Merge tag 'linux-can-next-for-6.5-20230622' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next

Marc Kleine-Budde says:

====================
pull-request: can-next 2023-06-22

The first patch is by Carsten Schmidt, targets the kvaser_usb driver
and adds len8_dlc support.

Marcel Hellwig's patch for the xilinx_can driver adds support for CAN
transceivers via the PHY framework.

Frank Jungclaus contributes 6+2 patches for the esd_usb driver in
preparation for the upcoming CAN-USB/3 support.

The 2 patches by Miquel Raynal for the sja1000 driver work around
overruns stalls on the Renesas SoCs.

The next 3 patches are by me and fix the coding style in the
rx-offload helper and in the m_can and ti_hecc driver.

Vincent Mailhol contributes 3 patches to fix and update the
calculation of the length of CAN frames on the wire.

Oliver Hartkopp's patch moves the CAN_RAW_FILTER_MAX definition into
the correct header.

The remaining 14 patches are by Jimmy Assarsson, target the
kvaser_pciefd driver and bring various updates and improvements.

* tag 'linux-can-next-for-6.5-20230622' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can-next: (33 commits)
  can: kvaser_pciefd: Use TX FIFO size read from CAN controller
  can: kvaser_pciefd: Refactor code
  can: kvaser_pciefd: Add len8_dlc support
  can: kvaser_pciefd: Use FIELD_{GET,PREP} and GENMASK where appropriate
  can: kvaser_pciefd: Sort register definitions
  can: kvaser_pciefd: Change return type for kvaser_pciefd_{receive,transmit,set_tx}_irq()
  can: kvaser_pciefd: Rename device ID defines
  can: kvaser_pciefd: Sort includes in alphabetic order
  can: kvaser_pciefd: Remove SPI flash parameter read functionality
  can: uapi: move CAN_RAW_FILTER_MAX definition to raw.h
  can: kvaser_pciefd: Define unsigned constants with type suffix 'U'
  can: kvaser_pciefd: Set hardware timestamp on transmitted packets
  can: kvaser_pciefd: Add function to set skb hwtstamps
  can: kvaser_pciefd: Remove handler for unused KVASER_PCIEFD_PACK_TYPE_EFRAME_ACK
  can: kvaser_pciefd: Remove useless write to interrupt register
  can: length: refactor frame lengths definition to add size in bits
  can: length: fix bitstuffing count
  can: length: fix description of the RRS field
  can: m_can: fix coding style
  can: ti_hecc: fix coding style
  ...
====================

Link: https://lore.kernel.org/r/20230622082658.571150-1-mkl@pengutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

3 files changed, 216 insertions, 86 deletions

diff --git a/include/linux/can/length.h b/include/linux/can/length.h
index 69336549d24f..abc978b38f79 100644
--- a/include/linux/can/length.h
+++ b/include/linux/can/length.h
@@ -1,129 +1,258 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 /* Copyright (C) 2020 Oliver Hartkopp <socketcan@hartkopp.net>
  * Copyright (C) 2020 Marc Kleine-Budde <kernel@pengutronix.de>
+ * Copyright (C) 2020, 2023 Vincent Mailhol <mailhol.vincent@wanadoo.fr>
  */
 
 #ifndef _CAN_LENGTH_H
 #define _CAN_LENGTH_H
 
+#include <linux/bits.h>
 #include <linux/can.h>
 #include <linux/can/netlink.h>
+#include <linux/math.h>
 
 /*
- * Size of a Classical CAN Standard Frame
+ * Size of a Classical CAN Standard Frame header in bits
  *
- * Name of Field			Bits
+ * Name of Field				Bits
  * ---------------------------------------------------------
- * Start-of-frame			1
- * Identifier				11
- * Remote transmission request (RTR)	1
- * Identifier extension bit (IDE)	1
- * Reserved bit (r0)			1
- * Data length code (DLC)		4
- * Data field				0...64
- * CRC					15
- * CRC delimiter			1
- * ACK slot				1
- * ACK delimiter			1
- * End-of-frame (EOF)			7
- * Inter frame spacing			3
+ * Start Of Frame (SOF)				1
+ * Arbitration field:
+ *	base ID					11
+ *	Remote Transmission Request (RTR)	1
+ * Control field:
+ *	IDentifier Extension bit (IDE)		1
+ *	FD Format indicator (FDF)		1
+ *	Data Length Code (DLC)			4
+ *
+ * including all fields preceding the data field, ignoring bitstuffing
+ */
+#define CAN_FRAME_HEADER_SFF_BITS 19
+
+/*
+ * Size of a Classical CAN Extended Frame header in bits
  *
- * rounded up and ignoring bitstuffing
+ * Name of Field				Bits
+ * ---------------------------------------------------------
+ * Start Of Frame (SOF)				1
+ * Arbitration field:
+ *	base ID					11
+ *	Substitute Remote Request (SRR)		1
+ *	IDentifier Extension bit (IDE)		1
+ *	ID extension				18
+ *	Remote Transmission Request (RTR)	1
+ * Control field:
+ *	FD Format indicator (FDF)		1
+ *	Reserved bit (r0)			1
+ *	Data length code (DLC)			4
+ *
+ * including all fields preceding the data field, ignoring bitstuffing
  */
-#define CAN_FRAME_OVERHEAD_SFF DIV_ROUND_UP(47, 8)
+#define CAN_FRAME_HEADER_EFF_BITS 39
 
