Merge branch 'net-xilinx-axienet-enable-adaptive-irq-coalescing-with-dim'

Sean Anderson says: ==================== net: xilinx: axienet: Enable adaptive IRQ coalescing with DIM To improve performance without sacrificing latency under low load, enable DIM. While I appreciate not having to write the library myself, I do think there are many unusual aspects to DIM, as detailed in the last patch. ==================== Link: https://patch.msgid.link/20250206201036.1516800-1-sean.anderson@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-13 18:49:22 -04:00 · 2025-02-10 18:53:43 -08:00
parent 848b09d53d e1d27d29db
commit d28e2d7f5d
3 changed files with 265 additions and 79 deletions
--- a/drivers/net/ethernet/xilinx/Kconfig
+++ b/drivers/net/ethernet/xilinx/Kconfig
@@ -28,6 +28,7 @@ config XILINX_AXI_EMAC
 	depends on HAS_IOMEM
 	depends on XILINX_DMA
 	select PHYLINK
+	select DIMLIB
 	help
 	  This driver supports the 10/100/1000 Ethernet from Xilinx for the
 	  AXI bus interface used in Xilinx Virtex FPGAs and Soc's.
--- a/drivers/net/ethernet/xilinx/xilinx_axienet.h
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet.h
@@ -9,6 +9,7 @@
 #ifndef XILINX_AXIENET_H
 #define XILINX_AXIENET_H

+#include <linux/dim.h>
 #include <linux/netdevice.h>
 #include <linux/spinlock.h>
 #include <linux/interrupt.h>
@@ -112,9 +113,6 @@
 #define XAXIDMA_DELAY_MASK		0xFF000000 /* Delay timeout counter */
 #define XAXIDMA_COALESCE_MASK		0x00FF0000 /* Coalesce counter */

-#define XAXIDMA_DELAY_SHIFT		24
-#define XAXIDMA_COALESCE_SHIFT		16
-
 #define XAXIDMA_IRQ_IOC_MASK		0x00001000 /* Completion intr */
 #define XAXIDMA_IRQ_DELAY_MASK		0x00002000 /* Delay interrupt */
 #define XAXIDMA_IRQ_ERROR_MASK		0x00004000 /* Error interrupt */
@@ -126,8 +124,7 @@
 /* Default TX/RX Threshold and delay timer values for SGDMA mode */
 #define XAXIDMA_DFT_TX_THRESHOLD	24
 #define XAXIDMA_DFT_TX_USEC		50
-#define XAXIDMA_DFT_RX_THRESHOLD	1
-#define XAXIDMA_DFT_RX_USEC		50
+#define XAXIDMA_DFT_RX_USEC		16

 #define XAXIDMA_BD_CTRL_TXSOF_MASK	0x08000000 /* First tx packet */
 #define XAXIDMA_BD_CTRL_TXEOF_MASK	0x04000000 /* Last tx packet */
@@ -487,7 +484,12 @@ struct skbuf_dma_descriptor {
 * @regs:	Base address for the axienet_local device address space
 * @dma_regs:	Base address for the axidma device address space
 * @napi_rx:	NAPI RX control structure
+ * @rx_dim:     DIM state for the receive queue
+ * @rx_dim_enabled: Whether DIM is enabled or not
+ * @rx_irqs:    Number of interrupts
+ * @rx_cr_lock: Lock protecting @rx_dma_cr, its register, and @rx_dma_started
 * @rx_dma_cr:  Nominal content of RX DMA control register
+ * @rx_dma_started: Set when RX DMA is started
 * @rx_bd_v:	Virtual address of the RX buffer descriptor ring
 * @rx_bd_p:	Physical address(start address) of the RX buffer descr. ring
 * @rx_bd_num:	Size of RX buffer descriptor ring
@@ -497,7 +499,9 @@ struct skbuf_dma_descriptor {
 * @rx_bytes:	RX byte count for statistics
 * @rx_stat_sync: Synchronization object for RX stats
 * @napi_tx:	NAPI TX control structure
+ * @tx_cr_lock: Lock protecting @tx_dma_cr, its register, and @tx_dma_started
 * @tx_dma_cr:  Nominal content of TX DMA control register
+ * @tx_dma_started: Set when TX DMA is started
 * @tx_bd_v:	Virtual address of the TX buffer descriptor ring
 * @tx_bd_p:	Physical address(start address) of the TX buffer descr. ring
 * @tx_bd_num:	Size of TX buffer descriptor ring
@@ -532,10 +536,6 @@ struct skbuf_dma_descriptor {
 *		  supported, the maximum frame size would be 9k. Else it is
 *		  1522 bytes (assuming support for basic VLAN)
 * @rxmem:	Stores rx memory size for jumbo frame handling.
- * @coalesce_count_rx:	Store the irq coalesce on RX side.
- * @coalesce_usec_rx:	IRQ coalesce delay for RX
- * @coalesce_count_tx:	Store the irq coalesce on TX side.
- * @coalesce_usec_tx:	IRQ coalesce delay for TX
 * @use_dmaengine: flag to check dmaengine framework usage.
 * @tx_chan:	TX DMA channel.
 * @rx_chan:	RX DMA channel.
@@ -569,7 +569,12 @@ struct axienet_local {
 	void __iomem *dma_regs;

