[PATCH] hw/riscv: virt: Generate fw_cfg DT node correctly

[Atish Patra <atishp@rivosinc.com>]

fw_cfg DT node is generated after the create_fdt without any check
if the DT is being loaded from the commandline. This results in
FDT_ERR_EXISTS error if dtb is loaded from the commandline.

Generate fw_cfg node only if the DT is not loaded from the commandline.

Signed-off-by: Atish Patra <atishp@rivosinc.com>
---
 hw/riscv/virt.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/hw/riscv/virt.c b/hw/riscv/virt.c
index c57617381517..07aeee3bf0c3 100644
--- a/hw/riscv/virt.c
+++ b/hw/riscv/virt.c
@@ -975,6 +975,23 @@ static void create_fdt_flash(RISCVVirtState *s, const MemMapEntry *memmap)
     g_free(name);
 }
 
+static void create_fdt_fw_cfg(RISCVVirtState *s, const MemMapEntry *memmap)
+{
+    char *nodename;
+    MachineState *mc = MACHINE(s);
+    hwaddr base = memmap[VIRT_FW_CFG].base;
+    hwaddr size = memmap[VIRT_FW_CFG].size;
+
+    nodename = g_strdup_printf("/fw-cfg@%" PRIx64, base);
+    qemu_fdt_add_subnode(mc->fdt, nodename);
+    qemu_fdt_setprop_string(mc->fdt, nodename,
+                            "compatible", "qemu,fw-cfg-mmio");
+    qemu_fdt_setprop_sized_cells(mc->fdt, nodename, "reg",
+                                 2, base, 2, size);
+    qemu_fdt_setprop(mc->fdt, nodename, "dma-coherent", NULL, 0);
+    g_free(nodename);
+}
+
 static void create_fdt(RISCVVirtState *s, const MemMapEntry *memmap,
                        uint64_t mem_size, const char *cmdline, bool is_32_bit)
 {
@@ -1023,6 +1040,7 @@ static void create_fdt(RISCVVirtState *s, const MemMapEntry *memmap,
     create_fdt_rtc(s, memmap, irq_mmio_phandle);
 
     create_fdt_flash(s, memmap);
+    create_fdt_fw_cfg(s, memmap);
 
 update_bootargs:
     if (cmdline && *cmdline) {
@@ -1082,22 +1100,12 @@ static inline DeviceState *gpex_pcie_init(MemoryRegion *sys_mem,
 static FWCfgState *create_fw_cfg(const MachineState *mc)
 {
     hwaddr base = virt_memmap[VIRT_FW_CFG].base;
-    hwaddr size = virt_memmap[VIRT_FW_CFG].size;
     FWCfgState *fw_cfg;
-    char *nodename;
 
     fw_cfg = fw_cfg_init_mem_wide(base + 8, base, 8, base + 16,
                                   &address_space_memory);
     fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)mc->smp.cpus);
 
-    nodename = g_strdup_printf("/fw-cfg@%" PRIx64, base);
-    qemu_fdt_add_subnode(mc->fdt, nodename);
-    qemu_fdt_setprop_string(mc->fdt, nodename,
-                            "compatible", "qemu,fw-cfg-mmio");
-    qemu_fdt_setprop_sized_cells(mc->fdt, nodename, "reg",
-                                 2, base, 2, size);
-    qemu_fdt_setprop(mc->fdt, nodename, "dma-coherent", NULL, 0);
-    g_free(nodename);
     return fw_cfg;
 }
 
-- 
2.25.1