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
  ...

1 files changed, 735 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-optee.c b/drivers/rtc/rtc-optee.c
new file mode 100644
index 000000000..6c908c0d8
--- /dev/null
+++ b/drivers/rtc/rtc-optee.c
@@ -0,0 +1,735 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2022 Microchip.
+ */
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/tee_drv.h>
+
+#define RTC_INFO_VERSION			0x1
+
+#define TA_RTC_FEATURE_CORRECTION		BIT(0)
+#define TA_RTC_FEATURE_ALARM			BIT(1)
+#define TA_RTC_FEATURE_WAKEUP_ALARM		BIT(2)
+
+enum rtc_optee_pta_cmd {
+	/*  PTA_CMD_RTC_GET_INFO - Get RTC information
+	 *
+	 * [out]        memref[0]  RTC buffer memory reference containing a struct pta_rtc_info
+	 */
+	PTA_CMD_RTC_GET_INF = 0x0,
+
+	/*
+	 * PTA_CMD_RTC_GET_TIME - Get time from RTC
+	 *
+	 * [out]    memref[0]  RTC buffer memory reference containing a struct pta_rtc_time
+	 */
+	PTA_CMD_RTC_GET_TIME = 0x1,
+
+	/*
+	 * PTA_CMD_RTC_SET_TIME - Set time from RTC
+	 *
+	 * [in]     memref[0]  RTC buffer memory reference containing a struct pta_rtc_time to be
+	 *                     used as RTC time
+	 */
+	PTA_CMD_RTC_SET_TIME = 0x2,
+
+	/*
+	 * PTA_CMD_RTC_GET_OFFSET - Get RTC offset
+	 *
+	 * [out]    value[0].a  RTC offset (signed 32bit value)
+	 */
+	PTA_CMD_RTC_GET_OFFSET = 0x3,
+
+	/*
+	 * PTA_CMD_RTC_SET_OFFSET - Set RTC offset
+	 *
+	 * [in]     value[0].a  RTC offset to be set (signed 32bit value)
+	 */
+	PTA_CMD_RTC_SET_OFFSET = 0x4,
+
+	/*
+	 * PTA_CMD_RTC_READ_ALARM - Read RTC alarm
+	 *
+	 * [out]     memref[0]  RTC buffer memory reference containing a struct pta_rtc_alarm
+	 */
+	PTA_CMD_RTC_READ_ALARM = 0x5,
+
+	/*
+	 * PTA_CMD_RTC_SET_ALARM - Set RTC alarm
+	 *
+	 * [in]     memref[0]  RTC buffer memory reference containing a struct pta_rtc_alarm to be
+	 *                     used as RTC alarm
+	 */
+	PTA_CMD_RTC_SET_ALARM = 0x6,
+
+	/*
+	 * PTA_CMD_RTC_ENABLE_ALARM - Enable Alarm
+	 *
+	 * [in]     value[0].a  RTC IRQ flag (uint32_t), 0 to disable the alarm, 1 to enable
+	 */
+	PTA_CMD_RTC_ENABLE_ALARM = 0x7,
+
+	/*
+	 * PTA_CMD_RTC_WAIT_ALARM - Get alarm event
+	 *
+	 * [out]     value[0].a  RTC wait alarm return status (uint32_t):
+	 *                       - 0: No alarm event
+	 *                       - 1: Alarm event occurred
+	 *                       - 2: Alarm event canceled
+	 */
+	PTA_CMD_RTC_WAIT_ALARM = 0x8,
+
+	/*
+	 * PTA_CMD_RTC_CANCEL_WAIT - Cancel wait for alarm event
+	 */
+	PTA_CMD_RTC_CANCEL_WAIT = 0x9,
+
+	/*
+	 * PTA_CMD_RTC_SET_WAKE_ALARM_STATUS - Set RTC wake alarm status flag
+	 *
+	 * [in]     value[0].a RTC IRQ wake alarm flag (uint32_t), 0 to disable the wake up
+	 *                     capability, 1 to enable.
