ptp: Support for multiple filtered timestamp event queue readers

index 362bf756e6b7..0ba3e7064df2 100644
@@ -101,14 +101,16 @@ int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
 	return 0;
 }
 
-int ptp_open(struct posix_clock *pc, fmode_t fmode)
+int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 {
 	return 0;
 }
 
-long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
+long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
+	       unsigned long arg)
 {
-	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 	struct ptp_sys_offset_extended *extoff = NULL;
 	struct ptp_sys_offset_precise precise_offset;
 	struct system_device_crosststamp xtstamp;

@@ -432,9 +434,11 @@ long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 	return err;
 }
 
-__poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
+__poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp,
+		  poll_table *wait)
 {
-	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 
 	poll_wait(fp, &ptp->tsev_wq, wait);
 

@@ -443,10 +447,11 @@ __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
 
 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
 
-ssize_t ptp_read(struct posix_clock *pc,
-		 uint rdflags, char __user *buf, size_t cnt)
+ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
+		 char __user *buf, size_t cnt)
 {
-	struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
 	struct timestamp_event_queue *queue = &ptp->tsevq;
 	struct ptp_extts_event *event;
 	unsigned long flags;

index 75f58fc468a7..a3110c85f694 100644
@@ -117,16 +117,18 @@ extern struct class *ptp_class;
 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
 		    enum ptp_pin_function func, unsigned int chan);
 
-long ptp_ioctl(struct posix_clock *pc,
-	       unsigned int cmd, unsigned long arg);
+long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
+	       unsigned long arg);
 
-int ptp_open(struct posix_clock *pc, fmode_t fmode);
+int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode);
 
-ssize_t ptp_read(struct posix_clock *pc,
-		 uint flags, char __user *buf, size_t cnt);
+int ptp_release(struct posix_clock_context *pccontext);
 
-__poll_t ptp_poll(struct posix_clock *pc,
-	      struct file *fp, poll_table *wait);
+ssize_t ptp_read(struct posix_clock_context *pccontext, uint flags, char __user *buf,
+		 size_t cnt);
+
+__poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp,
+		  poll_table *wait);
 
 /*
  * see ptp_sysfs.c

index 468328b1e1dd..d7c6f126575f 100644
@@ -14,6 +14,7 @@
 #include <linux/rwsem.h>
 
 struct posix_clock;
+struct posix_clock_context;
 
 /**
  * struct posix_clock_operations - functional interface to the clock

@@ -50,18 +51,18 @@ struct posix_clock_operations {
 	/*
 	 * Optional character device methods:
 	 */
-	long    (*ioctl)   (struct posix_clock *pc,
-			    unsigned int cmd, unsigned long arg);
+	long (*ioctl)(struct posix_clock_context *pccontext, unsigned int cmd,
+		      unsigned long arg);
 
-	int     (*open)    (struct posix_clock *pc, fmode_t f_mode);
+	int (*open)(struct posix_clock_context *pccontext, fmode_t f_mode);
 
-	__poll_t (*poll)   (struct posix_clock *pc,
-			    struct file *file, poll_table *wait);
+	__poll_t (*poll)(struct posix_clock_context *pccontext, struct file *file,
+			 poll_table *wait);
 
-	int     (*release) (struct posix_clock *pc);
+	int (*release)(struct posix_clock_context *pccontext);
 
-	ssize_t (*read)    (struct posix_clock *pc,
-			    uint flags, char __user *buf, size_t cnt);
+	ssize_t (*read)(struct posix_clock_context *pccontext, uint flags,
+			char __user *buf, size_t cnt);
 };
 
 /**

@@ -90,6 +91,11 @@ struct posix_clock {
 	bool zombie;
 };
 
+struct posix_clock_context {
+	struct posix_clock *clk;
+	void *private_clkdata;
+};
+
 /**
  * posix_clock_register() - register a new clock
  * @clk:   Pointer to the clock. Caller must provide 'ops' field

index 77c0c2370b6d..9de66bbbb3d1 100644
@@ -19,7 +19,8 @@
  */
 static struct posix_clock *get_posix_clock(struct file *fp)
 {
-	struct posix_clock *clk = fp->private_data;
+	struct posix_clock_context *pccontext = fp->private_data;
+	struct posix_clock *clk = pccontext->clk;
 
 	down_read(&clk->rwsem);
 

