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linux/drivers/net/can/rx-offload.c

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can: rx-offload: Add support for HW fifo based irq offloading Some CAN controllers have a usable FIFO already but can still benefit from off-loading the CAN controller FIFO. The CAN frames of the FIFO are read and put into a skb queue during interrupt and then transmitted in a NAPI context. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-10 15:30:10 +00:00
/*
* 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>
can: rx-offload: Add support for timestamp based irq offloading Some CAN controllers don't implement a FIFO in hardware, but fill their mailboxes in a particular order (from lowest to highest or highest to lowest). This makes problems to read the frames in the correct order from the hardware, as new frames might be filled into just read (low) mailboxes. This gets worse, when following new frames are received into not read (higher) mailboxes. On the bright side some these CAN controllers put a timestamp on each received CAN frame. This patch adds support to offload CAN frames in interrupt context, order them by timestamp and then transmitted in a NAPI context. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-09-23 13:28:21 +00:00
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)--;
}
can: rx-offload: Add support for HW fifo based irq offloading Some CAN controllers have a usable FIFO already but can still benefit from off-loading the CAN controller FIFO. The CAN frames of the FIFO are read and put into a skb queue during interrupt and then transmitted in a NAPI context. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-10 15:30:10 +00:00
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;
}
can: rx-offload: Add support for timestamp based irq offloading Some CAN controllers don't implement a FIFO in hardware, but fill their mailboxes in a particular order (from lowest to highest or highest to lowest). This makes problems to read the frames in the correct order from the hardware, as new frames might be filled into just read (low) mailboxes. This gets worse, when following new frames are received into not read (higher) mailboxes. On the bright side some these CAN controllers put a timestamp on each received CAN frame. This patch adds support to offload CAN frames in interrupt context, order them by timestamp and then transmitted in a NAPI context. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-09-23 13:28:21 +00:00
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))
{
can: Remove SKB list assumptions in rx-offload.c Eliminate code which assumes that SKBs and skb_queue_head objects can be cast to eachother during list processing. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-22 23:43:34 +00:00
struct sk_buff *pos, *insert = NULL;
can: rx-offload: Add support for timestamp based irq offloading Some CAN controllers don't implement a FIFO in hardware, but fill their mailboxes in a particular order (from lowest to highest or highest to lowest). This makes problems to read the frames in the correct order from the hardware, as new frames might be filled into just read (low) mailboxes. This gets worse, when following new frames are received into not read (higher) mailboxes. On the bright side some these CAN controllers put a timestamp on each received CAN frame. This patch adds support to offload CAN frames in interrupt context, order them by timestamp and then transmitted in a NAPI context. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-09-23 13:28:21 +00:00
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;
}
can: Remove SKB list assumptions in rx-offload.c Eliminate code which assumes that SKBs and skb_queue_head objects can be cast to eachother during list processing. Signed-off-by: David S. Miller <davem@davemloft.net>
2018-08-22 23:43:34 +00:00
if (!insert)
__skb_queue_head(head, new);
else
__skb_queue_after(head, insert, new);
can: rx-offload: Add support for timestamp based irq offloading Some CAN controllers don't implement a FIFO in hardware, but fill their mailboxes in a particular order (from lowest to highest or highest to lowest). This makes problems to read the frames in the correct order from the hardware, as new frames might be filled into just read (low) mailboxes. This gets worse, when following new frames are received into not read (higher) mailboxes. On the bright side some these CAN controllers put a timestamp on each received CAN frame. This patch adds support to offload CAN frames in interrupt context, order them by timestamp and then transmitted in a NAPI context. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-09-23 13:28:21 +00:00
}
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;
}
can: rx-offload: Add support for HW fifo based irq offloading Some CAN controllers have a usable FIFO already but can still benefit from off-loading the CAN controller FIFO. The CAN frames of the FIFO are read and put into a skb queue during interrupt and then transmitted in a NAPI context. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-10 15:30:10 +00:00
static struct sk_buff *can_rx_offload_offload_one(struct can_rx_offload *offload, unsigned int n)