 	struct napi_struct napi_rx;
+	struct dim rx_dim;
+	bool rx_dim_enabled;
+	u16 rx_irqs;
+	spinlock_t rx_cr_lock;
 	u32 rx_dma_cr;
+	bool rx_dma_started;
 	struct axidma_bd *rx_bd_v;
 	dma_addr_t rx_bd_p;
 	u32 rx_bd_num;
@@ -579,7 +584,9 @@ struct axienet_local {
 	struct u64_stats_sync rx_stat_sync;

 	struct napi_struct napi_tx;
+	spinlock_t tx_cr_lock;
 	u32 tx_dma_cr;
+	bool tx_dma_started;
 	struct axidma_bd *tx_bd_v;
 	dma_addr_t tx_bd_p;
 	u32 tx_bd_num;
@@ -610,10 +617,6 @@ struct axienet_local {
 	u32 max_frm_size;
 	u32 rxmem;

-	u32 coalesce_count_rx;
-	u32 coalesce_usec_rx;
-	u32 coalesce_count_tx;
-	u32 coalesce_usec_tx;
 	u8  use_dmaengine;
 	struct dma_chan *tx_chan;
 	struct dma_chan *rx_chan;
--- a/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
+++ b/drivers/net/ethernet/xilinx/xilinx_axienet_main.c
@@ -223,23 +223,62 @@ static void axienet_dma_bd_release(struct net_device *ndev)
 			  lp->rx_bd_p);
 }

-/**
- * axienet_usec_to_timer - Calculate IRQ delay timer value
- * @lp:		Pointer to the axienet_local structure
- * @coalesce_usec: Microseconds to convert into timer value
- */
-static u32 axienet_usec_to_timer(struct axienet_local *lp, u32 coalesce_usec)
+static u64 axienet_dma_rate(struct axienet_local *lp)
 {
-	u32 result;
-	u64 clk_rate = 125000000; /* arbitrary guess if no clock rate set */
-
 	if (lp->axi_clk)
-		clk_rate = clk_get_rate(lp->axi_clk);
+		return clk_get_rate(lp->axi_clk);
+	return 125000000; /* arbitrary guess if no clock rate set */
+}

