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Subject: Re: [PATCH 08/10] swiotlb-xen: introduce phys_to_dma/dma_to_phys
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To:     Stefano Stabellini <sstabellini@kernel.org>
Cc:     jgross@suse.com, konrad.wilk@oracle.com,
        xen-devel@lists.xenproject.org, linux-kernel@vger.kernel.org,
        Stefano Stabellini <stefano.stabellini@xilinx.com>
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From:   Boris Ostrovsky <boris.ostrovsky@oracle.com>
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Message-ID: <bf29c0a5-9933-a20e-d37e-4ed44ac7df84@oracle.com>
Date:   Fri, 22 May 2020 14:29:02 -0400
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On 5/22/20 1:34 PM, Stefano Stabellini wrote:
> On Thu, 21 May 2020, Boris Ostrovsky wrote:
>> On 5/20/20 7:45 PM, Stefano Stabellini wrote:
>>> From: Stefano Stabellini <stefano.stabellini@xilinx.com>
>>>
>>> Call dma_to_phys in is_xen_swiotlb_buffer.
>>> Call phys_to_dma in xen_phys_to_bus.
>>> Call dma_to_phys in xen_bus_to_phys.
>>>
>>> Everything is taken care of by these changes except for
>>> xen_swiotlb_alloc_coherent and xen_swiotlb_free_coherent, which need a
>>> few explicit phys_to_dma/dma_to_phys calls.
>>>
>>> Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
>>> ---
>>>  drivers/xen/swiotlb-xen.c | 20 ++++++++++++--------
>>>  1 file changed, 12 insertions(+), 8 deletions(-)
>>>
>>> diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
>>> index c50448fd9b75..d011c4c7aa72 100644
>>> --- a/drivers/xen/swiotlb-xen.c
>>> +++ b/drivers/xen/swiotlb-xen.c
>>> @@ -64,14 +64,16 @@ static inline dma_addr_t xen_phys_to_bus(struct device *dev, phys_addr_t paddr)
>>>  
>>>  	dma |= paddr & ~XEN_PAGE_MASK;
>>>  
>>> -	return dma;
>>> +	return phys_to_dma(dev, dma);
>>>  }
>>>  
>>> -static inline phys_addr_t xen_bus_to_phys(struct device *dev, dma_addr_t baddr)
>>> +static inline phys_addr_t xen_bus_to_phys(struct device *dev,
>>> +					  dma_addr_t dma_addr)
>>
>> Since now dma address != bus address this is no longer
>> xen_bus_to_phys(). (And I guess the same is rue for xen_phys_to_bus()).
> Should I rename them to xen_dma_to_phys and xen_phys_to_dma?


Yes, please.


-boris