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authorLinus Torvalds <torvalds@linux-foundation.org>2026-09-13 12:27:00 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-09-13 12:27:00 -0700
commit22098763a10d9c1340827fcf6edab66f153b27f0 (patch)
tree3962f95a34df034652ff93686cdd156c7197f2d9 /drivers/pps/generators
downloadlinux-stable-22098763a10d9c1340827fcf6edab66f153b27f0.tar.gz
linux-stable-22098763a10d9c1340827fcf6edab66f153b27f0.zip
Merge tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted
Pull tracing fixes from Steven Rostedt: - Don't destroy user event fields when removal fails User event fields are destroyed before the event is removed from visibility. But that can fail leaving the still visible event with no fields. Move the destroying of the fields to after the event is successfully removed from visibility. - Initialize function graph state is fork before calling copy_exec_state() For non-CLONE_VM forks, copy_exec_state() allocates a new task_exec_state. If that allocation fails, ftrace_graph_exit_task() will free the tasks ret_stack pointer. Since that pointer is still using the parent's ret_stack, it mistakenly frees the parent's pointer too. Call ftrace_graph_init() on the task first which will NULL out the new tasks's ret_stack and if the copy fails, it will not free anything. - Remove FGRAPH_MAX_INDEX The macro FGRAPH_MAX_INDEX was added but never used. Remove it. - Save ent_size in function graph printing of nested functions The function graph tracer needs to look at the next event to see if the next event is the return of the current function entry. If it is, it prints a single line: ktime_get(); Otherwise it prints it like a nested function: tick_nohz_irq_exit() { ktime_get(); kcpustat_irq_exit(); } In order to look at the next event, it must save the current event so that it has the information to print from it. It saves the event in the iterator descriptor called "ent". What it doesn't save is the ent_size of the event which is now used to know if the function graph arguments are to be printed. The peek doesn't save the size so the size used happens to be that of the size of the last event that was seen. Save the entry event size in the iterator descriptor so that the correct size is used. - Fix several errors with freeing data in the histogram code The histogram code had a lot of leaked or or incorrect accounting when failures happen. Correct them. - Fix histogram regression of .percent and .graph modifiers Up until 6.3 histogram values could have "percent" or "graph" modifiers that changed how they were printed. But a change that added restricting histograms values from being strings, stack traces and other modifiers inadvertently prevented them from using the percent and graph modifiers, which were legal use cases for values. Put back the percent and graph modifiers. - Fix various typos in the comments - Set the trace_clock before initializing a histogram with clock argument The histogram API allows the user to specific which trace clock to use via a "clock=" string. The histogram is set up first before the clock is checked. If the passed in clock is not valid, it exits without fully fixing up the histogram leaving it on the list and a use-after-free can trigger. Update the clock argument first and if it fails then exit gracefully before the histogram trigger is placed on any lists. - Restore :mod: trailer after parsing in ftrace_set_clr_event The function ftrace_set_clr_event() modifies the parse string and needs to put it back to what was passed in. It searches for ":mod:" via a strsep() but fails to put back the first ':' in the string. Add back the ':' in the passed in string. - Take trace_array reference when opening a tracer options file The options files are dynamically created and some tracers add their own options. When a tracer adds their own list of options, the trace_array holding them has an array to hold the list of options for each tracer. This array increases in size via a krealloc(), and the new entry gets a newly allocated array to hold the options of the new tracer being added. The element in each entry of the tracer's option array holds a pointer back to the trace_array, a pointer to the tracer it is associated to, a pointer to the flags of the option. The issue is that these arrays are freed when the trace_array is freed when its instance it represents is removed from the instances directory. There's a race that an open of one of these options files can happen when the instance is being removed. Add a new helper function to be called by the open function of the options file to iterate all existing trace_arrays under a lock and find the one that