-	/* 1 Timeout Interval = 125 * (clock period of SG clock) */
-	result = DIV64_U64_ROUND_CLOSEST((u64)coalesce_usec * clk_rate,
-					 XAXIDMA_DELAY_SCALE);
-	return min(result, FIELD_MAX(XAXIDMA_DELAY_MASK));
+/**
+ * axienet_calc_cr() - Calculate control register value
+ * @lp: Device private data
+ * @count: Number of completions before an interrupt
+ * @usec: Microseconds after the last completion before an interrupt
+ *
+ * Calculate a control register value based on the coalescing settings. The
+ * run/stop bit is not set.
+ */
+static u32 axienet_calc_cr(struct axienet_local *lp, u32 count, u32 usec)
+{
+	u32 cr;
+
+	cr = FIELD_PREP(XAXIDMA_COALESCE_MASK, count) | XAXIDMA_IRQ_IOC_MASK |
+	     XAXIDMA_IRQ_ERROR_MASK;
+	/* Only set interrupt delay timer if not generating an interrupt on
+	 * the first packet. Otherwise leave at 0 to disable delay interrupt.
+	 */
+	if (count > 1) {
+		u64 clk_rate = axienet_dma_rate(lp);
+		u32 timer;
+
+		/* 1 Timeout Interval = 125 * (clock period of SG clock) */
+		timer = DIV64_U64_ROUND_CLOSEST((u64)usec * clk_rate,
+						XAXIDMA_DELAY_SCALE);
+
+		timer = min(timer, FIELD_MAX(XAXIDMA_DELAY_MASK));
+		cr |= FIELD_PREP(XAXIDMA_DELAY_MASK, timer) |
+		      XAXIDMA_IRQ_DELAY_MASK;
+	}
+
+	return cr;
+}
+
+/**
+ * axienet_coalesce_params() - Extract coalesce parameters from the CR
+ * @lp: Device private data
+ * @cr: The control register to parse
+ * @count: Number of packets before an interrupt
+ * @usec: Idle time (in usec) before an interrupt
+ */
+static void axienet_coalesce_params(struct axienet_local *lp, u32 cr,
+				    u32 *count, u32 *usec)
+{
+	u64 clk_rate = axienet_dma_rate(lp);
+	u64 timer = FIELD_GET(XAXIDMA_DELAY_MASK, cr);
+
+	*count = FIELD_GET(XAXIDMA_COALESCE_MASK, cr);
+	*usec = DIV64_U64_ROUND_CLOSEST(timer * XAXIDMA_DELAY_SCALE, clk_rate);
 }

 /**
@@ -248,29 +287,11 @@ static u32 axienet_usec_to_timer(struct axienet_local *lp, u32 coalesce_usec)
 */
 static void axienet_dma_start(struct axienet_local *lp)
 {
-	/* Start updating the Rx channel control register */
-	lp->rx_dma_cr = (lp->coalesce_count_rx << XAXIDMA_COALESCE_SHIFT) |
-			XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_ERROR_MASK;
-	/* Only set interrupt delay timer if not generating an interrupt on
-	 * the first RX packet. Otherwise leave at 0 to disable delay interrupt.
-	 */
-	if (lp->coalesce_count_rx > 1)
-		lp->rx_dma_cr |= (axienet_usec_to_timer(lp, lp->coalesce_usec_rx)
-					<< XAXIDMA_DELAY_SHIFT) |
-				 XAXIDMA_IRQ_DELAY_MASK;
-	axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, lp->rx_dma_cr);
+	spin_lock_irq(&lp->rx_cr_lock);

-	/* Start updating the Tx channel control register */
-	lp->tx_dma_cr = (lp->coalesce_count_tx << XAXIDMA_COALESCE_SHIFT) |
-			XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_ERROR_MASK;
-	/* Only set interrupt delay timer if not generating an interrupt on
-	 * the first TX packet. Otherwise leave at 0 to disable delay interrupt.
-	 */
-	if (lp->coalesce_count_tx > 1)
-		lp->tx_dma_cr |= (axienet_usec_to_timer(lp, lp->coalesce_usec_tx)
-					<< XAXIDMA_DELAY_SHIFT) |
-				 XAXIDMA_IRQ_DELAY_MASK;
-	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, lp->tx_dma_cr);
+	/* Start updating the Rx channel control register */
+	lp->rx_dma_cr &= ~XAXIDMA_CR_RUNSTOP_MASK;
+	axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, lp->rx_dma_cr);

 	/* Populate the tail pointer and bring the Rx Axi DMA engine out of
 	 * halted state. This will make the Rx side ready for reception.
@@ -280,6 +301,14 @@ static void axienet_dma_start(struct axienet_local *lp)
 	axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, lp->rx_dma_cr);
 	axienet_dma_out_addr(lp, XAXIDMA_RX_TDESC_OFFSET, lp->rx_bd_p +
 			     (sizeof(*lp->rx_bd_v) * (lp->rx_bd_num - 1)));
+	lp->rx_dma_started = true;
+
+	spin_unlock_irq(&lp->rx_cr_lock);
+	spin_lock_irq(&lp->tx_cr_lock);
+
+	/* Start updating the Tx channel control register */
+	lp->tx_dma_cr &= ~XAXIDMA_CR_RUNSTOP_MASK;
+	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, lp->tx_dma_cr);

