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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id ECF75C25B76 for ; Mon, 3 Jun 2024 15:33:15 +0000 (UTC) Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sE9fk-0005WS-H6; Mon, 03 Jun 2024 11:32:32 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sE9ff-0005Vo-GS for qemu-devel@nongnu.org; Mon, 03 Jun 2024 11:32:30 -0400 Received: from mail-wm1-x336.google.com ([2a00:1450:4864:20::336]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1sE9fd-0000PX-J4 for qemu-devel@nongnu.org; Mon, 03 Jun 2024 11:32:27 -0400 Received: by mail-wm1-x336.google.com with SMTP id 5b1f17b1804b1-421392b8156so13412915e9.3 for ; Mon, 03 Jun 2024 08:32:25 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; t=1717428744; x=1718033544; darn=nongnu.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=kttWk285TmQlKiM54Fl/VNgnRVpdriyOBrecjCQJlxY=; b=paDn2Eblos8RiiXhsxe3WF72/UsfXmnNc5bX0sL14Bj53NMawT30R7QA+Jldm0Nf9N BGaCKM8o5DdZQl51ORYo/8gIr4lNlv/uMYnRtS3nGUQTNZscQ86c9qaBuuaFxG2sLZXZ b0t0tEb81DP/9W1W7rOLzAH9biW3nO52dUDokN98u5WS9B/KSNSDfJaCz42Iv1pXHT4L P52EZanwKXHe477UeP42uTVSuBPgSWu8b70PATinP6BApRx2ZHNgq0T/mjy0INDLzFam UywOX6PuJCg0riuvg7fnhdzZk8TKqJThnKJ+ASf/bpGMYff2vQKRQ82iHkAKM2zoKR+a G3Cw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1717428744; x=1718033544; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=kttWk285TmQlKiM54Fl/VNgnRVpdriyOBrecjCQJlxY=; b=Gxnhnd5Om9Qudnxd1ScvQK/oSIfqC4ZJTnNhIcTVCVNEFVh2nuZCMlXQkwGoiHPhsD ixJeWQuZLhCKWRiR39ZyIcDi/OTUOpRKPFTM6QX6c1rnpVk+7VCz5P/NyTQpCHlSayqi vCEzNM7ziVh5ZUTO7GrXnq2FkDf+cBd2r9zHRwEUGEup746IlHkR6bSTe3TnaE53waiK bMqqAdMIzYWsi/KudiG+tIv1dm7mplQUxkOdMm2P65VRcFPvYGjJfZAI7XeDMwLV2YpP GnOMXWrOTWhuIlItX1+3HJi6X+oyZQWVXH699SnedSOnlBMzClEPEO3z2bRbhyXjCvHW 5c/w== X-Forwarded-Encrypted: i=1; AJvYcCVh2xbtepYmzFsKQLD+oeKMgsruVVSZM5V7jGNYHFOXqdx7DWZLE+N9sWpsEr+kwy3bGPz5hj6cv3wWvgDHKbFZa1JwLz4= X-Gm-Message-State: AOJu0YzOakrpboxnoB1n9FyWGbYycILIi5/KV0fKkXn58JCHPlziPbQc FkP2AeZWgIv5xzsx072uaIdHU95bf2zYRBb1PXzRcFPpJvwdhobVfigwW50odMo= X-Google-Smtp-Source: AGHT+IH6om7N+0vFQd82bSP5LWS2wIE47XJ8T38nfsW+/Lg7jPuuZOuDWbKu7N3P5Zl0k1aTNofNOQ== X-Received: by 2002:a05:600c:1d25:b0:421:2a54:2f1d with SMTP id 5b1f17b1804b1-4212e061399mr85571975e9.17.1717428743516; Mon, 03 Jun 2024 08:32:23 -0700 (PDT) Received: from [192.168.69.100] ([176.176.177.241]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4212b84de44sm120383785e9.11.2024.06.03.08.32.22 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 03 Jun 2024 08:32:22 -0700 (PDT) Message-ID: <6c1de896-c2fb-4772-b3f9-bd2b6175090e@linaro.org> Date: Mon, 3 Jun 2024 17:32:21 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] hw/mips/loongson3_virt: Implement node counter timer To: Jiaxun Yang , qemu-devel@nongnu.org Cc: Huacai Chen References: <20240512-loongson3_hpt-v1-1-5cb9cbae649b@flygoat.com> Content-Language: en-US From: =?UTF-8?Q?Philippe_Mathieu-Daud=C3=A9?= In-Reply-To: <20240512-loongson3_hpt-v1-1-5cb9cbae649b@flygoat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=2a00:1450:4864:20::336; envelope-from=philmd@linaro.org; helo=mail-wm1-x336.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Hi Jiaxun, On 12/5/24 14:20, Jiaxun Yang wrote: > Node counter is a timer presents on Loongson-3 chips, which runs > as fast as CPU clock. It's being mapped into a MMIO location. > > Emulate this for loongson3_virt machine, in hope that kernel can > use it as a better clock source. > > Hardware's behavior on 32-bit read/write is also emulated in case > legacy kernel is trying to use it with hi/lo splitted read. > > Signed-off-by: Jiaxun Yang > --- > hw/mips/loongson3_bootp.h | 1 + > hw/mips/loongson3_virt.c | 38 ++++++++++++++++++++++++++++++++++---- > 2 files changed, 35 insertions(+), 4 deletions(-) > +static uint64_t loongson3_nodecnt_read(void *opaque, > + hwaddr addr, unsigned size) > +{ > + LoongsonMachineState *s = opaque; > + int64_t now_ns = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); > + uint64_t ticks = clock_ns_to_ticks(s->cpuclk, now_ns); > + > + if (addr == 0x4) { > + return ticks >> 32; Does that imply .endianness = DEVICE_BIG_ENDIAN? It could be simpler to let the core MMIO code do the hi/lo bits management using ".impl.min_access_size = 8". > + } > + > + return ticks; > +} > + > +static const MemoryRegionOps loongson3_nodecnt_ops = { > + .read = loongson3_nodecnt_read, > + .endianness = DEVICE_NATIVE_ENDIAN, > + .valid.min_access_size = 4, > + .valid.max_access_size = 8, > + .impl.min_access_size = 4, > + .impl.max_access_size = 8, > +};