has the given option element in one of it's tracer arrays. If found, then update the associated trace_array's reference counter to keep it from being freed. If not found, have the open call return -ENODEV. - Disable interrupts when acquiring the lock in rb_wake_up_waiters() The function rb_wake_up_waiters() assumes it will be called in interrupt context and does not disable irqs when taking cpu_buffer->reader_lock, which can be called in hard interrupt context. The issue is in PREEMPT_RT, this function is called in thread context leaving this lock open to a deadlock. Take the lock with interrupts disabled. - Use rcu_assign_pointer() for tmp_ops filter hash The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer() - Fix use-after-free in enable_trigger_private_data_free() The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file. - Fix accounting of buffer data remote headers trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions. - Catch nr_page_va overflow in ring_buffer_desc sizing The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for. - Do not resize the subbuf order if any per_cpu buffer is disabled The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped. * tag 'trace-v7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (25 commits) ring-buffer: Check resize_disabled before publishing the new subbuf order tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing tracing/remotes: Account for ring buffer page header in size calculation tracing: Don't dereference trace_event_file in deferred trigger free ftrace: Use rcu_assign_pointer() for tmp_ops filter hash ring-buffer: Acquire the lock with irqsave in rb_wake_up_waiters() tracing: Take trace_array reference when opening a tracer options file tracing: Fix ring_buffer_read_page_size() kernel-doc tracing: Restore :mod: trailer after parsing in ftrace_set_clr_event() tracing: Fix memory corruption from a "STACKTRACE" histogram key tracing: Fix memory corruption from the histogram stacktrace modifier tracing: Undo the registration when enabling the histogram trigger fails tracing: Take the reference before publishing the named histogram trigger tracing: Set the trace clock before registering the histogram trigger tracing: Fix typo "preceeded" in comment tracing: Fix typo "availabe" in comment tracing: Let histogram values keep the percent and graph modifiers tracing: Keep the entry count when the histogram stats allocation fails tracing: Free histogram the field rejected for a bad modifier tracing: Free histogram the var ref when its initialization fails ...
Diffstat (limited to 'drivers/pps/generators')
-rw-r--r--drivers/pps/generators/Kconfig42
-rw-r--r--drivers/pps/generators/Makefile12
-rw-r--r--drivers/pps/generators/pps_gen-dummy.c92
-rw-r--r--drivers/pps/generators/pps_gen.c346
-rw-r--r--drivers/pps/generators/pps_gen_tio.c267
-rw-r--r--drivers/pps/generators/sysfs.c75
6 files changed, 834 insertions, 0 deletions
diff --git a/drivers/pps/generators/Kconfig b/drivers/pps/generators/Kconfig
new file mode 100644
index 000000000..4ef02b3f2
--- /dev/null
+++ b/drivers/pps/generators/Kconfig
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# PPS generators configuration
+#
+
+menuconfig PPS_GENERATOR
+ tristate "PPS generators support"
+ help
+ PPS generators are special hardware which are able to produce PPS
+ (Pulse Per Second) signals.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pps_gen_core.
+
+if PPS_GENERATOR
+
+config PPS_GENERATOR_DUMMY
+ tristate "Dummy PPS generator (Testing generator, use for debug)"
+ help
+ If you say yes here you get support for a PPS debugging generator
+ (which generates no PPS signal at all).
+
+ This driver can also be built as a module. If so, the module
+ will be called pps_gen-dummy.
+
+config PPS_GENERATOR_TIO
+ tristate "TIO PPS signal generator"
+ depends on X86 && CPU_SUP_INTEL
+ help
+ If you say yes here you get support for a PPS TIO signal generator
+ which generates a pulse at a prescribed time based on the system clock.
+ It uses time translation and hrtimers to precisely generate a pulse.
+ This hardware is present on 2019 and newer Intel CPUs. However, this
+ driver is not useful without adding highly specialized hardware outside
+ the Linux system to observe these pulses.
+
+ To compile this driver as a module, choose M here: the module
+ will be called pps_gen_tio.
+
+ If unsure, say N.
+
+endif # PPS_GENERATOR
diff --git a/drivers/pps/generators/Makefile b/drivers/pps/generators/Makefile
new file mode 100644
index 000000000..5d38774b4
--- /dev/null
+++ b/drivers/pps/generators/Makefile
@@ -0,0 +1,12 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for PPS generators.
