From e0ea34158ee8c4f7536cd781010339ff28c0d24c Mon Sep 17 00:00:00 2001
From: David Arinzon <darinzon@amazon.com>
Date: Tue, 17 Jun 2025 14:05:37 +0300
Subject: [PATCH 1/9] net: ena: Add PHC support in the ENA driver

The ENA driver will be extended to support the new PHC feature using
ptp_clock interface [1]. this will provide timestamp reference for user
space to allow measuring time offset between the PHC and the system
clock in order to achieve nanosecond accuracy.

[1] - https://www.kernel.org/doc/html/latest/driver-api/ptp.html

Signed-off-by: Amit Bernstein <amitbern@amazon.com>
Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://patch.msgid.link/20250617110545.5659-2-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 .../device_drivers/ethernet/amazon/ena.rst    |   1 +
 drivers/net/ethernet/amazon/Kconfig           |   1 +
 drivers/net/ethernet/amazon/ena/Makefile      |   2 +-
 .../net/ethernet/amazon/ena/ena_admin_defs.h  |  74 ++++-
 drivers/net/ethernet/amazon/ena/ena_com.c     | 267 ++++++++++++++++++
 drivers/net/ethernet/amazon/ena/ena_com.h     |  84 ++++++
 drivers/net/ethernet/amazon/ena/ena_ethtool.c |  16 +-
 drivers/net/ethernet/amazon/ena/ena_netdev.c  |  24 +-
 drivers/net/ethernet/amazon/ena/ena_netdev.h  |   4 +
 drivers/net/ethernet/amazon/ena/ena_phc.c     | 223 +++++++++++++++
 drivers/net/ethernet/amazon/ena/ena_phc.h     |  37 +++
 .../net/ethernet/amazon/ena/ena_regs_defs.h   |   8 +
 12 files changed, 736 insertions(+), 5 deletions(-)
 create mode 100644 drivers/net/ethernet/amazon/ena/ena_phc.c
 create mode 100644 drivers/net/ethernet/amazon/ena/ena_phc.h

diff --git a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
index 4561e8ab9e08..98dc62174a40 100644
--- a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
+++ b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
@@ -56,6 +56,7 @@ ena_netdev.[ch]     Main Linux kernel driver.
 ena_ethtool.c       ethtool callbacks.
 ena_xdp.[ch]        XDP files
 ena_pci_id_tbl.h    Supported device IDs.
+ena_phc.[ch]        PTP hardware clock infrastructure (see `PHC`_ for more info)
 =================   ======================================================
 
 Management Interface:
diff --git a/drivers/net/ethernet/amazon/Kconfig b/drivers/net/ethernet/amazon/Kconfig
index c37fa393b99e..8d61bc62e295 100644
--- a/drivers/net/ethernet/amazon/Kconfig
+++ b/drivers/net/ethernet/amazon/Kconfig
@@ -19,6 +19,7 @@ if NET_VENDOR_AMAZON
 config ENA_ETHERNET
 	tristate "Elastic Network Adapter (ENA) support"
 	depends on PCI_MSI && !CPU_BIG_ENDIAN
+	depends on PTP_1588_CLOCK_OPTIONAL
 	select DIMLIB
 	help
 	  This driver supports Elastic Network Adapter (ENA)"
diff --git a/drivers/net/ethernet/amazon/ena/Makefile b/drivers/net/ethernet/amazon/ena/Makefile
index 6ab615365172..8c874177468f 100644
--- a/drivers/net/ethernet/amazon/ena/Makefile
+++ b/drivers/net/ethernet/amazon/ena/Makefile
@@ -5,4 +5,4 @@
 
 obj-$(CONFIG_ENA_ETHERNET) += ena.o
 
-ena-y := ena_netdev.o ena_com.o ena_eth_com.o ena_ethtool.o ena_xdp.o
+ena-y := ena_netdev.o ena_com.o ena_eth_com.o ena_ethtool.o ena_xdp.o ena_phc.o
diff --git a/drivers/net/ethernet/amazon/ena/ena_admin_defs.h b/drivers/net/ethernet/amazon/ena/ena_admin_defs.h
index 9d9fa6559354..562869a0fdba 100644
--- a/drivers/net/ethernet/amazon/ena/ena_admin_defs.h
+++ b/drivers/net/ethernet/amazon/ena/ena_admin_defs.h
@@ -60,6 +60,7 @@ enum ena_admin_aq_feature_id {
 	ENA_ADMIN_AENQ_CONFIG                       = 26,
 	ENA_ADMIN_LINK_CONFIG                       = 27,
 	ENA_ADMIN_HOST_ATTR_CONFIG                  = 28,
+	ENA_ADMIN_PHC_CONFIG                        = 29,
 	ENA_ADMIN_FEATURES_OPCODE_NUM               = 32,
 };
 
@@ -127,6 +128,14 @@ enum ena_admin_get_stats_scope {
 	ENA_ADMIN_ETH_TRAFFIC                       = 1,
 };
 
+enum ena_admin_phc_type {
+	ENA_ADMIN_PHC_TYPE_READLESS                 = 0,
+};
+
+enum ena_admin_phc_error_flags {
+	ENA_ADMIN_PHC_ERROR_FLAG_TIMESTAMP   = BIT(0),
+};
+
 /* ENA SRD configuration for ENI */
 enum ena_admin_ena_srd_flags {
 	/* Feature enabled */
@@ -943,7 +952,9 @@ struct ena_admin_host_info {
 	 * 4 : rss_configurable_function_key
 	 * 5 : reserved
 	 * 6 : rx_page_reuse
-	 * 31:7 : reserved
+	 * 7 : reserved
+	 * 8 : phc
+	 * 31:9 : reserved
 	 */
 	u32 driver_supported_features;
 };
@@ -1023,6 +1034,43 @@ struct ena_admin_queue_ext_feature_desc {
 	};
 };
 
+struct ena_admin_feature_phc_desc {
+	/* PHC type as defined in enum ena_admin_get_phc_type,
+	 * used only for GET command.
+	 */
+	u8 type;
+
+	/* Reserved - MBZ */
+	u8 reserved1[3];
+
+	/* PHC doorbell address as an offset to PCIe MMIO REG BAR,
+	 * used only for GET command.
+	 */
+	u32 doorbell_offset;
+
+	/* Max time for valid PHC retrieval, passing this threshold will
+	 * fail the get-time request and block PHC requests for
+	 * block_timeout_usec, used only for GET command.
+	 */
+	u32 expire_timeout_usec;
+
+	/* PHC requests block period, blocking starts if PHC request expired
+	 * in order to prevent floods on busy device,
+	 * used only for GET command.
+	 */
+	u32 block_timeout_usec;
+
+	/* Shared PHC physical address (ena_admin_phc_resp),
+	 * used only for SET command.
+	 */
+	struct ena_common_mem_addr output_address;
+
+	/* Shared PHC Size (ena_admin_phc_resp),
+	 * used only for SET command.
+	 */
+	u32 output_length;
+};
+
 struct ena_admin_get_feat_resp {
 	struct ena_admin_acq_common_desc acq_common_desc;
 
@@ -1052,6 +1100,8 @@ struct ena_admin_get_feat_resp {
 		struct ena_admin_feature_intr_moder_desc intr_moderation;
 
 		struct ena_admin_ena_hw_hints hw_hints;
+
+		struct ena_admin_feature_phc_desc phc;
 	} u;
 };
 
@@ -1085,6 +1135,9 @@ struct ena_admin_set_feat_cmd {
 
 		/* LLQ configuration */
 		struct ena_admin_feature_llq_desc llq;
+
+		/* PHC configuration */
+		struct ena_admin_feature_phc_desc phc;
 	} u;
 };
 
@@ -1162,6 +1215,23 @@ struct ena_admin_ena_mmio_req_read_less_resp {
 	u32 reg_val;
 };
 
+struct ena_admin_phc_resp {
+	/* Request Id, received from DB register */
+	u16 req_id;
+
+	u8 reserved1[6];
+
+	/* PHC timestamp (nsec) */
+	u64 timestamp;
+
+	u8 reserved2[12];
+
+	/* Bit field of enum ena_admin_phc_error_flags */
+	u32 error_flags;
+
+	u8 reserved3[32];
+};
+
 /* aq_common_desc */
 #define ENA_ADMIN_AQ_COMMON_DESC_COMMAND_ID_MASK            GENMASK(11, 0)
 #define ENA_ADMIN_AQ_COMMON_DESC_PHASE_MASK                 BIT(0)
@@ -1260,6 +1330,8 @@ struct ena_admin_ena_mmio_req_read_less_resp {
 #define ENA_ADMIN_HOST_INFO_RSS_CONFIGURABLE_FUNCTION_KEY_MASK BIT(4)
 #define ENA_ADMIN_HOST_INFO_RX_PAGE_REUSE_SHIFT             6
 #define ENA_ADMIN_HOST_INFO_RX_PAGE_REUSE_MASK              BIT(6)
+#define ENA_ADMIN_HOST_INFO_PHC_SHIFT                       8
+#define ENA_ADMIN_HOST_INFO_PHC_MASK                        BIT(8)
 
 /* aenq_common_desc */
 #define ENA_ADMIN_AENQ_COMMON_DESC_PHASE_MASK               BIT(0)
diff --git a/drivers/net/ethernet/amazon/ena/ena_com.c b/drivers/net/ethernet/amazon/ena/ena_com.c
index 66445617fbfb..e67b592e5697 100644
--- a/drivers/net/ethernet/amazon/ena/ena_com.c
+++ b/drivers/net/ethernet/amazon/ena/ena_com.c
@@ -41,6 +41,12 @@
 
 #define ENA_MAX_ADMIN_POLL_US 5000
 
+/* PHC definitions */
+#define ENA_PHC_DEFAULT_EXPIRE_TIMEOUT_USEC 10
+#define ENA_PHC_DEFAULT_BLOCK_TIMEOUT_USEC 1000
+#define ENA_PHC_REQ_ID_OFFSET 0xDEAD
+#define ENA_PHC_ERROR_FLAGS (ENA_ADMIN_PHC_ERROR_FLAG_TIMESTAMP)
+
 /*****************************************************************************/
 /*****************************************************************************/
 /*****************************************************************************/
@@ -1641,6 +1647,267 @@ void ena_com_set_admin_polling_mode(struct ena_com_dev *ena_dev, bool polling)
 	ena_dev->admin_queue.polling = polling;
 }
 
