diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
index aad060aa3c0c0c65c92e0dceb96628d3286b77ec..acef7d6a5790b754115427145b6a32b96cbac1fa 100644
--- a/drivers/scsi/pm8001/pm8001_init.c
+++ b/drivers/scsi/pm8001/pm8001_init.c
@@ -246,6 +246,7 @@ static int pm8001_alloc(struct pm8001_hba_info *pm8001_ha,
 {
 	int i;
 	spin_lock_init(&pm8001_ha->lock);
+	spin_lock_init(&pm8001_ha->bitmap_lock);
 	PM8001_INIT_DBG(pm8001_ha,
 		pm8001_printk("pm8001_alloc: PHY:%x\n",
 				pm8001_ha->chip->n_phy));
diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
index be55859042cdd83c0b4cee4722f9282931f33de9..34cea82917722fbe9ad0a295f31d37638d7cf308 100644
--- a/drivers/scsi/pm8001/pm8001_sas.c
+++ b/drivers/scsi/pm8001/pm8001_sas.c
@@ -77,11 +77,16 @@ inline int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
 {
 	unsigned int tag;
 	void *bitmap = pm8001_ha->tags;
+	unsigned long flags;
 
+	spin_lock_irqsave(&pm8001_ha->bitmap_lock, flags);
 	tag = find_first_zero_bit(bitmap, pm8001_ha->tags_num);
-	if (tag >= pm8001_ha->tags_num)
+	if (tag >= pm8001_ha->tags_num) {
+		spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
 		return -SAS_QUEUE_FULL;
+	}
 	set_bit(tag, bitmap);
+	spin_unlock_irqrestore(&pm8001_ha->bitmap_lock, flags);
 	*tag_out = tag;
 	return 0;
 }
diff --git a/drivers/scsi/pm8001/pm8001_sas.h b/drivers/scsi/pm8001/pm8001_sas.h
index 14106adec00949621945520173833b424e151eed..f6b2ac59dae4f66dd99c1455cf7674e6113eb5bc 100644
--- a/drivers/scsi/pm8001/pm8001_sas.h
+++ b/drivers/scsi/pm8001/pm8001_sas.h
@@ -475,6 +475,7 @@ struct pm8001_hba_info {
 	struct list_head	list;
 	unsigned long		flags;
 	spinlock_t		lock;/* host-wide lock */
+	spinlock_t		bitmap_lock;
 	struct pci_dev		*pdev;/* our device */
 	struct device		*dev;
 	struct pm8001_hba_memspace io_mem[6];