 /*
- * Size of a Classical CAN Extended Frame
+ * Size of a CAN-FD Standard Frame in bits
+ *
+ * Name of Field				Bits
+ * ---------------------------------------------------------
+ * Start Of Frame (SOF)				1
+ * Arbitration field:
+ *	base ID					11
+ *	Remote Request Substitution (RRS)	1
+ * Control field:
+ *	IDentifier Extension bit (IDE)		1
+ *	FD Format indicator (FDF)		1
+ *	Reserved bit (res)			1
+ *	Bit Rate Switch (BRS)			1
+ *	Error Status Indicator (ESI)		1
+ *	Data length code (DLC)			4
+ *
+ * including all fields preceding the data field, ignoring bitstuffing
+ */
+#define CANFD_FRAME_HEADER_SFF_BITS 22
+
+/*
+ * Size of a CAN-FD Extended Frame in bits
+ *
+ * Name of Field				Bits
+ * ---------------------------------------------------------
+ * Start Of Frame (SOF)				1
+ * Arbitration field:
+ *	base ID					11
+ *	Substitute Remote Request (SRR)		1
+ *	IDentifier Extension bit (IDE)		1
+ *	ID extension				18
+ *	Remote Request Substitution (RRS)	1
+ * Control field:
+ *	FD Format indicator (FDF)		1
+ *	Reserved bit (res)			1
+ *	Bit Rate Switch (BRS)			1
+ *	Error Status Indicator (ESI)		1
+ *	Data length code (DLC)			4
+ *
+ * including all fields preceding the data field, ignoring bitstuffing
+ */
+#define CANFD_FRAME_HEADER_EFF_BITS 41
+
+/*
+ * Size of a CAN CRC Field in bits
  *
  * Name of Field			Bits
  * ---------------------------------------------------------
- * Start-of-frame			1
- * Identifier A				11
- * Substitute remote request (SRR)	1
- * Identifier extension bit (IDE)	1
- * Identifier B				18
- * Remote transmission request (RTR)	1
- * Reserved bits (r1, r0)		2
- * Data length code (DLC)		4
- * Data field				0...64
- * CRC					15
- * CRC delimiter			1
- * ACK slot				1
- * ACK delimiter			1
- * End-of-frame (EOF)			7
- * Inter frame spacing			3
+ * CRC sequence (CRC15)			15
+ * CRC Delimiter			1
+ *
+ * ignoring bitstuffing
+ */
+#define CAN_FRAME_CRC_FIELD_BITS 16
+
+/*
+ * Size of a CAN-FD CRC17 Field in bits (length: 0..16)
  *
- * rounded up and ignoring bitstuffing
+ * Name of Field			Bits
+ * ---------------------------------------------------------
+ * Stuff Count				4
+ * CRC Sequence (CRC17)			17
+ * CRC Delimiter			1
+ * Fixed stuff bits			6
  */
-#define CAN_FRAME_OVERHEAD_EFF DIV_ROUND_UP(67, 8)
+#define CANFD_FRAME_CRC17_FIELD_BITS 28
 
