Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751510AbcLEM1h (ORCPT ); Mon, 5 Dec 2016 07:27:37 -0500 Received: from foss.arm.com ([217.140.101.70]:44602 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750855AbcLEM1e (ORCPT ); Mon, 5 Dec 2016 07:27:34 -0500 From: Lorenzo Pieralisi To: Joerg Roedel , "Rafael J. Wysocki" , iommu@lists.linux-foundation.org Cc: Lorenzo Pieralisi , Will Deacon , Hanjun Guo , Bjorn Helgaas , Robin Murphy , Tomasz Nowicki , Sricharan R , Sinan Kaya , Nate Watterson , Prem Mallappa , Dennis Chen , linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH] ACPI/IORT: Make dma masks set-up IORT specific Date: Mon, 5 Dec 2016 12:26:19 +0000 Message-Id: <20161205122619.25045-1-lorenzo.pieralisi@arm.com> X-Mailer: git-send-email 2.10.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4515 Lines: 126 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 --- 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. 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