[linux-yocto] [PATCH v5.2] nvme-pci: Set the prp2 correctly when using more than 4k page

[Bruce Ashfield]

In message: [PATCH v5.2] nvme-pci: Set the prp2 correctly when using more than 4k page
on 19/10/2019 Kevin Hao wrote:

> commit a4f40484e7f1dff56bb9f286cc59ffa36e0259eb from
> git://git.infradead.org/nvme.git
> 
> In the current code, the nvme is using a fixed 4k PRP entry size,
> but if the kernel use a page size which is more than 4k, we should
> consider the situation that the bv_offset may be larger than the
> dev->ctrl.page_size. Otherwise we may miss setting the prp2 and then
> cause the command can't be executed correctly.
> 
> Fixes: dff824b2aadb ("nvme-pci: optimize mapping of small single segment requests")
> Cc: stable at vger.kernel.org
> Reviewed-by: Christoph Hellwig <hch at lst.de>
> Signed-off-by: Kevin Hao <haokexin at gmail.com>
> Signed-off-by: Keith Busch <kbusch at kernel.org>
> ---
> Hi Bruce,
> 
> This patch has already been merged into nvme-5.4 and I also CCed stable at vger.kernel.org,
> so in theory it could propagate to linux-yocto via the stable update.
> But this issue cause a critical malfunction for the nvme interface and
> block our validation for it. So I would like to pick this patch ASAP.
> We should merge this into v5.2/standard/base branch.

No problem. I was just looking at the queue, and since this was already
reviewed upstream and safe .. I jumped it to the front and have merged
and pushed it to the repo.

Bruce

> 
>  drivers/nvme/host/pci.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
> index 4b181969c432..869f462e6b6e 100644
> --- a/drivers/nvme/host/pci.c
> +++ b/drivers/nvme/host/pci.c
> @@ -773,7 +773,8 @@ static blk_status_t nvme_setup_prp_simple(struct nvme_dev *dev,
>  		struct bio_vec *bv)
>  {
>  	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
> -	unsigned int first_prp_len = dev->ctrl.page_size - bv->bv_offset;
> +	unsigned int offset = bv->bv_offset & (dev->ctrl.page_size - 1);
> +	unsigned int first_prp_len = dev->ctrl.page_size - offset;
>  
>  	iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0);
>  	if (dma_mapping_error(dev->dev, iod->first_dma))
> -- 
> 2.14.4
>