From owner-freebsd-mips@FreeBSD.ORG Tue Jun 8 06:13:55 2010 Return-Path: Delivered-To: mips@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 4794F106566C; Tue, 8 Jun 2010 06:13:55 +0000 (UTC) (envelope-from c.jayachandran@gmail.com) Received: from mail-vw0-f54.google.com (mail-vw0-f54.google.com [209.85.212.54]) by mx1.freebsd.org (Postfix) with ESMTP id D0CDD8FC08; Tue, 8 Jun 2010 06:13:54 +0000 (UTC) Received: by vws4 with SMTP id 4so3215745vws.13 for ; Mon, 07 Jun 2010 23:13:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:received:in-reply-to :references:date:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=okgM1HjDBHjO/A/xm+Wz9eyCrejOr8muCUP6OhZoHYw=; b=SnA8Fd24FkBbKXMO+Rmh4Qtdq11U5UWMeHF/ssG46k4n+KvvRcVz4x9zxzmdbNmZON VElevgsHM0eRJ+61kTc1UYbvPRdo5qbwKW0JAj4BaZRmgh5SIOgeTn98kN3NPPTWQL5X t1WFhx0ZHm0C5/46Pi6kQ/wtDHtiGMAmd+xVs= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; b=rVpQWPW3Ceeiv/yzwYCfZfNX21WECjcJUfTFo+Yd/MyjpMZMp5Hitzjb3UkvdD9j4a dG+g3rGlSk2W1PfifpvrymZcWP5NyI1IGhCkAUZu0qacpX3HR0O9SDYP+b27BnNIubxh +GhIRgmkxRI/bYtO/TssLFXZ1zF3NPRcPS+bQ= MIME-Version: 1.0 Received: by 10.224.96.89 with SMTP id g25mr9356690qan.42.1275977633247; Mon, 07 Jun 2010 23:13:53 -0700 (PDT) Received: by 10.220.189.13 with HTTP; Mon, 7 Jun 2010 23:13:53 -0700 (PDT) In-Reply-To: References: <4C07E07B.9060802@cs.rice.edu> <4C09345F.9040300@cs.rice.edu> <4C0D2BEA.6060103@cs.rice.edu> <4C0D3F40.2070101@cs.rice.edu> <20100607202844.GU83316@deviant.kiev.zoral.com.ua> <4C0D64B7.7060604@cs.rice.edu> Date: Tue, 8 Jun 2010 11:43:53 +0530 Message-ID: From: "C. Jayachandran" To: Juli Mallett Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: mips@freebsd.org Subject: Re: svn commit: r208589 - head/sys/mips/mips X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 08 Jun 2010 06:13:55 -0000 On Tue, Jun 8, 2010 at 9:43 AM, Juli Mallett wrote: > Hey JC, > > On Mon, Jun 7, 2010 at 21:07, C. Jayachandran = wrote: >> Yes. I saw the PAE top level page table code and thought I could use >> that mechanism for allocating MIPS page table pages in the direct >> mapped memory. The other reference I used was >> pmap_alloc_zeroed_contig_pages() function in sun4v/sun4v/pmap.c which >> uses the vm_phys_alloc_contig() and VM_WAIT. =A0I had also thought of >> using the VM_FREEPOOL_DIRECT which seemed to be for a similar purpose, >> but could find see any usage in the kernel. > > Do you intend to support o32 kernels in your port indefinitely? =A0I > wonder whether this work is just stopgap until the systems which have > large amounts of RAM can just use n64 kernels. I think the page table work will be needed for o32 and n32, and I would like to support one of them as the preferred 32bit mode for our port. BTW, n32 with >4GB RAM can be supported with XKPHYS for page table entries. The options there would be either special allocator for the segtab (11+9+12 addr space split), or to use special allocator for all the page table pages (10+10+12 split). >=A0At least on Octeon it > seems to me that n64-only is the right answer if at all possible, > since there are really a lot of parts of the kernel that just can't > reasonably work otherwise (use of rman_get_virtual with io ports, for > instance.) Not sure I understand this part - I thought pmap_mapdev() would handle these - but I may be mistaken. JC.