@@ -39,6 +40,7 @@ static void put_posix_clock(struct posix_clock *clk)
 static ssize_t posix_clock_read(struct file *fp, char __user *buf,
 				size_t count, loff_t *ppos)
 {
+	struct posix_clock_context *pccontext = fp->private_data;
 	struct posix_clock *clk = get_posix_clock(fp);
 	int err = -EINVAL;
 

@@ -46,7 +48,7 @@ static ssize_t posix_clock_read(struct file *fp, char __user *buf,
 		return -ENODEV;
 
 	if (clk->ops.read)
-		err = clk->ops.read(clk, fp->f_flags, buf, count);
+		err = clk->ops.read(pccontext, fp->f_flags, buf, count);
 
 	put_posix_clock(clk);
 

@@ -55,6 +57,7 @@ static ssize_t posix_clock_read(struct file *fp, char __user *buf,
 
 static __poll_t posix_clock_poll(struct file *fp, poll_table *wait)
 {
+	struct posix_clock_context *pccontext = fp->private_data;
 	struct posix_clock *clk = get_posix_clock(fp);
 	__poll_t result = 0;
 

@@ -62,7 +65,7 @@ static __poll_t posix_clock_poll(struct file *fp, poll_table *wait)
 		return EPOLLERR;
 
 	if (clk->ops.poll)
-		result = clk->ops.poll(clk, fp, wait);
+		result = clk->ops.poll(pccontext, fp, wait);
 
 	put_posix_clock(clk);
 

@@ -72,6 +75,7 @@ static __poll_t posix_clock_poll(struct file *fp, poll_table *wait)
 static long posix_clock_ioctl(struct file *fp,
 			      unsigned int cmd, unsigned long arg)
 {
+	struct posix_clock_context *pccontext = fp->private_data;
 	struct posix_clock *clk = get_posix_clock(fp);
 	int err = -ENOTTY;
 

@@ -79,7 +83,7 @@ static long posix_clock_ioctl(struct file *fp,
 		return -ENODEV;
 
 	if (clk->ops.ioctl)
-		err = clk->ops.ioctl(clk, cmd, arg);
+		err = clk->ops.ioctl(pccontext, cmd, arg);
 
 	put_posix_clock(clk);
 

@@ -90,6 +94,7 @@ static long posix_clock_ioctl(struct file *fp,
 static long posix_clock_compat_ioctl(struct file *fp,
 				     unsigned int cmd, unsigned long arg)
 {
+	struct posix_clock_context *pccontext = fp->private_data;
 	struct posix_clock *clk = get_posix_clock(fp);
 	int err = -ENOTTY;
 

@@ -97,7 +102,7 @@ static long posix_clock_compat_ioctl(struct file *fp,
 		return -ENODEV;
 
 	if (clk->ops.ioctl)
-		err = clk->ops.ioctl(clk, cmd, arg);
+		err = clk->ops.ioctl(pccontext, cmd, arg);
 
 	put_posix_clock(clk);
 

@@ -110,6 +115,7 @@ static int posix_clock_open(struct inode *inode, struct file *fp)
 	int err;
 	struct posix_clock *clk =
 		container_of(inode->i_cdev, struct posix_clock, cdev);
+	struct posix_clock_context *pccontext;
 
 	down_read(&clk->rwsem);
 

@@ -117,14 +123,20 @@ static int posix_clock_open(struct inode *inode, struct file *fp)
 		err = -ENODEV;
 		goto out;
 	}
+	pccontext = kzalloc(sizeof(*pccontext), GFP_KERNEL);
+	if (!pccontext) {
+		err = -ENOMEM;
+		goto out;
+	}
+	pccontext->clk = clk;
+	fp->private_data = pccontext;
 	if (clk->ops.open)
-		err = clk->ops.open(clk, fp->f_mode);
+		err = clk->ops.open(pccontext, fp->f_mode);
 	else
 		err = 0;
 
 	if (!err) {
 		get_device(clk->dev);
-		fp->private_data = clk;
 	}
 out:
 	up_read(&clk->rwsem);

