git: e0cc1ce7c086 - stable/12 - smp_targeted_tlb_shootdown has to pin the CPU on i386

From: Andriy Gapon <avg_at_FreeBSD.org>
Date: Tue, 25 Jan 2022 10:39:06 UTC
The branch stable/12 has been updated by avg:

URL: https://cgit.FreeBSD.org/src/commit/?id=e0cc1ce7c0866d6a5c42ef09cfca9582c4a8343c

commit e0cc1ce7c0866d6a5c42ef09cfca9582c4a8343c
Author:     Andriy Gapon <avg@FreeBSD.org>
AuthorDate: 2022-01-25 10:34:08 +0000
Commit:     Andriy Gapon <avg@FreeBSD.org>
CommitDate: 2022-01-25 10:34:08 +0000

    smp_targeted_tlb_shootdown has to pin the CPU on i386
    
    This should fix a regression in 1820ca215461 which happened
    because pmap -> shootdown contracts on amd64 and i386 diverged.
    On amd64 the pmap code always pins the CPU before calling the shootdown
    code and expects it to unpin on return.
    On i386 the pmap code either has pins and unpins around the shootdown
    calls or does not pin at all.
    This change should account for that difference.
    
    In main and stable/13 the contracts are also different, but the
    shootdown code is split into the i386 and amd64 variants and each
    variant is tailored towards the platform's pmap.
    
    PR:             261338
    Reported by:    Dmitry K. <thedix@yandex.ru>
    Debugged by:    Dmitry K. <thedix@yandex.ru>
    Tested by:      Dmitry K. <thedix@yandex.ru>
    Fixes:  1820ca215461 MFC r368649 / 3fd989da by kib: amd64 pmap: fix PCID mode invalidations
    Reviewed by:    kib
    X-Pointyhat to: avg
    Differential Revision:  https://reviews.freebsd.org/D33980
---
 sys/x86/x86/mp_x86.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/sys/x86/x86/mp_x86.c b/sys/x86/x86/mp_x86.c
index 2108d448bb9a..57cea8c7a07a 100644
--- a/sys/x86/x86/mp_x86.c
+++ b/sys/x86/x86/mp_x86.c
@@ -1678,6 +1678,10 @@ smp_targeted_tlb_shootdown(cpuset_t mask, u_int vector, pmap_t pmap,
 	uint32_t generation;
 	int cpu;
 
+#ifdef __i386__
+	sched_pin();
+#endif
+
 	/*
 	 * It is not necessary to signal other CPUs while booting or
 	 * when in the debugger.