[PATCH v3 07/17] arm: virt: add support for WDAT based watchdog

[Igor Mammedov <imammedo@redhat.com>]

Add WDAT handling for sbsa-gwdt on arm/virt machine.

WDAT mode is enabled by 'wdat' option: ex: "-device sbsa-gwdt,wdat=on"

When WDAT is enabled:
 - Build the WDAT ACPI table instead of the GTDT watchdog entry,
   since they are mutually exclusive due to different timer
   resolution (WDAT uses 1 kHz vs GTDT's system counter frequency).
 - Skip FDT watchdog node creation, as the DT-based Linux driver
   would use the system counter frequency which doesn't match the
   WDAT-mode 1 kHz clock.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
---
v3:
   - Skip FDT watchdog node creation in wdat mode
   (Eric)
     - wiring part of larger '[PATCH v2 11/21] arm: virt: add support for WDAT based watchdog'
---
 hw/arm/virt-acpi-build.c | 34 ++++++++++++++++++++++++++--------
 hw/arm/virt.c            | 10 ++++++----
 2 files changed, 32 insertions(+), 12 deletions(-)

diff --git a/hw/arm/virt-acpi-build.c b/hw/arm/virt-acpi-build.c
index f5b3b4ce48..71706b98e6 100644
--- a/hw/arm/virt-acpi-build.c
+++ b/hw/arm/virt-acpi-build.c
@@ -65,6 +65,7 @@
 #include "target/arm/cpu.h"
 #include "target/arm/multiprocessing.h"
 #include "hw/watchdog/sbsa_gwdt.h"
+#include "hw/acpi/wdat-gwdt.h"
 
 #include "smmuv3-accel.h"
 #include "tegra241-cmdqv.h"
@@ -859,7 +860,8 @@ build_srat(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
  * 5.2.25 Generic Timer Description Table (GTDT)
  */
 static void
-build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
+build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms,
+           Object *wdt, bool add_watchdog)
 {
     /*
      * Table 5-117 Flag Definitions
@@ -870,7 +872,6 @@ build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     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);
 
@@ -903,12 +904,12 @@ build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     build_append_int_noprefix(table_data, 0xFFFFFFFFFFFFFFFF, 8);
 
     /* Platform Timer Count */
-    build_append_int_noprefix(table_data,  wdt ? 1 : 0, 4);
+    build_append_int_noprefix(table_data,  add_watchdog ? 1 : 0, 4);
     /* Platform Timer Offset */
     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);
+        add_watchdog ? (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 */
@@ -921,7 +922,7 @@ build_gtdt(GArray *table_data, BIOSLinker *linker, VirtMachineState *vms)
     }
 
     /* ACPI 6.5 spec: 5.2.25.2 ARM Generic Watchdog Structure (Table 5-124) */
-    if (wdt) {
+    if (add_watchdog) {
         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];
@@ -1332,13 +1333,19 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
     VirtMachineClass *vmc = VIRT_MACHINE_GET_CLASS(vms);
     GArray *table_offsets;
     unsigned dsdt, xsdt;
+    bool has_wdat = false;
     GArray *tables_blob = tables->table_data;
     MachineState *ms = MACHINE(vms);
     CPUCoreCaches caches[CPU_MAX_CACHES];
     unsigned int num_caches;
+    Object *wdt = object_resolve_type_unambiguous(TYPE_WDT_SBSA, NULL);
 
     num_caches = virt_get_caches(vms, caches);
 
+    if (wdt) {
+        has_wdat = object_property_get_bool(wdt, "wdat", &error_abort);
+    }
+
     table_offsets = g_array_new(false, true /* clear */,
                                         sizeof(uint32_t));
 
@@ -1357,6 +1364,17 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
     acpi_add_table(table_offsets, tables_blob);
     build_madt(tables_blob, tables->linker, vms);
 
+    acpi_add_table(table_offsets, tables_blob);
+    if (wdt && has_wdat) {
+        uint64_t freq = object_property_get_uint(wdt, "clock-frequency",
+                                                 &error_abort);
+        build_gwdt_wdat(tables_blob, tables->linker,
+                        vms->oem_id, vms->oem_table_id,
+                        vms->memmap[VIRT_GWDT_REFRESH].base,
+                        vms->memmap[VIRT_GWDT_CONTROL].base,
+                        freq);
+    }
+
     if (!vmc->no_cpu_topology) {
         acpi_add_table(table_offsets, tables_blob);
         build_pptt(tables_blob, tables->linker, ms, vms->oem_id,
@@ -1364,7 +1382,7 @@ void virt_acpi_build(VirtMachineState *vms, AcpiBuildTables *tables)
     }
 
     acpi_add_table(table_offsets, tables_blob);
-    build_gtdt(tables_blob, tables->linker, vms);
+    build_gtdt(tables_blob, tables->linker, vms, wdt, wdt && !has_wdat);
 
     acpi_add_table(table_offsets, tables_blob);
     {
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index aacf9b7251..35ded6d1d4 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -3825,9 +3825,11 @@ static void virt_machine_device_pre_plug_cb(HotplugHandler *hotplug_dev,
         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);
+        if (!object_property_get_bool(OBJECT(dev), "wdat", &error_abort)) {
+            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. "
@@ -3890,7 +3892,7 @@ static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
         sysbus_mmio_map(s, 1, cbase);
         sysbus_connect_irq(s, 0, qdev_get_gpio_in(vms->gic, irq));
 
-        {
+        if (!object_property_get_bool(OBJECT(dev), "wdat", &error_abort)) {
             char *nodename = g_strdup_printf("/watchdog@%" PRIx64, cbase);
 
             qemu_fdt_add_subnode(ms->fdt, nodename);
-- 
2.47.3