@@ -133,14 +145,20 @@ static int posix_clock_open(struct inode *inode, struct file *fp)
 
 static int posix_clock_release(struct inode *inode, struct file *fp)
 {
-	struct posix_clock *clk = fp->private_data;
+	struct posix_clock_context *pccontext = fp->private_data;
+	struct posix_clock *clk;
 	int err = 0;
 
+	if (!pccontext)
+		return -ENODEV;
+	clk = pccontext->clk;
+
 	if (clk->ops.release)
-		err = clk->ops.release(clk);
+		err = clk->ops.release(pccontext);
 
 	put_device(clk->dev);
 
+	kfree(pccontext);
 	fp->private_data = NULL;
 
 	return err;

index 0ba3e7064df2..aa1990d2ab46 100644
@@ -439,10 +439,14 @@ __poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp,
 {
 	struct ptp_clock *ptp =
 		container_of(pccontext->clk, struct ptp_clock, clock);
+	struct timestamp_event_queue *queue;
 
 	poll_wait(fp, &ptp->tsev_wq, wait);
 
-	return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
+	/* Extract only the first element in the queue list */
+	queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue, qlist);
+
+	return queue_cnt(queue) ? EPOLLIN : 0;
 }
 
 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))

@@ -452,12 +456,16 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 {
 	struct ptp_clock *ptp =
 		container_of(pccontext->clk, struct ptp_clock, clock);
-	struct timestamp_event_queue *queue = &ptp->tsevq;
+	struct timestamp_event_queue *queue;
 	struct ptp_extts_event *event;
 	unsigned long flags;
 	size_t qcnt, i;
 	int result;
 
+	/* Extract only the first element in the queue list */
+	queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
+				 qlist);
+
 	if (cnt % sizeof(struct ptp_extts_event) != 0)
 		return -EINVAL;
 

index 80f74e38c2da..157ef25bc1b1 100644
@@ -169,12 +169,21 @@ static struct posix_clock_operations ptp_clock_ops = {
 static void ptp_clock_release(struct device *dev)
 {
 	struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev);
+	struct timestamp_event_queue *tsevq;
+	unsigned long flags;
 
 	ptp_cleanup_pin_groups(ptp);
 	kfree(ptp->vclock_index);
 	mutex_destroy(&ptp->tsevq_mux);
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
+	/* Delete first entry */
+	tsevq = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
+				 qlist);
+	spin_lock_irqsave(&tsevq->lock, flags);
+	list_del(&tsevq->qlist);
+	spin_unlock_irqrestore(&tsevq->lock, flags);
+	kfree(tsevq);
 	ida_free(&ptp_clocks_map, ptp->index);
 	kfree(ptp);
 }

@@ -206,6 +215,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 				     struct device *parent)
 {
 	struct ptp_clock *ptp;
+	struct timestamp_event_queue *queue = NULL;
 	int err = 0, index, major = MAJOR(ptp_devt);
 	size_t size;
 

@@ -228,7 +238,12 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	ptp->info = info;
 	ptp->devid = MKDEV(major, index);
 	ptp->index = index;
-	spin_lock_init(&ptp->tsevq.lock);
+	INIT_LIST_HEAD(&ptp->tsevqs);
+	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
+	if (!queue)
+		goto no_memory_queue;
+	spin_lock_init(&queue->lock);
+	list_add_tail(&queue->qlist, &ptp->tsevqs);
 	mutex_init(&ptp->tsevq_mux);
 	mutex_init(&ptp->pincfg_mux);
 	mutex_init(&ptp->n_vclocks_mux);

@@ -333,6 +348,9 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	mutex_destroy(&ptp->tsevq_mux);
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
+	list_del(&queue->qlist);
+	kfree(queue);
+no_memory_queue:
 	ida_free(&ptp_clocks_map, index);
 no_slot:
 	kfree(ptp);

