selftests/bpf: Add a test for objects stuck in free_by_rcu_ttracegrafted

Delete all elements of BPF_F_NO_PREALLOC hash map in one batch. The first
free_bulk() starts RCU tasks trace GP and the rest of the elements are
freed while it's in flight. Wait for call_rcu_ttrace_in_progress to clear
in bpf_mem_cache of every cpu and check that free_by_rcu_ttrace and
waiting_for_gp_ttrace lists are empty.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20260930095920.601738-4-alexei.starovoitov@gmail.com
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>

1 files changed, 180 insertions, 0 deletions

diff --git a/drivers/acpi/fan_hwmon.c b/drivers/acpi/fan_hwmon.c
new file mode 100644
index 000000000..d3374f8f5
--- /dev/null
+++ b/drivers/acpi/fan_hwmon.c
@@ -0,0 +1,180 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * hwmon interface for the ACPI Fan driver.
+ *
+ * Copyright (C) 2024 Armin Wolf <W_Armin@gmx.de>
+ */
+
+#include <linux/acpi.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/limits.h>
+#include <linux/types.h>
+#include <linux/units.h>
+
+#include "fan.h"
+
+static struct acpi_fan_fps *acpi_fan_get_current_fps(struct acpi_fan *fan, u64 control)
+{
+	unsigned int i;
+
+	for (i = 0; i < fan->fps_count; i++) {
+		if (fan->fps[i].control == control)
+			return &fan->fps[i];
+	}
+
+	return NULL;
+}
+
+static umode_t acpi_fan_hwmon_is_visible(const void *drvdata, enum hwmon_sensor_types type,
+					 u32 attr, int channel)
+{
+	const struct acpi_fan *fan = drvdata;
+	unsigned int i;
+
+	switch (type) {
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_input:
+			return 0444;
+		case hwmon_fan_target:
+			/* Only acpi4 fans support fan control. */
+			if (!fan->acpi4)
+				return 0;
+
+			/*
+			 * When in fine grain control mode, not every fan control value
+			 * has an associated fan performance state.
+			 */
+			if (fan->fif.fine_grain_ctrl)
+				return 0;
+
+			return 0444;
+		default:
+			return 0;
+		}
+	case hwmon_power:
+		switch (attr) {
+		case hwmon_power_input:
+			/* Only acpi4 fans support fan control. */
+			if (!fan->acpi4)
+				return 0;
+
+			/*
+			 * When in fine grain control mode, not every fan control value
+			 * has an associated fan performance state.
+			 */
+			if (fan->fif.fine_grain_ctrl)
+				return 0;
+
+			/*
+			 * When all fan performance states contain no valid power data,
+			 * when the associated attribute should not be created.
+			 */
+			for (i = 0; i < fan->fps_count; i++) {
+				if (acpi_fan_power_valid(fan->fps[i].power))
+					return 0444;
+			}
+
+			return 0;
+		default:
+			return 0;
+		}
+	default:
+		return 0;
+	}
+}
+
+static int acpi_fan_hwmon_read(struct device *dev, enum hwmon_sensor_types type, u32 attr,
+			       int channel, long *val)
+{
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+	struct acpi_fan_fps *fps;
+	struct acpi_fan_fst fst;
+	int ret;
+
+	ret = acpi_fan_get_fst(fan->handle, &fst);
+	if (ret < 0)
+		return ret;
+
+	switch (type) {
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_input:
+			if (!acpi_fan_speed_valid(fst.speed))
+				return -ENODEV;
+
+			if (fst.speed > LONG_MAX)
+				return -EOVERFLOW;
+
+			*val = fst.speed;
+			return 0;
+		case hwmon_fan_target:
+			fps = acpi_fan_get_current_fps(fan, fst.control);
+			if (!fps)
+				return -EIO;
+
+			if (fps->speed > LONG_MAX)
+				return -EOVERFLOW;
+
+			*val = fps->speed;
+			return 0;
+		default:
+			return -EOPNOTSUPP;
+		}
+	case hwmon_power:
+		switch (attr) {
+		case hwmon_power_input:
+			fps = acpi_fan_get_current_fps(fan, fst.control);
+			if (!fps)
+				return -EIO;
+
+			if (!acpi_fan_power_valid(fps->power))
+				return -ENODEV;
+
+			if (fps->power > LONG_MAX / MICROWATT_PER_MILLIWATT)
+				return -EOVERFLOW;
+
+			*val = fps->power * MICROWATT_PER_MILLIWATT;
+			return 0;
+		default:
+			return -EOPNOTSUPP;
+		}
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static const struct hwmon_ops acpi_fan_hwmon_ops = {
+	.is_visible = acpi_fan_hwmon_is_visible,
+	.read = acpi_fan_hwmon_read,
+};
+
+static const struct hwmon_channel_info * const acpi_fan_hwmon_info[] = {
+	HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_TARGET),
+	HWMON_CHANNEL_INFO(power, HWMON_P_INPUT),
+	NULL
+};
+
+static const struct hwmon_chip_info acpi_fan_hwmon_chip_info = {
+	.ops = &acpi_fan_hwmon_ops,
+	.info = acpi_fan_hwmon_info,
+};
+
+void acpi_fan_notify_hwmon(struct device *dev)
+{
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+
+	hwmon_notify_event(fan->hdev, hwmon_fan, hwmon_fan_input, 0);
+}
+
+int devm_acpi_fan_create_hwmon(struct device *dev)
+{
+	struct acpi_fan *fan = dev_get_drvdata(dev);
+
+	fan->hdev = devm_hwmon_device_register_with_info(dev, "acpi_fan", fan,
+							 &acpi_fan_hwmon_chip_info, NULL);
+
+	return PTR_ERR_OR_ZERO(fan->hdev);
+}