From: Robin Murphy <robin.murphy@arm.com>
To: Bjorn Helgaas <helgaas@kernel.org>,
Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>,
Tomasz Nowicki <tn@semihalf.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
linux-kernel@vger.kernel.org, Will Deacon <will.deacon@arm.com>,
linux-pci@vger.kernel.org, Sinan Kaya <okaya@codeaurora.org>,
linux-acpi@vger.kernel.org, iommu@lists.linux-foundation.org,
Hanjun Guo <hanjun.guo@linaro.org>, Jon Masters <jcm@redhat.com>,
Bjorn Helgaas <bhelgaas@google.com>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC PATCH 09/11] drivers: acpi: implement acpi_dma_configure
Date: Fri, 15 Apr 2016 17:31:58 +0100 [thread overview]
Message-ID: <5711177E.2000509@arm.com> (raw)
In-Reply-To: <20160415161400.GC7973@localhost>
Hi Bjorn,
On 15/04/16 17:14, Bjorn Helgaas wrote:
> On Thu, Apr 14, 2016 at 06:25:41PM +0100, Lorenzo Pieralisi wrote:
>> On DT based systems, the of_dma_configure() API implements DMA configuration
>> for a given device. On ACPI systems an API equivalent to of_dma_configure()
>> is missing which implies that it is currently not possible to set-up DMA
>> operations for devices through the ACPI generic kernel layer.
>>
>> This patch fills the gap by introducing acpi_dma_configure/deconfigure()
>> calls, that carry out IOMMU configuration through IORT (on systems where
>> it is present) and call arch_setup_dma_ops(...) with the retrieved
>> parameters.
>>
>> The DMA range size passed to arch_setup_dma_ops() is sized according
>> to the device coherent_dma_mask (starting at address 0x0), mirroring the
>> DT probing path behaviour when a dma-ranges property is not provided
>> for the device being probed; this changes the current arch_setup_dma_ops()
>> call parameters in the ACPI probing case, but since arch_setup_dma_ops()
>> is a NOP on all architectures but ARM/ARM64 this patch does not change
>> the current kernel behaviour on them.
>>
>> This patch updates ACPI and PCI core code to use the newly introduced
>> acpi_dma_configure function, providing the same functionality
>> as of_dma_configure on ARM systems and leaving behaviour unchanged
>> for all other arches.
>>
>> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
>> Cc: Bjorn Helgaas <bhelgaas@google.com>
>> Cc: Robin Murphy <robin.murphy@arm.com>
>> Cc: Tomasz Nowicki <tn@semihalf.com>
>> Cc: Joerg Roedel <joro@8bytes.org>
>> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
>
> There's only a tiny PCI change in this series, so I assume somebody
> else will merge all this. Here's my ack for the PCI part:
>
> Acked-by: Bjorn Helgaas <bhelgaas@google.com> # for drivers/pci/probe.c change
>
> One question on use of pci_for_each_dma_alias() below.
>
>> +static int __get_pci_rid(struct pci_dev *pdev, u16 alias, void *data)
>> +{
>> + u32 *rid = data;
>> +
>> + *rid = alias;
>> + return 0;
>> +}
>> +
>> +/**
>> + * iort_iommu_configure - Set-up IOMMU configuration for a device.
>> + *
>> + * @dev: device that requires IOMMU set-up
>> + *
>> + * Returns: iommu_ops pointer on configuration success
>> + * NULL on configuration failure
>> + */
>> +struct iommu_ops *iort_iommu_configure(struct device *dev)
>> +{
>> + struct acpi_iort_node *node, *parent;
>> + struct iommu_ops *ops = NULL;
>> + struct iommu_fwspec fwspec;
>> + struct iort_iommu_node *iommu_node;
>> + u32 rid = 0, devid = 0;
>> +
>> + if (dev_is_pci(dev)) {
>> + struct pci_bus *bus = to_pci_dev(dev)->bus;
>> +
>> + pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid,
>> + &rid);
>
> You end up with only the last DMA alias in "rid". Is it really true
> that you only need to call iort_dev_map_rid() for one of the aliases?
