[v2] cxl: Check if PSL data-cache is available before issue flush request

[Michael Ellerman]

On Thu, 2018-02-15 at 15:49:24 UTC, Vaibhav Jain wrote:
> PSL9D doesn't have a data-cache that needs to be flushed before
> resetting the card. However when cxl tries to flush data-cache on such
> a card, it times-out as PSL_Control register never indicates flush
> operation complete due to missing data-cache. This is usually
> indicated in the kernel logs with this message:
> 
> "WARNING: cache flush timed out"
> 
> To fix this the patch checks PSL_Debug register CDC-Field(BIT:27)
> which indicates the absence of a data-cache and sets a flag
> 'no_data_cache' in 'struct cxl_native' to indicate this. When
> cxl_data_cache_flush() is called it checks the flag and if set bails
> out early without requesting a data-cache flush operation to the PSL.
> 
> Signed-off-by: Vaibhav Jain <vaibhav at linux.vnet.ibm.com>
> Acked-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>
> Acked-by: Frederic Barrat <fbarrat at linux.vnet.ibm.com>

Applied to powerpc next, thanks.

https://git.kernel.org/powerpc/c/94322ed8e857e3b2a33cf75118051a

cheers