+#
+
+pps_gen_core-y := pps_gen.o sysfs.o
+obj-$(CONFIG_PPS_GENERATOR) := pps_gen_core.o
+
+obj-$(CONFIG_PPS_GENERATOR_DUMMY) += pps_gen-dummy.o
+obj-$(CONFIG_PPS_GENERATOR_TIO) += pps_gen_tio.o
+
+ccflags-$(CONFIG_PPS_DEBUG) := -DDEBUG
diff --git a/drivers/pps/generators/pps_gen-dummy.c b/drivers/pps/generators/pps_gen-dummy.c
new file mode 100644
index 000000000..a4395543c
--- /dev/null
+++ b/drivers/pps/generators/pps_gen-dummy.c
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PPS dummy generator
+ *
+ * Copyright (C) 2024 Rodolfo Giometti <giometti@enneenne.com>
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/time.h>
+#include <linux/timer.h>
+#include <linux/random.h>
+#include <linux/pps_gen_kernel.h>
+
+static struct pps_gen_device *pps_gen;
+static struct timer_list ktimer;
+
+static unsigned int get_random_delay(void)
+{
+ unsigned int delay = get_random_u8() & 0x0f;
+
+ return (delay + 1) * HZ;
+}
+
+/*
+ * The kernel timer
+ */
+
+static void pps_gen_ktimer_event(struct timer_list *unused)
+{
+ pps_gen_event(pps_gen, PPS_GEN_EVENT_MISSEDPULSE, NULL);
+}
+
+/*
+ * PPS Generator methods
+ */
+
+static int pps_gen_dummy_get_time(struct pps_gen_device *pps_gen,
+ struct timespec64 *time)
+{
+ ktime_get_real_ts64(time);
+ return 0;
+}
+
+static int pps_gen_dummy_enable(struct pps_gen_device *pps_gen, bool enable)
+{
+ if (enable)
+ mod_timer(&ktimer, jiffies + get_random_delay());
+ else
+ timer_delete_sync(&ktimer);
+
+ return 0;
+}
+
+/*
+ * The PPS info struct
+ */
+
+static const struct pps_gen_source_info pps_gen_dummy_info = {
+ .use_system_clock = true,
+ .get_time = pps_gen_dummy_get_time,
+ .enable = pps_gen_dummy_enable,
+};
+
+/*
+ * Module staff
+ */
+
+static void __exit pps_gen_dummy_exit(void)
+{
+ timer_delete_sync(&ktimer);
+ pps_gen_unregister_source(pps_gen);
+}
+
+static int __init pps_gen_dummy_init(void)
+{
+ pps_gen = pps_gen_register_source(&pps_gen_dummy_info);
+ if (IS_ERR(pps_gen))
+ return PTR_ERR(pps_gen);
+
+ timer_setup(&ktimer, pps_gen_ktimer_event, 0);
+
+ return 0;
+}
+
+module_init(pps_gen_dummy_init);
+module_exit(pps_gen_dummy_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@enneenne.com>");
+MODULE_DESCRIPTION("LinuxPPS dummy generator");
+MODULE_LICENSE("GPL");
diff --git a/drivers/pps/generators/pps_gen.c b/drivers/pps/generators/pps_gen.c
new file mode 100644
index 000000000..5e207c75e
--- /dev/null
+++ b/drivers/pps/generators/pps_gen.c
@@ -0,0 +1,346 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PPS generators core file
+ *
+ * Copyright (C) 2024 Rodolfo Giometti <giometti@enneenne.com>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/sched.h>
+#include <linux/time.h>
+#include <linux/timex.h>
+#include <linux/uaccess.h>
+#include <linux/idr.h>
+#include <linux/cdev.h>
+#include <linux/poll.h>
+#include <linux/fs.h>
+#include <linux/pps_gen_kernel.h>
+#include <linux/slab.h>
+
+/*
+ * Local variables
+ */
+
+static dev_t pps_gen_devt;
+static const struct class pps_gen_class = {
+ .name = "pps-gen",
+ .dev_groups = pps_gen_groups
