scsi: lpfc: Adapt partitioned XRI lists to efficient sharing

The XRI get/put lists were partitioned per hardware queue. However, the
adapter rarely had sufficient resources to give a large number of resources
per queue. As such, it became common for a cpu to encounter a lack of XRI
resource and request the upper io stack to retry after returning a BUSY
condition. This occurred even though other cpus were idle and not using
their resources.

Create as efficient a scheme as possible to move resources to the cpus that
need them. Each cpu maintains a small private pool which it allocates from
for io. There is a watermark that the cpu attempts to keep in the private
pool.  The private pool, when empty, pulls from a global pool from the
cpu. When the cpu's global pool is empty it will pull from other cpu's
global pool. As there many cpu global pools (1 per cpu or hardware queue
count) and as each cpu selects what cpu to pull from at different rates and
at different times, it creates a radomizing effect that minimizes the
number of cpu's that will contend with each other when the steal XRI's from
another cpu's global pool.

On io completion, a cpu will push the XRI back on to its private pool.  A
watermark level is maintained for the private pool such that when it is
exceeded it will move XRI's to the CPU global pool so that other cpu's may
allocate them.

On NVME, as heartbeat commands are critical to get placed on the wire, a
single expedite pool is maintained. When a heartbeat is to be sent, it will
allocate an XRI from the expedite pool rather than the normal cpu
private/global pools. On any io completion, if a reduction in the expedite
pools is seen, it will be replenished before the XRI is placed on the cpu
private pool.

Statistics are added to aid understanding the XRI levels on each cpu and
their behaviors.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 0 insertions, 53 deletions

diff --git a/drivers/scsi/lpfc/lpfc_scsi.h b/drivers/scsi/lpfc/lpfc_scsi.h
index 696898087244..9ee0ea4a1ef2 100644
--- a/drivers/scsi/lpfc/lpfc_scsi.h
+++ b/drivers/scsi/lpfc/lpfc_scsi.h
@@ -130,59 +130,6 @@ struct lpfc_scsicmd_bkt {
 	uint32_t cmd_count;
 };
 
-struct lpfc_scsi_buf {
-	/* Common fields */
-	struct list_head list;
-	void *data;
-	dma_addr_t dma_handle;
-	dma_addr_t dma_phys_sgl;
-	struct ulp_bde64 *dma_sgl;
-	struct lpfc_iocbq cur_iocbq;
-	struct lpfc_sli4_hdw_queue *hdwq;
-	uint16_t hdwq_no;
-	uint16_t cpu;
-
-	/* SCSI specific fields */
-	struct scsi_cmnd *pCmd;
-	struct lpfc_rport_data *rdata;
-	struct lpfc_nodelist *ndlp;
-
-	uint32_t timeout;
-
-	uint16_t flags;  /* TBD convert exch_busy to flags */
-#define LPFC_SBUF_XBUSY		0x1	/* SLI4 hba reported XB on WCQE cmpl */
-#define LPFC_SBUF_BUMP_QDEPTH	0x2	/* bumped queue depth counter */
-	uint16_t exch_busy;     /* SLI4 hba reported XB on complete WCQE */
-	uint16_t status;	/* From IOCB Word 7- ulpStatus */
-	uint32_t result;	/* From IOCB Word 4. */
-
-	uint32_t   seg_cnt;	/* Number of scatter-gather segments returned by
-				 * dma_map_sg.  The driver needs this for calls
-				 * to dma_unmap_sg. */
-	uint32_t prot_seg_cnt;  /* seg_cnt's counterpart for protection data */
-
-	/*
-	 * data and dma_handle are the kernel virtual and bus address of the
-	 * dma-able buffer containing the fcp_cmd, fcp_rsp and a scatter
-	 * gather bde list that supports the sg_tablesize value.
-	 */
-	struct fcp_cmnd *fcp_cmnd;
-	struct fcp_rsp *fcp_rsp;
-
-	wait_queue_head_t *waitq;
-	unsigned long start_time;
-
-#ifdef CONFIG_SCSI_LPFC_DEBUG_FS
-	/* Used to restore any changes to protection data for error injection */
-	void *prot_data_segment;
-	uint32_t prot_data;
-	uint32_t prot_data_type;
-#define	LPFC_INJERR_REFTAG	1
-#define	LPFC_INJERR_APPTAG	2
-#define	LPFC_INJERR_GUARD	3
-#endif
-};
-
 #define LPFC_SCSI_DMA_EXT_SIZE	264
 #define LPFC_BPL_SIZE		1024
 #define MDAC_DIRECT_CMD		0x22