From mboxrd@z Thu Jan  1 00:00:00 1970
From: Rusty Russell <rusty@rustcorp.com.au>
Subject: Re: [RFC 7/11] virtio_pci: new, capability-aware driver.
Date: Mon, 12 Dec 2011 09:15:03 +1030
Message-ID: <87boreohhs.fsf@rustcorp.com.au>
References: <87pqfzgy6p.fsf@rustcorp.com.au> <87zkf3fiu2.fsf@rustcorp.com.au>
	<20111211094256.GB11504@redhat.com>
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To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Sasha Levin <levinsasha928@gmail.com>, virtualization <virtualization@lists.linux-foundation.org>
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On Sun, 11 Dec 2011 11:42:56 +0200, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> On Thu, Dec 08, 2011 at 09:09:33PM +1030, Rusty Russell wrote:
> > +/* There is no iowrite64.  We use two 32-bit ops. */
> > +static void iowrite64(u64 val, const __le64 *addr)
> > +{
> > +	iowrite32((u32)val, (__le32 *)addr);
> > +	iowrite32(val >> 32, (__le32 *)addr + 1);
> > +}
> > +
> 
> Let's put addr_lo/addr_hi in the structure then,
> to make the fact this field is not atomic explicit?

Good point, assuming I haven't missed something.

Are 64-bit accesses actually unknown in PCI-land?  Or is this a limited
availability thing?

Thanks,
Rusty.