From owner-freebsd-mips@freebsd.org Thu Dec 13 00:11:55 2018 Return-Path: Delivered-To: freebsd-mips@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 8BF90132B067 for ; Thu, 13 Dec 2018 00:11:55 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: from mail-qk1-x72c.google.com (mail-qk1-x72c.google.com [IPv6:2607:f8b0:4864:20::72c]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 94DB888709 for ; Thu, 13 Dec 2018 00:11:54 +0000 (UTC) (envelope-from wlosh@bsdimp.com) Received: by mail-qk1-x72c.google.com with SMTP id q70so149193qkh.6 for ; Wed, 12 Dec 2018 16:11:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bsdimp-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=AeXtHP2FGTXP2q1DW5UOUD90HNq59XQzxDxVZpjCDms=; b=epelE65G7uCO0KLb8aKFNRSBdkgajED6d7gsnIbV+xwa/ozHvnjCPtBRxTozBfiFPF cQ+ggRnAQVvwJ8IEEWd6vABSxwCaO7v0Fhbd/NiBZNdgXySX93LA42qJpneWo/Z+4082 9rKtj2WDFDZvfA++Bd6XODO5pyV1S+mi78UowLdbnD9r0ozmHM9dhWzzKmw6e+/TyyYp tA7hQHsIib81xrY92z1L01IaYiEaDY2JN4GpvsyoV/6XQdt3RDdy+oNCcRCeJ8iY7GDj JBiHElmw3q1oeuOJ+a67izzYCk28yJEeTLk6LdO3h+atlGnYsGFZK2jIMssSyv3i/Zxc Fgkg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=AeXtHP2FGTXP2q1DW5UOUD90HNq59XQzxDxVZpjCDms=; b=UkPqqng5WZQGvknesfPvA+J/KWox2wddtwM6lRMKrRsQRDAF8hP+iX5h/zkHBQENNk vdTCyl37zCmMmZjQCfl9w0CdJvo06drr9q1DnVqE5P32XCU/wtPu51wDXSbVy77Nbs6J e5lBPUTtO96IcuZCpGr8IDn3HL6mnWcdi9fKzym6XzRoY95pwuJoqhqYNSZ5DJlJxEtY 8R5C4RM8A1UPkzK/VxPOmrxqjneS6GTCMj/IFJKP4yD2GbxlWujiacN+7gMPWdrSAMQl ZuT1K5eFTAPMREjQFiXWeNQsNcebw++Efty/nGgRz36wad8Lc10iGtXjqEt2Ub+i2YK4 qxAA== X-Gm-Message-State: AA+aEWYMmYavol9OV8q+77Sudjrv3obgiEdpx/1XZm9mlWq2PPjRoneq PbPpIgE0/4PCntFO8HNqEgRtMMPWvg5WjAIZEwbTvQ34 X-Google-Smtp-Source: AFSGD/W7YjrPxMvzYUB/F3PG+G+fIsy++LgEQAMuXpmNSfC6uJJ5jZ67jF7vwGs4K2v4T+stQh8PIjQmcW1vXZqRZz0= X-Received: by 2002:a37:9201:: with SMTP id u1mr20897448qkd.258.1544659913865; Wed, 12 Dec 2018 16:11:53 -0800 (PST) MIME-Version: 1.0 References: <367298.45441.qm@web103901.mail.ssk.yahoo.co.jp> In-Reply-To: <367298.45441.qm@web103901.mail.ssk.yahoo.co.jp> From: Warner Losh Date: Wed, 12 Dec 2018 17:11:43 -0700 Message-ID: Subject: Re: MIPS future... To: Mori Hiroki Cc: "freebsd-mips@freebsd.org" X-Rspamd-Queue-Id: 94DB888709 X-Spamd-Bar: ---- Authentication-Results: mx1.freebsd.org; dkim=pass header.d=bsdimp-com.20150623.gappssmtp.com header.s=20150623 header.b=epelE65G X-Spamd-Result: default: False [-4.49 / 15.00]; ARC_NA(0.00)[]; TO_DN_EQ_ADDR_SOME(0.00)[]; R_DKIM_ALLOW(-0.20)[bsdimp-com.20150623.gappssmtp.com:s=20150623]; NEURAL_HAM_MEDIUM(-0.99)[-0.990,0]; FROM_HAS_DN(0.00)[]; TO_DN_SOME(0.00)[]; NEURAL_HAM_SHORT(-0.98)[-0.983,0]; MIME_GOOD(-0.10)[multipart/alternative,text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-mips@freebsd.org]; DMARC_NA(0.00)[bsdimp.com]; TO_MATCH_ENVRCPT_SOME(0.00)[]; MX_GOOD(-0.01)[cached: ALT1.aspmx.l.google.com]; DKIM_TRACE(0.00)[bsdimp-com.20150623.gappssmtp.com:+]; RCPT_COUNT_TWO(0.00)[2]; RCVD_IN_DNSWL_NONE(0.00)[c.2.7.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.4.6.8.4.0.b.8.f.7.0.6.2.list.dnswl.org : 127.0.5.0]; R_SPF_NA(0.00)[]; FORGED_SENDER(0.30)[imp@bsdimp.com,wlosh@bsdimp.com]; FREEMAIL_TO(0.00)[yahoo.co.jp]; MIME_TRACE(0.00)[0:+,1:+]; RCVD_TLS_LAST(0.00)[]; ASN(0.00)[asn:15169, ipnet:2607:f8b0::/32, country:US]; FROM_NEQ_ENVFROM(0.00)[imp@bsdimp.com,wlosh@bsdimp.com]; IP_SCORE(-2.50)[ip: (-9.57), ipnet: 2607:f8b0::/32(-1.57), asn: 15169(-1.29), country: US(-0.09)]; RCVD_COUNT_TWO(0.00)[2] Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.29 X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 13 Dec 2018 00:11:55 -0000 On Wed, Dec 12, 2018 at 3:53 PM Mori Hiroki wrote: > > > Hi > > > ----- Original Message ----- > >From: Warner Losh > >To: "freebsd-mips@freebsd.org" > >Date: 2018/12/13, Thu 07:15 > >Subject: Re: MIPS future... > > > >On Wed, Dec 12, 2018 at 11:15 AM Warner Losh wrote: > > > >> OK. To be a good player in the FreeBSD ecosystem, we need to do a few > >> things. > >> > >> First, we need to implement atomic_swap_64. hps did this for mips64 and > >> committed it. He sent me some further patches for it that I need to > commit > >> when I get a change, maybe at the airport tonight. > >> > >> But this brings up a couple of issues