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, 408 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-mt7622.c b/drivers/rtc/rtc-mt7622.c
new file mode 100644
index 000000000..9e17dd09d
--- /dev/null
+++ b/drivers/rtc/rtc-mt7622.c
@@ -0,0 +1,408 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for MediaTek SoC based RTC
+ *
+ * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+#define MTK_RTC_DEV KBUILD_MODNAME
+
+#define MTK_RTC_PWRCHK1		0x4
+#define	RTC_PWRCHK1_MAGIC	0xc6
+
+#define MTK_RTC_PWRCHK2		0x8
+#define	RTC_PWRCHK2_MAGIC	0x9a
+
+#define MTK_RTC_KEY		0xc
+#define	RTC_KEY_MAGIC		0x59
+
+#define MTK_RTC_PROT1		0x10
+#define	RTC_PROT1_MAGIC		0xa3
+
+#define MTK_RTC_PROT2		0x14
+#define	RTC_PROT2_MAGIC		0x57
+
+#define MTK_RTC_PROT3		0x18
+#define	RTC_PROT3_MAGIC		0x67
+
+#define MTK_RTC_PROT4		0x1c
+#define	RTC_PROT4_MAGIC		0xd2
+
+#define MTK_RTC_CTL		0x20
+#define	RTC_RC_STOP		BIT(0)
+
+#define MTK_RTC_DEBNCE		0x2c
+#define	RTC_DEBNCE_MASK		GENMASK(2, 0)
+
+#define MTK_RTC_INT		0x30
+#define RTC_INT_AL_STA		BIT(4)
+
+/*
+ * Ranges from 0x40 to 0x78 provide RTC time setup for year, month,
+ * day of month, day of week, hour, minute and second.
+ */
+#define MTK_RTC_TREG(_t, _f)	(0x40 + (0x4 * (_f)) + ((_t) * 0x20))
+
+#define MTK_RTC_AL_CTL		0x7c
+#define	RTC_AL_EN		BIT(0)
+#define	RTC_AL_ALL		GENMASK(7, 0)
+
+/*
+ * The offset is used in the translation for the year between in struct
+ * rtc_time and in hardware register MTK_RTC_TREG(x,MTK_YEA)
+ */
+#define MTK_RTC_TM_YR_OFFSET	100
+
+/*
+ * The lowest value for the valid tm_year. RTC hardware would take incorrectly
+ * tm_year 100 as not a leap year and thus it is also required being excluded
+ * from the valid options.
+ */
+#define MTK_RTC_TM_YR_L		(MTK_RTC_TM_YR_OFFSET + 1)
+
+/*
+ * The most year the RTC can hold is 99 and the next to 99 in year register
+ * would be wraparound to 0, for MT7622.
+ */
+#define MTK_RTC_HW_YR_LIMIT	99
+
+/* The highest value for the valid tm_year */
+#define MTK_RTC_TM_YR_H		(MTK_RTC_TM_YR_OFFSET + MTK_RTC_HW_YR_LIMIT)
+
+/* Simple macro helps to check whether the hardware supports the tm_year */
+#define MTK_RTC_TM_YR_VALID(_y)	((_y) >= MTK_RTC_TM_YR_L && \
+				 (_y) <= MTK_RTC_TM_YR_H)
+
+/* Types of the function the RTC provides are time counter and alarm. */
+enum {
+	MTK_TC,
+	MTK_AL,
+};
+
+/* Indexes are used for the pointer to relevant registers in MTK_RTC_TREG */
+enum {
+	MTK_YEA,
+	MTK_MON,
+	MTK_DOM,
+	MTK_DOW,
+	MTK_HOU,
+	MTK_MIN,
+	MTK_SEC
+};
+
+struct mtk_rtc {
+	struct rtc_device *rtc;
+	void __iomem *base;
+	int irq;
+	struct clk *clk;
+};
+
+static void mtk_w32(struct mtk_rtc *rtc, u32 reg, u32 val)
+{
+	writel_relaxed(val, rtc->base + reg);
+}
+
+static u32 mtk_r32(struct mtk_rtc *rtc, u32 reg)
+{
+	return readl_relaxed(rtc->base + reg);
+}
+
+static void mtk_rmw(struct mtk_rtc *rtc, u32 reg, u32 mask, u32 set)
+{
+	u32 val;
+
+	val = mtk_r32(rtc, reg);
+	val &= ~mask;
+	val |= set;
+	mtk_w32(rtc, reg, val);
+}
+
+static void mtk_set(struct mtk_rtc *rtc, u32 reg, u32 val)
+{
+	mtk_rmw(rtc, reg, 0, val);
+}
+
+static void mtk_clr(struct mtk_rtc *rtc, u32 reg, u32 val)
+{
+	mtk_rmw(rtc, reg, val, 0);
+}
+
+static void mtk_rtc_hw_init(struct mtk_rtc *hw)
+{
+	/* The setup of the init sequence is for allowing RTC got to work */
+	mtk_w32(hw, MTK_RTC_PWRCHK1, RTC_PWRCHK1_MAGIC);
+	mtk_w32(hw, MTK_RTC_PWRCHK2, RTC_PWRCHK2_MAGIC);
+	mtk_w32(hw, MTK_RTC_KEY, RTC_KEY_MAGIC);
+	mtk_w32(hw, MTK_RTC_PROT1, RTC_PROT1_MAGIC);
+	mtk_w32(hw, MTK_RTC_PROT2, RTC_PROT2_MAGIC);
+	mtk_w32(hw, MTK_RTC_PROT3, RTC_PROT3_MAGIC);
+	mtk_w32(hw, MTK_RTC_PROT4, RTC_PROT4_MAGIC);
+	mtk_rmw(hw, MTK_RTC_DEBNCE, RTC_DEBNCE_MASK, 0);
+	mtk_clr(hw, MTK_RTC_CTL, RTC_RC_STOP);
+}
+
