[RFC 3/4] vduse: Add the function for get/free the mapp pages

[Cindy Lu <lulu@redhat.com>]

From: Your Name <you@example.com>

Add the function for get/free pages, ad this info
will saved in dev->reconnect_info

Signed-off-by: Cindy Lu <lulu@redhat.com>
---
 drivers/vdpa/vdpa_user/vduse_dev.c | 35 ++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c b/drivers/vdpa/vdpa_user/vduse_dev.c
index 1b833bf0ae37..3df1256eccb4 100644
--- a/drivers/vdpa/vdpa_user/vduse_dev.c
+++ b/drivers/vdpa/vdpa_user/vduse_dev.c
@@ -1313,6 +1313,35 @@ static struct vduse_dev *vduse_dev_get_from_minor(int minor)
 	return dev;
 }
 
+int vduse_get_vq_reconnnect(struct vduse_dev *dev, u16 idx)
+{
+	struct vdpa_reconnect_info *area;
+	void *addr = (void *)get_zeroed_page(GFP_KERNEL);
+
+	area = &dev->reconnect_info[idx];
+
+	area->addr = virt_to_phys(addr);
+	area->vaddr = (unsigned long)addr;
+	area->size = PAGE_SIZE;
+	area->index = idx;
+
+	return 0;
+}
+
+int vduse_free_vq_reconnnect(struct vduse_dev *dev, u16 idx)
+{
+	struct vdpa_reconnect_info *area;
+
+	area = &dev->reconnect_info[idx];
+	if ((area->size == PAGE_SIZE) && (area->addr != NULL)) {
+		free_page(area->vaddr);
+		area->size = 0;
+		area->addr = 0;
+		area->vaddr = 0;
+	}
+
+	return 0;
+}
 
 static vm_fault_t vduse_vm_fault(struct vm_fault *vmf)
 {
@@ -1446,6 +1475,10 @@ static int vduse_destroy_dev(char *name)
 		mutex_unlock(&dev->lock);
 		return -EBUSY;
 	}
+	for (int i = 0; i < dev->vq_num; i++) {
+
+		vduse_free_vq_reconnnect(dev, i);
+	}
 	dev->connected = true;
 	mutex_unlock(&dev->lock);
 
@@ -1583,6 +1616,8 @@ static int vduse_create_dev(struct vduse_dev_config *config,
 		INIT_WORK(&dev->vqs[i].kick, vduse_vq_kick_work);
 		spin_lock_init(&dev->vqs[i].kick_lock);
 		spin_lock_init(&dev->vqs[i].irq_lock);
+
+		vduse_get_vq_reconnnect(dev, i);
 	}
 
 	ret = idr_alloc(&vduse_idr, dev, 1, VDUSE_DEV_MAX, GFP_KERNEL);
-- 
2.34.3