v4.19.13 snapshot.
diff --git a/drivers/net/can/rx-offload.c b/drivers/net/can/rx-offload.c
new file mode 100644
index 0000000..727691d
--- /dev/null
+++ b/drivers/net/can/rx-offload.c
@@ -0,0 +1,336 @@
+/*
+ * 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>
+
+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->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 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 = (struct sk_buff *)head;
+
+ 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;
+ }
+
+ __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);
+
+ /* Substract two u32 and return result as int, to keep
+ * difference steady around the u32 overflow.
+ */
+ return cb_b->timestamp - cb_a->timestamp;
+}
+
+static struct sk_buff *can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n)
+{
+ struct sk_buff *skb = NULL;
+ struct can_rx_offload_cb *cb;
+ 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;
+ u32 timestamp;
+
+ ret = offload->mailbox_read(offload, &cf_overflow,
+ ×tamp, n);
+ if (ret)
+ offload->dev->stats.rx_dropped++;
+
+ return NULL;
+ }
+
+ cb = can_rx_offload_get_cb(skb);
+ ret = offload->mailbox_read(offload, cf, &cb->timestamp, n);
+ if (!ret) {
+ kfree_skb(skb);
+ return NULL;
+ }
+
+ 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 (!skb)
+ break;
+
+ __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);
+
+ if ((queue_len = skb_queue_len(&offload->skb_queue)) >
+ (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 ((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_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)
+ return -ENOMEM;
+
+ 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)
+{
+ 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);
+ 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)
+ return -ENOMEM;
+
+ 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);
+
+ 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_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);
+
+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);