The attached patch enables ESL=1 STOP2 for cpuhotplug. This is a debug patch that we could carry now until STOP states are discovered from device tree.
Test run: [ 151.670021] CPU8 going offline with request psscr 00000000003f0332 [ 151.719856] CPU 8 offline: Remove Rx thread [ 189.200410] CPU8 coming online with psscr 20000000003f0332, srr1 9000000000261001 We request ESL=EC=1 and STOP2 and successfully wakeup from that state using IPI from XIVE. --Vaidy
