[SCSI] add supported_mode and active_mode attributes to the host

This adds supported_mode and active_mode attributes to
/sys/class/sys_host/hostX/ for specifying the mode that a lld supports
and the currently activated mode. The output format is similar to fc
rport roles:

luce:/sys/class/scsi_host/host0$ cat supported_mode
Initiator
luce:/sys/class/scsi_host/host0$ cat active_mode
Initiator

The mode values uses bitmap since we would support dual-mode llds in
the future like this:

luce:/sys/class/scsi_host/host0$ cat supported_mode
Initiator, Target

The supported_mode attribute looks at a scsi_host_template and the
active_mode attribute looks at a scsi_host. We would add a hook to a
scsi_host_template to change the active_mode attribute
dynamically. But now there is no hook since no lld supports that
feature.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 88f6871badd8..5b79697a3a80 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -32,6 +32,9 @@ struct blk_queue_tags;
 #define SG_NONE 0
 #define SG_ALL 0xff
 
+#define MODE_UNKNOWN 0x00
+#define MODE_INITIATOR 0x01
+#define MODE_TARGET 0x02
 
 #define DISABLE_CLUSTERING 0
 #define ENABLE_CLUSTERING 1
@@ -405,6 +408,11 @@ struct scsi_host_template {
         unsigned char present;
 
         /*
+         * This specifies the mode that a LLD supports.
+         */
+        unsigned supported_mode:2;
+
+        /*
          * true if this host adapter uses unchecked DMA onto an ISA bus.
          */
         unsigned unchecked_isa_dma:1;
@@ -574,6 +582,7 @@ struct Scsi_Host {
          */
         unsigned long cmd_serial_number, cmd_pid; 
         
+        unsigned active_mode:2;
         unsigned unchecked_isa_dma:1;
         unsigned use_clustering:1;
         unsigned use_blk_tcq:1;