[PATCH 1/3] PCI/IOV: Remember initial VF BAR sizes

[Marcin Bernatowicz]

SR-IOV initialization records the per-VF BAR sizes derived from the VF
BAR registers in the SR-IOV capability.

PF drivers may later change VF BAR sizes using VF Resizable BAR support
(pci_iov_vf_bar_set_size()). Save the initial per-VF BAR sizes so later
code can restore them when SR-IOV is disabled, when SR-IOV enable fails,
or when the PF driver is unbound while VF BARs are still resized.

The initial size is captured before the resource is multiplied by
TotalVFs, so it represents one VF's BAR size as advertised by hardware.

No functional change on its own.

Signed-off-by: Marcin Bernatowicz <marcin.bernatowicz@xxxxxxxxxxxxxxx>
---
 drivers/pci/iov.c | 1 +
 drivers/pci/pci.h | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
index 30ca4535fc36..19f4dca4eec1 100644
--- a/drivers/pci/iov.c
+++ b/drivers/pci/iov.c
@@ -869,6 +869,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
 			goto failed;
 		}
 		iov->barsz[i] = resource_size(res);
+		iov->barsz_orig[i] = iov->barsz[i];
 		resource_set_size(res, resource_size(res) * total);
 		pci_info(dev, "%s %pR: contains BAR %d for %d VFs\n",
 			 res_name, res, i, total);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 19660d068fb7..441ef5b4ddc2 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -670,7 +670,8 @@ struct pci_sriov {
 	u8		hdr_type;	/* VF header type */
 	u16		subsystem_vendor; /* VF subsystem vendor */
 	u16		subsystem_device; /* VF subsystem device */
-	resource_size_t	barsz[PCI_SRIOV_NUM_BARS];	/* VF BAR size */
+	resource_size_t	barsz[PCI_SRIOV_NUM_BARS];	/* Current VF BAR size */
+	resource_size_t	barsz_orig[PCI_SRIOV_NUM_BARS]; /* Initial VF BAR size at probe */
 	u16		vf_rebar_cap;	/* VF Resizable BAR capability offset */
 	bool		drivers_autoprobe; /* Auto probing of VFs by driver */
 };
-- 
2.43.0