From nobody Tue Feb 10 13:17:49 2026 Delivered-To: importer@patchew.org Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail(p=none dis=none) header.from=gmail.com ARC-Seal: i=1; a=rsa-sha256; t=1614121208; cv=none; d=zohomail.com; s=zohoarc; b=eNvGbu6lHn3BXO2zAG4Bl2D/ockr02sO7+bLbVjwcTOxYsn+DhrqDeVu4CQNrXA4P/bWTuleXdgfA1mHwV7gXNuY7oGg00VSrd5YKBRqGj5N5FCwIBNpBTxuCeqQikzEfGdMddqbyFNlneniMsokWaBWmpyJFc/KvxWZKe5/He0= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1614121208; h=Content-Type:Content-Transfer-Encoding:Cc:Date:From:In-Reply-To:List-Subscribe:List-Post:List-Id:List-Archive:List-Help:List-Unsubscribe:MIME-Version:Message-ID:References:Sender:Subject:To; bh=kFj03blwbcM66TuxYye9XnlpLa3NkLZCnKGhAwTXsCo=; b=g6dXVTOionJsHtPOXtPR+mtLRfb9oTle3Tk1bL8ELk5d6377pepTEsBdM0S+dKejALpKUDkKg+HS/PcFIZOpFlpBnEE5VyLF0PRiY9Uh18qTEI8npddnsnVaW07j2yeVe4gfjV6Va1eef/R7IXW/dRuwAxhlxJ24vmgdJlJ7hAk= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=fail; spf=pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; dmarc=fail header.from= (p=none dis=none) header.from= Return-Path: Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) by mx.zohomail.com with SMTPS id 1614121208152248.05370182403885; Tue, 23 Feb 2021 15:00:08 -0800 (PST) Received: from localhost ([::1]:49258 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lEgf1-0007a9-1A for importer@patchew.org; Tue, 23 Feb 2021 18:00:07 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:48058) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lEgZ8-0002AM-0m; Tue, 23 Feb 2021 17:54:03 -0500 Received: from mail-ej1-x634.google.com ([2a00:1450:4864:20::634]:33915) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lEgZ5-00022d-02; Tue, 23 Feb 2021 17:54:01 -0500 Received: by mail-ej1-x634.google.com with SMTP id hs11so91540ejc.1; Tue, 23 Feb 2021 14:53:58 -0800 (PST) Received: from localhost.localdomain (2a02-a456-6be8-1-9f7b-4035-6320-cb66.fixed6.kpn.net. [2a02:a456:6be8:1:9f7b:4035:6320:cb66]) by smtp.gmail.com with ESMTPSA id u15sm55752ejy.48.2021.02.23.14.53.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 23 Feb 2021 14:53:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=kFj03blwbcM66TuxYye9XnlpLa3NkLZCnKGhAwTXsCo=; b=ojkRGJkRsPNeqiOoXgOpmpfHhd3y3FD+hD49ccnwgx8h5kCp/oS3/IMxPMGzSmv8XF 44agrTSkH/5Yw3Aadj7GxDhFCnQG2w/R+U8l87+kPMgIlmbrWhTPfjC0WDk6K2Dug5lg j7EBxguSjnIrH6dqEVa+gdtJYuDz4p133M6V+EK/fI6bgZXAJDLyhjLpBv3mW6gVnCks ww/WDkj0BMshOGkIhUaDUYDzn2tADdmJymrSAGd3uML6QhL5yNRcLEix151weS73kazf rSy72WietYapCkjknlSdjm7FEJU22522hBkeBXSzWppPW1AJDwlqQMgbDmOGxMmu8MxT +M4Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=kFj03blwbcM66TuxYye9XnlpLa3NkLZCnKGhAwTXsCo=; b=CfPTbNCmI7GTqnCpfPfDEJeLRH03WXlkr6HueLqmn6J5qDvneDbKJBHvDop5BWlBiY gn/UNLF+Df3zlxsr3RzubJ0Tr2Z8rOgpvqEBChhiQdqhV23C1qF6coy/o43CPp4Gw7Cu Cx1IP6prnQk0FqSLL7rVsUemzjxO0hWQYdoPLGp3CVhTKBJpSpoCGW0Q6HG7JbW/qD8Q FNH/ihN+ml54KzMNj4MRHoHD3GJHl2hBSXDbzswGpMVreG25ZjDBfNm7Fah3vpDAmdz+ ML1LHxXOwYN/akx5/HaiAD0f900sEsJ/prgxSfyG1EIkgtgC2ktFF+ImtfQZ1MwObukK upxg== X-Gm-Message-State: AOAM530JFbxw7cH0s0Vm6pabZtBx6v0RjP7c34bZ3brNla0ozS00Z4AW MMayKpiiP1a5S0mD6td0fiZApWH5HNc= X-Google-Smtp-Source: