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[103.168.172.201]) by smtp.gmail.com with ESMTPSA id af79cd13be357-8c37f4a7962sm1243709185a.11.2026.01.11.04.02.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 11 Jan 2026 04:02:41 -0800 (PST) Received: from phl-compute-01.internal (phl-compute-01.internal [10.202.2.41]) by mailfauth.phl.internal (Postfix) with ESMTP id D0986F40068; Sun, 11 Jan 2026 07:02:40 -0500 (EST) Received: from phl-frontend-03 ([10.202.2.162]) by phl-compute-01.internal (MEProxy); Sun, 11 Jan 2026 07:02:40 -0500 X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeefgedrtddtgdduudeghedvucetufdoteggodetrf dotffvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfurfetoffkrfgpnffqhgenuceu rghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmnecujf gurhephffvvefufffkofgjfhgggfestdekredtredttdenucfhrhhomhepuehoqhhunhcu hfgvnhhguceosghoqhhunhdrfhgvnhhgsehgmhgrihhlrdgtohhmqeenucggtffrrghtth gvrhhnpedvveekvddtffelffelfedvudefffeuheejgeeivedufffgledvgeduveffueeh leenucffohhmrghinhepmhhsghhiugdrlhhinhhknecuvehluhhsthgvrhfuihiivgeptd enucfrrghrrghmpehmrghilhhfrhhomhepsghoqhhunhdomhgvshhmthhprghuthhhphgv rhhsohhnrghlihhthidqieelvdeghedtieegqddujeejkeehheehvddqsghoqhhunhdrfh gvnhhgpeepghhmrghilhdrtghomhesfhhigihmvgdrnhgrmhgvpdhnsggprhgtphhtthho peduhedpmhhouggvpehsmhhtphhouhhtpdhrtghpthhtohepphgvthgvrhiisehinhhfrh gruggvrggurdhorhhgpdhrtghpthhtohepmhhinhhgoheskhgvrhhnvghlrdhorhhgpdhr tghpthhtoheprhhushhtqdhfohhrqdhlihhnuhigsehvghgvrhdrkhgvrhhnvghlrdhorh hgpdhrtghpthhtoheplhhinhhugidqkhgvrhhnvghlsehvghgvrhdrkhgvrhhnvghlrdho rhhgpdhrtghpthhtohepfihilhhlsehkvghrnhgvlhdrohhrghdprhgtphhtthhopehmrg hrkhdrrhhuthhlrghnugesrghrmhdrtghomhdprhgtphhtthhopehtghhlgieslhhinhhu thhrohhnihigrdguvgdprhgtphhtthhopehojhgvuggrsehkvghrnhgvlhdrohhrghdprh gtphhtthhopehgrghrhiesghgrrhihghhuohdrnhgvth X-ME-Proxy: Feedback-ID: iad51458e:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Sun, 11 Jan 2026 07:02:40 -0500 (EST) From: Boqun Feng To: "Peter Zijlstra" , "Ingo Molnar" Cc: rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org, "Will Deacon" , "Mark Rutland" , "Thomas Gleixner" , "Miguel Ojeda" , "Gary Guo" , "Alice Ryhl" , "Andreas Hindborg" , "Benno Lossin" , "Danilo Krummrich" , FUJITA Tomonori , Boqun Feng Subject: [PATCH 11/36] rust: helpers: Add i8/i16 atomic try_cmpxchg helpers Date: Sun, 11 Jan 2026 20:01:44 +0800 Message-ID: <20260111120209.6133-9-boqun.feng@gmail.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260111120209.6133-1-boqun.feng@gmail.com> References: <20260111115808.5702-1-boqun.feng@gmail.com> <20260111120209.6133-1-boqun.feng@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: FUJITA Tomonori Add i8/i16 atomic try_cmpxchg helpers that call try_cmpxchg() macro implementing atomic try_cmpxchg using architecture-specific instructions. [boqun: Add comments explaining CONFIG_ARCH_SUPPORTS_ATOMIC_RMW and use try_cmpxchg() instead of raw_try_cmpxchg()] Signed-off-by: FUJITA Tomonori Signed-off-by: Boqun Feng Link: https://patch.msgid.link/20251227115951.1424458-2-fujita.tomonori@gmail.com --- rust/helpers/atomic_ext.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/rust/helpers/atomic_ext.c b/rust/helpers/atomic_ext.c index 76e392c39c7b..5ee127f1cc80 100644 --- a/rust/helpers/atomic_ext.c +++ b/rust/helpers/atomic_ext.c @@ -90,3 +90,20 @@ __rust_helper s16 rust_helper_atomic_i16_xchg_relaxed(s16 *ptr, s16 new) { return xchg_relaxed(ptr, new); } + +/* + * try_cmpxchg helpers depend on ARCH_SUPPORTS_ATOMIC_RMW and on the + * architecture provding try_cmpxchg() support for i8 and i16. + * + * The architectures that currently support Rust (x86_64, armv7, + * arm64, riscv, and loongarch) satisfy these requirements. + */ +__rust_helper bool rust_helper_atomic_i8_try_cmpxchg(s8 *ptr, s8 *old, s8 new) +{ + return try_cmpxchg(ptr, old, new); +} + +__rust_helper bool rust_helper_atomic_i16_try_cmpxchg(s16 *ptr, s16 *old, s16 new) +{ + return try_cmpxchg(ptr, old, new); +} -- 2.51.0