Support ptp physical/virtual clocks conversion via sysfs. There will be a new attribute n_vclocks under ptp physical clock sysfs.
- In default, the value is 0 meaning only ptp physical clock is in use. - Setting the value can create corresponding number of ptp virtual clocks to use. But current physical clock is guaranteed to stay free running. - Setting the value back to 0 can delete virtual clocks and back use physical clock again.
Another new attribute max_vclocks control the maximum number of ptp vclocks.
Signed-off-by: Yangbo Lu yangbo.lu@nxp.com --- Changes for v2: - Split from v1 patch #2. - Converted to num_vclocks for creating virtual clocks. - Guranteed physical clock free running when using virtual clocks. - Fixed build warning. - Updated copyright. Changes for v3: - Protected concurrency of ptp->num_vclocks accessing. Changes for v4: - Rephrased description in doc. - Used unsigned int for vclocks number, and max_vclocks for limitiation. - Fixed mutex locking. - Other minor fixes. Changes for v5: - Fixed checkpatch. - Checked pointer parent->class->name. --- Documentation/ABI/testing/sysfs-ptp | 20 ++++ drivers/ptp/ptp_clock.c | 26 ++++++ drivers/ptp/ptp_private.h | 21 +++++ drivers/ptp/ptp_sysfs.c | 138 ++++++++++++++++++++++++++++ 4 files changed, 205 insertions(+)
diff --git a/Documentation/ABI/testing/sysfs-ptp b/Documentation/ABI/testing/sysfs-ptp index 2363ad810ddb..d378f57c1b73 100644 --- a/Documentation/ABI/testing/sysfs-ptp +++ b/Documentation/ABI/testing/sysfs-ptp @@ -33,6 +33,13 @@ Description: frequency adjustment value (a positive integer) in parts per billion.
+What: /sys/class/ptp/ptpN/max_vclocks +Date: May 2021 +Contact: Yangbo Lu yangbo.lu@nxp.com +Description: + This file contains the maximum number of ptp vclocks. + Write integer to re-configure it. + What: /sys/class/ptp/ptpN/n_alarms Date: September 2010 Contact: Richard Cochran richardcochran@gmail.com @@ -61,6 +68,19 @@ Description: This file contains the number of programmable pins offered by the PTP hardware clock.
+What: /sys/class/ptp/ptpN/n_vclocks +Date: May 2021 +Contact: Yangbo Lu yangbo.lu@nxp.com +Description: + This file contains the number of virtual PTP clocks in + use. By default, the value is 0 meaning that only the + physical clock is in use. Setting the value creates + the corresponding number of virtual clocks and causes + the physical clock to become free running. Setting the + value back to 0 deletes the virtual clocks and + switches the physical clock back to normal, adjustable + operation. + What: /sys/class/ptp/ptpN/pins Date: March 2014 Contact: Richard Cochran richardcochran@gmail.com diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c index a23a37a4d5dc..7334f478dde7 100644 --- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -76,6 +76,11 @@ static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp { struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
+ if (ptp_vclock_in_use(ptp)) { + pr_err("ptp: virtual clock in use\n"); + return -EBUSY; + } + return ptp->info->settime64(ptp->info, tp); }
@@ -97,6 +102,11 @@ static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx) struct ptp_clock_info *ops; int err = -EOPNOTSUPP;
+ if (ptp_vclock_in_use(ptp)) { + pr_err("ptp: virtual clock in use\n"); + return -EBUSY; + } + ops = ptp->info;
