/*
   * (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
   *
   * SPDX-License-Identifier:	GPL-2.0+
   */
  
  #ifndef __FW_CFG__
  #define __FW_CFG__

  #include <linux/list.h>

  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,
  };

  enum {
  	BIOS_LINKER_LOADER_COMMAND_ALLOCATE	= 0x1,
  	BIOS_LINKER_LOADER_COMMAND_ADD_POINTER  = 0x2,
  	BIOS_LINKER_LOADER_COMMAND_ADD_CHECKSUM = 0x3,
  };
  
  enum {
  	BIOS_LINKER_LOADER_ALLOC_ZONE_HIGH = 0x1,
  	BIOS_LINKER_LOADER_ALLOC_ZONE_FSEG = 0x2,
  };

  #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 BIOS_LINKER_LOADER_FILESZ FW_CFG_MAX_FILE_PATH

  
  #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_file {
  	struct fw_cfg_file cfg; /* firmware file information */
  	unsigned long addr;     /* firmware file in-memory address */
  	struct list_head list;  /* list node to link to fw_list */

  };

  struct fw_cfg_file_iter {
  	struct list_head *entry; /* structure to iterate file list */
  };

  struct fw_cfg_dma_access {
  	__be32 control;
  	__be32 length;
  	__be64 address;
  };

  struct fw_cfg_arch_ops {
  	void (*arch_read_pio)(uint16_t selector, uint32_t size,
  			void *address);
  	void (*arch_read_dma)(struct fw_cfg_dma_access *dma);
  };

  struct bios_linker_entry {
  	__le32 command;
  	union {
  		/*
  		 * COMMAND_ALLOCATE - allocate a table from @alloc.file
  		 * subject to @alloc.align alignment (must be power of 2)
  		 * and @alloc.zone (can be HIGH or FSEG) requirements.
  		 *
  		 * Must appear exactly once for each file, and before
  		 * this file is referenced by any other command.
  		 */
  		struct {
  			char file[BIOS_LINKER_LOADER_FILESZ];
  			__le32 align;
  			uint8_t zone;
  		} alloc;
  
  		/*
  		 * COMMAND_ADD_POINTER - patch the table (originating from
  		 * @dest_file) at @pointer.offset, by adding a pointer to the
  		 * table originating from @src_file. 1,2,4 or 8 byte unsigned
  		 * addition is used depending on @pointer.size.
  		 */
  		struct {
  			char dest_file[BIOS_LINKER_LOADER_FILESZ];
  			char src_file[BIOS_LINKER_LOADER_FILESZ];
  			__le32 offset;
  			uint8_t size;
  		} pointer;
  
  		/*
  		 * COMMAND_ADD_CHECKSUM - calculate checksum of the range
  		 * specified by @cksum_start and @cksum_length fields,
  		 * and then add the value at @cksum.offset.
  		 * Checksum simply sums -X for each byte X in the range
  		 * using 8-bit math.
  		 */
  		struct {
  			char file[BIOS_LINKER_LOADER_FILESZ];
  			__le32 offset;
  			__le32 start;
  			__le32 length;
  		} cksum;
  
  		/* padding */
  		char pad[124];
  	};
  } __packed;

  /**
   * Initialize QEMU fw_cfg interface

   *
   * @ops: arch specific read operations

   */

  void qemu_fwcfg_init(struct fw_cfg_arch_ops *ops);

  void qemu_fwcfg_read_entry(uint16_t entry, uint32_t length, void *address);
  int qemu_fwcfg_read_firmware_list(void);
  struct fw_file *qemu_fwcfg_find_file(const char *name);

  /**
   * Get system cpu number
   *
   * @return:   cpu number in system
   */
  int qemu_fwcfg_online_cpus(void);

  /* helper functions to iterate firmware file list */
  struct fw_file *qemu_fwcfg_file_iter_init(struct fw_cfg_file_iter *iter);
  struct fw_file *qemu_fwcfg_file_iter_next(struct fw_cfg_file_iter *iter);
  bool qemu_fwcfg_file_iter_end(struct fw_cfg_file_iter *iter);

  bool qemu_fwcfg_present(void);
  bool qemu_fwcfg_dma_present(void);

  #endif