 	/* Write to the RS (Run-stop) bit in the Tx channel control register.
 	 * Tx channel is now ready to run. But only after we write to the
@@ -288,6 +317,9 @@ static void axienet_dma_start(struct axienet_local *lp)
 	axienet_dma_out_addr(lp, XAXIDMA_TX_CDESC_OFFSET, lp->tx_bd_p);
 	lp->tx_dma_cr |= XAXIDMA_CR_RUNSTOP_MASK;
 	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, lp->tx_dma_cr);
+	lp->tx_dma_started = true;
+
+	spin_unlock_irq(&lp->tx_cr_lock);
 }

 /**
@@ -623,14 +655,22 @@ static void axienet_dma_stop(struct axienet_local *lp)
 	int count;
 	u32 cr, sr;

-	cr = axienet_dma_in32(lp, XAXIDMA_RX_CR_OFFSET);
-	cr &= ~(XAXIDMA_CR_RUNSTOP_MASK | XAXIDMA_IRQ_ALL_MASK);
+	spin_lock_irq(&lp->rx_cr_lock);
+
+	cr = lp->rx_dma_cr & ~(XAXIDMA_CR_RUNSTOP_MASK | XAXIDMA_IRQ_ALL_MASK);
 	axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr);
+	lp->rx_dma_started = false;
+
+	spin_unlock_irq(&lp->rx_cr_lock);
 	synchronize_irq(lp->rx_irq);

-	cr = axienet_dma_in32(lp, XAXIDMA_TX_CR_OFFSET);
-	cr &= ~(XAXIDMA_CR_RUNSTOP_MASK | XAXIDMA_IRQ_ALL_MASK);
+	spin_lock_irq(&lp->tx_cr_lock);
+
+	cr = lp->tx_dma_cr & ~(XAXIDMA_CR_RUNSTOP_MASK | XAXIDMA_IRQ_ALL_MASK);
 	axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr);
+	lp->tx_dma_started = false;
+
+	spin_unlock_irq(&lp->tx_cr_lock);
 	synchronize_irq(lp->tx_irq);

 	/* Give DMAs a chance to halt gracefully */
@@ -979,7 +1019,9 @@ static int axienet_tx_poll(struct napi_struct *napi, int budget)
 		 * cause an immediate interrupt if any TX packets are
 		 * already pending.
 		 */
+		spin_lock_irq(&lp->tx_cr_lock);
 		axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, lp->tx_dma_cr);
+		spin_unlock_irq(&lp->tx_cr_lock);
 	}
 	return packets;
 }
@@ -1241,11 +1283,25 @@ static int axienet_rx_poll(struct napi_struct *napi, int budget)
 		axienet_dma_out_addr(lp, XAXIDMA_RX_TDESC_OFFSET, tail_p);