ABdhPJyYrWm8NHnNLdQVv1pI3RgIpQ4NEWJqJSicPKHJjeWMq2vXpWtrFeBKTtnPECNUIqSvptuFzw== X-Received: by 2002:a17:907:9619:: with SMTP id gb25mr9262235ejc.64.1614120837252; Tue, 23 Feb 2021 14:53:57 -0800 (PST) From: Niek Linnenbank To: qemu-devel@nongnu.org Subject: [PATCH v2 2/2] hw/net/allwinner-sun8i-emac: traverse transmit queue using TX_CUR_DESC register value Date: Tue, 23 Feb 2021 23:53:27 +0100 Message-Id: <20210223225327.26700-3-nieklinnenbank@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210223225327.26700-1-nieklinnenbank@gmail.com> References: <20210223225327.26700-1-nieklinnenbank@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=2a00:1450:4864:20::634; envelope-from=nieklinnenbank@gmail.com; helo=mail-ej1-x634.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, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action 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: peter.maydell@linaro.org, f4bug@amsat.org, b.galvani@gmail.com, Niek Linnenbank , qemu-arm@nongnu.org, Pavel.Dovgaluk@ispras.ru, crosa@redhat.com, philmd@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) Currently the emulated EMAC for sun8i always traverses the transmit queue from the head when transferring packets. It searches for a list of consecut= ive descriptors whichs are flagged as ready for processing and transmits their = payloads accordingly. The controller stops processing once it finds a descriptor tha= t is not marked ready. While the above behaviour works in most situations, it is not the same as t= he actual EMAC in hardware. Actual hardware uses the TX_CUR_DESC register value to ke= ep track of the last position in the transmit queue and continues processing from th= at position when software triggers the start of DMA processing. The currently emulated = behaviour can lead to packet loss on transmit when software fills the transmit queue with= ready descriptors that overlap the tail of the circular list. This commit modifies the emulated EMAC for sun8i such that it processes the transmit queue using the TX_CUR_DESC register in the same way as hardwa= re. Signed-off-by: Niek Linnenbank Reviewed-by: Philippe Mathieu-Daud=C3=A9 --- hw/net/allwinner-sun8i-emac.c | 58 +++++++++++++++++++---------------- 1 file changed, 32 insertions(+), 26 deletions(-) diff --git a/hw/net/allwinner-sun8i-emac.c b/hw/net/allwinner-sun8i-emac.c index 042768922c..e586c147e5 100644 --- a/hw/net/allwinner-sun8i-emac.c +++ b/hw/net/allwinner-sun8i-emac.c @@ -339,35 +339,40 @@ static void allwinner_sun8i_emac_update_irq(AwSun8iEm= acState *s) qemu_set_irq(s->irq, (s->int_sta & s->int_en) !=3D 0); } =20 -static uint32_t allwinner_sun8i_emac_next_desc(AwSun8iEmacState *s, - FrameDescriptor *desc, - size_t min_size) +static bool allwinner_sun8i_emac_desc_owned(FrameDescriptor *desc, + size_t min_buf_size) { - uint32_t paddr =3D desc->next; + return (desc->status & DESC_STATUS_CTL) && (min_buf_size =3D=3D 0 || + (desc->status2 & DESC_STATUS2_BUF_SIZE_MASK) >=3D min_buf_size); +} =20 - dma_memory_read(&s->dma_as, paddr, desc, sizeof(*desc)); +static void allwinner_sun8i_emac_get_desc(AwSun8iEmacState *s, + FrameDescriptor *desc, + uint32_t phys_addr) +{ + dma_memory_read(&s->dma_as, phys_addr, desc, sizeof(*desc)); +} =20 - if ((desc->status & DESC_STATUS_CTL) && - (desc->status2 & DESC_STATUS2_BUF_SIZE_MASK) >=3D min_size) { - return paddr; - } else { - return 0; - } +static uint32_t allwinner_sun8i_emac_next_desc(AwSun8iEmacState *s, + FrameDescriptor *desc) +{ + const uint32_t nxt =3D desc->next; + allwinner_sun8i_emac_get_desc(s, desc, nxt); + return nxt; } =20 -static uint32_t allwinner_sun8i_emac_get_desc(AwSun8iEmacState *s, - FrameDescriptor *desc, - uint32_t start_addr, - size_t min_size) +static uint32_t allwinner_sun8i_emac_find_desc(AwSun8iEmacState *s, + FrameDescriptor *desc, + uint32_t start_addr, + size_t min_size) { uint32_t desc_addr =3D start_addr; =20 /* Note that the list is a cycle. Last entry points back to the head. = */ while (desc_addr !=3D 0) { - dma_memory_read(&s->dma_as, desc_addr, desc, sizeof(*desc)); + allwinner_sun8i_emac_get_desc(s, desc, desc_addr); =20 - if ((desc->status & DESC_STATUS_CTL) && - (desc->status2 & DESC_STATUS2_BUF_SIZE_MASK) >=3D min_size) { + if (allwinner_sun8i_emac_desc_owned(desc, min_size)) { return desc_addr; } else if (desc->next =3D=3D start_addr) { break; @@ -383,14 +388,14 @@ static uint32_t allwinner_sun8i_emac_rx_desc(AwSun8iE= macState *s, FrameDescriptor *desc, size_t min_size) { - return allwinner_sun8i_emac_get_desc(s, desc, s->rx_desc_curr, min_siz= e); + return allwinner_sun8i_emac_find_desc(s, desc, s->rx_desc_curr, min_si= ze); } =20 static uint32_t allwinner_sun8i_emac_tx_desc(AwSun8iEmacState *s, - FrameDescriptor *desc, - size_t min_size) + FrameDescriptor *desc) { - return allwinner_sun8i_emac_get_desc(s, desc, s->tx_desc_head, min_siz= e); + allwinner_sun8i_emac_get_desc(s, desc, s->tx_desc_curr); + return s->tx_desc_curr; } =20 static void allwinner_sun8i_emac_flush_desc(AwSun8iEmacState *s, @@ -470,7 +475,8 @@ static ssize_t allwinner_sun8i_emac_receive(NetClientSt= ate *nc, bytes_left -=3D desc_bytes; =20 /* Move to the next descriptor */ - s->rx_desc_curr =3D allwinner_sun8i_emac_next_desc(s, &desc, 64); + s->rx_desc_curr =3D allwinner_sun8i_emac_find_desc(s, &desc, desc.= next, + AW_SUN8I_EMAC_MIN= _PKT_SZ); if (!s->rx_desc_curr) { /* Not enough buffer space available */ s->int_sta |=3D INT_STA_RX_BUF_UA; @@ -495,10 +501,10 @@ static void allwinner_sun8i_emac_transmit(AwSun8iEmac= State *s) size_t transmitted =3D 0; static uint8_t packet_buf[2048]; =20 - s->tx_desc_curr =3D allwinner_sun8i_emac_tx_desc(s, &desc, 0); + s->tx_desc_curr =3D allwinner_sun8i_emac_tx_desc(s, &desc); =20 /* Read all transmit descriptors */ - while (s->tx_desc_curr !=3D 0) { + while (allwinner_sun8i_emac_desc_owned(&desc, 0)) { =20 /* Read from physical memory into packet buffer */ bytes =3D desc.status2 & DESC_STATUS2_BUF_SIZE_MASK; @@ -524,7 +530,7 @@ static void allwinner_sun8i_emac_transmit(AwSun8iEmacSt= ate *s) packet_bytes =3D 0; transmitted++; } - s->tx_desc_curr =3D allwinner_sun8i_emac_next_desc(s, &desc, 0); + s->tx_desc_curr =3D allwinner_sun8i_emac_next_desc(s, &desc); } =20 /* Raise transmit completed interrupt */ --=20 2.25.1