Messages in this thread Patch in this message | | | From | Oleksij Rempel <> | Subject | [PATCH net-next v4 3/9] net: add IEEE 802.1q specific helpers | Date | Mon, 8 Apr 2024 09:47:52 +0200 |
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IEEE 802.1q specification provides recommendation and examples which can be used as good default values for different drivers.
This patch implements mapping examples documented in IEEE 802.1Q-2022 in Annex I "I.3 Traffic type to traffic class mapping" and IETF DSCP naming and mapping DSCP to Traffic Type inspired by RFC8325.
This helpers will be used in followup patches for dsa/microchip DCB implementation.
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> --- changes v4: - use -EOPNOTSUPP instead of -ENOTSUP - ieee8021q_tt_to_tc() return error if requested not supported amount of queues changes v2: - properly export symbols with EXPORT_SYMBOL_GPL() - return error if NET_IEEE8021Q_HELPERS is not enabled --- include/net/dscp.h | 76 ++++++++++++++++ include/net/ieee8021q.h | 51 +++++++++++ net/Kconfig | 4 + net/core/Makefile | 1 + net/core/ieee8021q_helpers.c | 171 +++++++++++++++++++++++++++++++++++ 5 files changed, 303 insertions(+) create mode 100644 include/net/dscp.h create mode 100644 include/net/ieee8021q.h create mode 100644 net/core/ieee8021q_helpers.c
diff --git a/include/net/dscp.h b/include/net/dscp.h new file mode 100644 index 0000000000000..ba40540868c9c --- /dev/null +++ b/include/net/dscp.h @@ -0,0 +1,76 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2024 Pengutronix, Oleksij Rempel <kernel@pengutronix.de> */ + +#ifndef __DSCP_H__ +#define __DSCP_H__ + +/* + * DSCP Pools and Codepoint Space Division: + * + * The Differentiated Services (Diffserv) architecture defines a method for + * classifying and managing network traffic using the DS field in IPv4 and IPv6 + * packet headers. This field can carry one of 64 distinct DSCP (Differentiated + * Services Code Point) values, which are divided into three pools based on + * their Least Significant Bits (LSB) patterns and intended usage. Each pool has + * a specific registration procedure for assigning DSCP values: + * + * Pool 1 (Standards Action Pool): + * - Codepoint Space: xxxxx0 + * This pool includes DSCP values ending in '0' (binary), allocated via + * Standards Action. It is intended for globally recognized traffic classes, + * ensuring interoperability across the internet. This pool encompasses + * well-known DSCP values such as CS0-CS7, AFxx, EF, and VOICE-ADMIT. + * + * Pool 2 (Experimental/Local Use Pool): + * - Codepoint Space: xxxx11 + * Reserved for DSCP values ending in '11' (binary), this pool is designated + * for Experimental or Local Use. It allows for private or temporary traffic + * marking schemes not intended for standardized global use, facilitating + * testing and network-specific configurations without impacting + * interoperability. + * + * Pool 3 (Preferential Standardization Pool): + * - Codepoint Space: xxxx01 + * Initially reserved for experimental or local use, this pool now serves as + * a secondary standardization