Merge branch '1GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/next-

queue

Tony Nguyen says:

====================
1GbE Intel Wired LAN Driver Updates 2021-08-27

ravindhan Gunasekaran says:

This adds support for Credit-based shaper qdisc offload from
Traffic Control system. It enables traffic prioritization and
bandwidth reservation via the Credit-Based Shaper which is
implemented in hardware by i225 controller.

Patch 1/3 adds a default cycle-time for TSN mode to be configured.

Patch 2/3 helps to separate TSN mode programming on the fly and
during reset sequence. It also simplifies handling features flags
for various TSN modes supported by i225 in the driver.

Patch 3/3 adds support for IEEE802.1Qav(CBS) standard
implemented in i225 HW. Two sets of CBS HW shapers are present
in i225 and driver enables them in the two high priority queues.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

6 files changed, 258 insertions, 49 deletions

diff --git a/drivers/net/ethernet/intel/igc/igc.h b/drivers/net/ethernet/intel/igc/igc.h
index 2d17a6da63cf..3e386c38d016 100644
--- a/drivers/net/ethernet/intel/igc/igc.h
+++ b/drivers/net/ethernet/intel/igc/igc.h
@@ -98,6 +98,13 @@ struct igc_ring {
 	u32 start_time;
 	u32 end_time;
 
+	/* CBS parameters */
+	bool cbs_enable;                /* indicates if CBS is enabled */
+	s32 idleslope;                  /* idleSlope in kbps */
+	s32 sendslope;                  /* sendSlope in kbps */
+	s32 hicredit;                   /* hiCredit in bytes */
+	s32 locredit;                   /* loCredit in bytes */
+
 	/* everything past this point are written often */
 	u16 next_to_clean;
 	u16 next_to_use;
@@ -290,6 +297,10 @@ extern char igc_driver_name[];
 #define IGC_FLAG_VLAN_PROMISC		BIT(15)
 #define IGC_FLAG_RX_LEGACY		BIT(16)
 #define IGC_FLAG_TSN_QBV_ENABLED	BIT(17)
+#define IGC_FLAG_TSN_QAV_ENABLED	BIT(18)
+
+#define IGC_FLAG_TSN_ANY_ENABLED \
+	(IGC_FLAG_TSN_QBV_ENABLED | IGC_FLAG_TSN_QAV_ENABLED)
 
 #define IGC_FLAG_RSS_FIELD_IPV4_UDP	BIT(6)
 #define IGC_FLAG_RSS_FIELD_IPV6_UDP	BIT(7)
diff --git a/drivers/net/ethernet/intel/igc/igc_defines.h b/drivers/net/ethernet/intel/igc/igc_defines.h
index c40563350a5e..a4bbee748798 100644
--- a/drivers/net/ethernet/intel/igc/igc_defines.h
+++ b/drivers/net/ethernet/intel/igc/igc_defines.h
@@ -518,6 +518,14 @@
 #define IGC_TXQCTL_QUEUE_MODE_LAUNCHT	0x00000001
 #define IGC_TXQCTL_STRICT_CYCLE		0x00000002
 #define IGC_TXQCTL_STRICT_END		0x00000004
+#define IGC_TXQCTL_QAV_SEL_MASK		0x000000C0
+#define IGC_TXQCTL_QAV_SEL_CBS0		0x00000080
+#define IGC_TXQCTL_QAV_SEL_CBS1		0x000000C0
+
+#define IGC_TQAVCC_IDLESLOPE_MASK	0xFFFF
+#define IGC_TQAVCC_KEEP_CREDITS		BIT(30)
+
+#define IGC_MAX_SR_QUEUES		2
 
 /* Receive Checksum Control */
 #define IGC_RXCSUM_CRCOFL	0x00000800   /* CRC32 offload enable */
diff --git a/drivers/net/ethernet/intel/igc/igc_main.c b/drivers/net/ethernet/intel/igc/igc_main.c
index c6c075a637ea..b877efae61df 100644
--- a/drivers/net/ethernet/intel/igc/igc_main.c
+++ b/drivers/net/ethernet/intel/igc/igc_main.c
@@ -120,7 +120,7 @@ void igc_reset(struct igc_adapter *adapter)
 	igc_ptp_reset(adapter);
 