+	 */
+	PTA_CMD_RTC_SET_WAKE_ALARM_STATUS = 0xA,
+};
+
+enum rtc_wait_alarm_status {
+	WAIT_ALARM_RESET = 0x0,
+	WAIT_ALARM_ALARM_OCCURRED = 0x1,
+	WAIT_ALARM_CANCELED = 0x2,
+};
+
+struct optee_rtc_time {
+	u32 tm_sec;
+	u32 tm_min;
+	u32 tm_hour;
+	u32 tm_mday;
+	u32 tm_mon;
+	u32 tm_year;
+	u32 tm_wday;
+};
+
+struct optee_rtc_alarm {
+	u8 enabled;
+	u8 pending;
+	struct optee_rtc_time time;
+};
+
+struct optee_rtc_info {
+	u64 version;
+	u64 features;
+	struct optee_rtc_time range_min;
+	struct optee_rtc_time range_max;
+};
+
+/**
+ * struct optee_rtc - OP-TEE RTC private data
+ * @dev:		OP-TEE based RTC device.
+ * @ctx:		OP-TEE context handler.
+ * @session_id:		RTC TA session identifier.
+ * @session2_id:	RTC wait alarm session identifier.
+ * @shm:		Memory pool shared with RTC device.
+ * @features:		Bitfield of RTC features
+ * @alarm_task:		RTC wait alamr task.
+ * @rtc:		RTC device.
+ */
+struct optee_rtc {
+	struct device *dev;
+	struct tee_context *ctx;
+	u32 session_id;
+	u32 session2_id;
+	struct tee_shm *shm;
+	u64 features;
+	struct task_struct *alarm_task;
+	struct rtc_device *rtc;
+};
+
+static int optee_rtc_readtime(struct device *dev, struct rtc_time *tm)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct optee_rtc_time *optee_tm;
+	struct tee_param param[4] = {0};
+	int ret;
+
+	inv_arg.func = PTA_CMD_RTC_GET_TIME;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 4;
+
+	/* Fill invoke cmd params */
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[0].u.memref.shm = priv->shm;
+	param[0].u.memref.size = sizeof(struct optee_rtc_time);
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	optee_tm = tee_shm_get_va(priv->shm, 0);
+	if (IS_ERR(optee_tm))
+		return PTR_ERR(optee_tm);
+
+	if (param[0].u.memref.size != sizeof(*optee_tm))
+		return -EPROTO;
+
+	tm->tm_sec = optee_tm->tm_sec;
+	tm->tm_min = optee_tm->tm_min;
+	tm->tm_hour = optee_tm->tm_hour;
+	tm->tm_mday = optee_tm->tm_mday;
+	tm->tm_mon = optee_tm->tm_mon;
+	tm->tm_year = optee_tm->tm_year - 1900;
+	tm->tm_wday = optee_tm->tm_wday;
+	tm->tm_yday = rtc_year_days(tm->tm_mday, tm->tm_mon, tm->tm_year);
+
+	return 0;
+}
+
+static int optee_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[4] = {0};
+	struct optee_rtc_time *optee_tm;
+	int ret;
+
+	inv_arg.func = PTA_CMD_RTC_SET_TIME;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+	param[0].u.memref.shm = priv->shm;
+	param[0].u.memref.size = sizeof(struct optee_rtc_time);
+
+	optee_tm = tee_shm_get_va(priv->shm, 0);
+	if (IS_ERR(optee_tm))
+		return PTR_ERR(optee_tm);
+
+	optee_tm->tm_min = tm->tm_min;
+	optee_tm->tm_sec = tm->tm_sec;
+	optee_tm->tm_hour = tm->tm_hour;
+	optee_tm->tm_mday = tm->tm_mday;
+	optee_tm->tm_mon = tm->tm_mon;
+	optee_tm->tm_year = tm->tm_year + 1900;
+	optee_tm->tm_wday = tm->tm_wday;
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	return 0;
+}
+
+static int optee_rtc_readoffset(struct device *dev, long *offset)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[4] = {0};
+	int ret;
+
+	if (!(priv->features & TA_RTC_FEATURE_CORRECTION))
+		return -EOPNOTSUPP;
+
+	inv_arg.func = PTA_CMD_RTC_GET_OFFSET;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	*offset = param[0].u.value.a;
+
