[U-Boot] [PATCH v6 3/8] x86: qemu: add a cpu uclass driver for qemu target

[Miao Yan]

Add a cpu uclass driver for qemu. Previously, the qemu target gets cpu
number from board dts files, which are manually created at compile time.
This does not scale when more cpus are assigned to guest as the dts files
must be modified as well.

This patch adds a cpu uclass driver for qemu targets to directly read
online cpu number from firmware.

Signed-off-by: Miao Yan <yanmiaobest at gmail.com>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
Reviewed-by: Simon Glass <sjg at chromium.org>
---
 arch/x86/cpu/qemu/Makefile       |  2 +-
 arch/x86/cpu/qemu/cpu.c          | 57 ++++++++++++++++++++++++++++++++++++++++
 arch/x86/dts/qemu-x86_i440fx.dts |  4 +--
 arch/x86/dts/qemu-x86_q35.dts    |  4 +--
 4 files changed, 62 insertions(+), 5 deletions(-)
 create mode 100644 arch/x86/cpu/qemu/cpu.c

diff --git a/arch/x86/cpu/qemu/Makefile b/arch/x86/cpu/qemu/Makefile
index d613798..176ea54 100644
--- a/arch/x86/cpu/qemu/Makefile
+++ b/arch/x86/cpu/qemu/Makefile
@@ -7,5 +7,5 @@
 ifndef CONFIG_EFI_STUB
 obj-y += car.o dram.o
 endif
-obj-y += fw_cfg.o qemu.o
+obj-y += cpu.o fw_cfg.o qemu.o
 obj-$(CONFIG_GENERATE_ACPI_TABLE) += acpi.o dsdt.o
diff --git a/arch/x86/cpu/qemu/cpu.c b/arch/x86/cpu/qemu/cpu.c
new file mode 100644
index 0000000..a4bf53d
--- /dev/null
+++ b/arch/x86/cpu/qemu/cpu.c
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2015, Miao Yan <yanmiaobest at gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <cpu.h>
+#include <dm.h>
+#include <errno.h>
+#include <asm/cpu.h>
+#include <asm/fw_cfg.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+int cpu_qemu_bind(struct udevice *dev)
+{
+	struct cpu_platdata *plat = dev_get_parent_platdata(dev);
+
+	plat->cpu_id = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
+				      "intel,apic-id", -1);
+
+	return 0;
+}
+
+int cpu_qemu_get_desc(struct udevice *dev, char *buf, int size)
+{
+	if (size < CPU_MAX_NAME_LEN)
+		return -ENOSPC;
+
+	cpu_get_name(buf);
+
+	return 0;
+}
+
+static int cpu_qemu_get_count(struct udevice *dev)
+{
+	return qemu_fwcfg_online_cpus();
+}
+
+static const struct cpu_ops cpu_qemu_ops = {
+	.get_desc	= cpu_qemu_get_desc,
+	.get_count	= cpu_qemu_get_count,
+};
+
+static const struct udevice_id cpu_qemu_ids[] = {
+	{ .compatible = "cpu-qemu" },
+	{ }
+};
+
+U_BOOT_DRIVER(cpu_qemu_drv) = {
+	.name		= "cpu_qemu",
+	.id		= UCLASS_CPU,
+	.of_match	= cpu_qemu_ids,
+	.bind		= cpu_qemu_bind,
+	.ops		= &cpu_qemu_ops,
+};
diff --git a/arch/x86/dts/qemu-x86_i440fx.dts b/arch/x86/dts/qemu-x86_i440fx.dts
index 8a06229..4332204 100644
--- a/arch/x86/dts/qemu-x86_i440fx.dts
+++ b/arch/x86/dts/qemu-x86_i440fx.dts
@@ -32,14 +32,14 @@
 
 		cpu at 0 {
 			device_type = "cpu";
-			compatible = "cpu-x86";
+			compatible = "cpu-qemu";
 			reg = <0>;
 			intel,apic-id = <0>;
 		};
 
 		cpu at 1 {
 			device_type = "cpu";
-			compatible = "cpu-x86";
+			compatible = "cpu-qemu";
 			reg = <1>;
 			intel,apic-id = <1>;
 		};
diff --git a/arch/x86/dts/qemu-x86_q35.dts b/arch/x86/dts/qemu-x86_q35.dts
index 0b685c8..3e2cfac 100644
--- a/arch/x86/dts/qemu-x86_q35.dts
+++ b/arch/x86/dts/qemu-x86_q35.dts
@@ -43,14 +43,14 @@
 
 		cpu at 0 {
 			device_type = "cpu";
-			compatible = "cpu-x86";
+			compatible = "cpu-qemu";
 			reg = <0>;
 			intel,apic-id = <0>;
 		};
 
 		cpu at 1 {
 			device_type = "cpu";
-			compatible = "cpu-x86";
+			compatible = "cpu-qemu";
 			reg = <1>;
 			intel,apic-id = <1>;
 		};
-- 
1.9.1