/*

   *  Copyright 2007-2010 Red Hat, Inc.

   *  by Peter Jones <pjones@redhat.com>
   *  Copyright 2007 IBM, Inc.
   *  by Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
   *  Copyright 2008
   *  by Konrad Rzeszutek <ketuzsezr@darnok.org>
   *
   * This code finds the iSCSI Boot Format Table.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License v2.0 as published by
   * the Free Software Foundation
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   */
  
  #include <linux/bootmem.h>
  #include <linux/blkdev.h>
  #include <linux/ctype.h>
  #include <linux/device.h>

  #include <linux/efi.h>

  #include <linux/err.h>
  #include <linux/init.h>
  #include <linux/limits.h>
  #include <linux/module.h>
  #include <linux/pci.h>

  #include <linux/stat.h>
  #include <linux/string.h>
  #include <linux/types.h>

  #include <linux/acpi.h>
  #include <linux/iscsi_ibft.h>

  
  #include <asm/mmzone.h>
  
  /*
   * Physical location of iSCSI Boot Format Table.
   */

  struct acpi_table_ibft *ibft_addr;

  EXPORT_SYMBOL_GPL(ibft_addr);

  static const struct {
  	char *sign;
  } ibft_signs[] = {

  	{ "iBFT" },
  	{ "BIFT" },	/* Broadcom iSCSI Offload */
  };

  #define IBFT_SIGN_LEN 4
  #define IBFT_START 0x80000 /* 512kB */
  #define IBFT_END 0x100000 /* 1MB */
  #define VGA_MEM 0xA0000 /* VGA buffer */
  #define VGA_SIZE 0x20000 /* 128kB */

  static int __init find_ibft_in_mem(void)

  {
  	unsigned long pos;
  	unsigned int len = 0;
  	void *virt;

  	int i;

  	for (pos = IBFT_START; pos < IBFT_END; pos += 16) {
  		/* The table can't be inside the VGA BIOS reserved space,
  		 * so skip that area */
  		if (pos == VGA_MEM)
  			pos += VGA_SIZE;

  		virt = isa_bus_to_virt(pos);

  
  		for (i = 0; i < ARRAY_SIZE(ibft_signs); i++) {
  			if (memcmp(virt, ibft_signs[i].sign, IBFT_SIGN_LEN) ==
  			    0) {
  				unsigned long *addr =
  				    (unsigned long *)isa_bus_to_virt(pos + 4);
  				len = *addr;
  				/* if the length of the table extends past 1M,
  				 * the table cannot be valid. */
  				if (pos + len <= (IBFT_END-1)) {
  					ibft_addr = (struct acpi_table_ibft *)virt;

  					pr_info("iBFT found at 0x%lx.
  ", pos);

  					goto done;
  				}

  			}
  		}
  	}

  done:

  	return len;
  }
  /*
   * Routine used to find the iSCSI Boot Format Table. The logical
   * kernel address is set in the ibft_addr global variable.
   */
  unsigned long __init find_ibft_region(unsigned long *sizep)
  {

  	ibft_addr = NULL;

  	/* iBFT 1.03 section 1.4.3.1 mandates that UEFI machines will
  	 * only use ACPI for this */

  	if (!efi_enabled)

  		find_ibft_in_mem();

  	if (ibft_addr) {

  		*sizep = PAGE_ALIGN(ibft_addr->header.length);
  		return (u64)isa_virt_to_bus(ibft_addr);

  	}
  
  	*sizep = 0;
  	return 0;

  }