{
struct sk_buff *skb = NULL;
can: rx-offload: Add support for timestamp based irq offloading Some CAN controllers don't implement a FIFO in hardware, but fill their mailboxes in a particular order (from lowest to highest or highest to lowest). This makes problems to read the frames in the correct order from the hardware, as new frames might be filled into just read (low) mailboxes. This gets worse, when following new frames are received into not read (higher) mailboxes. On the bright side some these CAN controllers put a timestamp on each received CAN frame. This patch adds support to offload CAN frames in interrupt context, order them by timestamp and then transmitted in a NAPI context. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-09-23 13:28:21 +00:00
struct can_rx_offload_cb *cb;
can: rx-offload: Add support for HW fifo based irq offloading Some CAN controllers have a usable FIFO already but can still benefit from off-loading the CAN controller FIFO. The CAN frames of the FIFO are read and put into a skb queue during interrupt and then transmitted in a NAPI context. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-10 15:30:10 +00:00
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;
can: rx-offload: Add support for timestamp based irq offloading Some CAN controllers don't implement a FIFO in hardware, but fill their mailboxes in a particular order (from lowest to highest or highest to lowest). This makes problems to read the frames in the correct order from the hardware, as new frames might be filled into just read (low) mailboxes. This gets worse, when following new frames are received into not read (higher) mailboxes. On the bright side some these CAN controllers put a timestamp on each received CAN frame. This patch adds support to offload CAN frames in interrupt context, order them by timestamp and then transmitted in a NAPI context. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-09-23 13:28:21 +00:00
u32 timestamp;
can: rx-offload: Add support for HW fifo based irq offloading Some CAN controllers have a usable FIFO already but can still benefit from off-loading the CAN controller FIFO. The CAN frames of the FIFO are read and put into a skb queue during interrupt and then transmitted in a NAPI context. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-10 15:30:10 +00:00
can: rx-offload: Add support for timestamp based irq offloading Some CAN controllers don't implement a FIFO in hardware, but fill their mailboxes in a particular order (from lowest to highest or highest to lowest). This makes problems to read the frames in the correct order from the hardware, as new frames might be filled into just read (low) mailboxes. This gets worse, when following new frames are received into not read (higher) mailboxes. On the bright side some these CAN controllers put a timestamp on each received CAN frame. This patch adds support to offload CAN frames in interrupt context, order them by timestamp and then transmitted in a NAPI context. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-09-23 13:28:21 +00:00
ret = offload->mailbox_read(offload, &cf_overflow,
&timestamp, n);
can: rx-offload: Add support for HW fifo based irq offloading Some CAN controllers have a usable FIFO already but can still benefit from off-loading the CAN controller FIFO. The CAN frames of the FIFO are read and put into a skb queue during interrupt and then transmitted in a NAPI context. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-10 15:30:10 +00:00
if (ret)
offload->dev->stats.rx_dropped++;
return NULL;
}
can: rx-offload: Add support for timestamp based irq offloading Some CAN controllers don't implement a FIFO in hardware, but fill their mailboxes in a particular order (from lowest to highest or highest to lowest). This makes problems to read the frames in the correct order from the hardware, as new frames might be filled into just read (low) mailboxes. This gets worse, when following new frames are received into not read (higher) mailboxes. On the bright side some these CAN controllers put a timestamp on each received CAN frame. This patch adds support to offload CAN frames in interrupt context, order them by timestamp and then transmitted in a NAPI context. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-09-23 13:28:21 +00:00
cb = can_rx_offload_get_cb(skb);
ret = offload->mailbox_read(offload, cf, &cb->timestamp, n);
can: rx-offload: Add support for HW fifo based irq offloading Some CAN controllers have a usable FIFO already but can still benefit from off-loading the CAN controller FIFO. The CAN frames of the FIFO are read and put into a skb queue during interrupt and then transmitted in a NAPI context. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-10 15:30:10 +00:00
if (!ret) {
kfree_skb(skb);
return NULL;
}
return skb;
}