resource should Pool 1 become exhausted. DSCP + * values ending in '01' (binary) are assigned via Standards Action, with a + * focus on adopting new, standardized traffic classes as the need arises. + * + * For pool updates see: + * https://www.iana.org/assignments/dscp-registry/dscp-registry.xhtml + */ + +/* Pool 1: Standardized DSCP values as per [RFC8126] */ +#define DSCP_CS0 0 /* 000000, [RFC2474] */ +/* CS0 is some times called default (DF) */ +#define DSCP_DF 0 /* 000000, [RFC2474] */ +#define DSCP_CS1 8 /* 001000, [RFC2474] */ +#define DSCP_CS2 16 /* 010000, [RFC2474] */ +#define DSCP_CS3 24 /* 011000, [RFC2474] */ +#define DSCP_CS4 32 /* 100000, [RFC2474] */ +#define DSCP_CS5 40 /* 101000, [RFC2474] */ +#define DSCP_CS6 48 /* 110000, [RFC2474] */ +#define DSCP_CS7 56 /* 111000, [RFC2474] */ +#define DSCP_AF11 10 /* 001010, [RFC2597] */ +#define DSCP_AF12 12 /* 001100, [RFC2597] */ +#define DSCP_AF13 14 /* 001110, [RFC2597] */ +#define DSCP_AF21 18 /* 010010, [RFC2597] */ +#define DSCP_AF22 20 /* 010100, [RFC2597] */ +#define DSCP_AF23 22 /* 010110, [RFC2597] */ +#define DSCP_AF31 26 /* 011010, [RFC2597] */ +#define DSCP_AF32 28 /* 011100, [RFC2597] */ +#define DSCP_AF33 30 /* 011110, [RFC2597] */ +#define DSCP_AF41 34 /* 100010, [RFC2597] */ +#define DSCP_AF42 36 /* 100100, [RFC2597] */ +#define DSCP_AF43 38 /* 100110, [RFC2597] */ +#define DSCP_EF 46 /* 101110, [RFC3246] */ +#define DSCP_VOICE_ADMIT 44 /* 101100, [RFC5865] */ + +/* Pool 3: Standardized assignments, previously available for experimental/local + * use + */ +#define DSCP_LE 1 /* 000001, [RFC8622] */ + +#define DSCP_MAX 64 + +#endif /* __DSCP_H__ */ diff --git a/include/net/ieee8021q.h b/include/net/ieee8021q.h new file mode 100644 index 0000000000000..08fb5a617c046 --- /dev/null +++ b/include/net/ieee8021q.h @@ -0,0 +1,51 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* Copyright (c) 2024 Pengutronix, Oleksij Rempel <kernel@pengutronix.de> */ + +#ifndef _NET_IEEE8021Q_H +#define _NET_IEEE8021Q_H + +#include <linux/errno.h> + +/** + * enum ieee8021q_traffic_type - 802.1Q traffic type priority values (802.1Q-2022) + * + * @IEEE8021Q_TT_BK: Background + * @IEEE8021Q_TT_BE: Best Effort (default). According to 802.1Q-2022, BE is 0 + * but has higher priority than BK which is 1. + * @IEEE8021Q_TT_EE: Excellent Effort + * @IEEE8021Q_TT_CA: Critical Applications + * @IEEE8021Q_TT_VI: Video, < 100 ms latency and jitter + * @IEEE8021Q_TT_VO: Voice, < 10 ms latency and jitter + * @IEEE8021Q_TT_IC: Internetwork Control + * @IEEE8021Q_TT_NC: Network Control + */ +enum ieee8021q_traffic_type { + IEEE8021Q_TT_BK = 0, + IEEE8021Q_TT_BE = 1, + IEEE8021Q_TT_EE = 2, + IEEE8021Q_TT_CA = 3, + IEEE8021Q_TT_VI = 4, + IEEE8021Q_TT_VO = 5, + IEEE8021Q_TT_IC = 6, + IEEE8021Q_TT_NC = 7, +}; + +#if IS_ENABLED(CONFIG_NET_IEEE8021Q_HELPERS) + +int ietf_dscp_to_ieee8021q_tt(int dscp); +int ieee8021q_tt_to_tc(int tt, int num_queues); + +#else + +static inline int ietf_dscp_to_ieee8021q_tt(int dscp) +{ + return -EOPNOTSUPP; +} + +static inline int ieee8021q_tt_to_tc(int tt, int num_queues) +{ + return -EOPNOTSUPP; +} + +#endif +#endif /* _NET_IEEE8021Q_H */ diff --git a/net/Kconfig b/net/Kconfig index d5ab791f7afa2..b94ee06f28c18 100644 --- a/net/Kconfig +++ b/net/Kconfig @@ -452,6 +452,10 @@ config GRO_CELLS config SOCK_VALIDATE_XMIT bool +config NET_IEEE8021Q_HELPERS + bool + default n + config NET_SELFTESTS def_tristate PHYLIB depends on PHYLIB && INET diff --git a/net/core/Makefile b/net/core/Makefile index 21d6fbc7e884c..62be9aef25285 100644 --- a/net/core/Makefile +++ b/net/core/Makefile @@ -26,6 +26,7 @@ obj-$(CONFIG_NETPOLL) += netpoll.o obj-$(CONFIG_FIB_RULES) += fib_rules.o obj-$(CONFIG_TRACEPOINTS) += net-traces.o obj-$(CONFIG_NET_DROP_MONITOR) += drop_monitor.o +obj-$(CONFIG_NET_IEEE8021Q_HELPERS) += ieee8021q_helpers.o obj-$(CONFIG_NET_SELFTESTS) += selftests.o obj-$(CONFIG_NETWORK_PHY_TIMESTAMPING) += timestamping.o obj-$(CONFIG_NET_PTP_CLASSIFY) += ptp_classifier.o diff --git a/net/core/ieee8021q_helpers.c b/net/core/ieee8021q_helpers.c new file mode 100644 index 0000000000000..3564dc83d1d3d --- /dev/null +++ b/net/core/ieee8021q_helpers.c @@ -0,0 +1,171 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) 2024 Pengutronix, Oleksij Rempel <kernel@pengutronix.de> + +#include <linux/printk.h> +#include <linux/types.h> +#include <net/dscp.h> +#include <net/ieee8021q.h> + +/* Following arrays map Traffic Types (TT) to traffic classes (TC) for different + * number of queues as shown in the example provided by IEEE 802.1Q-2022 in + * Annex I "I.3 Traffic type to traffic class mapping" and Table I-1 "Traffic + * type to traffic class mapping". + */ +static const u8 ieee8021q_8queue_tt_tc_map[] = { + [IEEE8021Q_TT_BK] = 0, + [IEEE8021Q_TT_BE] = 1, + [IEEE8021Q_TT_EE] = 2, + [IEEE8021Q_TT_CA] = 3, + [IEEE8021Q_TT_VI] = 4, + [IEEE8021Q_TT_VO] = 5, + [IEEE8021Q_TT_IC] = 6, + [IEEE8021Q_TT_NC] = 7, +}; + +static const u8 ieee8021q_7queue_tt_tc_map[] = { + [IEEE8021Q_TT_BK] = 0, + [IEEE8021Q_TT_BE] = 1, + [IEEE8021Q_TT_EE] = 2, + [IEEE8021Q_TT_CA] = 3, + [IEEE8021Q_TT_VI] = 4, [IEEE8021Q_TT_VO] = 4, + [IEEE8021Q_TT_IC] = 5, + [IEEE8021Q_TT_NC] = 6, +}; + +static const u8 ieee8021q_6queue_tt_tc_map[] = { + [IEEE8021Q_TT_BK] = 0, + [IEEE8021Q_TT_BE] = 1, + [IEEE8021Q_TT_EE] = 2, [IEEE8021Q_TT_CA] = 2, + [IEEE8021Q_TT_VI] = 3, [IEEE8021Q_TT_VO] = 3, + [IEEE8021Q_TT_IC] = 4, + [IEEE8021Q_TT_NC] = 5, +}; + +static const u8 ieee8021q_5queue_tt_tc_map[] = { + [IEEE8021Q_TT_BK] = 0, [IEEE8021Q_TT_BE] = 0, + [IEEE8021Q_TT_EE] = 1, [IEEE8021Q_TT_CA] = 1, + [IEEE8021Q_TT_VI] = 2, [IEEE8021Q_TT_VO] = 2, + [IEEE8021Q_TT_IC] = 3, + [IEEE8021Q_TT_NC] = 4, +}; + +static const u8 ieee8021q_4queue_tt_tc_map[] = { + [IEEE8021Q_TT_BK] = 0, [IEEE8021Q_TT_BE] = 0, + [IEEE8021Q_TT_EE] = 1, [IEEE8021Q_TT_CA] = 1, + [IEEE8021Q_TT_VI] = 2, [IEEE8021Q_TT_VO] = 2, + [IEEE8021Q_TT_IC] = 3, [IEEE8021Q_TT_NC] = 3, +}; + +static const u8 ieee8021q_3queue_tt_tc_map[] = { + [IEEE8021Q_TT_BK] = 0, [IEEE8021Q_TT_BE] = 0, + [IEEE8021Q_TT_EE] = 0, [IEEE8021Q_TT_CA] = 0, + [IEEE8021Q_TT_VI] = 1, [IEEE8021Q_TT_VO] = 1, + [IEEE8021Q_TT_IC] = 2, [IEEE8021Q_TT_NC] = 2, +}; + +static const u8 