From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Auger Subject: [RFC v3 07/15] iommu: iommu_get/put_single_reserved Date: Fri, 12 Feb 2016 08:13:09 +0000 Message-ID: <1455264797-2334-8-git-send-email-eric.auger@linaro.org> References: <1455264797-2334-1-git-send-email-eric.auger@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1455264797-2334-1-git-send-email-eric.auger@linaro.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: eric.auger@st.com, eric.auger@linaro.org, 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, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org Cc: Thomas.Lendacky@amd.com, brijesh.singh@amd.com, patches@linaro.org, Manish.Jaggi@caviumnetworks.com, linux-kernel@vger.kernel.org, iommu@lists.linux-foundation.org, leo.duran@amd.com, sherry.hurwitz@amd.com List-Id: iommu@lists.linux-foundation.org This patch introduces iommu_get/put_single_reserved. iommu_get_single_reserved allows to allocate a new reserved iova page and map it onto the physical page that contains a given physical address. It returns the iova that is mapped onto the provided physical address. Hence the physical address passed in argument does not need to be aligned. In case a mapping already exists between both pages, the IOVA mapped to the PA is directly returned. Each time an iova is successfully returned a binding ref count is incremented. iommu_put_single_reserved decrements the ref count and when this latter is null, the mapping is destroyed and the iova is released. Signed-off-by: Eric Auger Signed-off-by: Ankit Jindal Signed-off-by: Pranavkumar Sawargaonkar Signed-off-by: Bharat Bhushan --- v2 -> v3: - remove static implementation of iommu_get_single_reserved & iommu_put_single_reserved when CONFIG_IOMMU_API is not set v1 -> v2: - previously a VFIO API, named vfio_alloc_map/unmap_free_reserved_iova --- drivers/iommu/iommu.c | 21 +++++++++++++++++++++ include/linux/iommu.h | 20 ++++++++++++++++++++ 2 files changed, 41 insertions(+) diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index a994f34..14ebde1 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -1415,6 +1415,27 @@ size_t iommu_unmap(struct iommu_domain *domain, unsigned long iova, size_t size) return unmapped; } EXPORT_SYMBOL_GPL(iommu_unmap); +int iommu_get_single_reserved(struct iommu_domain *domain, + phys_addr_t addr, int prot, + dma_addr_t *iova) +{ + if (!domain->ops->get_single_reserved) + return -ENODEV; + + return domain->ops->get_single_reserved(domain, addr, prot, iova); + +} +EXPORT_SYMBOL_GPL(iommu_get_single_reserved); + +void iommu_put_single_reserved(struct iommu_domain *domain, + dma_addr_t iova) +{ + if (!domain->ops->put_single_reserved) + return; + + domain->ops->put_single_reserved(domain, iova); +} +EXPORT_SYMBOL_GPL(iommu_put_single_reserved); size_t default_iommu_map_sg(struct iommu_domain *domain, unsigned long iova, struct scatterlist *sg, unsigned int nents, int prot) diff --git a/include/linux/iommu.h b/include/linux/iommu.h index 2d1f155..1e00c1b 100644 --- a/include/linux/iommu.h +++ b/include/linux/iommu.h @@ -201,6 +201,21 @@ struct iommu_ops { unsigned long order); /* frees the reserved iova domain */ void (*free_reserved_iova_domain)(struct iommu_domain *domain); + /** + * allocate a reserved iova page and bind it onto the page that + * contains a physical address (@addr), returns the @iova bound to + * @addr. In case the 2 pages already are bound simply return @iova + * and increment a ref count. + */ + int (*get_single_reserved)(struct iommu_domain *domain, + phys_addr_t addr, int prot, + dma_addr_t *iova); + /** + * decrement a ref count of the iova page. If null, unmap the iova page + * and release the iova + */ + void (*put_single_reserved)(struct iommu_domain *domain, + dma_addr_t iova); #ifdef CONFIG_OF_IOMMU int (*of_xlate)(struct device *dev, struct of_phandle_args *args); @@ -276,6 +291,11 @@ extern int iommu_alloc_reserved_iova_domain(struct iommu_domain *domain, dma_addr_t iova, size_t size, unsigned long order); extern void iommu_free_reserved_iova_domain(struct iommu_domain *domain); +extern int iommu_get_single_reserved(struct iommu_domain *domain, + phys_addr_t paddr, int prot, + dma_addr_t *iova); +extern void iommu_put_single_reserved(struct iommu_domain *domain, + dma_addr_t iova); struct device *iommu_device_create(struct device *parent, void *drvdata, const struct attribute_group **groups, const char *fmt, ...) __printf(4, 5); -- 1.9.1