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Date: Wed, 31 Jan 2024 17:45:17 +0000
From: Will Deacon <will@kernel.org>
To: linux-kernel@vger.kernel.org
Cc: kernel-team@android.com, iommu@lists.linux.dev,
	Christoph Hellwig <hch@lst.de>,
	Marek Szyprowski <m.szyprowski@samsung.com>,
	Robin Murphy <robin.murphy@arm.com>,
	Petr Tesarik <petr.tesarik1@huawei-partners.com>,
	Dexuan Cui <decui@microsoft.com>
Subject: Re: [PATCH v2 1/3] swiotlb: Fix allocation alignment requirement
 when searching slots
Message-ID: <20240131174516.GA14943@willie-the-truck>
References: <20240131122543.14791-1-will@kernel.org>
 <20240131122543.14791-2-will@kernel.org>
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In-Reply-To: <20240131122543.14791-2-will@kernel.org>
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On Wed, Jan 31, 2024 at 12:25:41PM +0000, Will Deacon wrote:
> @@ -1015,14 +1014,16 @@ static int swiotlb_search_pool_area(struct device *dev, struct io_tlb_pool *pool
>  	index = area->index;
>  
>  	for (slots_checked = 0; slots_checked < pool->area_nslabs; ) {
> -		slot_index = slot_base + index;
> +		phys_addr_t tlb_addr;
>  
> -		if (orig_addr &&
> -		    (slot_addr(tbl_dma_addr, slot_index) &
> -		     iotlb_align_mask) != (orig_addr & iotlb_align_mask)) {
> +		slot_index = slot_base + index;
> +		tlb_addr = slot_addr(tbl_dma_addr, slot_index);
> +
> +		if ((tlb_addr & alloc_align_mask) ||
> +		    (orig_addr && (tlb_addr & iotlb_align_mask) !=
> +				  (orig_addr & iotlb_align_mask))) {
>  			index = wrap_area_index(pool, index + 1);
>  			slots_checked++;
> -			continue;

Bah, I accidentally dropped this 'continue' when addressing the review
comments, so I'll add it back in v3.

Will