1 files changed, 27 insertions, 1 deletions
diff --git a/lib/test_hmm.c b/lib/test_hmm.c
index e2ce8f9b7605..cfe632047839 100644
--- a/lib/test_hmm.c
+++ b/lib/test_hmm.c
@@ -12,6 +12,7 @@
 #include <linux/kernel.h>
 #include <linux/cdev.h>
 #include <linux/device.h>
+#include <linux/memremap.h>
 #include <linux/mutex.h>
 #include <linux/rwsem.h>
 #include <linux/sched.h>
@@ -26,6 +27,8 @@
 #include <linux/sched/mm.h>
 #include <linux/platform_device.h>
 #include <linux/rmap.h>
+#include <linux/mmu_notifier.h>
+#include <linux/migrate.h>
 
 #include "test_hmm_uapi.h"
 
@@ -563,7 +566,6 @@ static struct page *dmirror_devmem_alloc_page(struct dmirror_device *mdevice)
 	}
 
 	dpage->zone_device_data = rpage;
-	get_page(dpage);
 	lock_page(dpage);
 	return dpage;
 
@@ -1086,9 +1088,33 @@ static long dmirror_fops_unlocked_ioctl(struct file *filp,
 	return 0;
 }
 
+static int dmirror_fops_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	unsigned long addr;
+
+	for (addr = vma->vm_start; addr < vma->vm_end; addr += PAGE_SIZE) {
+		struct page *page;
+		int ret;
+
+		page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+		if (!page)
+			return -ENOMEM;
+
+		ret = vm_insert_page(vma, addr, page);
+		if (ret) {
+			__free_page(page);
+			return ret;
+		}
+		put_page(page);
+	}
+
+	return 0;
+}
+
 static const struct file_operations dmirror_fops = {
 	.open		= dmirror_fops_open,
 	.release	= dmirror_fops_release,
+	.mmap		= dmirror_fops_mmap,
 	.unlocked_ioctl = dmirror_fops_unlocked_ioctl,
 	.llseek		= default_llseek,
 	.owner		= THIS_MODULE,