[libata] Add host lock to struct ata_port

Prepare for changes required to support SATA devices
attached to SAS HBAs. For these devices we don't want to
use host_set at all, since libata will not be the owner
of struct scsi_host.

Signed-off-by: Brian King <brking@us.ibm.com>

(with slight merge modifications made by...)
Signed-off-by: Jeff Garzik <jeff@garzik.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 6b3c3af2c75f..20b1cf527c60 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -483,6 +483,7 @@ struct ata_eh_context {
 struct ata_port {
         struct Scsi_Host        *host;  /* our co-allocated scsi host */
         const struct ata_port_operations *ops;
+        spinlock_t              *lock;
         unsigned long           flags;  /* ATA_FLAG_xxx */
         unsigned int            id;     /* unique id req'd by scsi midlyr */
         unsigned int            port_no; /* unique port #; from zero */