[PATCH] hw/arm: virt: Add SBSA watchdog

[Jan Kiszka]

From: Jan Kiszka <jan.kiszka@siemens.com>

The virt machine lacks a watchdog so far while the sbsa-ref has a simple
model that is also supported by Linux and even U-Boot. Let's take it to
allow, e.g., system integration tests of A/B software update under
watchdog monitoring.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---

An alternative could be sp805. However, QEMU has no support for that
device yet.

 hw/arm/Kconfig        |  1 +
 hw/arm/virt.c         | 35 +++++++++++++++++++++++++++++++++++
 include/hw/arm/virt.h |  3 +++
 3 files changed, 39 insertions(+)

diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index 97f3b38019..8df04a3533 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -29,6 +29,7 @@ config ARM_VIRT
     select ACPI_APEI
     select ACPI_VIOT
     select VIRTIO_MEM_SUPPORTED
+    select WDT_SBSA

 config CHEETAH
     bool
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index f94278935f..a7b85438a8 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -78,6 +78,7 @@
 #include "hw/virtio/virtio-mem-pci.h"
 #include "hw/virtio/virtio-iommu.h"
 #include "hw/char/pl011.h"
+#include "hw/watchdog/sbsa_gwdt.h"
 #include "qemu/guest-random.h"

 #define DEFINE_VIRT_MACHINE_LATEST(major, minor, latest) \
@@ -154,6 +155,8 @@ static const MemMapEntry base_memmap[] = {
     [VIRT_NVDIMM_ACPI] =        { 0x09090000, NVDIMM_ACPI_IO_LEN},
     [VIRT_PVTIME] =             { 0x090a0000, 0x00010000 },
     [VIRT_SECURE_GPIO] =        { 0x090b0000, 0x00001000 },
+    [VIRT_GWDT_CONTROL] =       { 0x090c0000, 0x00001000 },
+    [VIRT_GWDT_REFRESH] =       { 0x090d0000, 0x00001000 },
     [VIRT_MMIO] =               { 0x0a000000, 0x00000200 },
     /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */
     [VIRT_PLATFORM_BUS] =       { 0x0c000000, 0x02000000 },
@@ -190,6 +193,7 @@ static const int a15irqmap[] = {
     [VIRT_GPIO] = 7,
     [VIRT_SECURE_UART] = 8,
     [VIRT_ACPI_GED] = 9,
+    [VIRT_GWDT_WS0] = 10,
     [VIRT_MMIO] = 16, /* ...to 16 + NUM_VIRTIO_TRANSPORTS - 1 */
     [VIRT_GIC_V2M] = 48, /* ...to 48 + NUM_GICV2M_SPIS - 1 */
     [VIRT_SMMU] = 74,    /* ...to 74 + NUM_SMMU_IRQS - 1 */
@@ -902,6 +906,35 @@ static void create_rtc(const VirtMachineState *vms)
     g_free(nodename);
 }

+static void create_wdt(const VirtMachineState *vms)
+{
+    hwaddr cbase = vms->memmap[VIRT_GWDT_CONTROL].base;
+    hwaddr csize = vms->memmap[VIRT_GWDT_CONTROL].size;
+    hwaddr rbase = vms->memmap[VIRT_GWDT_REFRESH].base;
+    hwaddr rsize = vms->memmap[VIRT_GWDT_REFRESH].size;
+    DeviceState *dev = qdev_new(TYPE_WDT_SBSA);
+    SysBusDevice *s = SYS_BUS_DEVICE(dev);
+    int irq = vms->irqmap[VIRT_GWDT_WS0];
+    const char compat[] = "arm,sbsa-gwdt";
+    MachineState *ms = MACHINE(vms);
+    char *nodename;
+
+    sysbus_realize_and_unref(s, &error_fatal);
+    sysbus_mmio_map(s, 1, cbase);
+    sysbus_mmio_map(s, 0, rbase);
+    sysbus_connect_irq(s, 0, qdev_get_gpio_in(vms->gic, irq));
+
+    nodename = g_strdup_printf("/watchdog@%" PRIx64, cbase);
+    qemu_fdt_add_subnode(ms->fdt, nodename);
+    qemu_fdt_setprop(ms->fdt, nodename, "compatible", compat, sizeof(compat));
+    qemu_fdt_setprop_sized_cells(ms->fdt, nodename, "reg",
+                                 2, cbase, 2, csize, 2, rbase, 2, rsize);
+    qemu_fdt_setprop_cells(ms->fdt, nodename, "interrupts",
+                           GIC_FDT_IRQ_TYPE_SPI, irq,
+                           GIC_FDT_IRQ_FLAGS_LEVEL_HI);
+    g_free(nodename);
+}
+
 static DeviceState *gpio_key_dev;
 static void virt_powerdown_req(Notifier *n, void *opaque)
 {
@@ -2240,6 +2273,8 @@ static void machvirt_init(MachineState *machine)

     create_rtc(vms);

+    create_wdt(vms);
+
     create_pcie(vms);

     if (has_ged && aarch64 && firmware_loaded && virt_is_acpi_enabled(vms)) {
diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index 15feabac63..7f295f771e 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -86,6 +86,9 @@ enum {
     VIRT_ACPI_GED,
     VIRT_NVDIMM_ACPI,
     VIRT_PVTIME,
+    VIRT_GWDT_WS0,
+    VIRT_GWDT_CONTROL,
+    VIRT_GWDT_REFRESH,
     VIRT_LOWMEMMAP_LAST,
 };

--
2.34.1