[PATCH] tpm: ibmvtpm: Make use of dma_alloc_coherent()

[Jarkko Sakkinen]

On Mon, 2021-10-11 at 00:01 +0800, Cai Huoqing wrote:
> Replacing kmalloc/kfree/get_zeroed_page/free_page/dma_map_single/
  ~~~~~~~~~
  Replace

> dma_unmap_single() with dma_alloc_coherent/dma_free_coherent()
> helps to reduce code size, and simplify the code, and coherent
> DMA will not clear the cache every time.
> 
> Signed-off-by: Cai Huoqing <caihuoqing at baidu.com>

If this does not do functionally anything useful, there's no
reason to apply this.

It is also missing information why the substitution is possible.

Field tested code is better than clean code, i.e. we don not
risk at having possible new regressions just for a bit nicer
layout...

/Jarkko