From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E0B92C32753 for ; Tue, 13 Aug 2019 22:55:24 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B530E2067D for ; Tue, 13 Aug 2019 22:55:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B530E2067D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=sifive.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:56032 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hxfhM-0006pM-2E for qemu-devel@archiver.kernel.org; Tue, 13 Aug 2019 18:55:24 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:56745) by lists.gnu.org with esmtp (Exim 4.86_2) (envelope-from ) id 1hxfgn-0005tr-Bk for qemu-devel@nongnu.org; Tue, 13 Aug 2019 18:54:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1hxfgm-0006Ux-52 for qemu-devel@nongnu.org; Tue, 13 Aug 2019 18:54:49 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:39740) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1hxfgl-0006Um-WB for qemu-devel@nongnu.org; Tue, 13 Aug 2019 18:54:48 -0400 Received: by mail-pg1-f193.google.com with SMTP id u17so52015891pgi.6 for ; Tue, 13 Aug 2019 15:54:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:subject:in-reply-to:cc:from:to:message-id :mime-version:content-transfer-encoding; bh=pD5kV7hqiohLthOgANLe54vWSLciZL41msmXwMzBgK4=; b=OiljFS1jXtw9A3LKOlFRfJnY2OaC5UN28KQkBtJkMDyD6re8la/T5E3omEOkU8sMUD kAsht/yQfr6YN8g9KPe/qU83gP6zDYbbq0tw/CxFsKT6uF1l74gx+hzih3vp17sGowM3 N/MPw/zJubS0LnWS9GxraJfeRjfzLrdc/nP4j1m64EBnez7i8rs84V+NFfY3a8KYBnP2 WibLfDR+cqnxpQdGxLd6XiAKsEWJ+eaK5Ur9eotaLIkM+FJDeo7ZN54HiD55E9sXPbIG 6Cv+O1G8pmakL+Mjy7x9U6V/EPXvMVffVtH9vWyyfu6SYOQwyBfdCEzTKkJ27iXw0jbK yycw== X-Gm-Message-State: APjAAAVvmVMZCohS+a3+3x4Y4lfjeYBkXD9BstPQk0zeROSvdOr8CPMd ElQhDe4r+hrpGLOH2yF1cTYEuw== X-Google-Smtp-Source: APXvYqx4mBueSQ5W6b0hWa/YZxUwGK9etC0eIax1zALote8GRc+iqy9JOQmHgXUL3knOiux0707hwQ== X-Received: by 2002:a63:2744:: with SMTP id n65mr35890254pgn.277.1565736886585; Tue, 13 Aug 2019 15:54:46 -0700 (PDT) Received: from localhost ([12.206.222.5]) by smtp.gmail.com with ESMTPSA id v184sm108447072pfb.82.2019.08.13.15.54.45 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Aug 2019 15:54:46 -0700 (PDT) Date: Tue, 13 Aug 2019 15:54:46 -0700 (PDT) X-Google-Original-Date: Tue, 13 Aug 2019 15:53:41 PDT (-0700) In-Reply-To: From: Palmer Dabbelt To: alistair23@gmail.com Message-ID: Mime-Version: 1.0 (MHng) Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.85.215.193 Subject: Re: [Qemu-devel] [PATCH for 4.1] RISC-V: Ignore the S and U extensions when formatting ISA strings X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alistair Francis , Paul Walmsley , qemu-riscv@nongnu.org, qemu-devel@nongnu.org, Atish Patra Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, 07 Aug 2019 10:54:52 PDT (-0700), alistair23@gmail.com wrote: > On Wed, Aug 7, 2019 at 8:00 AM Palmer Dabbelt wrote: >> >> The ISA strings we're providing from QEMU aren't actually legal RISC-V >> ISA strings, as both the S and U extensions cannot exist as >> single-letter extensions and must instead be multi-letter strings. >> We're still using the ISA strings inside QEMU to track the availiable > > s/availiable/available/g > >> extensions, so this patch just strips out the S and U extensions when >> formatting ISA strings. > > Atish and I were talking about this and we concluded that S and U > aren't extensions, but should be reported in the misa CSR. Andrew agrees. > >> >> This boots Linux on top of 4.1-rc3, which no longer has the U extension >> in /proc/cpuinfo. >> >> Signed-off-by: Palmer Dabbelt >> --- >> This is another late one, but I'd like to target it for 4.1 as we're >> providing illegal ISA strings and I don't want to bake that into a bunch >> of other code. >> --- >> target/riscv/cpu.c | 17 ++++++++++++++++- >> 1 file changed, 16 insertions(+), 1 deletion(-) >> >> diff --git a/target/riscv/cpu.c b/target/riscv/cpu.c >> index f8d07bd20ad7..4df14433d789 100644 >> --- a/target/riscv/cpu.c >> +++ b/target/riscv/cpu.c >> @@ -501,7 +501,22 @@ char *riscv_isa_string(RISCVCPU *cpu) >> char *p = isa_str + snprintf(isa_str, maxlen, "rv%d", TARGET_LONG_BITS); >> for (i = 0; i < sizeof(riscv_exts); i++) { >> if (cpu->env.misa & RV(riscv_exts[i])) { >> - *p++ = qemu_tolower(riscv_exts[i]); >> + char lower = qemu_tolower(riscv_exts[i]); >> + switch (lower) { >> + case 's': >> + case 'u': >> + /* >> + * The 's' and 'u' extensions shouldn't be passed in the device >> + * tree, but we still use them internally to track extension >> + * sets. Here we just explicitly remove them when formatting >> + * an ISA string. > > This should be updated to note mention 's' and 'u' as extensions, but > clarify that they are correctly include in the misa CSR. I'll send a v2 that cleans up the wording on the comment and commit message. > > Alistair > >> + */ >> + break; >> + >> + default: >> + *p++ = qemu_tolower(riscv_exts[i]); >> + break; >> + } >> } >> } >> *p = '\0'; >> -- >> 2.21.0 >> >>