if (tx->modes & ADJ_SETOFFSET) { @@ -161,6 +171,7 @@ static void ptp_clock_release(struct device *dev) ptp_cleanup_pin_groups(ptp); mutex_destroy(&ptp->tsevq_mux); mutex_destroy(&ptp->pincfg_mux); + mutex_destroy(&ptp->n_vclocks_mux); ida_simple_remove(&ptp_clocks_map, ptp->index); kfree(ptp); } @@ -208,6 +219,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, spin_lock_init(&ptp->tsevq.lock); mutex_init(&ptp->tsevq_mux); mutex_init(&ptp->pincfg_mux); + mutex_init(&ptp->n_vclocks_mux); init_waitqueue_head(&ptp->tsev_wq);
if (ptp->info->do_aux_work) { @@ -221,6 +233,14 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, ptp->pps_source->lookup_cookie = ptp; }
+ /* PTP virtual clock is being registered under physical clock */ + if (parent->class && parent->class->name && + strcmp(parent->class->name, "ptp") == 0) + ptp->is_virtual_clock = true; + + if (!ptp->is_virtual_clock) + ptp->max_vclocks = PTP_DEFAULT_MAX_VCLOCKS; + err = ptp_populate_pin_groups(ptp); if (err) goto no_pin_groups; @@ -270,6 +290,7 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, kworker_err: mutex_destroy(&ptp->tsevq_mux); mutex_destroy(&ptp->pincfg_mux); + mutex_destroy(&ptp->n_vclocks_mux); ida_simple_remove(&ptp_clocks_map, index); no_slot: kfree(ptp); @@ -280,6 +301,11 @@ EXPORT_SYMBOL(ptp_clock_register);
int ptp_clock_unregister(struct ptp_clock *ptp) { + if (ptp_vclock_in_use(ptp)) { + pr_err("ptp: virtual clock in use\n"); + return -EBUSY; + } + ptp->defunct = 1; wake_up_interruptible(&ptp->tsev_wq);
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h index 853b79b6b30e..87cb55953b69 100644 --- a/drivers/ptp/ptp_private.h +++ b/drivers/ptp/ptp_private.h @@ -18,6 +18,7 @@
#define PTP_MAX_TIMESTAMPS 128 #define PTP_BUF_TIMESTAMPS 30 +#define PTP_DEFAULT_MAX_VCLOCKS 20
struct timestamp_event_queue { struct ptp_extts_event buf[PTP_MAX_TIMESTAMPS]; @@ -46,6 +47,10 @@ struct ptp_clock { const struct attribute_group *pin_attr_groups[2]; struct kthread_worker *kworker; struct kthread_delayed_work aux_work; + unsigned int max_vclocks; + unsigned int n_vclocks; + struct mutex n_vclocks_mux; /* protect concurrent n_vclocks access */ + bool is_virtual_clock; };
#define info_to_vclock(d) container_of((d), struct ptp_vclock, info) @@ -74,6 +79,22 @@ static inline int queue_cnt(struct timestamp_event_queue *q) return cnt < 0 ? PTP_MAX_TIMESTAMPS + cnt : cnt; }
+/* Check if ptp virtual clock is in use */ +static inline bool ptp_vclock_in_use(struct ptp_clock *ptp) +{ + bool in_use = false; + + if (mutex_lock_interruptible(&ptp->n_vclocks_mux)) + return true; + + if (!ptp->is_virtual_clock && ptp->n_vclocks) + in_use = true; + + mutex_unlock(&ptp->n_vclocks_mux); + + return in_use; +} + /* * see ptp_chardev.c */ diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c index be076a91e20e..0b05041783a5 100644 --- a/drivers/ptp/ptp_sysfs.c +++ b/drivers/ptp/ptp_sysfs.c @@ -3,6 +3,7 @@ * PTP 1588 clock support - sysfs interface. * * Copyright (C) 2010 OMICRON electronics GmbH + * Copyright 2021 NXP */ #include <linux/capability.h> #include <linux/slab.h> @@ -148,6 +149,137 @@ static ssize_t pps_enable_store(struct device *dev, } static DEVICE_ATTR(pps_enable, 0220, NULL, pps_enable_store);