+bool ena_com_phc_supported(struct ena_com_dev *ena_dev)
+{
+	return ena_com_check_supported_feature_id(ena_dev, ENA_ADMIN_PHC_CONFIG);
+}
+
+int ena_com_phc_init(struct ena_com_dev *ena_dev)
+{
+	struct ena_com_phc_info *phc = &ena_dev->phc;
+
+	memset(phc, 0x0, sizeof(*phc));
+
+	/* Allocate shared mem used PHC timestamp retrieved from device */
+	phc->virt_addr = dma_alloc_coherent(ena_dev->dmadev,
+					    sizeof(*phc->virt_addr),
+					    &phc->phys_addr,
+					    GFP_KERNEL);
+	if (unlikely(!phc->virt_addr))
+		return -ENOMEM;
+
+	spin_lock_init(&phc->lock);
+
+	phc->virt_addr->req_id = 0;
+	phc->virt_addr->timestamp = 0;
+
+	return 0;
+}
+
+int ena_com_phc_config(struct ena_com_dev *ena_dev)
+{
+	struct ena_com_phc_info *phc = &ena_dev->phc;
+	struct ena_admin_get_feat_resp get_feat_resp;
+	struct ena_admin_set_feat_resp set_feat_resp;
+	struct ena_admin_set_feat_cmd set_feat_cmd;
+	int ret = 0;
+
+	/* Get device PHC default configuration */
+	ret = ena_com_get_feature(ena_dev,
+				  &get_feat_resp,
+				  ENA_ADMIN_PHC_CONFIG,
+				  0);
+	if (unlikely(ret)) {
+		netdev_err(ena_dev->net_device,
+			   "Failed to get PHC feature configuration, error: %d\n",
+			   ret);
+		return ret;
+	}
+
+	/* Supporting only readless PHC retrieval */
+	if (get_feat_resp.u.phc.type != ENA_ADMIN_PHC_TYPE_READLESS) {
+		netdev_err(ena_dev->net_device,
+			   "Unsupported PHC type, error: %d\n",
+			   -EOPNOTSUPP);
+		return -EOPNOTSUPP;
+	}
+
+	/* Update PHC doorbell offset according to device value,
+	 * used to write req_id to PHC bar
+	 */
+	phc->doorbell_offset = get_feat_resp.u.phc.doorbell_offset;
+
+	/* Update PHC expire timeout according to device
+	 * or default driver value
+	 */
+	phc->expire_timeout_usec = (get_feat_resp.u.phc.expire_timeout_usec) ?
+				    get_feat_resp.u.phc.expire_timeout_usec :
+				    ENA_PHC_DEFAULT_EXPIRE_TIMEOUT_USEC;
+
+	/* Update PHC block timeout according to device
+	 * or default driver value
+	 */
+	phc->block_timeout_usec = (get_feat_resp.u.phc.block_timeout_usec) ?
+				   get_feat_resp.u.phc.block_timeout_usec :
+				   ENA_PHC_DEFAULT_BLOCK_TIMEOUT_USEC;
+
+	/* Sanity check - expire timeout must not exceed block timeout */
+	if (phc->expire_timeout_usec > phc->block_timeout_usec)
+		phc->expire_timeout_usec = phc->block_timeout_usec;
+
+	/* Prepare PHC feature command */
+	memset(&set_feat_cmd, 0x0, sizeof(set_feat_cmd));
+	set_feat_cmd.aq_common_descriptor.opcode = ENA_ADMIN_SET_FEATURE;
+	set_feat_cmd.feat_common.feature_id = ENA_ADMIN_PHC_CONFIG;
+	set_feat_cmd.u.phc.output_length = sizeof(*phc->virt_addr);
+	ret = ena_com_mem_addr_set(ena_dev,
+				   &set_feat_cmd.u.phc.output_address,
+				   phc->phys_addr);
+	if (unlikely(ret)) {
+		netdev_err(ena_dev->net_device,
+			   "Failed setting PHC output address, error: %d\n",
+			   ret);
+		return ret;
+	}
+
+	/* Send PHC feature command to the device */
+	ret = ena_com_execute_admin_command(&ena_dev->admin_queue,
+					    (struct ena_admin_aq_entry *)&set_feat_cmd,
+					    sizeof(set_feat_cmd),
+					    (struct ena_admin_acq_entry *)&set_feat_resp,
+					    sizeof(set_feat_resp));
+
+	if (unlikely(ret)) {
+		netdev_err(ena_dev->net_device,
+			   "Failed to enable PHC, error: %d\n",
+			   ret);
+		return ret;
+	}
+
+	phc->active = true;
+	netdev_dbg(ena_dev->net_device, "PHC is active in the device\n");
+
+	return ret;
+}
+
+void ena_com_phc_destroy(struct ena_com_dev *ena_dev)
+{
+	struct ena_com_phc_info *phc = &ena_dev->phc;
+	unsigned long flags = 0;
+
+	/* In case PHC is not supported by the device, silently exiting */
+	if (!phc->virt_addr)
+		return;
+
+	spin_lock_irqsave(&phc->lock, flags);
+	phc->active = false;
+	spin_unlock_irqrestore(&phc->lock, flags);
+
+	dma_free_coherent(ena_dev->dmadev,
+			  sizeof(*phc->virt_addr),
+			  phc->virt_addr,
+			  phc->phys_addr);
+	phc->virt_addr = NULL;
+}
+
+int ena_com_phc_get_timestamp(struct ena_com_dev *ena_dev, u64 *timestamp)
+{
+	volatile struct ena_admin_phc_resp *resp = ena_dev->phc.virt_addr;
+	const ktime_t zero_system_time = ktime_set(0, 0);
+	struct ena_com_phc_info *phc = &ena_dev->phc;
+	ktime_t expire_time;
+	ktime_t block_time;
+	unsigned long flags = 0;
+	int ret = 0;
+
+	if (!phc->active) {
+		netdev_err(ena_dev->net_device, "PHC feature is not active in the device\n");
+		return -EOPNOTSUPP;
+	}
+
+	spin_lock_irqsave(&phc->lock, flags);
+
+	/* Check if PHC is in blocked state */
+	if (unlikely(ktime_compare(phc->system_time, zero_system_time))) {
+		/* Check if blocking time expired */
+		block_time = ktime_add_us(phc->system_time, phc->block_timeout_usec);
+		if (!ktime_after(ktime_get(), block_time)) {
+			/* PHC is still in blocked state, skip PHC request */
+			phc->stats.phc_skp++;
+			ret = -EBUSY;
+			goto skip;
+		}
+
+		/* PHC is in active state, update statistics according
+		 * to req_id and error_flags
+		 */
+		if (READ_ONCE(resp->req_id) != phc->req_id) {
+			/* Device didn't update req_id during blocking time,
+			 * this indicates on a device error
+			 */
+			netdev_err(ena_dev->net_device,
+				   "PHC get time request 0x%x failed (device error)\n",
+				   phc->req_id);
+			phc->stats.phc_err_dv++;
+		} else if (resp->error_flags & ENA_PHC_ERROR_FLAGS) {
+			/* Device updated req_id during blocking time but got
+			 * a PHC error, this occurs if device:
+			 * - exceeded the get time request limit
+			 * - received an invalid timestamp
+			 */
+			netdev_err(ena_dev->net_device,
+				   "PHC get time request 0x%x failed (error 0x%x)\n",
+				   phc->req_id,
+				   resp->error_flags);
+			phc->stats.phc_err_ts += !!(resp->error_flags &
+				ENA_ADMIN_PHC_ERROR_FLAG_TIMESTAMP);
+		} else {
+			/* Device updated req_id during blocking time
+			 * with valid timestamp
+			 */
+			phc->stats.phc_exp++;
+		}
+	}
+
+	/* Setting relative timeouts */
+	phc->system_time = ktime_get();
+	block_time = ktime_add_us(phc->system_time, phc->block_timeout_usec);
+	expire_time = ktime_add_us(phc->system_time, phc->expire_timeout_usec);
+
+	/* We expect the device to return this req_id once
+	 * the new PHC timestamp is updated
+	 */
+	phc->req_id++;
+
+	/* Initialize PHC shared memory with different req_id value
+	 * to be able to identify once the device changes it to req_id
+	 */
+	resp->req_id = phc->req_id + ENA_PHC_REQ_ID_OFFSET;
+
+	/* Writing req_id to PHC bar */
+	writel(phc->req_id, ena_dev->reg_bar + phc->doorbell_offset);
+
+	/* Stalling until the device updates req_id */
+	while (1) {
+		if (unlikely(ktime_after(ktime_get(), expire_time))) {
+			/* Gave up waiting for updated req_id, PHC enters into
+			 * blocked state until passing blocking time,
+			 * during this time any get PHC timestamp will fail with
+			 * device busy error
+			 */
+			ret = -EBUSY;
+			break;
+		}
+
+		/* Check if req_id was updated by the device */
+		if (READ_ONCE(resp->req_id) != phc->req_id) {
+			/* req_id was not updated by the device yet,
+			 * check again on next loop
+			 */
+			continue;
+		}
+
+		/* req_id was updated by the device which indicates that
+		 * PHC timestamp and error_flags are updated too,
+		 * checking errors before retrieving timestamp
+		 */
+		if (unlikely(resp->error_flags & ENA_PHC_ERROR_FLAGS)) {
+			/* Retrieved invalid PHC timestamp, PHC enters into
+			 * blocked state until passing blocking time,
+			 * during this time any get PHC timestamp requests
+			 * will fail with device busy error
+			 */
+			ret = -EBUSY;
+			break;
+		}
+
+		/* PHC timestamp value is returned to the caller */
+		*timestamp = resp->timestamp;
+
+		/* Update statistic on valid PHC timestamp retrieval */
+		phc->stats.phc_cnt++;
+
+		/* This indicates PHC state is active */
+		phc->system_time = zero_system_time;
+		break;
+	}
+
+skip:
+	spin_unlock_irqrestore(&phc->lock, flags);
+
+	return ret;
+}
+
 int ena_com_mmio_reg_read_request_init(struct ena_com_dev *ena_dev)
 {
 	struct ena_com_mmio_read *mmio_read = &ena_dev->mmio_read;
diff --git a/drivers/net/ethernet/amazon/ena/ena_com.h b/drivers/net/ethernet/amazon/ena/ena_com.h
index 9414e93d107b..64df2c48c9a6 100644
--- a/drivers/net/ethernet/amazon/ena/ena_com.h
+++ b/drivers/net/ethernet/amazon/ena/ena_com.h
@@ -210,6 +210,14 @@ struct ena_com_stats_admin {
 	u64 no_completion;
 };
 
+struct ena_com_stats_phc {
+	u64 phc_cnt;
+	u64 phc_exp;
+	u64 phc_skp;
+	u64 phc_err_dv;
+	u64 phc_err_ts;
+};
+
 struct ena_com_admin_queue {
 	void *q_dmadev;
 	struct ena_com_dev *ena_dev;
@@ -258,6 +266,47 @@ struct ena_com_mmio_read {
 	spinlock_t lock;
 };
 
