From: Bart Van Assche <bart.vanassche@wdc.com>
Date: Fri, 15 Jun 2018 14:41:57 -0700
Subject: scsi: mpt3sas: Introduce struct mpt3sas_nvme_cmd
Git-commit: 84203b3561726be0e4c4fbb2db90c9d7e6f59314
Patch-mainline: v4.19-rc1
References: FATE#325922 bsc#1117108

Make _base_build_nvme_prp() easier to read by introducing a structure
to access NVMe command fields.

Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Sathya Prakash <sathya.prakash@broadcom.com>
Cc: Chaitra P B <chaitra.basappa@broadcom.com>
Cc: Suganath Prabu Subramani <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Hannes Reinecke <hare@suse.com>
---
 drivers/scsi/mpt3sas/mpt3sas_base.c | 13 ++++---------
 drivers/scsi/mpt3sas/mpt3sas_base.h |  7 +++++--
 2 files changed, 9 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 3bf9ee7d9603..340db9ee090d 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -1864,6 +1864,8 @@ _base_build_nvme_prp(struct MPT3SAS_ADAPTER *ioc, u16 smid,
 	u32		offset, entry_len;
 	u32		page_mask_result, page_mask;
 	size_t		length;
+	struct mpt3sas_nvme_cmd *nvme_cmd =
+		(void *)nvme_encap_request->NVMe_Command;
 
 	/*
 	 * Not all commands require a data transfer. If no data, just return
@@ -1871,15 +1873,8 @@ _base_build_nvme_prp(struct MPT3SAS_ADAPTER *ioc, u16 smid,
 	 */
 	if (!data_in_sz && !data_out_sz)
 		return;
-	/*
-	 * Set pointers to PRP1 and PRP2, which are in the NVMe command.
-	 * PRP1 is located at a 24 byte offset from the start of the NVMe
-	 * command.  Then set the current PRP entry pointer to PRP1.
-	 */
-	prp1_entry = (__le64 *)(nvme_encap_request->NVMe_Command +
-	    NVME_CMD_PRP1_OFFSET);
-	prp2_entry = (__le64 *)(nvme_encap_request->NVMe_Command +
-	    NVME_CMD_PRP2_OFFSET);
+	prp1_entry = &nvme_cmd->prp1;
+	prp2_entry = &nvme_cmd->prp2;
 	prp_entry = prp1_entry;
 	/*
 	 * For the PRP entries, use the specially allocated buffer of
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h
index b00670a54106..247a9e6c485c 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.h
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.h
@@ -143,14 +143,17 @@
  * NVMe defines
  */
 #define	NVME_PRP_SIZE			8	/* PRP size */
-#define	NVME_CMD_PRP1_OFFSET		24	/* PRP1 offset in NVMe cmd */
-#define	NVME_CMD_PRP2_OFFSET		32	/* PRP2 offset in NVMe cmd */
 #define	NVME_ERROR_RESPONSE_SIZE	16	/* Max NVME Error Response */
 #define NVME_TASK_ABORT_MIN_TIMEOUT	6
 #define NVME_TASK_ABORT_MAX_TIMEOUT	60
 #define NVME_TASK_MNGT_CUSTOM_MASK	(0x0010)
 #define	NVME_PRP_PAGE_SIZE		4096	/* Page size */
 
+struct mpt3sas_nvme_cmd {
+	u8	rsvd[24];
+	__le64	prp1;
+	__le64	prp2;
+};
 
 /*
  * reset phases
-- 
2.16.4