From owner-freebsd-alpha Tue Jan 2 12: 6:59 2001 From owner-freebsd-alpha@FreeBSD.ORG Tue Jan 2 12:06:54 2001 Return-Path: Delivered-To: freebsd-alpha@freebsd.org Received: from meow.osd.bsdi.com (meow.osd.bsdi.com [204.216.28.88]) by hub.freebsd.org (Postfix) with ESMTP id 65E7537B404 for ; Tue, 2 Jan 2001 12:06:48 -0800 (PST) Received: from laptop.baldwin.cx (john@jhb-laptop.osd.bsdi.com [204.216.28.241]) by meow.osd.bsdi.com (8.11.1/8.9.3) with ESMTP id f02K6VG01723 for ; Tue, 2 Jan 2001 12:06:31 -0800 (PST) (envelope-from john@baldwin.cx) Resent-Message-Id: <200101022006.f02K6VG01723@meow.osd.bsdi.com> Message-ID: X-Mailer: XFMail 1.4.0 on FreeBSD X-Priority: 3 (Normal) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8bit MIME-Version: 1.0 Resent-Date: Fri, 17 Nov 2000 10:51:31 -0800 (PST) Resent-From: John Baldwin Resent-To: Andrew Gallatin Date: Tue, 02 Jan 2001 12:06:56 -0800 (PST) From: John Baldwin To: alpha@FreeBSD.org Subject: Disabling ints via IPL Resent-Sender: john@baldwin.cx Sender: owner-freebsd-alpha@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Part III... -----FW: Re: PC164 IDE only works (was: SMPng stability)----- Date: Fri, 17 Nov 2000 10:51:31 -0800 (PST) From: John Baldwin To: Andrew Gallatin Subject: Re: PC164 IDE only works (was: SMPng stability) Cc: mjacob@feral.com On 17-Nov-00 Andrew Gallatin wrote: > > Next question -- how the heck do we keep the ipl at ALPHA_PSL_IPL_IO > until the interrupt thread is run? Can you muck with the psl in the > in hardware frame and have the palcode beleive you? > > Keeping the ipl at 4 will also mean mucking with exception return, > etc, etc, etc. Ick. Well, first of all, we should only do this for PC164's as this is going to kill interrupt performance. :( You can muck with the IPL in the saved psr on the stack. You will only need to do this for DEVICE_IO interrupts. And you can do it by writing the current IPL into the saved frame from within interrupt(). IOW, in the DEVICE_IO case block, have something like: if (user_has_a_lame_pc164) { frame.psr &= ~ALPHA_PSR_IPL_MASK; frame.psr |= alpha_read_psr() & ALPHA_PSR_IPL_MASK; } Then in ithd_loop(), before grabbing sched_lock via mtx_enter(), add in: if (user_has_a_lame_pc164) alpha_pal_swpipl(ALPHA_PSL_IPL_0); That should do the trick. > Drew -- John Baldwin -- http://www.FreeBSD.org/~jhb/ PGP Key: http://www.baldwin.cx/~john/pgpkey.asc "Power Users Use the Power to Serve!" - http://www.FreeBSD.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-alpha" in the body of the message