[Cerowrt-devel] Fwd: [PATCH net-next 4/4] net: mvneta: Add TC traffic shaping offload
Dave Taht
dave.taht at gmail.com
Fri Nov 26 15:59:30 EST 2021
---------- Forwarded message ---------
From: Maxime Chevallier <maxime.chevallier at bootlin.com>
Date: Fri, Nov 26, 2021 at 12:42 PM
Subject: [PATCH net-next 4/4] net: mvneta: Add TC traffic shaping offload
To: <davem at davemloft.net>
Cc: Maxime Chevallier <maxime.chevallier at bootlin.com>,
<netdev at vger.kernel.org>, <linux-kernel at vger.kernel.org>,
<thomas.petazzoni at bootlin.com>, <gregory.clement at bootlin.com>, Andrew
Lunn <andrew at lunn.ch>, Pali Rohár <pali at kernel.org>
The mvneta controller is able to do some tocken-bucket per-queue traffic
shaping. This commit adds support for setting these using the TC mqprio
interface.
The token-bucket parameters are customisable, but the current
implementation configures them to have a 10kbps resolution for the
rate limitation, since it allows to cover the whole range of max_rate
values from 10kbps to 5Gbps with 10kbps increments.
Signed-off-by: Maxime Chevallier <maxime.chevallier at bootlin.com>
---
drivers/net/ethernet/marvell/mvneta.c | 121 +++++++++++++++++++++++++-
1 file changed, 120 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ethernet/marvell/mvneta.c
b/drivers/net/ethernet/marvell/mvneta.c
index aba452e8abfe..ca7b3c5cfe0a 100644
--- a/drivers/net/ethernet/marvell/mvneta.c
+++ b/drivers/net/ethernet/marvell/mvneta.c
@@ -248,12 +248,39 @@
#define MVNETA_TXQ_SENT_DESC_MASK 0x3fff0000
#define MVNETA_PORT_TX_RESET 0x3cf0
#define MVNETA_PORT_TX_DMA_RESET BIT(0)
+#define MVNETA_TXQ_CMD1_REG 0x3e00
+#define MVNETA_TXQ_CMD1_BW_LIM_SEL_V1 BIT(3)
+#define MVNETA_TXQ_CMD1_BW_LIM_EN BIT(0)
+#define MVNETA_REFILL_NUM_CLK_REG 0x3e08
+#define MVNETA_REFILL_MAX_NUM_CLK 0x0000ffff
#define MVNETA_TX_MTU 0x3e0c
#define MVNETA_TX_TOKEN_SIZE 0x3e14
#define MVNETA_TX_TOKEN_SIZE_MAX 0xffffffff
+#define MVNETA_TXQ_BUCKET_REFILL_REG(q) (0x3e20 + ((q) << 2))
+#define MVNETA_TXQ_BUCKET_REFILL_PERIOD_MASK 0x3ff00000
+#define MVNETA_TXQ_BUCKET_REFILL_PERIOD_SHIFT 20
+#define MVNETA_TXQ_BUCKET_REFILL_VALUE_MAX 0x0007ffff
#define MVNETA_TXQ_TOKEN_SIZE_REG(q) (0x3e40 + ((q) << 2))
#define MVNETA_TXQ_TOKEN_SIZE_MAX 0x7fffffff
+/* The values of the bucket refill base period and refill period are taken from
+ * the reference manual, and adds up to a base resolution of 10Kbps.
This allows
+ * to cover all rate-limit values from 10Kbps up to 5Gbps
+ */
+
+/* Base period for the rate limit algorithm */
+#define MVNETA_TXQ_BUCKET_REFILL_BASE_PERIOD_NS 100
+
+/* Number of Base Period to wait between each bucket refill */
+#define MVNETA_TXQ_BUCKET_REFILL_PERIOD 1000
+
+/* The base resolution for rate limiting, in bps. Any max_rate value should be
+ * a multiple of that value.
