1 files changed, 146 insertions, 26 deletions

diff --git a/drivers/net/can/m_can/m_can.c b/drivers/net/can/m_can/m_can.c
index 3752520a7d4b..34073cd077e4 100644
--- a/drivers/net/can/m_can/m_can.c
+++ b/drivers/net/can/m_can/m_can.c
@@ -8,6 +8,7 @@
  * https://github.com/linux-can/can-doc/tree/master/m_can
  */
 
+#include <linux/bitfield.h>
 #include <linux/interrupt.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
@@ -148,6 +149,16 @@ enum m_can_reg {
 #define NBTP_NTSEG2_SHIFT	0
 #define NBTP_NTSEG2_MASK	(0x7f << NBTP_NTSEG2_SHIFT)
 
+/* Timestamp Counter Configuration Register (TSCC) */
+#define TSCC_TCP_MASK		GENMASK(19, 16)
+#define TSCC_TSS_MASK		GENMASK(1, 0)
+#define TSCC_TSS_DISABLE	0x0
+#define TSCC_TSS_INTERNAL	0x1
+#define TSCC_TSS_EXTERNAL	0x2
+
+/* Timestamp Counter Value Register (TSCV) */
+#define TSCV_TSC_MASK		GENMASK(15, 0)
+
 /* Error Counter Register(ECR) */
 #define ECR_RP			BIT(15)
 #define ECR_REC_SHIFT		8
@@ -302,6 +313,7 @@ enum m_can_reg {
 #define RX_BUF_ANMF		BIT(31)
 #define RX_BUF_FDF		BIT(21)
 #define RX_BUF_BRS		BIT(20)
+#define RX_BUF_RXTS_MASK	GENMASK(15, 0)
 
 /* Tx Buffer Element */
 /* T0 */
@@ -319,6 +331,7 @@ enum m_can_reg {
 /* E1 */
 #define TX_EVENT_MM_SHIFT	TX_BUF_MM_SHIFT
 #define TX_EVENT_MM_MASK	(0xff << TX_EVENT_MM_SHIFT)
+#define TX_EVENT_TXTS_MASK	GENMASK(15, 0)
 
 static inline u32 m_can_read(struct m_can_classdev *cdev, enum m_can_reg reg)
 {
@@ -413,6 +426,20 @@ static inline void m_can_disable_all_interrupts(struct m_can_classdev *cdev)
 	m_can_write(cdev, M_CAN_ILE, 0x0);
 }
 
+/* Retrieve internal timestamp counter from TSCV.TSC, and shift it to 32-bit
+ * width.
+ */
+static u32 m_can_get_timestamp(struct m_can_classdev *cdev)
+{
+	u32 tscv;
+	u32 tsc;
+
+	tscv = m_can_read(cdev, M_CAN_TSCV);
+	tsc = FIELD_GET(TSCV_TSC_MASK, tscv);
+
+	return (tsc << 16);
+}
+
 static void m_can_clean(struct net_device *net)
 {
 	struct m_can_classdev *cdev = netdev_priv(net);
@@ -425,11 +452,33 @@ static void m_can_clean(struct net_device *net)
 			putidx = ((m_can_read(cdev, M_CAN_TXFQS) &
 				   TXFQS_TFQPI_MASK) >> TXFQS_TFQPI_SHIFT);
 
-		can_free_echo_skb(cdev->net, putidx);
+		can_free_echo_skb(cdev->net, putidx, NULL);
 		cdev->tx_skb = NULL;
 	}
 }
 
+/* For peripherals, pass skb to rx-offload, which will push skb from
+ * napi. For non-peripherals, RX is done in napi already, so push
+ * directly. timestamp is used to ensure good skb ordering in
+ * rx-offload and is ignored for non-peripherals.
+*/
+static void m_can_receive_skb(struct m_can_classdev *cdev,
+			      struct sk_buff *skb,
+			      u32 timestamp)
+{
+	if (cdev->is_peripheral) {
+		struct net_device_stats *stats = &cdev->net->stats;
+		int err;
+
+		err = can_rx_offload_queue_sorted(&cdev->offload, skb,
+						  timestamp);
+		if (err)
+			stats->rx_fifo_errors++;
+	} else {
+		netif_receive_skb(skb);
+	}
+}
+
 static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
 {
 	struct net_device_stats *stats = &dev->stats;
@@ -437,6 +486,7 @@ static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
 	struct canfd_frame *cf;
 	struct sk_buff *skb;
 	u32 id, fgi, dlc;
+	u32 timestamp = 0;
 	int i;
 
