Firmware: add iSCSI iBFT Support

Add /sysfs/firmware/ibft/[initiator|targetX|ethernetX] directories along with
text properties which export the the iSCSI Boot Firmware Table (iBFT)
structure.

What is iSCSI Boot Firmware Table?  It is a mechanism for the iSCSI tools to
extract from the machine NICs the iSCSI connection information so that they
can automagically mount the iSCSI share/target.  Currently the iSCSI
information is hard-coded in the initrd.  The /sysfs entries are read-only
one-name-and-value fields.

The usual set of data exposed is:

# for a in `find /sys/firmware/ibft/ -type f -print`; do  echo -n "$a: ";  cat $a; done
/sys/firmware/ibft/target0/target-name: iqn.2007.com.intel-sbx44:storage-10gb
/sys/firmware/ibft/target0/nic-assoc: 0
/sys/firmware/ibft/target0/chap-type: 0
/sys/firmware/ibft/target0/lun: 00000000
/sys/firmware/ibft/target0/port: 3260
/sys/firmware/ibft/target0/ip-addr: 192.168.79.116
/sys/firmware/ibft/target0/flags: 3
/sys/firmware/ibft/target0/index: 0
/sys/firmware/ibft/ethernet0/mac: 00:11:25:9d:8b:01
/sys/firmware/ibft/ethernet0/vlan: 0
/sys/firmware/ibft/ethernet0/gateway: 192.168.79.254
/sys/firmware/ibft/ethernet0/origin: 0
/sys/firmware/ibft/ethernet0/subnet-mask: 255.255.252.0
/sys/firmware/ibft/ethernet0/ip-addr: 192.168.77.41
/sys/firmware/ibft/ethernet0/flags: 7
/sys/firmware/ibft/ethernet0/index: 0
/sys/firmware/ibft/initiator/initiator-name: iqn.2007-07.com:konrad.initiator
/sys/firmware/ibft/initiator/flags: 3
/sys/firmware/ibft/initiator/index: 0

For full details of the IBFT structure please take a look at:
ftp://ftp.software.ibm.com/systems/support/system_x_pdf/ibm_iscsi_boot_firmware_table_v1.02.pdf

[akpm@linux-foundation.org: fix build]
Signed-off-by: Konrad Rzeszutek <konradr@linux.vnet.ibm.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Cc: Peter Jones <pjones@redhat.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 50 insertions, 0 deletions

diff --git a/include/linux/iscsi_ibft.h b/include/linux/iscsi_ibft.h
new file mode 100644
index 000000000000..6092487e2950
--- /dev/null
+++ b/include/linux/iscsi_ibft.h
@@ -0,0 +1,50 @@
+/*
+ *  Copyright 2007 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 exposes the iSCSI Boot Format Table to userland via sysfs.
+ *
+ * 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.
+ */
+
+#ifndef ISCSI_IBFT_H
+#define ISCSI_IBFT_H
+
+struct ibft_table_header {
+        char signature[4];
+        u32 length;
+        u8 revision;
+        u8 checksum;
+        char oem_id[6];
+        char oem_table_id[8];
+        char reserved[24];
+} __attribute__((__packed__));
+
+/*
+ * Logical location of iSCSI Boot Format Table.
+ * If the value is NULL there is no iBFT on the machine.
+ */
+extern struct ibft_table_header *ibft_addr;
+
+/*
+ * Routine used to find and reserve the iSCSI Boot Format Table. The
+ * mapped address is set in the ibft_addr variable.
+ */
+#ifdef CONFIG_ISCSI_IBFT_FIND
+extern void __init reserve_ibft_region(void);
+#else
+static inline void reserve_ibft_region(void) { }
+#endif
+
+#endif /* ISCSI_IBFT_H */