From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Vrabel <david.vrabel@citrix.com>
Subject: Re: [PATCH] xen: Add __GFP_DMA flag when
 xen_swiotlb_init gets free pages.
Date: Mon, 20 Apr 2015 11:53:47 +0100
Message-ID: <5534DABB.5060305@citrix.com>
References: <1429526904-27176-1-git-send-email-cbz@baozis.org>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <xen-devel-bounces@lists.xen.org>
In-Reply-To: <1429526904-27176-1-git-send-email-cbz@baozis.org>
List-Unsubscribe: <http://lists.xen.org/cgi-bin/mailman/options/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=unsubscribe>
List-Post: <mailto:xen-devel@lists.xen.org>
List-Help: <mailto:xen-devel-request@lists.xen.org?subject=help>
List-Subscribe: <http://lists.xen.org/cgi-bin/mailman/listinfo/xen-devel>,
	<mailto:xen-devel-request@lists.xen.org?subject=subscribe>
Sender: xen-devel-bounces@lists.xen.org
Errors-To: xen-devel-bounces@lists.xen.org
To: Chen Baozi <cbz@baozis.org>, xen-devel@lists.xen.org
Cc: stefano.stabellini@eu.citrix.com
List-Id: xen-devel@lists.xenproject.org

On 20/04/15 11:48, Chen Baozi wrote:
> Make sure that xen_swiotlb_init allocates buffers that is DMA capable.
> 
> Signed-off-by: Chen Baozi <baozich@gmail.com>
> ---
>  drivers/xen/swiotlb-xen.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
> index 810ad41..7345afd 100644
> --- a/drivers/xen/swiotlb-xen.c
> +++ b/drivers/xen/swiotlb-xen.c
> @@ -235,7 +235,8 @@ retry:
>  #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
>  #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
>  		while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
> -			xen_io_tlb_start = (void *)__get_free_pages(__GFP_NOWARN, order);
> +			xen_io_tlb_start = (void *)__get_free_pages(
> +						__GFP_NOWARN|__GFP_DMA, order);

I think this breaks x86 where __GFP_DMA means below 16 MB.  Perhaps you
mean __GFP_DMA32?

David