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*参照元 [#y6a52341] #backlinks *説明 [#i3c4a9fe] -パス: [[linux-4.4.1/]] -パス: [[linux-4.4.1/drivers/iommu/dma-iommu.c]] -FIXME: これは何？ --説明 **引数 [#p5014b5f] -struct iommu_domain *domain -- --[[linux-4.4.1/iommu_domain]] -dma_addr_t base -- --[[linux-4.4.1/dma_addr_t]] -u64 size -- **返り値 [#s5657385] -int -- **参考 [#q86b8eed] *実装 [#e196c8a4] /** * iommu_dma_init_domain - Initialise a DMA mapping domain * @domain: IOMMU domain previously prepared by iommu_get_dma_cookie() * @base: IOVA at which the mappable address space starts * @size: Size of IOVA space * * @base and @size should be exact multiples of IOMMU page granularity to * avoid rounding surprises. If necessary, we reserve the page at address 0 * to ensure it is an invalid IOVA. It is safe to reinitialise a domain, but * any change which could make prior IOVAs invalid will fail. */ int iommu_dma_init_domain(struct iommu_domain *domain, dma_addr_t base, u64 size) { struct iova_domain *iovad = domain->iova_cookie; unsigned long order, base_pfn, end_pfn; - --[[linux-4.4.1/iova_domain]] if (!iovad) return -ENODEV; /* Use the smallest supported page size for IOVA granularity */ order = __ffs(domain->ops->pgsize_bitmap); base_pfn = max_t(unsigned long, 1, base >> order); end_pfn = (base + size - 1) >> order; - --[[linux-4.4.1/__ffs()]] --[[linux-4.4.1/max_t()]] /* Check the domain allows at least some access to the device... */ if (domain->geometry.force_aperture) { if (base > domain->geometry.aperture_end || base + size <= domain->geometry.aperture_start) { pr_warn("specified DMA range outside IOMMU capability\n"); return -EFAULT; } /* ...then finally give it a kicking to make sure it fits */ base_pfn = max_t(unsigned long, base_pfn, domain->geometry.aperture_start >> order); end_pfn = min_t(unsigned long, end_pfn, domain->geometry.aperture_end >> order); } - --[[linux-4.4.1/pr_warn()]] --[[linux-4.4.1/min_t()]] /* All we can safely do with an existing domain is enlarge it */ if (iovad->start_pfn) { if (1UL << order != iovad->granule || base_pfn != iovad->start_pfn || end_pfn < iovad->dma_32bit_pfn) { pr_warn("Incompatible range for DMA domain\n"); return -EFAULT; } iovad->dma_32bit_pfn = end_pfn; } else { init_iova_domain(iovad, 1UL << order, base_pfn, end_pfn); } - --[[linux-4.4.1/init_iova_domain()]] return 0; } EXPORT_SYMBOL(iommu_dma_init_domain); - --[[linux-4.4.1/EXPORT_SYMBOL()]] *コメント [#e2b6d751]
