Re: [Qemu-devel] Re: [RESEND][PATCH] Add 40-bit DMA support to LSI scsi emulation

[Anthony Liguori <anthony@codemonkey.ws>]

Blue Swirl wrote:
> On 11/17/08, Ryan Harper <ryanh@us.ibm.com> wrote:
>   
>>  Looking for some feedback on this patch, MAINTAINERS points to Paul for
>>  scsi stuff, and I saw Blue Swirl commit a scsi patch recently.
>>
>>  This patch fixes Linux machines configured with > 4G of ram and using a
>>  SCSI device.  I'm working on 64-bit DMA support as well which should
>>  hopefully fix 64-bit Windows using SCSI devices as well.
>>     
>
>     addr = s->dnad;
> +    if (lsi_dma_40bit(s))
> +        addr |= ((uint64_t)s->dnad64 << 32UL);
> +    else if (s->sbms)
> +        addr |= ((uint64_t)s->sbms << 32UL);
>
> Maybe the address could be calculated at script parsing phase for
> small performance gain.
>
> I would use ULL instead of UL, because on 32 bit host long is still 32 bits.
>   

But both ULL and UL are wrong for a shift operation.  It always takes an 
integer.

Regards,

Anthony Liguori