+	return 0;
+}
+
+static int optee_rtc_setoffset(struct device *dev, long offset)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[4] = {0};
+	int ret;
+
+	if (!(priv->features & TA_RTC_FEATURE_CORRECTION))
+		return -EOPNOTSUPP;
+
+	inv_arg.func = PTA_CMD_RTC_SET_OFFSET;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+	param[0].u.value.a = offset;
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	return 0;
+}
+
+static int optee_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct optee_rtc_alarm *optee_alarm;
+	struct tee_param param[1] = {0};
+	int ret;
+
+	if (!(priv->features & TA_RTC_FEATURE_ALARM))
+		return -EOPNOTSUPP;
+
+	inv_arg.func = PTA_CMD_RTC_READ_ALARM;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 1;
+
+	/* Fill invoke cmd params */
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[0].u.memref.shm = priv->shm;
+	param[0].u.memref.size = sizeof(struct optee_rtc_alarm);
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	optee_alarm = tee_shm_get_va(priv->shm, 0);
+	if (IS_ERR(optee_alarm))
+		return PTR_ERR(optee_alarm);
+
+	if (param[0].u.memref.size != sizeof(*optee_alarm))
+		return -EPROTO;
+
+	alarm->enabled = optee_alarm->enabled;
+	alarm->pending = optee_alarm->pending;
+	alarm->time.tm_sec = optee_alarm->time.tm_sec;
+	alarm->time.tm_min = optee_alarm->time.tm_min;
+	alarm->time.tm_hour = optee_alarm->time.tm_hour;
+	alarm->time.tm_mday = optee_alarm->time.tm_mday;
+	alarm->time.tm_mon = optee_alarm->time.tm_mon;
+	alarm->time.tm_year = optee_alarm->time.tm_year - 1900;
+	alarm->time.tm_wday = optee_alarm->time.tm_wday;
+	alarm->time.tm_yday = rtc_year_days(alarm->time.tm_mday,
+					    alarm->time.tm_mon,
+					    alarm->time.tm_year);
+
+	return 0;
+}
+
+static int optee_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct optee_rtc_alarm *optee_alarm;
+	struct tee_param param[1] = {0};
+	int ret;
+
+	if (!(priv->features & TA_RTC_FEATURE_ALARM))
+		return -EOPNOTSUPP;
+
+	inv_arg.func = PTA_CMD_RTC_SET_ALARM;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 1;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+	param[0].u.memref.shm = priv->shm;
+	param[0].u.memref.size = sizeof(struct optee_rtc_alarm);
+
+	optee_alarm = tee_shm_get_va(priv->shm, 0);
+	if (IS_ERR(optee_alarm))
+		return PTR_ERR(optee_alarm);
+
+	optee_alarm->enabled = alarm->enabled;
+	optee_alarm->pending = alarm->pending;
+	optee_alarm->time.tm_sec = alarm->time.tm_sec;
+	optee_alarm->time.tm_min = alarm->time.tm_min;
+	optee_alarm->time.tm_hour = alarm->time.tm_hour;
+	optee_alarm->time.tm_mday = alarm->time.tm_mday;
+	optee_alarm->time.tm_mon = alarm->time.tm_mon;
+	optee_alarm->time.tm_year = alarm->time.tm_year + 1900;
+	optee_alarm->time.tm_wday = alarm->time.tm_wday;
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	return 0;
+}
+
+static int optee_rtc_enable_alarm(struct device *dev, unsigned int enabled)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[1] = {0};
+	int ret;
+
+	if (!(priv->features & TA_RTC_FEATURE_ALARM))
+		return -EOPNOTSUPP;
+
+	inv_arg.func = PTA_CMD_RTC_ENABLE_ALARM;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 1;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+	param[0].u.value.a = (bool)enabled;
