Re: [Patch net-next 2/2] net: dsa: microchip: add support for credit based shaper

From: Paolo Abeni
Date: Thu Jan 19 2023 - 04:31:44 EST

Next message: Naman Jain: "Re: [PATCH 1/2] soc: qcom: socinfo: Change socinfo variable name and scope"
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In reply to: Arun Ramadoss: "[Patch net-next 2/2] net: dsa: microchip: add support for credit based shaper"
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Hi,

On Tue, 2023-01-17 at 20:02 +0530, Arun Ramadoss wrote:
> KSZ9477, KSZ9567, KSZ9563, KSZ8563 and LAN937x supports Credit based
> shaper. To differentiate the chip supporting cbs, tc_cbs_supported
> flag is introduced in ksz_chip_data.
> And KSZ series has 16bit Credit increment registers whereas LAN937x has
> 24bit register. The value to be programmed in the credit increment is
> determined using the successive multiplication method to convert decimal
> fraction to hexadecimal fraction.
> For example: if idleslope is 10000 and sendslope is -90000, then
> bandwidth is 10000 - (-90000) = 100000.
> The 10% bandwidth of 100Mbps means 10/100 = 0.1(decimal). This value has
> to be converted to hexa.
> 1) 0.1 * 16 = 1.6 --> fraction 0.6 Carry = 1 (MSB)
> 2) 0.6 * 16 = 9.6 --> fraction 0.6 Carry = 9
> 3) 0.6 * 16 = 9.6 --> fraction 0.6 Carry = 9
> 4) 0.6 * 16 = 9.6 --> fraction 0.6 Carry = 9
> 5) 0.6 * 16 = 9.6 --> fraction 0.6 Carry = 9
> 6) 0.6 * 16 = 9.6 --> fraction 0.6 Carry = 9 (LSB)
> Now 0.1(decimal) becomes 0.199999(Hex).
> If it is LAN937x, 24 bit value will be programmed to Credit Inc
> register, 0x199999. For others 16 bit value will be prgrammed, 0x1999.
>
> Signed-off-by: Arun Ramadoss <arun.ramadoss@xxxxxxxxxxxxx>
> ---
> drivers/net/dsa/microchip/ksz9477.c | 7 ++
> drivers/net/dsa/microchip/ksz9477.h | 1 +
> drivers/net/dsa/microchip/ksz9477_reg.h | 27 +-----
> drivers/net/dsa/microchip/ksz_common.c | 105 +++++++++++++++++++++++
> drivers/net/dsa/microchip/ksz_common.h | 20 +++++
> drivers/net/dsa/microchip/lan937x.h | 1 +
> drivers/net/dsa/microchip/lan937x_main.c | 5 ++
> drivers/net/dsa/microchip/lan937x_reg.h | 3 +
> 8 files changed, 144 insertions(+), 25 deletions(-)
>
> diff --git a/drivers/net/dsa/microchip/ksz9477.c b/drivers/net/dsa/microchip/ksz9477.c
> index 5a66d0be2876..f7a6050ddb74 100644
> --- a/drivers/net/dsa/microchip/ksz9477.c
> +++ b/drivers/net/dsa/microchip/ksz9477.c
> @@ -1170,6 +1170,13 @@ u32 ksz9477_get_port_addr(int port, int offset)
> return PORT_CTRL_ADDR(port, offset);
> }
>
> +int ksz9477_tc_cbs_set_cinc(struct ksz_device *dev, int port, u32 val)
> +{
> + val = val >> 8;
> +
> + return ksz_pwrite16(dev, port, REG_PORT_MTI_CREDIT_INCREMENT, val);
> +}
> +
> int ksz9477_switch_init(struct ksz_device *dev)
> {
> u8 data8;
> diff --git a/drivers/net/dsa/microchip/ksz9477.h b/drivers/net/dsa/microchip/ksz9477.h
> index 7c5bb3032772..50d82bf0cb59 100644
> --- a/drivers/net/dsa/microchip/ksz9477.h
> +++ b/drivers/net/dsa/microchip/ksz9477.h
> @@ -51,6 +51,7 @@ int ksz9477_mdb_del(struct ksz_device *dev, int port,
> const struct switchdev_obj_port_mdb *mdb, struct dsa_db db);
> int ksz9477_change_mtu(struct ksz_device *dev, int port, int mtu);
> void ksz9477_config_cpu_port(struct dsa_switch *ds);
> +int ksz9477_tc_cbs_set_cinc(struct ksz_device *dev, int port, u32 val);
> int ksz9477_enable_stp_addr(struct ksz_device *dev);
