[PATCH v3 04/17] arm: virt: create sbsa-gwdt watchdog

[Igor Mammedov <imammedo@redhat.com>]

Allow to use SBSA generic watchdog with virt machine type.
(includes conditional generation of corresponding FDT and
ACPI GTDT descriptors)

Use '-device sbsa-gwdt' to command line to enable it.

Instead of using dynamic sysbus infra to wire up MMIO/IRQ/FDT,
statically assign resources in machine's mem/irq maps and wire
them up at device (pre_)plug handlers. It's similar to dynamic
sysbus wiring, modulo resources are nailed down statically,
and wiring is limited to virt machine only.
(Benefit is that tests don't break anymore on rebase due to
address being stable)

Tested with Fedora 43:
  FDT: -M virt,acpi=off -device sbsa-gwdt
  ACPI: -M virt -device sbsa-gwdt

Note:
Windows sees GTDT, initializes watchdog but instead pinging WRR
it sets/advances WOR to way too large value, so it's never going
to trigger watchdog reboot (it's Windows driver issue though).

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
v3:
  - (Eric) assign MMIO/IRQ statically and abandon most of
     dynamic sysbus machinery.
  - (Peter) set watchdog freq to system clock explicitly,
    machine version compat won't work in case host is not runing
    1GHz clock. (Tested on Jetson machine)
---
 include/hw/arm/virt.h    |  3 +++
 hw/arm/Kconfig           |  1 +
 hw/arm/virt-acpi-build.c | 29 +++++++++++++++++++++++++++--
 hw/arm/virt.c            | 37 +++++++++++++++++++++++++++++++++++++
 hw/core/sysbus-fdt.c     |  2 ++
 hw/watchdog/sbsa_gwdt.c  |  1 +
 6 files changed, 71 insertions(+), 2 deletions(-)

diff --git a/include/hw/arm/virt.h b/include/hw/arm/virt.h
index 171d44c644..22e66d1a11 100644
--- a/include/hw/arm/virt.h
+++ b/include/hw/arm/virt.h
@@ -97,6 +97,9 @@ enum {
     VIRT_NVDIMM_ACPI,
     VIRT_PVTIME,
     VIRT_ACPI_PCIHP,
+    VIRT_GWDT_WS0,
+    VIRT_GWDT_REFRESH,
+    VIRT_GWDT_CONTROL,
     VIRT_LOWMEMMAP_LAST,
 };
 
diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index 500bfdfe2a..962a39247c 100644
--- a/hw/arm/Kconfig
+++ b/hw/arm/Kconfig
@@ -36,6 +36,7 @@ config ARM_VIRT
     select VIRTIO_MEM_SUPPORTED
     select ACPI_CXL
     select ACPI_HMAT
+    select WDT_SBSA
 
 config CUBIEBOARD
     bool
diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index 99490aa7b1..f5b3b4ce48 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -64,6 +64,7 @@
 #include "hw/virtio/virtio-acpi.h"
 #include "target/arm/cpu.h"
 #include "target/arm/multiprocessing.h"
+#include "hw/watchdog/sbsa_gwdt.h"
 
 #include "smmuv3-accel.h"
 #include "tegra241-cmdqv.h"
@@ -868,6 +869,8 @@ build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     const uint32_t irqflags = 0;  /* Interrupt is Level triggered  */
     AcpiTable table = { .sig = "GTDT", .rev = 3, .oem_id = vms->oem_id,
                         .oem_table_id = vms->oem_table_id };
+    uint32_t gtdt_start = table_data->len;
+    Object *wdt = object_resolve_type_unambiguous(TYPE_WDT_SBSA, NULL);
 
     acpi_table_begin(&table, table_data);
 
