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[2a02:a456:6be8:1:ebf2:7b2:6f3d:5954]) by smtp.gmail.com with ESMTPSA id t8sm289956edv.16.2021.03.04.12.35.53 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 04 Mar 2021 12:35:53 -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=ZPNU1XIveNLCQj0m/Hv+rSR2fxKvOhEBf9TpxLzoTgeWfhh/iEUTuGmr4IdNBW56KH ZtEAkXGB5X5x0yDOEXIYpdnBQUCgiyR4bRzrSbc3jMsNVdxe4T+AspNbavIXOaggwOOC yrZqFGNFFy1ayd8hQUwayCLSTV7rT4XonFBsYgJ7o26R8GwfnAOXG1obmdYiPWaSNreu 7n71stLpGfZvXrtgcgxUADR4iH0qGJCrZX1CsiW2bRr0epGjSgF87S9JRSm/NddtUziw EMbMgG5bAXhcb1JcRTVzQlMOo5hfkRlK7CK1YI8Ey7c5gNdU/xWZrMEFPnYQU/LwzeYp DKrw== 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=eHVJfYe/kRWgZ5iFxUBPGA8MsAZ9mI+BkY97+BfebD1H6JG1x8+pvfygHl628Y0bvU MBp9CawVWbVDzpVyFvOiMpIQdEeaL/G8715lcjoBXspQF6zoKzK2lY/Q0t/EhXjYIimc LbcbMz8nUs5DmHReizdLdGghPYD4TNb+ebINfkkL8rUxSZLucf1hy12ACgzgUs+t/fe8 4vZmPVMveMreD5cl4178MR+8UTibRIkYM9JNxqX9dcloAEWvuhMQyVxg18oZdBX/Fasd Ll7vqnj4vurcfSid32Cv30rHww7p4vfHH/hq711cF0p8ditQF4GACXUldQxNHAADWzRg JqVQ== X-Gm-Message-State: AOAM530z6468y2Pz0FJANTFxno3Xb1MJI/++KG2ZqPLAn2mzAQ9rzu6e E+EHDBNHsZDxwvQwueCqEZqhVO91VAsX3w== X-Google-Smtp-Source: ABdhPJx1u2pOp5Hm9SEKoNfc+tVXeqm+9U8M/A23G9McmeWk0f/aZNhH3j6/Zp0GCwgCc55gqhOImw== X-Received: by 2002:a17:906:32da:: with SMTP id k26mr4740008ejk.483.1614890154363; Thu, 04 Mar 2021 12:35:54 -0800 (PST) From: Niek Linnenbank To: qemu-devel@nongnu.org Subject: [PATCH v3 1/5] hw/net/allwinner-sun8i-emac: traverse transmit queue using TX_CUR_DESC register value Date: Thu, 4 Mar 2021 21:35:36 +0100 Message-Id: <20210304203540.41614-2-nieklinnenbank@gmail.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20210304203540.41614-1-nieklinnenbank@gmail.com> References: <20210304203540.41614-1-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, thuth@redhat.com, berrange@redhat.com, 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