@@ -375,6 +393,7 @@ EXPORT_SYMBOL(ptp_clock_unregister);
 
 void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 {
+	struct timestamp_event_queue *tsevq;
 	struct pps_event_time evt;
 
 	switch (event->type) {

@@ -383,7 +402,10 @@ void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 		break;
 
 	case PTP_CLOCK_EXTTS:
-		enqueue_external_timestamp(&ptp->tsevq, event);
+		/* Enqueue timestamp on all queues */
+		list_for_each_entry(tsevq, &ptp->tsevqs, qlist) {
+			enqueue_external_timestamp(tsevq, event);
+		}
 		wake_up_interruptible(&ptp->tsev_wq);
 		break;
 

index a3110c85f694..cc8186a92eec 100644
@@ -15,6 +15,7 @@
 #include <linux/ptp_clock.h>
 #include <linux/ptp_clock_kernel.h>
 #include <linux/time.h>
+#include <linux/list.h>
 
 #define PTP_MAX_TIMESTAMPS 128
 #define PTP_BUF_TIMESTAMPS 30

@@ -25,6 +26,7 @@ struct timestamp_event_queue {
 	int head;
 	int tail;
 	spinlock_t lock;
+	struct list_head qlist;
 };
 
 struct ptp_clock {

@@ -35,7 +37,7 @@ struct ptp_clock {
 	int index; /* index into clocks.map */
 	struct pps_device *pps_source;
 	long dialed_frequency; /* remembers the frequency adjustment */
-	struct timestamp_event_queue tsevq; /* simple fifo for time stamps */
+	struct list_head tsevqs; /* timestamp fifo list */
 	struct mutex tsevq_mux; /* one process at a time reading the fifo */
 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
 	wait_queue_head_t tsev_wq;

index 6e4d5456a885..2675f383cd0a 100644
@@ -75,12 +75,16 @@ static ssize_t extts_fifo_show(struct device *dev,
 			       struct device_attribute *attr, char *page)
 {
 	struct ptp_clock *ptp = dev_get_drvdata(dev);
-	struct timestamp_event_queue *queue = &ptp->tsevq;
+	struct timestamp_event_queue *queue;
 	struct ptp_extts_event event;
 	unsigned long flags;
 	size_t qcnt;
 	int cnt = 0;
 
+	/* The sysfs fifo will always draw from the fist queue */
+	queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
+				 qlist);
+
 	memset(&event, 0, sizeof(event));
 
 	if (mutex_lock_interruptible(&ptp->tsevq_mux))

index aa1990d2ab46..abe94bb80cf6 100644
@@ -103,6 +103,31 @@ int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
 
 int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 {
+	struct ptp_clock *ptp =
+		container_of(pccontext->clk, struct ptp_clock, clock);
+	struct timestamp_event_queue *queue;
+
+	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
+	if (!queue)
+		return -EINVAL;
+	spin_lock_init(&queue->lock);
+	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	pccontext->private_clkdata = queue;
+	return 0;
+}
+
+int ptp_release(struct posix_clock_context *pccontext)
+{
+	struct timestamp_event_queue *queue = pccontext->private_clkdata;
+	unsigned long flags;
+
+	if (queue) {
+		pccontext->private_clkdata = NULL;
+		spin_lock_irqsave(&queue->lock, flags);
+		list_del(&queue->qlist);
+		spin_unlock_irqrestore(&queue->lock, flags);
+		kfree(queue);
+	}
 	return 0;
 }
 

@@ -441,10 +466,11 @@ __poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp,
 		container_of(pccontext->clk, struct ptp_clock, clock);
 	struct timestamp_event_queue *queue;
 
-	poll_wait(fp, &ptp->tsev_wq, wait);
+	queue = pccontext->private_clkdata;
+	if (!queue)
+		return EPOLLERR;
 
-	/* Extract only the first element in the queue list */
-	queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue, qlist);
+	poll_wait(fp, &ptp->tsev_wq, wait);
 
 	return queue_cnt(queue) ? EPOLLIN : 0;
 }

@@ -462,36 +488,36 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 	size_t qcnt, i;
 	int result;
 
-	/* Extract only the first element in the queue list */
-	queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
-				 qlist);
+	queue = pccontext->private_clkdata;
+	if (!queue) {
+		result = -EINVAL;
+		goto exit;
+	}
 
