From: Robin Murphy <robin.murphy@arm.com> To: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>, iommu@lists.linux-foundation.org, Marek Szyprowski <m.szyprowski@samsung.com> Cc: linux-arm-kernel@lists.infradead.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>, Marc Zyngier <marc.zyngier@arm.com>, Catalin Marinas <catalin.marinas@arm.com>, Joerg Roedel <joro@8bytes.org>, Will Deacon <will.deacon@arm.com>, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, Sinan Kaya <okaya@codeaurora.org>, linux-acpi@vger.kernel.org, Hanjun Guo <hanjun.guo@linaro.org>, Tomasz Nowicki <tn@semihalf.com>, Jon Masters <jcm@redhat.com> Subject: Re: [RFC PATCH v2 03/15] arm64: mm: change IOMMU notifier action to attach DMA ops Date: Fri, 17 Jun 2016 10:27:22 +0100 [thread overview] Message-ID: <5763C27A.9030306@arm.com> (raw) In-Reply-To: <1465306270-27076-4-git-send-email-lorenzo.pieralisi@arm.com> Hi Lorenzo, I think this patch makes sense even independent of the rest of the series, one nit inline notwithstanding. Marek; I'm curious as to whether this could make the workaround in 722ec35f7 obsolete as well, or are all the drivers also bound super-early in the setup you had there? On 07/06/16 14:30, Lorenzo Pieralisi wrote: > Current bus notifier in ARM64 (__iommu_attach_notifier) > attempts to attach dma_ops to a device on BUS_NOTIFY_ADD_DEVICE > action notification. > > This causes issues on ACPI based systems, where PCI devices > can be added before the IOMMUs the devices are attached to > had a chance to be probed, causing failures on attempts to > attach dma_ops in that the domain for the respective IOMMU > may not be set-up yet by the time the bus notifier is run. > > Devices dma_ops do not require to be set-up till the matching > device drivers are probed. This means that instead of running > the notifier attaching dma_ops to devices (__iommu_attach_notifier) > on BUS_NOTIFY_ADD_DEVICE action, it can be run just before the > device driver is bound to the device in question (on action > BUS_NOTIFY_BIND_DRIVER) so that it is certain that its IOMMU > group and domain are set-up accordingly at the time the > notifier is triggered. > > This patch changes the notifier action upon which dma_ops > are attached to devices and defer it to driver binding time, > so that IOMMU devices have a chance to be probed and to register > their bus notifiers before the dma_ops attach sequence for a > device is actually carried out. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Robin Murphy <robin.murphy@arm.com> > --- > arch/arm64/mm/dma-mapping.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index c566ec8..79b0882 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -848,7 +848,7 @@ static int __iommu_attach_notifier(struct notifier_block *nb, > { > struct iommu_dma_notifier_data *master, *tmp; > > - if (action != BUS_NOTIFY_ADD_DEVICE) > + if (action != BUS_NOTIFY_BIND_DRIVER) With this, you can also get rid of the priority setting and big fat explanatory comment in register_iommu_dma_ops_notifier(). Robin. > return 0; > > mutex_lock(&iommu_dma_notifier_lock); >
WARNING: multiple messages have this Message-ID (diff)
From: robin.murphy@arm.com (Robin Murphy) To: linux-arm-kernel@lists.infradead.org Subject: [RFC PATCH v2 03/15] arm64: mm: change IOMMU notifier action to attach DMA ops Date: Fri, 17 Jun 2016 10:27:22 +0100 [thread overview] Message-ID: <5763C27A.9030306@arm.com> (raw) In-Reply-To: <1465306270-27076-4-git-send-email-lorenzo.pieralisi@arm.com> Hi Lorenzo, I think this patch makes sense even independent of the rest of the series, one nit inline notwithstanding. Marek; I'm curious as to whether this could make the workaround in 722ec35f7 obsolete as well, or are all the drivers also bound super-early in the setup you had there? On 07/06/16 14:30, Lorenzo Pieralisi wrote: > Current bus notifier in ARM64 (__iommu_attach_notifier) > attempts to attach dma_ops to a device on BUS_NOTIFY_ADD_DEVICE > action notification. > > This causes issues on ACPI based systems, where PCI devices > can be added before the IOMMUs the devices are attached to > had a chance to be probed, causing failures on attempts to > attach dma_ops in that the domain for the respective IOMMU > may not be set-up yet by the time the bus notifier is run. > > Devices dma_ops do not require to be set-up till the matching > device drivers are probed. This means that instead of running > the notifier attaching dma_ops to devices (__iommu_attach_notifier) > on BUS_NOTIFY_ADD_DEVICE action, it can be run just before the > device driver is bound to the device in question (on action > BUS_NOTIFY_BIND_DRIVER) so that it is certain that its IOMMU > group and domain are set-up accordingly at the time the > notifier is triggered. > > This patch changes the notifier action upon which dma_ops > are attached to devices and defer it to driver binding time, > so that IOMMU devices have a chance to be probed and to register > their bus notifiers before the dma_ops attach sequence for a > device is actually carried out. > > Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Robin Murphy <robin.murphy@arm.com> > --- > arch/arm64/mm/dma-mapping.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c > index c566ec8..79b0882 100644 > --- a/arch/arm64/mm/dma-mapping.c > +++ b/arch/arm64/mm/dma-mapping.c > @@ -848,7 +848,7 @@ static int __iommu_attach_notifier(struct notifier_block *nb, > { > struct iommu_dma_notifier_data *master, *tmp; > > - if (action != BUS_NOTIFY_ADD_DEVICE) > + if (action != BUS_NOTIFY_BIND_DRIVER) With this, you can also get rid of the priority setting and big fat explanatory comment in register_iommu_dma_ops_notifier(). Robin. > return 0; > > mutex_lock(&iommu_dma_notifier_lock); >
