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Date:   Mon, 8 Jun 2020 00:04:11 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Stefano Stabellini <sstabellini@kernel.org>
Cc:     jgross@suse.com, boris.ostrovsky@oracle.com,
        konrad.wilk@oracle.com, xen-devel@lists.xenproject.org,
        linux-kernel@vger.kernel.org, tamas@tklengyel.com,
        roman@zededa.com,
        Stefano Stabellini <stefano.stabellini@xilinx.com>
Subject: Re: [PATCH v2 01/11] swiotlb-xen: use vmalloc_to_page on vmalloc
 virt addresses
Message-ID: <20200608070411.GA15742@infradead.org>
References: <alpine.DEB.2.21.2006031506590.6774@sstabellini-ThinkPad-T480s>
 <20200603222247.11681-1-sstabellini@kernel.org>
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Well, this isn't just RPi4, but basically any ARM or ARM64 system
with non-coherent DMA (which is most of them).

> +	struct page *pg;

Please spell out page.

>  
>  	if (hwdev && hwdev->coherent_dma_mask)
>  		dma_mask = hwdev->coherent_dma_mask;
> @@ -346,9 +347,11 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
>  	/* Convert the size to actually allocated. */
>  	size = 1UL << (order + XEN_PAGE_SHIFT);
>  
> +	pg = is_vmalloc_addr(vaddr) ? vmalloc_to_page(vaddr) :
> +				      virt_to_page(vaddr);

Please use plain old if/else to make this more readable.