[PATCH 1/3] vfio/pci: Pull BAR mapping setup from read-write path

From: Alex Williamson
Date: Wed Feb 28 2018 - 15:14:59 EST


This creates a common helper that we'll use for ioeventfd setup.

Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
---
drivers/vfio/pci/vfio_pci_rdwr.c | 39 ++++++++++++++++++++++++++------------
1 file changed, 27 insertions(+), 12 deletions(-)

diff --git a/drivers/vfio/pci/vfio_pci_rdwr.c b/drivers/vfio/pci/vfio_pci_rdwr.c
index 357243d76f10..5f2b376dcebd 100644
--- a/drivers/vfio/pci/vfio_pci_rdwr.c
+++ b/drivers/vfio/pci/vfio_pci_rdwr.c
@@ -113,6 +113,30 @@ static ssize_t do_io_rw(void __iomem *io, char __user *buf,
return done;
}

+static int vfio_pci_setup_barmap(struct vfio_pci_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_device *vdev, char __user *buf,
size_t count, loff_t *ppos, bool iswrite)
{
@@ -147,22 +171,13 @@ ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf,
if (!io)
return -ENOMEM;
x_end = end;
- } else if (!vdev->barmap[bar]) {
- int ret;
-
- ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
+ } else {
+ int ret = vfio_pci_setup_barmap(vdev, bar);
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;
- } else
io = vdev->barmap[bar];
+ }

if (bar == vdev->msix_bar) {
x_start = vdev->msix_offset;