diff options
| -rw-r--r-- | drivers/net/can/Makefile | 3 | ||||
| -rw-r--r-- | drivers/net/can/rx-offload.c | 156 | ||||
| -rw-r--r-- | include/linux/can/rx-offload.h | 51 |
3 files changed, 209 insertions, 1 deletions
diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile index 7a85495dbb0c..0da4f2f5c7e3 100644 --- a/drivers/net/can/Makefile +++ b/drivers/net/can/Makefile @@ -6,7 +6,8 @@ obj-$(CONFIG_CAN_VCAN) += vcan.o obj-$(CONFIG_CAN_SLCAN) += slcan.o obj-$(CONFIG_CAN_DEV) += can-dev.o -can-dev-y := dev.o +can-dev-y += dev.o +can-dev-y += rx-offload.o can-dev-$(CONFIG_CAN_LEDS) += led.o diff --git a/drivers/net/can/rx-offload.c b/drivers/net/can/rx-offload.c new file mode 100644 index 000000000000..7267c61762c7 --- /dev/null +++ b/drivers/net/can/rx-offload.c @@ -0,0 +1,156 @@ +/* + * Copyright (c) 2014 David Jander, Protonic Holland + * Copyright (C) 2014-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the version 2 of the GNU General Public License + * as published by the Free Software Foundation + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/can/dev.h> +#include <linux/can/rx-offload.h> + +static int can_rx_offload_napi_poll(struct napi_struct *napi, int quota) +{ + struct can_rx_offload *offload = container_of(napi, struct can_rx_offload, napi); + struct net_device *dev = offload->dev; + struct net_device_stats *stats = &dev->stats; + struct sk_buff *skb; + int work_done = 0; + + while ((work_done < quota) && + (skb = skb_dequeue(&offload->skb_queue))) { + struct can_frame *cf = (struct can_frame *)skb->data; + + work_done++; + stats->rx_packets++; + stats->rx_bytes += cf->can_dlc; + netif_receive_skb(skb); + } + + if (work_done < quota) { + napi_complete_done(napi, work_done); + + /* Check if there was another interrupt */ + if (!skb_queue_empty(&offload->skb_queue)) + napi_reschedule(&offload->napi); + } + + can_led_event(offload->dev, CAN_LED_EVENT_RX); + + return work_done; +} + +static struct sk_buff *can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n) +{ + struct sk_buff *skb = NULL; + struct can_frame *cf; + int ret; + + /* If queue is full or skb not available, read to discard mailbox */ + if (likely(skb_queue_len(&offload->skb_queue) <= + offload->skb_queue_len_max)) + skb = alloc_can_skb(offload->dev, &cf); + + if (!skb) { + struct can_frame cf_overflow; + + ret = offload->mailbox_read(offload, &cf_overflow, n); + if (ret) + offload->dev->stats.rx_dropped++; + + return NULL; + } + + ret = offload->mailbox_read(offload, cf, n); + if (!ret) { + kfree_skb(skb); + return NULL; + } + + return skb; +} + +int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload) +{ + struct sk_buff *skb; + int received = 0; + + while ((skb = can_rx_offload_offload_one(offload, 0))) { + skb_queue_tail(&offload->skb_queue, skb); + received++; + } + + if (received) + can_rx_offload_schedule(offload); + + return received; +} +EXPORT_SYMBOL_GPL(can_rx_offload_irq_offload_fifo); + +int can_rx_offload_irq_queue_err_skb(struct can_rx_offload *offload, struct sk_buff *skb) +{ + if (skb_queue_len(&offload->skb_queue) > + offload->skb_queue_len_max) + return -ENOMEM; + + skb_queue_tail(&offload->skb_queue, skb); + can_rx_offload_schedule(offload); + + return 0; +} +EXPORT_SYMBOL_GPL(can_rx_offload_irq_queue_err_skb); + +static int can_rx_offload_init_queue(struct net_device *dev, struct can_rx_offload *offload, unsigned int weight) +{ + offload->dev = dev; + + /* Limit queue len to 4x the weight (rounted to next power of two) */ + offload->skb_queue_len_max = 2 << fls(weight); + offload->skb_queue_len_max *= 4; + skb_queue_head_init(&offload->skb_queue); + + can_rx_offload_reset(offload); + netif_napi_add(dev, &offload->napi, can_rx_offload_napi_poll, weight); + + dev_dbg(dev->dev.parent, "%s: skb_queue_len_max=%d\n", + __func__, offload->skb_queue_len_max); + + return 0; +} + +int can_rx_offload_add_fifo(struct net_device *dev, struct can_rx_offload *offload, unsigned int weight) +{ + if (!offload->mailbox_read) + return -EINVAL; + + return can_rx_offload_init_queue(dev, offload, weight); +} +EXPORT_SYMBOL_GPL(can_rx_offload_add_fifo); + +void can_rx_offload_enable(struct can_rx_offload *offload) +{ + can_rx_offload_reset(offload); + napi_enable(&offload->napi); +} +EXPORT_SYMBOL_GPL(can_rx_offload_enable); + +void can_rx_offload_del(struct can_rx_offload *offload) +{ + netif_napi_del(&offload->napi); + skb_queue_purge(&offload->skb_queue); +} +EXPORT_SYMBOL_GPL(can_rx_offload_del); + +void can_rx_offload_reset(struct can_rx_offload *offload) +{ +} +EXPORT_SYMBOL_GPL(can_rx_offload_reset); diff --git a/include/linux/can/rx-offload.h b/include/linux/can/rx-offload.h new file mode 100644 index 000000000000..cadfe9869600 --- /dev/null +++ b/include/linux/can/rx-offload.h @@ -0,0 +1,51 @@ +/* + * linux/can/rx-offload.h + * + * Copyright (c) 2014 David Jander, Protonic Holland + * Copyright (c) 2014-2017 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the version 2 of the GNU General Public License + * as published by the Free Software Foundation + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#ifndef _CAN_RX_OFFLOAD_H +#define _CAN_RX_OFFLOAD_H + +#include <linux/netdevice.h> +#include <linux/can.h> + +struct can_rx_offload { + struct net_device *dev; + + unsigned int (*mailbox_read)(struct can_rx_offload *offload, struct can_frame *cf, unsigned int mb); + + struct sk_buff_head skb_queue; + u32 skb_queue_len_max; + + struct napi_struct napi; +}; + +int can_rx_offload_add_fifo(struct net_device *dev, struct can_rx_offload *offload, unsigned int weight); +int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload); +int can_rx_offload_irq_queue_err_skb(struct can_rx_offload *offload, struct sk_buff *skb); +void can_rx_offload_reset(struct can_rx_offload *offload); +void can_rx_offload_del(struct can_rx_offload *offload); +void can_rx_offload_enable(struct can_rx_offload *offload); + +static inline void can_rx_offload_schedule(struct can_rx_offload *offload) +{ + napi_schedule(&offload->napi); +} + +static inline void can_rx_offload_disable(struct can_rx_offload *offload) +{ + napi_disable(&offload->napi); +} + +#endif /* !_CAN_RX_OFFLOAD_H */ |