+/* PTP hardware clock (PHC) MMIO read data info */
+struct ena_com_phc_info {
+	/* Internal PHC statistics */
+	struct ena_com_stats_phc stats;
+
+	/* PHC shared memory - virtual address */
+	struct ena_admin_phc_resp *virt_addr;
+
+	/* System time of last PHC request */
+	ktime_t system_time;
+
+	/* Spin lock to ensure a single outstanding PHC read */
+	spinlock_t lock;
+
+	/* PHC doorbell address as an offset to PCIe MMIO REG BAR */
+	u32 doorbell_offset;
+
+	/* Shared memory read expire timeout (usec)
+	 * Max time for valid PHC retrieval, passing this threshold will fail
+	 * the get time request and block new PHC requests for block_timeout_usec
+	 * in order to prevent floods on busy device
+	 */
+	u32 expire_timeout_usec;
+
+	/* Shared memory read abort timeout (usec)
+	 * PHC requests block period, blocking starts once PHC request expired
+	 * in order to prevent floods on busy device,
+	 * any PHC requests during block period will be skipped
+	 */
+	u32 block_timeout_usec;
+
+	/* PHC shared memory - physical address */
+	dma_addr_t phys_addr;
+
+	/* Request id sent to the device */
+	u16 req_id;
+
+	/* True if PHC is active in the device */
+	bool active;
+};
+
 struct ena_rss {
 	/* Indirect table */
 	u16 *host_rss_ind_tbl;
@@ -317,6 +366,7 @@ struct ena_com_dev {
 	u32 ena_min_poll_delay_us;
 
 	struct ena_com_mmio_read mmio_read;
+	struct ena_com_phc_info phc;
 
 	struct ena_rss rss;
 	u32 supported_features;
@@ -382,6 +432,40 @@ struct ena_aenq_handlers {
  */
 int ena_com_mmio_reg_read_request_init(struct ena_com_dev *ena_dev);
 
+/* ena_com_phc_init - Allocate and initialize PHC feature
+ * @ena_dev: ENA communication layer struct
+ * @note: This method assumes PHC is supported by the device
+ * @return - 0 on success, negative value on failure
+ */
+int ena_com_phc_init(struct ena_com_dev *ena_dev);
+
+/* ena_com_phc_supported - Return if PHC feature is supported by the device
+ * @ena_dev: ENA communication layer struct
+ * @note: This method must be called after getting supported features
+ * @return - supported or not
+ */
+bool ena_com_phc_supported(struct ena_com_dev *ena_dev);
+
+/* ena_com_phc_config - Configure PHC feature
+ * @ena_dev: ENA communication layer struct
+ * Configure PHC feature in driver and device
+ * @note: This method assumes PHC is supported by the device
+ * @return - 0 on success, negative value on failure
+ */
+int ena_com_phc_config(struct ena_com_dev *ena_dev);
+
+/* ena_com_phc_destroy - Destroy PHC feature
+ * @ena_dev: ENA communication layer struct
+ */
+void ena_com_phc_destroy(struct ena_com_dev *ena_dev);
+
+/* ena_com_phc_get_timestamp - Retrieve PHC timestamp
+ * @ena_dev: ENA communication layer struct
+ * @timestamp: Retrieved PHC timestamp
+ * @return - 0 on success, negative value on failure
+ */
+int ena_com_phc_get_timestamp(struct ena_com_dev *ena_dev, u64 *timestamp);
+
 /* ena_com_set_mmio_read_mode - Enable/disable the indirect mmio reg read mechanism
  * @ena_dev: ENA communication layer struct
  * @readless_supported: readless mode (enable/disable)
diff --git a/drivers/net/ethernet/amazon/ena/ena_ethtool.c b/drivers/net/ethernet/amazon/ena/ena_ethtool.c
index 07e8f6b1e8af..a81d3a7a3bb9 100644
--- a/drivers/net/ethernet/amazon/ena/ena_ethtool.c
+++ b/drivers/net/ethernet/amazon/ena/ena_ethtool.c
@@ -5,9 +5,11 @@
 
 #include <linux/ethtool.h>
 #include <linux/pci.h>
+#include <linux/net_tstamp.h>
 
 #include "ena_netdev.h"
 #include "ena_xdp.h"
+#include "ena_phc.h"
 
 struct ena_stats {
 	char name[ETH_GSTRING_LEN];
@@ -298,6 +300,18 @@ static void ena_get_ethtool_stats(struct net_device *netdev,
 	ena_get_stats(adapter, data, true);
 }
 
+static int ena_get_ts_info(struct net_device *netdev,
+			   struct kernel_ethtool_ts_info *info)
+{
+	struct ena_adapter *adapter = netdev_priv(netdev);
+
+	info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE;
+
+	info->phc_index = ena_phc_get_index(adapter);
+
+	return 0;
+}
+
 static int ena_get_sw_stats_count(struct ena_adapter *adapter)
 {
 	return adapter->num_io_queues * (ENA_STATS_ARRAY_TX + ENA_STATS_ARRAY_RX)
@@ -1090,7 +1104,7 @@ static const struct ethtool_ops ena_ethtool_ops = {
 	.set_channels		= ena_set_channels,
 	.get_tunable		= ena_get_tunable,
 	.set_tunable		= ena_set_tunable,
-	.get_ts_info            = ethtool_op_get_ts_info,
+	.get_ts_info		= ena_get_ts_info,
 };
 
 void ena_set_ethtool_ops(struct net_device *netdev)
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 86fd08f375df..14a85916464b 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -19,6 +19,8 @@
 #include "ena_pci_id_tbl.h"
 #include "ena_xdp.h"
 
+#include "ena_phc.h"
+
 MODULE_AUTHOR("Amazon.com, Inc. or its affiliates");
 MODULE_DESCRIPTION(DEVICE_NAME);
 MODULE_LICENSE("GPL");
@@ -2743,7 +2745,8 @@ static void ena_config_host_info(struct ena_com_dev *ena_dev, struct pci_dev *pd
 		ENA_ADMIN_HOST_INFO_INTERRUPT_MODERATION_MASK |
 		ENA_ADMIN_HOST_INFO_RX_BUF_MIRRORING_MASK |
 		ENA_ADMIN_HOST_INFO_RSS_CONFIGURABLE_FUNCTION_KEY_MASK |
-		ENA_ADMIN_HOST_INFO_RX_PAGE_REUSE_MASK;
+		ENA_ADMIN_HOST_INFO_RX_PAGE_REUSE_MASK |
+		ENA_ADMIN_HOST_INFO_PHC_MASK;
 
 	rc = ena_com_set_host_attributes(ena_dev);
 	if (rc) {
@@ -3188,6 +3191,10 @@ static int ena_device_init(struct ena_adapter *adapter, struct pci_dev *pdev,
 	if (unlikely(rc))
 		goto err_admin_init;
 
+	rc = ena_phc_init(adapter);
+	if (unlikely(rc && (rc != -EOPNOTSUPP)))
+		netdev_err(netdev, "Failed initializing PHC, error: %d\n", rc);
+
 	return 0;
 
 err_admin_init:
@@ -3271,6 +3278,8 @@ static int ena_destroy_device(struct ena_adapter *adapter, bool graceful)
 
 	ena_com_admin_destroy(ena_dev);
 
+	ena_phc_destroy(adapter);
+
 	ena_com_mmio_reg_read_request_destroy(ena_dev);
 
 	/* return reset reason to default value */
@@ -3344,6 +3353,7 @@ static int ena_restore_device(struct ena_adapter *adapter)
 	ena_com_wait_for_abort_completion(ena_dev);
 	ena_com_admin_destroy(ena_dev);
 	ena_com_dev_reset(ena_dev, ENA_REGS_RESET_DRIVER_INVALID_STATE);
+	ena_phc_destroy(adapter);
 	ena_com_mmio_reg_read_request_destroy(ena_dev);
 err:
 	clear_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags);
@@ -3932,10 +3942,16 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	pci_set_drvdata(pdev, adapter);
 
+	rc = ena_phc_alloc(adapter);
+	if (rc) {
+		netdev_err(netdev, "ena_phc_alloc failed\n");
+		goto err_netdev_destroy;
+	}
+
 	rc = ena_com_allocate_customer_metrics_buffer(ena_dev);
 	if (rc) {
 		netdev_err(netdev, "ena_com_allocate_customer_metrics_buffer failed\n");
-		goto err_netdev_destroy;
+		goto err_free_phc;
 	}
 
 	rc = ena_map_llq_mem_bar(pdev, ena_dev, bars);
@@ -4072,6 +4088,8 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	ena_com_admin_destroy(ena_dev);
 err_metrics_destroy:
 	ena_com_delete_customer_metrics_buffer(ena_dev);
+err_free_phc:
+	ena_phc_free(adapter);
 err_netdev_destroy:
 	free_netdev(netdev);
 err_free_region:
@@ -4112,6 +4130,8 @@ static void __ena_shutoff(struct pci_dev *pdev, bool shutdown)
 	adapter->reset_reason = ENA_REGS_RESET_SHUTDOWN;
 	ena_destroy_device(adapter, true);
 
+	ena_phc_free(adapter);
+
 	if (shutdown) {
 		netif_device_detach(netdev);
 		dev_close(netdev);
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h
index 6e12ae3b12e5..7867cd7f25bc 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.h
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h
@@ -110,6 +110,8 @@
 
 #define ENA_MMIO_DISABLE_REG_READ	BIT(0)
 
+struct ena_phc_info;
+
 struct ena_irq {
 	irq_handler_t handler;
 	void *data;
@@ -348,6 +350,8 @@ struct ena_adapter {
 
 	char name[ENA_NAME_MAX_LEN];
 
