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Diffstat (limited to 'include/scsi/scsi_host.h')
-rw-r--r--include/scsi/scsi_host.h33
1 files changed, 32 insertions, 1 deletions
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index f5a243261236..e87cf7eadd26 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -87,6 +87,12 @@ struct scsi_host_template {
int (* queuecommand)(struct Scsi_Host *, struct scsi_cmnd *);
/*
+ * Queue a reserved command (BLK_MQ_REQ_RESERVED). The .queuecommand()
+ * documentation also applies to the .queue_reserved_command() callback.
+ */
+ int (*queue_reserved_command)(struct Scsi_Host *, struct scsi_cmnd *);
+
+ /*
* The commit_rqs function is used to trigger a hardware
* doorbell after some requests have been queued with
* queuecommand, when an error is encountered before sending
@@ -375,11 +381,20 @@ struct scsi_host_template {
/*
* This determines if we will use a non-interrupt driven
* or an interrupt driven scheme. It is set to the maximum number
- * of simultaneous commands a single hw queue in HBA will accept.
+ * of simultaneous commands a single hw queue in HBA will accept
+ * excluding internal commands.
*/
int can_queue;
/*
+ * This determines how many commands the HBA will set aside
+ * for internal commands. This number will be added to
+ * @can_queue to calculate the maximum number of simultaneous
+ * commands sent to the host.
+ */
+ int nr_reserved_cmds;
+
+ /*
* In many instances, especially where disconnect / reconnect are
* supported, our host also has an ID on the SCSI bus. If this is
* the case, then it must be reserved. Please set this_id to -1 if
@@ -611,7 +626,17 @@ struct Scsi_Host {
unsigned short max_cmd_len;
int this_id;
+
+ /*
+ * Number of commands this host can handle at the same time.
+ * This excludes reserved commands as specified by nr_reserved_cmds.
+ */
int can_queue;
+ /*
+ * Number of reserved commands to allocate, if any.
+ */
+ unsigned int nr_reserved_cmds;
+
short cmd_per_lun;
short unsigned int sg_tablesize;
short unsigned int sg_prot_tablesize;
@@ -703,6 +728,12 @@ struct Scsi_Host {
struct device shost_gendev, shost_dev;
/*
+ * A SCSI device structure used for sending internal commands to the
+ * HBA. There is no corresponding logical unit inside the SCSI device.
+ */
+ struct scsi_device *pseudo_sdev;
+
+ /*
* Points to the transport data (if any) which is allocated
* separately
*/