mail archive of the barebox mailing list
 help / color / mirror / Atom feed
From: Ahmad Fatoum <a.fatoum@pengutronix.de>
To: barebox@lists.infradead.org
Subject: [PATCH 0/4] ARM: mmu: ensure PTE is written at once
Date: Wed, 21 May 2025 19:41:00 +0200	[thread overview]
Message-ID: <20250521174104.1570239-1-a.fatoum@pengutronix.de> (raw)

Writing the PTE with a normal non-volatile access is a bad idea, because
speculation may already use a partially written entry.

Use WRITE_ONCE to turn this into a volatile write via a new set_pte
helper. The extra helper is useful for type enforcement and for future
extension when we start to consistently apply break-before-make[1].

Ahmad Fatoum (4):
  arch: sync READ_ONCE/WRITE_ONCE with Linux
  ARM64: mmu: document granule size calculation
  ARM: mmu: ensure PTE is written at once
  WIP: break before make and don't invalidate uncached regions being
    remapped

 Documentation/devel/porting.rst     |   2 +
 arch/arm/cpu/mmu_32.c               | 247 +++++++++++++++++++++++-----
 arch/arm/cpu/mmu_64.c               |  38 ++++-
 arch/arm/include/asm/barrier.h      |   8 +
 arch/kvx/include/asm/barrier.h      |   2 +
 arch/mips/include/asm/barrier.h     |   8 +
 arch/openrisc/include/asm/barrier.h |   8 +
 arch/powerpc/include/asm/barrier.h  |   8 +
 arch/sandbox/include/asm/barrier.h  |   8 +
 arch/x86/include/asm/barrier.h      |   8 +
 include/asm-generic/barrier.h       |  24 +++
 include/asm-generic/rwonce.h        |  87 ++++++++++
 include/linux/bitops.h              |   2 +-
 include/linux/compiler.h            |  94 -----------
 include/linux/compiler_types.h      |  46 ++++++
 include/linux/list.h                |   1 +
 16 files changed, 449 insertions(+), 142 deletions(-)
 create mode 100644 arch/arm/include/asm/barrier.h
 create mode 100644 arch/mips/include/asm/barrier.h
 create mode 100644 arch/openrisc/include/asm/barrier.h
 create mode 100644 arch/powerpc/include/asm/barrier.h
 create mode 100644 arch/sandbox/include/asm/barrier.h
 create mode 100644 arch/x86/include/asm/barrier.h
 create mode 100644 include/asm-generic/barrier.h
 create mode 100644 include/asm-generic/rwonce.h

-- 
2.39.5




             reply	other threads:[~2025-05-21 17:42 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-05-21 17:41 Ahmad Fatoum [this message]
2025-05-21 17:41 ` [PATCH 1/4] arch: sync READ_ONCE/WRITE_ONCE with Linux Ahmad Fatoum
2025-05-21 17:41 ` [PATCH 2/4] ARM64: mmu: document granule size calculation Ahmad Fatoum
2025-05-21 17:41 ` [PATCH 3/4] ARM: mmu: ensure PTE is written at once Ahmad Fatoum
2025-05-21 17:41 ` [PATCH 4/4] WIP: break before make and don't invalidate uncached regions being remapped Ahmad Fatoum
2025-05-26 13:51 ` (subset) [PATCH 0/4] ARM: mmu: ensure PTE is written at once Sascha Hauer

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=20250521174104.1570239-1-a.fatoum@pengutronix.de \
    --to=a.fatoum@pengutronix.de \
    --cc=barebox@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