block: kill ISA_DMA_THRESHOLD usage
block uses ISA_DMA_THRESHOLD for BLK_BOUNCE_ISA. Only SCSI uses ISA_DMA_THRESHOLD for ancient drivers with non-zero unchecked_isa_dma. Nowadays drivers (and subsystems) use dma_mask properly instead of ISA_DMA_THRESHOLD. Documentation/scsi/scsi_mid_low_api.txt says: unchecked_isa_dma - 1=>only use bottom 16 MB of ram (ISA DMA addressing restriction), 0=>can use full 32 bit (or better) DMA address space So block simply uses DMA_BIT_MASK(24) for BLK_BOUNCE_ISA for SCSI. Signed-off-by:FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by:
James Bottomley <James.Bottomley@suse.de> Signed-off-by:
Jens Axboe <jaxboe@fusionio.com>
parent
b375a612
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