| // SPDX-License-Identifier: GPL-2.0-only |
| /* Copyright (c) 2014 Protonic Holland, |
| * David Jander |
| * Copyright (C) 2014-2017 Pengutronix, |
| * Marc Kleine-Budde <kernel@pengutronix.de> |
| */ |
| |
| #include <linux/can/dev.h> |
| #include <linux/can/rx-offload.h> |
| |
| struct can_rx_offload_cb { |
| u32 timestamp; |
| }; |
| |
| static inline struct can_rx_offload_cb * |
| can_rx_offload_get_cb(struct sk_buff *skb) |
| { |
| BUILD_BUG_ON(sizeof(struct can_rx_offload_cb) > sizeof(skb->cb)); |
| |
| return (struct can_rx_offload_cb *)skb->cb; |
| } |
| |
| static inline bool |
| can_rx_offload_le(struct can_rx_offload *offload, |
| unsigned int a, unsigned int b) |
| { |
| if (offload->inc) |
| return a <= b; |
| else |
| return a >= b; |
| } |
| |
| static inline unsigned int |
| can_rx_offload_inc(struct can_rx_offload *offload, unsigned int *val) |
| { |
| if (offload->inc) |
| return (*val)++; |
| else |
| return (*val)--; |
| } |
| |
| 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->len; |
| 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 inline void |
| __skb_queue_add_sort(struct sk_buff_head *head, struct sk_buff *new, |
| int (*compare)(struct sk_buff *a, struct sk_buff *b)) |
| { |
| struct sk_buff *pos, *insert = NULL; |
| |
| skb_queue_reverse_walk(head, pos) { |
| const struct can_rx_offload_cb *cb_pos, *cb_new; |
| |
| cb_pos = can_rx_offload_get_cb(pos); |
| cb_new = can_rx_offload_get_cb(new); |
| |
| netdev_dbg(new->dev, |
| "%s: pos=0x%08x, new=0x%08x, diff=%10d, queue_len=%d\n", |
| __func__, |
| cb_pos->timestamp, cb_new->timestamp, |
| cb_new->timestamp - cb_pos->timestamp, |
| skb_queue_len(head)); |
| |
| if (compare(pos, new) < 0) |
| continue; |
| insert = pos; |
| break; |
| } |
| if (!insert) |
| __skb_queue_head(head, new); |
| else |
| __skb_queue_after(head, insert, new); |
| } |
| |
| static int can_rx_offload_compare(struct sk_buff *a, struct sk_buff *b) |
| { |
| const struct can_rx_offload_cb *cb_a, *cb_b; |
| |
| cb_a = can_rx_offload_get_cb(a); |
| cb_b = can_rx_offload_get_cb(b); |
| |
| /* Subtract two u32 and return result as int, to keep |
| * difference steady around the u32 overflow. |
| */ |
| return cb_b->timestamp - cb_a->timestamp; |
| } |
| |
| /** |
| * can_rx_offload_offload_one() - Read one CAN frame from HW |
| * @offload: pointer to rx_offload context |
| * @n: number of mailbox to read |
| * |
| * The task of this function is to read a CAN frame from mailbox @n |
| * from the device and return the mailbox's content as a struct |
| * sk_buff. |
| * |
| * If the struct can_rx_offload::skb_queue exceeds the maximal queue |
| * length (struct can_rx_offload::skb_queue_len_max) or no skb can be |
| * allocated, the mailbox contents is discarded by reading it into an |
| * overflow buffer. This way the mailbox is marked as free by the |
| * driver. |
| * |
| * Return: A pointer to skb containing the CAN frame on success. |
| * |
| * NULL if the mailbox @n is empty. |
| * |
| * ERR_PTR() in case of an error |
| */ |
| static struct sk_buff * |
| can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n) |
| { |
| struct sk_buff *skb; |
| struct can_rx_offload_cb *cb; |
| bool drop = false; |
| u32 timestamp; |
| |
| /* If queue is full drop frame */ |
| if (unlikely(skb_queue_len(&offload->skb_queue) > |
| offload->skb_queue_len_max)) |
| drop = true; |
| |
| skb = offload->mailbox_read(offload, n, ×tamp, drop); |
| /* Mailbox was empty. */ |
| if (unlikely(!skb)) |
| return NULL; |
| |
| /* There was a problem reading the mailbox, propagate |
| * error value. |
| */ |
| if (IS_ERR(skb)) { |
| offload->dev->stats.rx_dropped++; |
| offload->dev->stats.rx_fifo_errors++; |
| |
| return skb; |
| } |
| |
| /* Mailbox was read. */ |
| cb = can_rx_offload_get_cb(skb); |
| cb->timestamp = timestamp; |
| |
| return skb; |
| } |
| |
| int can_rx_offload_irq_offload_timestamp(struct can_rx_offload *offload, |
| u64 pending) |
| { |
| struct sk_buff_head skb_queue; |
| unsigned int i; |
| |
