From: Mark Brown <broonie@kernel.org>
To: Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>,
Szabolcs Nagy <szabolcs.nagy@arm.com>,
linux-arm-kernel@lists.infradead.org,
Mark Brown <broonie@kernel.org>
Subject: [PATCH v4 0/3] arm64: Start allocating upper bits of AT_HWCAP2
Date: Wed, 6 Jul 2022 18:52:53 +0100 [thread overview]
Message-ID: <20220706175256.847703-1-broonie@kernel.org> (raw)
Currently for arm64 we expose hwcaps to userspace using the low 32 bits
of AT_HWCAP and AT_HWCAP2. Due to the ever expanding capabilties of the
architecture we have now allocated all the available bits in this scheme
so we need to expand, either using the higher bits or adding a new
AT_HWCAP3. Discussions suggest that the favoured approach for now is to
start allocating the upper bits of AT_HWCAP2.
The final patch starts allocating from the upper bits of AT_HWCAP2,
reporting the presence of FEAT_EBF16, this will conflict with my series
converting ID_AA64ISAR1_EL1 to be generated. I've got a version based on
top of that which I can send if that's convenient.
v4:
- Document status of upper bits in AT_HWCAP.
- Instead of creating AT_HWCAP3 just convert elf_hwcap to a bitmask and
start allocating the upper bits of AT_HWCAP2.
v3:
- Expand comment on CPU_FEATURES_PER_HWCAP.
v2:
- Rebase onto v5.19-rc3.
Mark Brown (3):
arm64/hwcap: Document allocation of upper bits of AT_HWCAP
arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned
long
arm64/hwcap: Support FEAT_EBF16
Documentation/arm64/elf_hwcaps.rst | 4 ++++
arch/arm64/include/asm/cpufeature.h | 2 +-
arch/arm64/include/asm/hwcap.h | 3 ++-
arch/arm64/include/uapi/asm/hwcap.h | 4 ++++
arch/arm64/kernel/cpufeature.c | 13 ++++++-------
arch/arm64/kernel/cpuinfo.c | 1 +
6 files changed, 18 insertions(+), 9 deletions(-)
base-commit: a111daf0c53ae91e71fd2bfe7497862d14132e3e
--
2.30.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2022-07-06 17:55 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-06 17:52 Mark Brown [this message]
2022-07-06 17:52 ` [PATCH v4 1/3] arm64/hwcap: Document allocation of upper bits of AT_HWCAP Mark Brown
2022-07-07 9:00 ` Szabolcs Nagy
2022-07-06 17:52 ` [PATCH v4 2/3] arm64/cpufeature: Store elf_hwcaps as a bitmap rather than unsigned long Mark Brown
2022-07-06 17:52 ` [PATCH v4 3/3] arm64/hwcap: Support FEAT_EBF16 Mark Brown
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=20220706175256.847703-1-broonie@kernel.org \
--to=broonie@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=suzuki.poulose@arm.com \
--cc=szabolcs.nagy@arm.com \
--cc=will@kernel.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.