Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Date:   Tue, 14 Apr 2020 12:31:06 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Kyung Min Park <kyung.min.park@intel.com>
Cc:     x86@kernel.org, linux-kernel@vger.kernel.org, tglx@linutronix.de,
        mingo@redhat.com, hpa@zytor.com, gregkh@linuxfoundation.org,
        ak@linux.intel.com, tony.luck@intel.com, ashok.raj@intel.com,
        ravi.v.shankar@intel.com, fenghua.yu@intel.com
Subject: Re: [PATCH v3 3/3] x86/delay: Introduce TPAUSE delay
Message-ID: <20200414103106.GK20713@hirez.programming.kicks-ass.net>
References: <1586561395-50914-1-git-send-email-kyung.min.park@intel.com>
 <1586561395-50914-4-git-send-email-kyung.min.park@intel.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <1586561395-50914-4-git-send-email-kyung.min.park@intel.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Fri, Apr 10, 2020 at 04:29:55PM -0700, Kyung Min Park wrote:
> +static inline void __tpause(u32 ecx, u32 edx, u32 eax)
> +{
> +	/* "tpause %ecx, %edx, %eax;" */
> +	asm volatile(".byte 0x66, 0x0f, 0xae, 0xf1\t\n"
> +		     :
> +		     : "c"(ecx), "d"(edx), "a"(eax));
> +}

Can we please get a comment stating from what binutils version this
opcode has a mnemonic? That way, when we raise the minimum binutils
version we can easily grep and find such things.