+	struct ena_phc_info *phc_info;
+
 	unsigned long flags;
 	/* TX */
 	struct ena_ring tx_ring[ENA_MAX_NUM_IO_QUEUES]
diff --git a/drivers/net/ethernet/amazon/ena/ena_phc.c b/drivers/net/ethernet/amazon/ena/ena_phc.c
new file mode 100644
index 000000000000..612cf45e3a9b
--- /dev/null
+++ b/drivers/net/ethernet/amazon/ena/ena_phc.c
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/*
+ * Copyright 2015-2022 Amazon.com, Inc. or its affiliates. All rights reserved.
+ */
+
+#include <linux/pci.h>
+#include "ena_netdev.h"
+#include "ena_phc.h"
+
+static int ena_phc_adjtime(struct ptp_clock_info *clock_info, s64 delta)
+{
+	return -EOPNOTSUPP;
+}
+
+static int ena_phc_adjfine(struct ptp_clock_info *clock_info, long scaled_ppm)
+{
+	return -EOPNOTSUPP;
+}
+
+static int ena_phc_feature_enable(struct ptp_clock_info *clock_info,
+				  struct ptp_clock_request *rq,
+				  int on)
+{
+	return -EOPNOTSUPP;
+}
+
+static int ena_phc_gettimex64(struct ptp_clock_info *clock_info,
+			      struct timespec64 *ts,
+			      struct ptp_system_timestamp *sts)
+{
+	struct ena_phc_info *phc_info =
+		container_of(clock_info, struct ena_phc_info, clock_info);
+	unsigned long flags;
+	u64 timestamp_nsec;
+	int rc;
+
+	spin_lock_irqsave(&phc_info->lock, flags);
+
+	ptp_read_system_prets(sts);
+
+	rc = ena_com_phc_get_timestamp(phc_info->adapter->ena_dev,
+				       &timestamp_nsec);
+
+	ptp_read_system_postts(sts);
+
+	spin_unlock_irqrestore(&phc_info->lock, flags);
+
+	*ts = ns_to_timespec64(timestamp_nsec);
+
+	return rc;
+}
+
+static int ena_phc_settime64(struct ptp_clock_info *clock_info,
+			     const struct timespec64 *ts)
+{
+	return -EOPNOTSUPP;
+}
+
+static struct ptp_clock_info ena_ptp_clock_info = {
+	.owner		= THIS_MODULE,
+	.n_alarm	= 0,
+	.n_ext_ts	= 0,
+	.n_per_out	= 0,
+	.pps		= 0,
+	.adjtime	= ena_phc_adjtime,
+	.adjfine	= ena_phc_adjfine,
+	.gettimex64	= ena_phc_gettimex64,
+	.settime64	= ena_phc_settime64,
+	.enable		= ena_phc_feature_enable,
+};
+
+/* Enable/Disable PHC by the kernel, affects on the next init flow */
+void ena_phc_enable(struct ena_adapter *adapter, bool enable)
+{
+	struct ena_phc_info *phc_info = adapter->phc_info;
+
+	if (!phc_info) {
+		netdev_err(adapter->netdev, "phc_info is not allocated\n");
+		return;
+	}
+
+	phc_info->enabled = enable;
+}
+
+/* Check if PHC is enabled by the kernel */
+bool ena_phc_is_enabled(struct ena_adapter *adapter)
+{
+	struct ena_phc_info *phc_info = adapter->phc_info;
+
+	return (phc_info && phc_info->enabled);
+}
+
+/* PHC is activated if ptp clock is registered in the kernel */
+bool ena_phc_is_active(struct ena_adapter *adapter)
+{
+	struct ena_phc_info *phc_info = adapter->phc_info;
+
+	return (phc_info && phc_info->clock);
+}
+
+static int ena_phc_register(struct ena_adapter *adapter)
+{
+	struct pci_dev *pdev = adapter->pdev;
+	struct ptp_clock_info *clock_info;
+	struct ena_phc_info *phc_info;
+	int rc = 0;
+
+	phc_info = adapter->phc_info;
+	clock_info = &phc_info->clock_info;
+
+	phc_info->adapter = adapter;
+
+	spin_lock_init(&phc_info->lock);
+
+	/* Fill the ptp_clock_info struct and register PTP clock */
+	*clock_info = ena_ptp_clock_info;
+	snprintf(clock_info->name,
+		 sizeof(clock_info->name),
+		 "ena-ptp-%02x",
+		 PCI_SLOT(pdev->devfn));
+
+	phc_info->clock = ptp_clock_register(clock_info, &pdev->dev);
+	if (IS_ERR(phc_info->clock)) {
+		rc = PTR_ERR(phc_info->clock);
+		netdev_err(adapter->netdev, "Failed registering ptp clock, error: %d\n",
+			   rc);
+		phc_info->clock = NULL;
+	}
+
+	return rc;
+}
+
+static void ena_phc_unregister(struct ena_adapter *adapter)
+{
+	struct ena_phc_info *phc_info = adapter->phc_info;
+
+	if (ena_phc_is_active(adapter)) {
+		ptp_clock_unregister(phc_info->clock);
+		phc_info->clock = NULL;
+	}
+}
+
+int ena_phc_alloc(struct ena_adapter *adapter)
+{
+	/* Allocate driver specific PHC info */
+	adapter->phc_info = vzalloc(sizeof(*adapter->phc_info));
+	if (unlikely(!adapter->phc_info)) {
+		netdev_err(adapter->netdev, "Failed to alloc phc_info\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void ena_phc_free(struct ena_adapter *adapter)
+{
+	if (adapter->phc_info) {
+		vfree(adapter->phc_info);
+		adapter->phc_info = NULL;
+	}
+}
+
+int ena_phc_init(struct ena_adapter *adapter)
+{
+	struct ena_com_dev *ena_dev = adapter->ena_dev;
+	struct net_device *netdev = adapter->netdev;
+	int rc = -EOPNOTSUPP;
+
+	/* Validate PHC feature is supported in the device */
+	if (!ena_com_phc_supported(ena_dev)) {
+		netdev_dbg(netdev, "PHC feature is not supported by the device\n");
+		goto err_ena_com_phc_init;
+	}
+
+	/* Validate PHC feature is enabled by the kernel */
+	if (!ena_phc_is_enabled(adapter)) {
+		netdev_dbg(netdev, "PHC feature is not enabled by the kernel\n");
+		goto err_ena_com_phc_init;
+	}
+
+	/* Initialize device specific PHC info */
+	rc = ena_com_phc_init(ena_dev);
+	if (unlikely(rc)) {
+		netdev_err(netdev, "Failed to init phc, error: %d\n", rc);
+		goto err_ena_com_phc_init;
+	}
+
+	/* Configure PHC feature in driver and device */
+	rc = ena_com_phc_config(ena_dev);
+	if (unlikely(rc)) {
+		netdev_err(netdev, "Failed to config phc, error: %d\n", rc);
+		goto err_ena_com_phc_config;
+	}
+
+	/* Register to PTP class driver */
+	rc = ena_phc_register(adapter);
+	if (unlikely(rc)) {
+		netdev_err(netdev, "Failed to register phc, error: %d\n", rc);
+		goto err_ena_com_phc_config;
+	}
+
+	return 0;
+
+err_ena_com_phc_config:
+	ena_com_phc_destroy(ena_dev);
+err_ena_com_phc_init:
+	ena_phc_enable(adapter, false);
+	return rc;
+}
+
+void ena_phc_destroy(struct ena_adapter *adapter)
+{
+	ena_phc_unregister(adapter);
+	ena_com_phc_destroy(adapter->ena_dev);
+}
+
+int ena_phc_get_index(struct ena_adapter *adapter)
+{
+	if (ena_phc_is_active(adapter))
+		return ptp_clock_index(adapter->phc_info->clock);
+
+	return -1;
+}
diff --git a/drivers/net/ethernet/amazon/ena/ena_phc.h b/drivers/net/ethernet/amazon/ena/ena_phc.h
new file mode 100644
index 000000000000..7364fe714e44
--- /dev/null
+++ b/drivers/net/ethernet/amazon/ena/ena_phc.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/*
+ * Copyright 2015-2022 Amazon.com, Inc. or its affiliates. All rights reserved.
+ */
+
+#ifndef ENA_PHC_H
+#define ENA_PHC_H
+
+#include <linux/ptp_clock_kernel.h>
+
+struct ena_phc_info {
+	/* PTP hardware capabilities */
+	struct ptp_clock_info clock_info;
+
+	/* Registered PTP clock device */
+	struct ptp_clock *clock;
+
+	/* Adapter specific private data structure */
+	struct ena_adapter *adapter;
+
+	/* PHC lock */
+	spinlock_t lock;
+
+	/* Enabled by kernel */
+	bool enabled;
+};
+
+void ena_phc_enable(struct ena_adapter *adapter, bool enable);
+bool ena_phc_is_enabled(struct ena_adapter *adapter);
+bool ena_phc_is_active(struct ena_adapter *adapter);
+int ena_phc_get_index(struct ena_adapter *adapter);
+int ena_phc_init(struct ena_adapter *adapter);
+void ena_phc_destroy(struct ena_adapter *adapter);
+int ena_phc_alloc(struct ena_adapter *adapter);
+void ena_phc_free(struct ena_adapter *adapter);
+
+#endif /* ENA_PHC_H */
diff --git a/drivers/net/ethernet/amazon/ena/ena_regs_defs.h b/drivers/net/ethernet/amazon/ena/ena_regs_defs.h
index a2efebafd686..51068dc1cc2a 100644
--- a/drivers/net/ethernet/amazon/ena/ena_regs_defs.h
+++ b/drivers/net/ethernet/amazon/ena/ena_regs_defs.h
@@ -53,6 +53,11 @@ enum ena_regs_reset_reason_types {
 #define ENA_REGS_MMIO_RESP_HI_OFF                           0x64
 #define ENA_REGS_RSS_IND_ENTRY_UPDATE_OFF                   0x68
 
+/* phc_registers offsets */
+
+/* 100 base */
+#define ENA_REGS_PHC_DB_OFF                                 0x100
+
 /* version register */
 #define ENA_REGS_VERSION_MINOR_VERSION_MASK                 0xff
 #define ENA_REGS_VERSION_MAJOR_VERSION_SHIFT                8
@@ -129,4 +134,7 @@ enum ena_regs_reset_reason_types {
 #define ENA_REGS_RSS_IND_ENTRY_UPDATE_CQ_IDX_SHIFT          16
 #define ENA_REGS_RSS_IND_ENTRY_UPDATE_CQ_IDX_MASK           0xffff0000
 
+/* phc_db_req_id register */
+#define ENA_REGS_PHC_DB_REQ_ID_MASK                         0xffff
+
 #endif /* _ENA_REGS_H_ */

From 51d58804a53b341b785f9856d9ffec45e72108a3 Mon Sep 17 00:00:00 2001
From: David Arinzon <darinzon@amazon.com>
Date: Tue, 17 Jun 2025 14:05:38 +0300
Subject: [PATCH 2/9] net: ena: PHC silent reset
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Each PHC device kernel registration receives a unique kernel index,
which is associated with a new PHC device file located at
"/dev/ptp<index>".
This device file serves as an interface for obtaining PHC timestamps.
Examples of tools that use "/dev/ptp" include testptp [1]
and chrony [2].

A reset flow may occur in the ENA driver while PHC is active.
During a reset, the driver will unregister and then re-register the
PHC device with the kernel.
Under race conditions, particularly during heavy PHC loads,
the driver’s reset flow might complete faster than the kernel’s PHC
unregister/register process.
This can result in the PHC index being different from what it was prior
to the reset, as the PHC index is selected using kernel ID
allocation [3].

While driver rmmod/insmod are done by the user, a reset may occur
at anytime, without the user awareness, consequently, the driver
might receive a new PHC index after the reset, potentially compromising
the user experience.

