On Mon, 12 Aug 2019 15:02:34 -0500
Bjorn Helgaas <helgaas@xxxxxxxxxx> wrote:
> On Sun, Aug 11, 2019 at 06:08:04PM +0300, Denis Efremov wrote:
> > This patch refactors the loop condition scheme from
> > 'i <= PCI_STD_RESOURCE_END' to 'i < PCI_STD_NUM_BARS'.
> >
> > Signed-off-by: Denis Efremov <efremov@xxxxxxxxx>
> > ---
> > drivers/vfio/pci/vfio_pci.c | 4 ++--
> > drivers/vfio/pci/vfio_pci_config.c | 2 +-
> > drivers/vfio/pci/vfio_pci_private.h | 4 ++--
> > 3 files changed, 5 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/vfio/pci/vfio_pci.c b/drivers/vfio/pci/vfio_pci.c
> > index 703948c9fbe1..13f5430e3f3c 100644
> > --- a/drivers/vfio/pci/vfio_pci.c
> > +++ b/drivers/vfio/pci/vfio_pci.c
> > @@ -115,7 +115,7 @@ static void vfio_pci_probe_mmaps(struct vfio_pci_device *vdev)
> >
> > INIT_LIST_HEAD(&vdev->dummy_resources_list);
> >
> > - for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) {
> > + for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
> > res = vdev->pdev->resource + bar;
>
> PCI_STD_RESOURCES is indeed 0, but since the original went to the
> trouble of avoiding that assumption, I would probably do this:
>
> for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
> res = vdev->pdev->resource + bar + PCI_STD_RESOURCES;
>
> or maybe even this:
>
> res = &vdev->pdev->resource[bar + PCI_STD_RESOURCES];
>
> which is more common outside vfio. But I wouldn't change to using the
> &dev->resource[] form if other vfio code that you're *not* changing
> uses the dev->resource + bar form.
I don't think we have any other instances like that, so the latter form
is fine with me if it's more broadly used. I do spot one use of [bar]
in drivers/vfio/pci/vfio_pci_rdwr.c that could also take on this form
to void the same assumption though. Thanks,
Alex
> > if (!IS_ENABLED(CONFIG_VFIO_PCI_MMAP))
> > @@ -399,7 +399,7 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev)
> >
> > vfio_config_free(vdev);
> >
> > - for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) {
> > + for (bar = 0; bar < PCI_STD_NUM_BARS; bar++) {
> > if (!vdev->barmap[bar])
> > continue;
> > pci_iounmap(pdev, vdev->barmap[bar]);
> > diff --git a/drivers/vfio/pci/vfio_pci_config.c b/drivers/vfio/pci/vfio_pci_config.c
> > index f0891bd8444c..6035a2961160 100644
> > --- a/drivers/vfio/pci/vfio_pci_config.c
> > +++ b/drivers/vfio/pci/vfio_pci_config.c
> > @@ -455,7 +455,7 @@ static void vfio_bar_fixup(struct vfio_pci_device *vdev)
> >
> > bar = (__le32 *)&vdev->vconfig[PCI_BASE_ADDRESS_0];
> >
> > - for (i = PCI_STD_RESOURCES; i <= PCI_STD_RESOURCE_END; i++, bar++) {
> > + for (i = 0; i < PCI_STD_NUM_BARS; i++, bar++) {
> > if (!pci_resource_start(pdev, i)) {
> > *bar = 0; /* Unmapped by host = unimplemented to user */
> > continue;
> > diff --git a/drivers/vfio/pci/vfio_pci_private.h b/drivers/vfio/pci/vfio_pci_private.h
> > index ee6ee91718a4..8a2c7607d513 100644
> > --- a/drivers/vfio/pci/vfio_pci_private.h
> > +++ b/drivers/vfio/pci/vfio_pci_private.h
> > @@ -86,8 +86,8 @@ struct vfio_pci_reflck {
> >
> > struct vfio_pci_device {
> > struct pci_dev *pdev;
> > - void __iomem *barmap[PCI_STD_RESOURCE_END + 1];
> > - bool bar_mmap_supported[PCI_STD_RESOURCE_END + 1];
> > + void __iomem *barmap[PCI_STD_NUM_BARS];
> > + bool bar_mmap_supported[PCI_STD_NUM_BARS];
> > u8 *pci_config_map;
> > u8 *vconfig;
> > struct perm_bits *msi_perm;
> > --
> > 2.21.0
> >