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	return 0;
+}
+
+static const struct rtc_class_ops optee_rtc_ops = {
+	.read_time		= optee_rtc_readtime,
+	.set_time		= optee_rtc_settime,
+	.set_offset		= optee_rtc_setoffset,
+	.read_offset		= optee_rtc_readoffset,
+	.read_alarm		= optee_rtc_read_alarm,
+	.set_alarm		= optee_rtc_set_alarm,
+	.alarm_irq_enable	= optee_rtc_enable_alarm,
+};
+
+static int optee_rtc_wait_alarm(struct device *dev, int *return_status)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[1] = {0};
+	int ret;
+
+	if (!(priv->features & TA_RTC_FEATURE_ALARM))
+		return -EOPNOTSUPP;
+
+	inv_arg.func = PTA_CMD_RTC_WAIT_ALARM;
+	inv_arg.session = priv->session2_id;
+	inv_arg.num_params = 1;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT;
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	*return_status = param[0].u.value.a;
+
+	return 0;
+}
+
+static int optee_rtc_cancel_wait_alarm(struct device *dev)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[1] = {0};
+	int ret;
+
+	if (!(priv->features & TA_RTC_FEATURE_ALARM))
+		return -EOPNOTSUPP;
+
+	inv_arg.func = PTA_CMD_RTC_CANCEL_WAIT;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 0;
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	return 0;
+}
+
+static int optee_rtc_set_alarm_wake_status(struct device *dev, bool status)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[1] = {0};
+	int ret;
+
+	if (!(priv->features & TA_RTC_FEATURE_ALARM))
+		return -EOPNOTSUPP;
+
+	inv_arg.func = PTA_CMD_RTC_SET_WAKE_ALARM_STATUS;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 1;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
+	param[0].u.value.a = status;
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	return 0;
+}
+
+static int optee_rtc_handle_alarm_event(void *data)
+{
+	struct optee_rtc *priv = (struct optee_rtc *)data;
+	int wait_alarm_return_status = 0;
+	int ret;
+
+	while (!kthread_should_stop()) {
+		ret = optee_rtc_wait_alarm(priv->dev, &wait_alarm_return_status);
+		if (ret) {
+			dev_err(priv->dev, "Failed to wait for alarm: %d\n", ret);
+			return ret;
+		}
+		switch (wait_alarm_return_status) {
+		case WAIT_ALARM_ALARM_OCCURRED:
+			dev_dbg(priv->dev, "Alarm occurred\n");
+			rtc_update_irq(priv->rtc, 1, RTC_IRQF | RTC_AF);
+			break;
+		case WAIT_ALARM_CANCELED:
+			dev_dbg(priv->dev, "Alarm canceled\n");
+			break;
+		default:
+			dev_warn(priv->dev, "Unknown return status: %d\n",
+				 wait_alarm_return_status);
+			break;
+		}
+	}
+
+	return 0;
+}
+
+static int optee_rtc_read_info(struct device *dev, struct rtc_device *rtc,
+			       u64 *features)
+{
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+	struct tee_ioctl_invoke_arg inv_arg = {0};
+	struct tee_param param[4] = {0};
+	struct optee_rtc_info *info;
+	struct optee_rtc_time *tm;
+	int ret;
+
+	inv_arg.func = PTA_CMD_RTC_GET_INF;
+	inv_arg.session = priv->session_id;
+	inv_arg.num_params = 4;
+
+	param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
+	param[0].u.memref.shm = priv->shm;
+	param[0].u.memref.size = sizeof(*info);
+
+	ret = tee_client_invoke_func(priv->ctx, &inv_arg, param);
+	if (ret < 0 || inv_arg.ret != 0)
+		return ret ? ret : -EPROTO;
+
