[SCSI] add use_sg_chaining option to scsi_host_template

[safe/jmp/linux-2.6] / include / scsi / scsi_host.h

diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 7d210cd..0fd4746 100644 (file)
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -39,6 +39,9 @@ struct blk_queue_tags;
 #define DISABLE_CLUSTERING 0
 #define ENABLE_CLUSTERING 1
 
+#define DISABLE_SG_CHAINING 0
+#define ENABLE_SG_CHAINING 1
+
 enum scsi_eh_timer_return {
        EH_NOT_HANDLED,
        EH_HANDLED,
@@ -443,6 +446,15 @@ struct scsi_host_template {
        unsigned ordered_tag:1;
 
        /*
+        * true if the low-level driver can support sg chaining. this
+        * will be removed eventually when all the drivers are
+        * converted to support sg chaining.
+        *
+        * Status: OBSOLETE
+        */
+       unsigned use_sg_chaining:1;
+
+       /*
         * Countdown for host blocking with no commands outstanding
         */
        unsigned int max_host_blocked;
@@ -586,6 +598,7 @@ struct Scsi_Host {
        unsigned unchecked_isa_dma:1;
        unsigned use_clustering:1;
        unsigned use_blk_tcq:1;
+       unsigned use_sg_chaining:1;
 
        /*
         * Host has requested that no further requests come through for the