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[146.241.238.90]) by smtp.gmail.com with ESMTPSA id 10-20020a05600c22ca00b0040ef8aa4822sm4136433wmg.38.2024.02.01.03.41.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 01 Feb 2024 03:41:33 -0800 (PST) Message-ID: Subject: Re: [PATCH v2 1/6] net: wan: Add support for QMC HDLC From: Paolo Abeni To: Herve Codina , Vadim Fedorenko , "David S. Miller" , Eric Dumazet , Jakub Kicinski Date: Thu, 01 Feb 2024 12:41:32 +0100 In-Reply-To: <20240130084035.115086-2-herve.codina@bootlin.com> References: <20240130084035.115086-1-herve.codina@bootlin.com> <20240130084035.115086-2-herve.codina@bootlin.com> Autocrypt: addr=pabeni@redhat.com; prefer-encrypt=mutual; keydata=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 7ZxN9ZsDL38qVIuFkSpgMZCiUHdxBC11J8nbBSLlpnc924UAyr5XrGA99 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 iWjoCy8L35zPqR5TV+f5WR5hTVCqmLHSgm1jxwKhPg9L+GfuE4d0SWd84y 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 sD2W1U7eyLdm/jCgticGDsRtweytsgCSYfbz0gdgUuL3EBYN3JLbAU+UZpy 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 User-Agent: Evolution 3.50.3 (3.50.3-1.fc39) MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrew Lunn , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Mark Brown , Thomas Petazzoni , linuxppc-dev@lists.ozlabs.org Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Tue, 2024-01-30 at 09:40 +0100, Herve Codina wrote: > The QMC HDLC driver provides support for HDLC using the QMC (QUICC > Multichannel Controller) to transfer the HDLC data. >=20 > Signed-off-by: Herve Codina > Reviewed-by: Christophe Leroy > Acked-by: Jakub Kicinski > --- > drivers/net/wan/Kconfig | 12 + > drivers/net/wan/Makefile | 1 + > drivers/net/wan/fsl_qmc_hdlc.c | 422 +++++++++++++++++++++++++++++++++ > 3 files changed, 435 insertions(+) > create mode 100644 drivers/net/wan/fsl_qmc_hdlc.c >=20 > diff --git a/drivers/net/wan/Kconfig b/drivers/net/wan/Kconfig > index 7dda87756d3f..31ab2136cdf1 100644 > --- a/drivers/net/wan/Kconfig > +++ b/drivers/net/wan/Kconfig > @@ -197,6 +197,18 @@ config FARSYNC > =09 To compile this driver as a module, choose M here: the > =09 module will be called farsync. > =20 > +config FSL_QMC_HDLC > +=09tristate "Freescale QMC HDLC support" > +=09depends on HDLC > +=09depends on CPM_QMC > +=09help > +=09 HDLC support using the Freescale QUICC Multichannel Controller (QMC= ). > + > +=09 To compile this driver as a module, choose M here: the > +=09 module will be called fsl_qmc_hdlc. > + > +=09 If unsure, say N. > + > config FSL_UCC_HDLC > =09tristate "Freescale QUICC Engine HDLC support" > =09depends on HDLC > diff --git a/drivers/net/wan/Makefile b/drivers/net/wan/Makefile > index 8119b49d1da9..00e9b7ee1e01 100644 > --- a/drivers/net/wan/Makefile > +++ b/drivers/net/wan/Makefile > @@ -25,6 +25,7 @@ obj-$(CONFIG_WANXL)=09=09+=3D wanxl.o > obj-$(CONFIG_PCI200SYN)=09=09+=3D pci200syn.o > obj-$(CONFIG_PC300TOO)=09=09+=3D pc300too.o > obj-$(CONFIG_IXP4XX_HSS)=09+=3D ixp4xx_hss.o > +obj-$(CONFIG_FSL_QMC_HDLC)=09+=3D fsl_qmc_hdlc.o > obj-$(CONFIG_FSL_UCC_HDLC)=09+=3D fsl_ucc_hdlc.o > obj-$(CONFIG_SLIC_DS26522)=09+=3D slic_ds26522.o > =20 > diff --git a/drivers/net/wan/fsl_qmc_hdlc.c b/drivers/net/wan/fsl_qmc_hdl= c.c > new file mode 100644 > index 000000000000..e7b2b72a6050 > --- /dev/null > +++ b/drivers/net/wan/fsl_qmc_hdlc.c > @@ -0,0 +1,422 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Freescale QMC HDLC Device Driver > + * > + * Copyright 2023 CS GROUP France > + * > + * Author: Herve Codina > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +struct qmc_hdlc_desc { > +=09struct net_device *netdev; > +=09struct sk_buff *skb; /* NULL if the descriptor is not in use */ > +=09dma_addr_t dma_addr; > +=09size_t dma_size; > +}; > + > +struct qmc_hdlc { > +=09struct device *dev; > +=09struct qmc_chan *qmc_chan; > +=09struct net_device *netdev; > +=09bool is_crc32; > +=09spinlock_t tx_lock; /* Protect tx descriptors */ > +=09struct qmc_hdlc_desc tx_descs[8]; > +=09unsigned