Re: [PATCH] igb_uio: fix Xen compatibility with kernel 3.18

[Jincheng Miao <jmiao-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

ACK, kernel-3.18.0 drops _PAGE_IOMAP.

On 12/12/2014 03:33 AM, Shu Shen wrote:
> This patch fixes build failing with undefined symbol _PAGE_IOMAP with
> kernel 3.18.
>
> The Xen-specific _PAGE_IOMAP PTE flag was removed in kernel 3.18 and
> could be used for other purpose in future. This patch ensures that
> _PAGE_IOMAP flag is only used for kernels before 3.18.
>
> Signed-off-by: Shu Shen <shu.shen-4y/IbmOpLWVBDgjK7y7TUQ@public.gmane.org>
> ---
>   lib/librte_eal/linuxapp/igb_uio/compat.h  | 4 ++++
>   lib/librte_eal/linuxapp/igb_uio/igb_uio.c | 2 ++
>   2 files changed, 6 insertions(+)
>
> diff --git a/lib/librte_eal/linuxapp/igb_uio/compat.h b/lib/librte_eal/linuxapp/igb_uio/compat.h
> index 9454382..c1d45a6 100644
> --- a/lib/librte_eal/linuxapp/igb_uio/compat.h
> +++ b/lib/librte_eal/linuxapp/igb_uio/compat.h
> @@ -11,6 +11,10 @@
>   #define pci_cfg_access_unlock pci_unblock_user_cfg_access
>   #endif
>   
> +#if LINUX_VERSION_CODE < KERNEL_VERSION(3, 18, 0)
> +#define HAVE_PTE_MASK_PAGE_IOMAP
> +#endif
> +
>   #ifndef PCI_MSIX_ENTRY_SIZE
>   #define PCI_MSIX_ENTRY_SIZE             16
>   #define  PCI_MSIX_ENTRY_LOWER_ADDR      0
> diff --git a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> index 47ff2f3..60a2db1 100644
> --- a/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> +++ b/lib/librte_eal/linuxapp/igb_uio/igb_uio.c
> @@ -287,7 +287,9 @@ igbuio_dom0_mmap_phys(struct uio_info *info, struct vm_area_struct *vma)
>   
>   	idx = (int)vma->vm_pgoff;
>   	vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
> +#if defined(HAVE_PTE_MASK_PAGE_IOMAP)
>   	vma->vm_page_prot.pgprot |= _PAGE_IOMAP;
> +#endif
>   
>   	return remap_pfn_range(vma,
>   			vma->vm_start,