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

3 files changed, 346 insertions, 0 deletions

diff --git a/drivers/pmdomain/apple/Kconfig b/drivers/pmdomain/apple/Kconfig
new file mode 100644
index 000000000..a8973f805
--- /dev/null
+++ b/drivers/pmdomain/apple/Kconfig
@@ -0,0 +1,17 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+if ARCH_APPLE || COMPILE_TEST
+
+config APPLE_PMGR_PWRSTATE
+	bool "Apple SoC PMGR power state control"
+	depends on PM
+	select REGMAP
+	select MFD_SYSCON
+	select PM_GENERIC_DOMAINS
+	select RESET_CONTROLLER
+	help
+	  The PMGR block in Apple SoCs provides high-level power state
+	  controls for SoC devices. This driver manages them through the
+	  generic power domain framework, and also provides reset support.
+
+endif
diff --git a/drivers/pmdomain/apple/Makefile b/drivers/pmdomain/apple/Makefile
new file mode 100644
index 000000000..53665af63
--- /dev/null
+++ b/drivers/pmdomain/apple/Makefile
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_APPLE_PMGR_PWRSTATE)	+= pmgr-pwrstate.o
diff --git a/drivers/pmdomain/apple/pmgr-pwrstate.c b/drivers/pmdomain/apple/pmgr-pwrstate.c
new file mode 100644
index 000000000..82c33cf72
--- /dev/null
+++ b/drivers/pmdomain/apple/pmgr-pwrstate.c
@@ -0,0 +1,327 @@
+// SPDX-License-Identifier: GPL-2.0-only OR MIT
+/*
+ * Apple SoC PMGR device power state driver
+ *
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <linux/bitops.h>
+#include <linux/bitfield.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/pm_domain.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/reset-controller.h>
+#include <linux/module.h>
+
+#define APPLE_PMGR_RESET        BIT(31)
+#define APPLE_PMGR_AUTO_ENABLE  BIT(28)
+#define APPLE_PMGR_PS_AUTO      GENMASK(27, 24)
+#define APPLE_PMGR_PS_MIN       GENMASK(19, 16)
+#define APPLE_PMGR_PARENT_OFF   BIT(11)
+#define APPLE_PMGR_DEV_DISABLE  BIT(10)
+#define APPLE_PMGR_WAS_CLKGATED BIT(9)
+#define APPLE_PMGR_WAS_PWRGATED BIT(8)
+#define APPLE_PMGR_PS_ACTUAL    GENMASK(7, 4)
+#define APPLE_PMGR_PS_TARGET    GENMASK(3, 0)
+
+#define APPLE_PMGR_FLAGS        (APPLE_PMGR_WAS_CLKGATED | APPLE_PMGR_WAS_PWRGATED)
+
+#define APPLE_PMGR_PS_ACTIVE    0xf
+#define APPLE_PMGR_PS_CLKGATE   0x4
+#define APPLE_PMGR_PS_PWRGATE   0x0
+
+#define APPLE_PMGR_PS_SET_TIMEOUT 100
+#define APPLE_PMGR_RESET_TIME 1
+
+struct apple_pmgr_ps {
+	struct device *dev;
+	struct generic_pm_domain genpd;
+	struct reset_controller_dev rcdev;
+	struct regmap *regmap;
+	u32 offset;
+	u32 min_state;
+};
+
+#define genpd_to_apple_pmgr_ps(_genpd) container_of(_genpd, struct apple_pmgr_ps, genpd)
+#define rcdev_to_apple_pmgr_ps(_rcdev) container_of(_rcdev, struct apple_pmgr_ps, rcdev)
+
+static int apple_pmgr_ps_set(struct generic_pm_domain *genpd, u32 pstate, bool auto_enable)
+{
+	int ret;
+	struct apple_pmgr_ps *ps = genpd_to_apple_pmgr_ps(genpd);
+	u32 reg;
+
+	ret = regmap_read(ps->regmap, ps->offset, &reg);
+	if (ret < 0)
+		return ret;
+
+	/* Resets are synchronous, and only work if the device is powered and clocked. */
+	if (reg & APPLE_PMGR_RESET && pstate != APPLE_PMGR_PS_ACTIVE)
+		dev_err(ps->dev, "PS %s: powering off with RESET active\n",
+			genpd->name);
+
+	reg &= ~(APPLE_PMGR_AUTO_ENABLE | APPLE_PMGR_FLAGS | APPLE_PMGR_PS_TARGET);
+	reg |= FIELD_PREP(APPLE_PMGR_PS_TARGET, pstate);
+
+	dev_dbg(ps->dev, "PS %s: pwrstate = 0x%x: 0x%x\n", genpd->name, pstate, reg);
+
+	regmap_write(ps->regmap, ps->offset, reg);
+
+	ret = regmap_read_poll_timeout_atomic(
+		ps->regmap, ps->offset, reg,
+		(FIELD_GET(APPLE_PMGR_PS_ACTUAL, reg) == pstate), 1,
+		APPLE_PMGR_PS_SET_TIMEOUT);
+	if (ret < 0)
+		dev_err(ps->dev, "PS %s: Failed to reach power state 0x%x (now: 0x%x)\n",
+			genpd->name, pstate, reg);
+
+	if (auto_enable) {
+		/* Not all devices implement this; this is a no-op where not implemented. */
+		reg &= ~APPLE_PMGR_FLAGS;
+		reg |= APPLE_PMGR_AUTO_ENABLE;
+		regmap_write(ps->regmap, ps->offset, reg);
+	}
+
+	return ret;
+}
+
+static bool apple_pmgr_ps_is_active(struct apple_pmgr_ps *ps)
+{
+	u32 reg = 0;
+
+	regmap_read(ps->regmap, ps->offset, &reg);
+	/*
+	 * We consider domains as active if they are actually on, or if they have auto-PM
+	 * enabled and the intended target is on.