> int ksz9477_reset_switch(struct ksz_device *dev);
> int ksz9477_dsa_init(struct ksz_device *dev);
> diff --git a/drivers/net/dsa/microchip/ksz9477_reg.h b/drivers/net/dsa/microchip/ksz9477_reg.h
> index 4f27dadb4add..1656656a0d16 100644
> --- a/drivers/net/dsa/microchip/ksz9477_reg.h
> +++ b/drivers/net/dsa/microchip/ksz9477_reg.h
> @@ -1483,33 +1483,10 @@
>
> /* 9 - Shaping */
>
> -#define REG_PORT_MTI_QUEUE_INDEX__4 0x0900
> +#define REG_PORT_MTI_QUEUE_CTRL_0__4 0x0904
>
> -#define REG_PORT_MTI_QUEUE_CTRL_0__4 0x0904
> +#define MTI_PVID_REPLACE BIT(0)
>
> -#define MTI_PVID_REPLACE BIT(0)
> -
> -#define REG_PORT_MTI_QUEUE_CTRL_0 0x0914
> -
> -#define MTI_SCHEDULE_MODE_M 0x3
> -#define MTI_SCHEDULE_MODE_S 6
> -#define MTI_SCHEDULE_STRICT_PRIO 0
> -#define MTI_SCHEDULE_WRR 2
> -#define MTI_SHAPING_M 0x3
> -#define MTI_SHAPING_S 4
> -#define MTI_SHAPING_OFF 0
> -#define MTI_SHAPING_SRP 1
> -#define MTI_SHAPING_TIME_AWARE 2
> -
> -#define REG_PORT_MTI_QUEUE_CTRL_1 0x0915
> -
> -#define MTI_TX_RATIO_M (BIT(7) - 1)
> -
> -#define REG_PORT_MTI_QUEUE_CTRL_2__2 0x0916
> -#define REG_PORT_MTI_HI_WATER_MARK 0x0916
> -#define REG_PORT_MTI_QUEUE_CTRL_3__2 0x0918
> -#define REG_PORT_MTI_LO_WATER_MARK 0x0918
> -#define REG_PORT_MTI_QUEUE_CTRL_4__2 0x091A
> #define REG_PORT_MTI_CREDIT_INCREMENT 0x091A
>
> /* A - QM */
> diff --git a/drivers/net/dsa/microchip/ksz_common.c b/drivers/net/dsa/microchip/ksz_common.c
> index fbb107754057..53f4286a2c22 100644
> --- a/drivers/net/dsa/microchip/ksz_common.c
> +++ b/drivers/net/dsa/microchip/ksz_common.c
> @@ -23,6 +23,7 @@
> #include <linux/of_net.h>
> #include <linux/micrel_phy.h>
> #include <net/dsa.h>
> +#include <net/pkt_cls.h>
> #include <net/switchdev.h>
>
> #include "ksz_common.h"
> @@ -31,6 +32,10 @@
> #include "ksz9477.h"
> #include "lan937x.h"
>
> +#define KSZ_CBS_ENABLE ((MTI_SCHEDULE_STRICT_PRIO << MTI_SCHEDULE_MODE_S) | \
> + (MTI_SHAPING_SRP << MTI_SHAPING_S))
> +#define KSZ_CBS_DISABLE ((MTI_SCHEDULE_WRR << MTI_SCHEDULE_MODE_S) |\
> + (MTI_SHAPING_OFF << MTI_SHAPING_S))
> #define MIB_COUNTER_NUM 0x20
>
> struct ksz_stats_raw {
> @@ -250,6 +255,7 @@ static const struct ksz_dev_ops ksz9477_dev_ops = {
> .change_mtu = ksz9477_change_mtu,
> .phylink_mac_link_up = ksz9477_phylink_mac_link_up,
> .config_cpu_port = ksz9477_config_cpu_port,
> + .tc_cbs_set_cinc = ksz9477_tc_cbs_set_cinc,
> .enable_stp_addr = ksz9477_enable_stp_addr,
> .reset = ksz9477_reset_switch,
> .init = ksz9477_switch_init,
> @@ -286,6 +292,7 @@ static const struct ksz_dev_ops lan937x_dev_ops = {
> .change_mtu = lan937x_change_mtu,
> .phylink_mac_link_up = ksz9477_phylink_mac_link_up,
> .config_cpu_port = lan937x_config_cpu_port,
> + .tc_cbs_set_cinc = lan937x_tc_cbs_set_cinc,
> .enable_stp_addr = ksz9477_enable_stp_addr,
> .reset = lan937x_reset_switch,
> .init = lan937x_switch_init,
> @@ -1081,6 +1088,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
> .port_cnt = 3, /* total port count */
> .port_nirqs = 3,
> .num_tx_queues = 4,
> + .tc_cbs_supported = true,
> .ops = &ksz9477_dev_ops,
> .mib_names = ksz9477_mib_names,
> .mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
> @@ -1219,6 +1227,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
> .port_cnt = 7, /* total physical port count */
> .port_nirqs = 4,
> .num_tx_queues = 4,
> + .tc_cbs_supported = true,
> .ops = &ksz9477_dev_ops,