-	if (cnt % sizeof(struct ptp_extts_event) != 0)
-		return -EINVAL;
+	if (cnt % sizeof(struct ptp_extts_event) != 0) {
+		result = -EINVAL;
+		goto exit;
+	}
 
 	if (cnt > EXTTS_BUFSIZE)
 		cnt = EXTTS_BUFSIZE;
 
 	cnt = cnt / sizeof(struct ptp_extts_event);
 
-	if (mutex_lock_interruptible(&ptp->tsevq_mux))
-		return -ERESTARTSYS;
-
 	if (wait_event_interruptible(ptp->tsev_wq,
 				     ptp->defunct || queue_cnt(queue))) {
-		mutex_unlock(&ptp->tsevq_mux);
 		return -ERESTARTSYS;
 	}
 
 	if (ptp->defunct) {
-		mutex_unlock(&ptp->tsevq_mux);
-		return -ENODEV;
+		result = -ENODEV;
+		goto exit;
 	}
 
 	event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
 	if (!event) {
-		mutex_unlock(&ptp->tsevq_mux);
-		return -ENOMEM;
+		result = -ENOMEM;
+		goto exit;
 	}
 
 	spin_lock_irqsave(&queue->lock, flags);

@@ -510,12 +536,16 @@ ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 
 	cnt = cnt * sizeof(struct ptp_extts_event);
 
-	mutex_unlock(&ptp->tsevq_mux);
-
 	result = cnt;
-	if (copy_to_user(buf, event, cnt))
+	if (copy_to_user(buf, event, cnt)) {
 		result = -EFAULT;
+		goto free_event;
+	}
 
+free_event:
 	kfree(event);
+exit:
+	if (result < 0)
+		ptp_release(pccontext);
 	return result;
 }

index 157ef25bc1b1..74f1ce2dbccb 100644
@@ -162,6 +162,7 @@ static struct posix_clock_operations ptp_clock_ops = {
 	.clock_settime	= ptp_clock_settime,
 	.ioctl		= ptp_ioctl,
 	.open		= ptp_open,
+	.release	= ptp_release,
 	.poll		= ptp_poll,
 	.read		= ptp_read,
 };

@@ -174,7 +175,6 @@ static void ptp_clock_release(struct device *dev)
 
 	ptp_cleanup_pin_groups(ptp);
 	kfree(ptp->vclock_index);
-	mutex_destroy(&ptp->tsevq_mux);
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
 	/* Delete first entry */

@@ -242,9 +242,8 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 	if (!queue)
 		goto no_memory_queue;
-	spin_lock_init(&queue->lock);
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
-	mutex_init(&ptp->tsevq_mux);
+	spin_lock_init(&queue->lock);
 	mutex_init(&ptp->pincfg_mux);
 	mutex_init(&ptp->n_vclocks_mux);
 	init_waitqueue_head(&ptp->tsev_wq);

@@ -345,7 +344,6 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (ptp->kworker)
 		kthread_destroy_worker(ptp->kworker);
 kworker_err:
-	mutex_destroy(&ptp->tsevq_mux);
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
 	list_del(&queue->qlist);

index cc8186a92eec..9d5f3d95058e 100644
@@ -38,7 +38,6 @@ struct ptp_clock {
 	struct pps_device *pps_source;
 	long dialed_frequency; /* remembers the frequency adjustment */
 	struct list_head tsevqs; /* timestamp fifo list */
-	struct mutex tsevq_mux; /* one process at a time reading the fifo */
 	struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
 	wait_queue_head_t tsev_wq;
 	int defunct; /* tells readers to go away when clock is being removed */

index 2675f383cd0a..7d023d9d0acb 100644
@@ -81,15 +81,15 @@ static ssize_t extts_fifo_show(struct device *dev,
 	size_t qcnt;
 	int cnt = 0;
 
+	cnt = list_count_nodes(&ptp->tsevqs);
+	if (cnt <= 0)
+		goto out;
+
 	/* The sysfs fifo will always draw from the fist queue */
 	queue = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
 				 qlist);
 
 	memset(&event, 0, sizeof(event));
-
-	if (mutex_lock_interruptible(&ptp->tsevq_mux))
-		return -ERESTARTSYS;
-
 	spin_lock_irqsave(&queue->lock, flags);
 	qcnt = queue_cnt(queue);
 	if (qcnt) {

