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Handle Appolo Lake errata APL31.

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If the workaround is activated, always send IPI for wake up, not rely
on the write to the monitor line.  This fixes Appolo Lake machines
early hang in sched_bind(), without requiring user to manually select
idle method.

Sponsored by:	The FreeBSD Foundation
MFC after:	1 week
This commit is contained in:
Konstantin Belousov 2018-04-26 18:24:31 +00:00
parent a5f472c579
commit 3f3937b4ae
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=333026
1 changed files with 13 additions and 1 deletions
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14
sys/x86/x86/cpu_machdep.c
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@ -575,6 +575,11 @@ cpu_idle(int busy)
busy, curcpu);
}
static int cpu_idle_apl31_workaround;
SYSCTL_INT(_machdep, OID_AUTO, idle_apl31, CTLFLAG_RW,
&cpu_idle_apl31_workaround, 0,
"Appolo Lake APL31 MWAIT bug workaround");
int
cpu_idle_wakeup(int cpu)
{
@ -586,7 +591,7 @@ cpu_idle_wakeup(int cpu)
return (0);
case STATE_MWAIT:
atomic_store_int(state, STATE_RUNNING);
return (1);
return (cpu_idle_apl31_workaround ? 0 : 1);
case STATE_RUNNING:
return (1);
default:
@ -689,6 +694,13 @@ cpu_idle_tun(void *unused __unused)
if (TUNABLE_STR_FETCH("machdep.idle", tunvar, sizeof(tunvar)))
cpu_idle_selector(tunvar);
if (cpu_vendor_id == CPU_VENDOR_INTEL && cpu_id == 0x506c9) {
/*
* Appolo Lake errata APL31.
*/
cpu_idle_apl31_workaround = 1;
}
TUNABLE_INT_FETCH("machdep.idle_apl31", &cpu_idle_apl31_workaround);
}
SYSINIT(cpu_idle_tun, SI_SUB_CPU, SI_ORDER_MIDDLE, cpu_idle_tun, NULL);