Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | From | Oleksij Rempel <> | Subject | [PATCH net-next v1 2/2] net: dsa: microchip: add ETS Qdisc support for KSZ9477 series | Date | Mon, 6 Mar 2023 13:49:40 +0100 |
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Add ETS Qdisc support for KSZ9477 of switches. Current implementation is limited to strict priority mode.
Tested on KSZ8563R with following configuration: tc qdisc replace dev lan2 root handle 1: ets strict 4 \ priomap 3 3 2 2 1 1 0 0 ip link add link lan2 name v1 type vlan id 1 \ egress-qos-map 0:0 1:1 2:2 3:3 4:4 5:5 6:6 7:7
and patched iperf3 version: https://github.com/esnet/iperf/pull/1476 iperf3 -c 172.17.0.1 -b100M -l1472 -t100 -u -R --sock-prio 2
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> --- drivers/net/dsa/microchip/ksz_common.c | 178 +++++++++++++++++++++++++ drivers/net/dsa/microchip/ksz_common.h | 12 ++ 2 files changed, 190 insertions(+)
diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c index ae05fe0b0a81..f32ad39c1d8d 100644 --- a/drivers/net/dsa/microchip/ksz_common.c +++ b/drivers/net/dsa/microchip/ksz_common.c @@ -3172,12 +3172,190 @@ static int ksz_setup_tc_cbs(struct dsa_switch *ds, int port, MTI_SHAPING_SRP); } +static int ksz_ets_band_to_queue(struct tc_ets_qopt_offload_replace_params *p, + int band) +{ + /* Compared to queues, bands prioritize packets differently. In strict + * priority mode, the lowest priority is assigned to Queue 0 while the + * highest priority is given to Band 0. + */ + return p->bands - 1 - band; +} + +static int ksz_queue_set_strict(struct ksz_device *dev, int port, int queue) +{ + int ret; + + /* In order to ensure proper prioritization, it is necessary to set the + * rate limit for the related queue to zero. Otherwise strict priority + * mode will not work. + */ + ret = ksz_pwrite8(dev, port, KSZ9477_REG_PORT_OUT_RATE_0 + queue, + KSZ9477_OUT_RATE_NO_LIMIT); + if (ret) + return ret; + + ret = ksz_pwrite32(dev, port, REG_PORT_MTI_QUEUE_INDEX__4, queue); + if (ret) + return ret; + + return ksz_setup_tc_mode(dev, port, MTI_SCHEDULE_STRICT_PRIO, + MTI_SHAPING_OFF); +} + +static int ksz_queue_set_wrr(struct ksz_device *dev, int port, int queue, + int weight) +{ + int ret; + + /* In order to ensure proper prioritization, it is necessary to set the + * rate limit for the related queue to zero. Otherwise weighted round + * robin mode will not work. + */ + ret = ksz_pwrite8(dev, port, KSZ9477_REG_PORT_OUT_RATE_0 + queue, + KSZ9477_OUT_RATE_NO_LIMIT); + if (ret) + return ret; + + ret = ksz_pwrite32(dev, port, REG_PORT_MTI_QUEUE_INDEX__4, queue); + if (ret) + return ret; + + ret = ksz_setup_tc_mode(dev, port, MTI_SCHEDULE_WRR, + MTI_SHAPING_OFF); + if (ret) + return ret; + + return ksz_pwrite8(dev, port, KSZ9477_PORT_MTI_QUEUE_CTRL_1, weight); +} + +static int ksz_tc_ets_add(struct ksz_device *dev, int port, + struct tc_ets_qopt_offload_replace_params *p) +{ + int ret, band, tc_prio; + u32 queue_map = 0; + + /* Configure queue scheduling mode for all bands. Currently only strict + * prio mode is supported. + */ + for (band = 0; band < p->bands; band++) { + int queue = ksz_ets_band_to_queue(p, band); + + ret = ksz_queue_set_strict(dev, port, queue); + if (ret) + return ret; + } + + /* Configure the mapping between traffic classes and queues. Note: + * priomap variable support 16 traffic classes, but the chip can handle + * only 8 classes. + */ + for (tc_prio = 0; tc_prio < ARRAY_SIZE(p->priomap); tc_prio++) { + int queue; + + if (tc_prio > KSZ9477_MAX_TC_PRIO) + break; + + queue = ksz_ets_band_to_queue(p, p->priomap[tc_prio]); + queue_map |= queue << (tc_prio * KSZ9477_PORT_TC_MAP_S); + } + + return ksz_pwrite32(dev, port, KSZ9477_PORT_MRI_TC_MAP__4, queue_map); +} + +static int ksz_tc_ets_del(struct