Re: [PATCH v2 1/2] igb_uio: compatible with upstream longterm kernel and RHEL6

[Thomas Monjalon <thomas.monjalon-pdR9zngts4EAvxtiuMwx3w@public.gmane.org>]

2014-10-31 15:37, Jincheng Miao:
> Function pci_num_vf() is introduced from upstream linux-2.6.34. So
> this patch make compatible with longterm kernel linux-2.6.32.63.
> 
> For RHEL6's kernel, although it is based on linux-2.6.32, it has
> pci_num_vf() implementation. As the same with commit 11ba0426,
> pci_num_vf() is defined from RHEL6. So we should check the macro
> RHEL_RELEASE_CODE to consider this situation.

Please, could you explain in which case CONFIG_PCI_IOV is defined?
The logic is a bit difficult to understand.

>  #if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 34) && \
> -	!defined(CONFIG_PCI_IOV)
> +       (!(defined(RHEL_RELEASE_CODE) && \
> +          RHEL_RELEASE_CODE >= RHEL_RELEASE_VERSION(6, 0) && \
> +          defined(CONFIG_PCI_IOV)))
>  
>  static int pci_num_vf(struct pci_dev *dev)
>  {