From: Christoph Hellwig <hch@infradead.org>
To: Oliver O'Halloran <oohall@gmail.com>
Cc: Oded Gabbay <oded.gabbay@gmail.com>,
Greg KH <gregkh@linuxfoundation.org>,
linuxppc-dev@ozlabs.org, Christoph Hellwig <hch@infradead.org>,
"Linux-Kernel@Vger. Kernel. Org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 8/8] habanalabs: enable 64-bit DMA mask in POWER9
Date: Tue, 11 Jun 2019 23:53:14 -0700 [thread overview]
Message-ID: <20190612065314.GA28838@infradead.org> (raw)
In-Reply-To: <CAOSf1CE82uVVni638jkJJpQ7XLXX+HdD7xuB7Wv-f8mn=SBMeg@mail.gmail.com>
On Wed, Jun 12, 2019 at 04:35:22PM +1000, Oliver O'Halloran wrote:
> Setting a 48 bit DMA mask doesn't work today because we only allocate
> IOMMU tables to cover the 0..2GB range of PCI bus addresses.
I don't think that is true upstream, and if it is we need to fix bug
in the powerpc code. powerpc should be falling back treating a 48-bit
dma mask like a 32-bit one at least, that is use dynamic iommu mappings
instead of using the direct mapping. And from my reding of
arch/powerpc/kernel/dma-iommu.c that is exactly what it does.
next prev parent reply other threads:[~2019-06-12 6:53 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-11 9:21 [PATCH v2 8/8] habanalabs: enable 64-bit DMA mask in POWER9 Oded Gabbay
2019-06-11 9:58 ` Greg KH
2019-06-11 11:47 ` Oded Gabbay
2019-06-11 15:17 ` Christoph Hellwig
2019-06-11 15:26 ` Greg KH
2019-06-11 17:03 ` Oded Gabbay
2019-06-11 17:22 ` Oded Gabbay
2019-06-11 22:53 ` Benjamin Herrenschmidt
2019-06-12 5:45 ` Oliver O'Halloran
2019-06-12 8:17 ` Benjamin Herrenschmidt
2019-06-12 6:25 ` Oded Gabbay
2019-06-12 8:18 ` Benjamin Herrenschmidt
2019-06-12 6:35 ` Oliver O'Halloran
2019-06-12 6:53 ` Christoph Hellwig [this message]
2019-06-12 11:48 ` Oliver O'Halloran
2019-06-15 12:12 ` Oded Gabbay
2019-06-16 9:55 ` Christoph Hellwig
2019-06-16 11:24 ` Oded Gabbay
2019-06-17 8:19 ` Christoph Hellwig
2019-06-17 8:35 ` Oded Gabbay
2019-06-24 6:53 ` Oded Gabbay
2019-06-24 6:58 ` Christoph Hellwig
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