+	 */
+	return (FIELD_GET(APPLE_PMGR_PS_ACTUAL, reg) == APPLE_PMGR_PS_ACTIVE ||
+		(FIELD_GET(APPLE_PMGR_PS_TARGET, reg) == APPLE_PMGR_PS_ACTIVE &&
+		 reg & APPLE_PMGR_AUTO_ENABLE));
+}
+
+static int apple_pmgr_ps_power_on(struct generic_pm_domain *genpd)
+{
+	return apple_pmgr_ps_set(genpd, APPLE_PMGR_PS_ACTIVE, true);
+}
+
+static int apple_pmgr_ps_power_off(struct generic_pm_domain *genpd)
+{
+	return apple_pmgr_ps_set(genpd, APPLE_PMGR_PS_PWRGATE, false);
+}
+
+static int apple_pmgr_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	struct apple_pmgr_ps *ps = rcdev_to_apple_pmgr_ps(rcdev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&ps->genpd.slock, flags);
+
+	if (ps->genpd.status == GENPD_STATE_OFF)
+		dev_err(ps->dev, "PS 0x%x: asserting RESET while powered down\n", ps->offset);
+
+	dev_dbg(ps->dev, "PS 0x%x: assert reset\n", ps->offset);
+	/* Quiesce device before asserting reset */
+	regmap_update_bits(ps->regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_DEV_DISABLE,
+			   APPLE_PMGR_DEV_DISABLE);
+	regmap_update_bits(ps->regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_RESET,
+			   APPLE_PMGR_RESET);
+
+	spin_unlock_irqrestore(&ps->genpd.slock, flags);
+
+	return 0;
+}
+
+static int apple_pmgr_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	struct apple_pmgr_ps *ps = rcdev_to_apple_pmgr_ps(rcdev);
+	unsigned long flags;
+
+	spin_lock_irqsave(&ps->genpd.slock, flags);
+
+	dev_dbg(ps->dev, "PS 0x%x: deassert reset\n", ps->offset);
+	regmap_update_bits(ps->regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_RESET, 0);
+	regmap_update_bits(ps->regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_DEV_DISABLE, 0);
+
+	if (ps->genpd.status == GENPD_STATE_OFF)
+		dev_err(ps->dev, "PS 0x%x: RESET was deasserted while powered down\n", ps->offset);
+
+	spin_unlock_irqrestore(&ps->genpd.slock, flags);
+
+	return 0;
+}
+
+static int apple_pmgr_reset_reset(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	int ret;
+
+	ret = apple_pmgr_reset_assert(rcdev, id);
+	if (ret)
+		return ret;
+
+	usleep_range(APPLE_PMGR_RESET_TIME, 2 * APPLE_PMGR_RESET_TIME);
+
+	return apple_pmgr_reset_deassert(rcdev, id);
+}
+
+static int apple_pmgr_reset_status(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	struct apple_pmgr_ps *ps = rcdev_to_apple_pmgr_ps(rcdev);
+	u32 reg = 0;
+
+	regmap_read(ps->regmap, ps->offset, &reg);
+
+	return !!(reg & APPLE_PMGR_RESET);
+}
+
+static const struct reset_control_ops apple_pmgr_reset_ops = {
+	.assert		= apple_pmgr_reset_assert,
+	.deassert	= apple_pmgr_reset_deassert,
+	.reset		= apple_pmgr_reset_reset,
+	.status		= apple_pmgr_reset_status,
+};
+
+static int apple_pmgr_reset_xlate(struct reset_controller_dev *rcdev,
+				  const struct of_phandle_args *reset_spec)
+{
+	return 0;
+}
+
+static int apple_pmgr_ps_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = dev->of_node;
+	struct apple_pmgr_ps *ps;
+	struct regmap *regmap;
+	struct of_phandle_iterator it;
+	int ret;
+	const char *name;
+	bool active;
+
+	regmap = syscon_node_to_regmap(node->parent);
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	ps = devm_kzalloc(dev, sizeof(*ps), GFP_KERNEL);
+	if (!ps)
+		return -ENOMEM;
+
+	ps->dev = dev;
+	ps->regmap = regmap;
+