+static void mtk_rtc_get_alarm_or_time(struct mtk_rtc *hw, struct rtc_time *tm,
+				      int time_alarm)
+{
+	u32 year, mon, mday, wday, hour, min, sec;
+
+	/*
+	 * Read again until the field of the second is not changed which
+	 * ensures all fields in the consistent state. Note that MTK_SEC must
+	 * be read first. In this way, it guarantees the others remain not
+	 * changed when the results for two MTK_SEC consecutive reads are same.
+	 */
+	do {
+		sec = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC));
+		min = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN));
+		hour = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU));
+		wday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW));
+		mday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM));
+		mon = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MON));
+		year = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA));
+	} while (sec != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC)));
+
+	tm->tm_sec  = sec;
+	tm->tm_min  = min;
+	tm->tm_hour = hour;
+	tm->tm_wday = wday;
+	tm->tm_mday = mday;
+	tm->tm_mon  = mon - 1;
+
+	/* Rebase to the absolute year which userspace queries */
+	tm->tm_year = year + MTK_RTC_TM_YR_OFFSET;
+}
+
+static void mtk_rtc_set_alarm_or_time(struct mtk_rtc *hw, struct rtc_time *tm,
+				      int time_alarm)
+{
+	u32 year;
+
+	/* Rebase to the relative year which RTC hardware requires */
+	year = tm->tm_year - MTK_RTC_TM_YR_OFFSET;
+
+	mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA), year);
+	mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_MON), tm->tm_mon + 1);
+	mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW), tm->tm_wday);
+	mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM), tm->tm_mday);
+	mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU), tm->tm_hour);
+	mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN), tm->tm_min);
+	mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC), tm->tm_sec);
+}
+
+static irqreturn_t mtk_rtc_alarmirq(int irq, void *id)
+{
+	struct mtk_rtc *hw = (struct mtk_rtc *)id;
+	u32 irq_sta;
+
+	irq_sta = mtk_r32(hw, MTK_RTC_INT);
+	if (irq_sta & RTC_INT_AL_STA) {
+		/* Stop alarm also implicitly disables the alarm interrupt */
+		mtk_w32(hw, MTK_RTC_AL_CTL, 0);
+		rtc_update_irq(hw->rtc, 1, RTC_IRQF | RTC_AF);
+
+		/* Ack alarm interrupt status */
+		mtk_w32(hw, MTK_RTC_INT, RTC_INT_AL_STA);
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static int mtk_rtc_gettime(struct device *dev, struct rtc_time *tm)
+{
+	struct mtk_rtc *hw = dev_get_drvdata(dev);
+
+	mtk_rtc_get_alarm_or_time(hw, tm, MTK_TC);
+
+	return 0;
+}
+
+static int mtk_rtc_settime(struct device *dev, struct rtc_time *tm)
+{
+	struct mtk_rtc *hw = dev_get_drvdata(dev);
+
+	if (!MTK_RTC_TM_YR_VALID(tm->tm_year))
+		return -EINVAL;
+
+	/* Stop time counter before setting a new one*/
+	mtk_set(hw, MTK_RTC_CTL, RTC_RC_STOP);
+
+	mtk_rtc_set_alarm_or_time(hw, tm, MTK_TC);
+
+	/* Restart the time counter */
+	mtk_clr(hw, MTK_RTC_CTL, RTC_RC_STOP);
+
+	return 0;
+}
+
+static int mtk_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
+{
+	struct mtk_rtc *hw = dev_get_drvdata(dev);
+	struct rtc_time *alrm_tm = &wkalrm->time;
+
+	mtk_rtc_get_alarm_or_time(hw, alrm_tm, MTK_AL);
+
+	wkalrm->enabled = !!(mtk_r32(hw, MTK_RTC_AL_CTL) & RTC_AL_EN);
+	wkalrm->pending = !!(mtk_r32(hw, MTK_RTC_INT) & RTC_INT_AL_STA);
+
+	return 0;
+}
+
+static int mtk_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm)
+{
+	struct mtk_rtc *hw = dev_get_drvdata(dev);
+	struct rtc_time *alrm_tm = &wkalrm->time;
+
+	if (!MTK_RTC_TM_YR_VALID(alrm_tm->tm_year))
+		return -EINVAL;
+
+	/*
+	 * Stop the alarm also implicitly including disables interrupt before
+	 * setting a new one.
