hw/loongarch: virt: support up to 4 serial ports

In order to support additional channels of communication using
`-serial`, add several serial ports, up to the standard 4 generally
supported by the 8250 driver.

Fixed: https://lore.kernel.org/all/20240907143439.2792924-1-Jason@zx2c4.com/

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Tested-by: Bibo Mao <maobibo@loongson.cn>
[gaosong: ACPI uart need't reverse order]
Signed-off-by: Song Gao <gaosong@loongson.cn>
Message-Id: <20240907143439.2792924-1-Jason@zx2c4.com>

1 files changed, 17 insertions, 10 deletions

diff --git a/hw/loongarch/virt.c b/hw/loongarch/virt.c
index 29040422aa..76dd29a391 100644
--- a/hw/loongarch/virt.c
+++ b/hw/loongarch/virt.c
@@ -280,10 +280,10 @@ static void fdt_add_rtc_node(LoongArchVirtMachineState *lvms,
 }
 
 static void fdt_add_uart_node(LoongArchVirtMachineState *lvms,
-                              uint32_t *pch_pic_phandle)
+                              uint32_t *pch_pic_phandle, hwaddr base,
+                              int irq, bool chosen)
 {
     char *nodename;
-    hwaddr base = VIRT_UART_BASE;
     hwaddr size = VIRT_UART_SIZE;
     MachineState *ms = MACHINE(lvms);
 
@@ -292,9 +292,9 @@ static void fdt_add_uart_node(LoongArchVirtMachineState *lvms,
     qemu_fdt_setprop_string(ms->fdt, nodename, "compatible", "ns16550a");
     qemu_fdt_setprop_cells(ms->fdt, nodename, "reg", 0x0, base, 0x0, size);
     qemu_fdt_setprop_cell(ms->fdt, nodename, "clock-frequency", 100000000);
-    qemu_fdt_setprop_string(ms->fdt, "/chosen", "stdout-path", nodename);
-    qemu_fdt_setprop_cells(ms->fdt, nodename, "interrupts",
-                           VIRT_UART_IRQ - VIRT_GSI_BASE, 0x4);
+    if (chosen)
+        qemu_fdt_setprop_string(ms->fdt, "/chosen", "stdout-path", nodename);
+    qemu_fdt_setprop_cells(ms->fdt, nodename, "interrupts", irq, 0x4);
     qemu_fdt_setprop_cell(ms->fdt, nodename, "interrupt-parent",
                           *pch_pic_phandle);
     g_free(nodename);
@@ -706,11 +706,18 @@ static void virt_devices_init(DeviceState *pch_pic,
     /* Add pcie node */
     fdt_add_pcie_node(lvms, pch_pic_phandle, pch_msi_phandle);
 
-    serial_mm_init(get_system_memory(), VIRT_UART_BASE, 0,
-                   qdev_get_gpio_in(pch_pic,
-                                    VIRT_UART_IRQ - VIRT_GSI_BASE),
-                   115200, serial_hd(0), DEVICE_LITTLE_ENDIAN);
-    fdt_add_uart_node(lvms, pch_pic_phandle);
+    /*
+     * Create uart fdt node in reverse order so that they appear
+     * in the finished device tree lowest address first
+     */
+    for (i = VIRT_UART_COUNT; i --> 0;) {
+        hwaddr base = VIRT_UART_BASE + i * VIRT_UART_SIZE;
+        int irq = VIRT_UART_IRQ + i - VIRT_GSI_BASE;
+        serial_mm_init(get_system_memory(), base, 0,
+                       qdev_get_gpio_in(pch_pic, irq),
+                       115200, serial_hd(i), DEVICE_LITTLE_ENDIAN);
+        fdt_add_uart_node(lvms, pch_pic_phandle, base, irq, i == 0);
+    }
 
     /* Network init */
     pci_init_nic_devices(pci_bus, mc->default_nic);