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