hw/loongarch: Add fw_cfg table support

Add fw_cfg table for loongarch virt machine, including memmap table.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Xiaojuan Yang <yangxiaojuan@loongson.cn>
Message-Id: <20220712083206.4187715-2-yangxiaojuan@loongson.cn>
[rth: Replace fprintf with assert; drop unused return value;
      initialize reserved slot to zero.]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

hw/loongarch/fw_cfg.c

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * QEMU fw_cfg helpers (LoongArch specific)
+ *
+ * Copyright (C) 2021 Loongson Technology Corporation Limited
+ */
+
+#include "qemu/osdep.h"
+#include "hw/loongarch/fw_cfg.h"
+#include "hw/loongarch/virt.h"
+#include "hw/nvram/fw_cfg.h"
+#include "sysemu/sysemu.h"
+
+static void fw_cfg_boot_set(void *opaque, const char *boot_device,
+                            Error **errp)
+{
+    fw_cfg_modify_i16(opaque, FW_CFG_BOOT_DEVICE, boot_device[0]);
+}
+
+FWCfgState *loongarch_fw_cfg_init(ram_addr_t ram_size, MachineState *ms)
+{
+    FWCfgState *fw_cfg;
+    int max_cpus = ms->smp.max_cpus;
+    int smp_cpus = ms->smp.cpus;
+
+    fw_cfg = fw_cfg_init_mem_wide(VIRT_FWCFG_BASE + 8, VIRT_FWCFG_BASE, 8, 0, NULL);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_MAX_CPUS, (uint16_t)max_cpus);
+    fw_cfg_add_i64(fw_cfg, FW_CFG_RAM_SIZE, (uint64_t)ram_size);
+    fw_cfg_add_i16(fw_cfg, FW_CFG_NB_CPUS, (uint16_t)smp_cpus);
+
+    qemu_register_boot_set(fw_cfg_boot_set, fw_cfg);
+    return fw_cfg;
+}

hw/loongarch/fw_cfg.h

+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * QEMU fw_cfg helpers (LoongArch specific)
+ *
+ * Copyright (C) 2021 Loongson Technology Corporation Limited
+ */
+
+#ifndef HW_LOONGARCH_FW_CFG_H
+#define HW_LOONGARCH_FW_CFG_H
+
+#include "hw/boards.h"
+#include "hw/nvram/fw_cfg.h"
+
+FWCfgState *loongarch_fw_cfg_init(ram_addr_t ram_size, MachineState *ms);
+#endif

hw/loongarch/loongson3.c

@@ -28,13 +28,40 @@
 #include "hw/pci-host/ls7a.h"
 #include "hw/pci-host/gpex.h"
 #include "hw/misc/unimp.h"
-
+#include "hw/loongarch/fw_cfg.h"
 #include "target/loongarch/cpu.h"
 
 #define PM_BASE 0x10080000
 #define PM_SIZE 0x100
 #define PM_CTRL 0x10
 
+struct memmap_entry {
+    uint64_t address;
+    uint64_t length;
+    uint32_t type;
+    uint32_t reserved;
+};
+
+static struct memmap_entry *memmap_table;
+static unsigned memmap_entries;
+
+static void memmap_add_entry(uint64_t address, uint64_t length, uint32_t type)
+{
+    /* Ensure there are no duplicate entries. */
+    for (unsigned i = 0; i < memmap_entries; i++) {
+        assert(memmap_table[i].address != address);
+    }
+
+    memmap_table = g_renew(struct memmap_entry, memmap_table,
+                           memmap_entries + 1);
+    memmap_table[memmap_entries].address = cpu_to_le64(address);
+    memmap_table[memmap_entries].length = cpu_to_le64(length);
+    memmap_table[memmap_entries].type = cpu_to_le32(type);
+    memmap_table[memmap_entries].reserved = 0;
+    memmap_entries++;
+}
+
+
 /*
  * This is a placeholder for missing ACPI,
  * and will eventually be replaced.
@@ -331,15 +358,27 @@ static void loongarch_init(MachineState *machine)
                              machine->ram, 0, 256 * MiB);
     memory_region_add_subregion(address_space_mem, offset, &lams->lowmem);
     offset += 256 * MiB;
+    memmap_add_entry(0, 256 * MiB, 1);
     highram_size = ram_size - 256 * MiB;
     memory_region_init_alias(&lams->highmem, NULL, "loongarch.highmem",
                              machine->ram, offset, highram_size);
     memory_region_add_subregion(address_space_mem, 0x90000000, &lams->highmem);
+    memmap_add_entry(0x90000000, highram_size, 1);
     /* Add isa io region */
     memory_region_init_alias(&lams->isa_io, NULL, "isa-io",
                              get_system_io(), 0, LOONGARCH_ISA_IO_SIZE);
     memory_region_add_subregion(address_space_mem, LOONGARCH_ISA_IO_BASE,
                                 &lams->isa_io);
+    /* 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));
+    }
+
     if (kernel_filename) {
         loaderparams.ram_size = ram_size;
         loaderparams.kernel_filename = kernel_filename;

hw/loongarch/meson.build

 loongarch_ss = ss.source_set()
+loongarch_ss.add(files(
+    'fw_cfg.c',
+))
 loongarch_ss.add(when: 'CONFIG_LOONGARCH_VIRT', if_true: files('loongson3.c'))
 
 hw_arch += {'loongarch': loongarch_ss}

include/hw/loongarch/virt.h

@@ -17,6 +17,7 @@
 
 #define LOONGARCH_ISA_IO_BASE   0x18000000UL
 #define LOONGARCH_ISA_IO_SIZE   0x0004000
+#define VIRT_FWCFG_BASE         0x1e020000UL
 
 struct LoongArchMachineState {
     /*< private >*/
@@ -26,6 +27,8 @@ struct LoongArchMachineState {
     MemoryRegion lowmem;
     MemoryRegion highmem;
     MemoryRegion isa_io;
+    /* State for other subsystems/APIs: */
+    FWCfgState  *fw_cfg;
 };
 
 #define TYPE_LOONGARCH_MACHINE  MACHINE_TYPE_NAME("virt")