@@ -898,10 +901,15 @@ build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     build_append_int_noprefix(table_data, irqflags, 4);
     /* CntReadBase Physical address */
     build_append_int_noprefix(table_data, 0xFFFFFFFFFFFFFFFF, 8);
+
     /* Platform Timer Count */
-    build_append_int_noprefix(table_data, 0, 4);
+    build_append_int_noprefix(table_data,  wdt ? 1 : 0, 4);
     /* Platform Timer Offset */
-    build_append_int_noprefix(table_data, 0, 4);
+    build_append_int_noprefix(table_data,
+        wdt ? (table_data->len - gtdt_start) +
+              4 + 4 + 4 /* len of this & following 2 fields to skip */
+            : 0, 4);
+
     if (vms->ns_el2_virt_timer_irq) {
         /* Virtual EL2 Timer GSIV */
         build_append_int_noprefix(table_data, ARCH_TIMER_NS_EL2_VIRT_IRQ, 4);
@@ -911,6 +919,23 @@ build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
         build_append_int_noprefix(table_data, 0, 4);
         build_append_int_noprefix(table_data, 0, 4);
     }
+
+    /* ACPI 6.5 spec: 5.2.25.2 ARM Generic Watchdog Structure (Table 5-124) */
+    if (wdt) {
+        hwaddr rbase = vms->memmap[VIRT_GWDT_REFRESH].base;
+        hwaddr cbase = vms->memmap[VIRT_GWDT_CONTROL].base;
+        int irq = ARM_SPI_BASE + vms->irqmap[VIRT_GWDT_WS0];
+
+        build_append_int_noprefix(table_data, 1 /* Type: Watchdog GT */, 1);
+        build_append_int_noprefix(table_data, 28 /* Length */, 2);
+        build_append_int_noprefix(table_data, 0, 1);  /* Reserved */
+        /* RefreshFrame Physical Address */
+        build_append_int_noprefix(table_data, rbase, 8);
+        /* WatchdogControlFrame Physical Address */
+        build_append_int_noprefix(table_data, cbase, 8);
+        build_append_int_noprefix(table_data, irq, 4); /* Watchdog Timer GSIV */
+        build_append_int_noprefix(table_data, 0, 4); /* Watchdog Timer Flags */
+    }
     acpi_table_end(linker, &table);
 }
 
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index d8d27f2ef6..aacf9b7251 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -95,6 +95,7 @@
 #include "hw/cxl/cxl.h"
 #include "hw/cxl/cxl_host.h"
 #include "qemu/guest-random.h"
+#include "hw/watchdog/sbsa_gwdt.h"
 
 static GlobalProperty arm_virt_compat_defaults[] = {
     { TYPE_VIRTIO_IOMMU_PCI, "aw-bits", "48" },
@@ -214,6 +215,8 @@ static const MemMapEntry base_memmap[] = {
     /* ...repeating for a total of NUM_VIRTIO_TRANSPORTS, each of that size */
     [VIRT_PLATFORM_BUS] =       { 0x0c000000, 0x02000000 },
     [VIRT_SECURE_MEM] =         { 0x0e000000, 0x01000000 },
+    [VIRT_GWDT_REFRESH] =       { 0x0f000000, 0x00001000 },
+    [VIRT_GWDT_CONTROL] =       { 0x0f001000, 0x00001000 },
     [VIRT_PCIE_MMIO] =          { 0x10000000, 0x2eff0000 },
     [VIRT_PCIE_PIO] =           { 0x3eff0000, 0x00010000 },
     [VIRT_PCIE_ECAM] =          { 0x3f000000, 0x01000000 },
@@ -267,6 +270,7 @@ static const int a15irqmap[] = {
     [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 */
+    [VIRT_GWDT_WS0] = 10,
     [VIRT_PLATFORM_BUS] = 112, /* ...to 112 + PLATFORM_BUS_NUM_IRQS -1 */
 };
 
@@ -3820,6 +3824,10 @@ static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
         qlist_append_str(reserved_regions, resv_prop_str);
         qdev_prop_set_array(dev, "reserved-regions", reserved_regions);
         g_free(resv_prop_str);
+    } else if (object_dynamic_cast(OBJECT(dev), TYPE_WDT_SBSA)) {
+        uint64_t cntfrq = object_property_get_int(OBJECT(qemu_get_cpu(0)),
+                                                  "cntfrq", &error_abort);
+        qdev_prop_set_uint64(dev, "clock-frequency", cntfrq);
     } else if (object_dynamic_cast(OBJECT(dev), TYPE_ARM_SMMUV3)) {
         if (vms->legacy_smmuv3_present || vms->iommu == VIRT_IOMMU_VIRTIO) {
             error_setg(errp, "virt machine already has %s set. "
@@ -3871,6 +3879,34 @@ static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
 {
     VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
 
