Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751936AbcLFJgM (ORCPT ); Tue, 6 Dec 2016 04:36:12 -0500 Received: from foss.arm.com ([217.140.101.70]:33672 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751690AbcLFJfz (ORCPT ); Tue, 6 Dec 2016 04:35:55 -0500 Date: Tue, 6 Dec 2016 09:37:10 +0000 From: Lorenzo Pieralisi To: Joerg Roedel Cc: "Rafael J. Wysocki" , "open list:AMD IOMMU (AMD-VI)" , Will Deacon , Hanjun Guo , Bjorn Helgaas , Robin Murphy , Tomasz Nowicki , Sricharan R , Sinan Kaya , Nate Watterson , Prem Mallappa , Dennis Chen , ACPI Devel Maling List , Linux PCI , Linux Kernel Mailing List , "linux-arm-kernel@lists.infradead.org" Subject: Re: [PATCH] ACPI/IORT: Make dma masks set-up IORT specific Message-ID: <20161206093710.GA4432@red-moon> References: <20161205122619.25045-1-lorenzo.pieralisi@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5914 Lines: 147 Hi Joerg, On Mon, Dec 05, 2016 at 11:18:56PM +0100, Rafael J. Wysocki wrote: > On Mon, Dec 5, 2016 at 1:26 PM, Lorenzo Pieralisi > wrote: > > The introduction of acpi_dma_configure() allows to configure DMA > > and related IOMMU for any device that is DMA capable. To achieve > > that goal it ensures DMA masks are set-up to sane default values > > before proceeding with IOMMU and DMA ops configuration. > > > > On x86/ia64 systems, through acpi_bind_one(), acpi_dma_configure() is > > called for every device that has an ACPI companion, in that every device > > is considered DMA capable on x86/ia64 systems (ie acpi_get_dma_attr() API), > > which has the side effect of initializing dma masks also for > > pseudo-devices (eg CPUs and memory nodes) and potentially for devices > > whose dma masks were not set-up before the acpi_dma_configure() API was > > introduced, which may have noxious side effects. > > > > Therefore, in preparation for IORT firmware specific DMA masks set-up, > > wrap the default DMA masks set-up in acpi_dma_configure() inside an IORT > > specific wrapper that reverts to a NOP on x86/ia64 systems, restoring the > > default expected behaviour on x86/ia64 systems and keeping DMA default > > masks set-up on IORT based (ie ARM) arch configurations. > > > > Signed-off-by: Lorenzo Pieralisi > > Cc: Will Deacon > > Cc: Hanjun Guo > > Cc: Bjorn Helgaas > > Cc: Robin Murphy > > Cc: Tomasz Nowicki > > Cc: Joerg Roedel > > Cc: "Rafael J. Wysocki" > > Cc: Sricharan R > > Acked -by: Rafael J. Wysocki > > > --- > > Joerg, > > > > pending Rafael's ACK on it, given the 4.10 release timing and that the > > series is queued via the IOMMU tree please consider applying this patch to > > your arm/smmu branch for 4.10, it is not fixing a bug but it is modifying > > the x86/ia64 code path; I prefer preventing any issue related to default > > dma masks on x86/ia64 so I hope it can get merged along with the rest of > > the ACPI IORT SMMU series. I can apply Rafael and Hanjun's tags and resend a v2 to you if you prefer, it would be great if you could apply this patch to your arm/smmu branch for v4.10 as per description above, please let me know. Thank you ! Lorenzo > > > > Thanks a lot and apologies, > > Lorenzo > > > > drivers/acpi/arm64/iort.c | 22 ++++++++++++++++++++++ > > drivers/acpi/scan.c | 14 +------------- > > include/linux/acpi_iort.h | 2 ++ > > 3 files changed, 25 insertions(+), 13 deletions(-) > > > > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c > > index 47bace8..e0d2e6e 100644 > > --- a/drivers/acpi/arm64/iort.c > > +++ b/drivers/acpi/arm64/iort.c > > @@ -547,6 +547,28 @@ static const struct iommu_ops *iort_iommu_xlate(struct device *dev, > > } > > > > /** > > + * iort_set_dma_mask - Set-up dma mask for a device. > > + * > > + * @dev: device to configure > > + */ > > +void iort_set_dma_mask(struct device *dev) > > +{ > > + /* > > + * Set default coherent_dma_mask to 32 bit. Drivers are expected to > > + * setup the correct supported mask. > > + */ > > + if (!dev->coherent_dma_mask) > > + dev->coherent_dma_mask = DMA_BIT_MASK(32); > > + > > + /* > > + * Set it to coherent_dma_mask by default if the architecture > > + * code has not set it. > > + */ > > + if (!dev->dma_mask) > > + dev->dma_mask = &dev->coherent_dma_mask; > > +} > > + > > +/** > > * iort_iommu_configure - Set-up IOMMU configuration for a device. > > * > > * @dev: device to configure > > diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c > > index 80698d3..93b00cf 100644 > > --- a/drivers/acpi/scan.c > > +++ b/drivers/acpi/scan.c > > @@ -1380,19 +1380,7 @@ void acpi_dma_configure(struct device *dev, enum dev_dma_attr attr) > > { > > const struct iommu_ops *iommu; > > > > - /* > > - * Set default coherent_dma_mask to 32 bit. Drivers are expected to > > - * setup the correct supported mask. > > - */ > > - if (!dev->coherent_dma_mask) > > - dev->coherent_dma_mask = DMA_BIT_MASK(32); > > - > > - /* > > - * Set it to coherent_dma_mask by default if the architecture > > - * code has not set it. > > - */ > > - if (!dev->dma_mask) > > - dev->dma_mask = &dev->coherent_dma_mask; > > + iort_set_dma_mask(dev); > > > > iommu = iort_iommu_configure(dev); > > > > diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h > > index dcb2b60..77e0809 100644 > > --- a/include/linux/acpi_iort.h > > +++ b/include/linux/acpi_iort.h > > @@ -35,6 +35,7 @@ bool iort_node_match(u8 type); > > u32 iort_msi_map_rid(struct device *dev, u32 req_id); > > struct irq_domain *iort_get_device_domain(struct device *dev, u32 req_id); > > /* IOMMU interface */ > > +void iort_set_dma_mask(struct device *dev); > > const struct iommu_ops *iort_iommu_configure(struct device *dev); > > #else > > static inline void acpi_iort_init(void) { } > > @@ -45,6 +46,7 @@ static inline struct irq_domain *iort_get_device_domain(struct device *dev, > > u32 req_id) > > { return NULL; } > > /* IOMMU interface */ > > +static inline void iort_set_dma_mask(struct device *dev) { } > > static inline > > const struct iommu_ops *iort_iommu_configure(struct device *dev) > > { return NULL; } > > -- > > 2.10.0 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html