Eric Lee / smarc-fsl-linux-kernel

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drivers/firmware/iscsi_ibft_find.c 2.77 KB
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81f7e3824   Eric Lee   Initial Release, ... 
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  /*
   *  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(EFI_BOOT))
  		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;
  }