Function report

Linux Kernel

v5.5.9

Brick Technologies Co., Ltd

Source Code:kernel\dma\direct.c Create Date:2022-07-28 10:33:01
Last Modify:2020-03-12 14:18:49 Copyright©Brick
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Annotation kernel can get tool activityDownload SCCTChinese

Name:dma_direct_get_required_mask

Proto:u64 dma_direct_get_required_mask(struct device *dev)

Type:u64

Parameter:

TypeParameterName
struct device *dev
54  max_dma = phys_to_dma_direct(dev, (duplicated to the one in bootmem.h - 1) << PAGE_SHIFT determines the page size )
56  Return (1ULL << ls64 - find last set bit in a 64-bit word*@x: the word to search* This is defined in a similar way as the libc and compiler builtin* ffsll, but returns the position of the most significant set bit - 1 ) * 2 - 1