hw/loongarch: Add fdt support

Add LoongArch flatted device tree, adding cpu device node, firmware cfg node,
pcie node into it, and create fdt rom memory region. Now fdt info is not
full since only uefi bios uses fdt, linux kernel does not use fdt.
Loongarch Linux kernel uses acpi table which is full in qemu virt
machine.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Message-Id: <20220712083206.4187715-7-yangxiaojuan@loongson.cn>
[rth: Set TARGET_NEED_FDT, add fdt to meson.build]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

configs/targets/loongarch64-softmmu.mak

@@ -2,3 +2,4 @@ TARGET_ARCH=loongarch64
 TARGET_BASE_ARCH=loongarch
 TARGET_SUPPORTS_MTTCG=y
 TARGET_XML_FILES= gdb-xml/loongarch-base64.xml gdb-xml/loongarch-fpu64.xml
+TARGET_NEED_FDT=y

hw/loongarch/loongson3.c

@@ -35,6 +35,129 @@
 #include "qapi/qapi-visit-common.h"
 #include "hw/acpi/generic_event_device.h"
 #include "hw/mem/nvdimm.h"
+#include "sysemu/device_tree.h"
+#include <libfdt.h>
+
+static void create_fdt(LoongArchMachineState *lams)
+{
+    MachineState *ms = MACHINE(lams);
+
+    ms->fdt = create_device_tree(&lams->fdt_size);
+    if (!ms->fdt) {
+        error_report("create_device_tree() failed");
+        exit(1);
+    }
+
+    /* Header */
+    qemu_fdt_setprop_string(ms->fdt, "/", "compatible",
+                            "linux,dummy-loongson3");
+    qemu_fdt_setprop_cell(ms->fdt, "/", "#address-cells", 0x2);
+    qemu_fdt_setprop_cell(ms->fdt, "/", "#size-cells", 0x2);
+}
+
+static void fdt_add_cpu_nodes(const LoongArchMachineState *lams)
+{
+    int num;
+    const MachineState *ms = MACHINE(lams);
+    int smp_cpus = ms->smp.cpus;
+
+    qemu_fdt_add_subnode(ms->fdt, "/cpus");
+    qemu_fdt_setprop_cell(ms->fdt, "/cpus", "#address-cells", 0x1);
+    qemu_fdt_setprop_cell(ms->fdt, "/cpus", "#size-cells", 0x0);
+
+    /* cpu nodes */
+    for (num = smp_cpus - 1; num >= 0; num--) {
+        char *nodename = g_strdup_printf("/cpus/cpu@%d", num);
+        LoongArchCPU *cpu = LOONGARCH_CPU(qemu_get_cpu(num));
+
+        qemu_fdt_add_subnode(ms->fdt, nodename);
+        qemu_fdt_setprop_string(ms->fdt, nodename, "device_type", "cpu");
+        qemu_fdt_setprop_string(ms->fdt, nodename, "compatible",
+                                cpu->dtb_compatible);
+        qemu_fdt_setprop_cell(ms->fdt, nodename, "reg", num);
+        qemu_fdt_setprop_cell(ms->fdt, nodename, "phandle",
+                              qemu_fdt_alloc_phandle(ms->fdt));
+        g_free(nodename);
+    }
+
+    /*cpu map */
+    qemu_fdt_add_subnode(ms->fdt, "/cpus/cpu-map");
+
+    for (num = smp_cpus - 1; num >= 0; num--) {
+        char *cpu_path = g_strdup_printf("/cpus/cpu@%d", num);
+        char *map_path;
+
+        if (ms->smp.threads > 1) {
+            map_path = g_strdup_printf(