int tx_out; > +=09struct qmc_hdlc_desc rx_descs[4]; > +}; > + > +static inline struct qmc_hdlc *netdev_to_qmc_hdlc(struct net_device *net= dev) > +{ > +=09return dev_to_hdlc(netdev)->priv; > +} Please, no 'inline' function in c files. You could move this function and the struct definition into a new, local, header file. > +static int qmc_hdlc_recv_queue(struct qmc_hdlc *qmc_hdlc, struct qmc_hdl= c_desc *desc, size_t size); > + > +#define QMC_HDLC_RX_ERROR_FLAGS (QMC_RX_FLAG_HDLC_OVF | \ > +=09=09=09=09 QMC_RX_FLAG_HDLC_UNA | \ > +=09=09=09=09 QMC_RX_FLAG_HDLC_ABORT | \ > +=09=09=09=09 QMC_RX_FLAG_HDLC_CRC) > + > +static void qmc_hcld_recv_complete(void *context, size_t length, unsigne= d int flags) > +{ > +=09struct qmc_hdlc_desc *desc =3D context; > +=09struct net_device *netdev =3D desc->netdev; > +=09struct qmc_hdlc *qmc_hdlc =3D netdev_to_qmc_hdlc(netdev); > +=09int ret; Please, respect the reverse x-mas tree order for local variable definition. > +=09dma_unmap_single(qmc_hdlc->dev, desc->dma_addr, desc->dma_size, DMA_F= ROM_DEVICE); > + > +=09if (flags & QMC_HDLC_RX_ERROR_FLAGS) { > +=09=09netdev->stats.rx_errors++; > +=09=09if (flags & QMC_RX_FLAG_HDLC_OVF) /* Data overflow */ > +=09=09=09netdev->stats.rx_over_errors++; > +=09=09if (flags & QMC_RX_FLAG_HDLC_UNA) /* bits received not multiple of= 8 */ > +=09=09=09netdev->stats.rx_frame_errors++; > +=09=09if (flags & QMC_RX_FLAG_HDLC_ABORT) /* Received an abort sequence = */ > +=09=09=09netdev->stats.rx_frame_errors++; > +=09=09if (flags & QMC_RX_FLAG_HDLC_CRC) /* CRC error */ > +=09=09=09netdev->stats.rx_crc_errors++; > +=09=09kfree_skb(desc->skb); > +=09} else { > +=09=09netdev->stats.rx_packets++; > +=09=09netdev->stats.rx_bytes +=3D length; > + > +=09=09skb_put(desc->skb, length); > +=09=09desc->skb->protocol =3D hdlc_type_trans(desc->skb, netdev); > +=09=09netif_rx(desc->skb); > +=09} > + > +=09/* Re-queue a transfer using the same descriptor */ > +=09ret =3D qmc_hdlc_recv_queue(qmc_hdlc, desc, desc->dma_size); > +=09if (ret) { > +=09=09dev_err(qmc_hdlc->dev, "queue recv desc failed (%d)\n", ret); > +=09=09netdev->stats.rx_errors++; > +=09} > +} [...] > +static netdev_tx_t qmc_hdlc_xmit(struct sk_buff *skb, struct net_device = *netdev) > +{ > +=09struct qmc_hdlc *qmc_hdlc =3D netdev_to_qmc_hdlc(netdev); > +=09struct qmc_hdlc_desc *desc; > +=09unsigned long flags; > +=09int ret; > + > +=09spin_lock_irqsave(&qmc_hdlc->tx_lock, flags); > +=09desc =3D &qmc_hdlc->tx_descs[qmc_hdlc->tx_out]; > +=09if (WARN_ONCE(!desc->skb, "No tx descriptors available\n")) { > +=09=09/* Should never happen. > +=09=09 * Previous xmit should have already stopped the queue. > +=09=09 */ > +=09=09netif_stop_queue(netdev); > +=09=09spin_unlock_irqrestore(&qmc_hdlc->tx_lock, flags); > +=09=09return NETDEV_TX_BUSY; > +=09} > +=09spin_unlock_irqrestore(&qmc_hdlc->tx_lock, flags); > + > +=09desc->netdev =3D netdev; > +=09desc->dma_size =3D skb->len; > +=09desc->skb =3D skb; > +=09ret =3D qmc_hdlc_xmit_queue(qmc_hdlc, desc); > +=09if (ret) { > +=09=09desc->skb =3D NULL; /* Release the descriptor */ > +=09=09if (ret =3D=3D -EBUSY) { > +=09=09=09netif_stop_queue(netdev); > +=09=09=09return NETDEV_TX_BUSY; > +=09=09} > +=09=09dev_kfree_skb(skb); > +=09=09netdev->stats.tx_dropped++; > +=09=09return NETDEV_TX_OK; > +=09} > + > +=09qmc_hdlc->tx_out =3D (qmc_hdlc->tx_out + 1) % ARRAY_SIZE(qmc_hdlc->tx= _descs); > + > +=09spin_lock_irqsave(&qmc_hdlc->tx_lock, flags); > +=09if (qmc_hdlc->tx_descs[qmc_hdlc->tx_out].skb) > +=09=09netif_stop_queue(netdev); > +=09spin_unlock_irqrestore(&qmc_hdlc->tx_lock, flags); The locking schema is quite bad, as the drivers acquires and releases 3 locks for each tx packet. You could improve that using the qmc_chan- >tx_lock to protect the whole qmc_hdlc_xmit() function, factoring out a lockless variant of qmc_hdlc_xmit_queue(),=C2=A0and using it here. In general is quite bad that the existing infra does not allow leveraging NAPI. Have you considered expanding the QMC to accomodate such user? Cheers, Paolo