+	info = tee_shm_get_va(priv->shm, 0);
+	if (IS_ERR(info))
+		return PTR_ERR(info);
+
+	if (param[0].u.memref.size != sizeof(*info))
+		return -EPROTO;
+
+	if (info->version != RTC_INFO_VERSION)
+		return -EPROTO;
+
+	*features = info->features;
+
+	tm = &info->range_min;
+	rtc->range_min = mktime64(tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min,
+				  tm->tm_sec);
+	tm = &info->range_max;
+	rtc->range_max = mktime64(tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min,
+				  tm->tm_sec);
+
+	return 0;
+}
+
+static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
+{
+	return (ver->impl_id == TEE_IMPL_ID_OPTEE);
+}
+
+static int optee_rtc_probe(struct tee_client_device *rtc_device)
+{
+	struct device *dev = &rtc_device->dev;
+	struct tee_ioctl_open_session_arg sess2_arg = {0};
+	struct tee_ioctl_open_session_arg sess_arg = {0};
+	struct optee_rtc *priv;
+	struct rtc_device *rtc;
+	struct tee_shm *shm;
+	int ret, err;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	rtc = devm_rtc_allocate_device(dev);
+	if (IS_ERR(rtc))
+		return PTR_ERR(rtc);
+
+	priv->rtc = rtc;
+
+	/* Open context with TEE driver */
+	priv->ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
+	if (IS_ERR(priv->ctx))
+		return -ENODEV;
+
+	/* Open first session with rtc Pseudo Trusted App */
+	export_uuid(sess_arg.uuid, &rtc_device->id.uuid);
+	sess_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
+
+	ret = tee_client_open_session(priv->ctx, &sess_arg, NULL);
+	if (ret < 0 || sess_arg.ret != 0) {
+		dev_err(dev, "tee_client_open_session failed, err: %x\n", sess_arg.ret);
+		err = -EINVAL;
+		goto out_ctx;
+	}
+	priv->session_id = sess_arg.session;
+
+	/*
+	 * Shared memory is used for passing an instance of either struct optee_rtc_info,
+	 * struct optee_rtc_time or struct optee_rtc_alarm to OP-TEE service.
+	 * The former is by definition large enough to cover both parameter cases.
+	 */
+	shm = tee_shm_alloc_kernel_buf(priv->ctx, sizeof(struct optee_rtc_info));
+	if (IS_ERR(shm)) {
+		dev_err(priv->dev, "tee_shm_alloc_kernel_buf failed\n");
+		err = PTR_ERR(shm);
+		goto out_sess;
+	}
+
+	priv->shm = shm;
+	priv->dev = dev;
+	dev_set_drvdata(dev, priv);
+
+	rtc->ops = &optee_rtc_ops;
+
+	err = optee_rtc_read_info(dev, rtc, &priv->features);
+	if (err) {
+		dev_err(dev, "Failed to get RTC features from OP-TEE\n");
+		goto out_shm;
+	}
+
+	/* Handle feature's related setup before registering to rtc framework */
+	if (priv->features & TA_RTC_FEATURE_ALARM) {
+		priv->alarm_task = kthread_create(optee_rtc_handle_alarm_event,
+						  priv, "rtc_alarm_evt");
+		if (IS_ERR(priv->alarm_task)) {
+			dev_err(dev, "Failed to create alarm thread\n");
+			err = PTR_ERR(priv->alarm_task);
+			goto out_shm;
+		}
+
+		/*
+		 * In case of supported alarm feature on optee side, we create a kthread
+		 * that will, in a new optee session, call a PTA interface "rtc_wait_alarm".
+		 * This call return in case of alarm and in case of canceled alarm.
+		 * The new optee session is therefore only needed in this case as we cannot
+		 * use the same session for parallel calls to optee PTA.
+		 * Hence one session is reserved to wait for alarms and the other to make
+		 * standard calls to RTC PTA.
