powerpc: Rework IPI message processing

Summary:
There's no need to use a while loop in the IPI handler, the message list
is cached once and processed.  Instead, since the existing code calls
ffs(), sort the handlers, and use a simple 'if' sequence.

Reviewed By: nwhitehorn
Differential Revision: https://reviews.freebsd.org/D30018
This commit is contained in:
Justin Hibbits 2021-04-26 19:10:41 -05:00
parent 9aad27931e
commit 7ed09a6778

View File

@ -299,49 +299,43 @@ powerpc_ipi_handler(void *arg)
{
u_int cpuid;
uint32_t ipimask;
int msg;
CTR2(KTR_SMP, "%s: MSR 0x%08x", __func__, mfmsr());
ipimask = atomic_readandclear_32(&(pcpup->pc_ipimask));
if (ipimask == 0)
return (FILTER_STRAY);
while ((msg = ffs(ipimask) - 1) != -1) {
ipimask &= ~(1u << msg);
switch (msg) {
case IPI_AST:
CTR1(KTR_SMP, "%s: IPI_AST", __func__);
break;
case IPI_PREEMPT:
CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
sched_preempt(curthread);
break;
case IPI_RENDEZVOUS:
CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
smp_rendezvous_action();
break;
case IPI_STOP:
if (ipimask & (1 << IPI_AST)) {
CTR1(KTR_SMP, "%s: IPI_AST", __func__);
}
if (ipimask & (1 << IPI_PREEMPT)) {
CTR1(KTR_SMP, "%s: IPI_PREEMPT", __func__);
sched_preempt(curthread);
}
if (ipimask & (1 << IPI_RENDEZVOUS)) {
CTR1(KTR_SMP, "%s: IPI_RENDEZVOUS", __func__);
smp_rendezvous_action();
}
if (ipimask & (1 << IPI_STOP)) {
/*
* IPI_STOP_HARD is mapped to IPI_STOP so it is not
* necessary to add such case in the switch.
*/
CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
__func__);
cpuid = PCPU_GET(cpuid);
savectx(&stoppcbs[cpuid]);
CPU_SET_ATOMIC(cpuid, &stopped_cpus);
while (!CPU_ISSET(cpuid, &started_cpus))
cpu_spinwait();
CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
CPU_CLR_ATOMIC(cpuid, &started_cpus);
CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
break;
case IPI_HARDCLOCK:
CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
hardclockintr();
break;
}
/*
* IPI_STOP_HARD is mapped to IPI_STOP so it is not
* necessary to add such case.
*/
CTR1(KTR_SMP, "%s: IPI_STOP or IPI_STOP_HARD (stop)",
__func__);
cpuid = PCPU_GET(cpuid);
savectx(&stoppcbs[cpuid]);
CPU_SET_ATOMIC(cpuid, &stopped_cpus);
while (!CPU_ISSET(cpuid, &started_cpus))
cpu_spinwait();
CPU_CLR_ATOMIC(cpuid, &stopped_cpus);
CPU_CLR_ATOMIC(cpuid, &started_cpus);
CTR1(KTR_SMP, "%s: IPI_STOP (restart)", __func__);
}
if (ipimask & (1 << IPI_HARDCLOCK)) {
CTR1(KTR_SMP, "%s: IPI_HARDCLOCK", __func__);
hardclockintr();
}
return (FILTER_HANDLED);