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SubjectRe: [PATCH 1/2] PCI: Add support for VF Resizable Bar extended cap
Hi Michał,

[...]
> +static int pci_memory_decoding(struct pci_dev *dev)
> +{
> + u16 cmd;
> +
> + pci_read_config_word(dev, PCI_COMMAND, &cmd);
> + if (cmd & PCI_COMMAND_MEMORY)
> + return -EBUSY;
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_PCI_IOV
> +static int pci_vf_memory_decoding(struct pci_dev *dev)
> +{
> + u16 cmd;
> +
> + pci_read_config_word(dev, dev->sriov->pos + PCI_SRIOV_CTRL, &cmd);
> + if (cmd & PCI_SRIOV_CTRL_MSE)
> + return -EBUSY;
> +
> + return 0;
> +}
> +#endif
> +
> int pci_resize_resource(struct pci_dev *dev, int resno, int size)
> {
> struct resource *res = dev->resource + resno;
> struct pci_host_bridge *host;
> int old, ret;
> u32 sizes;
> - u16 cmd;
>
> /* Check if we must preserve the firmware's resource assignment */
> host = pci_find_host_bridge(dev->bus);
> @@ -424,9 +447,14 @@ int pci_resize_resource(struct pci_dev *dev, int resno, int size)
> if (!(res->flags & IORESOURCE_UNSET))
> return -EBUSY;
>
> - pci_read_config_word(dev, PCI_COMMAND, &cmd);
> - if (cmd & PCI_COMMAND_MEMORY)
> - return -EBUSY;
> +#ifdef CONFIG_PCI_IOV
> + if (resno >= PCI_IOV_RESOURCES)
> + ret = pci_vf_memory_decoding(dev);
> + else
> +#endif
> + ret = pci_memory_decoding(dev);
> + if (ret)
> + return ret;

The above else works, however, it does trip our static analysis tools, and
lack of the indentation makes it slightly confusing to read, at least at
the first glance. Thus, I wonder whether it would be possible to combine
the pci_vf_memory_decoding() and pci_memory_decoding() somehow neatly into
a private helper that takes a boolean to indicate whether it's a VF or not.
Then, we could drop the if-statement, since some of the logic could live
within the helper.

What do you think?

Krzysztof

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