From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: linuxppc-dev@ozlabs.org, Dave Airlie <airlied@linux.ie>,
linux-pci@vger.kernel.org, Anton Blanchard <anton@au1.ibm.com>,
Brian King <brking@linux.vnet.ibm.com>,
Yijing Wang <wangyijing@huawei.com>, Takashi Iwai <tiwai@suse.de>,
Alex Deucher <alexdeucher@gmail.com>
Subject: Re: [PATCH 1/4] pci/msi: Move "force_32bit_msi" flag from powerpc to generic pci_dev
Date: Thu, 02 Oct 2014 08:09:50 +1000 [thread overview]
Message-ID: <1412201390.4285.233.camel@pasglop> (raw)
In-Reply-To: <20141001203322.GE4171@google.com>
On Wed, 2014-10-01 at 14:33 -0600, Bjorn Helgaas wrote:
> I like the idea of handling this more generically, e.g., with a bit like
> this in struct pci_dev (I'd probably name it something like "no_64bit_msi"
> along the lines of your driver #defines).
>
> What I don't like is that we haven't done anything to help other
> architectures, because the only code that *looks* at this bit is in
> arch/powerpc. The next arch that tries to use 64-bit MSI addresses for
> these devices will trip over the same problem.
I started looking. From my (limited) understanding of x86, it doesn't
even look at the "size" of MSIs which makes me think it's always 32-bit,
and I plan to look at the others next (though not for stable).
> Can we check in pci_enable_msi_range() and pci_enable_msix_range() whether
> the MSI addresses allocated by the arch are too big, and fail the call if
> they are?
Yes, good idea, I'll add something.
Cheers,
Ben.
next prev parent reply other threads:[~2014-10-01 22:10 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1412048401.4285.128.camel@pasglop>
[not found] ` <CAErSpo4B6kuZJcKwreNvW1qC5sZ=1Ko71vbzNz7T8-_pjf7mww@mail.gmail.com>
[not found] ` <CADnq5_PT+dX=KA4epGNRaoraco2z1pe5K7UgqLmTUhWMnvtWkw@mail.gmail.com>
[not found] ` <1412108504.4285.155.camel@pasglop>
[not found] ` <CADnq5_O_iLAZUKLL4nph8VwuP2NOkWXhBZC2XTSkFm5P42WZ+g@mail.gmail.com>
[not found] ` <1412110946.4285.158.camel@pasglop>
[not found] ` <CADnq5_OXBax1+TKPsR2RDYTWijQKDVw34ECfWzcwN2SibCGYTg@mail.gmail.com>
[not found] ` <1412112324.4285.160.camel@pasglop>
2014-10-01 2:09 ` [PATCH 1/4] pci/msi: Move "force_32bit_msi" flag from powerpc to generic pci_dev Benjamin Herrenschmidt
2014-10-01 20:33 ` Bjorn Helgaas
2014-10-01 22:09 ` Benjamin Herrenschmidt [this message]
2014-10-02 0:33 ` [PATCH v2 1/4] pci/msi: Move "no_64bit_msi" " Benjamin Herrenschmidt
2014-10-02 1:48 ` Stephen Rothwell
2014-10-02 0:34 ` Benjamin Herrenschmidt
2014-10-02 15:31 ` Bjorn Helgaas
2014-10-02 21:01 ` Benjamin Herrenschmidt
2014-10-02 21:46 ` Bjorn Helgaas
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