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AKwUvBxi6X02mHmkXsZDsNxVnVkltfEDd01tlq3wH+gbm9JrJj0LsqlhFDPheIxprPb0jI0XR/U92KZ/nPuzbS8=@vger.kernel.org X-Gm-Message-State: AFuF++mqYvC64inS6Pw1qopJC8BwmG7Jd5wRbx9Y0Vm9NKR0kj/JG32O UvtRFBrBzHcziyii0vdxPT2PDHH5AB8fqJ7bUOtzE0Xx64x0c8JLNIWjph9AlVUGxhQTWS4dEzI ynpojQNnWkwgKto9zmyxAV+4/URJBYfFyYA== X-Gm-Gg: AYBFou1Z81t0Tg+ieggdE5tg6PLWCRUxb9nRjdP1KLDnkvbQpMVj5ga6+s3ogOju8lf L+ugIf49kcMgGSCrTFqXJfU37Xciv8CTQgqs7GWOtt8YPIApz5cloesGhaPwWz58qRO+gMwTOsl 6AShRt0jtZAhlUXP2Qnb9XPl+p1sQBgPNPJExr2HqTnpug6TjkxeaMjBz4rPThJz6xdG55vidIw RvBBYT6Fw3bd1WXzto3oYBznhD0YNUlXHPn3ydIeTp8rUzq23gln2kqSelx9H6u8GZvN9OdlaYj 3d6tyA6B+8k0Kw3WBTlZ5BI1BMeVhSVg08b0jBcy8Qq6+an432ZssNts/fZ90wtf1NkyhxHwri5 ZalXE8HoISo9/5IX4tLMDvdNzZE4BJpAqQnE7pHD47UrU7bnmPlvqPO1G5MMz1EsnzBR1yEwjP8 tSC6VGwlu4 X-Received: by 2002:a05:620a:2b49:b0:939:10dd:9c01 with SMTP id af79cd13be357-93bb78ecc33mr880261085a.38.1789608740708; Wed, 16 Sep 2026 18:32:20 -0700 (PDT) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 References: <20260916200215.21774-1-brads@mainlining.org> <20260916200215.21774-6-brads@mainlining.org> In-Reply-To: <20260916200215.21774-6-brads@mainlining.org> From: Max Filippov Date: Wed, 16 Sep 2026 18:32:08 -0700 X-Gm-Features: AcwNN1WCG_JOJrf2Xbrmh8jFY2fRzqOy5q6E4Cc5_T2BPoTD4KB-hY5Oy_mqGNs Message-ID: Subject: Re: [PATCH v2 5/5] xtensa: Emulate two-byte cmpxchg To: Bradley Morgan Cc: Andrew Morton , Vineet Gupta , Guo Ren , Yoshinori Sato , Rich Felker , Chris Zankel , Arnd Bergmann , "Paul E . McKenney" , David Laight , John Paul Adrian Glaubitz , linux-snps-arc@lists.infradead.org, linux-csky@vger.kernel.org, linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, Sep 16, 2026 at 1:02=E2=80=AFPM Bradley Morgan wrote: > > Xtensa has no two-byte atomic compare and swap, so the __cmpxchg() > switch lets case 2 fall through to __cmpxchg_called_with_bad_pointer(), > which is declared but never defined, so a two-byte cmpxchg() fails at > link time. Route case 2 through the new cmpxchg_emu_u16(), which takes > natural u16 arguments, so the unsigned long old and new narrow at the > function boundary. > > Signed-off-by: Bradley Morgan > --- > arch/xtensa/include/asm/cmpxchg.h | 1 + > 1 file changed, 1 insertion(+) Reviewed-by: Max Filippov --=20 Thanks. -- Max