From: Conor Dooley <conor@kernel.org>
To: "Clément Léger" <cleger@rivosinc.com>
Cc: "Paul Walmsley" <paul.walmsley@sifive.com>,
"Palmer Dabbelt" <palmer@dabbelt.com>,
"Albert Ou" <aou@eecs.berkeley.edu>,
"Atish Patra" <atishp@rivosinc.com>,
"Andrew Jones" <ajones@ventanamicro.com>,
"Evan Green" <evan@rivosinc.com>,
"Björn Topel" <bjorn@rivosinc.com>,
linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
"Ron Minnich" <rminnich@gmail.com>,
"Daniel Maslowski" <cyrevolt@googlemail.com>
Subject: Re: [PATCH 0/7] Add support to handle misaligned accesses in S-mode
Date: Sat, 30 Sep 2023 10:23:58 +0100 [thread overview]
Message-ID: <20230930-patchy-curdle-ef5ee6e1a17c@spud> (raw)
In-Reply-To: <20230926150316.1129648-1-cleger@rivosinc.com>
[-- Attachment #1.1: Type: text/plain, Size: 1740 bytes --]
On Tue, Sep 26, 2023 at 05:03:09PM +0200, Clément Léger wrote:
> Since commit 61cadb9 ("Provide new description of misaligned load/store
> behavior compatible with privileged architecture.") in the RISC-V ISA
> manual, it is stated that misaligned load/store might not be supported.
> However, the RISC-V kernel uABI describes that misaligned accesses are
> supported. In order to support that, this series adds support for S-mode
> handling of misaligned accesses as well support for prctl(PR_UNALIGN).
>
> Handling misaligned access in kernel allows for a finer grain control
> of the misaligned accesses behavior, and thanks to the prctl call, can
> allow disabling misaligned access emulation to generate SIGBUS. User
> space can then optimize its software by removing such access based on
> SIGBUS generation.
>
> Currently, this series is useful for people that uses a SBI that does
> not handled misaligned traps. In a near future, this series will make
> use a SBI extension [1] allowing to request delegation of the
> misaligned load/store traps to the S-mode software. This extension has
> been submitted for review to the riscv tech-prs group. An OpenSBI
> implementation for this spec is available at [2].
>
> This series can be tested using the spike simulator [3] and an openSBI
> version [4] which allows to always delegate misaligned load/store to
> S-mode.
Some patches in this series do not build for any configs, some are
broken for clang builds and others are broken for nommu. Please try to
build test this more thoroughly before you submit the next version.
Also, AIUI, this series should be marked RFC since the SBI extension
this relies on has not been frozen.
Cheers,
Conor.
[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 228 bytes --]
[-- Attachment #2: Type: text/plain, Size: 161 bytes --]
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2023-09-30 9:24 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-26 15:03 [PATCH 0/7] Add support to handle misaligned accesses in S-mode Clément Léger
2023-09-26 15:03 ` [PATCH 1/7] riscv: remove unused functions in traps_misaligned.c Clément Léger
2023-09-26 15:03 ` [PATCH 2/7] riscv: add support for misaligned handling in S-mode Clément Léger
2023-09-26 15:03 ` [PATCH 3/7] riscv: report perf event for misaligned fault Clément Léger
2023-09-26 15:03 ` [PATCH 4/7] riscv: add floating point insn support to misaligned access emulation Clément Léger
2023-09-26 15:03 ` [PATCH 5/7] riscv: add support for sysctl unaligned_enabled control Clément Léger
2023-09-26 15:03 ` [PATCH 6/7] riscv: report misaligned accesses emulation to hwprobe Clément Léger
2023-09-26 21:57 ` Evan Green
2023-09-28 7:46 ` Clément Léger
2023-09-28 16:51 ` Evan Green
2023-10-03 9:50 ` Atish Kumar Patra
2023-09-29 1:02 ` kernel test robot
2023-09-26 15:03 ` [PATCH 7/7] riscv: add support for PR_SET_UNALIGN and PR_GET_UNALIGN Clément Léger
2023-09-26 21:43 ` [PATCH 0/7] Add support to handle misaligned accesses in S-mode Evan Green
2023-09-28 7:49 ` Clément Léger
2023-09-28 16:48 ` Evan Green
2023-10-03 8:40 ` Atish Kumar Patra
2023-10-03 15:39 ` ron minnich
2023-09-30 9:23 ` Conor Dooley [this message]
2023-10-02 7:40 ` Clément Léger
2023-10-02 10:49 ` Conor Dooley
2023-10-02 11:18 ` Clément Léger
2023-10-02 15:32 ` ron minnich
2023-10-02 22:22 ` Jessica Clarke
2023-10-03 15:37 ` ron minnich
2023-10-03 8:12 ` Clément Léger
2023-10-04 8:26 ` David Laight
2023-10-04 10:03 ` Clément Léger
2023-10-04 14:10 ` David Laight
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=20230930-patchy-curdle-ef5ee6e1a17c@spud \
--to=conor@kernel.org \
--cc=ajones@ventanamicro.com \
--cc=aou@eecs.berkeley.edu \
--cc=atishp@rivosinc.com \
--cc=bjorn@rivosinc.com \
--cc=cleger@rivosinc.com \
--cc=cyrevolt@googlemail.com \
--cc=evan@rivosinc.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=palmer@dabbelt.com \
--cc=paul.walmsley@sifive.com \
--cc=rminnich@gmail.com \
/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