[BUG] crypto: qat: accessing the data mapped to streaming DMA

From: Jia-Ju Bai
Date: Sun Aug 02 2020 - 10:37:24 EST

In qat_alg_sgl_to_bufl(), "bufl" and "buflout" are mapped to streaming DMA:
 blp = dma_map_single(dev, bufl, sz, DMA_TO_DEVICE);
 bloutp = dma_map_single(dev, buflout, sz_out, DMA_TO_DEVICE);

Then "bufl" and "buflout" are accessed at some places, such as:
 bufl->bufers[y].len = sg->length;
 bufl->num_bufs = sg_nctr;
 bufers = buflout->bufers;
 buflout->num_bufs = sg_nctr;

These accesses may cause data inconsistency between CPU cache and hardware.

I am not sure how to properly fix this problem, and thus I only report it.

Best wishes,
Jia-Ju Bai