ptp: support event queue reader channel masks

On systems with multiple timestamp event channels, some readers might
want to receive only a subset of those channels.

Add the necessary modifications to support timestamp event channel
filtering, including two IOCTL operations:

- Clear all channels
- Enable one channel

The mask modification operations will be applied exclusively on the
event queue assigned to the file descriptor used on the IOCTL operation,
so the typical procedure to have a reader receiving only a subset of the
enabled channels would be:

- Open device file
- ioctl: clear all channels
- ioctl: enable one channel
- start reading

Calling the enable one channel ioctl more than once will result in
multiple enabled channels.

Signed-off-by: Xabier Marquiegui <reibax@gmail.com>
Suggested-by: Richard Cochran <richardcochran@gmail.com>
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/ptp/ptp_chardev.c b/drivers/ptp/ptp_chardev.c
index abe94bb80cf6f100d1bb4e33b63e21c97f1a77d5..ac2f2b5ea0b7835d15a47e37cb555c9bb931e266 100644 (file)
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -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;

diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 74f1ce2dbccb47a35c2b96801e2822688b0aa09b..ed16d9787ce93e64f72ebf305170074fdf9fea1b 100644 (file)
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -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 @@ no_mem_for_vclocks:
 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;

diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 9d5f3d95058ec20b1af97af858f36a116eded820..ad4ce1b25c86c77c02f3ba75fd4a98f9ad6ba344 100644 (file)
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -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 {

diff --git a/include/uapi/linux/ptp_clock.h b/include/uapi/linux/ptp_clock.h
index 05cc35fc94acf8124268e4b222fcaa88a7809759..da700999cad4a259a3ace7057ec2331d4412ce81 100644 (file)
--- a/include/uapi/linux/ptp_clock.h
+++ b/include/uapi/linux/ptp_clock.h
@@ -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. */