[dpdk-dev] [PATCH v4 7/8] virtio: add 1.0 support

Xie, Huawei huawei.xie at intel.com
Tue Jan 19 02:51:30 CET 2016


On 1/19/2016 9:34 AM, Yuanhan Liu wrote:
> On Mon, Jan 18, 2016 at 05:07:51PM +0000, Xie, Huawei wrote:
>> .On 1/15/2016 12:34 PM, Yuanhan Liu wrote:
>>> Modern (v1.0) virtio pci device defines several pci capabilities.
>>> Each cap has a configure structure corresponding to it, and the
>>> cap.bar and cap.offset fields tell us where to find it.
>>>
>> [snip]
>>> +
>>> +static inline void
>>> +io_write64_twopart(uint64_t val, uint32_t *lo, uint32_t *hi)
>>> +{
>>> +	io_write32((uint32_t)val, lo);
>>> +	io_write32(val >> 32,     hi);
>> Firstly your second iowrite32 doesn't do the conversion.
> Because it's not necessary. The first one is for retrieving the low 32
> bits.

I don't mean the shift operation, but the conversion from 64bit to 32bit.
Same applied to below.

>
>> The conversion is duplicated.
> What do you mean by "duplicated".
>
> 	--yliu
>



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