From owner-freebsd-mips@freebsd.org Fri Dec 11 16:38:08 2015 Return-Path: Delivered-To: freebsd-mips@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 4154B9D8CBB for ; Fri, 11 Dec 2015 16:38:08 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: from mail-io0-x236.google.com (mail-io0-x236.google.com [IPv6:2607:f8b0:4001:c06::236]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 138A5187A for ; Fri, 11 Dec 2015 16:38:08 +0000 (UTC) (envelope-from adrian.chadd@gmail.com) Received: by ioc74 with SMTP id 74so131986546ioc.2 for ; Fri, 11 Dec 2015 08:38:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:content-transfer-encoding; bh=rCmuBRQhwgwxbnNN2zVHBwxH2QqC47jeyTs4H4lIg1A=; b=ZVU252RvAQPRvPs2od20uu+HI5orNibGuhMYHMB+bzjczquXDriO4bQa1+f+IbxkiM rRe4gSUjuAZCOoppgxtyP3HGerUUCEAC9vPB12JqpnvtvFXRZRpKRvdCk6BTG/lp+oey 7qDTdlVGRvA0wUneb/CFQKVU37G6GuK0XbFtTgFpDDGxgbo+rmkePODj9ZvD0EqZWDWN POufHde6gtHgDUtTZlknX+chaZPRTlkyuUVT2kSamj0b7b+34IoiDRyWexoGM4qQPC4m /nuXY71Z3QTzTJMFqk2AuMhajhsOgwI4tCtrIsc1qi4Ak6Un1PHM7IgAZ0xs58uKwFxr Cn/A== MIME-Version: 1.0 X-Received: by 10.107.162.21 with SMTP id l21mr16728078ioe.123.1449851887462; Fri, 11 Dec 2015 08:38:07 -0800 (PST) Received: by 10.36.121.202 with HTTP; Fri, 11 Dec 2015 08:38:07 -0800 (PST) In-Reply-To: <7514D462-9B7F-4728-8784-135614215992@gmail.com> References: <7514D462-9B7F-4728-8784-135614215992@gmail.com> Date: Fri, 11 Dec 2015 08:38:07 -0800 Message-ID: Subject: Re: MIPS_CONFIG0_VI defined wrong in sys/mips/include/cpuregs.h? From: Adrian Chadd To: Stanislav Galabov Cc: "freebsd-mips@freebsd.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-BeenThere: freebsd-mips@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Porting FreeBSD to MIPS List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 11 Dec 2015 16:38:08 -0000 Hm, Would you file a freebsd pr about it? I'll go take a look at it and fix it = up. I'll go review the more recent mips core docs and see what's going on too. Thanks! -a On 11 December 2015 at 08:02, Stanislav Galabov wrote: > Hi all, > > It seems that MIPS_CONFIG0_VI is defined wrong in sys/mips/include/cpureg= s.h. > > According to MIPS=C2=AE Architecture For Programmers Volume III, page 149= , Figure 9-29 (Config Register Format), accessed via http://www.t-es-t.hu/d= ownload/mips/md00090c.pdf, bit 3 of config0 is supposed to be VI (Virtual I= nstruction Cache), while the current definition of MIPS_CONFIG0_VI (0x00000= 004) implies that it=E2=80=99s bit 2. > > This leads to a lot of headaches when trying to bring up a new CPU (1004K= C in my case) and trying to use Cachable-Coherent CCA (0x5 or 0b101) for Ks= eg0 :-) > I guess we=E2=80=99ve been able to get away with this so far due to mainl= y 2 things: > 1. CPUs that use CCA 0x4 - 0x7 for Kseg0 usually are cache-coherent anywa= y, so their cache ops are most likely no-op. > 2. CPUs that use CCA 0x0 - 0x3 for Kseg0 work just fine, as bit 2 is not = set :-) > > This leads to improper detection of the I-Cache type (it=E2=80=99s detect= ed as virtual when it actually isn=E2=80=99t) on kernels that use CCA >=3D = 0x4 for Kseg0, which, in turn, leads to a lot of fun trying to figure out w= hat=E2=80=99s wrong and why things work with CCA 0x3 and not with 0x5 on a = single core... > After changing the definition of MIPS_CONFIG0_VI from 0x00000004 to 0x000= 00008 everything goes back to normal even with CCA 0x5. > > I would appreciate it if someone would commit this change (if you guys th= ink it=E2=80=99s necessary). I would do it myself if I but I have no commit= privileges. > > Best wishes, > Stanislav > _______________________________________________ > 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"