ieee8021q_2queue_tt_tc_map[] = { + [IEEE8021Q_TT_BK] = 0, [IEEE8021Q_TT_BE] = 0, + [IEEE8021Q_TT_EE] = 0, [IEEE8021Q_TT_CA] = 0, + [IEEE8021Q_TT_VI] = 1, [IEEE8021Q_TT_VO] = 1, + [IEEE8021Q_TT_IC] = 1, [IEEE8021Q_TT_NC] = 1, +}; + +static const u8 ieee8021q_1queue_tt_tc_map[] = { + [IEEE8021Q_TT_BK] = 0, [IEEE8021Q_TT_BE] = 0, + [IEEE8021Q_TT_EE] = 0, [IEEE8021Q_TT_CA] = 0, + [IEEE8021Q_TT_VI] = 0, [IEEE8021Q_TT_VO] = 0, + [IEEE8021Q_TT_IC] = 0, [IEEE8021Q_TT_NC] = 0, +}; + +/** + * ieee8021q_tt_to_tc - Map IEEE 802.1Q Traffic Type to Traffic Class + * @tt: IEEE 802.1Q Traffic Type + * @num_queues: Number of queues + * + * This function maps an IEEE 802.1Q Traffic Type to a Traffic Class (TC) based + * on the number of queues configured on the switch. The mapping is based on the + * example provided by IEEE 802.1Q-2022 in Annex I "I.3 Traffic type to traffic + * class mapping" and Table I-1 "Traffic type to traffic class mapping". + * + * Return: Traffic Class corresponding to the given Traffic Type or -EINVAL if + * the number of queues is not supported. -EINVAL is used to differentiate from + * -EOPNOTSUPP which is used to indicate that this library function is not + * compiled in. + */ +int ieee8021q_tt_to_tc(int tt, int num_queues) +{ + switch (num_queues) { + case 8: + return ieee8021q_8queue_tt_tc_map[tt]; + case 7: + return ieee8021q_7queue_tt_tc_map[tt]; + case 6: + return ieee8021q_6queue_tt_tc_map[tt]; + case 5: + return ieee8021q_5queue_tt_tc_map[tt]; + case 4: + return ieee8021q_4queue_tt_tc_map[tt]; + case 3: + return ieee8021q_3queue_tt_tc_map[tt]; + case 2: + return ieee8021q_2queue_tt_tc_map[tt]; + case 1: + return ieee8021q_1queue_tt_tc_map[tt]; + } + + pr_err("Invalid number of queues %d\n", num_queues); + + return -EINVAL; +} +EXPORT_SYMBOL_GPL(ieee8021q_tt_to_tc); + +/** + * ietf_dscp_to_ieee8021q_tt - Map IETF DSCP to IEEE 802.1Q Traffic Type + * @dscp: IETF DSCP value + * + * This function maps an IETF DSCP value to an IEEE 802.1Q Traffic Type (TT). + * Since there is no corresponding mapping between DSCP and IEEE 802.1Q Traffic + * Type, this function is inspired by the RFC8325 documentation which describe + * the mapping between DSCP and 802.11 User Priority (UP) values. + * + * Return: IEEE 802.1Q Traffic Type corresponding to the given DSCP value + */ + +int ietf_dscp_to_ieee8021q_tt(int dscp) +{ + switch (dscp) { + case DSCP_CS0: + case DSCP_AF11: + case DSCP_AF12: + case DSCP_AF13: + return IEEE8021Q_TT_BE; + case DSCP_CS1: + return IEEE8021Q_TT_BK; + case DSCP_CS2: + case DSCP_AF21: + case DSCP_AF22: + case DSCP_AF23: + return IEEE8021Q_TT_EE; + case DSCP_CS3: + case DSCP_AF31: + case DSCP_AF32: + case DSCP_AF33: + return IEEE8021Q_TT_CA; + case DSCP_CS4: + case DSCP_AF41: + case DSCP_AF42: + case DSCP_AF43: + return IEEE8021Q_TT_VI; + case DSCP_CS5: + case DSCP_EF: + case DSCP_VOICE_ADMIT: + return IEEE8021Q_TT_VO; + case DSCP_CS6: + return IEEE8021Q_TT_IC; + case DSCP_CS7: + return IEEE8021Q_TT_NC; + } + + return (dscp >> 3) & 0x7; +} +EXPORT_SYMBOL_GPL(ietf_dscp_to_ieee8021q_tt); -- 2.39.2
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