PCI/IDE: Fix off by one error calculating VF RID range

The VF ID range of an SR-IOV device is [0, num_VFs - 1].
pci_ide_stream_alloc() mistakenly uses num_VFs to represent the last ID.
Fix that off by one error to stay in bounds of the range.

Fixes: 1e4d2ff ("PCI/IDE: Add IDE establishment helpers")
Signed-off-by: Li Ming <[email protected]>
Reviewed-by: Xu Yilun <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Dan Williams <[email protected]>

Author: liming011

drivers/pci/ide.c

@@ -282,8 +282,8 @@ struct pci_ide *pci_ide_stream_alloc(struct pci_dev *pdev)
 	/* for SR-IOV case, cover all VFs */
 	num_vf = pci_num_vf(pdev);
 	if (num_vf)
-		rid_end = PCI_DEVID(pci_iov_virtfn_bus(pdev, num_vf),
-				    pci_iov_virtfn_devfn(pdev, num_vf));
+		rid_end = PCI_DEVID(pci_iov_virtfn_bus(pdev, num_vf - 1),
+				    pci_iov_virtfn_devfn(pdev, num_vf - 1));
 	else
 		rid_end = pci_dev_id(pdev);
 

include/linux/pci-ide.h

@@ -26,7 +26,7 @@ enum pci_ide_partner_select {
 /**
  * struct pci_ide_partner - Per port pair Selective IDE Stream settings
  * @rid_start: Partner Port Requester ID range start
- * @rid_end: Partner Port Requester ID range end
+ * @rid_end: Partner Port Requester ID range end (inclusive)
  * @stream_index: Selective IDE Stream Register Block selection
  * @mem_assoc: PCI bus memory address association for targeting peer partner
  * @pref_assoc: PCI bus prefetchable memory address association for