linux-kernel - Re: [PATCH 6/6] PCI MSI: Add support for multiple MSI

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:	Mon, 16 Mar 2009 15:07:26 -0600
From:	Matthew Wilcox <matthew@....cx>
To:	Michael Ellerman <michael@...erman.id.au>
Cc:	linux-pci@...r.kernel.org, jbarnes@...tuousgeek.org,
	linux-kernel@...r.kernel.org,
	Matthew Wilcox <willy@...ux.intel.com>
Subject: Re: [PATCH 6/6] PCI MSI: Add support for multiple MSI

On Tue, Mar 03, 2009 at 11:16:13AM +1100, Michael Ellerman wrote:
> > diff --git a/arch/powerpc/kernel/msi.c b/arch/powerpc/kernel/msi.c
> > index 3bb7d3d..0c16e2a 100644
> > --- a/arch/powerpc/kernel/msi.c
> > +++ b/arch/powerpc/kernel/msi.c
> > @@ -19,6 +19,10 @@ int arch_msi_check_device(struct pci_dev* dev, int nvec, int type)
> >  		return -ENOSYS;
> >  	}
> >  
> > +	/* PowerPC doesn't support multiple MSI yet */
> > +	if (type == PCI_CAP_ID_MSI && nvec > 1)
> > +		return 1;
> > +
> >  	if (ppc_md.msi_check_device) {
> >  		pr_debug("msi: Using platform check routine.\n");
> >  		return ppc_md.msi_check_device(dev, nvec, type);
> 
> That bit:
> 
> Acked-by: Michael Ellerman <michael@...erman.id.au>
> 
> I'll tell benh to expect this hunk to show up sometime via Jesse's tree.

Thanks!

> Looks good otherwise, not sure if we'll ever implement it, but good to
> have. Is AHCI the only driver you're planning on using it for ATM?

That's the only one I know where it's important.  I think some PCIe
bridges would like to have multiple MSI.  And I think some hardware
designs (not from Intel, from other companies who've talked to me) are
in the pipe to use multiple MSI, because it's cheaper than using MSI-X.

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/