1 files changed, 24 insertions, 11 deletions

diff --git a/drivers/fpga/dfl-afu-main.c b/drivers/fpga/dfl-afu-main.c
index 65437b6a6842..b0c31789a909 100644
--- a/drivers/fpga/dfl-afu-main.c
+++ b/drivers/fpga/dfl-afu-main.c
@@ -561,14 +561,16 @@ static int afu_open(struct inode *inode, struct file *filp)
 	if (WARN_ON(!pdata))
 		return -ENODEV;
 
-	ret = dfl_feature_dev_use_begin(pdata);
-	if (ret)
-		return ret;
-
-	dev_dbg(&fdev->dev, "Device File Open\n");
-	filp->private_data = fdev;
+	mutex_lock(&pdata->lock);
+	ret = dfl_feature_dev_use_begin(pdata, filp->f_flags & O_EXCL);
+	if (!ret) {
+		dev_dbg(&fdev->dev, "Device File Opened %d Times\n",
+			dfl_feature_dev_use_count(pdata));
+		filp->private_data = fdev;
+	}
+	mutex_unlock(&pdata->lock);
 
-	return 0;
+	return ret;
 }
 
 static int afu_release(struct inode *inode, struct file *filp)
@@ -581,12 +583,14 @@ static int afu_release(struct inode *inode, struct file *filp)
 	pdata = dev_get_platdata(&pdev->dev);
 
 	mutex_lock(&pdata->lock);
-	__port_reset(pdev);
-	afu_dma_region_destroy(pdata);
-	mutex_unlock(&pdata->lock);
-
 	dfl_feature_dev_use_end(pdata);
 
+	if (!dfl_feature_dev_use_count(pdata)) {
+		__port_reset(pdev);
+		afu_dma_region_destroy(pdata);
+	}
+	mutex_unlock(&pdata->lock);
+
 	return 0;
 }
 
@@ -746,6 +750,12 @@ static long afu_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 	return -EINVAL;
 }
 
+static const struct vm_operations_struct afu_vma_ops = {
+#ifdef CONFIG_HAVE_IOREMAP_PROT
+	.access = generic_access_phys,
+#endif
+};
+
 static int afu_mmap(struct file *filp, struct vm_area_struct *vma)
 {
 	struct platform_device *pdev = filp->private_data;
@@ -775,6 +785,9 @@ static int afu_mmap(struct file *filp, struct vm_area_struct *vma)
 	    !(region.flags & DFL_PORT_REGION_WRITE))
 		return -EPERM;
 
+	/* Support debug access to the mapping */
+	vma->vm_ops = &afu_vma_ops;
+
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 
 	return remap_pfn_range(vma, vma->vm_start,