> .phy_errata_9477 = true,
> .mib_names = ksz9477_mib_names,
> @@ -1342,6 +1351,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
> .port_cnt = 3, /* total port count */
> .port_nirqs = 3,
> .num_tx_queues = 4,
> + .tc_cbs_supported = true,
> .ops = &ksz9477_dev_ops,
> .mib_names = ksz9477_mib_names,
> .mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
> @@ -1368,6 +1378,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
> .port_cnt = 7, /* total physical port count */
> .port_nirqs = 3,
> .num_tx_queues = 4,
> + .tc_cbs_supported = true,
> .ops = &ksz9477_dev_ops,
> .phy_errata_9477 = true,
> .mib_names = ksz9477_mib_names,
> @@ -1399,6 +1410,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
> .port_cnt = 5, /* total physical port count */
> .port_nirqs = 6,
> .num_tx_queues = 8,
> + .tc_cbs_supported = true,
> .ops = &lan937x_dev_ops,
> .mib_names = ksz9477_mib_names,
> .mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
> @@ -1424,6 +1436,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
> .port_cnt = 6, /* total physical port count */
> .port_nirqs = 6,
> .num_tx_queues = 8,
> + .tc_cbs_supported = true,
> .ops = &lan937x_dev_ops,
> .mib_names = ksz9477_mib_names,
> .mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
> @@ -1449,6 +1462,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
> .port_cnt = 8, /* total physical port count */
> .port_nirqs = 6,
> .num_tx_queues = 8,
> + .tc_cbs_supported = true,
> .ops = &lan937x_dev_ops,
> .mib_names = ksz9477_mib_names,
> .mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
> @@ -1478,6 +1492,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
> .port_cnt = 5, /* total physical port count */
> .port_nirqs = 6,
> .num_tx_queues = 8,
> + .tc_cbs_supported = true,
> .ops = &lan937x_dev_ops,
> .mib_names = ksz9477_mib_names,
> .mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
> @@ -1507,6 +1522,7 @@ const struct ksz_chip_data ksz_switch_chips[] = {
> .port_cnt = 8, /* total physical port count */
> .port_nirqs = 6,
> .num_tx_queues = 8,
> + .tc_cbs_supported = true,
> .ops = &lan937x_dev_ops,
> .mib_names = ksz9477_mib_names,
> .mib_cnt = ARRAY_SIZE(ksz9477_mib_names),
> @@ -2982,6 +2998,94 @@ static int ksz_switch_detect(struct ksz_device *dev)
> return 0;
> }
>
> +/* Bandwidth is calculated by idle slope/transmission speed. Then the Bandwidth
> + * is converted to Hex-decimal using the successive multiplication method. On
> + * every step, integer part is taken and decimal part is carry forwarded.
> + */
> +static int cinc_cal(s32 idle_slope, s32 send_slope)
> +{
> + int cinc = 0;
> + u32 txrate;
> + u32 rate;
> + u8 temp;
> + u8 i;
> +
> + txrate = idle_slope - send_slope;
> +
> + rate = idle_slope;
> +
> + /* 24 bit register */
> + for (i = 0; i < 6; i++) {
> + rate = rate * 16;
> +
> + temp = rate / txrate;

idle_slope and send_slope come directly from user-space. You must
explicitly check the values are reasonable (do not lead to divide by
0).

Cheers,

Paolo

Next message: Naman Jain: "Re: [PATCH 1/2] soc: qcom: socinfo: Change socinfo variable name and scope"
Previous message: Michal Hocko: "Re: [PATCH 17/41] mm/mmap: move VMA locking before anon_vma_lock_write call"
In reply to: Arun Ramadoss: "[Patch net-next 2/2] net: dsa: microchip: add support for credit based shaper"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]