From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Mon, 28 Jan 2008 21:29:17 +0000 (GMT) Received: from bsdimp.com ([199.45.160.85]:57821 "EHLO harmony.bsdimp.com") by ftp.linux-mips.org with ESMTP id S28584682AbYA1V3H (ORCPT ); Mon, 28 Jan 2008 21:29:07 +0000 Received: from localhost (localhost [127.0.0.1]) by harmony.bsdimp.com (8.14.2/8.14.1) with ESMTP id m0SLPsYb043578; Mon, 28 Jan 2008 14:25:54 -0700 (MST) (envelope-from imp@bsdimp.com) Date: Mon, 28 Jan 2008 14:26:10 -0700 (MST) Message-Id: <20080128.142610.1159133450.imp@bsdimp.com> To: ralf@linux-mips.org Cc: cfriesen@nortel.com, linux-mips@linux-mips.org Subject: Re: quick question on 64-bit values with 32-bit inline assembly From: "M. Warner Losh" In-Reply-To: <20080128211803.GA20434@linux-mips.org> References: <20080122200751.GA2672@linux-mips.org> <20080128.140245.-108809632.imp@bsdimp.com> <20080128211803.GA20434@linux-mips.org> X-Mailer: Mew version 5.2 on Emacs 21.3 / Mule 5.0 (SAKAKI) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 18157 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: imp@bsdimp.com Precedence: bulk X-list: linux-mips In message: <20080128211803.GA20434@linux-mips.org> Ralf Baechle writes: : On Mon, Jan 28, 2008 at 02:02:45PM -0700, M. Warner Losh wrote: : : > : this specific interaction of ABI and processor architecture then it was : > : probably found not to implement such a special read because it is messy : > : in more than one way. : > : > When 64-bit operations are enabled, you get all 64-bits. When they : > aren't, only the lower 32-bits of the counter are provided (with sign : > extension). So when operating in 32-bit mode, saving the upper 32 : > bits are not necessary (or even possible). : : The architecture manual doesn't make a difference between 32-bit and : 64-bit for rdhwr. My reading is the entire 64-bit would have to be : transfered. Hmmm, the manual I have specifically calls out the difference... Has cavium provided a public version? Warner