 	/* calculate the fifo get index for where to read data */
@@ -485,7 +535,9 @@ static void m_can_read_fifo(struct net_device *dev, u32 rxfs)
 	stats->rx_packets++;
 	stats->rx_bytes += cf->len;
 
-	netif_receive_skb(skb);
+	timestamp = FIELD_GET(RX_BUF_RXTS_MASK, dlc);
+
+	m_can_receive_skb(cdev, skb, timestamp);
 }
 
 static int m_can_do_rx_poll(struct net_device *dev, int quota)
@@ -501,9 +553,6 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota)
 	}
 
 	while ((rxfs & RXFS_FFL_MASK) && (quota > 0)) {
-		if (rxfs & RXFS_RFL)
-			netdev_warn(dev, "Rx FIFO 0 Message Lost\n");
-
 		m_can_read_fifo(dev, rxfs);
 
 		quota--;
@@ -519,9 +568,11 @@ static int m_can_do_rx_poll(struct net_device *dev, int quota)
 
 static int m_can_handle_lost_msg(struct net_device *dev)
 {
+	struct m_can_classdev *cdev = netdev_priv(dev);
 	struct net_device_stats *stats = &dev->stats;
 	struct sk_buff *skb;
 	struct can_frame *frame;
+	u32 timestamp = 0;
 
 	netdev_err(dev, "msg lost in rxf0\n");
 
@@ -535,7 +586,10 @@ static int m_can_handle_lost_msg(struct net_device *dev)
 	frame->can_id |= CAN_ERR_CRTL;
 	frame->data[1] = CAN_ERR_CRTL_RX_OVERFLOW;
 
-	netif_receive_skb(skb);
+	if (cdev->is_peripheral)
+		timestamp = m_can_get_timestamp(cdev);
+
+	m_can_receive_skb(cdev, skb, timestamp);
 
 	return 1;
 }
@@ -547,6 +601,7 @@ static int m_can_handle_lec_err(struct net_device *dev,
 	struct net_device_stats *stats = &dev->stats;
 	struct can_frame *cf;
 	struct sk_buff *skb;
+	u32 timestamp = 0;
 
 	cdev->can.can_stats.bus_error++;
 	stats->rx_errors++;
@@ -592,7 +647,11 @@ static int m_can_handle_lec_err(struct net_device *dev,
 
 	stats->rx_packets++;
 	stats->rx_bytes += cf->len;
-	netif_receive_skb(skb);
+
+	if (cdev->is_peripheral)
+		timestamp = m_can_get_timestamp(cdev);
+
+	m_can_receive_skb(cdev, skb, timestamp);
 
 	return 1;
 }
@@ -650,6 +709,7 @@ static int m_can_handle_state_change(struct net_device *dev,
 	struct sk_buff *skb;
 	struct can_berr_counter bec;
 	unsigned int ecr;
+	u32 timestamp = 0;
 
 	switch (new_state) {
 	case CAN_STATE_ERROR_WARNING:
@@ -711,7 +771,11 @@ static int m_can_handle_state_change(struct net_device *dev,
 
 	stats->rx_packets++;
 	stats->rx_bytes += cf->len;
-	netif_receive_skb(skb);
+
+	if (cdev->is_peripheral)
+		timestamp = m_can_get_timestamp(cdev);
+
+	m_can_receive_skb(cdev, skb, timestamp);
 
 	return 1;
 }
@@ -776,6 +840,7 @@ static int m_can_handle_protocol_error(struct net_device *dev, u32 irqstatus)
 	struct m_can_classdev *cdev = netdev_priv(dev);
 	struct can_frame *cf;
 	struct sk_buff *skb;
+	u32 timestamp = 0;
 
