From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thierry Reding Subject: [PATCH 1/2] iommu: Implement of_iommu_get_resv_regions() Date: Thu, 29 Aug 2019 13:14:06 +0200 Message-ID: <20190829111407.17191-2-thierry.reding@gmail.com> References: <20190829111407.17191-1-thierry.reding@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190829111407.17191-1-thierry.reding@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Joerg Roedel Cc: Rob Herring , Frank Rowand , Will Deacon , Robin Murphy , iommu@lists.linux-foundation.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org From: Thierry Reding This is an implementation that IOMMU drivers can use to obtain reserved memory regions from a device tree node. It uses the reserved-memory DT bindings to find the regions associated with a given device. These regions will be used to create 1:1 mappings in the IOMMU domain that the devices will be attached to. Cc: Rob Herring Cc: Frank Rowand Cc: devicetree@vger.kernel.org Signed-off-by: Thierry Reding --- drivers/iommu/of_iommu.c | 39 +++++++++++++++++++++++++++++++++++++++ include/linux/of_iommu.h | 8 ++++++++ 2 files changed, 47 insertions(+) diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c index 614a93aa5305..0d47f626b854 100644 --- a/drivers/iommu/of_iommu.c +++ b/drivers/iommu/of_iommu.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -225,3 +226,41 @@ const struct iommu_ops *of_iommu_configure(struct device *dev, return ops; } + +/** + * of_iommu_get_resv_regions - reserved region driver helper for device tree + * @dev: device for which to get reserved regions + * @list: reserved region list + * + * IOMMU drivers can use this to implement their .get_resv_regions() callback + * for memory regions attached to a device tree node. See the reserved-memory + * device tree bindings on how to use these: + * + * Documentation/devicetree/bindings/reserved-memory/reserved-memory.txt + */ +void of_iommu_get_resv_regions(struct device *dev, struct list_head *list) +{ + struct of_phandle_iterator it; + int err; + + of_for_each_phandle(&it, err, dev->of_node, "memory-region", NULL, 0) { + struct iommu_resv_region *region; + struct resource res; + + err = of_address_to_resource(it.node, 0, &res); + if (err < 0) { + dev_err(dev, "failed to parse memory region %pOF: %d\n", + it.node, err); + continue; + } + + region = iommu_alloc_resv_region(res.start, resource_size(&res), + IOMMU_READ | IOMMU_WRITE, + IOMMU_RESV_DIRECT_RELAXABLE); + if (!region) + continue; + + list_add_tail(®ion->list, list); + } +} +EXPORT_SYMBOL(of_iommu_get_resv_regions); diff --git a/include/linux/of_iommu.h b/include/linux/of_iommu.h index f3d40dd7bb66..fa16b26f55bc 100644 --- a/include/linux/of_iommu.h +++ b/include/linux/of_iommu.h @@ -15,6 +15,9 @@ extern int of_get_dma_window(struct device_node *dn, const char *prefix, extern const struct iommu_ops *of_iommu_configure(struct device *dev, struct device_node *master_np); +extern void of_iommu_get_resv_regions(struct device *dev, + struct list_head *list); + #else static inline int of_get_dma_window(struct device_node *dn, const char *prefix, @@ -30,6 +33,11 @@ static inline const struct iommu_ops *of_iommu_configure(struct device *dev, return NULL; } +static inline void of_iommu_get_resv_regions(struct device *dev, + struct list_head *list) +{ +} + #endif /* CONFIG_OF_IOMMU */ #endif /* __OF_IOMMU_H */ -- 2.22.0