From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: [PATCH v4 22/27] compiler: Simple READ/WRITE_ONCE() implementations Date: Fri, 21 Feb 2020 14:34:38 +0100 Message-ID: <20200221134216.573806438@infradead.org> References: <20200221133416.777099322@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Return-path: Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, rostedt@goodmis.org Cc: peterz@infradead.org, mingo@kernel.org, joel@joelfernandes.org, gregkh@linuxfoundation.org, gustavo@embeddedor.com, tglx@linutronix.de, paulmck@kernel.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, luto@kernel.org, tony.luck@intel.com, frederic@kernel.org, dan.carpenter@oracle.com, mhiramat@kernel.org List-Id: linux-arch.vger.kernel.org Because I need WRITE_ONCE_NOCHECK() and in anticipation of Will's READ_ONCE rewrite, provide __{READ,WRITE}_ONCE_SCALAR(). Signed-off-by: Peter Zijlstra (Intel) --- include/linux/compiler.h | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -289,6 +289,14 @@ unsigned long read_word_at_a_time(const __u.__val; \ }) +#define __READ_ONCE_SCALAR(x) \ + (*(const volatile typeof(x) *)&(x)) + +#define __WRITE_ONCE_SCALAR(x, val) \ +do { \ + *(volatile typeof(x) *)&(x) = val; \ +} while (0) + #endif /* __KERNEL__ */ /* From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org ([198.137.202.133]:56318 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728639AbgBUNu1 (ORCPT ); Fri, 21 Feb 2020 08:50:27 -0500 Message-ID: <20200221134216.573806438@infradead.org> Date: Fri, 21 Feb 2020 14:34:38 +0100 From: Peter Zijlstra Subject: [PATCH v4 22/27] compiler: Simple READ/WRITE_ONCE() implementations References: <20200221133416.777099322@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-arch-owner@vger.kernel.org List-ID: To: linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, rostedt@goodmis.org Cc: peterz@infradead.org, mingo@kernel.org, joel@joelfernandes.org, gregkh@linuxfoundation.org, gustavo@embeddedor.com, tglx@linutronix.de, paulmck@kernel.org, josh@joshtriplett.org, mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com, luto@kernel.org, tony.luck@intel.com, frederic@kernel.org, dan.carpenter@oracle.com, mhiramat@kernel.org Message-ID: <20200221133438.lv2dgU3e3IyAZY25LWGQZAvtWkW0vzi0_xURc6j9Qeg@z> Because I need WRITE_ONCE_NOCHECK() and in anticipation of Will's READ_ONCE rewrite, provide __{READ,WRITE}_ONCE_SCALAR(). Signed-off-by: Peter Zijlstra (Intel) --- include/linux/compiler.h | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -289,6 +289,14 @@ unsigned long read_word_at_a_time(const __u.__val; \ }) +#define __READ_ONCE_SCALAR(x) \ + (*(const volatile typeof(x) *)&(x)) + +#define __WRITE_ONCE_SCALAR(x, val) \ +do { \ + *(volatile typeof(x) *)&(x) = val; \ +} while (0) + #endif /* __KERNEL__ */ /*