Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752160AbcDUIl4 (ORCPT ); Thu, 21 Apr 2016 04:41:56 -0400 Received: from mail-wm0-f49.google.com ([74.125.82.49]:35751 "EHLO mail-wm0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751526AbcDUIly (ORCPT ); Thu, 21 Apr 2016 04:41:54 -0400 Subject: Re: [PATCH v7 08/10] iommu/dma-reserved_iommu: iommu_msi_mapping_desc_to_domain To: Robin Murphy , eric.auger@st.com, alex.williamson@redhat.com, will.deacon@arm.com, joro@8bytes.org, tglx@linutronix.de, jason@lakedaemon.net, marc.zyngier@arm.com, christoffer.dall@linaro.org, linux-arm-kernel@lists.infradead.org References: <1461084994-2355-1-git-send-email-eric.auger@linaro.org> <1461084994-2355-9-git-send-email-eric.auger@linaro.org> <5717BA3E.8050901@arm.com> Cc: patches@linaro.org, linux-kernel@vger.kernel.org, Bharat.Bhushan@freescale.com, pranav.sawargaonkar@gmail.com, p.fedin@samsung.com, iommu@lists.linux-foundation.org, Jean-Philippe.Brucker@arm.com, julien.grall@arm.com From: Eric Auger Message-ID: <57189206.2000708@linaro.org> Date: Thu, 21 Apr 2016 10:40:38 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <5717BA3E.8050901@arm.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3433 Lines: 115 Hi Robin, On 04/20/2016 07:19 PM, Robin Murphy wrote: > On 19/04/16 17:56, Eric Auger wrote: >> This function checks whether >> - the device emitting the MSI belongs to a non default iommu domain >> - the iommu domain requires the MSI address to be mapped. >> >> If those conditions are met, the function returns the iommu domain >> to be used for mapping the MSI doorbell; else it returns NULL. >> >> Signed-off-by: Eric Auger >> --- >> drivers/iommu/dma-reserved-iommu.c | 19 +++++++++++++++++++ >> include/linux/dma-reserved-iommu.h | 18 ++++++++++++++++++ >> 2 files changed, 37 insertions(+) >> >> diff --git a/drivers/iommu/dma-reserved-iommu.c >> b/drivers/iommu/dma-reserved-iommu.c >> index 2522235..907a17f 100644 >> --- a/drivers/iommu/dma-reserved-iommu.c >> +++ b/drivers/iommu/dma-reserved-iommu.c >> @@ -17,6 +17,7 @@ >> >> #include >> #include >> +#include >> >> struct reserved_iova_domain { >> struct iova_domain *iovad; >> @@ -332,3 +333,21 @@ unlock: >> } >> EXPORT_SYMBOL_GPL(iommu_put_reserved_iova); >> >> +struct iommu_domain *iommu_msi_mapping_desc_to_domain(struct msi_desc >> *desc) >> +{ >> + struct device *dev; >> + struct iommu_domain *d; >> + >> + dev = msi_desc_to_dev(desc); >> + >> + d = iommu_get_domain_for_dev(dev); >> + >> + if (!d || (d->type == IOMMU_DOMAIN_DMA)) >> + return NULL; >> + >> + if (iommu_domain_get_attr(d, DOMAIN_ATTR_MSI_MAPPING, NULL)) >> + return NULL; > > Yeah, I don't see why we couldn't just use > > if (domain->ops->capable(IOMMU_CAP_INTR_REMAP)) > return NULL I don't think this works. This will lead to MSI iommu mapping on x86 when irq_remapping is disabled. To be further checked though. Eric > > there instead. > >> + >> + return d; >> +} >> +EXPORT_SYMBOL_GPL(iommu_msi_mapping_desc_to_domain); >> diff --git a/include/linux/dma-reserved-iommu.h >> b/include/linux/dma-reserved-iommu.h >> index 8722131..8373929 100644 >> --- a/include/linux/dma-reserved-iommu.h >> +++ b/include/linux/dma-reserved-iommu.h >> @@ -19,6 +19,7 @@ >> #include >> >> struct iommu_domain; >> +struct msi_desc; >> >> #ifdef CONFIG_IOMMU_DMA_RESERVED >> >> @@ -70,6 +71,17 @@ int iommu_get_reserved_iova(struct iommu_domain >> *domain, >> * if the binding ref count is null, destroy the reserved mapping >> */ >> void iommu_put_reserved_iova(struct iommu_domain *domain, >> phys_addr_t addr); >> + >> +/** >> + * iommu_msi_mapping_desc_to_domain: in case the MSI originates from >> a device >> + * upstream to an IOMMU and this IOMMU translates the MSI transaction, >> + * this function returns the iommu domain the MSI doorbell address >> must be >> + * mapped in. Else it returns NULL. >> + * >> + * @desc: msi desc handle >> + */ >> +struct iommu_domain *iommu_msi_mapping_desc_to_domain(struct msi_desc >> *desc); >> + >> #else >> >> static inline int >> @@ -93,5 +105,11 @@ static inline int iommu_get_reserved_iova(struct >> iommu_domain *domain, >> static inline void iommu_put_reserved_iova(struct iommu_domain *domain, >> phys_addr_t addr) {} >> >> +static inline struct iommu_domain * >> +iommu_msi_mapping_desc_to_domain(struct msi_desc *desc) >> +{ >> + return NULL; >> +} >> + >> #endif /* CONFIG_IOMMU_DMA_RESERVED */ >> #endif /* __DMA_RESERVED_IOMMU_H */ >> >