+static int unregister_vclock(struct device *dev, void *data) +{ + struct ptp_clock *ptp = dev_get_drvdata(dev); + struct ptp_clock_info *info = ptp->info; + struct ptp_vclock *vclock; + u8 *num = data; + + vclock = info_to_vclock(info); + dev_info(dev->parent, "delete virtual clock ptp%d\n", + vclock->clock->index); + + ptp_vclock_unregister(vclock); + (*num)--; + + /* For break. Not error. */ + if (*num == 0) + return -EINVAL; + + return 0; +} + +static ssize_t n_vclocks_show(struct device *dev, + struct device_attribute *attr, char *page) +{ + struct ptp_clock *ptp = dev_get_drvdata(dev); + ssize_t size; + + if (mutex_lock_interruptible(&ptp->n_vclocks_mux)) + return -ERESTARTSYS; + + size = snprintf(page, PAGE_SIZE - 1, "%d\n", ptp->n_vclocks); + + mutex_unlock(&ptp->n_vclocks_mux); + + return size; +} + +static ssize_t n_vclocks_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct ptp_clock *ptp = dev_get_drvdata(dev); + struct ptp_vclock *vclock; + int err = -EINVAL; + u32 num, i; + + if (kstrtou32(buf, 0, &num)) + return err; + + if (mutex_lock_interruptible(&ptp->n_vclocks_mux)) + return -ERESTARTSYS; + + if (num > ptp->max_vclocks) { + dev_err(dev, "max value is %d\n", ptp->max_vclocks); + goto out; + } + + /* Need to create more vclocks */ + if (num > ptp->n_vclocks) { + for (i = 0; i < num - ptp->n_vclocks; i++) { + vclock = ptp_vclock_register(ptp); + if (!vclock) + goto out; + + dev_info(dev, "new virtual clock ptp%d\n", + vclock->clock->index); + } + } + + /* Need to delete vclocks */ + if (num < ptp->n_vclocks) { + i = ptp->n_vclocks - num; + device_for_each_child_reverse(dev, &i, + unregister_vclock); + } + + if (num == 0) + dev_info(dev, "only physical clock in use now\n"); + else + dev_info(dev, "guarantee physical clock free running\n"); + + ptp->n_vclocks = num; + mutex_unlock(&ptp->n_vclocks_mux); + + return count; +out: + mutex_unlock(&ptp->n_vclocks_mux); + return err; +} +static DEVICE_ATTR_RW(n_vclocks); + +static ssize_t max_vclocks_show(struct device *dev, + struct device_attribute *attr, char *page) +{ + struct ptp_clock *ptp = dev_get_drvdata(dev); + ssize_t size; + + size = snprintf(page, PAGE_SIZE - 1, "%d\n", ptp->max_vclocks); + + return size; +} + +static ssize_t max_vclocks_store(struct device *dev, + struct device_attribute *attr, + const char *buf, size_t count) +{ + struct ptp_clock *ptp = dev_get_drvdata(dev); + u32 max; + + if (kstrtou32(buf, 0, &max) || max == 0) + return -EINVAL; + + if (max == ptp->max_vclocks) + return count; + + if (mutex_lock_interruptible(&ptp->n_vclocks_mux)) + return -ERESTARTSYS; + + if (max < ptp->n_vclocks) { + mutex_unlock(&ptp->n_vclocks_mux); + return -EINVAL; + } + + ptp->max_vclocks = max; + + mutex_unlock(&ptp->n_vclocks_mux); + + return count; +} +static DEVICE_ATTR_RW(max_vclocks); + static struct attribute *ptp_attrs[] = { &dev_attr_clock_name.attr,
@@ -162,6 +294,8 @@ static struct attribute *ptp_attrs[] = { &dev_attr_fifo.attr, &dev_attr_period.attr, &dev_attr_pps_enable.attr, + &dev_attr_n_vclocks.attr, + &dev_attr_max_vclocks.attr, NULL };
@@ -183,6 +317,10 @@ static umode_t ptp_is_attribute_visible(struct kobject *kobj, } else if (attr == &dev_attr_pps_enable.attr) { if (!info->pps) mode = 0; + } else if (attr == &dev_attr_n_vclocks.attr || + attr == &dev_attr_max_vclocks.attr) { + if (ptp->is_virtual_clock) + mode = 0; }
return mode;