 	/* Re-enable TSN offloading, where applicable. */
-	igc_tsn_offload_apply(adapter);
+	igc_tsn_reset(adapter);
 
 	igc_get_phy_info(hw);
 }
@@ -5749,7 +5749,6 @@ static int igc_save_launchtime_params(struct igc_adapter *adapter, int queue,
 				      bool enable)
 {
 	struct igc_ring *ring;
-	int i;
 
 	if (queue < 0 || queue >= adapter->num_tx_queues)
 		return -EINVAL;
@@ -5757,17 +5756,6 @@ static int igc_save_launchtime_params(struct igc_adapter *adapter, int queue,
 	ring = adapter->tx_ring[queue];
 	ring->launchtime_enable = enable;
 
-	if (adapter->base_time)
-		return 0;
-
-	adapter->cycle_time = NSEC_PER_SEC;
-
-	for (i = 0; i < adapter->num_tx_queues; i++) {
-		ring = adapter->tx_ring[i];
-		ring->start_time = 0;
-		ring->end_time = NSEC_PER_SEC;
-	}
-
 	return 0;
 }
 
@@ -5840,16 +5828,31 @@ static int igc_tsn_enable_launchtime(struct igc_adapter *adapter,
 	return igc_tsn_offload_apply(adapter);
 }
 
+static int igc_tsn_clear_schedule(struct igc_adapter *adapter)
+{
+	int i;
+
+	adapter->base_time = 0;
+	adapter->cycle_time = NSEC_PER_SEC;
+
+	for (i = 0; i < adapter->num_tx_queues; i++) {
+		struct igc_ring *ring = adapter->tx_ring[i];
+
+		ring->start_time = 0;
+		ring->end_time = NSEC_PER_SEC;
+	}
+
+	return 0;
+}
+
 static int igc_save_qbv_schedule(struct igc_adapter *adapter,
 				 struct tc_taprio_qopt_offload *qopt)
 {
 	u32 start_time = 0, end_time = 0;
 	size_t n;
 
-	if (!qopt->enable) {
-		adapter->base_time = 0;
-		return 0;
-	}
+	if (!qopt->enable)
+		return igc_tsn_clear_schedule(adapter);
 
 	if (adapter->base_time)
 		return -EALREADY;
@@ -5901,6 +5904,74 @@ static int igc_tsn_enable_qbv_scheduling(struct igc_adapter *adapter,
 	return igc_tsn_offload_apply(adapter);
 }
 
+static int igc_save_cbs_params(struct igc_adapter *adapter, int queue,
+			       bool enable, int idleslope, int sendslope,
+			       int hicredit, int locredit)
+{
+	bool cbs_status[IGC_MAX_SR_QUEUES] = { false };
+	struct net_device *netdev = adapter->netdev;
+	struct igc_ring *ring;
+	int i;
+
+	/* i225 has two sets of credit-based shaper logic.
+	 * Supporting it only on the top two priority queues
+	 */
+	if (queue < 0 || queue > 1)
+		return -EINVAL;
+
+	ring = adapter->tx_ring[queue];
+
+	for (i = 0; i < IGC_MAX_SR_QUEUES; i++)
+		if (adapter->tx_ring[i])
+			cbs_status[i] = adapter->tx_ring[i]->cbs_enable;
+
+	/* CBS should be enabled on the highest priority queue first in order
+	 * for the CBS algorithm to operate as intended.
+	 */
+	if (enable) {
+		if (queue == 1 && !cbs_status[0]) {
+			netdev_err(netdev,
+				   "Enabling CBS on queue1 before queue0\n");
+			return -EINVAL;
+		}
+	} else {
+		if (queue == 0 && cbs_status[1]) {
+			netdev_err(netdev,
+				   "Disabling CBS on queue0 before queue1\n");
+			return -EINVAL;
+		}
+	}
+
+	ring->cbs_enable = enable;
+	ring->idleslope = idleslope;
+	ring->sendslope = sendslope;
+	ring->hicredit = hicredit;
+	ring->locredit = locredit;
+
+	return 0;
+}
+
+static int igc_tsn_enable_cbs(struct igc_adapter *adapter,
+			      struct tc_cbs_qopt_offload *qopt)
+{
+	struct igc_hw *hw = &adapter->hw;
+	int err;
+
+	if (hw->mac.type != igc_i225)
+		return -EOPNOTSUPP;
+
+	if (qopt->queue < 0 || qopt->queue > 1)
+		return -EINVAL;
+
+	err = igc_save_cbs_params(adapter, qopt->queue, qopt->enable,
+				  qopt->idleslope, qopt->sendslope,
+				  qopt->hicredit, qopt->locredit);
+	if (err)
+		return err;
+
+	return igc_tsn_offload_apply(adapter);
+}
+
 static int igc_setup_tc(struct net_device *dev, enum tc_setup_type type,
 			void *type_data)
 {
@@ -5913,6 +5984,9 @@ static int igc_setup_tc(struct net_device *dev, enum tc_setup_type type,
 	case TC_SETUP_QDISC_ETF:
 		return igc_tsn_enable_launchtime(adapter, type_data);
 
