Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

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");