+                "/cpus/cpu-map/socket%d/core%d/thread%d",
+                num / (ms->smp.cores * ms->smp.threads),
+                (num / ms->smp.threads) % ms->smp.cores,
+                num % ms->smp.threads);
+        } else {
+            map_path = g_strdup_printf(
+                "/cpus/cpu-map/socket%d/core%d",
+                num / ms->smp.cores,
+                num % ms->smp.cores);
+        }
+        qemu_fdt_add_path(ms->fdt, map_path);
+        qemu_fdt_setprop_phandle(ms->fdt, map_path, "cpu", cpu_path);
+
+        g_free(map_path);
+        g_free(cpu_path);
+    }
+}
+
+static void fdt_add_fw_cfg_node(const LoongArchMachineState *lams)
+{
+    char *nodename;
+    hwaddr base = VIRT_FWCFG_BASE;
+    const MachineState *ms = MACHINE(lams);
+
+    nodename = g_strdup_printf("/fw_cfg@%" PRIx64, base);
+    qemu_fdt_add_subnode(ms->fdt, nodename);
+    qemu_fdt_setprop_string(ms->fdt, nodename,
+                            "compatible", "qemu,fw-cfg-mmio");
+    qemu_fdt_setprop_sized_cells(ms->fdt, nodename, "reg",
+                                 2, base, 2, 0x8);
+    qemu_fdt_setprop(ms->fdt, nodename, "dma-coherent", NULL, 0);
+    g_free(nodename);
+}
+
+static void fdt_add_pcie_node(const LoongArchMachineState *lams)
+{
+    char *nodename;
+    hwaddr base_mmio = LS7A_PCI_MEM_BASE;
+    hwaddr size_mmio = LS7A_PCI_MEM_SIZE;
+    hwaddr base_pio = LS7A_PCI_IO_BASE;
+    hwaddr size_pio = LS7A_PCI_IO_SIZE;
+    hwaddr base_pcie = LS_PCIECFG_BASE;
+    hwaddr size_pcie = LS_PCIECFG_SIZE;
+    hwaddr base = base_pcie;
+
+    const MachineState *ms = MACHINE(lams);
+
+    nodename = g_strdup_printf("/pcie@%" PRIx64, base);
+    qemu_fdt_add_subnode(ms->fdt, nodename);
+    qemu_fdt_setprop_string(ms->fdt, nodename,
+                            "compatible", "pci-host-ecam-generic");
+    qemu_fdt_setprop_string(ms->fdt, nodename, "device_type", "pci");
+    qemu_fdt_setprop_cell(ms->fdt, nodename, "#address-cells", 3);
+    qemu_fdt_setprop_cell(ms->fdt, nodename, "#size-cells", 2);
+    qemu_fdt_setprop_cell(ms->fdt, nodename, "linux,pci-domain", 0);
+    qemu_fdt_setprop_cells(ms->fdt, nodename, "bus-range", 0,
+                           PCIE_MMCFG_BUS(LS_PCIECFG_SIZE - 1));
+    qemu_fdt_setprop(ms->fdt, nodename, "dma-coherent", NULL, 0);
+    qemu_fdt_setprop_sized_cells(ms->fdt, nodename, "reg",
+                                 2, base_pcie, 2, size_pcie);
+    qemu_fdt_setprop_sized_cells(ms->fdt, nodename, "ranges",
+                                 1, FDT_PCI_RANGE_IOPORT, 2, LS7A_PCI_IO_OFFSET,
+                                 2, base_pio, 2, size_pio,
+                                 1, FDT_PCI_RANGE_MMIO, 2, base_mmio,
+                                 2, base_mmio, 2, size_mmio);
+    g_free(nodename);
+    qemu_fdt_dumpdtb(ms->fdt, lams->fdt_size);
+}
+
 