 /*
- * Size of a CAN-FD Standard Frame
+ * Size of a CAN-FD CRC21 Field in bits (length: 20..64)
  *
  * Name of Field			Bits
  * ---------------------------------------------------------
- * Start-of-frame			1
- * Identifier				11
- * Reserved bit (r1)			1
- * Identifier extension bit (IDE)	1
- * Flexible data rate format (FDF)	1
- * Reserved bit (r0)			1
- * Bit Rate Switch (BRS)		1
- * Error Status Indicator (ESI)		1
- * Data length code (DLC)		4
- * Data field				0...512
- * Stuff Bit Count (SBC)		0...16: 4 20...64:5
- * CRC					0...16: 17 20...64:21
- * CRC delimiter (CD)			1
- * ACK slot (AS)			1
- * ACK delimiter (AD)			1
- * End-of-frame (EOF)			7
- * Inter frame spacing			3
- *
- * assuming CRC21, rounded up and ignoring bitstuffing
- */
-#define CANFD_FRAME_OVERHEAD_SFF DIV_ROUND_UP(61, 8)
+ * Stuff Count				4
+ * CRC sequence (CRC21)			21
+ * CRC Delimiter			1
+ * Fixed stuff bits			7
+ */
+#define CANFD_FRAME_CRC21_FIELD_BITS 33
 
 /*
- * Size of a CAN-FD Extended Frame
+ * Size of a CAN(-FD) Frame footer in bits
  *
  * Name of Field			Bits
  * ---------------------------------------------------------
- * Start-of-frame			1
- * Identifier A				11
- * Substitute remote request (SRR)	1
- * Identifier extension bit (IDE)	1
- * Identifier B				18
- * Reserved bit (r1)			1
- * Flexible data rate format (FDF)	1
- * Reserved bit (r0)			1
- * Bit Rate Switch (BRS)		1
- * Error Status Indicator (ESI)		1
- * Data length code (DLC)		4
- * Data field				0...512
- * Stuff Bit Count (SBC)		0...16: 4 20...64:5
- * CRC					0...16: 17 20...64:21
- * CRC delimiter (CD)			1
- * ACK slot (AS)			1
- * ACK delimiter (AD)			1
- * End-of-frame (EOF)			7
- * Inter frame spacing			3
- *
- * assuming CRC21, rounded up and ignoring bitstuffing
- */
-#define CANFD_FRAME_OVERHEAD_EFF DIV_ROUND_UP(80, 8)
+ * ACK slot				1
+ * ACK delimiter			1
+ * End Of Frame (EOF)			7
+ *
+ * including all fields following the CRC field
+ */
+#define CAN_FRAME_FOOTER_BITS 9
+
+/*
+ * First part of the Inter Frame Space
+ * (a.k.a. IMF - intermission field)
+ */
+#define CAN_INTERMISSION_BITS 3
+
+/**
+ * can_bitstuffing_len() - Calculate the maximum length with bitstuffing
+ * @destuffed_len: length of a destuffed bit stream
+ *
+ * The worst bit stuffing case is a sequence in which dominant and
+ * recessive bits alternate every four bits:
+ *
+ *   Destuffed: 1 1111  0000  1111  0000  1111
+ *   Stuffed:   1 1111o 0000i 1111o 0000i 1111o
+ *
+ * Nomenclature
+ *
+ *  - "0": dominant bit
+ *  - "o": dominant stuff bit
+ *  - "1": recessive bit
+ *  - "i": recessive stuff bit
+ *
+ * Aside from the first bit, one stuff bit is added every four bits.
+ *
+ * Return: length of the stuffed bit stream in the worst case scenario.
+ */
+#define can_bitstuffing_len(destuffed_len)			\
+	(destuffed_len + (destuffed_len - 1) / 4)
+
+#define __can_bitstuffing_len(bitstuffing, destuffed_len)	\
+	(bitstuffing ? can_bitstuffing_len(destuffed_len) :	\
+		       destuffed_len)
+
+#define __can_cc_frame_bits(is_eff, bitstuffing,		\
+			    intermission, data_len)		\
+(								\
+	__can_bitstuffing_len(bitstuffing,			\
+		(is_eff ? CAN_FRAME_HEADER_EFF_BITS :		\
+			  CAN_FRAME_HEADER_SFF_BITS) +		\
+		(data_len) * BITS_PER_BYTE +			\
+		CAN_FRAME_CRC_FIELD_BITS) +			\
+	CAN_FRAME_FOOTER_BITS +					\
+	(intermission ? CAN_INTERMISSION_BITS : 0)		\
+)
+
+#define __can_fd_frame_bits(is_eff, bitstuffing,		\
+			    intermission, data_len)		\
+(								\
+	__can_bitstuffing_len(bitstuffing,			\
+		(is_eff ? CANFD_FRAME_HEADER_EFF_BITS :		\
+			  CANFD_FRAME_HEADER_SFF_BITS) +	\
+		(data_len) * BITS_PER_BYTE) +			\
+	((data_len) <= 16 ?					\
+		CANFD_FRAME_CRC17_FIELD_BITS :			\
+		CANFD_FRAME_CRC21_FIELD_BITS) +			\
+	CAN_FRAME_FOOTER_BITS +					\
+	(intermission ? CAN_INTERMISSION_BITS : 0)		\
+)
+
+/**
+ * can_frame_bits() - Calculate the number of bits on the wire in a
+ *	CAN frame
+ * @is_fd: true: CAN-FD frame; false: Classical CAN frame.
+ * @is_eff: true: Extended frame; false: Standard frame.
+ * @bitstuffing: true: calculate the bitstuffing worst case; false:
+ *	calculate the bitstuffing best case (no dynamic
+ *	bitstuffing). CAN-FD's fixed stuff bits are always included.
+ * @intermission: if and only if true, include the inter frame space
+ *	assuming no bus idle (i.e. only the intermission). Strictly
+ *	speaking, the inter frame space is not part of the
+ *	frame. However, it is needed when calculating the delay
+ *	between the Start Of Frame of two consecutive frames.
+ * @data_len: length of the data field in bytes. Correspond to
+ *	can(fd)_frame->len. Should be zero for remote frames. No
+ *	sanitization is done on @data_len and it shall have no side
+ *	effects.
+ *
+ * Return: the numbers of bits on the wire of a CAN frame.
+ */
+#define can_frame_bits(is_fd, is_eff, bitstuffing,		\
+		       intermission, data_len)			\
+(								\
+	is_fd ? __can_fd_frame_bits(is_eff, bitstuffing,	\
+				    intermission, data_len) :	\
+		__can_cc_frame_bits(is_eff, bitstuffing,	\
+				    intermission, data_len)	\
+)
+
+/*
+ * Number of bytes in a CAN frame
+ * (rounded up, including intermission)
+ */
+#define can_frame_bytes(is_fd, is_eff, bitstuffing, data_len)	\
+	DIV_ROUND_UP(can_frame_bits(is_fd, is_eff, bitstuffing,	\
+				    true, data_len),		\
+		     BITS_PER_BYTE)
 
