diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index c68a1f072c31..8cdb2436f4d0 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -352,6 +352,34 @@ static int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, return iova_reserve_iommu_regions(dev, domain); } +/* + * Should be called prior to using dma-apis + */ +int iommu_dma_reserve_iova(struct device *dev, dma_addr_t base, + u64 size) +{ + struct iommu_domain *domain; + struct iommu_dma_cookie *cookie; + struct iova_domain *iovad; + unsigned long pfn_lo, pfn_hi; + + domain = iommu_get_domain_for_dev(dev); + if (!domain || !domain->iova_cookie) + return -EINVAL; + + cookie = domain->iova_cookie; + iovad = &cookie->iovad; + + /* iova will be freed automatically by put_iova_domain() */ + pfn_lo = iova_pfn(iovad, base); + pfn_hi = iova_pfn(iovad, base + size - 1); + if (!reserve_iova(iovad, pfn_lo, pfn_hi)) + return -EINVAL; + + return 0; +} +EXPORT_SYMBOL(iommu_dma_reserve_iova); + /** * dma_info_to_prot - Translate DMA API directions and attributes to IOMMU API * page flags. diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h index 2112f21f73d8..79eef7cf9013 100644 --- a/include/linux/dma-iommu.h +++ b/include/linux/dma-iommu.h @@ -37,6 +37,9 @@ void iommu_dma_compose_msi_msg(struct msi_desc *desc, void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list); +int iommu_dma_reserve_iova(struct device *dev, dma_addr_t base, + u64 size); + #else /* CONFIG_IOMMU_DMA */ struct iommu_domain; @@ -78,5 +81,11 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he { } +static inline int iommu_dma_reserve_iova(struct device *dev, dma_addr_t base, + u64 size) +{ + return -ENODEV; +} + #endif /* CONFIG_IOMMU_DMA */ #endif /* __DMA_IOMMU_H */