Date: Sat, 13 Jul 2019 16:32:19 +0000 (UTC) From: Alan Cox <alc@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r349975 - head/sys/arm64/arm64 Message-ID: <201907131632.x6DGWJqZ084049@repo.freebsd.org>
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Author: alc Date: Sat Jul 13 16:32:19 2019 New Revision: 349975 URL: https://svnweb.freebsd.org/changeset/base/349975 Log: Revert r349442, which was a workaround for bus errors caused by an errant TLB entry. Specifically, at the start of pmap_enter_quick_locked(), we would sometimes have a TLB entry for an invalid PTE, and we would need to issue a TLB invalidation before exiting pmap_enter_quick_locked(). However, we should never have a TLB entry for an invalid PTE. r349905 has addressed the root cause of the problem, and so we no longer need this workaround. X-MFC after: r349905 Modified: head/sys/arm64/arm64/pmap.c Modified: head/sys/arm64/arm64/pmap.c ============================================================================== --- head/sys/arm64/arm64/pmap.c Sat Jul 13 16:07:38 2019 (r349974) +++ head/sys/arm64/arm64/pmap.c Sat Jul 13 16:32:19 2019 (r349975) @@ -3713,14 +3713,7 @@ pmap_enter_quick_locked(pmap_t pmap, vm_offset_t va, v cpu_icache_sync_range(PHYS_TO_DMAP(pa), PAGE_SIZE); pmap_load_store(l3, l3_val); - - /* - * XXX In principle, because this L3 entry was invalid, we should not - * need to perform a TLB invalidation here. However, in practice, - * when simply performing a "dsb ishst" here, processes are being - * terminated due to bus errors and segmentation violations. - */ - pmap_invalidate_page(pmap, va); + dsb(ishst); return (mpte); }
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