From: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
To: Alexey Kardashevskiy <aik@ozlabs.ru>
Cc: Michael Ellerman <mpe@ellerman.id.au>,
Matthew Wilcox <willy@linux.intel.com>,
Keith Busch <keith.busch@intel.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
David Gibson <david@gibson.dropbear.id.au>,
Christoph Hellwig <hch@infradead.org>,
"David S. Miller" <davem@davemloft.net>,
linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org,
linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org
Subject: Re: [PATCH 4/7 v2] pseries/iommu: implement DDW-aware dma_get_page_shift
Date: Tue, 27 Oct 2015 15:22:29 -0700 [thread overview]
Message-ID: <20151027222229.GE7716@linux.vnet.ibm.com> (raw)
In-Reply-To: <562F11FA.9090805@ozlabs.ru>
On 27.10.2015 [16:56:10 +1100], Alexey Kardashevskiy wrote:
> On 10/24/2015 07:59 AM, Nishanth Aravamudan wrote:
> >When DDW (Dynamic DMA Windows) are present for a device, we have stored
> >the TCE (Translation Control Entry) size in a special device tree
> >property. Check if we have enabled DDW for the device and return the TCE
> >size from that property if present. If the property isn't present,
> >fallback to looking the value up in struct iommu_table. If we don't find
> >a iommu_table, fallback to the kernel's page size.
> >
> >Signed-off-by: Nishanth Aravamudan <nacc@linux.vnet.ibm.com>
> >---
> > arch/powerpc/platforms/pseries/iommu.c | 36 ++++++++++++++++++++++++++++++++++
> > 1 file changed, 36 insertions(+)
> >
> >diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
> >index 0946b98..1bf6471 100644
> >--- a/arch/powerpc/platforms/pseries/iommu.c
> >+++ b/arch/powerpc/platforms/pseries/iommu.c
> >@@ -1292,6 +1292,40 @@ static u64 dma_get_required_mask_pSeriesLP(struct device *dev)
> > return dma_iommu_ops.get_required_mask(dev);
> > }
> >
> >+static unsigned long dma_get_page_shift_pSeriesLP(struct device *dev)
> >+{
> >+ struct iommu_table *tbl;
> >+
> >+ if (!disable_ddw && dev_is_pci(dev)) {
> >+ struct pci_dev *pdev = to_pci_dev(dev);
> >+ struct device_node *dn;
> >+
> >+ dn = pci_device_to_OF_node(pdev);
> >+
> >+ /* search upwards for ibm,dma-window */
> >+ for (; dn && PCI_DN(dn) && !PCI_DN(dn)->table_group;
> >+ dn = dn->parent)
> >+ if (of_get_property(dn, "ibm,dma-window", NULL))
> >+ break;
> >+ /*
> >+ * if there is a DDW configuration, the TCE shift is stored in
> >+ * the property
> >+ */
> >+ if (dn && PCI_DN(dn)) {
> >+ const struct dynamic_dma_window_prop *direct64 =
> >+ of_get_property(dn, DIRECT64_PROPNAME, NULL);
>
>
> This DIRECT64_PROPNAME property is only present under pHyp, QEMU/KVM
> does not set it as 64bit windows are dynamic there so something like
> find_existing_ddw() needs to be used here.
DIRECT64_PROPNAME is a Linux thing, not a pHyp or QEMU/KVM thing -- it's
created by the Linux DDW logic and left in the device-tree when we
successfully configure DDW.
You're right, though, that logically find_existing_ddw() would be better
to use here. I'll spin up a new version.
-Nish
next prev parent reply other threads:[~2015-10-27 22:22 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-10-23 20:54 [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA Nishanth Aravamudan
2015-10-23 20:56 ` [PATCH 1/7 v3] dma-mapping: add generic dma_get_page_shift API Nishanth Aravamudan
2015-10-23 20:57 ` [PATCH 2/7 v2] powerpc/dma-mapping: override dma_get_page_shift Nishanth Aravamudan
2015-10-27 6:02 ` Alexey Kardashevskiy
2015-10-27 14:06 ` Busch, Keith
2015-10-27 22:27 ` Nishanth Aravamudan
2015-10-28 1:00 ` Alexey Kardashevskiy
2015-10-28 1:54 ` Nishanth Aravamudan
2015-10-28 2:20 ` Benjamin Herrenschmidt
2015-10-28 2:30 ` Nishanth Aravamudan
2015-10-28 3:20 ` Benjamin Herrenschmidt
2015-10-23 20:57 ` [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA Nishanth Aravamudan
2015-10-23 20:58 ` [PATCH 3/7 v2] powerpc/dma: implement per-platform dma_get_page_shift Nishanth Aravamudan
2015-10-23 20:59 ` [PATCH 4/7 v2] pseries/iommu: implement DDW-aware dma_get_page_shift Nishanth Aravamudan
2015-10-27 5:56 ` Alexey Kardashevskiy
2015-10-27 22:22 ` Nishanth Aravamudan [this message]
2015-10-23 21:00 ` [PATCH 5/7] [RFC PATCH 5/7] sparc: rename kernel/iommu_common.h -> include/asm/iommu_common.h Nishanth Aravamudan
2015-10-23 21:02 ` Nishanth Aravamudan
2015-10-23 21:01 ` [RFC PATCH 6/7] sparc/dma-mapping: override dma_get_page_shift Nishanth Aravamudan
2015-10-23 21:02 ` [PATCH 7/7 v2] drivers/nvme: default to the IOMMU page size Nishanth Aravamudan
2015-10-27 1:27 ` [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA David Miller
2015-10-27 22:20 ` Nishanth Aravamudan
2015-10-27 22:36 ` Busch, Keith
2015-10-28 0:54 ` David Miller
2015-10-28 13:59 ` Busch, Keith
2015-10-29 11:55 ` Christoph Hellwig
2015-10-29 15:57 ` Nishanth Aravamudan
2015-10-29 17:20 ` Busch, Keith
2015-10-30 21:35 ` [PATCH 1/1 v3] drivers/nvme: default to 4k device page size Nishanth Aravamudan
2015-10-30 21:48 ` Keith Busch
2015-10-30 22:13 ` Nishanth Aravamudan
2015-11-03 13:18 ` Christoph Hellwig
2015-11-03 13:46 ` Keith Busch
2015-11-05 17:01 ` [PATCH 1/1 v4] " Nishanth Aravamudan
2015-11-05 19:58 ` Christoph Hellwig
2015-11-05 21:54 ` Nishanth Aravamudan
2015-11-06 16:13 ` Nishanth Aravamudan
2015-11-13 7:37 ` Christoph Hellwig
2015-11-13 15:08 ` Keith Busch
2015-11-18 14:42 ` Christoph Hellwig
2015-10-30 1:49 ` [PATCH 0/5 v3] Fix NVMe driver support on Power with 32-bit DMA David Miller
2015-10-30 21:35 ` Nishanth Aravamudan
2015-10-27 22:57 ` Julian Calaby
2015-10-27 23:40 ` Nishanth Aravamudan
2015-10-27 23:43 ` Julian Calaby
2015-10-28 0:29 ` Benjamin Herrenschmidt
2015-10-28 1:00 ` David Miller
2015-10-28 0:53 ` David Miller
2015-10-28 1:52 ` Nishanth Aravamudan
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