To prevent this issue, the PHC flow will detect the reset during PHC
destruction and will skip the PHC unregister/register calls to preserve
the kernel PHC index.
During the reset flow, any attempt to get a PHC timestamp will fail as
expected, but the kernel PHC index will remain unchanged.

[1]: https://github.com/torvalds/linux/blob/v6.1/tools/testing/selftests/ptp/testptp.c
[2]: https://github.com/mlichvar/chrony
[3]: https://www.kernel.org/doc/html/latest/core-api/idr.html

Signed-off-by: Amit Bernstein <amitbern@amazon.com>
Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://patch.msgid.link/20250617110545.5659-3-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/amazon/ena/ena_phc.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_phc.c b/drivers/net/ethernet/amazon/ena/ena_phc.c
index 612cf45e3a9b..5ce9a32d210a 100644
--- a/drivers/net/ethernet/amazon/ena/ena_phc.c
+++ b/drivers/net/ethernet/amazon/ena/ena_phc.c
@@ -108,6 +108,10 @@ static int ena_phc_register(struct ena_adapter *adapter)
 	phc_info = adapter->phc_info;
 	clock_info = &phc_info->clock_info;
 
+	/* PHC may already be registered in case of a reset */
+	if (ena_phc_is_active(adapter))
+		return 0;
+
 	phc_info->adapter = adapter;
 
 	spin_lock_init(&phc_info->lock);
@@ -134,7 +138,11 @@ static void ena_phc_unregister(struct ena_adapter *adapter)
 {
 	struct ena_phc_info *phc_info = adapter->phc_info;
 
-	if (ena_phc_is_active(adapter)) {
+	/* During reset flow, PHC must stay registered
+	 * to keep kernel's PHC index
+	 */
+	if (ena_phc_is_active(adapter) &&
+	    !test_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags)) {
 		ptp_clock_unregister(phc_info->clock);
 		phc_info->clock = NULL;
 	}

From 15115b1a255404795158fa92a1cba87a9acff15d Mon Sep 17 00:00:00 2001
From: David Arinzon <darinzon@amazon.com>
Date: Tue, 17 Jun 2025 14:05:39 +0300
Subject: [PATCH 3/9] net: ena: Add device reload capability through devlink

Adding basic devlink capability support of reloading the driver.
This capability is required to support driver init type
devlink params (DEVLINK_PARAM_CMODE_DRIVERINIT). Such params
require reloading of the driver (destroy/restore sequence).
The reloading is done by the devlink framework using the
hooks provided by the driver.

Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://patch.msgid.link/20250617110545.5659-4-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 .../device_drivers/ethernet/amazon/ena.rst    | 13 +++
 drivers/net/ethernet/amazon/Kconfig           |  1 +
 drivers/net/ethernet/amazon/ena/Makefile      |  2 +-
 drivers/net/ethernet/amazon/ena/ena_devlink.c | 94 +++++++++++++++++++
 drivers/net/ethernet/amazon/ena/ena_devlink.h | 19 ++++
 drivers/net/ethernet/amazon/ena/ena_netdev.c  | 30 +++++-
 drivers/net/ethernet/amazon/ena/ena_netdev.h  |  5 +
 7 files changed, 158 insertions(+), 6 deletions(-)
 create mode 100644 drivers/net/ethernet/amazon/ena/ena_devlink.c
 create mode 100644 drivers/net/ethernet/amazon/ena/ena_devlink.h

diff --git a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
index 98dc62174a40..112a3994bc85 100644
--- a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
+++ b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
@@ -57,6 +57,7 @@ ena_ethtool.c       ethtool callbacks.
 ena_xdp.[ch]        XDP files
 ena_pci_id_tbl.h    Supported device IDs.
 ena_phc.[ch]        PTP hardware clock infrastructure (see `PHC`_ for more info)
+ena_devlink.[ch]    devlink files.
 =================   ======================================================
 
 Management Interface:
@@ -269,6 +270,18 @@ RSS
 - The user can provide a hash key, hash function, and configure the
   indirection table through `ethtool(8)`.
 
+DEVLINK SUPPORT
+===============
+.. _`devlink`: https://www.kernel.org/doc/html/latest/networking/devlink/index.html
+
+`devlink`_ supports reloading the driver and initiating re-negotiation with the ENA device
+
+.. code-block:: shell
+
+  sudo devlink dev reload pci/<domain:bus:slot.function>
+  # for example:
+  sudo devlink dev reload pci/0000:00:06.0
+
 DATA PATH
 =========
 
diff --git a/drivers/net/ethernet/amazon/Kconfig b/drivers/net/ethernet/amazon/Kconfig
index 8d61bc62e295..95dcc3969f0c 100644
--- a/drivers/net/ethernet/amazon/Kconfig
+++ b/drivers/net/ethernet/amazon/Kconfig
@@ -21,6 +21,7 @@ config ENA_ETHERNET
 	depends on PCI_MSI && !CPU_BIG_ENDIAN
 	depends on PTP_1588_CLOCK_OPTIONAL
 	select DIMLIB
+	select NET_DEVLINK
 	help
 	  This driver supports Elastic Network Adapter (ENA)"
 
diff --git a/drivers/net/ethernet/amazon/ena/Makefile b/drivers/net/ethernet/amazon/ena/Makefile
index 8c874177468f..4b6511db873e 100644
--- a/drivers/net/ethernet/amazon/ena/Makefile
+++ b/drivers/net/ethernet/amazon/ena/Makefile
@@ -5,4 +5,4 @@
 
 obj-$(CONFIG_ENA_ETHERNET) += ena.o
 
-ena-y := ena_netdev.o ena_com.o ena_eth_com.o ena_ethtool.o ena_xdp.o ena_phc.o
+ena-y := ena_netdev.o ena_com.o ena_eth_com.o ena_ethtool.o ena_xdp.o ena_phc.o ena_devlink.o
diff --git a/drivers/net/ethernet/amazon/ena/ena_devlink.c b/drivers/net/ethernet/amazon/ena/ena_devlink.c
new file mode 100644
index 000000000000..db56916c7f12
--- /dev/null
+++ b/drivers/net/ethernet/amazon/ena/ena_devlink.c
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) Amazon.com, Inc. or its affiliates.
+ * All rights reserved.
+ */
+
+#include "linux/pci.h"
+#include "ena_devlink.h"
+
+static int ena_devlink_reload_down(struct devlink *devlink,
+				   bool netns_change,
+				   enum devlink_reload_action action,
+				   enum devlink_reload_limit limit,
+				   struct netlink_ext_ack *extack)
+{
+	struct ena_adapter *adapter = ENA_DEVLINK_PRIV(devlink);
+
+	if (netns_change) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Namespace change is not supported");
+		return -EOPNOTSUPP;
+	}
+
+	rtnl_lock();
+	ena_destroy_device(adapter, false);
+	rtnl_unlock();
+
+	return 0;
+}
+
+static int ena_devlink_reload_up(struct devlink *devlink,
+				 enum devlink_reload_action action,
+				 enum devlink_reload_limit limit,
+				 u32 *actions_performed,
+				 struct netlink_ext_ack *extack)
+{
+	struct ena_adapter *adapter = ENA_DEVLINK_PRIV(devlink);
+	int err = 0;
+
+	rtnl_lock();
+	/* Check that no other routine initialized the device (e.g.
+	 * ena_fw_reset_device()). Also we're under devlink_mutex here,
+	 * so devlink isn't freed under our feet.
+	 */
+	if (!test_bit(ENA_FLAG_DEVICE_RUNNING, &adapter->flags))
+		err = ena_restore_device(adapter);
+
+	rtnl_unlock();
+
+	if (!err)
+		*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
+
+	return err;
+}
+
+static const struct devlink_ops ena_devlink_ops = {
+	.reload_actions = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT),
+	.reload_down	= ena_devlink_reload_down,
+	.reload_up	= ena_devlink_reload_up,
+};
+
+struct devlink *ena_devlink_alloc(struct ena_adapter *adapter)
+{
+	struct device *dev = &adapter->pdev->dev;
+	struct devlink *devlink;
+
+	devlink = devlink_alloc(&ena_devlink_ops,
+				sizeof(struct ena_adapter *),
+				dev);
+	if (!devlink) {
+		netdev_err(adapter->netdev,
+			   "Failed to allocate devlink struct\n");
+		return NULL;
+	}
+
+	ENA_DEVLINK_PRIV(devlink) = adapter;
+	adapter->devlink = devlink;
+
+	return devlink;
+}
+
+void ena_devlink_free(struct devlink *devlink)
+{
+	devlink_free(devlink);
+}
+
+void ena_devlink_register(struct devlink *devlink, struct device *dev)
+{
+	devlink_register(devlink);
+}
+
+void ena_devlink_unregister(struct devlink *devlink)
+{
+	devlink_unregister(devlink);
+}
diff --git a/drivers/net/ethernet/amazon/ena/ena_devlink.h b/drivers/net/ethernet/amazon/ena/ena_devlink.h
new file mode 100644
index 000000000000..cb1a5f21a72e
--- /dev/null
+++ b/drivers/net/ethernet/amazon/ena/ena_devlink.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/* Copyright (c) Amazon.com, Inc. or its affiliates.
+ * All rights reserved.
+ */
+#ifndef DEVLINK_H
+#define DEVLINK_H
+
+#include "ena_netdev.h"
+#include <net/devlink.h>
+
+#define ENA_DEVLINK_PRIV(devlink) \
+	(*(struct ena_adapter **)devlink_priv(devlink))
+
+struct devlink *ena_devlink_alloc(struct ena_adapter *adapter);
+void ena_devlink_free(struct devlink *devlink);
+void ena_devlink_register(struct devlink *devlink, struct device *dev);
+void ena_devlink_unregister(struct devlink *devlink);
+
+#endif /* DEVLINK_H */
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index 14a85916464b..ab88895b874e 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -21,6 +21,8 @@
 
 #include "ena_phc.h"
 
+#include "ena_devlink.h"
+
 MODULE_AUTHOR("Amazon.com, Inc. or its affiliates");
 MODULE_DESCRIPTION(DEVICE_NAME);
 MODULE_LICENSE("GPL");
@@ -41,8 +43,6 @@ MODULE_DEVICE_TABLE(pci, ena_pci_tbl);
 
 static int ena_rss_init_default(struct ena_adapter *adapter);
 static void check_for_admin_com_state(struct ena_adapter *adapter);
-static int ena_destroy_device(struct ena_adapter *adapter, bool graceful);
-static int ena_restore_device(struct ena_adapter *adapter);
 
 static void ena_tx_timeout(struct net_device *dev, unsigned int txqueue)
 {
@@ -3240,7 +3240,7 @@ static int ena_enable_msix_and_set_admin_interrupts(struct ena_adapter *adapter)
 	return rc;
 }
 