+	case TC_SETUP_QDISC_CBS:
+		return igc_tsn_enable_cbs(adapter, type_data);
+
 	default:
 		return -EOPNOTSUPP;
 	}
@@ -6339,6 +6413,8 @@ static int igc_probe(struct pci_dev *pdev,
 
 	igc_ptp_init(adapter);
 
+	igc_tsn_clear_schedule(adapter);
+
 	/* reset the hardware with the new settings */
 	igc_reset(adapter);
 
diff --git a/drivers/net/ethernet/intel/igc/igc_regs.h b/drivers/net/ethernet/intel/igc/igc_regs.h
index dbba2eb2a247..e197a33d93a0 100644
--- a/drivers/net/ethernet/intel/igc/igc_regs.h
+++ b/drivers/net/ethernet/intel/igc/igc_regs.h
@@ -236,6 +236,9 @@
 #define IGC_ENDQT(_n)		(0x3334 + 0x4 * (_n))
 #define IGC_DTXMXPKTSZ		0x355C
 
+#define IGC_TQAVCC(_n)		(0x3004 + ((_n) * 0x40))
+#define IGC_TQAVHC(_n)		(0x300C + ((_n) * 0x40))
+
 /* System Time Registers */
 #define IGC_SYSTIML	0x0B600  /* System time register Low - RO */
 #define IGC_SYSTIMH	0x0B604  /* System time register High - RO */
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.c b/drivers/net/ethernet/intel/igc/igc_tsn.c
index 4dbbb8a32ce9..0fce22de2ab8 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.c
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.c
@@ -18,8 +18,38 @@ static bool is_any_launchtime(struct igc_adapter *adapter)
 	return false;
 }
 
+static bool is_cbs_enabled(struct igc_adapter *adapter)
+{
+	int i;
+
+	for (i = 0; i < adapter->num_tx_queues; i++) {
+		struct igc_ring *ring = adapter->tx_ring[i];
+
+		if (ring->cbs_enable)
+			return true;
+	}
+
+	return false;
+}
+
+static unsigned int igc_tsn_new_flags(struct igc_adapter *adapter)
+{
+	unsigned int new_flags = adapter->flags & ~IGC_FLAG_TSN_ANY_ENABLED;
+
+	if (adapter->base_time)
+		new_flags |= IGC_FLAG_TSN_QBV_ENABLED;
+
+	if (is_any_launchtime(adapter))
+		new_flags |= IGC_FLAG_TSN_QBV_ENABLED;
+
+	if (is_cbs_enabled(adapter))
+		new_flags |= IGC_FLAG_TSN_QAV_ENABLED;
+
+	return new_flags;
+}
+
 /* Returns the TSN specific registers to their default values after
- * TSN offloading is disabled.
+ * the adapter is reset.
  */
 static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 {
@@ -27,11 +57,6 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 	u32 tqavctrl;
 	int i;
 
