[PATCH V4 vfio 7/9] vfio/pci: Expose vfio_pci_core_setup_barmap()

[Yishai Hadas <yishaih@xxxxxxxxxx>]

Expose vfio_pci_core_setup_barmap() to be used by drivers.

This will let drivers to mmap a BAR and re-use it from both vfio and the
driver when it's applicable.

This API will be used in the next patches by the vfio/virtio coming
driver.

Signed-off-by: Yishai Hadas <yishaih@xxxxxxxxxx>
---
 drivers/vfio/pci/vfio_pci_core.c | 25 +++++++++++++++++++++++++
 drivers/vfio/pci/vfio_pci_rdwr.c | 28 ++--------------------------
 include/linux/vfio_pci_core.h    |  1 +
 3 files changed, 28 insertions(+), 26 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci_core.c b/drivers/vfio/pci/vfio_pci_core.c
index 1929103ee59a..ebea39836dd9 100644
--- a/drivers/vfio/pci/vfio_pci_core.c
+++ b/drivers/vfio/pci/vfio_pci_core.c
@@ -684,6 +684,31 @@ void vfio_pci_core_disable(struct vfio_pci_core_device *vdev)
 }
 EXPORT_SYMBOL_GPL(vfio_pci_core_disable);
 
+int vfio_pci_core_setup_barmap(struct vfio_pci_core_device *vdev, int bar)
+{
+	struct pci_dev *pdev = vdev->pdev;
+	void __iomem *io;
+	int ret;
+
+	if (vdev->barmap[bar])
+		return 0;
+
+	ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
+	if (ret)
+		return ret;
+
+	io = pci_iomap(pdev, bar, 0);
+	if (!io) {
+		pci_release_selected_regions(pdev, 1 << bar);
+		return -ENOMEM;
+	}
+
+	vdev->barmap[bar] = io;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(vfio_pci_core_setup_barmap);
+
 void vfio_pci_core_close_device(struct vfio_device *core_vdev)
 {
 	struct vfio_pci_core_device *vdev =
diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c
index e27de61ac9fe..6f08b3ecbb89 100644
--- a/drivers/vfio/pci/vfio_pci_rdwr.c
+++ b/drivers/vfio/pci/vfio_pci_rdwr.c
@@ -200,30 +200,6 @@ static ssize_t do_io_rw(struct vfio_pci_core_device *vdev, bool test_mem,
 	return done;
 }
 
-static int vfio_pci_setup_barmap(struct vfio_pci_core_device *vdev, int bar)
-{
-	struct pci_dev *pdev = vdev->pdev;
-	int ret;
-	void __iomem *io;
-
-	if (vdev->barmap[bar])
-		return 0;
-
-	ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
-	if (ret)
-		return ret;
-
-	io = pci_iomap(pdev, bar, 0);
-	if (!io) {
-		pci_release_selected_regions(pdev, 1 << bar);
-		return -ENOMEM;
-	}
-
-	vdev->barmap[bar] = io;
-
-	return 0;
-}
-
 ssize_t vfio_pci_bar_rw(struct vfio_pci_core_device *vdev, char __user *buf,
 			size_t count, loff_t *ppos, bool iswrite)
 {
@@ -262,7 +238,7 @@ ssize_t vfio_pci_bar_rw(struct vfio_pci_core_device *vdev, char __user *buf,
 		}
 		x_end = end;
 	} else {
-		int ret = vfio_pci_setup_barmap(vdev, bar);
+		int ret = vfio_pci_core_setup_barmap(vdev, bar);
 		if (ret) {
 			done = ret;
 			goto out;
@@ -438,7 +414,7 @@ int vfio_pci_ioeventfd(struct vfio_pci_core_device *vdev, loff_t offset,
 		return -EINVAL;
 #endif
 
-	ret = vfio_pci_setup_barmap(vdev, bar);
+	ret = vfio_pci_core_setup_barmap(vdev, bar);
 	if (ret)
 		return ret;
 
diff --git a/include/linux/vfio_pci_core.h b/include/linux/vfio_pci_core.h
index 562e8754869d..67ac58e20e1d 100644
--- a/include/linux/vfio_pci_core.h
+++ b/include/linux/vfio_pci_core.h
@@ -127,6 +127,7 @@ int vfio_pci_core_match(struct vfio_device *core_vdev, char *buf);
 int vfio_pci_core_enable(struct vfio_pci_core_device *vdev);
 void vfio_pci_core_disable(struct vfio_pci_core_device *vdev);
 void vfio_pci_core_finish_enable(struct vfio_pci_core_device *vdev);
+int vfio_pci_core_setup_barmap(struct vfio_pci_core_device *vdev, int bar);
 pci_ers_result_t vfio_pci_core_aer_err_detected(struct pci_dev *pdev,
 						pci_channel_state_t state);
 
-- 
2.27.0