 	/* propagate the error condition to the CAN stack */
 	skb = alloc_can_err_skb(dev, &cf);
@@ -797,7 +862,11 @@ static int m_can_handle_protocol_error(struct net_device *dev, u32 irqstatus)
 		netdev_dbg(dev, "allocation of skb failed\n");
 		return 0;
 	}
-	netif_receive_skb(skb);
+
+	if (cdev->is_peripheral)
+		timestamp = m_can_get_timestamp(cdev);
+
+	m_can_receive_skb(cdev, skb, timestamp);
 
 	return 1;
 }
@@ -876,7 +945,7 @@ static int m_can_rx_peripheral(struct net_device *dev)
 {
 	struct m_can_classdev *cdev = netdev_priv(dev);
 
-	m_can_rx_handler(dev, 1);
+	m_can_rx_handler(dev, M_CAN_NAPI_WEIGHT);
 
 	m_can_enable_all_interrupts(cdev);
 
@@ -898,6 +967,29 @@ static int m_can_poll(struct napi_struct *napi, int quota)
 	return work_done;
 }
 
+/* Echo tx skb and update net stats. Peripherals use rx-offload for
+ * echo. timestamp is used for peripherals to ensure correct ordering
+ * by rx-offload, and is ignored for non-peripherals.
+*/
+static void m_can_tx_update_stats(struct m_can_classdev *cdev,
+				  unsigned int msg_mark,
+				  u32 timestamp)
+{
+	struct net_device *dev = cdev->net;
+	struct net_device_stats *stats = &dev->stats;
+
+	if (cdev->is_peripheral)
+		stats->tx_bytes +=
+			can_rx_offload_get_echo_skb(&cdev->offload,
+						    msg_mark,
+						    timestamp,
+						    NULL);
+	else
+		stats->tx_bytes += can_get_echo_skb(dev, msg_mark, NULL);
+
+	stats->tx_packets++;
+}
+
 static void m_can_echo_tx_event(struct net_device *dev)
 {
 	u32 txe_count = 0;
@@ -907,7 +999,6 @@ static void m_can_echo_tx_event(struct net_device *dev)
 	unsigned int msg_mark;
 
 	struct m_can_classdev *cdev = netdev_priv(dev);
-	struct net_device_stats *stats = &dev->stats;
 
 	/* read tx event fifo status */
 	m_can_txefs = m_can_read(cdev, M_CAN_TXEFS);
@@ -917,21 +1008,23 @@ static void m_can_echo_tx_event(struct net_device *dev)
 
 	/* Get and process all sent elements */
 	for (i = 0; i < txe_count; i++) {
+		u32 txe, timestamp = 0;
+
 		/* retrieve get index */
 		fgi = (m_can_read(cdev, M_CAN_TXEFS) & TXEFS_EFGI_MASK) >>
 			TXEFS_EFGI_SHIFT;
 
-		/* get message marker */
-		msg_mark = (m_can_txe_fifo_read(cdev, fgi, 4) &
-			    TX_EVENT_MM_MASK) >> TX_EVENT_MM_SHIFT;
+		/* get message marker, timestamp */
+		txe = m_can_txe_fifo_read(cdev, fgi, 4);
+		msg_mark = (txe & TX_EVENT_MM_MASK) >> TX_EVENT_MM_SHIFT;
+		timestamp = FIELD_GET(TX_EVENT_TXTS_MASK, txe);
 
 		/* ack txe element */
 		m_can_write(cdev, M_CAN_TXEFA, (TXEFA_EFAI_MASK &
 						(fgi << TXEFA_EFAI_SHIFT)));
 
 		/* update stats */
-		stats->tx_bytes += can_get_echo_skb(dev, msg_mark, NULL);
-		stats->tx_packets++;
+		m_can_tx_update_stats(cdev, msg_mark, timestamp);
 	}
 }
 
@@ -939,7 +1032,6 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 {
 	struct net_device *dev = (struct net_device *)dev_id;
 	struct m_can_classdev *cdev = netdev_priv(dev);
-	struct net_device_stats *stats = &dev->stats;
 	u32 ir;
 