+};
+
+static DEFINE_IDA(pps_gen_ida);
+
+/*
+ * Char device methods
+ */
+
+static __poll_t pps_gen_cdev_poll(struct file *file, poll_table *wait)
+{
+ struct pps_gen_device *pps_gen = file->private_data;
+
+ poll_wait(file, &pps_gen->queue, wait);
+ return EPOLLIN | EPOLLRDNORM;
+}
+
+static int pps_gen_cdev_fasync(int fd, struct file *file, int on)
+{
+ struct pps_gen_device *pps_gen = file->private_data;
+
+ return fasync_helper(fd, file, on, &pps_gen->async_queue);
+}
+
+static long pps_gen_cdev_ioctl(struct file *file,
+ unsigned int cmd, unsigned long arg)
+{
+ struct pps_gen_device *pps_gen = file->private_data;
+ void __user *uarg = (void __user *) arg;
+ unsigned int __user *uiuarg = (unsigned int __user *) arg;
+ unsigned int status;
+ int ret;
+
+ switch (cmd) {
+ case PPS_GEN_SETENABLE:
+ dev_dbg(pps_gen->dev, "PPS_GEN_SETENABLE\n");
+
+ ret = get_user(status, uiuarg);
+ if (ret)
+ return -EFAULT;
+
+ ret = pps_gen->info->enable(pps_gen, status);
+ if (ret)
+ return ret;
+ pps_gen->enabled = status;
+
+ break;
+
+ case PPS_GEN_USESYSTEMCLOCK:
+ dev_dbg(pps_gen->dev, "PPS_GEN_USESYSTEMCLOCK\n");
+
+ ret = put_user(pps_gen->info->use_system_clock, uiuarg);
+ if (ret)
+ return -EFAULT;
+
+ break;
+
+ case PPS_GEN_FETCHEVENT: {
+ struct pps_gen_event info;
+ unsigned int ev = pps_gen->last_ev;
+
+ dev_dbg(pps_gen->dev, "PPS_GEN_FETCHEVENT\n");
+
+ ret = wait_event_interruptible(pps_gen->queue,
+ ev != pps_gen->last_ev);
+ if (ret == -ERESTARTSYS) {
+ dev_dbg(pps_gen->dev, "pending signal caught\n");
+ return -EINTR;
+ }
+
+ spin_lock_irq(&pps_gen->lock);
+ info.sequence = pps_gen->sequence;
+ info.event = pps_gen->event;
+ spin_unlock_irq(&pps_gen->lock);
+
+ ret = copy_to_user(uarg, &info, sizeof(struct pps_gen_event));
+ if (ret)
+ return -EFAULT;
+
+ break;
+ }
+ default:
+ return -ENOTTY;
+ }
+
+ return 0;
+}
+
+static int pps_gen_cdev_open(struct inode *inode, struct file *file)
+{
+ struct pps_gen_device *pps_gen = container_of(inode->i_cdev,
+ struct pps_gen_device, cdev);
+
+ get_device(pps_gen->dev);
+ file->private_data = pps_gen;
+ return 0;
+}
+
+static int pps_gen_cdev_release(struct inode *inode, struct file *file)
+{
+ struct pps_gen_device *pps_gen = file->private_data;
+
+ put_device(pps_gen->dev);
+ return 0;
+}
+
+/*
+ * Char device stuff
+ */
+
+static const struct file_operations pps_gen_cdev_fops = {
+ .owner = THIS_MODULE,
+ .poll = pps_gen_cdev_poll,
+ .fasync = pps_gen_cdev_fasync,
+ .unlocked_ioctl = pps_gen_cdev_ioctl,
+ .open = pps_gen_cdev_open,
+ .release = pps_gen_cdev_release,
+};
+
+static void pps_gen_device_destruct(struct device *dev)
+{
+ struct pps_gen_device *pps_gen = dev_get_drvdata(dev);
+
+ cdev_del(&pps_gen->cdev);
+
+ pr_debug("deallocating pps-gen%d\n", pps_gen->id);
+ ida_free(&pps_gen_ida, pps_gen->id);
+
+ kfree(dev);
+ kfree(pps_gen);
+}
+
+static int pps_gen_register_cdev(struct pps_gen_device *pps_gen)
+{
+ int err;
+ dev_t devt;
+
+ err = ida_alloc_max(&pps_gen_ida, PPS_GEN_MAX_SOURCES - 1, GFP_KERNEL);
+ if (err < 0) {
+ if (err == -ENOSPC) {
