Re: [PATCH 3/4] ntb_perf: pass correct struct device to dma_alloc_coherent

[Logan Gunthorpe]

On 2020-02-05 10:16 a.m., Arindam Nath wrote:
> From: Sanjay R Mehta <sanju.mehta@xxxxxxx>
> 
> Currently, ntb->dev is passed to dma_alloc_coherent
> and dma_free_coherent calls. The returned dma_addr_t
> is the CPU physical address. This works fine as long
> as IOMMU is disabled. But when IOMMU is enabled, we
> need to make sure that IOVA is returned for dma_addr_t.
> So the correct way to achieve this is by changing the
> first parameter of dma_alloc_coherent() as ntb->pdev->dev
> instead.
> 
> Fixes: 5648e56 ("NTB: ntb_perf: Add full multi-port NTB API support")
> Signed-off-by: Sanjay R Mehta <sanju.mehta@xxxxxxx>
> Signed-off-by: Arindam Nath <arindam.nath@xxxxxxx>

Ugh, this has been fixed repeatedly and independently by a number of
people. I sent a fix[1] in more than a year ago and Sanjay repeated the
effort a couple months ago[2].

I have the same feed back for you that I had for him: once we fix the
bug we should also go in and remove the now unnecessary
dma_coerce_mask_and_coherent() calls in the drivers at the same time
seeing it no longer makes any sense. My patch did this already.

Thanks,

Logan

[1] https://lore.kernel.org/lkml/20190109192233.5752-3-logang@xxxxxxxxxxxx/
[2]
https://lore.kernel.org/lkml/1575983255-70377-1-git-send-email-Sanju.Mehta@xxxxxxx/