 	if (packets < budget && napi_complete_done(napi, packets)) {
+		if (READ_ONCE(lp->rx_dim_enabled)) {
+			struct dim_sample sample = {
+				.time = ktime_get(),
+				/* Safe because we are the only writer */
+				.pkt_ctr = u64_stats_read(&lp->rx_packets),
+				.byte_ctr = u64_stats_read(&lp->rx_bytes),
+				.event_ctr = READ_ONCE(lp->rx_irqs),
+			};
+
+			net_dim(&lp->rx_dim, &sample);
+		}
+
 		/* Re-enable RX completion interrupts. This should
 		 * cause an immediate interrupt if any RX packets are
 		 * already pending.
 		 */
+		spin_lock_irq(&lp->rx_cr_lock);
 		axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, lp->rx_dma_cr);
+		spin_unlock_irq(&lp->rx_cr_lock);
 	}
 	return packets;
 }
@@ -1283,11 +1339,14 @@ static irqreturn_t axienet_tx_irq(int irq, void *_ndev)
 		/* Disable further TX completion interrupts and schedule
 		 * NAPI to handle the completions.
 		 */
-		u32 cr = lp->tx_dma_cr;
-
-		cr &= ~(XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
 		if (napi_schedule_prep(&lp->napi_tx)) {
+			u32 cr;
+
+			spin_lock(&lp->tx_cr_lock);
+			cr = lp->tx_dma_cr;
+			cr &= ~(XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
 			axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr);
+			spin_unlock(&lp->tx_cr_lock);
 			__napi_schedule(&lp->napi_tx);
 		}
 	}
@@ -1328,11 +1387,16 @@ static irqreturn_t axienet_rx_irq(int irq, void *_ndev)
 		/* Disable further RX completion interrupts and schedule
 		 * NAPI receive.
 		 */
-		u32 cr = lp->rx_dma_cr;
-
-		cr &= ~(XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
+		WRITE_ONCE(lp->rx_irqs, READ_ONCE(lp->rx_irqs) + 1);
 		if (napi_schedule_prep(&lp->napi_rx)) {
+			u32 cr;
+
+			spin_lock(&lp->rx_cr_lock);
+			cr = lp->rx_dma_cr;
+			cr &= ~(XAXIDMA_IRQ_IOC_MASK | XAXIDMA_IRQ_DELAY_MASK);
 			axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr);
+			spin_unlock(&lp->rx_cr_lock);
+
 			__napi_schedule(&lp->napi_rx);
 		}
 	}
@@ -1625,6 +1689,7 @@ static int axienet_open(struct net_device *ndev)
 	if (lp->eth_irq > 0)
 		free_irq(lp->eth_irq, ndev);
 err_phy:
+	cancel_work_sync(&lp->rx_dim.work);
 	cancel_delayed_work_sync(&lp->stats_work);
 	phylink_stop(lp->phylink);
 	phylink_disconnect_phy(lp->phylink);
@@ -1654,6 +1719,7 @@ static int axienet_stop(struct net_device *ndev)
 		napi_disable(&lp->napi_rx);
 	}

+	cancel_work_sync(&lp->rx_dim.work);
 	cancel_delayed_work_sync(&lp->stats_work);

 	phylink_stop(lp->phylink);
@@ -1998,6 +2064,87 @@ axienet_ethtools_set_pauseparam(struct net_device *ndev,
 	return phylink_ethtool_set_pauseparam(lp->phylink, epauseparm);
 }