+	 */
+	mtk_clr(hw, MTK_RTC_AL_CTL, RTC_AL_EN);
+
+	/*
+	 * Avoid contention between mtk_rtc_setalarm and IRQ handler so that
+	 * disabling the interrupt and awaiting for pending IRQ handler to
+	 * complete.
+	 */
+	synchronize_irq(hw->irq);
+
+	mtk_rtc_set_alarm_or_time(hw, alrm_tm, MTK_AL);
+
+	/* Restart the alarm with the new setup */
+	mtk_w32(hw, MTK_RTC_AL_CTL, RTC_AL_ALL);
+
+	return 0;
+}
+
+static const struct rtc_class_ops mtk_rtc_ops = {
+	.read_time		= mtk_rtc_gettime,
+	.set_time		= mtk_rtc_settime,
+	.read_alarm		= mtk_rtc_getalarm,
+	.set_alarm		= mtk_rtc_setalarm,
+};
+
+static const struct of_device_id mtk_rtc_match[] = {
+	{ .compatible = "mediatek,mt7622-rtc" },
+	{ .compatible = "mediatek,soc-rtc" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, mtk_rtc_match);
+
+static int mtk_rtc_probe(struct platform_device *pdev)
+{
+	struct mtk_rtc *hw;
+	int ret;
+
+	hw = devm_kzalloc(&pdev->dev, sizeof(*hw), GFP_KERNEL);
+	if (!hw)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, hw);
+
+	hw->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(hw->base))
+		return PTR_ERR(hw->base);
+
+	hw->clk = devm_clk_get(&pdev->dev, "rtc");
+	if (IS_ERR(hw->clk)) {
+		dev_err(&pdev->dev, "No clock\n");
+		return PTR_ERR(hw->clk);
+	}
+
+	ret = clk_prepare_enable(hw->clk);
+	if (ret)
+		return ret;
+
+	hw->irq = platform_get_irq(pdev, 0);
+	if (hw->irq < 0) {
+		ret = hw->irq;
+		goto err;
+	}
+
+	ret = devm_request_irq(&pdev->dev, hw->irq, mtk_rtc_alarmirq,
+			       0, dev_name(&pdev->dev), hw);
+	if (ret) {
+		dev_err(&pdev->dev, "Can't request IRQ\n");
+		goto err;
+	}
+
+	mtk_rtc_hw_init(hw);
+
+	device_init_wakeup(&pdev->dev, true);
+
+	hw->rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+					   &mtk_rtc_ops, THIS_MODULE);
+	if (IS_ERR(hw->rtc)) {
+		ret = PTR_ERR(hw->rtc);
+		dev_err(&pdev->dev, "Unable to register device\n");
+		goto err;
+	}
+
+	return 0;
+err:
+	clk_disable_unprepare(hw->clk);
+
+	return ret;
+}
+
+static void mtk_rtc_remove(struct platform_device *pdev)
+{
+	struct mtk_rtc *hw = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(hw->clk);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mtk_rtc_suspend(struct device *dev)
+{
+	struct mtk_rtc *hw = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		enable_irq_wake(hw->irq);
+
+	return 0;
+}
+
+static int mtk_rtc_resume(struct device *dev)
+{
+	struct mtk_rtc *hw = dev_get_drvdata(dev);
+
+	if (device_may_wakeup(dev))
+		disable_irq_wake(hw->irq);
+
+	return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(mtk_rtc_pm_ops, mtk_rtc_suspend, mtk_rtc_resume);
+
+#define MTK_RTC_PM_OPS (&mtk_rtc_pm_ops)
+#else	/* CONFIG_PM */
+#define MTK_RTC_PM_OPS NULL
+#endif	/* CONFIG_PM */
+
+static struct platform_driver mtk_rtc_driver = {
+	.probe	= mtk_rtc_probe,
+	.remove = mtk_rtc_remove,
+	.driver = {
+		.name = MTK_RTC_DEV,
+		.of_match_table = mtk_rtc_match,
+		.pm = MTK_RTC_PM_OPS,
+	},
+};
+
+module_platform_driver(mtk_rtc_driver);
+
+MODULE_DESCRIPTION("MediaTek SoC based RTC Driver");
+MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>");
+MODULE_LICENSE("GPL");