genet_read(size, offset, value);
+    return value;
+}
+
+static void bcm2838_genet_write(void *opaque, hwaddr offset, uint64_t value,
+                                unsigned size) {
+    qemu_log_mask(
+        LOG_GUEST_ERROR,
+        "%s: out-of-range access, %u bytes @ offset 0x%04" PRIx64 "\n",
+        __func__, size, offset);
+}
+
+static const MemoryRegionOps bcm2838_genet_ops = {
+    .read = bcm2838_genet_read,
+    .write = bcm2838_genet_write,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+    .impl = {.max_access_size = 4},
+    .valid = {.min_access_size = 4},
+};
+
+
+static void bcm2838_genet_realize(DeviceState *dev, Error **errp)
+{
+    BCM2838GenetState *s = BCM2838_GENET(dev);
+    SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
+
+    /* Controller registers */
+    memory_region_init_io(&s->regs_mr, OBJECT(s), &bcm2838_genet_ops, s,
+                          "bcm2838_genet_regs", sizeof(s->regs));
+    sysbus_init_mmio(sbd, &s->regs_mr);
+}
+
+static void bcm2838_genet_phy_reset(BCM2838GenetState *s)
+{
+    trace_bcm2838_genet_phy_reset("done");
+}
+
+static void bcm2838_genet_reset(Object *obj, ResetType type)
+{
+    BCM2838GenetState *s = BCM2838_GENET(obj);
+
+    memset(&s->regs, 0x00, sizeof(s->regs));
+
+    trace_bcm2838_genet_reset("done");
+
+    bcm2838_genet_phy_reset(s);
+}
+
+static void bcm2838_genet_class_init(ObjectClass *class, const void *data)
+{
+    static ResettablePhases unused_parent_phases;
+    DeviceClass *dc = DEVICE_CLASS(class);
+    ResettableClass *rc = RESETTABLE_CLASS(class);
+
+    dc->realize = bcm2838_genet_realize;
+    resettable_class_set_parent_phases(rc, NULL, bcm2838_genet_reset, NULL,
+                                       &unused_parent_phases);
+}
+
+static const TypeInfo bcm2838_genet_info = {
+    .name       = TYPE_BCM2838_GENET,
+    .parent     = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(BCM2838GenetState),
+    .class_init = bcm2838_genet_class_init,
+};
+
+static void bcm2838_genet_register(void)
+{
+    type_register_static(&bcm2838_genet_info);
+}
+
+type_init(bcm2838_genet_register)
diff --git a/hw/net/meson.build b/hw/net/meson.build
index 84f142df..e290e179 100644
--- a/hw/net/meson.build
+++ b/hw/net/meson.build
@@ -69,4 +69,6 @@ system_ss.add(when: 'CONFIG_ROCKER', if_true: files(
 stub_ss.add(files('rocker/rocker-stubs.c'))
 system_ss.add(files('rocker/rocker-hmp-cmds.c'))
 
+system_ss.add(when: 'CONFIG_RASPI', if_true: files('bcm2838_genet.c'))
+
 subdir('can')
diff --git a/hw/net/trace-events b/hw/net/trace-events
index 001a20b0..2dde33e8 100644
--- a/hw/net/trace-events
+++ b/hw/net/trace-events
@@ -528,3 +528,19 @@ xen_netdev_rx(int dev, int idx, int status, int flags) "vif%u idx %d status %d f
 ethlite_pkt_lost(uint32_t rx_ctrl) "rx_ctrl:0x%" PRIx32
 ethlite_pkt_size_too_big(uint64_t size) "size:0x%" PRIx64
 ethlite_pkt_tx_size_too_big(uint64_t size) "size:0x%" PRIx64