-static int ena_destroy_device(struct ena_adapter *adapter, bool graceful)
+int ena_destroy_device(struct ena_adapter *adapter, bool graceful)
 {
 	struct net_device *netdev = adapter->netdev;
 	struct ena_com_dev *ena_dev = adapter->ena_dev;
@@ -3291,7 +3291,7 @@ static int ena_destroy_device(struct ena_adapter *adapter, bool graceful)
 	return rc;
 }
 
-static int ena_restore_device(struct ena_adapter *adapter)
+int ena_restore_device(struct ena_adapter *adapter)
 {
 	struct ena_com_dev_get_features_ctx get_feat_ctx;
 	struct ena_com_dev *ena_dev = adapter->ena_dev;
@@ -3877,6 +3877,7 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 	struct ena_adapter *adapter;
 	struct net_device *netdev;
 	static int adapters_found;
+	struct devlink *devlink;
 	u32 max_num_io_queues;
 	bool wd_state;
 	int bars, rc;
@@ -3960,12 +3961,20 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto err_metrics_destroy;
 	}
 
+	/* Need to do this before ena_device_init */
+	devlink = ena_devlink_alloc(adapter);
+	if (!devlink) {
+		netdev_err(netdev, "ena_devlink_alloc failed\n");
+		rc = -ENOMEM;
+		goto err_metrics_destroy;
+	}
+
 	rc = ena_device_init(adapter, pdev, &get_feat_ctx, &wd_state);
 	if (rc) {
 		dev_err(&pdev->dev, "ENA device init failed\n");
 		if (rc == -ETIME)
 			rc = -EPROBE_DEFER;
-		goto err_metrics_destroy;
+		goto ena_devlink_destroy;
 	}
 
 	/* Initial TX and RX interrupt delay. Assumes 1 usec granularity.
@@ -4070,6 +4079,12 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	adapters_found++;
 
+	/* From this point, the devlink device is visible to users.
+	 * Perform the registration last to ensure that all the resources
+	 * are available and that the netdevice is registered.
+	 */
+	ena_devlink_register(devlink, &pdev->dev);
+
 	return 0;
 
 err_rss:
@@ -4086,6 +4101,8 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 err_device_destroy:
 	ena_com_delete_host_info(ena_dev);
 	ena_com_admin_destroy(ena_dev);
+ena_devlink_destroy:
+	ena_devlink_free(devlink);
 err_metrics_destroy:
 	ena_com_delete_customer_metrics_buffer(ena_dev);
 err_free_phc:
@@ -4132,6 +4149,9 @@ static void __ena_shutoff(struct pci_dev *pdev, bool shutdown)
 
 	ena_phc_free(adapter);
 
+	ena_devlink_unregister(adapter->devlink);
+	ena_devlink_free(adapter->devlink);
+
 	if (shutdown) {
 		netif_device_detach(netdev);
 		dev_close(netdev);
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h
index 7867cd7f25bc..a732a19ea97b 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.h
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h
@@ -16,6 +16,7 @@
 #include <linux/skbuff.h>
 #include <net/xdp.h>
 #include <uapi/linux/bpf.h>
+#include <net/devlink.h>
 
 #include "ena_com.h"
 #include "ena_eth_com.h"
@@ -387,6 +388,8 @@ struct ena_adapter {
 	struct bpf_prog *xdp_bpf_prog;
 	u32 xdp_first_ring;
 	u32 xdp_num_queues;
+
+	struct devlink *devlink;
 };
 
 void ena_set_ethtool_ops(struct net_device *netdev);
@@ -416,6 +419,8 @@ static inline void ena_reset_device(struct ena_adapter *adapter,
 	set_bit(ENA_FLAG_TRIGGER_RESET, &adapter->flags);
 }
 
+int ena_destroy_device(struct ena_adapter *adapter, bool graceful);
+int ena_restore_device(struct ena_adapter *adapter);
 int handle_invalid_req_id(struct ena_ring *ring, u16 req_id,
 			  struct ena_tx_buffer *tx_info, bool is_xdp);
 

From 9d67d534e4e0db2cc8b6aeb450edbc997e2594d4 Mon Sep 17 00:00:00 2001
From: David Arinzon <darinzon@amazon.com>
Date: Tue, 17 Jun 2025 14:05:40 +0300
Subject: [PATCH 4/9] net: ena: Add devlink port support

Add the basic functionality to support devlink port
for devlink model completeness purposes.
Current support is for registration/un-registration.

Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://patch.msgid.link/20250617110545.5659-5-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/amazon/ena/ena_devlink.c | 31 +++++++++++++++++--
 drivers/net/ethernet/amazon/ena/ena_netdev.h  |  1 +
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/amazon/ena/ena_devlink.c b/drivers/net/ethernet/amazon/ena/ena_devlink.c
index db56916c7f12..1aa977a6733d 100644
--- a/drivers/net/ethernet/amazon/ena/ena_devlink.c
+++ b/drivers/net/ethernet/amazon/ena/ena_devlink.c
@@ -6,6 +6,23 @@
 #include "linux/pci.h"
 #include "ena_devlink.h"
 
+static void ena_devlink_port_register(struct devlink *devlink)
+{
+	struct ena_adapter *adapter = ENA_DEVLINK_PRIV(devlink);
+	struct devlink_port_attrs attrs = {};
+
+	attrs.flavour = DEVLINK_PORT_FLAVOUR_PHYSICAL;
+	devlink_port_attrs_set(&adapter->devlink_port, &attrs);
+	devl_port_register(devlink, &adapter->devlink_port, 0);
+}
+
+static void ena_devlink_port_unregister(struct devlink *devlink)
+{
+	struct ena_adapter *adapter = ENA_DEVLINK_PRIV(devlink);
+
+	devl_port_unregister(&adapter->devlink_port);
+}
+
 static int ena_devlink_reload_down(struct devlink *devlink,
 				   bool netns_change,
 				   enum devlink_reload_action action,
@@ -20,6 +37,8 @@ static int ena_devlink_reload_down(struct devlink *devlink,
 		return -EOPNOTSUPP;
 	}
 
+	ena_devlink_port_unregister(devlink);
+
 	rtnl_lock();
 	ena_destroy_device(adapter, false);
 	rtnl_unlock();
@@ -46,6 +65,8 @@ static int ena_devlink_reload_up(struct devlink *devlink,
 
 	rtnl_unlock();
 
+	ena_devlink_port_register(devlink);
+
 	if (!err)
 		*actions_performed = BIT(DEVLINK_RELOAD_ACTION_DRIVER_REINIT);
 
@@ -85,10 +106,16 @@ void ena_devlink_free(struct devlink *devlink)
 
 void ena_devlink_register(struct devlink *devlink, struct device *dev)
 {
-	devlink_register(devlink);
+	devl_lock(devlink);
+	ena_devlink_port_register(devlink);
+	devl_register(devlink);
+	devl_unlock(devlink);
 }
 
 void ena_devlink_unregister(struct devlink *devlink)
 {
-	devlink_unregister(devlink);
+	devl_lock(devlink);
+	ena_devlink_port_unregister(devlink);
+	devl_unregister(devlink);
+	devl_unlock(devlink);
 }
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h
index a732a19ea97b..cba67867ccd2 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.h
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h
@@ -390,6 +390,7 @@ struct ena_adapter {
 	u32 xdp_num_queues;
 
 	struct devlink *devlink;
+	struct devlink_port devlink_port;
 };
 
 void ena_set_ethtool_ops(struct net_device *netdev);

From cea465a96a294e7bc2537f27a737cfa7c6234b3d Mon Sep 17 00:00:00 2001
From: David Arinzon <darinzon@amazon.com>
Date: Tue, 17 Jun 2025 14:05:41 +0300
Subject: [PATCH 5/9] devlink: Add new "enable_phc" generic device param

Add a new device generic parameter to enable/disable the
PHC (PTP Hardware Clock) functionality in the device associated
with the devlink instance.

Signed-off-by: David Arinzon <darinzon@amazon.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://patch.msgid.link/20250617110545.5659-6-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 Documentation/networking/devlink/devlink-params.rst | 3 +++
 include/net/devlink.h                               | 4 ++++
 net/devlink/param.c                                 | 5 +++++
 3 files changed, 12 insertions(+)

diff --git a/Documentation/networking/devlink/devlink-params.rst b/Documentation/networking/devlink/devlink-params.rst
index 4e01dc32bc08..3da8f4ef2417 100644
--- a/Documentation/networking/devlink/devlink-params.rst
+++ b/Documentation/networking/devlink/devlink-params.rst
@@ -137,3 +137,6 @@ own name.
    * - ``event_eq_size``
      - u32
      - Control the size of asynchronous control events EQ.
+   * - ``enable_phc``
+     - Boolean
+     - Enable PHC (PTP Hardware Clock) functionality in the device.
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 0091f23a40f7..63517646a497 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -520,6 +520,7 @@ enum devlink_param_generic_id {
 	DEVLINK_PARAM_GENERIC_ID_ENABLE_IWARP,
 	DEVLINK_PARAM_GENERIC_ID_IO_EQ_SIZE,
 	DEVLINK_PARAM_GENERIC_ID_EVENT_EQ_SIZE,
+	DEVLINK_PARAM_GENERIC_ID_ENABLE_PHC,
 
 	/* add new param generic ids above here*/
 	__DEVLINK_PARAM_GENERIC_ID_MAX,
@@ -578,6 +579,9 @@ enum devlink_param_generic_id {
 #define DEVLINK_PARAM_GENERIC_EVENT_EQ_SIZE_NAME "event_eq_size"
 #define DEVLINK_PARAM_GENERIC_EVENT_EQ_SIZE_TYPE DEVLINK_PARAM_TYPE_U32
 
+#define DEVLINK_PARAM_GENERIC_ENABLE_PHC_NAME "enable_phc"
+#define DEVLINK_PARAM_GENERIC_ENABLE_PHC_TYPE DEVLINK_PARAM_TYPE_BOOL
+
 #define DEVLINK_PARAM_GENERIC(_id, _cmodes, _get, _set, _validate)	\
 {									\
 	.id = DEVLINK_PARAM_GENERIC_ID_##_id,				\
diff --git a/net/devlink/param.c b/net/devlink/param.c
index b29abf8d3ed4..396b8a7f6013 100644
--- a/net/devlink/param.c
+++ b/net/devlink/param.c
@@ -92,6 +92,11 @@ static const struct devlink_param devlink_param_generic[] = {
 		.name = DEVLINK_PARAM_GENERIC_EVENT_EQ_SIZE_NAME,
 		.type = DEVLINK_PARAM_GENERIC_EVENT_EQ_SIZE_TYPE,
 	},
+	{
+		.id = DEVLINK_PARAM_GENERIC_ID_ENABLE_PHC,
+		.name = DEVLINK_PARAM_GENERIC_ENABLE_PHC_NAME,
+		.type = DEVLINK_PARAM_GENERIC_ENABLE_PHC_TYPE,
+	},
 };
 
 static int devlink_param_generic_verify(const struct devlink_param *param)

From 816b52624cf6a03ea541956b448025d844a8287d Mon Sep 17 00:00:00 2001
From: David Arinzon <darinzon@amazon.com>
Date: Tue, 17 Jun 2025 14:05:42 +0300
Subject: [PATCH 6/9] net: ena: Control PHC enable through devlink

Add the capability to set parameters through the devlink framework.