I'd like to bring up. > >> > >> First, to implement atomic_swap_64 on mips-32 is hard. In that it's not > >> just the canonical ldd/sdd sequence because those aren't available > there. > >> We can do the standard trick of reading STATUS0, clearing IE, storing > it, > >> do the operation and then restoring STATUS0. This is efficient enough > for > >> the use in the kernel for the supported cores we have. > >> > >> With two exceptions. First is running 32-bit kernels on 64-bit hardware. > >> We deprecated that with Octeon because of the weird hacks we needed to > do > >> too make it work. I'd like to universally deprecate this. There's little > >> benefit and a real cost to doing this. I'd like to remove the SWARM_SMP, > >> XLP, and GXEMUL32 (or at least remove the smp option). > >> > >> But there's JZ4780. It's a legit mips32 + SMP. It's on Image Creator's > >> CI20. This was released in Nov 2014 with a refresh in March 2015. This > is a > >> dead-end product line (there's no new cores and none new that I can > find). > >> This was a RPi competitor, but it was slower, less capable and more > >> expensive so it's kinda rare now. I'd say we need to de-support this > >> device. I know of only one user, and he's not responded to my email. I > >> think 12 will have to be the last release we have this in. Today, the > only > >> affect is for some drivers that can't run on this platform, but the > writing > >> is on the wall. > >> > >> That brings me to my next question: SWARM. Can we kill SWARM entirely? > >> It's for the BCM1250 part, released in sometime before 2000. It was > super > >> popular because it was the reference for a ton of things that followed. > I > >> think it's run is over and we can remove it. I can find no users of it > in > >> the nyc dmesg database. Mine has been in a plastic bag since before my > sone > >> was born in 2006... So I'm thinking we can remove this platform. It was > on > >> the edge last time I did a GC in mips-land. > >> > >> And then there's the even larger question: how many people are still > using > >> mips32? It looks like a fair number, maybe, but I have no idea for > sure, so > >> if you do, please provide feedback on the platforms you are running > FreeBSD > >> 11 or newer on. > >> > > > >There's one last issue this brings up. When writing the above code, I > >discovered I could use the non-racy DI instruction. However, that was > >introduced with mips32r2. This was defined in 2002 and gear appeared in > the > >market 2004 or 2005. I believe that all supported SoCs have mips32r2. > SWARM > >doesn't, which is another reason to kill it: it's getting in the way and > >providing no benefit. Would anybody object to the minimum ISA being raised > >to mips32r2 for all 32-bit mips platforms? > > > >Warner > >_______________________________________________ > >freebsd-mips@freebsd.org mailing list > >https://lists.freebsd.org/mailman/listinfo/freebsd-mips > >To unsubscribe, send any mail to "freebsd-mips-unsubscribe@freebsd.org" > > > > > > > > mips32 is called by 4K > mips32r2 is called by 24K > > In current FreeBSD mips support at 4K is Rakink RT2880 and Atheros > AR531x. Ralink RT3050 later and Newer Atheros is 24K or 74K. > OK. That's good to know. The AR531x boards generally are under-provisioned for memory, and somewhat slow. The RT2880 appears to be in the same class. I'd be quite surprised if anybody could do anything non-trivial with those boards. Also Broadcom BCM4712 and BCM5354 is 4K but it's still hangup. Last > Broadcom MIPS soc that is BCM4718 and BCM5357 is 74K. > So the older SENTRY5 chips, which weren't all that common, but which are definitely mips4k chips. They are only a little better than the AR531x chips. The newer BCM stuff still looks relevant. Thanks for the pointers. I have question. Can do generate 24K code by gcc 4.2.1 and binutils? > I think that adding the following to the config file makeoptions ARCH_FLAGS="-march=mips32r2" comes close. You may need too add -EL if it's little endian. The only other config file tagged MIPS4k is GXEMUL, which may have run its useful lifetime in FreeBSD as well. Warner P.S. I'll post a summary of the implications of mips32"r1" removal if there's any opposition.