@@ -104,7 +104,6 @@ static ssize_t extts_fifo_show(struct device *dev,
 	cnt = snprintf(page, PAGE_SIZE, "%u %lld %u\n",
 		       event.index, event.t.sec, event.t.nsec);
 out:
-	mutex_unlock(&ptp->tsevq_mux);
 	return cnt;
 }
 static DEVICE_ATTR(fifo, 0444, extts_fifo_show, NULL);

index abe94bb80cf6..ac2f2b5ea0b7 100644
@@ -110,6 +110,12 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 	if (!queue)
 		return -EINVAL;
+	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
+	if (!queue->mask) {
+		kfree(queue);
+		return -EINVAL;
+	}
+	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 	spin_lock_init(&queue->lock);
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
 	pccontext->private_clkdata = queue;

@@ -126,6 +132,7 @@ int ptp_release(struct posix_clock_context *pccontext)
 		spin_lock_irqsave(&queue->lock, flags);
 		list_del(&queue->qlist);
 		spin_unlock_irqrestore(&queue->lock, flags);
+		bitmap_free(queue->mask);
 		kfree(queue);
 	}
 	return 0;

@@ -141,6 +148,7 @@ long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
 	struct system_device_crosststamp xtstamp;
 	struct ptp_clock_info *ops = ptp->info;
 	struct ptp_sys_offset *sysoff = NULL;
+	struct timestamp_event_queue *tsevq;
 	struct ptp_system_timestamp sts;
 	struct ptp_clock_request req;
 	struct ptp_clock_caps caps;

@@ -150,6 +158,8 @@ long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
 	struct timespec64 ts;
 	int enable, err = 0;
 
+	tsevq = pccontext->private_clkdata;
+
 	switch (cmd) {
 
 	case PTP_CLOCK_GETCAPS:

@@ -448,6 +458,22 @@ long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
 		mutex_unlock(&ptp->pincfg_mux);
 		break;
 
+	case PTP_MASK_CLEAR_ALL:
+		bitmap_clear(tsevq->mask, 0, PTP_MAX_CHANNELS);
+		break;
+
+	case PTP_MASK_EN_SINGLE:
+		if (copy_from_user(&i, (void __user *)arg, sizeof(i))) {
+			err = -EFAULT;
+			break;
+		}
+		if (i >= PTP_MAX_CHANNELS) {
+			err = -EFAULT;
+			break;
+		}
+		set_bit(i, tsevq->mask);
+		break;
+
 	default:
 		err = -ENOTTY;
 		break;

index 74f1ce2dbccb..ed16d9787ce9 100644
@@ -183,6 +183,7 @@ static void ptp_clock_release(struct device *dev)
 	spin_lock_irqsave(&tsevq->lock, flags);
 	list_del(&tsevq->qlist);
 	spin_unlock_irqrestore(&tsevq->lock, flags);
+	bitmap_free(tsevq->mask);
 	kfree(tsevq);
 	ida_free(&ptp_clocks_map, ptp->index);
 	kfree(ptp);

@@ -243,6 +244,10 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	if (!queue)
 		goto no_memory_queue;
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
+	queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
+	if (!queue->mask)
+		goto no_memory_bitmap;
+	bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 	spin_lock_init(&queue->lock);
 	mutex_init(&ptp->pincfg_mux);
 	mutex_init(&ptp->n_vclocks_mux);

@@ -346,6 +351,8 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 kworker_err:
 	mutex_destroy(&ptp->pincfg_mux);
 	mutex_destroy(&ptp->n_vclocks_mux);
+	bitmap_free(queue->mask);
+no_memory_bitmap:
 	list_del(&queue->qlist);
 	kfree(queue);
 no_memory_queue:

@@ -400,9 +407,10 @@ void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 		break;
 
 	case PTP_CLOCK_EXTTS:
-		/* Enqueue timestamp on all queues */
+		/* Enqueue timestamp on selected queues */
 		list_for_each_entry(tsevq, &ptp->tsevqs, qlist) {
-			enqueue_external_timestamp(tsevq, event);
+			if (test_bit((unsigned int)event->index, tsevq->mask))
+				enqueue_external_timestamp(tsevq, event);
 		}
 		wake_up_interruptible(&ptp->tsev_wq);
 		break;

index 9d5f3d95058e..ad4ce1b25c86 100644
@@ -16,10 +16,12 @@
 #include <linux/ptp_clock_kernel.h>
 #include <linux/time.h>
 #include <linux/list.h>
+#include <linux/bitmap.h>
 
 #define PTP_MAX_TIMESTAMPS 128
 #define PTP_BUF_TIMESTAMPS 30
 #define PTP_DEFAULT_MAX_VCLOCKS 20
+#define PTP_MAX_CHANNELS 2048
 
 struct timestamp_event_queue {
 	struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS];

@@ -27,6 +29,7 @@ struct timestamp_event_queue {
 	int tail;
 	spinlock_t lock;
 	struct list_head qlist;
+	unsigned long *mask;
 };
 
 struct ptp_clock {

index 05cc35fc94ac..da700999cad4 100644
@@ -224,6 +224,8 @@ struct ptp_pin_desc {
 	_IOWR(PTP_CLK_MAGIC, 17, struct ptp_sys_offset_precise)
 #define PTP_SYS_OFFSET_EXTENDED2 \
 	_IOWR(PTP_CLK_MAGIC, 18, struct ptp_sys_offset_extended)
+#define PTP_MASK_CLEAR_ALL  _IO(PTP_CLK_MAGIC, 19)
+#define PTP_MASK_EN_SINGLE  _IOW(PTP_CLK_MAGIC, 20, unsigned int)
 
 struct ptp_extts_event {
 	struct ptp_clock_time t; /* Time event occured. */

index ac2f2b5ea0b7..282cd7d24077 100644
@@ -10,6 +10,7 @@
 #include <linux/sched.h>
 #include <linux/slab.h>
 #include <linux/timekeeping.h>
+#include <linux/debugfs.h>
 
 #include <linux/nospec.h>
 

@@ -106,6 +107,7 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 	struct ptp_clock *ptp =
 		container_of(pccontext->clk, struct ptp_clock, clock);
 	struct timestamp_event_queue *queue;
+	char debugfsname[32];
 
 	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 	if (!queue)

@@ -119,6 +121,17 @@ int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 	spin_lock_init(&queue->lock);
 	list_add_tail(&queue->qlist, &ptp->tsevqs);
 	pccontext->private_clkdata = queue;
+
+	/* Debugfs contents */
+	sprintf(debugfsname, "0x%p", queue);
+	queue->debugfs_instance =
+		debugfs_create_dir(debugfsname, ptp->debugfs_root);
+	queue->dfs_bitmap.array = (u32 *)queue->mask;
+	queue->dfs_bitmap.n_elements =
+		DIV_ROUND_UP(PTP_MAX_CHANNELS, BITS_PER_BYTE * sizeof(u32));
+	debugfs_create_u32_array("mask", 0444, queue->debugfs_instance,
+				 &queue->dfs_bitmap);
+
 	return 0;
 }
 

@@ -128,6 +141,7 @@ int ptp_release(struct posix_clock_context *pccontext)
 	unsigned long flags;
 
 	if (queue) {
+		debugfs_remove(queue->debugfs_instance);
 		pccontext->private_clkdata = NULL;
 		spin_lock_irqsave(&queue->lock, flags);
 		list_del(&queue->qlist);

index ed16d9787ce9..2e801cd33220 100644
@@ -15,6 +15,7 @@
 #include <linux/slab.h>
 #include <linux/syscalls.h>
 #include <linux/uaccess.h>
+#include <linux/debugfs.h>
 #include <uapi/linux/sched/types.h>
 
 #include "ptp_private.h"

@@ -185,6 +186,7 @@ static void ptp_clock_release(struct device *dev)
 	spin_unlock_irqrestore(&tsevq->lock, flags);
 	bitmap_free(tsevq->mask);
 	kfree(tsevq);
+	debugfs_remove(ptp->debugfs_root);
 	ida_free(&ptp_clocks_map, ptp->index);
 	kfree(ptp);
 }