+ pr_err("too many PPS sources in the system\n");
+ err = -EBUSY;
+ }
+ return err;
+ }
+ pps_gen->id = err;
+
+ devt = MKDEV(MAJOR(pps_gen_devt), pps_gen->id);
+
+ cdev_init(&pps_gen->cdev, &pps_gen_cdev_fops);
+ pps_gen->cdev.owner = pps_gen->info->owner;
+
+ err = cdev_add(&pps_gen->cdev, devt, 1);
+ if (err) {
+ pr_err("failed to add char device %d:%d\n",
+ MAJOR(pps_gen_devt), pps_gen->id);
+ goto free_ida;
+ }
+ pps_gen->dev = device_create(&pps_gen_class, pps_gen->info->parent, devt,
+ pps_gen, "pps-gen%d", pps_gen->id);
+ if (IS_ERR(pps_gen->dev)) {
+ err = PTR_ERR(pps_gen->dev);
+ goto del_cdev;
+ }
+ pps_gen->dev->release = pps_gen_device_destruct;
+ dev_set_drvdata(pps_gen->dev, pps_gen);
+
+ pr_debug("generator got cdev (%d:%d)\n",
+ MAJOR(pps_gen_devt), pps_gen->id);
+
+ return 0;
+
+del_cdev:
+ cdev_del(&pps_gen->cdev);
+free_ida:
+ ida_free(&pps_gen_ida, pps_gen->id);
+ return err;
+}
+
+static void pps_gen_unregister_cdev(struct pps_gen_device *pps_gen)
+{
+ pr_debug("unregistering pps-gen%d\n", pps_gen->id);
+ device_destroy(&pps_gen_class, pps_gen->dev->devt);
+}
+
+/*
+ * Exported functions
+ */
+
+/**
+ * pps_gen_register_source() - add a PPS generator in the system
+ * @info: the PPS generator info struct
+ *
+ * This function is used to register a new PPS generator in the system.
+ * When it returns successfully the new generator is up and running, and
+ * it can be managed by the userspace.
+ *
+ * Return: the PPS generator device in case of success, and ERR_PTR(errno)
+ * otherwise.
+ */
+struct pps_gen_device *pps_gen_register_source(const struct pps_gen_source_info *info)
+{
+ struct pps_gen_device *pps_gen;
+ int err;
+
+ pps_gen = kzalloc_obj(struct pps_gen_device);
+ if (pps_gen == NULL) {
+ err = -ENOMEM;
+ goto pps_gen_register_source_exit;
+ }
+ pps_gen->info = info;
+ pps_gen->enabled = false;
+
+ init_waitqueue_head(&pps_gen->queue);
+ spin_lock_init(&pps_gen->lock);
+
+ /* Create the char device */
+ err = pps_gen_register_cdev(pps_gen);
+ if (err < 0) {
+ pr_err(" unable to create char device\n");
+ goto kfree_pps_gen;
+ }
+
+ return pps_gen;
+
+kfree_pps_gen:
+ kfree(pps_gen);
+
+pps_gen_register_source_exit:
+ pr_err("unable to register generator\n");
+
+ return ERR_PTR(err);
+}
+EXPORT_SYMBOL(pps_gen_register_source);
+
+/**
+ * pps_gen_unregister_source() - remove a PPS generator from the system
+ * @pps_gen: the PPS generator device to be removed
+ *
+ * This function is used to deregister a PPS generator from the system. When
+ * called, it disables the generator so no pulses are generated anymore.
+ */
+void pps_gen_unregister_source(struct pps_gen_device *pps_gen)
+{
+ pps_gen_unregister_cdev(pps_gen);
+}
+EXPORT_SYMBOL(pps_gen_unregister_source);
+
+/* pps_gen_event - register a PPS generator event into the system
+ * @pps: the PPS generator device
+ * @event: the event type
+ * @data: userdef pointer
+ *
+ * This function is used by each PPS generator in order to register a new
+ * PPS event into the system (it's usually called inside an IRQ handler).
