[PATCH v2 09/21] 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.

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

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
 hw/arm/Kconfig           |  1 +
 hw/arm/virt-acpi-build.c | 33 +++++++++++++++++++++++++++++++--
 hw/arm/virt.c            |  2 ++
 hw/core/sysbus-fdt.c     | 32 ++++++++++++++++++++++++++++++++
 hw/watchdog/sbsa_gwdt.c  |  1 +
 5 files changed, 67 insertions(+), 2 deletions(-)

diff --git a/hw/arm/Kconfig b/hw/arm/Kconfig
index c66c452737..1222efadd1 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 719d2f994e..9c14b1d4d5 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"
 
 #define ARM_SPI_BASE 32
 
@@ -863,6 +864,8 @@ 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);
 
@@ -893,10 +896,15 @@ 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);
@@ -906,6 +914,27 @@ 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) {
+        PlatformBusDevice *pbus = PLATFORM_BUS_DEVICE(vms->platform_bus_dev);
+        SysBusDevice *sd = SYS_BUS_DEVICE(wdt);
+        hwaddr mmio_base = vms->memmap[VIRT_PLATFORM_BUS].base;
+        hwaddr rbase = mmio_base + platform_bus_get_mmio_addr(pbus, sd, 0);
+        hwaddr cbase = mmio_base + platform_bus_get_mmio_addr(pbus, sd, 1);
+        int irq = ARM_SPI_BASE + vms->irqmap[VIRT_PLATFORM_BUS] +
+                  platform_bus_get_irqn(pbus, sd, 0);
+
+        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 cab2e21e8a..a87991b591 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" },
@@ -3474,6 +3475,7 @@ 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..76aa1bc579 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
@@ -118,6 +119,36 @@ static int add_uefi_vars_node(SysBusDevice *sbdev, void *opaque)
     return 0;
 }
 
+static int add_sbsa_gwdt_node(SysBusDevice *sbdev, void *opaque)
+{
+    PlatformBusFDTData *data = opaque;
+    PlatformBusDevice *pbus = data->pbus;
+    const char *parent_node = data->pbus_node_name;
+    void *fdt = data->fdt;
+    uint64_t cbase, rbase;
+    char *nodename;
+    int irq;
+
+    cbase = platform_bus_get_mmio_addr(pbus, sbdev, 1);  /* control frame */
+    rbase = platform_bus_get_mmio_addr(pbus, sbdev, 0);  /* refresh frame */
+    irq = platform_bus_get_irqn(pbus, sbdev, 0);
+
+    nodename = g_strdup_printf("%s/watchdog@%" PRIx64, parent_node, cbase);
+    qemu_fdt_add_subnode(fdt, nodename);
+
+    qemu_fdt_setprop_string(fdt, nodename, "compatible", "arm,sbsa-gwdt");
+    qemu_fdt_setprop_cells(fdt, nodename, "reg",
+                           cbase, SBSA_GWDT_CMMIO_SIZE,
+                           rbase, SBSA_GWDT_RMMIO_SIZE);
+    qemu_fdt_setprop_cells(fdt, nodename, "interrupts",
+                           GIC_FDT_IRQ_TYPE_SPI, data->irq_start + irq,
+                           GIC_FDT_IRQ_FLAGS_LEVEL_HI);
+    qemu_fdt_setprop_cell(fdt, nodename, "timeout-sec", 30);
+
+    g_free(nodename);
+    return 0;
+}
+
 static int no_fdt_node(SysBusDevice *sbdev, void *opaque)
 {
     return 0;
@@ -140,6 +171,7 @@ 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, add_sbsa_gwdt_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