next prev parent reply other threads:[~2016-06-17 9:27 UTC|newest] Thread overview: 88+ messages / expand[flat|nested] mbox.gz Atom feed top 2016-06-07 13:30 [RFC PATCH v2 00/15] ACPI IORT ARM SMMU v3 support Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi [not found] ` <1465306270-27076-1-git-send-email-lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org> 2016-06-07 13:30 ` [RFC PATCH v2 01/15] drivers: acpi: iort: fix struct pci_dev compiler warnings Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi 2016-06-07 13:30 ` [RFC PATCH v2 02/15] drivers: irqchip: its: fix its_acpi_probe() prototype Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi 2016-06-07 13:30 ` [RFC PATCH v2 03/15] arm64: mm: change IOMMU notifier action to attach DMA ops Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi 2016-06-17 9:27 ` Robin Murphy [this message] 2016-06-17 9:27 ` Robin Murphy [not found] ` <5763C27A.9030306-5wv7dgnIgG8@public.gmane.org> 2016-06-17 14:15 ` Lorenzo Pieralisi 2016-06-17 14:15 ` Lorenzo Pieralisi 2016-06-17 14:15 ` Lorenzo Pieralisi 2016-06-23 11:32 ` Robin Murphy 2016-06-23 11:32 ` Robin Murphy 2016-06-21 7:53 ` Marek Szyprowski 2016-06-21 7:53 ` Marek Szyprowski 2016-06-21 7:53 ` Marek Szyprowski 2016-06-21 7:53 ` Marek Szyprowski [not found] ` <03c537e7-0acf-edca-d0e0-369490c828df-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org> 2016-06-21 16:06 ` Lorenzo Pieralisi 2016-06-21 16:06 ` Lorenzo Pieralisi 2016-06-21 16:06 ` Lorenzo Pieralisi 2016-06-21 16:06 ` Lorenzo Pieralisi 2016-06-23 6:13 ` Marek Szyprowski 2016-06-23 6:13 ` Marek Szyprowski 2016-06-07 13:30 ` [RFC PATCH v2 04/15] drivers: acpi: iort: add support for IOMMU registration Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi 2016-06-07 13:30 ` Lorenzo Pieralisi 2016-06-07 13:31 ` [RFC PATCH v2 05/15] drivers: acpi: iort: add support for named component look-up Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` [RFC PATCH v2 06/15] drivers: acpi: iort: enhance device identifiers mappings Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` [RFC PATCH v2 08/15] drivers: acpi: iort: add support for ARM SMMU platform devices creation Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` [RFC PATCH v2 09/15] drivers: iommu: arm-smmu-v3: split probe functions into DT/generic portions Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-14 18:09 ` Will Deacon 2016-06-14 18:09 ` Will Deacon 2016-06-07 13:31 ` [RFC PATCH v2 10/15] drivers: iommu: arm-smmu-v3: enable ACPI driver initialization Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-14 18:12 ` Will Deacon 2016-06-14 18:12 ` Will Deacon 2016-06-07 13:31 ` [RFC PATCH v2 13/15] drivers: acpi: iort: introduce iort_iommu_configure Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-10 12:46 ` Tomasz Nowicki 2016-06-10 12:46 ` Tomasz Nowicki 2016-06-10 12:46 ` Tomasz Nowicki 2016-06-07 13:31 ` [RFC PATCH v2 07/15] drivers: acpi: iort: add node match function Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` [RFC PATCH v2 11/15] drivers: iommu: arm-smmu-v3: add IORT iommu configuration Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-14 18:39 ` Will Deacon 2016-06-14 18:39 ` Will Deacon [not found] ` <20160614183939.GL16531-5wv7dgnIgG8@public.gmane.org> 2016-06-15 8:52 ` Lorenzo Pieralisi 2016-06-15 8:52 ` Lorenzo Pieralisi 2016-06-15 8:52 ` Lorenzo Pieralisi 2016-06-07 13:31 ` [RFC PATCH v2 12/15] drivers: acpi: implement acpi_dma_configure Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi [not found] ` <1465306270-27076-13-git-send-email-lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org> 2016-06-10 16:25 ` Bjorn Helgaas 2016-06-10 16:25 ` Bjorn Helgaas 2016-06-10 16:25 ` Bjorn Helgaas 2016-06-07 13:31 ` [RFC PATCH v2 14/15] drivers: acpi: iort: add function to retrieve IOMMU platform devices Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-07 13:31 ` [RFC PATCH v2 15/15] drivers: iommu: arm-smmu-v3: allow ACPI based streamid translation Lorenzo Pieralisi 2016-06-07 13:31 ` Lorenzo Pieralisi 2016-06-21 10:37 ` [RFC PATCH v2 00/15] ACPI IORT ARM SMMU v3 support Hanjun Guo 2016-06-21 10:37 ` Hanjun Guo 2016-06-21 10:37 ` Hanjun Guo [not found] ` <b00f33ad-be24-21a9-b03b-611756bbc8e9-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org> 2016-06-21 14:27 ` Lorenzo Pieralisi 2016-06-21 14:27 ` Lorenzo Pieralisi 2016-06-21 14:27 ` Lorenzo Pieralisi 2016-06-21 14:27 ` Lorenzo Pieralisi 2016-06-22 2:45 ` Hanjun Guo 2016-06-22 2:45 ` Hanjun Guo 2016-06-22 2:45 ` Hanjun Guo
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