+# bcm2838_genet.c
+bcm2838_genet_read(unsigned int size, uint64_t offset, uint64_t value) "%u bytes @ 0x%04" PRIx64 ": 0x%016" PRIx64
+bcm2838_genet_write(unsigned int size, uint64_t offset, uint64_t value) "%u bytes @ 0x%04" PRIx64 ": 0x%016" PRIx64
+bcm2838_genet_can_receive(const char *state) "receive is %s"
+bcm2838_genet_receive(ssize_t bytes_received) "%zd bytes received"
+bcm2838_genet_phy_update_link(const char *link_state) "link is %s"
+bcm2838_genet_phy_reset(const char *status) "PHY reset %s"
+bcm2838_genet_reset(const char *status) "MAC reset %s"
+bcm2838_genet_mac_address(const char *info) "%s"
+bcm2838_genet_tx_dma(const char *dma_state) "TX DMA %s"
+bcm2838_genet_tx_dma_ring(uint32_t ring_en) "TX DMA enabled rings: 0x%05x"
+bcm2838_genet_tx_dma_ring_buf(uint32_t ring_buf_en) "TX DMA enabled ring buffers: 0x%05x"
+bcm2838_genet_tx_dma_ring_active(unsigned int ring, const char *ring_state) "ring %u is %s"
+bcm2838_genet_tx_request(unsigned int ring_idx, uint32_t prod_idx, uint32_t cons_idx) "ring %u, PROD_INDEX %u, CONS_INDEX %u"
+bcm2838_genet_tx(unsigned int ring_idx, uint64_t desc_idx, uint32_t desc_status, uint64_t data_addr) "ring %u, descriptor %" PRIu64 ": 0x%08x, data @ 0x%08" PRIx64
+bcm2838_genet_rx_dma_ring_active(unsigned int ring, const char *ring_state) "ring %u is %s"
diff --git a/include/hw/arm/bcm2838_peripherals.h b/include/hw/arm/bcm2838_peripherals.h
index 56c0c209..903970a3 100644
--- a/include/hw/arm/bcm2838_peripherals.h
+++ b/include/hw/arm/bcm2838_peripherals.h
@@ -52,6 +52,8 @@
 #define BCM2838_MPHI_OFFSET     0xb200
 #define BCM2838_MPHI_SIZE       0x200
 
+#define GENET_OFFSET            0x1580000
+
 #define TYPE_BCM2838_PERIPHERALS "bcm2838-peripherals"
 OBJECT_DECLARE_TYPE(BCM2838PeripheralState, BCM2838PeripheralClass,
                     BCM2838_PERIPHERALS)
diff --git a/include/hw/net/bcm2838_genet.h b/include/hw/net/bcm2838_genet.h
new file mode 100644
index 00000000..91cf1773
--- /dev/null
+++ b/include/hw/net/bcm2838_genet.h
@@ -0,0 +1,40 @@
+/*
+ * BCM2838 Gigabit Ethernet emulation
+ *
+ * Copyright (C) 2022 Ovchinnikov Vitalii <vitalii.ovchinnikov@auriga.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+
+#ifndef BCM2838_GENET_H
+#define BCM2838_GENET_H
+
+#include "net/net.h"
+#include "hw/core/sysbus.h"
+
+#define TYPE_BCM2838_GENET "bcm2838-genet"
+OBJECT_DECLARE_SIMPLE_TYPE(BCM2838GenetState, BCM2838_GENET)
+
+#define BCM2838_GENET_REV_MAJOR         6
+#define BCM2838_GENET_REV_MINOR         0
+
+typedef struct {
+    uint8_t stub_area[0x10000]; /* temporary stub */
+} BCM2838GenetRegs;
+
+struct BCM2838GenetState {
+    /*< private >*/
+    SysBusDevice parent_obj;
+
+    /*< public >*/
+
+    MemoryRegion regs_mr;
+    AddressSpace dma_as;
+
+    BCM2838GenetRegs regs;
+
+    qemu_irq irq_default;
+    qemu_irq irq_prio;
+};
+
+#endif /* BCM2838_GENET_H */
-- 
2.47.1