1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-or-later 2*4882a593Smuzhiyun /* 3*4882a593Smuzhiyun * Hypervisor Maintenance Interrupt (HMI) handling. 4*4882a593Smuzhiyun * 5*4882a593Smuzhiyun * Copyright 2015 IBM Corporation 6*4882a593Smuzhiyun * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> 7*4882a593Smuzhiyun */ 8*4882a593Smuzhiyun 9*4882a593Smuzhiyun #undef DEBUG 10*4882a593Smuzhiyun 11*4882a593Smuzhiyun #include <linux/types.h> 12*4882a593Smuzhiyun #include <linux/compiler.h> 13*4882a593Smuzhiyun #include <asm/paca.h> 14*4882a593Smuzhiyun #include <asm/hmi.h> 15*4882a593Smuzhiyun #include <asm/processor.h> 16*4882a593Smuzhiyun wait_for_subcore_guest_exit(void)17*4882a593Smuzhiyunvoid wait_for_subcore_guest_exit(void) 18*4882a593Smuzhiyun { 19*4882a593Smuzhiyun int i; 20*4882a593Smuzhiyun 21*4882a593Smuzhiyun /* 22*4882a593Smuzhiyun * NULL bitmap pointer indicates that KVM module hasn't 23*4882a593Smuzhiyun * been loaded yet and hence no guests are running. 24*4882a593Smuzhiyun * If no KVM is in use, no need to co-ordinate among threads 25*4882a593Smuzhiyun * as all of them will always be in host and no one is going 26*4882a593Smuzhiyun * to modify TB other than the opal hmi handler. 27*4882a593Smuzhiyun * Hence, just return from here. 28*4882a593Smuzhiyun */ 29*4882a593Smuzhiyun if (!local_paca->sibling_subcore_state) 30*4882a593Smuzhiyun return; 31*4882a593Smuzhiyun 32*4882a593Smuzhiyun for (i = 0; i < MAX_SUBCORE_PER_CORE; i++) 33*4882a593Smuzhiyun while (local_paca->sibling_subcore_state->in_guest[i]) 34*4882a593Smuzhiyun cpu_relax(); 35*4882a593Smuzhiyun } 36*4882a593Smuzhiyun wait_for_tb_resync(void)37*4882a593Smuzhiyunvoid wait_for_tb_resync(void) 38*4882a593Smuzhiyun { 39*4882a593Smuzhiyun if (!local_paca->sibling_subcore_state) 40*4882a593Smuzhiyun return; 41*4882a593Smuzhiyun 42*4882a593Smuzhiyun while (test_bit(CORE_TB_RESYNC_REQ_BIT, 43*4882a593Smuzhiyun &local_paca->sibling_subcore_state->flags)) 44*4882a593Smuzhiyun cpu_relax(); 45*4882a593Smuzhiyun } 46