can: rx-offload: Add support for timestamp based irq offloading Some CAN controllers don't implement a FIFO in hardware, but fill their mailboxes in a particular order (from lowest to highest or highest to lowest). This makes problems to read the frames in the correct order from the hardware, as new frames might be filled into just read (low) mailboxes. This gets worse, when following new frames are received into not read (higher) mailboxes. On the bright side some these CAN controllers put a timestamp on each received CAN frame. This patch adds support to offload CAN frames in interrupt context, order them by timestamp and then transmitted in a NAPI context. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-09-23 13:28:21 +00:00
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);
can: rx-offload: Add support for HW fifo based irq offloading Some CAN controllers have a usable FIFO already but can still benefit from off-loading the CAN controller FIFO. The CAN frames of the FIFO are read and put into a skb queue during interrupt and then transmitted in a NAPI context. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-10 15:30:10 +00:00
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);
can: rx-offload: introduce can_rx_offload_get_echo_skb() and can_rx_offload_queue_sorted() functions Current CAN framework can't guarantee proper/chronological order of RX and TX-ECHO messages. To make this possible, drivers should use this functions instead of can_get_echo_skb(). Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-09-18 09:40:38 +00:00
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);
can: rx-offload: rename can_rx_offload_irq_queue_err_skb() to can_rx_offload_queue_tail() This function has nothing todo with error. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-09-18 09:40:40 +00:00
int can_rx_offload_queue_tail(struct can_rx_offload *offload,
struct sk_buff *skb)
can: rx-offload: Add support for HW fifo based irq offloading Some CAN controllers have a usable FIFO already but can still benefit from off-loading the CAN controller FIFO. The CAN frames of the FIFO are read and put into a skb queue during interrupt and then transmitted in a NAPI context. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-10 15:30:10 +00:00
{
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;
}
can: rx-offload: rename can_rx_offload_irq_queue_err_skb() to can_rx_offload_queue_tail() This function has nothing todo with error. Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Cc: linux-stable <stable@vger.kernel.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2018-09-18 09:40:40 +00:00
EXPORT_SYMBOL_GPL(can_rx_offload_queue_tail);
can: rx-offload: Add support for HW fifo based irq offloading Some CAN controllers have a usable FIFO already but can still benefit from off-loading the CAN controller FIFO. The CAN frames of the FIFO are read and put into a skb queue during interrupt and then transmitted in a NAPI context. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-10 15:30:10 +00:00
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;
}
can: rx-offload: Add support for timestamp based irq offloading Some CAN controllers don't implement a FIFO in hardware, but fill their mailboxes in a particular order (from lowest to highest or highest to lowest). This makes problems to read the frames in the correct order from the hardware, as new frames might be filled into just read (low) mailboxes. This gets worse, when following new frames are received into not read (higher) mailboxes. On the bright side some these CAN controllers put a timestamp on each received CAN frame. This patch adds support to offload CAN frames in interrupt context, order them by timestamp and then transmitted in a NAPI context. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-09-23 13:28:21 +00:00
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;
}
can: rx-offload: can_rx_offload_add_timestamp: remove duplicate semicolon at return statement This patch removes the duplicate semicolon at the end of the return statement. Suggested-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2017-12-06 13:19:08 +00:00
return can_rx_offload_init_queue(dev, offload, weight);
can: rx-offload: Add support for timestamp based irq offloading Some CAN controllers don't implement a FIFO in hardware, but fill their mailboxes in a particular order (from lowest to highest or highest to lowest). This makes problems to read the frames in the correct order from the hardware, as new frames might be filled into just read (low) mailboxes. This gets worse, when following new frames are received into not read (higher) mailboxes. On the bright side some these CAN controllers put a timestamp on each received CAN frame. This patch adds support to offload CAN frames in interrupt context, order them by timestamp and then transmitted in a NAPI context. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-09-23 13:28:21 +00:00
}
EXPORT_SYMBOL_GPL(can_rx_offload_add_timestamp);
can: rx-offload: Add support for HW fifo based irq offloading Some CAN controllers have a usable FIFO already but can still benefit from off-loading the CAN controller FIFO. The CAN frames of the FIFO are read and put into a skb queue during interrupt and then transmitted in a NAPI context. Signed-off-by: David Jander <david@protonic.nl> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2014-10-10 15:30:10 +00:00
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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