This is a note to let you know that I've just added the patch titled
ptp: support multiple timestamp event readers
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ptp-support-multiple-timestamp-event-readers.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 71884617a75ed903c04c09be4f759f634e9127f0
Author: Xabier Marquiegui <reibax@xxxxxxxxx>
Date: Thu Oct 12 00:39:55 2023 +0200
ptp: support multiple timestamp event readers
[ Upstream commit 8f5de6fb245326704f37d91780b9a10253a8a100 ]
Use linked lists to create one event queue per open file. This enables
simultaneous readers for timestamp event queues.
Signed-off-by: Xabier Marquiegui <reibax@xxxxxxxxx>
Suggested-by: Richard Cochran <richardcochran@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Stable-dep-of: 19ae40f572a9 ("ptp: Properly handle compat ioctls")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index 82b5a68d1ca34..3c795fee49262 100644
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -104,6 +104,31 @@ 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;
}
@@ -439,10 +464,11 @@ __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;
}
@@ -460,36 +486,36 @@ 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);
@@ -509,12 +535,16 @@ 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;
}
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index ff40f902f706f..c677a45474360 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -163,6 +163,7 @@ 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,
};
@@ -175,7 +176,6 @@ 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 */
@@ -235,9 +235,8 @@ 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);
@@ -323,7 +322,6 @@ 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);
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index a469623f22751..baee5123dc22f 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -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 */
diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c
index 2b2caca45a7d7..5986cb0c502c9 100644
--- a/drivers/ptp/ptp_sysfs.c
+++ b/drivers/ptp/ptp_sysfs.c
@@ -70,15 +70,15 @@ 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) {
@@ -94,7 +94,6 @@ 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);
