linux-zen-server/arch/powerpc/kvm/book3s_hv_hmi.c

51 lines
1.2 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Hypervisor Maintenance Interrupt (HMI) handling.
*
* Copyright 2015 IBM Corporation
* Author: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
*/
#undef DEBUG
#include <linux/types.h>
#include <linux/compiler.h>
#include <asm/paca.h>
#include <asm/hmi.h>
#include <asm/processor.h>
void wait_for_subcore_guest_exit(void)
{
int i;
/*
* NULL bitmap pointer indicates that KVM module hasn't
* been loaded yet and hence no guests are running, or running
* on POWER9 or newer CPU.
*
* If no KVM is in use, no need to co-ordinate among threads
* as all of them will always be in host and no one is going
* to modify TB other than the opal hmi handler.
*
* POWER9 and newer don't need this synchronisation.
*
* Hence, just return from here.
*/
if (!local_paca->sibling_subcore_state)
return;
for (i = 0; i < MAX_SUBCORE_PER_CORE; i++)
while (local_paca->sibling_subcore_state->in_guest[i])
cpu_relax();
}
void wait_for_tb_resync(void)
{
if (!local_paca->sibling_subcore_state)
return;
while (test_bit(CORE_TB_RESYNC_REQ_BIT,
&local_paca->sibling_subcore_state->flags))
cpu_relax();
}