ptp: add debugfs interface to see applied channel masks

Use debugfs to be able to view channel mask applied to every timestamp
event queue.

Every time the device is opened, a new entry is created in
`$DEBUGFS_MOUNTPOINT/ptpN/$INSTANCE_ADDRESS/mask`.

The mask value can be viewed grouped in 32bit decimal values using cat,
or converted to hexadecimal with the included `ptpchmaskfmt.sh` script.
32 bit values are listed from least significant to most significant.

Signed-off-by: Xabier Marquiegui <reibax@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 ac2f2b5ea0b7835d15a47e37cb555c9bb931e266..282cd7d24077389780268d6ed8ee96a69041d84b 100644 (file)
--- a/drivers/ptp/ptp_chardev.c
+++ b/drivers/ptp/ptp_chardev.c
@@ -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);

diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index ed16d9787ce93e64f72ebf305170074fdf9fea1b..2e801cd3322005dd24cc06a8d0e5eff2e7273eef 100644 (file)
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -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:

diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index ad4ce1b25c86c77c02f3ba75fd4a98f9ad6ba344..52f87e394aa641ffb434fa98fd7c39b6a8d1fd07 100644 (file)
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -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)

diff --git a/tools/testing/selftests/ptp/ptpchmaskfmt.sh b/tools/testing/selftests/ptp/ptpchmaskfmt.sh
new file mode 100644 (file)
index 0000000..0a06ba8
--- /dev/null
+++ b/tools/testing/selftests/ptp/ptpchmaskfmt.sh
@@ -0,0 +1,14 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+
+# Simple helper script to transform ptp debugfs timestamp event queue filtering
+# masks from decimal values to hexadecimal values
+
+# Only takes the debugfs mask file path as an argument
+DEBUGFS_MASKFILE="${1}"
+
+#shellcheck disable=SC2013,SC2086
+for int in $(cat "$DEBUGFS_MASKFILE") ; do
+    printf '0x%08X ' "$int"
+done
+echo