Date: Mon, 8 Aug 2022 03:22:08 GMT From: Doug Moore <dougm@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-branches@FreeBSD.org Subject: git: b7bd54e4ec5b - stable/13 - x86/iommu: Shrink the critical section in dmar_qi_task() Message-ID: <202208080322.2783M8t9017750@gitrepo.freebsd.org>
next in thread | raw e-mail | index | archive | help
The branch stable/13 has been updated by dougm: URL: https://cgit.FreeBSD.org/src/commit/?id=b7bd54e4ec5b5f59c1651e3600dbc808ddefa316 commit b7bd54e4ec5b5f59c1651e3600dbc808ddefa316 Author: Alan Cox <alc@FreeBSD.org> AuthorDate: 2022-07-18 00:56:39 +0000 Commit: Doug Moore <dougm@FreeBSD.org> CommitDate: 2022-08-08 03:19:02 +0000 x86/iommu: Shrink the critical section in dmar_qi_task() It is safe to test and clear the Invalidation Wait Descriptor Complete flag before acquiring the DMAR lock in dmar_qi_task(), rather than waiting until the lock is held. Reviewed by: kib MFC after: 2 weeks (cherry picked from commit 4eaaacc75535befdb9894cca4e0d8da376328fa4) --- sys/x86/iommu/intel_qi.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/sys/x86/iommu/intel_qi.c b/sys/x86/iommu/intel_qi.c index 1400be3852e9..174cf9ea19a8 100644 --- a/sys/x86/iommu/intel_qi.c +++ b/sys/x86/iommu/intel_qi.c @@ -354,6 +354,16 @@ dmar_qi_task(void *arg, int pending __unused) unit = arg; + /* + * Request an interrupt on the completion of the next invalidation + * wait descriptor with the IF field set. + */ + ics = dmar_read4(unit, DMAR_ICS_REG); + if ((ics & DMAR_ICS_IWC) != 0) { + ics = DMAR_ICS_IWC; + dmar_write4(unit, DMAR_ICS_REG, ics); + } + DMAR_LOCK(unit); for (;;) { entry = TAILQ_FIRST(&unit->tlb_flush_entries); @@ -366,11 +376,6 @@ dmar_qi_task(void *arg, int pending __unused) dmar_domain_free_entry(entry, true); DMAR_LOCK(unit); } - ics = dmar_read4(unit, DMAR_ICS_REG); - if ((ics & DMAR_ICS_IWC) != 0) { - ics = DMAR_ICS_IWC; - dmar_write4(unit, DMAR_ICS_REG, ics); - } if (unit->inv_seq_waiters > 0) wakeup(&unit->inv_seq_waiters); DMAR_UNLOCK(unit);
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?202208080322.2783M8t9017750>