-	if (!(adapter->flags & IGC_FLAG_TSN_QBV_ENABLED))
-		return 0;
-
-	adapter->cycle_time = 0;
-
 	wr32(IGC_TXPBS, I225_TXPBSIZE_DEFAULT);
 	wr32(IGC_DTXMXPKTSZ, IGC_DTXMXPKTSZ_DEFAULT);
 
@@ -41,12 +66,6 @@ static int igc_tsn_disable_offload(struct igc_adapter *adapter)
 	wr32(IGC_TQAVCTRL, tqavctrl);
 
 	for (i = 0; i < adapter->num_tx_queues; i++) {
-		struct igc_ring *ring = adapter->tx_ring[i];
-
-		ring->start_time = 0;
-		ring->end_time = 0;
-		ring->launchtime_enable = false;
-
 		wr32(IGC_TXQCTL(i), 0);
 		wr32(IGC_STQT(i), 0);
 		wr32(IGC_ENDQT(i), NSEC_PER_SEC);
@@ -68,9 +87,6 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 	ktime_t base_time, systim;
 	int i;
 
-	if (adapter->flags & IGC_FLAG_TSN_QBV_ENABLED)
-		return 0;
-
 	cycle = adapter->cycle_time;
 	base_time = adapter->base_time;
 
@@ -88,6 +104,8 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 	for (i = 0; i < adapter->num_tx_queues; i++) {
 		struct igc_ring *ring = adapter->tx_ring[i];
 		u32 txqctl = 0;
+		u16 cbs_value;
+		u32 tqavcc;
 
 		wr32(IGC_STQT(i), ring->start_time);
 		wr32(IGC_ENDQT(i), ring->end_time);
@@ -105,6 +123,90 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 		if (ring->launchtime_enable)
 			txqctl |= IGC_TXQCTL_QUEUE_MODE_LAUNCHT;
 
+		/* Skip configuring CBS for Q2 and Q3 */
+		if (i > 1)
+			goto skip_cbs;
+
+		if (ring->cbs_enable) {
+			if (i == 0)
+				txqctl |= IGC_TXQCTL_QAV_SEL_CBS0;
+			else
+				txqctl |= IGC_TXQCTL_QAV_SEL_CBS1;
+
+			/* According to i225 datasheet section 7.5.2.7, we
+			 * should set the 'idleSlope' field from TQAVCC
+			 * register following the equation:
+			 *
+			 * value = link-speed   0x7736 * BW * 0.2
+			 *         ---------- *  -----------------         (E1)
+			 *          100Mbps            2.5
+			 *
+			 * Note that 'link-speed' is in Mbps.
+			 *
+			 * 'BW' is the percentage bandwidth out of full
+			 * link speed which can be found with the
+			 * following equation. Note that idleSlope here
+			 * is the parameter from this function
+			 * which is in kbps.
+			 *
+			 *     BW =     idleSlope
+			 *          -----------------                      (E2)
+			 *          link-speed * 1000
+			 *
+			 * That said, we can come up with a generic
+			 * equation to calculate the value we should set
+			 * it TQAVCC register by replacing 'BW' in E1 by E2.
+			 * The resulting equation is:
+			 *
+			 * value = link-speed * 0x7736 * idleSlope * 0.2
+			 *         -------------------------------------   (E3)
+			 *             100 * 2.5 * link-speed * 1000
+			 *
+			 * 'link-speed' is present in both sides of the
+			 * fraction so it is canceled out. The final
+			 * equation is the following:
+			 *
+			 *     value = idleSlope * 61036
+			 *             -----------------                   (E4)
+			 *                  2500000
+			 *
+			 * NOTE: For i225, given the above, we can see
+			 *       that idleslope is represented in
+			 *       40.959433 kbps units by the value at
+			 *       the TQAVCC register (2.5Gbps / 61036),
+			 *       which reduces the granularity for
+			 *       idleslope increments.
+			 *
+			 * In i225 controller, the sendSlope and loCredit
+			 * parameters from CBS are not configurable
+			 * by software so we don't do any
+			 * 'controller configuration' in respect to
+			 * these parameters.
+			 */
+			cbs_value = DIV_ROUND_UP_ULL(ring->idleslope
+						     * 61036ULL, 2500000);
+
+			tqavcc = rd32(IGC_TQAVCC(i));
+			tqavcc &= ~IGC_TQAVCC_IDLESLOPE_MASK;
+			tqavcc |= cbs_value | IGC_TQAVCC_KEEP_CREDITS;
+			wr32(IGC_TQAVCC(i), tqavcc);
+
+			wr32(IGC_TQAVHC(i),
+			     0x80000000 + ring->hicredit * 0x7735);
+		} else {
+			/* Disable any CBS for the queue */
+			txqctl &= ~(IGC_TXQCTL_QAV_SEL_MASK);
+
+			/* Set idleSlope to zero. */
+			tqavcc = rd32(IGC_TQAVCC(i));
+			tqavcc &= ~(IGC_TQAVCC_IDLESLOPE_MASK |
+				    IGC_TQAVCC_KEEP_CREDITS);
+			wr32(IGC_TQAVCC(i), tqavcc);
+
+			/* Set hiCredit to zero. */
+			wr32(IGC_TQAVHC(i), 0);
+		}
+skip_cbs:
 		wr32(IGC_TXQCTL(i), txqctl);
 	}
 