+ */
+void pps_gen_event(struct pps_gen_device *pps_gen,
+ unsigned int event, void *data)
+{
+ unsigned long flags;
+
+ dev_dbg(pps_gen->dev, "PPS generator event %u\n", event);
+
+ spin_lock_irqsave(&pps_gen->lock, flags);
+
+ pps_gen->event = event;
+ pps_gen->sequence++;
+
+ pps_gen->last_ev++;
+ wake_up_interruptible_all(&pps_gen->queue);
+ kill_fasync(&pps_gen->async_queue, SIGIO, POLL_IN);
+
+ spin_unlock_irqrestore(&pps_gen->lock, flags);
+}
+EXPORT_SYMBOL(pps_gen_event);
+
+/*
+ * Module stuff
+ */
+
+static void __exit pps_gen_exit(void)
+{
+ class_unregister(&pps_gen_class);
+ unregister_chrdev_region(pps_gen_devt, PPS_GEN_MAX_SOURCES);
+}
+
+static int __init pps_gen_init(void)
+{
+ int err;
+
+ err = class_register(&pps_gen_class);
+ if (err) {
+ pr_err("failed to register class\n");
+ return err;
+ }
+
+ err = alloc_chrdev_region(&pps_gen_devt, 0,
+ PPS_GEN_MAX_SOURCES, "pps-gen");
+ if (err < 0) {
+ pr_err("failed to allocate char device region\n");
+ goto remove_class;
+ }
+
+ return 0;
+
+remove_class:
+ class_unregister(&pps_gen_class);
+ return err;
+}
+
+subsys_initcall(pps_gen_init);
+module_exit(pps_gen_exit);
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@enneenne.com>");
+MODULE_DESCRIPTION("LinuxPPS generators support");
+MODULE_LICENSE("GPL");
diff --git a/drivers/pps/generators/pps_gen_tio.c b/drivers/pps/generators/pps_gen_tio.c
new file mode 100644
index 000000000..5088aaf1a
--- /dev/null
+++ b/drivers/pps/generators/pps_gen_tio.c
@@ -0,0 +1,267 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel PPS signal Generator Driver
+ *
+ * Copyright (C) 2024 Intel Corporation
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/cleanup.h>
+#include <linux/container_of.h>
+#include <linux/device.h>
+#include <linux/hrtimer.h>
+#include <linux/io-64-nonatomic-hi-lo.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pps_gen_kernel.h>
+#include <linux/timekeeping.h>
+#include <linux/types.h>
+
+#include <asm/cpu_device_id.h>
+
+#define TIOCTL 0x00
+#define TIOCOMPV 0x10
+#define TIOEC 0x30
+
+/* Control Register */
+#define TIOCTL_EN BIT(0)
+#define TIOCTL_DIR BIT(1)
+#define TIOCTL_EP GENMASK(3, 2)
+#define TIOCTL_EP_RISING_EDGE FIELD_PREP(TIOCTL_EP, 0)
+#define TIOCTL_EP_FALLING_EDGE FIELD_PREP(TIOCTL_EP, 1)
+#define TIOCTL_EP_TOGGLE_EDGE FIELD_PREP(TIOCTL_EP, 2)
+
+/* Safety time to set hrtimer early */
+#define SAFE_TIME_NS (10 * NSEC_PER_MSEC)
+
+#define MAGIC_CONST (NSEC_PER_SEC - SAFE_TIME_NS)
+#define ART_HW_DELAY_CYCLES 2
+
+struct pps_tio {
+ struct pps_gen_source_info gen_info;
+ struct pps_gen_device *pps_gen;
+ struct hrtimer timer;
+ void __iomem *base;
+ u32 prev_count;
+ spinlock_t lock;
+ struct device *dev;
+};
+
+static inline u32 pps_tio_read(u32 offset, struct pps_tio *tio)
+{
+ return readl(tio->base + offset);
+}
+
+static inline void pps_ctl_write(u32 value, struct pps_tio *tio)
+{
+ writel(value, tio->base + TIOCTL);
+}
+
+/*
+ * For COMPV register, It's safer to write
+ * higher 32-bit followed by lower 32-bit
+ */
+static inline void pps_compv_write(u64 value, struct pps_tio *tio)
+{
+ hi_lo_writeq(value, tio->base + TIOCOMPV);
+}
+
+static inline ktime_t first_event(struct pps_tio *tio)
+{
+ return ktime_set(ktime_get_real_seconds() + 1, MAGIC_CONST);
+}
+