+/**
+ * axienet_update_coalesce_rx() - Set RX CR
+ * @lp: Device private data
+ * @cr: Value to write to the RX CR
+ * @mask: Bits to set from @cr
+ */
+static void axienet_update_coalesce_rx(struct axienet_local *lp, u32 cr,
+				       u32 mask)
+{
+	spin_lock_irq(&lp->rx_cr_lock);
+	lp->rx_dma_cr &= ~mask;
+	lp->rx_dma_cr |= cr;
+	/* If DMA isn't started, then the settings will be applied the next
+	 * time dma_start() is called.
+	 */
+	if (lp->rx_dma_started) {
+		u32 reg = axienet_dma_in32(lp, XAXIDMA_RX_CR_OFFSET);
+
+		/* Don't enable IRQs if they are disabled by NAPI */
+		if (reg & XAXIDMA_IRQ_ALL_MASK)
+			cr = lp->rx_dma_cr;
+		else
+			cr = lp->rx_dma_cr & ~XAXIDMA_IRQ_ALL_MASK;
+		axienet_dma_out32(lp, XAXIDMA_RX_CR_OFFSET, cr);
+	}
+	spin_unlock_irq(&lp->rx_cr_lock);
+}
+
+/**
+ * axienet_dim_coalesce_count_rx() - RX coalesce count for DIM
+ * @lp: Device private data
+ */
+static u32 axienet_dim_coalesce_count_rx(struct axienet_local *lp)
+{
+	return min(1 << (lp->rx_dim.profile_ix << 1), 255);
+}
+
+/**
+ * axienet_rx_dim_work() - Adjust RX DIM settings
+ * @work: The work struct
+ */
+static void axienet_rx_dim_work(struct work_struct *work)
+{
+	struct axienet_local *lp =
+		container_of(work, struct axienet_local, rx_dim.work);
+	u32 cr = axienet_calc_cr(lp, axienet_dim_coalesce_count_rx(lp), 0);
+	u32 mask = XAXIDMA_COALESCE_MASK | XAXIDMA_IRQ_IOC_MASK |
+		   XAXIDMA_IRQ_ERROR_MASK;
+
+	axienet_update_coalesce_rx(lp, cr, mask);
+	lp->rx_dim.state = DIM_START_MEASURE;
+}
+
+/**
+ * axienet_update_coalesce_tx() - Set TX CR
+ * @lp: Device private data
+ * @cr: Value to write to the TX CR
+ * @mask: Bits to set from @cr
+ */
+static void axienet_update_coalesce_tx(struct axienet_local *lp, u32 cr,
+				       u32 mask)
+{
+	spin_lock_irq(&lp->tx_cr_lock);
+	lp->tx_dma_cr &= ~mask;
+	lp->tx_dma_cr |= cr;
+	/* If DMA isn't started, then the settings will be applied the next
+	 * time dma_start() is called.
+	 */
+	if (lp->tx_dma_started) {
+		u32 reg = axienet_dma_in32(lp, XAXIDMA_TX_CR_OFFSET);
+
+		/* Don't enable IRQs if they are disabled by NAPI */
+		if (reg & XAXIDMA_IRQ_ALL_MASK)
+			cr = lp->tx_dma_cr;
+		else
+			cr = lp->tx_dma_cr & ~XAXIDMA_IRQ_ALL_MASK;
+		axienet_dma_out32(lp, XAXIDMA_TX_CR_OFFSET, cr);
+	}
+	spin_unlock_irq(&lp->tx_cr_lock);
+}
+
 /**
 * axienet_ethtools_get_coalesce - Get DMA interrupt coalescing count.
 * @ndev:	Pointer to net_device structure
@@ -2018,11 +2165,23 @@ axienet_ethtools_get_coalesce(struct net_device *ndev,
 			      struct netlink_ext_ack *extack)
 {
 	struct axienet_local *lp = netdev_priv(ndev);
+	u32 cr;

-	ecoalesce->rx_max_coalesced_frames = lp->coalesce_count_rx;
-	ecoalesce->rx_coalesce_usecs = lp->coalesce_usec_rx;
-	ecoalesce->tx_max_coalesced_frames = lp->coalesce_count_tx;
-	ecoalesce->tx_coalesce_usecs = lp->coalesce_usec_tx;
+	ecoalesce->use_adaptive_rx_coalesce = lp->rx_dim_enabled;
+
+	spin_lock_irq(&lp->rx_cr_lock);
+	cr = lp->rx_dma_cr;
+	spin_unlock_irq(&lp->rx_cr_lock);
+	axienet_coalesce_params(lp, cr,
+				&ecoalesce->rx_max_coalesced_frames,
+				&ecoalesce->rx_coalesce_usecs);
+
+	spin_lock_irq(&lp->tx_cr_lock);
+	cr = lp->tx_dma_cr;
+	spin_unlock_irq(&lp->tx_cr_lock);
+	axienet_coalesce_params(lp, cr,
+				&ecoalesce->tx_max_coalesced_frames,
+				&ecoalesce->tx_coalesce_usecs);
 	return 0;
 }

@@ -2046,12 +2205,9 @@ axienet_ethtools_set_coalesce(struct net_device *ndev,
 			      struct netlink_ext_ack *extack)
 {
 	struct axienet_local *lp = netdev_priv(ndev);
-
-	if (netif_running(ndev)) {
-		NL_SET_ERR_MSG(extack,
-			       "Please stop netif before applying configuration");
-		return -EBUSY;
-	}
+	bool new_dim = ecoalesce->use_adaptive_rx_coalesce;
+	bool old_dim = lp->rx_dim_enabled;
+	u32 cr, mask = ~XAXIDMA_CR_RUNSTOP_MASK;

 	if (ecoalesce->rx_max_coalesced_frames > 255 ||
 	    ecoalesce->tx_max_coalesced_frames > 255) {
@@ -2065,7 +2221,7 @@ axienet_ethtools_set_coalesce(struct net_device *ndev,
 		return -EINVAL;
 	}

