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linux-next/include/linux/can/rx-offload.h

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treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 495 Based on 1 normalized pattern(s): 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 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 10 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Enrico Weigelt <info@metux.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.259525894@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-04 08:11:28 +00:00
/* SPDX-License-Identifier: GPL-2.0-only */
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
/*
* linux/can/rx-offload.h
*
* Copyright (c) 2014 David Jander, Protonic Holland
can: rx-offload: add can_rx_offload_get_echo_skb_queue_tail() Add can_rx_offload_get_echo_skb_queue_tail(). This function addds the echo skb at the end of rx-offload the queue. This is intended for devices without timestamp support. Link: https://lore.kernel.org/all/20230718-gs_usb-rx-offload-v2-2-716e542d14d5@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2023-07-03 16:18:19 +00:00
* Copyright (c) 2014-2017, 2023 Pengutronix, Marc Kleine-Budde <kernel@pengutronix.de>
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
*/
#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;
can: rx-offload: Prepare for CAN FD support The skbs for classic CAN and CAN FD frames are allocated with seperate functions: alloc_can_skb() and alloc_canfd_skb(). In order to support CAN FD frames via the rx-offload helper, the driver itself has to allocate the skb (depending whether it received a classic CAN or CAN FD frame), as the rx-offload helper cannot know which kind of CAN frame the driver has received. This patch moves the allocation of the skb into the struct can_rx_offload::mailbox_read callbacks of the the flexcan and ti_hecc driver and adjusts the rx-offload helper accordingly. Signed-off-by: Joakim Zhang <qiangqing.zhang@nxp.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2019-07-12 08:02:38 +00:00
struct sk_buff *(*mailbox_read)(struct can_rx_offload *offload,
unsigned int mb, u32 *timestamp,
bool drop);
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 sk_buff_head skb_queue;
can: rx-offload: add skb queue for use during ISR Adding a skb to the skb_queue in rx-offload requires to take a lock. This commit avoids this by adding an unlocked skb queue that is appended at the end of the ISR. Having one lock at the end of the ISR should be OK as the HW is empty, not about to overflow. Link: https://lore.kernel.org/r/20210724204745.736053-2-mkl@pengutronix.de Tested-by: Oleksij Rempel <o.rempel@pengutronix.de> Co-developed-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be> Signed-off-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2019-10-09 04:41:08 +00:00
struct sk_buff_head skb_irq_queue;
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
u32 skb_queue_len_max;
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
unsigned int mb_first;
unsigned int mb_last;
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 napi_struct napi;
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
bool inc;
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: dev: avoid long lines This patch fixes long lines in the generic CAN device infrastructure. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2019-08-27 11:53:18 +00:00
int can_rx_offload_add_timestamp(struct net_device *dev,
struct can_rx_offload *offload);
int can_rx_offload_add_fifo(struct net_device *dev,
struct can_rx_offload *offload,
unsigned int weight);
can: rx-offload: can_rx_offload_add_manual(): add new initialization function This patch adds a new initialization function: can_rx_offload_add_manual() It should be used to add support rx-offload to a driver, if the callback mechanism should not be used. Use e.g. can_rx_offload_queue_sorted() to queue skbs into rx-offload. Link: https://lore.kernel.org/r/20200915223527.1417033-33-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2020-09-15 22:35:22 +00:00
int can_rx_offload_add_manual(struct net_device *dev,
struct can_rx_offload *offload,
unsigned int weight);
can: dev: avoid long lines This patch fixes long lines in the generic CAN device infrastructure. Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2019-08-27 11:53:18 +00:00
int can_rx_offload_irq_offload_timestamp(struct can_rx_offload *offload,
u64 reg);
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);
can: rx-offload: rename can_rx_offload_queue_sorted() -> can_rx_offload_queue_timestamp() This patch renames the function can_rx_offload_queue_sorted() to can_rx_offload_queue_timestamp(). This better describes what the function does, it adds a newly RX'ed skb to the sorted queue by its timestamp. Link: https://lore.kernel.org/all/20220417194327.2699059-1-mkl@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2022-03-14 22:09:10 +00:00
int can_rx_offload_queue_timestamp(struct can_rx_offload *offload,
struct sk_buff *skb, u32 timestamp);
can: rx-offload: rename rx_offload_get_echo_skb() -> can_rx_offload_get_echo_skb_queue_timestamp() Rename the rx_offload_get_echo_skb() function to can_rx_offload_get_echo_skb_queue_timestamp(), since it inserts the echo skb into the rx-offload queue sorted by timestamp. This is a preparation for adding can_rx_offload_get_echo_skb_queue_tail(), which adds the echo skb to the end of the queue. This is intended for devices that do not support timestamps. Link: https://lore.kernel.org/all/20230718-gs_usb-rx-offload-v2-1-716e542d14d5@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2023-06-02 07:36:38 +00:00
unsigned int can_rx_offload_get_echo_skb_queue_timestamp(struct can_rx_offload *offload,
unsigned int idx, u32 timestamp,
unsigned int *frame_len_ptr);
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 can_rx_offload_get_echo_skb_queue_tail() Add can_rx_offload_get_echo_skb_queue_tail(). This function addds the echo skb at the end of rx-offload the queue. This is intended for devices without timestamp support. Link: https://lore.kernel.org/all/20230718-gs_usb-rx-offload-v2-2-716e542d14d5@pengutronix.de Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2023-07-03 16:18:19 +00:00
unsigned int can_rx_offload_get_echo_skb_queue_tail(struct can_rx_offload *offload,
unsigned int idx,
unsigned int *frame_len_ptr);
can: rx-offload: add skb queue for use during ISR Adding a skb to the skb_queue in rx-offload requires to take a lock. This commit avoids this by adding an unlocked skb queue that is appended at the end of the ISR. Having one lock at the end of the ISR should be OK as the HW is empty, not about to overflow. Link: https://lore.kernel.org/r/20210724204745.736053-2-mkl@pengutronix.de Tested-by: Oleksij Rempel <o.rempel@pengutronix.de> Co-developed-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be> Signed-off-by: Kurt Van Dijck <dev.kurt@vandijck-laurijssen.be> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2019-10-09 04:41:08 +00:00
void can_rx_offload_irq_finish(struct can_rx_offload *offload);
can: rx-offload: can_rx_offload_threaded_irq_finish(): add new function to be called from threaded interrupt After reading all CAN frames from the controller in the IRQ handler and storing them into a skb_queue, the driver calls napi_schedule(). In the napi poll function the skb from the skb_queue are then pushed into the networking stack. However if napi_schedule() is called from a threaded IRQ handler this triggers the following error: | NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #08!!! To avoid this, create a new rx-offload function (can_rx_offload_threaded_irq_finish()) with a call to local_bh_disable()/local_bh_enable() around the napi_schedule() call. Convert all drivers that call can_rx_offload_irq_finish() from threaded IRQ context to can_rx_offload_threaded_irq_finish(). Link: https://lore.kernel.org/r/20210724204745.736053-4-mkl@pengutronix.de Suggested-by: Daniel Glöckner <dg@emlix.com> Tested-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
2021-05-10 20:51:39 +00:00
void can_rx_offload_threaded_irq_finish(struct can_rx_offload *offload);
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
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_disable(struct can_rx_offload *offload)
{
napi_disable(&offload->napi);
}
#endif /* !_CAN_RX_OFFLOAD_H */
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