The parameter used for controlling PHC (enable/disable) details
are as follows:
- Name: enable_phc
- Type: Boolean (true - enable/false - disable)
- Mode: DEVLINK_PARAM_CMODE_DRIVERINIT
- Effect: Changes take place during driver initialization,
          any changes require a devlink reload to take effect.

Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://patch.msgid.link/20250617110545.5659-7-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/amazon/ena/ena_devlink.c | 89 +++++++++++++++++++
 drivers/net/ethernet/amazon/ena/ena_devlink.h |  2 +
 drivers/net/ethernet/amazon/ena/ena_netdev.c  |  2 +
 drivers/net/ethernet/amazon/ena/ena_phc.c     |  2 +
 4 files changed, 95 insertions(+)

diff --git a/drivers/net/ethernet/amazon/ena/ena_devlink.c b/drivers/net/ethernet/amazon/ena/ena_devlink.c
index 1aa977a6733d..ac81c24016dd 100644
--- a/drivers/net/ethernet/amazon/ena/ena_devlink.c
+++ b/drivers/net/ethernet/amazon/ena/ena_devlink.c
@@ -5,6 +5,59 @@
 
 #include "linux/pci.h"
 #include "ena_devlink.h"
+#include "ena_phc.h"
+
+static int ena_devlink_enable_phc_validate(struct devlink *devlink, u32 id,
+					   union devlink_param_value val,
+					   struct netlink_ext_ack *extack)
+{
+	struct ena_adapter *adapter = ENA_DEVLINK_PRIV(devlink);
+
+	if (!val.vbool)
+		return 0;
+
+	if (!ena_com_phc_supported(adapter->ena_dev)) {
+		NL_SET_ERR_MSG_MOD(extack, "Device doesn't support PHC");
+		return -EOPNOTSUPP;
+	}
+
+	return 0;
+}
+
+static const struct devlink_param ena_devlink_params[] = {
+	DEVLINK_PARAM_GENERIC(ENABLE_PHC,
+			      BIT(DEVLINK_PARAM_CMODE_DRIVERINIT),
+			      NULL,
+			      NULL,
+			      ena_devlink_enable_phc_validate),
+};
+
+void ena_devlink_params_get(struct devlink *devlink)
+{
+	struct ena_adapter *adapter = ENA_DEVLINK_PRIV(devlink);
+	union devlink_param_value val;
+	int err;
+
+	err = devl_param_driverinit_value_get(devlink,
+					      DEVLINK_PARAM_GENERIC_ID_ENABLE_PHC,
+					      &val);
+	if (err) {
+		netdev_err(adapter->netdev, "Failed to query PHC param\n");
+		return;
+	}
+
+	ena_phc_enable(adapter, val.vbool);
+}
+
+void ena_devlink_disable_phc_param(struct devlink *devlink)
+{
+	union devlink_param_value value;
+
+	value.vbool = false;
+	devl_param_driverinit_value_set(devlink,
+					DEVLINK_PARAM_GENERIC_ID_ENABLE_PHC,
+					value);
+}
 
 static void ena_devlink_port_register(struct devlink *devlink)
 {
@@ -79,6 +132,27 @@ static const struct devlink_ops ena_devlink_ops = {
 	.reload_up	= ena_devlink_reload_up,
 };
 
+static int ena_devlink_configure_params(struct devlink *devlink)
+{
+	struct ena_adapter *adapter = ENA_DEVLINK_PRIV(devlink);
+	union devlink_param_value value;
+	int rc;
+
+	rc = devlink_params_register(devlink, ena_devlink_params,
+				     ARRAY_SIZE(ena_devlink_params));
+	if (rc) {
+		netdev_err(adapter->netdev, "Failed to register devlink params\n");
+		return rc;
+	}
+
+	value.vbool = ena_phc_is_enabled(adapter);
+	devl_param_driverinit_value_set(devlink,
+					DEVLINK_PARAM_GENERIC_ID_ENABLE_PHC,
+					value);
+
+	return 0;
+}
+
 struct devlink *ena_devlink_alloc(struct ena_adapter *adapter)
 {
 	struct device *dev = &adapter->pdev->dev;
@@ -96,11 +170,26 @@ struct devlink *ena_devlink_alloc(struct ena_adapter *adapter)
 	ENA_DEVLINK_PRIV(devlink) = adapter;
 	adapter->devlink = devlink;
 
+	if (ena_devlink_configure_params(devlink))
+		goto free_devlink;
+
 	return devlink;
+
+free_devlink:
+	devlink_free(devlink);
+	return NULL;
+}
+
+static void ena_devlink_configure_params_clean(struct devlink *devlink)
+{
+	devlink_params_unregister(devlink, ena_devlink_params,
+				  ARRAY_SIZE(ena_devlink_params));
 }
 
 void ena_devlink_free(struct devlink *devlink)
 {
+	ena_devlink_configure_params_clean(devlink);
+
 	devlink_free(devlink);
 }
 
diff --git a/drivers/net/ethernet/amazon/ena/ena_devlink.h b/drivers/net/ethernet/amazon/ena/ena_devlink.h
index cb1a5f21a72e..7a19ce4830d9 100644
--- a/drivers/net/ethernet/amazon/ena/ena_devlink.h
+++ b/drivers/net/ethernet/amazon/ena/ena_devlink.h
@@ -15,5 +15,7 @@ struct devlink *ena_devlink_alloc(struct ena_adapter *adapter);
 void ena_devlink_free(struct devlink *devlink);
 void ena_devlink_register(struct devlink *devlink, struct device *dev);
 void ena_devlink_unregister(struct devlink *devlink);
+void ena_devlink_params_get(struct devlink *devlink);
+void ena_devlink_disable_phc_param(struct devlink *devlink);
 
 #endif /* DEVLINK_H */
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index ab88895b874e..cf1b817bf1e0 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -3138,6 +3138,8 @@ static int ena_device_init(struct ena_adapter *adapter, struct pci_dev *pdev,
 		goto err_mmio_read_less;
 	}
 
+	ena_devlink_params_get(adapter->devlink);
+
 	/* ENA admin level init */
 	rc = ena_com_admin_init(ena_dev, &aenq_handlers);
 	if (rc) {
diff --git a/drivers/net/ethernet/amazon/ena/ena_phc.c b/drivers/net/ethernet/amazon/ena/ena_phc.c
index 5ce9a32d210a..7867e893fd15 100644
--- a/drivers/net/ethernet/amazon/ena/ena_phc.c
+++ b/drivers/net/ethernet/amazon/ena/ena_phc.c
@@ -6,6 +6,7 @@
 #include <linux/pci.h>
 #include "ena_netdev.h"
 #include "ena_phc.h"
+#include "ena_devlink.h"
 
 static int ena_phc_adjtime(struct ptp_clock_info *clock_info, s64 delta)
 {
@@ -213,6 +214,7 @@ int ena_phc_init(struct ena_adapter *adapter)
 	ena_com_phc_destroy(ena_dev);
 err_ena_com_phc_init:
 	ena_phc_enable(adapter, false);
+	ena_devlink_disable_phc_param(adapter->devlink);
 	return rc;
 }
 

From 60e28350b1ca127fe22dd99d5ff2a1922450e912 Mon Sep 17 00:00:00 2001
From: David Arinzon <darinzon@amazon.com>
Date: Tue, 17 Jun 2025 14:05:43 +0300
Subject: [PATCH 7/9] net: ena: Add debugfs support to the ENA driver

Adding the base directory of debugfs to the driver.
In order for the folder to be unique per driver instantiation,
the chosen name is the device name.

This commit contains the initialization and the
base folder.

The creation of the base folder may fail, but is considered
non-fatal.

Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://patch.msgid.link/20250617110545.5659-8-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 .../device_drivers/ethernet/amazon/ena.rst    |  1 +
 drivers/net/ethernet/amazon/ena/Makefile      |  2 +-
 drivers/net/ethernet/amazon/ena/ena_debugfs.c | 27 +++++++++++++++++++
 drivers/net/ethernet/amazon/ena/ena_debugfs.h | 27 +++++++++++++++++++
 drivers/net/ethernet/amazon/ena/ena_netdev.c  |  6 +++++
 drivers/net/ethernet/amazon/ena/ena_netdev.h  |  4 +++
 6 files changed, 66 insertions(+), 1 deletion(-)
 create mode 100644 drivers/net/ethernet/amazon/ena/ena_debugfs.c
 create mode 100644 drivers/net/ethernet/amazon/ena/ena_debugfs.h

diff --git a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
index 112a3994bc85..7b7b8891cec9 100644
--- a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
+++ b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
@@ -58,6 +58,7 @@ ena_xdp.[ch]        XDP files
 ena_pci_id_tbl.h    Supported device IDs.
 ena_phc.[ch]        PTP hardware clock infrastructure (see `PHC`_ for more info)
 ena_devlink.[ch]    devlink files.
+ena_debugfs.[ch]    debugfs files.
 =================   ======================================================
 
