From: will.deacon@arm.com (Will Deacon)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH v2 3/9] arm64: mm: Permit transitioning from Global to Non-Global without BBM
Date: Mon, 29 Jan 2018 11:59:54 +0000 [thread overview]
Message-ID: <1517227200-20412-4-git-send-email-will.deacon@arm.com> (raw)
In-Reply-To: <1517227200-20412-1-git-send-email-will.deacon@arm.com>
Break-before-make is not needed when transitioning from Global to
Non-Global mappings, provided that the contiguous hint is not being used.
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
arch/arm64/mm/mmu.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index b44992ec9643..fc7902bda02b 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -118,6 +118,10 @@ static bool pgattr_change_is_safe(u64 old, u64 new)
if ((old | new) & PTE_CONT)
return false;
+ /* Transitioning from Global to Non-Global is safe */
+ if (((old ^ new) == PTE_NG) && (new & PTE_NG))
+ return true;
+
return ((old ^ new) & ~mask) == 0;
}
--
2.1.4
next prev parent reply other threads:[~2018-01-29 11:59 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-29 11:59 [PATCH v2 0/9] Fix kpti-enabled kernels for Cavium ThunderX Will Deacon
2018-01-29 11:59 ` [PATCH v2 1/9] arm64: Add software workaround for Falkor erratum 1041 Will Deacon
2018-01-29 11:59 ` [PATCH v2 2/9] arm64: kpti: Make use of nG dependent on arm64_kernel_unmapped_at_el0() Will Deacon
2018-01-29 11:59 ` Will Deacon [this message]
2018-01-29 11:59 ` [PATCH v2 4/9] arm64: kpti: Add ->enable callback to remap swapper using nG mappings Will Deacon
2018-01-30 10:30 ` Will Deacon
2018-01-29 11:59 ` [PATCH v2 5/9] arm64: Force KPTI to be disabled on Cavium ThunderX Will Deacon
2018-01-29 11:59 ` [PATCH v2 6/9] arm64: assembler: Change order of macro arguments in phys_to_ttbr Will Deacon
2018-01-29 11:59 ` [PATCH v2 7/9] arm64: entry: Reword comment about post_ttbr_update_workaround Will Deacon
2018-02-03 11:15 ` Ard Biesheuvel
2018-02-05 16:41 ` Will Deacon
2018-01-29 11:59 ` [PATCH v2 8/9] arm64: assembler: Align phys_to_pte with pte_to_phys Will Deacon
2018-01-29 12:00 ` [PATCH v2 9/9] arm64: idmap: Use "awx" flags for .idmap.text .pushsection directives Will Deacon
2018-02-03 11:36 ` [PATCH v2 0/9] Fix kpti-enabled kernels for Cavium ThunderX Ard Biesheuvel
2018-02-05 16:41 ` Will Deacon
2018-02-05 19:21 ` Ard Biesheuvel
2018-02-06 22:31 ` Catalin Marinas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1517227200-20412-4-git-send-email-will.deacon@arm.com \
--to=will.deacon@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).