From: Stephen Warren <swarren@xxxxxxxxxxxxx>
Date: Thu, 3 Jan 2019 10:23:23 -0700
> From: Stephen Warren <swarren@xxxxxxxxxx>
>
> This patch solves a crash at the time of mlx4 driver unload or system
> shutdown. The crash occurs because dma_alloc_coherent() returns one
> value in mlx4_alloc_icm_coherent(), but a different value is passed to
> dma_free_coherent() in mlx4_free_icm_coherent(). In turn this is because
> when allocated, that pointer is passed to sg_set_buf() to record it,
> then when freed it is re-calculated by calling
> lowmem_page_address(sg_page()) which returns a different value. Solve
> this by recording the value that dma_alloc_coherent() returns, and
> passing this to dma_free_coherent().
>
> This patch is roughly equivalent to commit 378efe798ecf ("RDMA/hns: Get
> rid of page operation after dma_alloc_coherent").
>
> Based-on-code-from: Christoph Hellwig <hch@xxxxxx>
> Signed-off-by: Stephen Warren <swarren@xxxxxxxxxx>
Applied.
