libsas: remove task_collector mode

The task_collector mode (or "latency_injector", (C) Dan Willians) is an
optional I/O path in libsas that queues up scsi commands instead of
directly sending it to the hardware.  It generall increases latencies
to in the optiomal case slightly reduce mmio traffic to the hardware.

Only the obsolete aic94xx driver and the mvsas driver allowed to use
it without recompiling the kernel, and most drivers didn't support it
at all.

Remove the giant blob of code to allow better optimizations for scsi-mq
in the future.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 1 insertions, 13 deletions

diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index 1f8b33ec612f..832dcc9f86ec 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -365,12 +365,6 @@ struct asd_sas_phy {
 struct scsi_core {
         struct Scsi_Host *shost;
 
-        struct mutex      task_queue_flush;
-        spinlock_t        task_queue_lock;
-        struct list_head  task_queue;
-        int               task_queue_size;
-
-        struct task_struct *queue_thread;
 };
 
 struct sas_ha_event {
@@ -422,9 +416,6 @@ struct sas_ha_struct {
         struct asd_sas_port **sas_port; /* array of valid pointers, must be set */
         int             num_phys; /* must be set, gt 0, static */
 
-        /* The class calls this to send a task for execution. */
-        int lldd_max_execute_num;
-        int lldd_queue_size;
         int strict_wide_ports; /* both sas_addr and attached_sas_addr must match
                                 * their siblings when forming wide ports */
 
@@ -612,7 +603,6 @@ struct sas_ssp_task {
 
 struct sas_task {
         struct domain_device *dev;
-        struct list_head      list;
 
         spinlock_t   task_state_lock;
         unsigned     task_state_flags;
@@ -665,8 +655,7 @@ struct sas_domain_function_template {
         int  (*lldd_dev_found)(struct domain_device *);
         void (*lldd_dev_gone)(struct domain_device *);
 
-        int (*lldd_execute_task)(struct sas_task *, int num,
-                                 gfp_t gfp_flags);
+        int (*lldd_execute_task)(struct sas_task *, gfp_t gfp_flags);
 
         /* Task Management Functions. Must be called from process context. */
         int (*lldd_abort_task)(struct sas_task *);
@@ -700,7 +689,6 @@ extern void sas_suspend_ha(struct sas_ha_struct *sas_ha);
 int sas_set_phy_speed(struct sas_phy *phy,
                       struct sas_phy_linkrates *rates);
 int sas_phy_reset(struct sas_phy *phy, int hard_reset);
-int sas_queue_up(struct sas_task *task);
 extern int sas_queuecommand(struct Scsi_Host * ,struct scsi_cmnd *);
 extern int sas_target_alloc(struct scsi_target *);
 extern int sas_slave_configure(struct scsi_device *);