-	if ((ecoalesce->rx_max_coalesced_frames > 1 &&
+	if (((ecoalesce->rx_max_coalesced_frames > 1 || new_dim) &&
 	     !ecoalesce->rx_coalesce_usecs) ||
 	    (ecoalesce->tx_max_coalesced_frames > 1 &&
 	     !ecoalesce->tx_coalesce_usecs)) {
@@ -2074,11 +2230,31 @@ axienet_ethtools_set_coalesce(struct net_device *ndev,
 		return -EINVAL;
 	}

-	lp->coalesce_count_rx = ecoalesce->rx_max_coalesced_frames;
-	lp->coalesce_usec_rx = ecoalesce->rx_coalesce_usecs;
-	lp->coalesce_count_tx = ecoalesce->tx_max_coalesced_frames;
-	lp->coalesce_usec_tx = ecoalesce->tx_coalesce_usecs;
+	if (new_dim && !old_dim) {
+		cr = axienet_calc_cr(lp, axienet_dim_coalesce_count_rx(lp),
+				     ecoalesce->rx_coalesce_usecs);
+	} else if (!new_dim) {
+		if (old_dim) {
+			WRITE_ONCE(lp->rx_dim_enabled, false);
+			napi_synchronize(&lp->napi_rx);
+			flush_work(&lp->rx_dim.work);
+		}

+		cr = axienet_calc_cr(lp, ecoalesce->rx_max_coalesced_frames,
+				     ecoalesce->rx_coalesce_usecs);
+	} else {
+		/* Dummy value for count just to calculate timer */
+		cr = axienet_calc_cr(lp, 2, ecoalesce->rx_coalesce_usecs);
+		mask = XAXIDMA_DELAY_MASK | XAXIDMA_IRQ_DELAY_MASK;
+	}
+
+	axienet_update_coalesce_rx(lp, cr, mask);
+	if (new_dim && !old_dim)
+		WRITE_ONCE(lp->rx_dim_enabled, true);
+
+	cr = axienet_calc_cr(lp, ecoalesce->tx_max_coalesced_frames,
+			     ecoalesce->tx_coalesce_usecs);
+	axienet_update_coalesce_tx(lp, cr, ~XAXIDMA_CR_RUNSTOP_MASK);
 	return 0;
 }

@@ -2316,7 +2492,8 @@ axienet_ethtool_get_rmon_stats(struct net_device *dev,

 static const struct ethtool_ops axienet_ethtool_ops = {
 	.supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES |
-				     ETHTOOL_COALESCE_USECS,
+				     ETHTOOL_COALESCE_USECS |
+				     ETHTOOL_COALESCE_USE_ADAPTIVE_RX,
 	.get_drvinfo    = axienet_ethtools_get_drvinfo,
 	.get_regs_len   = axienet_ethtools_get_regs_len,
 	.get_regs       = axienet_ethtools_get_regs,
@@ -2858,10 +3035,15 @@ static int axienet_probe(struct platform_device *pdev)
 		axienet_set_mac_address(ndev, NULL);
 	}

-	lp->coalesce_count_rx = XAXIDMA_DFT_RX_THRESHOLD;
-	lp->coalesce_count_tx = XAXIDMA_DFT_TX_THRESHOLD;
-	lp->coalesce_usec_rx = XAXIDMA_DFT_RX_USEC;
-	lp->coalesce_usec_tx = XAXIDMA_DFT_TX_USEC;
+	spin_lock_init(&lp->rx_cr_lock);
+	spin_lock_init(&lp->tx_cr_lock);
+	INIT_WORK(&lp->rx_dim.work, axienet_rx_dim_work);
+	lp->rx_dim_enabled = true;
+	lp->rx_dim.profile_ix = 1;
+	lp->rx_dma_cr = axienet_calc_cr(lp, axienet_dim_coalesce_count_rx(lp),
+					XAXIDMA_DFT_RX_USEC);
+	lp->tx_dma_cr = axienet_calc_cr(lp, XAXIDMA_DFT_TX_THRESHOLD,
+					XAXIDMA_DFT_TX_USEC);

 	ret = axienet_mdio_setup(lp);
 	if (ret)