+ */
+#define MVNETA_TXQ_RATE_LIMIT_RESOLUTION (NSEC_PER_SEC / \
+
(MVNETA_TXQ_BUCKET_REFILL_BASE_PERIOD_NS * \
+ MVNETA_TXQ_BUCKET_REFILL_PERIOD))
+
#define MVNETA_LPI_CTRL_0 0x2cc0
#define MVNETA_LPI_CTRL_1 0x2cc4
#define MVNETA_LPI_REQUEST_ENABLE BIT(0)
@@ -4906,11 +4933,75 @@ static void mvneta_map_vlan_prio_to_rxq(struct
mvneta_port *pp, u8 pri, u8 rxq)
mvreg_write(pp, MVNETA_VLAN_PRIO_TO_RXQ, val);
}
+static int mvneta_enable_per_queue_rate_limit(struct mvneta_port *pp)
+{
+ unsigned long core_clk_rate;
+ u32 refill_cycles;
+ u32 val;
+
+ core_clk_rate = clk_get_rate(pp->clk);
+ if (!core_clk_rate)
+ return -EINVAL;
+
+ refill_cycles = MVNETA_TXQ_BUCKET_REFILL_BASE_PERIOD_NS /
+ (NSEC_PER_SEC / core_clk_rate);
+
+ if (refill_cycles > MVNETA_REFILL_MAX_NUM_CLK)
+ return -EINVAL;
+
+ /* Enable bw limit algorithm version 3 */
+ val = mvreg_read(pp, MVNETA_TXQ_CMD1_REG);
+ val &= ~(MVNETA_TXQ_CMD1_BW_LIM_SEL_V1 | MVNETA_TXQ_CMD1_BW_LIM_EN);
+ mvreg_write(pp, MVNETA_TXQ_CMD1_REG, val);
+
+ /* Set the base refill rate */
+ mvreg_write(pp, MVNETA_REFILL_NUM_CLK_REG, refill_cycles);
+
+ return 0;
+}
+
+static void mvneta_disable_per_queue_rate_limit(struct mvneta_port *pp)
+{
+ u32 val = mvreg_read(pp, MVNETA_TXQ_CMD1_REG);
+
+ val |= (MVNETA_TXQ_CMD1_BW_LIM_SEL_V1 | MVNETA_TXQ_CMD1_BW_LIM_EN);
+ mvreg_write(pp, MVNETA_TXQ_CMD1_REG, val);
+}
+
+static int mvneta_setup_queue_rates(struct mvneta_port *pp, int queue,
+ u64 min_rate, u64 max_rate)
+{
+ u32 refill_val;
+ u32 val = 0;
+
+ /* Convert to from Bps to bps */
+ max_rate *= 8;
+
+ if (min_rate)
+ return -EINVAL;
+
+ if (max_rate % MVNETA_TXQ_RATE_LIMIT_RESOLUTION)
+ return -EINVAL;
+
+ refill_val = max_rate / MVNETA_TXQ_RATE_LIMIT_RESOLUTION;
+
+ if (refill_val == 0 || refill_val > MVNETA_TXQ_BUCKET_REFILL_VALUE_MAX)
+ return -EINVAL;
+
+ val = refill_val;
+ val |= (MVNETA_TXQ_BUCKET_REFILL_PERIOD <<
+ MVNETA_TXQ_BUCKET_REFILL_PERIOD_SHIFT);
+
+ mvreg_write(pp, MVNETA_TXQ_BUCKET_REFILL_REG(queue), val);
+
+ return 0;
+}
+
static int mvneta_setup_mqprio(struct net_device *dev,
struct tc_mqprio_qopt_offload *mqprio)
{
struct mvneta_port *pp = netdev_priv(dev);
- int rxq, tc;
+ int rxq, txq, tc, ret;
u8 num_tc;
if (mqprio->qopt.hw != TC_MQPRIO_HW_OFFLOAD_TCS)
@@ -4924,6 +5015,7 @@ static int mvneta_setup_mqprio(struct net_device *dev,
mvneta_clear_rx_prio_map(pp);
if (!num_tc) {
+ mvneta_disable_per_queue_rate_limit(pp);
netdev_reset_tc(dev);
return 0;
}
@@ -4944,6 +5036,33 @@ static int mvneta_setup_mqprio(struct net_device *dev,
}
}
+ if (mqprio->shaper != TC_MQPRIO_SHAPER_BW_RATE) {
+ mvneta_disable_per_queue_rate_limit(pp);
+ return 0;
+ }
+
+ if (mqprio->qopt.num_tc > txq_number)
+ return -EINVAL;
+
+ ret = mvneta_enable_per_queue_rate_limit(pp);
+ if (ret)
+ return ret;
+
+ for (tc = 0; tc < mqprio->qopt.num_tc; tc++) {
+ for (txq = mqprio->qopt.offset[tc];
+ txq < mqprio->qopt.count[tc] + mqprio->qopt.offset[tc];
+ txq++) {
+ if (txq >= txq_number)
+ return -EINVAL;
+
+ ret = mvneta_setup_queue_rates(pp, txq,
+ mqprio->min_rate[tc],
+ mqprio->max_rate[tc]);
+ if (ret)
+ return ret;
+ }
+ }
+
return 0;
}
--
2.25.4
--
I tried to build a better future, a few times:
https://wayforward.archive.org/?site=https%3A%2F%2Fwww.icei.org
Dave Täht CEO, TekLibre, LLC
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