@@ -125,33 +227,41 @@ static int igc_tsn_enable_offload(struct igc_adapter *adapter)
 	wr32(IGC_BASET_H, baset_h);
 	wr32(IGC_BASET_L, baset_l);
 
-	adapter->flags |= IGC_FLAG_TSN_QBV_ENABLED;
-
 	return 0;
 }
 
-int igc_tsn_offload_apply(struct igc_adapter *adapter)
+int igc_tsn_reset(struct igc_adapter *adapter)
 {
-	bool is_any_enabled = adapter->base_time || is_any_launchtime(adapter);
+	unsigned int new_flags;
+	int err = 0;
 
-	if (!(adapter->flags & IGC_FLAG_TSN_QBV_ENABLED) && !is_any_enabled)
-		return 0;
+	new_flags = igc_tsn_new_flags(adapter);
 
-	if (!is_any_enabled) {
-		int err = igc_tsn_disable_offload(adapter);
+	if (!(new_flags & IGC_FLAG_TSN_ANY_ENABLED))
+		return igc_tsn_disable_offload(adapter);
 
-		if (err < 0)
-			return err;
+	err = igc_tsn_enable_offload(adapter);
+	if (err < 0)
+		return err;
 
-		/* The BASET registers aren't cleared when writing
-		 * into them, force a reset if the interface is
-		 * running.
-		 */
-		if (netif_running(adapter->netdev))
-			schedule_work(&adapter->reset_task);
+	adapter->flags = new_flags;
 
+	return err;
+}
+
+int igc_tsn_offload_apply(struct igc_adapter *adapter)
+{
+	int err;
+
+	if (netif_running(adapter->netdev)) {
+		schedule_work(&adapter->reset_task);
 		return 0;
 	}
 
-	return igc_tsn_enable_offload(adapter);
+	err = igc_tsn_enable_offload(adapter);
+	if (err < 0)
+		return err;
+
+	adapter->flags = igc_tsn_new_flags(adapter);
+	return 0;
 }
diff --git a/drivers/net/ethernet/intel/igc/igc_tsn.h b/drivers/net/ethernet/intel/igc/igc_tsn.h
index f76bc86ddccd..1512307f5a52 100644
--- a/drivers/net/ethernet/intel/igc/igc_tsn.h
+++ b/drivers/net/ethernet/intel/igc/igc_tsn.h
@@ -5,5 +5,6 @@
 #define _IGC_TSN_H_
 
 int igc_tsn_offload_apply(struct igc_adapter *adapter);
+int igc_tsn_reset(struct igc_adapter *adapter);
 
 #endif /* _IGC_BASE_H */