| __skb_queue_head_init(&skb_queue); |
| |
| for (i = offload->mb_first; |
| can_rx_offload_le(offload, i, offload->mb_last); |
| can_rx_offload_inc(offload, &i)) { |
| struct sk_buff *skb; |
| |
| if (!(pending & BIT_ULL(i))) |
| continue; |
| |
| skb = can_rx_offload_offload_one(offload, i); |
| if (IS_ERR_OR_NULL(skb)) |
| continue; |
| |
| __skb_queue_add_sort(&skb_queue, skb, can_rx_offload_compare); |
| } |
| |
| if (!skb_queue_empty(&skb_queue)) { |
| unsigned long flags; |
| u32 queue_len; |
| |
| spin_lock_irqsave(&offload->skb_queue.lock, flags); |
| skb_queue_splice_tail(&skb_queue, &offload->skb_queue); |
| spin_unlock_irqrestore(&offload->skb_queue.lock, flags); |
| |
| queue_len = skb_queue_len(&offload->skb_queue); |
| if (queue_len > offload->skb_queue_len_max / 8) |
| netdev_dbg(offload->dev, "%s: queue_len=%d\n", |
| __func__, queue_len); |
| |
| can_rx_offload_schedule(offload); |
| } |
| |
| return skb_queue_len(&skb_queue); |
| } |
| EXPORT_SYMBOL_GPL(can_rx_offload_irq_offload_timestamp); |
| |
| int can_rx_offload_irq_offload_fifo(struct can_rx_offload *offload) |
| { |
| struct sk_buff *skb; |
| int received = 0; |
| |
| while (1) { |
| skb = can_rx_offload_offload_one(offload, 0); |
| if (IS_ERR(skb)) |
| continue; |
| if (!skb) |
| break; |
| |
| 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_queue_sorted(struct can_rx_offload *offload, |
| struct sk_buff *skb, u32 timestamp) |
| { |
| struct can_rx_offload_cb *cb; |
| unsigned long flags; |
| |
| if (skb_queue_len(&offload->skb_queue) > |
| offload->skb_queue_len_max) { |
| dev_kfree_skb_any(skb); |
| return -ENOBUFS; |
| } |
| |
| cb = can_rx_offload_get_cb(skb); |
| cb->timestamp = timestamp; |
| |
| spin_lock_irqsave(&offload->skb_queue.lock, flags); |
| __skb_queue_add_sort(&offload->skb_queue, skb, can_rx_offload_compare); |
| spin_unlock_irqrestore(&offload->skb_queue.lock, flags); |
| |
| can_rx_offload_schedule(offload); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(can_rx_offload_queue_sorted); |
| |
| unsigned int can_rx_offload_get_echo_skb(struct can_rx_offload *offload, |
| unsigned int idx, u32 timestamp, |
| unsigned int *frame_len_ptr) |
| { |
| struct net_device *dev = offload->dev; |
| struct net_device_stats *stats = &dev->stats; |
| struct sk_buff *skb; |
| u8 len; |
| int err; |
| |
| skb = __can_get_echo_skb(dev, idx, &len, frame_len_ptr); |
| if (!skb) |
| return 0; |
| |
| err = can_rx_offload_queue_sorted(offload, skb, timestamp); |
| if (err) { |
| stats->rx_errors++; |
| stats->tx_fifo_errors++; |
| } |
| |
| return len; |
| } |
| EXPORT_SYMBOL_GPL(can_rx_offload_get_echo_skb); |
| |
| int can_rx_offload_queue_tail(struct can_rx_offload *offload, |
| struct sk_buff *skb) |
| { |
| if (skb_queue_len(&offload->skb_queue) > |
| offload->skb_queue_len_max) { |
| dev_kfree_skb_any(skb); |
| return -ENOBUFS; |
| } |
| |
| skb_queue_tail(&offload->skb_queue, skb); |
| can_rx_offload_schedule(offload); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(can_rx_offload_queue_tail); |
| |
| 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); |
| |
| 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_timestamp(struct net_device *dev, |
| struct can_rx_offload *offload) |
| { |
| unsigned int weight; |
| |
| if (offload->mb_first > BITS_PER_LONG_LONG || |
| offload->mb_last > BITS_PER_LONG_LONG || !offload->mailbox_read) |
| return -EINVAL; |
| |
| if (offload->mb_first < offload->mb_last) { |
| offload->inc = true; |
| weight = offload->mb_last - offload->mb_first; |
| } else { |
| offload->inc = false; |
| weight = offload->mb_first - offload->mb_last; |
| } |
| |
| return can_rx_offload_init_queue(dev, offload, weight); |
| } |
| EXPORT_SYMBOL_GPL(can_rx_offload_add_timestamp); |
| |
| 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); |
| |
| int can_rx_offload_add_manual(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_manual); |
| |
| void can_rx_offload_enable(struct can_rx_offload *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); |