From: "Paul E. McKenney" <paulmck@kernel.org>
To: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org
Cc: elver@google.com, akpm@linux-foundation.org, tglx@linutronix.de,
peterz@infradead.org, dianders@chromium.org, pmladek@suse.com,
torvalds@linux-foundation.org, Arnd Bergmann <arnd@arndb.de>,
"Paul E. McKenney" <paulmck@kernel.org>,
Andi Shyti <andi.shyti@linux.intel.com>,
Palmer Dabbelt <palmer@rivosinc.com>,
Masami Hiramatsu <mhiramat@kernel.org>,
linux-sh@vger.kernel.org
Subject: [PATCH cmpxchg 12/14] sh: Emulate one-byte cmpxchg
Date: Mon, 8 Apr 2024 10:49:42 -0700 [thread overview]
Message-ID: <20240408174944.907695-12-paulmck@kernel.org> (raw)
In-Reply-To: <7b3646e0-667c-48e2-8f09-e493c43c30cb@paulmck-laptop>
Use the new cmpxchg_emu_u8() to emulate one-byte cmpxchg() on sh.
[ paulmck: Drop two-byte support per Arnd Bergmann feedback. ]
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: <linux-sh@vger.kernel.org>
---
arch/sh/Kconfig | 1 +
arch/sh/include/asm/cmpxchg.h | 2 ++
2 files changed, 3 insertions(+)
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 2ad3e29f0ebec..f47e9ccf4efd2 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -16,6 +16,7 @@ config SUPERH
select ARCH_HIBERNATION_POSSIBLE if MMU
select ARCH_MIGHT_HAVE_PC_PARPORT
select ARCH_WANT_IPC_PARSE_VERSION
+ select ARCH_NEED_CMPXCHG_1_EMU
select CPU_NO_EFFICIENT_FFS
select DMA_DECLARE_COHERENT
select GENERIC_ATOMIC64
diff --git a/arch/sh/include/asm/cmpxchg.h b/arch/sh/include/asm/cmpxchg.h
index 5d617b3ef78f7..27a9040983cfe 100644
--- a/arch/sh/include/asm/cmpxchg.h
+++ b/arch/sh/include/asm/cmpxchg.h
@@ -56,6 +56,8 @@ static inline unsigned long __cmpxchg(volatile void * ptr, unsigned long old,
unsigned long new, int size)
{
switch (size) {
+ case 1:
+ return cmpxchg_emu_u8((volatile u8 *)ptr, old, new);
case 4:
return __cmpxchg_u32(ptr, old, new);
}
--
2.40.1
next parent reply other threads:[~2024-04-08 17:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <7b3646e0-667c-48e2-8f09-e493c43c30cb@paulmck-laptop>
2024-04-08 17:49 ` Paul E. McKenney [this message]
2024-04-18 8:04 ` [PATCH cmpxchg 12/14] sh: Emulate one-byte cmpxchg Geert Uytterhoeven
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=20240408174944.907695-12-paulmck@kernel.org \
--to=paulmck@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=andi.shyti@linux.intel.com \
--cc=arnd@arndb.de \
--cc=dianders@chromium.org \
--cc=elver@google.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-sh@vger.kernel.org \
--cc=mhiramat@kernel.org \
--cc=palmer@rivosinc.com \
--cc=peterz@infradead.org \
--cc=pmladek@suse.com \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.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 read-only IMAP folder(s) and NNTP newsgroup(s).