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Subject: Re: [PATCH] Handle init_iova_flush_queue failure in dma-iommu path
To:     Joerg Roedel <joro@8bytes.org>, Tom Murphy <murphyt7@tcd.ie>
Cc:     iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org
References: <20200910122539.3662-1-murphyt7@tcd.ie>
 <20200918085501.GJ31590@8bytes.org>
From:   Robin Murphy <robin.murphy@arm.com>
Message-ID: <82d5f9c9-1001-3ed3-05f2-1a3b87ca023d@arm.com>
Date:   Fri, 18 Sep 2020 14:51:32 +0100
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On 2020-09-18 09:55, Joerg Roedel wrote:
> On Thu, Sep 10, 2020 at 01:25:38PM +0100, Tom Murphy wrote:
>> init_iova_flush_queue can fail if we run out of memory. Fall back to noflush
>>   queue if it fails.
>>
>> Signed-off-by: Tom Murphy <murphyt7@tcd.ie>
>> ---
>>   drivers/iommu/dma-iommu.c | 7 +++++--
>>   1 file changed, 5 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>> index 4959f5df21bd..5f69126f3e91 100644
>> --- a/drivers/iommu/dma-iommu.c
>> +++ b/drivers/iommu/dma-iommu.c
>> @@ -343,8 +343,11 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base,
>>   
>>   	if (!cookie->fq_domain && !iommu_domain_get_attr(domain,
>>   			DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE, &attr) && attr) {
>> -		cookie->fq_domain = domain;
>> -		init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all, NULL);
>> +		if (init_iova_flush_queue(iovad, iommu_dma_flush_iotlb_all,
>> +					NULL))
>> +			pr_warn("iova flush queue initialization failed\n");
>> +		else
>> +			cookie->fq_domain = domain;
>>   	}
>>   
>>   	if (!dev)
> 
> Looks good to me, but Robin should also have a look.

Yup, seems reasonable, thanks Tom!

Reviewed-by: Robin Murphy <robin.murphy@arm.com>