Re: [PATCH] Extending kernel option pci=resource_alignment to be able to specify PCI device/vendor IDs

[Bjorn Helgaas <helgaas@kernel.org>]

On Tue, Jun 07, 2016 at 02:24:17PM +0000, Koehrer Mathias (ETAS/ESW5) wrote:
> Some uio based PCI drivers (e.g. uio_cif) do not work if the assigned 
> PCI memory resources are not page aligned.
> By using the kernel option "pci=resource_alignment" it is possible to force
> single PCI boards to use page alignment for their memory resources.
> However, this is fairly cumbersome if multiple of these boards are in use as 
> the specification of the cards has to be done via PCI bus/slot/function number
> which might change e.g. by adding another board.
> This patch extends the kernel option "pci=resource_alignment" to allow to
> specify the relevant boards via PCI device/vendor (and subdevice/subvendor) ids.
> The specification of the devices via device/vendor is indicated by a leading
> string "pci:" as argument to "pci=resource_alignment".
> The format of the specification is
>   pci:<vendor>:<device>[:<subvendor>:<subdevice>]
> 
> Signed-off-by: Mathias Koehrer <mathias.koehrer@etas.com>
> 
> ---
>  Documentation/kernel-parameters.txt |    2 +
>  drivers/pci/pci.c                   |   66 +++++++++++++++++++++++++-----------
>  2 files changed, 49 insertions(+), 19 deletions(-)
> 
> Index: linux-4.7-rc1/Documentation/kernel-parameters.txt
> ===================================================================
> --- linux-4.7-rc1.orig/Documentation/kernel-parameters.txt
> +++ linux-4.7-rc1/Documentation/kernel-parameters.txt
> @@ -2998,6 +2998,8 @@ bytes respectively. Such letter suffixes
>  		resource_alignment=
>  				Format:
>  				[<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...]
> +				[<order of align>@]pci:<vendor>:<device>\
> +						[:<subvendor>:<subdevice>][; ...] 

Can you include a little example here so we know whether to use
"pci:8086:1234" or "pci:0x8086:0x1234"?

Bjorn