1 /* 2 * Hypervisor Maintenance Interrupt (HMI) handling. 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2 of the License, or 7 * (at your option) any later version. 8 * 9 * This program is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program. 16 * 17 * Copyright 2015 IBM Corporation 18 * Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> 19 */ 20 21 #undef DEBUG 22 23 #include <linux/types.h> 24 #include <linux/compiler.h> 25 #include <asm/paca.h> 26 #include <asm/hmi.h> 27 #include <asm/processor.h> 28 29 void wait_for_subcore_guest_exit(void) 30 { 31 int i; 32 33 /* 34 * NULL bitmap pointer indicates that KVM module hasn't 35 * been loaded yet and hence no guests are running. 36 * If no KVM is in use, no need to co-ordinate among threads 37 * as all of them will always be in host and no one is going 38 * to modify TB other than the opal hmi handler. 39 * Hence, just return from here. 40 */ 41 if (!local_paca->sibling_subcore_state) 42 return; 43 44 for (i = 0; i < MAX_SUBCORE_PER_CORE; i++) 45 while (local_paca->sibling_subcore_state->in_guest[i]) 46 cpu_relax(); 47 } 48 49 void wait_for_tb_resync(void) 50 { 51 if (!local_paca->sibling_subcore_state) 52 return; 53 54 while (test_bit(CORE_TB_RESYNC_REQ_BIT, 55 &local_paca->sibling_subcore_state->flags)) 56 cpu_relax(); 57 } 58