 #define PM_BASE 0x10080000
 #define PM_SIZE 0x100
@@ -524,12 +647,12 @@ static void loongarch_init(MachineState *machine)
         error_report("ram_size must be greater than 1G.");
         exit(1);
     }
-
+    create_fdt(lams);
     /* Init CPUs */
     for (i = 0; i < machine->smp.cpus; i++) {
         cpu_create(machine->cpu_type);
     }
-
+    fdt_add_cpu_nodes(lams);
     /* Add memory region */
     memory_region_init_alias(&lams->lowmem, NULL, "loongarch.lowram",
                              machine->ram, 0, 256 * MiB);
@@ -552,12 +675,12 @@ static void loongarch_init(MachineState *machine)
     /* fw_cfg init */
     lams->fw_cfg = loongarch_fw_cfg_init(ram_size, machine);
     rom_set_fw(lams->fw_cfg);
-
     if (lams->fw_cfg != NULL) {
         fw_cfg_add_file(lams->fw_cfg, "etc/memmap",
                         memmap_table,
                         sizeof(struct memmap_entry) * (memmap_entries));
     }
+    fdt_add_fw_cfg_node(lams);
     loaderparams.ram_size = ram_size;
     loaderparams.kernel_filename = machine->kernel_filename;
     loaderparams.kernel_cmdline = machine->kernel_cmdline;
@@ -579,6 +702,13 @@ static void loongarch_init(MachineState *machine)
     loongarch_irq_init(lams);
     lams->machine_done.notify = virt_machine_done;
     qemu_add_machine_init_done_notifier(&lams->machine_done);
+    fdt_add_pcie_node(lams);
+
+    /* load fdt */
+    MemoryRegion *fdt_rom = g_new(MemoryRegion, 1);
+    memory_region_init_rom(fdt_rom, NULL, "fdt", LA_FDT_SIZE, &error_fatal);
+    memory_region_add_subregion(get_system_memory(), LA_FDT_BASE, fdt_rom);
+    rom_add_blob_fixed("fdt", machine->fdt, lams->fdt_size, LA_FDT_BASE);
 }
 
 bool loongarch_is_acpi_enabled(LoongArchMachineState *lams)

hw/loongarch/meson.build

@@ -2,7 +2,7 @@ loongarch_ss = ss.source_set()
 loongarch_ss.add(files(
     'fw_cfg.c',
 ))
-loongarch_ss.add(when: 'CONFIG_LOONGARCH_VIRT', if_true: files('loongson3.c'))
+loongarch_ss.add(when: 'CONFIG_LOONGARCH_VIRT', if_true: [files('loongson3.c'), fdt])
 loongarch_ss.add(when: 'CONFIG_ACPI', if_true: files('acpi-build.c'))
 
 hw_arch += {'loongarch': loongarch_ss}

include/hw/loongarch/virt.h

@@ -28,6 +28,9 @@
 #define VIRT_GED_MEM_ADDR       (VIRT_GED_EVT_ADDR + ACPI_GED_EVT_SEL_LEN)
 #define VIRT_GED_REG_ADDR       (VIRT_GED_MEM_ADDR + MEMORY_HOTPLUG_IO_LEN)
 
+#define LA_FDT_BASE             0x1c400000
+#define LA_FDT_SIZE             0x100000
+
 struct LoongArchMachineState {
     /*< private >*/
     MachineState parent_obj;
@@ -45,6 +48,7 @@ struct LoongArchMachineState {
     char         *oem_id;
     char         *oem_table_id;
     DeviceState  *acpi_ged;
+    int          fdt_size;
 };
 
 #define TYPE_LOONGARCH_MACHINE  MACHINE_TYPE_NAME("virt")

target/loongarch/cpu.c

@@ -341,6 +341,7 @@ static void loongarch_la464_initfn(Object *obj)
         env->cpucfg[i] = 0x0;
     }
 
+    cpu->dtb_compatible = "loongarch,Loongson-3A5000";
     env->cpucfg[0] = 0x14c010;  /* PRID */
 
     uint32_t data = 0;

target/loongarch/cpu.h

@@ -326,6 +326,9 @@ struct ArchCPU {
     CPUNegativeOffsetState neg;
     CPULoongArchState env;
     QEMUTimer timer;
+
+    /* 'compatible' string for this CPU for Linux device trees */
+    const char *dtb_compatible;
 };
 
 #define TYPE_LOONGARCH_CPU "loongarch-cpu"