From 5a694056febfd5ee20677475cd4968c8e728c19c Mon Sep 17 00:00:00 2001
From: Miao Yan <yanmiaobest@gmail.com>
Date: Thu, 7 Jan 2016 01:32:01 -0800
Subject: [PATCH] x86: qemu: add a cpu uclass driver for qemu target

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@gmail.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Bin Meng <bmeng.cn@gmail.com>
---
 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 d613798da13..176ea54ae4e 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 00000000000..a4bf53dacef
--- /dev/null
+++ b/arch/x86/cpu/qemu/cpu.c
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2015, Miao Yan <yanmiaobest@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 8a062294798..433220475dc 100644
--- a/arch/x86/dts/qemu-x86_i440fx.dts
+++ b/arch/x86/dts/qemu-x86_i440fx.dts
@@ -32,14 +32,14 @@
 
 		cpu@0 {
 			device_type = "cpu";
-			compatible = "cpu-x86";
+			compatible = "cpu-qemu";
 			reg = <0>;
 			intel,apic-id = <0>;
 		};
 
 		cpu@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 0b685c8b799..3e2cfac5031 100644
--- a/arch/x86/dts/qemu-x86_q35.dts
+++ b/arch/x86/dts/qemu-x86_q35.dts
@@ -43,14 +43,14 @@
 
 		cpu@0 {
 			device_type = "cpu";
-			compatible = "cpu-x86";
+			compatible = "cpu-qemu";
 			reg = <0>;
 			intel,apic-id = <0>;
 		};
 
 		cpu@1 {
 			device_type = "cpu";
-			compatible = "cpu-x86";
+			compatible = "cpu-qemu";
 			reg = <1>;
 			intel,apic-id = <1>;
 		};
-- 
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