 	if (pm_runtime_suspended(cdev->dev))
@@ -972,8 +1064,12 @@ static irqreturn_t m_can_isr(int irq, void *dev_id)
 	if (cdev->version == 30) {
 		if (ir & IR_TC) {
 			/* Transmission Complete Interrupt*/
-			stats->tx_bytes += can_get_echo_skb(dev, 0, NULL);
-			stats->tx_packets++;
+			u32 timestamp = 0;
+
+			if (cdev->is_peripheral)
+				timestamp = m_can_get_timestamp(cdev);
+			m_can_tx_update_stats(cdev, 0, timestamp);
+
 			can_led_event(dev, CAN_LED_EVENT_TX);
 			netif_wake_queue(dev);
 		}
@@ -1111,6 +1207,7 @@ static int m_can_set_bittiming(struct net_device *dev)
  *		- >= v3.1.x: TX FIFO is used
  * - configure mode
  * - setup bittiming
+ * - configure timestamp generation
  */
 static void m_can_chip_config(struct net_device *dev)
 {
@@ -1222,6 +1319,10 @@ static void m_can_chip_config(struct net_device *dev)
 	/* set bittiming params */
 	m_can_set_bittiming(dev);
 
+	/* enable internal timestamp generation, with a prescalar of 16. The
+	 * prescalar is applied to the nominal bit timing */
+	m_can_write(cdev, M_CAN_TSCC, FIELD_PREP(TSCC_TCP_MASK, 0xf));
+
 	m_can_config_endisable(cdev, false);
 
 	if (cdev->ops->init)
@@ -1429,6 +1530,9 @@ static int m_can_close(struct net_device *dev)
 		cdev->tx_wq = NULL;
 	}
 
+	if (cdev->is_peripheral)
+		can_rx_offload_disable(&cdev->offload);
+
 	close_candev(dev);
 	can_led_event(dev, CAN_LED_EVENT_STOP);
 
@@ -1627,6 +1731,9 @@ static int m_can_open(struct net_device *dev)
 		goto exit_disable_clks;
 	}
 
+	if (cdev->is_peripheral)
+		can_rx_offload_enable(&cdev->offload);
+
 	/* register interrupt handler */
 	if (cdev->is_peripheral) {
 		cdev->tx_skb = NULL;
@@ -1668,6 +1775,8 @@ exit_irq_fail:
 	if (cdev->is_peripheral)
 		destroy_workqueue(cdev->tx_wq);
 out_wq_fail:
+	if (cdev->is_peripheral)
+		can_rx_offload_disable(&cdev->offload);
 	close_candev(dev);
 exit_disable_clks:
 	m_can_clk_stop(cdev);
@@ -1790,11 +1899,6 @@ struct m_can_classdev *m_can_class_allocate_dev(struct device *dev,
 	}
 
 	class_dev = netdev_priv(net_dev);
-	if (!class_dev) {
-		dev_err(dev, "Failed to init netdev cdevate");
-		goto out;
-	}
-
 	class_dev->net = net_dev;
 	class_dev->dev = dev;
 	SET_NETDEV_DEV(net_dev, dev);
@@ -1821,15 +1925,22 @@ int m_can_class_register(struct m_can_classdev *cdev)
 			return ret;
 	}
 
+	if (cdev->is_peripheral) {
+		ret = can_rx_offload_add_manual(cdev->net, &cdev->offload,
+						M_CAN_NAPI_WEIGHT);
+		if (ret)
+			goto clk_disable;
+	}
+
 	ret = m_can_dev_setup(cdev);
 	if (ret)
-		goto clk_disable;
+		goto rx_offload_del;
 
 	ret = register_m_can_dev(cdev->net);
 	if (ret) {
 		dev_err(cdev->dev, "registering %s failed (err=%d)\n",
 			cdev->net->name, ret);
-		goto clk_disable;
+		goto rx_offload_del;
 	}
 
 	devm_can_led_init(cdev->net);
@@ -1842,6 +1953,13 @@ int m_can_class_register(struct m_can_classdev *cdev)
 	/* Probe finished
 	 * Stop clocks. They will be reactivated once the M_CAN device is opened
 	 */
+	m_can_clk_stop(cdev);
+
+	return 0;
+
+rx_offload_del:
+	if (cdev->is_peripheral)
+		can_rx_offload_del(&cdev->offload);
 clk_disable:
 	m_can_clk_stop(cdev);
 
@@ -1851,6 +1969,8 @@ EXPORT_SYMBOL_GPL(m_can_class_register);
 
 void m_can_class_unregister(struct m_can_classdev *cdev)
 {
+	if (cdev->is_peripheral)
+		can_rx_offload_del(&cdev->offload);
 	unregister_candev(cdev->net);
 }
 EXPORT_SYMBOL_GPL(m_can_class_unregister);