+    if (object_dynamic_cast(OBJECT(dev), TYPE_WDT_SBSA)) {
+        SysBusDevice *s = SYS_BUS_DEVICE(dev);
+        MachineState *ms = MACHINE(vms);
+        hwaddr rbase = vms->memmap[VIRT_GWDT_REFRESH].base;
+        hwaddr cbase = vms->memmap[VIRT_GWDT_CONTROL].base;
+        int irq = vms->irqmap[VIRT_GWDT_WS0];
+
+        sysbus_mmio_map(s, 0, rbase);
+        sysbus_mmio_map(s, 1, cbase);
+        sysbus_connect_irq(s, 0, qdev_get_gpio_in(vms->gic, irq));
+
+        {
+            char *nodename = g_strdup_printf("/watchdog@%" PRIx64, cbase);
+
+            qemu_fdt_add_subnode(ms->fdt, nodename);
+            qemu_fdt_setprop_string(ms->fdt, nodename,
+                                    "compatible", "arm,sbsa-gwdt");
+            qemu_fdt_setprop_sized_cells(ms->fdt, nodename, "reg",
+                                         2, cbase, 2, SBSA_GWDT_CMMIO_SIZE,
+                                         2, rbase, 2, SBSA_GWDT_RMMIO_SIZE);
+            qemu_fdt_setprop_cells(ms->fdt, nodename, "interrupts",
+                                   GIC_FDT_IRQ_TYPE_SPI, irq,
+                                   GIC_FDT_IRQ_FLAGS_LEVEL_HI);
+            qemu_fdt_setprop_cell(ms->fdt, nodename, "timeout-sec", 30);
+            g_free(nodename);
+        }
+    }
+
     if (vms->platform_bus_dev) {
         MachineClass *mc = MACHINE_GET_CLASS(vms);
 
@@ -4123,6 +4159,7 @@ static void virt_machine_class_init(ObjectClass *oc, const void *data)
     machine_class_allow_dynamic_sysbus_dev(mc, TYPE_RAMFB_DEVICE);
     machine_class_allow_dynamic_sysbus_dev(mc, TYPE_UEFI_VARS_SYSBUS);
     machine_class_allow_dynamic_sysbus_dev(mc, TYPE_ARM_SMMUV3);
+    machine_class_allow_dynamic_sysbus_dev(mc, TYPE_WDT_SBSA);
 #ifdef CONFIG_TPM
     machine_class_allow_dynamic_sysbus_dev(mc, TYPE_TPM_TIS_SYSBUS);
 #endif
diff --git a/hw/core/sysbus-fdt.c b/hw/core/sysbus-fdt.c
index 89d0c46445..12238570b5 100644
--- a/hw/core/sysbus-fdt.c
+++ b/hw/core/sysbus-fdt.c
@@ -36,6 +36,7 @@
 #include "hw/display/ramfb.h"
 #include "hw/uefi/var-service-api.h"
 #include "hw/arm/fdt.h"
+#include "hw/watchdog/sbsa_gwdt.h"
 
 /*
  * internal struct that contains the information to create dynamic
@@ -140,6 +141,7 @@ static const BindingEntry bindings[] = {
     TYPE_BINDING(TYPE_ARM_SMMUV3, no_fdt_node),
     TYPE_BINDING(TYPE_RAMFB_DEVICE, no_fdt_node),
     TYPE_BINDING(TYPE_UEFI_VARS_SYSBUS, add_uefi_vars_node),
+    TYPE_BINDING(TYPE_WDT_SBSA, no_fdt_node),
     TYPE_BINDING("", NULL), /* last element */
 };
 
diff --git a/hw/watchdog/sbsa_gwdt.c b/hw/watchdog/sbsa_gwdt.c
index acb970e8b3..c4dd8005b7 100644
--- a/hw/watchdog/sbsa_gwdt.c
+++ b/hw/watchdog/sbsa_gwdt.c
@@ -285,6 +285,7 @@ static void wdt_sbsa_gwdt_class_init(ObjectClass *klass, const void *data)
     dc->realize = wdt_sbsa_gwdt_realize;
     device_class_set_legacy_reset(dc, wdt_sbsa_gwdt_reset);
     dc->hotpluggable = false;
+    dc->user_creatable = true;
     set_bit(DEVICE_CATEGORY_WATCHDOG, dc->categories);
     dc->vmsd = &vmstate_sbsa_gwdt;
     dc->desc = "SBSA-compliant generic watchdog device";
-- 
2.47.3