From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sj-iport-4.cisco.com (sj-iport-4.cisco.com [171.68.10.86]) by ozlabs.org (Postfix) with ESMTP id 23310DDE34 for ; Wed, 4 Apr 2007 14:07:15 +1000 (EST) To: Benjamin Herrenschmidt Subject: Re: [PATCH] Allow drivers to map individual 4k pages to userspace References: <17938.14674.621036.256587@cargo.ozlabs.ibm.com> <1175657025.30879.45.camel@localhost.localdomain> From: Roland Dreier Date: Tue, 03 Apr 2007 21:07:12 -0700 In-Reply-To: <1175657025.30879.45.camel@localhost.localdomain> (Benjamin Herrenschmidt's message of "Wed, 04 Apr 2007 13:23:45 +1000") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linuxppc-dev@ozlabs.org, Joachim Fenkes , Paul Mackerras List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , > It's somewhat architected. I doubt there will ever be a processor that > can have an eHCA and doesn't support that trick. The thing is, eHCA is > platform specific, so the remap_4k_pfn would have to be called by driver > specific code, but that's not a problem since that driver will only ever > be used on those platforms that support that call. If I'm going off on something irrelevant, just tell me. But is there a chance that you would want to build a kernel that can boot on both a platform that has eHCA, and also on some other platform that cannot support remap_4k_pfn? If so does this approach cause problems? - R.