 /*
  * Maximum size of a Classical CAN frame
- * (rounded up and ignoring bitstuffing)
+ * (rounded up, ignoring bitstuffing but including intermission)
  */
-#define CAN_FRAME_LEN_MAX (CAN_FRAME_OVERHEAD_EFF + CAN_MAX_DLEN)
+#define CAN_FRAME_LEN_MAX can_frame_bytes(false, true, false, CAN_MAX_DLEN)
 
 /*
  * Maximum size of a CAN-FD frame
- * (rounded up and ignoring bitstuffing)
+ * (rounded up, ignoring dynamic bitstuffing but including intermission)
  */
-#define CANFD_FRAME_LEN_MAX (CANFD_FRAME_OVERHEAD_EFF + CANFD_MAX_DLEN)
+#define CANFD_FRAME_LEN_MAX can_frame_bytes(true, true, false, CANFD_MAX_DLEN)
 
 /*
  * can_cc_dlc2len(value) - convert a given data length code (dlc) of a
diff --git a/include/uapi/linux/can.h b/include/uapi/linux/can.h
index dd645ea72306..939db2388208 100644
--- a/include/uapi/linux/can.h
+++ b/include/uapi/linux/can.h
@@ -285,6 +285,5 @@ struct can_filter {
 };
 
 #define CAN_INV_FILTER 0x20000000U /* to be set in can_filter.can_id */
-#define CAN_RAW_FILTER_MAX 512 /* maximum number of can_filter set via setsockopt() */
 
 #endif /* !_UAPI_CAN_H */
diff --git a/include/uapi/linux/can/raw.h b/include/uapi/linux/can/raw.h
index ff12f525c37c..31622c9b7988 100644
--- a/include/uapi/linux/can/raw.h
+++ b/include/uapi/linux/can/raw.h
@@ -49,6 +49,8 @@
 #include <linux/can.h>
 
 #define SOL_CAN_RAW (SOL_CAN_BASE + CAN_RAW)
+#define CAN_RAW_FILTER_MAX 512 /* maximum number of can_filter set via setsockopt() */
+
 enum {
 	SCM_CAN_RAW_ERRQUEUE = 1,
 };