Re: [PATCH] net: add APIs for manipulating skb page fragments.

[David Miller <davem@davemloft.net>]

From: Ian Campbell <Ian.Campbell@eu.citrix.com>
Date: Sun, 21 Aug 2011 09:23:57 +0100

> On Sun, 2011-08-21 at 01:31 +0100, David Miller wrote:
>> From: Ian Campbell <ian.campbell@citrix.com>
>> Date: Fri, 19 Aug 2011 17:25:00 +0100
>> 
>> > The primary aim is to add skb_frag_(ref|unref) in order to remove the use of
>> > bare get/put_page on SKB pages fragments and to isolate users from subsequent
>> > changes to the skb_frag_t data structure.
>> > 
>> > Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
>> 
>> You're going to have to protect all of the things using the interfaces
>> from linux/dma-mapping.h with CONFIG_HAS_DMA otherwise it won't build
>> on platforms like S390.
> 
> s390 is one of the arches which I build tested and I initially saw this
> issue too. I did add CONFIG_HAS_DMA but it turns out that
> linux/dma-mapping.h takes care of this by including
> asm-generic/dma-mapping-broken.h for you so I removed the #ifdef again.
> The header defines the prototypes to allow building but causes a link
> time failure if anything actually uses the interfaces.
> 
> I just tested a s390x defconfig build again and it appears to be fine.

Thanks for explaining this.

Patch applied, thanks!