[PATCH v3 5/7] vfio: move barmap to a separate function and export

[<ankita@nvidia.com>]

From: Ankit Agrawal <ankita@nvidia.com>

Move the code to map the BAR to a separate function.

This would be reused by the nvgrace-gpu module.

Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
---
 drivers/vfio/pci/vfio_pci_core.c | 38 ++++++++++++++++++++++----------
 include/linux/vfio_pci_core.h    |  1 +
 2 files changed, 27 insertions(+), 12 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 29dcf78905a6..d1ff1c0aa727 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -1717,6 +1717,29 @@ static const struct vm_operations_struct vfio_pci_mmap_ops = {
 #endif
 };
 
+int vfio_pci_core_barmap(struct vfio_pci_core_device *vdev, unsigned int index)
+{
+	struct pci_dev *pdev = vdev->pdev;
+	int ret;
+
+	if (vdev->barmap[index])
+		return 0;
+
+	ret = pci_request_selected_regions(pdev,
+					   1 << index, "vfio-pci");
+	if (ret)
+		return ret;
+
+	vdev->barmap[index] = pci_iomap(pdev, index, 0);
+	if (!vdev->barmap[index]) {
+		pci_release_selected_regions(pdev, 1 << index);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_pci_core_barmap);
+
 int vfio_pci_core_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
 {
 	struct vfio_pci_core_device *vdev =
@@ -1761,18 +1784,9 @@ int vfio_pci_core_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma
 	 * Even though we don't make use of the barmap for the mmap,
 	 * we need to request the region and the barmap tracks that.
 	 */
-	if (!vdev->barmap[index]) {
-		ret = pci_request_selected_regions(pdev,
-						   1 << index, "vfio-pci");
-		if (ret)
-			return ret;
-
-		vdev->barmap[index] = pci_iomap(pdev, index, 0);
-		if (!vdev->barmap[index]) {
-			pci_release_selected_regions(pdev, 1 << index);
-			return -ENOMEM;
-		}
-	}
+	ret = vfio_pci_core_barmap(vdev, index);
+	if (ret)
+		return ret;
 
 	vma->vm_private_data = vdev;
 	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index a097a66485b4..75f04d613e0c 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -121,6 +121,7 @@ ssize_t vfio_pci_core_write(struct vfio_device *core_vdev, const char __user *bu
 		size_t count, loff_t *ppos);
 vm_fault_t vfio_pci_map_pfn(struct vm_fault *vmf, unsigned long pfn,
 			    unsigned int order);
+int vfio_pci_core_barmap(struct vfio_pci_core_device *vdev, unsigned int index);
 int vfio_pci_core_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma);
 void vfio_pci_core_request(struct vfio_device *core_vdev, unsigned int count);
 int vfio_pci_core_match(struct vfio_device *core_vdev, char *buf);
-- 
2.34.1