From: Varun Prakash <varun@chelsio.com>
Date: Wed, 13 Oct 2021 19:54:47 +0530
Subject: scsi: target: cxgbit: Increase max DataSegmentLength
Git-commit: 7f96c7a67e4018317570bb8678e1c44265aba897
Patch-mainline: v5.16-rc1
References: jsc#PED-1509

Current value of max DataSegmentLength is 8K. T5/T6 adapters support
DataSegmentLength upto 16K. Increase max DataSegmentLength.

Link: https://lore.kernel.org/r/1634135087-4996-1-git-send-email-varun@chelsio.com
Signed-off-by: Varun Prakash <varun@chelsio.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Acked-by: Lee Duncan <lduncan@suse.com>
---
 drivers/target/iscsi/cxgbit/cxgbit_main.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/target/iscsi/cxgbit/cxgbit_main.c b/drivers/target/iscsi/cxgbit/cxgbit_main.c
index bd37f2afadea..c6678dc8dd41 100644
--- a/drivers/target/iscsi/cxgbit/cxgbit_main.c
+++ b/drivers/target/iscsi/cxgbit/cxgbit_main.c
@@ -33,11 +33,18 @@ static void cxgbit_set_mdsl(struct cxgbit_device *cdev)
 	struct cxgb4_lld_info *lldi = &cdev->lldi;
 	u32 mdsl;
 
-#define ULP2_MAX_PKT_LEN 16224
-#define ISCSI_PDU_NONPAYLOAD_LEN 312
-	mdsl = min_t(u32, lldi->iscsi_iolen - ISCSI_PDU_NONPAYLOAD_LEN,
-		     ULP2_MAX_PKT_LEN - ISCSI_PDU_NONPAYLOAD_LEN);
-	mdsl = min_t(u32, mdsl, 8192);
+#define CXGBIT_T5_MAX_PDU_LEN 16224
+#define CXGBIT_PDU_NONPAYLOAD_LEN 312 /* 48(BHS) + 256(AHS) + 8(Digest) */
+	if (is_t5(lldi->adapter_type)) {
+		mdsl = min_t(u32, lldi->iscsi_iolen - CXGBIT_PDU_NONPAYLOAD_LEN,
+			     CXGBIT_T5_MAX_PDU_LEN - CXGBIT_PDU_NONPAYLOAD_LEN);
+	} else {
+		mdsl = lldi->iscsi_iolen - CXGBIT_PDU_NONPAYLOAD_LEN;
+		mdsl = min(mdsl, 16384U);
+	}
+
+	mdsl = round_down(mdsl, 4);
+	mdsl = min_t(u32, mdsl, 4 * PAGE_SIZE);
 	mdsl = min_t(u32, mdsl, (MAX_SKB_FRAGS - 1) * PAGE_SIZE);
 
 	cdev->mdsl = mdsl;