Indeed - all we care about is what things look like by the time they
come out of the root complex on their way to the the IOMMU, so whatever
intermediate aliasing _within_ the PCI bus might happen along the way
doesn't actually matter.
Robin.
>> + node = iort_scan_node(ACPI_IORT_NODE_PCI_ROOT_COMPLEX,
>> + iort_find_dev_callback, &bus->dev);
>> + } else
>> + node = iort_scan_node(ACPI_IORT_NODE_NAMED_COMPONENT,
>> + iort_find_dev_callback, dev);
>> +
>> + if (!node)
>> + return NULL;
>> +
>> + iort_dev_map_rid(node, rid, &devid, ACPI_IORT_NODE_SMMU);
>> +
>> + parent = iort_find_parent_node(node, ACPI_IORT_NODE_SMMU);
>> +
>> + if (!parent)
>> + return NULL;
>> +
>> + iommu_node = iort_iommu_get_node(parent);
>> + ops = iommu_node->ops;
>> +
>> + fwspec.fwnode = iommu_node->fwnode;
>> + fwspec.param_count = 1;
>> + fwspec.param[0] = devid;
>> +
>> + if (!ops || !ops->fw_xlate || ops->fw_xlate(dev, &fwspec))
>> + return NULL;
>> +
>> + return ops;
>> +}
> _______________________________________________
> iommu mailing list
> iommu@lists.linux-foundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/iommu
>
next prev parent reply other threads:[~2016-04-15 16:32 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-04-14 17:25 [RFC PATCH 00/11] ACPI IORT ARM SMMU support Lorenzo Pieralisi
2016-04-14 17:25 ` [RFC PATCH 01/11] drivers: acpi: iort: fix struct pci_dev compiler warnings Lorenzo Pieralisi
2016-04-14 17:25 ` [RFC PATCH 02/11] drivers: acpi: iort: add support for IOMMU registration Lorenzo Pieralisi
2016-04-14 17:25 ` [RFC PATCH 03/11] drivers: iommu: add FWNODE_IOMMU fwnode type Lorenzo Pieralisi
2016-04-14 17:25 ` [RFC PATCH 04/11] drivers: acpi: iort: introduce linker section for IORT entries probing Lorenzo Pieralisi
2016-04-14 17:25 ` [RFC PATCH 05/11] drivers: iommu: arm-smmu: split probe functions into DT/generic portions Lorenzo Pieralisi
2016-04-14 17:25 ` [RFC PATCH 06/11] drivers: iommu: make of_xlate() interface DT agnostic Lorenzo Pieralisi
2016-04-19 8:28 ` Marek Szyprowski
2016-04-19 11:30 ` Lorenzo Pieralisi
2016-04-20 7:14 ` Marek Szyprowski
2016-04-14 17:25 ` [RFC PATCH 07/11] drivers: iommu: arm-smmu: allow ACPI based streamid translation Lorenzo Pieralisi
2016-04-14 17:25 ` [RFC PATCH 08/11] drivers: acpi: iort: enhance mapping API Lorenzo Pieralisi
2016-04-14 17:25 ` [RFC PATCH 09/11] drivers: acpi: implement acpi_dma_configure Lorenzo Pieralisi
2016-04-15 16:14 ` Bjorn Helgaas
2016-04-15 16:31 ` Robin Murphy [this message]
2016-04-15 18:29 ` Timur Tabi
2016-04-18 10:30 ` Lorenzo Pieralisi
2016-04-18 10:43 ` Robin Murphy
2016-05-16 15:15 ` Tomasz Nowicki
2016-05-16 15:26 ` Tomasz Nowicki
2016-04-21 22:45 ` Andy Shevchenko
2016-04-22 10:57 ` Lorenzo Pieralisi
2016-05-17 8:07 ` Tomasz Nowicki
2016-05-17 12:32 ` Tomasz Nowicki
2016-04-14 17:25 ` [RFC PATCH 10/11] drivers: iommu: arm-smmu: implement ACPI probing Lorenzo Pieralisi
2016-04-14 17:25 ` [RFC PATCH 11/11] drivers: irqchip: make struct irq_fwspec generic Lorenzo Pieralisi
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