From mboxrd@z Thu Jan  1 00:00:00 1970
From: Olav Haugan <ohaugan-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>
Subject: Re: [PATCH v5 1/1] iommu-api: Add map_sg/unmap_sg functions
Date: Tue, 12 Aug 2014 09:53:44 -0700
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To: Konrad Rzeszutek Wilk <konrad.wilk-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
Cc: kgene.kim-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org, linux-arm-msm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, laurent.pinchart+renesas-ryLnwIuWjnjg/C1BVhZhaw@public.gmane.org, will.deacon-5wv7dgnIgG8@public.gmane.org, iommu-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, Varun.Sethi-KZfg59tc24xl57MIdRCFDg@public.gmane.org, dwmw2-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org
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On 8/11/2014 6:35 PM, Konrad Rzeszutek Wilk wrote:
> On Mon, Aug 11, 2014 at 03:45:50PM -0700, Olav Haugan wrote:
> .. snip..
>> +	for_each_sg(sg, s, nents, i) {
>> +		phys_addr_t phys = page_to_phys(sg_page(s));
>> +		size_t page_len = s->offset + s->length;
>> +
>> +		ret = iommu_map(domain, iova + offset, phys, page_len,
>> +				prot);
>> +		if (ret) {
>> +			/* undo mappings already done */
>> +			iommu_unmap(domain, iova, offset);
> 
> Don't we want then to unmap all of the scatter list instead of just
> the last one?
> 

It reverts all the mapping that was already done up until the error
occurred. "offset" contains the amount we have mapped so far.

Thanks,

Olav

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