From 2b477bd7193aaa29f3423429417b39ae6fce650a Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Sun, 13 Jan 2019 21:27:19 +0000
Subject: [PATCH] scst: Port to Linux kernel v5.0 (merge r7849 from trunk)

git-svn-id: http://svn.code.sf.net/p/scst/svn/branches/3.3.x@7888 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 qla2x00t/qla_iocb.c     |  2 +-
 qla2x00t/qla_os.c       |  5 ++++-
 scst/include/backport.h | 14 ++++++++++++++
 scst/src/scst_lib.c     | 12 +++++++++++-
 scst_local/scst_local.c |  5 +++++
 5 files changed, 35 insertions(+), 3 deletions(-)

diff --git a/qla2x00t/qla_iocb.c b/qla2x00t/qla_iocb.c
index 37e0bdbd9..fe327ea4f 100644
--- a/qla2x00t/qla_iocb.c
+++ b/qla2x00t/qla_iocb.c
@@ -1875,7 +1875,7 @@ static void qla25xx_set_que(srb_t *sp, struct rsp_que **rsp)
 {
 	struct scsi_cmnd *cmd = GET_CMD_SP(sp);
 	struct qla_hw_data *ha = sp->fcport->vha->hw;
-	int affinity = cmd->request->cpu;
+	int affinity = scst_blk_rq_cpu(cmd->request);
 
 	if (ha->flags.cpu_affinity_enabled && affinity >= 0 &&
 		affinity < ha->max_rsp_queues - 1)
diff --git a/qla2x00t/qla_os.c b/qla2x00t/qla_os.c
index a565b8719..f9ebba662 100644
--- a/qla2x00t/qla_os.c
+++ b/qla2x00t/qla_os.c
@@ -304,7 +304,9 @@ struct scsi_host_template qla2xxx_driver_template = {
 #endif
 	.this_id		= -1,
 	.cmd_per_lun		= 3,
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 21, 0)
 	.use_clustering		= ENABLE_CLUSTERING,
+#endif
 	.sg_tablesize		= SG_ALL,
 
 	.max_sectors		= 0xFFFF,
@@ -1160,7 +1162,8 @@ __qla2xxx_eh_generic_reset(char *name, enum nexus_wait_type type,
 		goto eh_reset_failed;
 	}
 	err = 2;
-	if (do_reset(fcport, cmd->device->lun, cmd->request->cpu + 1)
+	if (do_reset(fcport, cmd->device->lun,
+		     scst_blk_rq_cpu(cmd->request) + 1)
 		!= QLA_SUCCESS) {
 		ql_log(ql_log_warn, vha, 0x800c,
 		    "do_reset failed for cmd=%p.\n", cmd);
diff --git a/scst/include/backport.h b/scst/include/backport.h
index b5b9d033b..f2db11483 100644
--- a/scst/include/backport.h
+++ b/scst/include/backport.h
@@ -22,6 +22,9 @@
 
 #include <linux/bio.h>
 #include <linux/blkdev.h>	/* struct request_queue */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 21, 0)
+#include <linux/blk-mq.h>
+#endif
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(3, 1, 0)
 #include <linux/bsg-lib.h>	/* struct bsg_job */
 #endif
@@ -116,6 +119,17 @@ static inline unsigned int queue_max_hw_sectors(struct request_queue *q)
 }
 #endif
 
+/* <linux/blk-mq.h> */
+
+static inline unsigned int scst_blk_rq_cpu(struct request *rq)
+{
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 21, 0)
+	return rq->cpu;
+#else
+	return blk_mq_rq_cpu(rq);
+#endif
+}
+
 /* <linux/bsg-lib.h> */
 
 /*
diff --git a/scst/src/scst_lib.c b/scst/src/scst_lib.c
index 3e55e290b..85351c44f 100644
--- a/scst/src/scst_lib.c
+++ b/scst/src/scst_lib.c
@@ -5281,7 +5281,12 @@ static int scst_alloc_add_tgt_dev(struct scst_session *sess,
 
 		ini_sg = shost->sg_tablesize;
 		ini_unchecked_isa_dma = shost->unchecked_isa_dma;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 21, 0)
 		ini_use_clustering = shost->use_clustering == ENABLE_CLUSTERING;
+#else
+		ini_use_clustering = !(shost->dma_boundary == PAGE_SIZE - 1 &&
+				       shost->max_segment_size == PAGE_SIZE);
+#endif
 	} else {
 		ini_sg = (1 << 15) /* infinite */;
 		ini_unchecked_isa_dma = 0;
@@ -8398,7 +8403,7 @@ static void scsi_end_async(struct request *req, blk_status_t error)
 
 #if LINUX_VERSION_CODE < KERNEL_VERSION(3, 17, 0)
 	lockdep_assert_held(req->q->queue_lock);
-#else
+#elif LINUX_VERSION_CODE < KERNEL_VERSION(4, 21, 0)
 	if (!req->q->mq_ops)
 		lockdep_assert_held(req->q->queue_lock);
 #endif
@@ -8429,7 +8434,12 @@ static void scsi_end_async(struct request *req, blk_status_t error)
 
 	kmem_cache_free(scsi_io_context_cache, sioc);
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 21, 0)
+	/* See also commit 92bc5a24844a ("block: remove __blk_put_request()") */
 	__blk_put_request(req->q, req);
+#else
+	blk_put_request(req);
+#endif
 	return;
 }
 
diff --git a/scst_local/scst_local.c b/scst_local/scst_local.c
index 2d0e5aab2..1be668940 100644
--- a/scst_local/scst_local.c
+++ b/scst_local/scst_local.c
@@ -1663,7 +1663,12 @@ static struct scsi_host_template scst_lcl_ini_driver_template = {
 	.sg_tablesize			= 0xFFFF,
 	.max_sectors			= 0xffff,
 	/* Possible pass-through backend device may not support clustering */
+#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 21, 0)
 	.use_clustering			= DISABLE_CLUSTERING,
+#else
+	.dma_boundary			= PAGE_SIZE - 1,
+	.max_segment_size		= PAGE_SIZE,
+#endif
 	.skip_settle_delay		= 1,
 	.module				= THIS_MODULE,
 };