On Thu, 20 Mar 2025, Michał Winiarski wrote:
> There are multiple places where conversions between IOV resources and
> corresponding VF BAR numbers are done.
>
> Extract the logic to pci_resource_num_from_vf_bar() and
> pci_resource_num_to_vf_bar() helpers.
>
> Suggested-by: Ilpo Järvinen <ilpo.jarvi...@linux.intel.com>
> Signed-off-by: Michał Winiarski <michal.winiar...@intel.com>
> Acked-by: Christian König <christian.koe...@amd.com>
> ---
> drivers/pci/iov.c | 22 ++++++++++++----------
> drivers/pci/pci.h | 19 +++++++++++++++++++
> drivers/pci/setup-bus.c | 3 ++-
> 3 files changed, 33 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c
> index bf95387993cd5..985ea11339c45 100644
> --- a/drivers/pci/iov.c
> +++ b/drivers/pci/iov.c
> @@ -151,7 +151,7 @@ resource_size_t pci_iov_resource_size(struct pci_dev
> *dev, int resno)
> if (!dev->is_physfn)
> return 0;
>
> - return dev->sriov->barsz[resno - PCI_IOV_RESOURCES];
> + return dev->sriov->barsz[pci_resource_num_to_vf_bar(resno)];
> }
>
> static void pci_read_vf_config_common(struct pci_dev *virtfn)
> @@ -322,12 +322,13 @@ int pci_iov_add_virtfn(struct pci_dev *dev, int id)
> virtfn->multifunction = 0;
>
> for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
> - res = &dev->resource[i + PCI_IOV_RESOURCES];
> + res = &dev->resource[pci_resource_num_from_vf_bar(i)];
> if (!res->parent)
> continue;
> virtfn->resource[i].name = pci_name(virtfn);
> virtfn->resource[i].flags = res->flags;
> - size = pci_iov_resource_size(dev, i + PCI_IOV_RESOURCES);
> + size = pci_iov_resource_size(dev,
> + pci_resource_num_from_vf_bar(i));
> resource_set_range(&virtfn->resource[i],
> res->start + size * id, size);
> rc = request_resource(res, &virtfn->resource[i]);
> @@ -624,8 +625,8 @@ static int sriov_enable(struct pci_dev *dev, int
> nr_virtfn)
>
> nres = 0;
> for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
> - bars |= (1 << (i + PCI_IOV_RESOURCES));
> - res = &dev->resource[i + PCI_IOV_RESOURCES];
> + bars |= (1 << pci_resource_num_from_vf_bar(i));
> + res = &dev->resource[pci_resource_num_from_vf_bar(i)];
> if (res->parent)
> nres++;
> }
> @@ -791,8 +792,9 @@ static int sriov_init(struct pci_dev *dev, int pos)
>
> nres = 0;
> for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
> - res = &dev->resource[i + PCI_IOV_RESOURCES];
> - res_name = pci_resource_name(dev, i + PCI_IOV_RESOURCES);
> + res = &dev->resource[pci_resource_num_from_vf_bar(i)];
> + res_name = pci_resource_name(dev,
> + pci_resource_num_from_vf_bar(i));
All these get easier to read if you add (same comment for the cases
above):
int idx = pci_resource_num_from_vf_bar(i);
>
> /*
> * If it is already FIXED, don't change it, something
> @@ -851,7 +853,7 @@ static int sriov_init(struct pci_dev *dev, int pos)
> dev->is_physfn = 0;
> failed:
> for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
> - res = &dev->resource[i + PCI_IOV_RESOURCES];
> + res = &dev->resource[pci_resource_num_from_vf_bar(i)];
> res->flags = 0;
> }
>
> @@ -913,7 +915,7 @@ static void sriov_restore_state(struct pci_dev *dev)
> pci_write_config_word(dev, iov->pos + PCI_SRIOV_CTRL, ctrl);
>
> for (i = 0; i < PCI_SRIOV_NUM_BARS; i++)
> - pci_update_resource(dev, i + PCI_IOV_RESOURCES);
> + pci_update_resource(dev, pci_resource_num_from_vf_bar(i));
>
> pci_write_config_dword(dev, iov->pos + PCI_SRIOV_SYS_PGSIZE, iov->pgsz);
> pci_iov_set_numvfs(dev, iov->num_VFs);
> @@ -979,7 +981,7 @@ void pci_iov_update_resource(struct pci_dev *dev, int
> resno)
> {
> struct pci_sriov *iov = dev->is_physfn ? dev->sriov : NULL;
> struct resource *res = pci_resource_n(dev, resno);
> - int vf_bar = resno - PCI_IOV_RESOURCES;
> + int vf_bar = pci_resource_num_to_vf_bar(resno);
> struct pci_bus_region region;
> u16 cmd;
> u32 new;
> diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
> index adc54bb2c8b34..f44840ee3c327 100644
> --- a/drivers/pci/pci.h
> +++ b/drivers/pci/pci.h
> @@ -693,6 +693,15 @@ static inline bool pci_resource_is_iov(int resno)
> {
> return resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END;
> }
> +static inline int pci_resource_num_from_vf_bar(int resno)
> +{
> + return resno + PCI_IOV_RESOURCES;
> +}
> +
> +static inline int pci_resource_num_to_vf_bar(int resno)
> +{
> + return resno - PCI_IOV_RESOURCES;
> +}
> extern const struct attribute_group sriov_pf_dev_attr_group;
> extern const struct attribute_group sriov_vf_dev_attr_group;
> #else
> @@ -717,6 +726,16 @@ static inline bool pci_resource_is_iov(int resno)
> {
> return false;
> }
> +static inline int pci_resource_num_from_vf_bar(int resno)
> +{
> + WARN_ON_ONCE(1);
> + return -ENODEV;
> +}
> +static inline int pci_resource_num_to_vf_bar(int resno)
> +{
> + WARN_ON_ONCE(1);
> + return -ENODEV;
> +}
> #endif /* CONFIG_PCI_IOV */
>
> #ifdef CONFIG_PCIE_TPH
> diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c
> index 54d6f4fa3ce16..55e91ba1e74a2 100644
> --- a/drivers/pci/setup-bus.c
> +++ b/drivers/pci/setup-bus.c
> @@ -1885,7 +1885,8 @@ static int iov_resources_unassigned(struct pci_dev
> *dev, void *data)
> bool *unassigned = data;
>
> for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
> - struct resource *r = &dev->resource[i + PCI_IOV_RESOURCES];
> + struct resource *r =
> + &dev->resource[pci_resource_num_from_vf_bar(i)];
I'd add int idx here as well.
> struct pci_bus_region region;
>
> /* Not assigned or rejected by kernel? */
>
--
i.
