From 0c1d1f8c98f5531b8236124011a4b1bf137f752c Mon Sep 17 00:00:00 2001
From: Bart Van Assche <bvanassche@acm.org>
Date: Sun, 31 Mar 2019 16:26:45 +0000
Subject: [PATCH] qla2x00t-32gbit, target: Backport to kernel v3.11 and before

Note: this code has not yet been tested.


git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@8115 d57e44dd-8a1f-0410-8b47-8ef2f437770f
---
 qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.c | 20 +++++++++++++++----
 qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.h |  4 +++-
 qla2x00t-32gbit/qla_target.h                  |  7 +++++++
 3 files changed, 26 insertions(+), 5 deletions(-)

diff --git a/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.c b/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.c
index 2533374a3..6e3d7d6ee 100644
--- a/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.c
+++ b/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.c
@@ -445,7 +445,7 @@ static void sqa_qla2xxx_rel_cmd(struct qla_tgt_cmd *cmd)
 	sbitmap_queue_clear(&sqa_tgt->tgt_tag_pool, cmd->se_cmd.map_tag,
 			    cmd->se_cmd.map_cpu);
 #else
-#error Neither percpu_ida nor sbitmap are available.
+	clear_bit(cmd->map_tag, sqa_tgt->tgt_tag_pool);
 #endif
 }
 
@@ -463,7 +463,16 @@ static struct qla_tgt_cmd *sqa_qla2xxx_get_cmd(struct fc_port *sess)
 
 	tag = sbitmap_queue_get(&sqa_tgt->tgt_tag_pool, &cpu);
 #else
-#error Neither percpu_ida nor sbitmap are available.
+	for (;;) {
+		tag = find_first_zero_bit(sqa_tgt->tgt_tag_pool,
+					  sqa_tgt->tag_num);
+		if (test_and_set_bit(tag, sqa_tgt->tgt_tag_pool) == 0)
+			break;
+		if (tag >= sqa_tgt->tag_num) {
+			tag = -ENOENT;
+			break;
+		}
+	}
 #endif
 	if (tag < 0)
 		return NULL;
@@ -1464,10 +1473,13 @@ static int sqa_init_scst_tgt(struct scsi_qla_host *vha)
 	res = sbitmap_queue_init_node(&sqa_tgt->tgt_tag_pool, tag_num, -1,
 				      false, GFP_KERNEL, NUMA_NO_NODE);
 #else
-#error Neither percpu_ida nor sbitmap are available.
+	sqa_tgt->tag_num = tag_num;
+	sqa_tgt->tgt_tag_pool = kzalloc(BITS_TO_LONGS(tag_num), GFP_KERNEL);
+	res = IS_ERR(sqa_tgt->tgt_tag_pool) ? PTR_ERR(sqa_tgt->tgt_tag_pool) :
+		0;
 #endif
 	if (res < 0) {
-		pr_err("Unable to init se_sess->sess_tag_pool,"
+		pr_err("Unable to init se_sess->tgt_tag_pool,"
 			   " tag_num: %u\n", tag_num);
 		kvfree(sqa_tgt->tgt_cmd_map);
 		kfree(pwwn);
diff --git a/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.h b/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.h
index 8848cc871..2350cf5c8 100644
--- a/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.h
+++ b/qla2x00t-32gbit/qla2x00-target/scst_qla2xxx.h
@@ -3,6 +3,7 @@
 	!(defined(RHEL_MAJOR) && RHEL_MAJOR -0 >= 7)
 #define QLT_USE_PERCPU_IDA 0
 #define QLT_USE_SBITMAP 0
+#include <linux/bitmap.h>
 #elif LINUX_VERSION_CODE < KERNEL_VERSION(4, 19, 0)
 #define QLT_USE_PERCPU_IDA 1
 #define QLT_USE_SBITMAP 0
@@ -30,6 +31,7 @@ struct sqa_scst_tgt{
 #elif QLT_USE_SBITMAP
 	struct sbitmap_queue tgt_tag_pool;
 #else
-#error Neither percpu_ida nor sbitmap are available.
+	unsigned long *tgt_tag_pool;
+	unsigned int tag_num;
 #endif
 };
diff --git a/qla2x00t-32gbit/qla_target.h b/qla2x00t-32gbit/qla_target.h
index 3414c203d..8ec9d7741 100644
--- a/qla2x00t-32gbit/qla_target.h
+++ b/qla2x00t-32gbit/qla_target.h
@@ -899,6 +899,13 @@ struct qla_tgt_cmd {
 	uint8_t cmd_type;
 	uint8_t pad[7];
 	struct se_cmd se_cmd;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 12, 0)
+	/*
+	 * Used if neither <linux/bitmap.h> nor <linux/percpu_ida.h> are
+	 * available.
+	 */
+	unsigned int map_tag;
+#endif
 #if !HAVE_SE_CMD_TAG
 	u64 tag;
 #endif