cxl: fix NULL dereference in cxl_context_init() on PowerVM guests

[Michael Ellerman]

On Thu, 2016-28-07 at 05:39:41 UTC, Andrew Donnellan wrote:
> Commit f67a6722d650 ("cxl: Workaround PE=0 hardware limitation in Mellanox
> CX4") added a "min_pe" field to struct cxl_service_layer_ops, to allow us
> to work around a Mellanox CX-4 hardware limitation.
> 
> When allocating the PE number in cxl_context_init(), we read from
> ctx->afu->adapter->native->sl_ops->min_pe to get the minimum PE number.
> Unsurprisingly, in a PowerVM guest ctx->afu->adapter->native is NULL, and
> guests don't have a cxl_service_layer_ops struct anywhere.
> 
> Move min_pe from struct cxl_service_layer_ops to struct cxl so it's
> accessible in both native and PowerVM environments. For the Mellanox CX-4,
> set the min_pe value in set_sl_ops().
> 
> Fixes: f67a6722d650 ("cxl: Workaround PE=0 hardware limitation in Mellanox CX4")
> Reported-by: Frederic Barrat <fbarrat at linux.vnet.ibm.com>
> Signed-off-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>
> Acked-by: Ian Munsie <imunsie at au1.ibm.com>
> Reviewed-by: Frederic Barrat <fbarrat at linux.vnet.ibm.com>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/164793379ad3b7ef5fc5a28260

cheers