+static u32 pps_tio_disable(struct pps_tio *tio)
+{
+ u32 ctrl;
+
+ ctrl = pps_tio_read(TIOCTL, tio);
+ pps_compv_write(0, tio);
+
+ ctrl &= ~TIOCTL_EN;
+ pps_ctl_write(ctrl, tio);
+ tio->pps_gen->enabled = false;
+ tio->prev_count = 0;
+ return ctrl;
+}
+
+static void pps_tio_enable(struct pps_tio *tio)
+{
+ u32 ctrl;
+
+ ctrl = pps_tio_read(TIOCTL, tio);
+ ctrl |= TIOCTL_EN;
+ pps_ctl_write(ctrl, tio);
+ tio->pps_gen->enabled = true;
+}
+
+static void pps_tio_direction_output(struct pps_tio *tio)
+{
+ u32 ctrl;
+
+ ctrl = pps_tio_disable(tio);
+
+ /*
+ * We enable the device, be sure that the
+ * 'compare' value is invalid
+ */
+ pps_compv_write(0, tio);
+
+ ctrl &= ~(TIOCTL_DIR | TIOCTL_EP);
+ ctrl |= TIOCTL_EP_TOGGLE_EDGE;
+ pps_ctl_write(ctrl, tio);
+ pps_tio_enable(tio);
+}
+
+static bool pps_generate_next_pulse(ktime_t expires, struct pps_tio *tio)
+{
+ u64 art;
+
+ if (!ktime_real_to_base_clock(expires, CSID_X86_ART, &art)) {
+ pps_tio_disable(tio);
+ return false;
+ }
+
+ pps_compv_write(art - ART_HW_DELAY_CYCLES, tio);
+ return true;
+}
+
+static enum hrtimer_restart hrtimer_callback(struct hrtimer *timer)
+{
+ ktime_t expires, now;
+ u32 event_count;
+ struct pps_tio *tio = container_of(timer, struct pps_tio, timer);
+
+ guard(spinlock)(&tio->lock);
+
+ /*
+ * Check if any event is missed.
+ * If an event is missed, TIO will be disabled.
+ */
+ event_count = pps_tio_read(TIOEC, tio);
+ if (tio->prev_count && tio->prev_count == event_count)
+ goto err;
+ tio->prev_count = event_count;
+
+ expires = hrtimer_get_expires(timer);
+
+ now = ktime_get_real();
+ if (now - expires >= SAFE_TIME_NS)
+ goto err;
+
+ tio->pps_gen->enabled = pps_generate_next_pulse(expires + SAFE_TIME_NS, tio);
+ if (!tio->pps_gen->enabled)
+ return HRTIMER_NORESTART;
+
+ hrtimer_forward(timer, now, NSEC_PER_SEC / 2);
+ return HRTIMER_RESTART;
+
+err:
+ dev_err(tio->dev, "Event missed, Disabling Timed I/O");
+ pps_tio_disable(tio);
+ pps_gen_event(tio->pps_gen, PPS_GEN_EVENT_MISSEDPULSE, NULL);
+ return HRTIMER_NORESTART;
+}
+
+static int pps_tio_gen_enable(struct pps_gen_device *pps_gen, bool enable)
+{
+ struct pps_tio *tio = container_of(pps_gen->info, struct pps_tio, gen_info);
+
+ if (!timekeeping_clocksource_has_base(CSID_X86_ART)) {
+ dev_err_once(tio->dev, "PPS cannot be used as clock is not related to ART");
+ return -ENODEV;
+ }
+
+ guard(spinlock_irqsave)(&tio->lock);
+ if (enable && !pps_gen->enabled) {
+ pps_tio_direction_output(tio);
+ hrtimer_start(&tio->timer, first_event(tio), HRTIMER_MODE_ABS);
+ } else if (!enable && pps_gen->enabled) {
+ hrtimer_cancel(&tio->timer);
+ pps_tio_disable(tio);
+ }
+
+ return 0;
+}
+
+static int pps_tio_get_time(struct pps_gen_device *pps_gen,
+ struct timespec64 *time)
+{
+ ktime_get_real_ts64(time);
+ return 0;
+}
+
+static int pps_gen_tio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct pps_tio *tio;
+
+ if (!(cpu_feature_enabled(X86_FEATURE_TSC_KNOWN_FREQ) &&
+ cpu_feature_enabled(X86_FEATURE_ART))) {
+ dev_warn(dev, "TSC/ART is not enabled");
+ return -ENODEV;
+ }
+
+ tio = devm_kzalloc(dev, sizeof(*tio), GFP_KERNEL);
+ if (!tio)
+ return -ENOMEM;
+
+ tio->gen_info.use_system_clock = true;
+ tio->gen_info.enable = pps_tio_gen_enable;
+ tio->gen_info.get_time = pps_tio_get_time;
