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

From: Zhou Wang
Date: Sun Aug 02 2020 - 21:13:05 EST


On 2020/8/2 22:52, Jia-Ju Bai wrote:
> In qm_qp_ctx_cfg(), "sqc" and "aeqc" are mapped to streaming DMA:
> eqc_dma = dma_map_single(..., eqc, ...);
> ......
> aeqc_dma = dma_map_single(..., aeqc, ...);

Only sqc, cqc will be configured in qm_qp_ctx_cfg.

>
> Then "sqc" and "aeqc" are accessed at many places, such as:
> eqc->base_l = cpu_to_le32(lower_32_bits(qm->eqe_dma));
> eqc->base_h = cpu_to_le32(upper_32_bits(qm->eqe_dma));
> ......
> aeqc->base_l = cpu_to_le32(lower_32_bits(qm->aeqe_dma));
> aeqc->base_h = cpu_to_le32(upper_32_bits(qm->aeqe_dma));

There are sqc, cqc, eqc, aeqc, you seems misunderstand them.

>
> 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.

In qm_qp_ctx_cfg, sqc/cqc memory will be allocated and related mailbox will be sent
to hardware. In qm_eq_ctx_cfg, eqc/aeqc related operations will be done.

So there is no problem here :)

Thanks,
Zhou

>
>
> Best wishes,
> Jia-Ju Bai
>
>