+	ret = of_property_read_string(node, "label", &name);
+	if (ret < 0) {
+		dev_err(dev, "missing label property\n");
+		return ret;
+	}
+
+	ret = of_property_read_u32(node, "reg", &ps->offset);
+	if (ret < 0) {
+		dev_err(dev, "missing reg property\n");
+		return ret;
+	}
+
+	ps->genpd.flags |= GENPD_FLAG_IRQ_SAFE;
+	ps->genpd.name = name;
+	ps->genpd.power_on = apple_pmgr_ps_power_on;
+	ps->genpd.power_off = apple_pmgr_ps_power_off;
+
+	ret = of_property_read_u32(node, "apple,min-state", &ps->min_state);
+	if (ret == 0 && ps->min_state <= APPLE_PMGR_PS_ACTIVE)
+		regmap_update_bits(regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_PS_MIN,
+				   FIELD_PREP(APPLE_PMGR_PS_MIN, ps->min_state));
+
+	active = apple_pmgr_ps_is_active(ps);
+	if (of_property_read_bool(node, "apple,always-on")) {
+		ps->genpd.flags |= GENPD_FLAG_ALWAYS_ON;
+		if (!active) {
+			dev_warn(dev, "always-on domain %s is not on at boot\n", name);
+			/* Turn it on so pm_genpd_init does not fail */
+			active = apple_pmgr_ps_power_on(&ps->genpd) == 0;
+		}
+	}
+
+	/* Turn on auto-PM if the domain is already on */
+	if (active)
+		regmap_update_bits(regmap, ps->offset, APPLE_PMGR_FLAGS | APPLE_PMGR_AUTO_ENABLE,
+				   APPLE_PMGR_AUTO_ENABLE);
+
+	ret = pm_genpd_init(&ps->genpd, NULL, !active);
+	if (ret < 0) {
+		dev_err(dev, "pm_genpd_init failed\n");
+		return ret;
+	}
+
+	ret = of_genpd_add_provider_simple(node, &ps->genpd);
+	if (ret < 0) {
+		dev_err(dev, "of_genpd_add_provider_simple failed\n");
+		return ret;
+	}
+
+	of_for_each_phandle(&it, ret, node, "power-domains", "#power-domain-cells", -1) {
+		struct of_phandle_args parent, child;
+
+		parent.np = it.node;
+		parent.args_count = of_phandle_iterator_args(&it, parent.args, MAX_PHANDLE_ARGS);
+		child.np = node;
+		child.args_count = 0;
+		ret = of_genpd_add_subdomain(&parent, &child);
+
+		if (ret == -EPROBE_DEFER) {
+			of_node_put(parent.np);
+			goto err_remove;
+		} else if (ret < 0) {
+			dev_err(dev, "failed to add to parent domain: %d (%s -> %s)\n",
+				ret, it.node->name, node->name);
+			of_node_put(parent.np);
+			goto err_remove;
+		}
+	}
+
+	/*
+	 * Do not participate in regular PM; parent power domains are handled via the
+	 * genpd hierarchy.
+	 */
+	pm_genpd_remove_device(dev);
+
+	ps->rcdev.owner = THIS_MODULE;
+	ps->rcdev.nr_resets = 1;
+	ps->rcdev.ops = &apple_pmgr_reset_ops;
+	ps->rcdev.of_node = dev->of_node;
+	ps->rcdev.of_reset_n_cells = 0;
+	ps->rcdev.of_xlate = apple_pmgr_reset_xlate;
+
+	ret = devm_reset_controller_register(dev, &ps->rcdev);
+	if (ret < 0)
+		goto err_remove;
+
+	return 0;
+err_remove:
+	of_genpd_del_provider(node);
+	pm_genpd_remove(&ps->genpd);
+	return ret;
+}
+
+static const struct of_device_id apple_pmgr_ps_of_match[] = {
+	{ .compatible = "apple,t8103-pmgr-pwrstate" },
+	{ .compatible = "apple,pmgr-pwrstate" },
+	{}
+};
+
+MODULE_DEVICE_TABLE(of, apple_pmgr_ps_of_match);
+
+static struct platform_driver apple_pmgr_ps_driver = {
+	.probe = apple_pmgr_ps_probe,
+	.driver = {
+		.name = "apple-pmgr-pwrstate",
+		.of_match_table = apple_pmgr_ps_of_match,
+	},
+};
+
+MODULE_AUTHOR("Hector Martin <marcan@marcan.st>");
+MODULE_DESCRIPTION("PMGR power state driver for Apple SoCs");
+
+module_platform_driver(apple_pmgr_ps_driver);