Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261222AbTENUa3 (ORCPT ); Wed, 14 May 2003 16:30:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261225AbTENUa3 (ORCPT ); Wed, 14 May 2003 16:30:29 -0400 Received: from fmr02.intel.com ([192.55.52.25]:63983 "EHLO caduceus.fm.intel.com") by vger.kernel.org with ESMTP id S261222AbTENUa2 convert rfc822-to-8bit (ORCPT ); Wed, 14 May 2003 16:30:28 -0400 content-class: urn:content-classes:message MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7BIT X-MimeOLE: Produced By Microsoft Exchange V6.0.6375.0 Subject: RE: RFC Proposal to enable MSI support in Linux kernel Date: Wed, 14 May 2003 13:43:15 -0700 Message-ID: <3014AAAC8E0930438FD38EBF6DCEB56401E451DE@fmsmsx407.fm.intel.com> X-MS-Has-Attach: X-MS-TNEF-Correlator: Thread-Topic: RFC Proposal to enable MSI support in Linux kernel Thread-Index: AcMaU+U543/3MAAzSeqap8RlnFTsuwAAzqhw From: "Nakajima, Jun" To: "Zwane Mwaikambo" Cc: "Nguyen, Tom L" , , "Saxena, Sunil" , "Mallick, Asit K" , "Carbonari, Steven" X-OriginalArrivalTime: 14 May 2003 20:43:15.0486 (UTC) FILETIME=[717BDBE0:01C31A59] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1803 Lines: 39 ISA devices typically use hard-coded IRQs (< 16), and the drivers for those also assume such IRQs. You can break the driver if you provide the vector number instead of the IRQ for them. Unfortunately, vectors <16 are used for the processor, and thus not available. Good news is that vectors assigned to I/O are equal to or higher than FIRST_DEVICE_VECTOR (> 16), so there are no conflicts between the IRQ and vector space, i.e. you don't need to check if it's vector or IRQ at do_IRQ() time, for example. Non legacy drivers are all drivers but such legacy drivers. Included are PCI, USB drivers, etc. Thanks, Jun > -----Original Message----- > From: Zwane Mwaikambo [mailto:zwane@linuxpower.ca] > Sent: Wednesday, May 14, 2003 12:54 PM > To: Nakajima, Jun > Cc: Nguyen, Tom L; linux-kernel@vger.kernel.org; Saxena, Sunil; Mallick, > Asit K; Carbonari, Steven > Subject: RE: RFC Proposal to enable MSI support in Linux kernel > > On Wed, 14 May 2003, Nakajima, Jun wrote: > > > That's a good idea, and that's the way we did this (we added MSI > > support on top of the vector-based indexing). If people are interested > in > > the vector-based indexing (i.e. provide the vector number to device > > drivers (non-legacy drivers only) instead of IRQ) for some other uses, > we > > would like to discuss possible cleaner implementations. > > > > Long will post a patch containing the vector-based indexing part only. > > Thanks! It'd be a lot easier to test the core changes too. What do you > mean by non legacy? > > Zwane > -- > function.linuxpower.ca - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/