 Management Interface:
diff --git a/drivers/net/ethernet/amazon/ena/Makefile b/drivers/net/ethernet/amazon/ena/Makefile
index 4b6511db873e..6d8036bc1823 100644
--- a/drivers/net/ethernet/amazon/ena/Makefile
+++ b/drivers/net/ethernet/amazon/ena/Makefile
@@ -5,4 +5,4 @@
 
 obj-$(CONFIG_ENA_ETHERNET) += ena.o
 
-ena-y := ena_netdev.o ena_com.o ena_eth_com.o ena_ethtool.o ena_xdp.o ena_phc.o ena_devlink.o
+ena-y := ena_netdev.o ena_com.o ena_eth_com.o ena_ethtool.o ena_xdp.o ena_phc.o ena_devlink.o ena_debugfs.o
diff --git a/drivers/net/ethernet/amazon/ena/ena_debugfs.c b/drivers/net/ethernet/amazon/ena/ena_debugfs.c
new file mode 100644
index 000000000000..d9327cd870e0
--- /dev/null
+++ b/drivers/net/ethernet/amazon/ena/ena_debugfs.c
@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
+/* Copyright (c) Amazon.com, Inc. or its affiliates.
+ * All rights reserved.
+ */
+
+#ifdef CONFIG_DEBUG_FS
+
+#include <linux/seq_file.h>
+#include <linux/pci.h>
+#include "ena_debugfs.h"
+
+void ena_debugfs_init(struct net_device *dev)
+{
+	struct ena_adapter *adapter = netdev_priv(dev);
+
+	adapter->debugfs_base =
+		debugfs_create_dir(dev_name(&adapter->pdev->dev), NULL);
+}
+
+void ena_debugfs_terminate(struct net_device *dev)
+{
+	struct ena_adapter *adapter = netdev_priv(dev);
+
+	debugfs_remove_recursive(adapter->debugfs_base);
+}
+
+#endif /* CONFIG_DEBUG_FS */
diff --git a/drivers/net/ethernet/amazon/ena/ena_debugfs.h b/drivers/net/ethernet/amazon/ena/ena_debugfs.h
new file mode 100644
index 000000000000..dc61dd998867
--- /dev/null
+++ b/drivers/net/ethernet/amazon/ena/ena_debugfs.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB */
+/* Copyright (c) Amazon.com, Inc. or its affiliates.
+ * All rights reserved.
+ */
+
+#ifndef __ENA_DEBUGFS_H__
+#define __ENA_DEBUGFS_H__
+
+#include <linux/debugfs.h>
+#include <linux/netdevice.h>
+#include "ena_netdev.h"
+
+#ifdef CONFIG_DEBUG_FS
+
+void ena_debugfs_init(struct net_device *dev);
+
+void ena_debugfs_terminate(struct net_device *dev);
+
+#else /* CONFIG_DEBUG_FS */
+
+static inline void ena_debugfs_init(struct net_device *dev) {}
+
+static inline void ena_debugfs_terminate(struct net_device *dev) {}
+
+#endif /* CONFIG_DEBUG_FS */
+
+#endif /* __ENA_DEBUGFS_H__ */
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.c b/drivers/net/ethernet/amazon/ena/ena_netdev.c
index cf1b817bf1e0..92d149d4f091 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.c
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.c
@@ -23,6 +23,8 @@
 
 #include "ena_devlink.h"
 
+#include "ena_debugfs.h"
+
 MODULE_AUTHOR("Amazon.com, Inc. or its affiliates");
 MODULE_DESCRIPTION(DEVICE_NAME);
 MODULE_LICENSE("GPL");
@@ -4060,6 +4062,8 @@ static int ena_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 		goto err_rss;
 	}
 
+	ena_debugfs_init(netdev);
+
 	INIT_WORK(&adapter->reset_task, ena_fw_reset_device);
 
 	adapter->last_keep_alive_jiffies = jiffies;
@@ -4139,6 +4143,8 @@ static void __ena_shutoff(struct pci_dev *pdev, bool shutdown)
 	ena_dev = adapter->ena_dev;
 	netdev = adapter->netdev;
 
+	ena_debugfs_terminate(netdev);
+
 	/* Make sure timer and reset routine won't be called after
 	 * freeing device resources.
 	 */
diff --git a/drivers/net/ethernet/amazon/ena/ena_netdev.h b/drivers/net/ethernet/amazon/ena/ena_netdev.h
index cba67867ccd2..006f9a3acea6 100644
--- a/drivers/net/ethernet/amazon/ena/ena_netdev.h
+++ b/drivers/net/ethernet/amazon/ena/ena_netdev.h
@@ -391,6 +391,10 @@ struct ena_adapter {
 
 	struct devlink *devlink;
 	struct devlink_port devlink_port;
+#ifdef CONFIG_DEBUG_FS
+
+	struct dentry *debugfs_base;
+#endif /* CONFIG_DEBUG_FS */
 };
 
 void ena_set_ethtool_ops(struct net_device *netdev);

From e14521e97b8341852d70ddb23e7cd94d04302d09 Mon Sep 17 00:00:00 2001
From: David Arinzon <darinzon@amazon.com>
Date: Tue, 17 Jun 2025 14:05:44 +0300
Subject: [PATCH 8/9] net: ena: View PHC stats using debugfs

Add an entry named `phc_stats` to view the PHC statistics.
If PHC is enabled, the stats are printed, as below:

phc_cnt: 0
phc_exp: 0
phc_skp: 0
phc_err_dv: 0
phc_err_ts: 0

If PHC is disabled, no statistics will be displayed.

Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://patch.msgid.link/20250617110545.5659-9-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 drivers/net/ethernet/amazon/ena/ena_debugfs.c | 35 +++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/net/ethernet/amazon/ena/ena_debugfs.c b/drivers/net/ethernet/amazon/ena/ena_debugfs.c
index d9327cd870e0..46ed80986724 100644
--- a/drivers/net/ethernet/amazon/ena/ena_debugfs.c
+++ b/drivers/net/ethernet/amazon/ena/ena_debugfs.c
@@ -8,6 +8,35 @@
 #include <linux/seq_file.h>
 #include <linux/pci.h>
 #include "ena_debugfs.h"
+#include "ena_phc.h"
+
+static int phc_stats_show(struct seq_file *file, void *priv)
+{
+	struct ena_adapter *adapter = file->private;
+
+	if (!ena_phc_is_active(adapter))
+		return 0;
+
+	seq_printf(file,
+		   "phc_cnt: %llu\n",
+		   adapter->ena_dev->phc.stats.phc_cnt);
+	seq_printf(file,
+		   "phc_exp: %llu\n",
+		   adapter->ena_dev->phc.stats.phc_exp);
+	seq_printf(file,
+		   "phc_skp: %llu\n",
+		   adapter->ena_dev->phc.stats.phc_skp);
+	seq_printf(file,
+		   "phc_err_dv: %llu\n",
+		   adapter->ena_dev->phc.stats.phc_err_dv);
+	seq_printf(file,
+		   "phc_err_ts: %llu\n",
+		   adapter->ena_dev->phc.stats.phc_err_ts);
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(phc_stats);
 
 void ena_debugfs_init(struct net_device *dev)
 {
@@ -15,6 +44,12 @@ void ena_debugfs_init(struct net_device *dev)
 
 	adapter->debugfs_base =
 		debugfs_create_dir(dev_name(&adapter->pdev->dev), NULL);
+
+	debugfs_create_file("phc_stats",
+			    0400,
+			    adapter->debugfs_base,
+			    adapter,
+			    &phc_stats_fops);
 }
 
 void ena_debugfs_terminate(struct net_device *dev)

From c9223021433d9b2d4ca32cf9e582e6908f08c3cb Mon Sep 17 00:00:00 2001
From: David Arinzon <darinzon@amazon.com>
Date: Tue, 17 Jun 2025 14:05:45 +0300
Subject: [PATCH 9/9] net: ena: Add PHC documentation

Provide the relevant information and guidelines
about the feature support in the ENA driver.

Signed-off-by: Amit Bernstein <amitbern@amazon.com>
Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://patch.msgid.link/20250617110545.5659-10-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 .../device_drivers/ethernet/amazon/ena.rst    | 93 +++++++++++++++++++
 1 file changed, 93 insertions(+)

diff --git a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
index 7b7b8891cec9..14784a0a6a8a 100644
--- a/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
+++ b/Documentation/networking/device_drivers/ethernet/amazon/ena.rst
@@ -224,6 +224,99 @@ descriptor it was received on would be recycled. When a packet smaller
 than RX copybreak bytes is received, it is copied into a new memory
 buffer and the RX descriptor is returned to HW.
 
+.. _`PHC`:
+
+PTP Hardware Clock (PHC)
+========================
+.. _`ptp-userspace-api`: https://docs.kernel.org/driver-api/ptp.html#ptp-hardware-clock-user-space-api
+.. _`testptp`: https://elixir.bootlin.com/linux/latest/source/tools/testing/selftests/ptp/testptp.c
+
+ENA Linux driver supports PTP hardware clock providing timestamp reference to achieve nanosecond resolution.
+
+**PHC support**
+
+PHC depends on the PTP module, which needs to be either loaded as a module or compiled into the kernel.
+
+Verify if the PTP module is present:
+
+.. code-block:: shell
+
+  grep -w '^CONFIG_PTP_1588_CLOCK=[ym]' /boot/config-`uname -r`
+
+- If no output is provided, the ENA driver cannot be loaded with PHC support.
+
+**PHC activation**
+
+The feature is turned off by default, in order to turn the feature on, the ENA driver
+can be loaded in the following way:
+
+- devlink:
+
+.. code-block:: shell
+
+  sudo devlink dev param set pci/<domain:bus:slot.function> name enable_phc value true cmode driverinit
+  sudo devlink dev reload pci/<domain:bus:slot.function>
+  # for example:
+  sudo devlink dev param set pci/0000:00:06.0 name enable_phc value true cmode driverinit
+  sudo devlink dev reload pci/0000:00:06.0
+
+All available PTP clock sources can be tracked here:
+
+.. code-block:: shell
+
+  ls /sys/class/ptp
+
+PHC support and capabilities can be verified using ethtool:
+
+.. code-block:: shell
+
+  ethtool -T <interface>
+
+**PHC timestamp**
+
+To retrieve PHC timestamp, use `ptp-userspace-api`_, usage example using `testptp`_:
+
+.. code-block:: shell
+
+  testptp -d /dev/ptp$(ethtool -T <interface> | awk '/PTP Hardware Clock:/ {print $NF}') -k 1
+
+PHC get time requests should be within reasonable bounds,
+avoid excessive utilization to ensure optimal performance and efficiency.
+The ENA device restricts the frequency of PHC get time requests to a maximum
+of 125 requests per second. If this limit is surpassed, the get time request
+will fail, leading to an increment in the phc_err_ts statistic.
+
+**PHC statistics**
+
+PHC can be monitored using debugfs (if mounted):
+
+.. code-block:: shell
+
+  sudo cat /sys/kernel/debug/<domain:bus:slot.function>/phc_stats
+
+  # for example:
+  sudo cat /sys/kernel/debug/0000:00:06.0/phc_stats
+
+PHC errors must remain below 1% of all PHC requests to maintain the desired level of accuracy and reliability
+
+=================   ======================================================
+**phc_cnt**         | Number of successful retrieved timestamps (below expire timeout).
+**phc_exp**         | Number of expired retrieved timestamps (above expire timeout).
+**phc_skp**         | Number of skipped get time attempts (during block period).
+**phc_err_dv**      | Number of failed get time attempts due to device errors (entering into block state).
+**phc_err_ts**      | Number of failed get time attempts due to timestamp errors (entering into block state),
+                    | This occurs if driver exceeded the request limit or device received an invalid timestamp.
+=================   ======================================================
+
+PHC timeouts:
+
+=================   ======================================================
+**expire**          | Max time for a valid timestamp retrieval, passing this threshold will fail
+                    | the get time request and block new requests until block timeout.
+**block**           | Blocking period starts once get time request expires or fails,
+                    | all get time requests during block period will be skipped.
+=================   ======================================================
+
 Statistics
 ==========