ksz_device *dev, int port) +{ + int ret, queue; + + /* To restore the default chip configuration, set all queues to use the + * WRR scheduler with a weight of 1. + */ + for (queue = 0; queue < dev->info->num_tx_queues; queue++) { + ret = ksz_queue_set_wrr(dev, port, queue, + KSZ9477_DEFAULT_WRR_WEIGHT); + if (ret) + return ret; + } + + /* Revert the queue mapping for TC-priority to its default setting on + * the chip. + */ + return ksz_pwrite32(dev, port, KSZ9477_PORT_MRI_TC_MAP__4, + KSZ9477_DEFAULT_TC_MAP); +} + +static int ksz_tc_ets_validate(struct ksz_device *dev, int port, + struct tc_ets_qopt_offload_replace_params *p) +{ + int band; + + /* Since it is not feasible to share one port among multiple qdisc, + * the user must configure all available queues appropriately. + */ + if (p->bands != dev->info->num_tx_queues) { + dev_err(dev->dev, "Not supported amount of bands. It should be %d\n", + dev->info->num_tx_queues); + return -EOPNOTSUPP; + } + + for (band = 0; band < p->bands; ++band) { + /* The KSZ switches utilize a weighted round robin configuration + * where a certain number of packets can be transmitted from a + * queue before the next queue is serviced. For more information + * on this, refer to section 5.2.8.4 of the KSZ8565R + * documentation on the Port Transmit Queue Control 1 Register. + * However, the current ETS Qdisc implementation (as of February + * 2023) assigns a weight to each queue based on the number of + * bytes or extrapolated bandwidth in percentages. Since this + * differs from the KSZ switches' method and we don't want to + * fake support by converting bytes to packets, we have decided + * to return an error instead. + */ + if (p->quanta[band]) { + dev_err(dev->dev, "Quanta/weights configuration is not supported.\n"); + return -EOPNOTSUPP; + } + } + + return 0; +} + +static int ksz_tc_setup_qdisc_ets(struct dsa_switch *ds, int port, + struct tc_ets_qopt_offload *qopt) +{ + struct ksz_device *dev = ds->priv; + int ret; + + if (qopt->parent != TC_H_ROOT) { + dev_err(dev->dev, "Parent should be \"root\"\n"); + return -EOPNOTSUPP; + } + + switch (qopt->command) { + case TC_ETS_REPLACE: + ret = ksz_tc_ets_validate(dev, port, &qopt->replace_params); + if (ret) + return ret; + + return ksz_tc_ets_add(dev, port, &qopt->replace_params); + case TC_ETS_DESTROY: + return ksz_tc_ets_del(dev, port); + case TC_ETS_STATS: + case TC_ETS_GRAFT: + return -EOPNOTSUPP; + } + + return -EOPNOTSUPP; +} + static int ksz_setup_tc(struct dsa_switch *ds, int port, enum tc_setup_type type, void *type_data) { switch (type) { case TC_SETUP_QDISC_CBS: return ksz_setup_tc_cbs(ds, port, type_data); + case TC_SETUP_QDISC_ETS: + return ksz_tc_setup_qdisc_ets(ds, port, type_data); default: return -EOPNOTSUPP; } diff --git a/drivers/net/dsa/microchip/ksz_common.h b/drivers/net/dsa/microchip/ksz_common.h index f53834bbe896..7618a4714e06 100644 --- a/drivers/net/dsa/microchip/ksz_common.h +++ b/drivers/net/dsa/microchip/ksz_common.h @@ -657,6 +657,15 @@ static inline int is_lan937x(struct ksz_device *dev) #define KSZ8_LEGAL_PACKET_SIZE 1518 #define KSZ9477_MAX_FRAME_SIZE 9000 +#define KSZ9477_REG_PORT_OUT_RATE_0 0x0420 +#define KSZ9477_OUT_RATE_NO_LIMIT 0 + +#define KSZ9477_PORT_MRI_TC_MAP__4 0x0808 +#define KSZ9477_DEFAULT_TC_MAP 0x33221100 + +#define KSZ9477_PORT_TC_MAP_S 4 +#define KSZ9477_MAX_TC_PRIO 7 + /* CBS related registers */ #define REG_PORT_MTI_QUEUE_INDEX__4 0x0900 @@ -670,6 +679,9 @@ static inline int is_lan937x(struct ksz_device *dev) #define MTI_SHAPING_SRP 1 #define MTI_SHAPING_TIME_AWARE 2 +#define KSZ9477_PORT_MTI_QUEUE_CTRL_1 0x0915 +#define KSZ9477_DEFAULT_WRR_WEIGHT 1 + #define REG_PORT_MTI_HI_WATER_MARK 0x0916 #define REG_PORT_MTI_LO_WATER_MARK 0x0918 -- 2.30.2
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