x86: qemu: add fw_cfg support

The QEMU fw_cfg interface allows the guest to retrieve various data
information from QEMU. For example, APCI/SMBios tables, number of online
cpus, kernel data and command line, etc.

This patch adds support for QEMU fw_cfg interface.

Signed-off-by: Miao Yan <yanmiaobest@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Tested-by: Bin Meng <bmeng.cn@gmail.com>

1 files changed, 93 insertions, 0 deletions

diff --git a/arch/x86/include/asm/fw_cfg.h b/arch/x86/include/asm/fw_cfg.h
new file mode 100644
index 0000000000..fb110fa8e7
--- /dev/null
+++ b/arch/x86/include/asm/fw_cfg.h
@@ -0,0 +1,93 @@
+/*
+ * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __FW_CFG__
+#define __FW_CFG__
+
+#define FW_CONTROL_PORT	0x510
+#define FW_DATA_PORT		0x511
+#define FW_DMA_PORT_LOW	0x514
+#define FW_DMA_PORT_HIGH	0x518
+
+enum qemu_fwcfg_items {
+	FW_CFG_SIGNATURE	= 0x00,
+	FW_CFG_ID		= 0x01,
+	FW_CFG_UUID		= 0x02,
+	FW_CFG_RAM_SIZE		= 0x03,
+	FW_CFG_NOGRAPHIC	= 0x04,
+	FW_CFG_NB_CPUS		= 0x05,
+	FW_CFG_MACHINE_ID	= 0x06,
+	FW_CFG_KERNEL_ADDR	= 0x07,
+	FW_CFG_KERNEL_SIZE	= 0x08,
+	FW_CFG_KERNEL_CMDLINE   = 0x09,
+	FW_CFG_INITRD_ADDR	= 0x0a,
+	FW_CFG_INITRD_SIZE	= 0x0b,
+	FW_CFG_BOOT_DEVICE	= 0x0c,
+	FW_CFG_NUMA		= 0x0d,
+	FW_CFG_BOOT_MENU	= 0x0e,
+	FW_CFG_MAX_CPUS		= 0x0f,
+	FW_CFG_KERNEL_ENTRY	= 0x10,
+	FW_CFG_KERNEL_DATA	= 0x11,
+	FW_CFG_INITRD_DATA	= 0x12,
+	FW_CFG_CMDLINE_ADDR	= 0x13,
+	FW_CFG_CMDLINE_SIZE	= 0x14,
+	FW_CFG_CMDLINE_DATA	= 0x15,
+	FW_CFG_SETUP_ADDR	= 0x16,
+	FW_CFG_SETUP_SIZE	= 0x17,
+	FW_CFG_SETUP_DATA	= 0x18,
+	FW_CFG_FILE_DIR		= 0x19,
+	FW_CFG_FILE_FIRST	= 0x20,
+	FW_CFG_WRITE_CHANNEL	= 0x4000,
+	FW_CFG_ARCH_LOCAL	= 0x8000,
+	FW_CFG_INVALID		= 0xffff,
+};
+
+#define FW_CFG_FILE_SLOTS	0x10
+#define FW_CFG_MAX_ENTRY	(FW_CFG_FILE_FIRST + FW_CFG_FILE_SLOTS)
+#define FW_CFG_ENTRY_MASK	 ~(FW_CFG_WRITE_CHANNEL | FW_CFG_ARCH_LOCAL)
+
+#define FW_CFG_MAX_FILE_PATH	56
+
+#define QEMU_FW_CFG_SIGNATURE	(('Q' << 24) | ('E' << 16) | ('M' << 8) | 'U')
+
+#define FW_CFG_DMA_ERROR	(1 << 0)
+#define FW_CFG_DMA_READ	(1 << 1)
+#define FW_CFG_DMA_SKIP	(1 << 2)
+#define FW_CFG_DMA_SELECT	(1 << 3)
+
+#define FW_CFG_DMA_ENABLED	(1 << 1)
+
+struct fw_cfg_file {
+	__be32 size;
+	__be16 select;
+	__be16 reserved;
+	char name[FW_CFG_MAX_FILE_PATH];
+};
+
+struct fw_cfg_files {
+	__be32 count;
+	struct fw_cfg_file files[];
+};
+
+struct fw_cfg_dma_access {
+	__be32 control;
+	__be32 length;
+	__be64 address;
+};
+
+/**
+ * Initialize QEMU fw_cfg interface
+ */
+void qemu_fwcfg_init(void);
+
+/**
+ * Get system cpu number
+ *
+ * @return:   cpu number in system
+ */
+int qemu_fwcfg_online_cpus(void);
+
+#endif