@@ -218,6 +220,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 	struct ptp_clock *ptp;
 	struct timestamp_event_queue *queue = NULL;
 	int err = 0, index, major = MAJOR(ptp_devt);
+	char debugfsname[8];
 	size_t size;
 
 	if (info->n_alarm > PTP_MAX_ALARMS)

@@ -339,6 +342,10 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 		return ERR_PTR(err);
 	}
 
+	/* Debugfs initialization */
+	sprintf(debugfsname, "ptp%d", ptp->index);
+	ptp->debugfs_root = debugfs_create_dir(debugfsname, NULL);
+
 	return ptp;
 
 no_pps:

index ad4ce1b25c86..52f87e394aa6 100644
@@ -17,6 +17,7 @@
 #include <linux/time.h>
 #include <linux/list.h>
 #include <linux/bitmap.h>
+#include <linux/debugfs.h>
 
 #define PTP_MAX_TIMESTAMPS 128
 #define PTP_BUF_TIMESTAMPS 30

@@ -30,6 +31,8 @@ struct timestamp_event_queue {
 	spinlock_t lock;
 	struct list_head qlist;
 	unsigned long *mask;
+	struct dentry *debugfs_instance;
+	struct debugfs_u32_array dfs_bitmap;
 };
 
 struct ptp_clock {

@@ -57,6 +60,7 @@ struct ptp_clock {
 	struct mutex n_vclocks_mux; /* protect concurrent n_vclocks access */
 	bool is_virtual_clock;
 	bool has_cycles;
+	struct dentry *debugfs_root;
 };
 
 #define info_to_vclock(d) container_of((d), struct ptp_vclock, info)

index c9f6cca4feb4..011252fe238c 100644
@@ -121,6 +121,7 @@ static void usage(char *progname)
 		" -d name    device to open\n"
 		" -e val     read 'val' external time stamp events\n"
 		" -f val     adjust the ptp clock frequency by 'val' ppb\n"
+		" -F chan    Enable single channel mask and keep device open for debugfs verification.\n"
 		" -g         get the ptp clock time\n"
 		" -h         prints this message\n"
 		" -i val     index for event/trigger\n"

@@ -187,6 +188,7 @@ int main(int argc, char *argv[])
 	int pps = -1;
 	int seconds = 0;
 	int settime = 0;
+	int channel = -1;
 
 	int64_t t1, t2, tp;
 	int64_t interval, offset;

@@ -196,7 +198,7 @@ int main(int argc, char *argv[])
 
 	progname = strrchr(argv[0], '/');
 	progname = progname ? 1+progname : argv[0];
-	while (EOF != (c = getopt(argc, argv, "cd:e:f:ghH:i:k:lL:n:o:p:P:sSt:T:w:x:Xz"))) {
+	while (EOF != (c = getopt(argc, argv, "cd:e:f:F:ghH:i:k:lL:n:o:p:P:sSt:T:w:x:Xz"))) {
 		switch (c) {
 		case 'c':
 			capabilities = 1;

@@ -210,6 +212,9 @@ int main(int argc, char *argv[])
 		case 'f':
 			adjfreq = atoi(optarg);
 			break;
+		case 'F':
+			channel = atoi(optarg);
+			break;
 		case 'g':
 			gettime = 1;
 			break;

@@ -604,6 +609,18 @@ int main(int argc, char *argv[])
 		free(xts);
 	}
 
+	if (channel >= 0) {
+		if (ioctl(fd, PTP_MASK_CLEAR_ALL)) {
+			perror("PTP_MASK_CLEAR_ALL");
+		} else if (ioctl(fd, PTP_MASK_EN_SINGLE, (unsigned int *)&channel)) {
+			perror("PTP_MASK_EN_SINGLE");
+		} else {
+			printf("Channel %d exclusively enabled. Check on debugfs.\n", channel);
+			printf("Press any key to continue\n.");
+			getchar();
+		}
+	}
+
 	close(fd);
 	return 0;
 }