+ tio->gen_info.owner = THIS_MODULE;
+
+ tio->pps_gen = pps_gen_register_source(&tio->gen_info);
+ if (IS_ERR(tio->pps_gen))
+ return PTR_ERR(tio->pps_gen);
+
+ tio->dev = dev;
+ tio->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(tio->base))
+ return PTR_ERR(tio->base);
+
+ pps_tio_disable(tio);
+ hrtimer_setup(&tio->timer, hrtimer_callback, CLOCK_REALTIME,
+ HRTIMER_MODE_ABS);
+ spin_lock_init(&tio->lock);
+ platform_set_drvdata(pdev, tio);
+
+ return 0;
+}
+
+static void pps_gen_tio_remove(struct platform_device *pdev)
+{
+ struct pps_tio *tio = platform_get_drvdata(pdev);
+
+ hrtimer_cancel(&tio->timer);
+ pps_tio_disable(tio);
+ pps_gen_unregister_source(tio->pps_gen);
+}
+
+static const struct acpi_device_id intel_pmc_tio_acpi_match[] = {
+ { "INTC1021" },
+ { "INTC1022" },
+ { "INTC1023" },
+ { "INTC1024" },
+ {}
+};
+MODULE_DEVICE_TABLE(acpi, intel_pmc_tio_acpi_match);
+
+static struct platform_driver pps_gen_tio_driver = {
+ .probe = pps_gen_tio_probe,
+ .remove = pps_gen_tio_remove,
+ .driver = {
+ .name = "intel-pps-gen-tio",
+ .acpi_match_table = intel_pmc_tio_acpi_match,
+ },
+};
+module_platform_driver(pps_gen_tio_driver);
+
+MODULE_AUTHOR("Christopher Hall <christopher.s.hall@intel.com>");
+MODULE_AUTHOR("Lakshmi Sowjanya D <lakshmi.sowjanya.d@intel.com>");
+MODULE_AUTHOR("Pandith N <pandith.n@intel.com>");
+MODULE_AUTHOR("Thejesh Reddy T R <thejesh.reddy.t.r@intel.com>");
+MODULE_AUTHOR("Subramanian Mohan <subramanian.mohan@intel.com>");
+MODULE_DESCRIPTION("Intel PMC Time-Aware IO Generator Driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/pps/generators/sysfs.c b/drivers/pps/generators/sysfs.c
new file mode 100644
index 000000000..6d6bc0006
--- /dev/null
+++ b/drivers/pps/generators/sysfs.c
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * PPS generators sysfs support
+ *
+ * Copyright (C) 2024 Rodolfo Giometti <giometti@enneenne.com>
+ */
+
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/pps_gen_kernel.h>
+
+/*
+ * Attribute functions
+ */
+
+static ssize_t system_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct pps_gen_device *pps_gen = dev_get_drvdata(dev);
+
+ return sysfs_emit(buf, "%d\n", pps_gen->info->use_system_clock);
+}
+static DEVICE_ATTR_RO(system);
+
+static ssize_t time_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct pps_gen_device *pps_gen = dev_get_drvdata(dev);
+ struct timespec64 time;
+ int ret;
+
+ ret = pps_gen->info->get_time(pps_gen, &time);
+ if (ret)
+ return ret;
+
+ return sysfs_emit(buf, "%llu %09lu\n", time.tv_sec, time.tv_nsec);
+}
+static DEVICE_ATTR_RO(time);
+
+static ssize_t enable_store(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct pps_gen_device *pps_gen = dev_get_drvdata(dev);
+ bool status;
+ int ret;
+
+ ret = kstrtobool(buf, &status);
+ if (ret)
+ return ret;
+
+ ret = pps_gen->info->enable(pps_gen, status);
+ if (ret)
+ return ret;
+ pps_gen->enabled = status;
+
+ return count;
+}
+static DEVICE_ATTR_WO(enable);
+
+static struct attribute *pps_gen_attrs[] = {
+ &dev_attr_enable.attr,
+ &dev_attr_time.attr,
+ &dev_attr_system.attr,
+ NULL,
+};
+
+static const struct attribute_group pps_gen_group = {
+ .attrs = pps_gen_attrs,
+};
+
+const struct attribute_group *pps_gen_groups[] = {
+ &pps_gen_group,
+ NULL,
+};