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authorFUJITA Tomonori <tomof@acm.org>2007-10-16 11:24:32 +0200
committerJens Axboe <jens.axboe@oracle.com>2007-10-16 11:24:32 +0200
commit9cb83c7529d929c00f37d821daed1942a1b20602 (patch)
treebb2fded1c443b1c370bdbe27076b62dc66eeddf2 /include/scsi
parentc0dcffd71d5064efefa620231152c38eca8e066b (diff)
[SCSI] add use_sg_chaining option to scsi_host_template
This option is true if a low-level driver can support sg chaining. This will be removed eventually when all the drivers are converted to support sg chaining. q->max_phys_segments is set to SCSI_MAX_SG_SEGMENTS if false. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Diffstat (limited to 'include/scsi')
-rw-r--r--include/scsi/scsi_host.h13
1 files changed, 13 insertions, 0 deletions
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 7d210cd6c38..0fd4746ee39 100644
--- 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+ * Status: OBSOLETE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