scsi: mpt3sas: lockless command submission

Performance improvement using block layer tag.

Curent driver gets scsiio tracker and free smid from link list and array
based tracking managed by driver.  Accessing list in main io path is
performance pentaly because of protection using spinlock
"scsi_lookup_lock".

In this patch:

1. Driver removes all link list access from main io path and
   use scmd->request->tag to get free smid.

2. Instead of holding 'struct scsiio_tracker' in its own pool
   driver can embed it into the scsi command.

Driver provides cmd_size in scsi_host_template, so that struct
scsiio_tracker is preallocated by scsi mid layer for each scsi command.

Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 9 insertions, 16 deletions

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h
index 58ac9238f47e..789bc421424b 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.h
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.h
@@ -772,20 +772,17 @@ struct chain_tracker {
 /**
  * struct scsiio_tracker - scsi mf request tracker
  * @smid: system message id
- * @scmd: scsi request pointer
  * @cb_idx: callback index
  * @direct_io: To indicate whether I/O is direct (WARPDRIVE)
- * @tracker_list: list of free request (ioc->free_list)
+ * @chain_list: list of associated firmware chain tracker
  * @msix_io: IO's msix
  */
 struct scsiio_tracker {
 	u16	smid;
-	struct scsi_cmnd *scmd;
 	u8	cb_idx;
 	u8	direct_io;
 	struct pcie_sg_list pcie_sg_list;
 	struct list_head chain_list;
-	struct list_head tracker_list;
 	u16     msix_io;
 };
 
@@ -1248,10 +1245,8 @@ struct MPT3SAS_ADAPTER {
 	u8		*request;
 	dma_addr_t	request_dma;
 	u32		request_dma_sz;
-	struct scsiio_tracker *scsi_lookup;
-	ulong		scsi_lookup_pages;
+	struct pcie_sg_list *pcie_sg_lookup;
 	spinlock_t	scsi_lookup_lock;
-	struct list_head free_list;
 	int		pending_io_count;
 	wait_queue_head_t reset_wq;
 
@@ -1270,6 +1265,7 @@ struct MPT3SAS_ADAPTER {
 	u16		chains_needed_per_io;
 	u32		chain_depth;
 	u16		chain_segment_sz;
+	u16		chains_per_prp_buffer;
 
 	/* hi-priority queue */
 	u16		hi_priority_smid;
@@ -1401,9 +1397,9 @@ void mpt3sas_base_sync_reply_irqs(struct MPT3SAS_ADAPTER *ioc);
 /* hi-priority queue */
 u16 mpt3sas_base_get_smid_hpr(struct MPT3SAS_ADAPTER *ioc, u8 cb_idx);
 u16 mpt3sas_base_get_smid_scsiio(struct MPT3SAS_ADAPTER *ioc, u8 cb_idx,
-	struct scsi_cmnd *scmd);
-struct scsiio_tracker *mpt3sas_get_st_from_smid(struct MPT3SAS_ADAPTER *ioc,
-	u16 smid);
+		struct scsi_cmnd *scmd);
+void mpt3sas_base_clear_st(struct MPT3SAS_ADAPTER *ioc,
+		struct scsiio_tracker *st);
 
 u16 mpt3sas_base_get_smid(struct MPT3SAS_ADAPTER *ioc, u8 cb_idx);
 void mpt3sas_base_free_smid(struct MPT3SAS_ADAPTER *ioc, u16 smid);
@@ -1439,6 +1435,8 @@ int mpt3sas_port_enable(struct MPT3SAS_ADAPTER *ioc);
 
 
 /* scsih shared API */
+struct scsi_cmnd *mpt3sas_scsih_scsi_lookup_get(struct MPT3SAS_ADAPTER *ioc,
+	u16 smid);
 u8 mpt3sas_scsih_event_callback(struct MPT3SAS_ADAPTER *ioc, u8 msix_index,
 	u32 reply);
 void mpt3sas_scsih_reset_handler(struct MPT3SAS_ADAPTER *ioc, int reset_phase);
@@ -1613,14 +1611,9 @@ void mpt3sas_trigger_mpi(struct MPT3SAS_ADAPTER *ioc, u16 ioc_status,
 u8 mpt3sas_get_num_volumes(struct MPT3SAS_ADAPTER *ioc);
 void mpt3sas_init_warpdrive_properties(struct MPT3SAS_ADAPTER *ioc,
 	struct _raid_device *raid_device);
-u8
-mpt3sas_scsi_direct_io_get(struct MPT3SAS_ADAPTER *ioc, u16 smid);
-void
-mpt3sas_scsi_direct_io_set(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 direct_io);
 void
 mpt3sas_setup_direct_io(struct MPT3SAS_ADAPTER *ioc, struct scsi_cmnd *scmd,
-	struct _raid_device *raid_device, Mpi25SCSIIORequest_t *mpi_request,
-	u16 smid);
+	struct _raid_device *raid_device, Mpi25SCSIIORequest_t *mpi_request);
 
 /* NCQ Prio Handling Check */
 bool scsih_ncq_prio_supp(struct scsi_device *sdev);