Re: Buffers not reachable by PCI

[Konrad Rzeszutek Wilk <konrad@darnok.org>]

On Thu, Dec 15, 2011 at 02:19:55AM +0000, Taylor, Neal E wrote:
> Missed this when I was composing the previous e-mail. Your answer is here. Thank you.
> 

Can I put 'Tested-by: Neal ..' on this patch:

> >From 47409eecc08effe20fc4aa0da899dd6ac475cb0b Mon Sep 17 00:00:00 2001
> From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> Date: Wed, 14 Dec 2011 20:48:01 -0500
> Subject: [PATCH] xen/swiotlb: Use page alignment for early buffer allocation.
> 
> This piggybacks on git commit e79f86b2ef9c0a8c47225217c1018b7d3d90101c
> "swiotlb: Use page alignment for early buffer allocation" which:
> 
> "We could call free_bootmem_late() if swiotlb is not used, and
> it will shrink to page alignment.
> 
> So alloc them with page alignment at first, to avoid lose two pages"
> 
> Reported-by: "Kalev, Leonid" <Leonid.Kalev@ca.com>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> ---
>  drivers/xen/swiotlb-xen.c |    5 +++--
>  1 files changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
> index 8e964b9..5c8e445 100644
> --- a/drivers/xen/swiotlb-xen.c
> +++ b/drivers/xen/swiotlb-xen.c
> @@ -166,7 +166,8 @@ retry:
>  	/*
>  	 * Get IO TLB memory from any location.
>  	 */
> -	xen_io_tlb_start = alloc_bootmem(bytes);
> +	xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
> +
>  	if (!xen_io_tlb_start) {
>  		m = "Cannot allocate Xen-SWIOTLB buffer!\n";
>  		goto error;
> @@ -179,7 +180,7 @@ retry:
>  			       bytes,
>  			       xen_io_tlb_nslabs);
>  	if (rc) {
> -		free_bootmem(__pa(xen_io_tlb_start), bytes);
> +		free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
>  		m = "Failed to get contiguous memory for DMA from Xen!\n"\
>  		    "You either: don't have the permissions, do not have"\
>  		    " enough free memory under 4GB, or the hypervisor memory"\
> -- 
> 1.7.1