[PATCH] NTB: epf: Avoid pci_iounmap() with offset when PEER_SPAD and CONFIG share BAR

When BAR_PEER_SPAD and BAR_CONFIG share one PCI BAR, the module teardown
path ends up calling pci_iounmap() on the same iomem with some offset,
which is unnecessary and triggers a kernel warning like the following:

  Trying to vunmap() nonexistent vm area (0000000069a5ffe8)
  WARNING: mm/vmalloc.c:3470 at vunmap+0x58/0x68, CPU#5: modprobe/2937
  [...]
  Call trace:
   vunmap+0x58/0x68 (P)
   iounmap+0x34/0x48
   pci_iounmap+0x2c/0x40
   ntb_epf_pci_remove+0x44/0x80 [ntb_hw_epf]
   pci_device_remove+0x48/0xf8
   device_remove+0x50/0x88
   device_release_driver_internal+0x1c8/0x228
   driver_detach+0x50/0xb0
   bus_remove_driver+0x74/0x100
   driver_unregister+0x34/0x68
   pci_unregister_driver+0x34/0xa0
   ntb_epf_pci_driver_exit+0x14/0xfe0 [ntb_hw_epf]
  [...]

Fix it by unmapping only when PEER_SPAD and CONFIG use difference bars.

Cc: [email protected]
Fixes: e75d5ae8ab88 ("NTB: epf: Allow more flexibility in the memory BAR map method")
Reviewed-by: Frank Li <[email protected]>
Signed-off-by: Koichiro Den <[email protected]>
---
Split off from a previously combined series:
https://lore.kernel.org/linux-pci/[email protected]/

 drivers/ntb/hw/epf/ntb_hw_epf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/ntb/hw/epf/ntb_hw_epf.c b/drivers/ntb/hw/epf/ntb_hw_epf.c
index d3ecf25a5162..9935da48a52e 100644
--- a/drivers/ntb/hw/epf/ntb_hw_epf.c
+++ b/drivers/ntb/hw/epf/ntb_hw_epf.c
@@ -646,7 +646,8 @@ static void ntb_epf_deinit_pci(struct ntb_epf_dev *ndev)
 	struct pci_dev *pdev = ndev->ntb.pdev;
 
 	pci_iounmap(pdev, ndev->ctrl_reg);
-	pci_iounmap(pdev, ndev->peer_spad_reg);
+	if (ndev->barno_map[BAR_PEER_SPAD] != ndev->barno_map[BAR_CONFIG])
+		pci_iounmap(pdev, ndev->peer_spad_reg);
 	pci_iounmap(pdev, ndev->db_reg);
 
 	pci_release_regions(pdev);
-- 
2.51.0