+		 */
+
+		/* Open second session with rtc Trusted App */
+		export_uuid(sess2_arg.uuid, &rtc_device->id.uuid);
+		sess2_arg.clnt_login = TEE_IOCTL_LOGIN_REE_KERNEL;
+
+		ret = tee_client_open_session(priv->ctx, &sess2_arg, NULL);
+		if (ret < 0 || sess2_arg.ret != 0) {
+			dev_err(dev, "tee_client_open_session failed, err: %x\n", sess2_arg.ret);
+			err = -EINVAL;
+			goto out_thrd;
+		}
+		priv->session2_id = sess2_arg.session;
+
+		if (priv->features & TA_RTC_FEATURE_WAKEUP_ALARM)
+			device_init_wakeup(dev, true);
+	}
+
+	err = devm_rtc_register_device(rtc);
+	if (err)
+		goto out_wk;
+
+	/*
+	 * We must clear those bits after registering because registering a rtc_device
+	 * will set them if it sees that .set_offset and .set_alarm are provided.
+	 */
+	if (!(priv->features & TA_RTC_FEATURE_CORRECTION))
+		clear_bit(RTC_FEATURE_CORRECTION, rtc->features);
+	if (!(priv->features & TA_RTC_FEATURE_ALARM))
+		clear_bit(RTC_FEATURE_ALARM, rtc->features);
+
+	/* Start the thread after the rtc is setup */
+	if (priv->alarm_task) {
+		wake_up_process(priv->alarm_task);
+		dev_dbg(dev, "Wait alarm thread successfully started\n");
+	}
+
+	return 0;
+out_wk:
+	if (priv->features & TA_RTC_FEATURE_ALARM) {
+		device_init_wakeup(dev, false);
+		tee_client_close_session(priv->ctx, priv->session2_id);
+	}
+out_thrd:
+	if (priv->features & TA_RTC_FEATURE_ALARM)
+		kthread_stop(priv->alarm_task);
+out_shm:
+	tee_shm_free(priv->shm);
+out_sess:
+	tee_client_close_session(priv->ctx, priv->session_id);
+out_ctx:
+	tee_client_close_context(priv->ctx);
+
+	return err;
+}
+
+static void optee_rtc_remove(struct tee_client_device *rtc_device)
+{
+	struct device *dev = &rtc_device->dev;
+	struct optee_rtc *priv = dev_get_drvdata(dev);
+
+	if (priv->features & TA_RTC_FEATURE_ALARM) {
+		optee_rtc_cancel_wait_alarm(dev);
+		kthread_stop(priv->alarm_task);
+		device_init_wakeup(dev, false);
+		tee_client_close_session(priv->ctx, priv->session2_id);
+	}
+
+	tee_shm_free(priv->shm);
+	tee_client_close_session(priv->ctx, priv->session_id);
+	tee_client_close_context(priv->ctx);
+}
+
+static int optee_rtc_suspend(struct device *dev)
+{
+	int res = optee_rtc_set_alarm_wake_status(dev, device_may_wakeup(dev));
+
+	if (res) {
+		dev_err(dev, "Unable to transmit wakeup information to optee rtc\n");
+		return res;
+	}
+
+	return 0;
+}
+
+static DEFINE_SIMPLE_DEV_PM_OPS(optee_rtc_pm_ops, optee_rtc_suspend, NULL);
+
+static const struct tee_client_device_id optee_rtc_id_table[] = {
+	{UUID_INIT(0xf389f8c8, 0x845f, 0x496c,
+		   0x8b, 0xbe, 0xd6, 0x4b, 0xd2, 0x4c, 0x92, 0xfd)},
+	{}
+};
+
+MODULE_DEVICE_TABLE(tee, optee_rtc_id_table);
+
+static struct tee_client_driver optee_rtc_driver = {
+	.id_table	= optee_rtc_id_table,
+	.probe		= optee_rtc_probe,
+	.remove		= optee_rtc_remove,
+	.driver		= {
+		.name		= "optee_rtc",
+		.pm		= pm_sleep_ptr(&optee_rtc_pm_ops),
+	},
+};
+
+module_tee_client_driver(optee_rtc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Clément Léger <clement.leger@bootlin.com>");
+MODULE_DESCRIPTION("OP-TEE based RTC driver");