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/*
* 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);
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