From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- drivers/iio/accel/da280.c | 186 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 186 insertions(+) create mode 100644 drivers/iio/accel/da280.c (limited to 'drivers/iio/accel/da280.c') diff --git a/drivers/iio/accel/da280.c b/drivers/iio/accel/da280.c new file mode 100644 index 000000000..15acbe1c2 --- /dev/null +++ b/drivers/iio/accel/da280.c @@ -0,0 +1,186 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * IIO driver for the MiraMEMS DA217 and DA280 3-axis accelerometer and + * IIO driver for the MiraMEMS DA226 2-axis accelerometer + * + * Copyright (c) 2016 Hans de Goede + */ + +#include +#include +#include +#include +#include +#include + +#define DA280_REG_CHIP_ID 0x01 +#define DA280_REG_ACC_X_LSB 0x02 +#define DA280_REG_ACC_Y_LSB 0x04 +#define DA280_REG_ACC_Z_LSB 0x06 +#define DA280_REG_MODE_BW 0x11 + +#define DA280_CHIP_ID 0x13 +#define DA280_MODE_ENABLE 0x1e +#define DA280_MODE_DISABLE 0x9e + +/* + * a value of + or -4096 corresponds to + or - 1G + * scale = 9.81 / 4096 = 0.002395019 + */ + +static const int da280_nscale = 2395019; + +#define DA280_CHANNEL(reg, axis) { \ + .type = IIO_ACCEL, \ + .address = reg, \ + .modified = 1, \ + .channel2 = IIO_MOD_##axis, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ +} + +static const struct iio_chan_spec da280_channels[] = { + DA280_CHANNEL(DA280_REG_ACC_X_LSB, X), + DA280_CHANNEL(DA280_REG_ACC_Y_LSB, Y), + DA280_CHANNEL(DA280_REG_ACC_Z_LSB, Z), +}; + +struct da280_match_data { + const char *name; + int num_channels; +}; + +struct da280_data { + struct i2c_client *client; +}; + +static int da280_enable(struct i2c_client *client, bool enable) +{ + u8 data = enable ? DA280_MODE_ENABLE : DA280_MODE_DISABLE; + + return i2c_smbus_write_byte_data(client, DA280_REG_MODE_BW, data); +} + +static int da280_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct da280_data *data = iio_priv(indio_dev); + int ret; + + switch (mask) { + case IIO_CHAN_INFO_RAW: + ret = i2c_smbus_read_word_data(data->client, chan->address); + if (ret < 0) + return ret; + /* + * Values are 14 bits, stored as 16 bits with the 2 + * least significant bits always 0. + */ + *val = (short)ret >> 2; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + *val = 0; + *val2 = da280_nscale; + return IIO_VAL_INT_PLUS_NANO; + default: + return -EINVAL; + } +} + +static const struct iio_info da280_info = { + .read_raw = da280_read_raw, +}; + +static void da280_disable(void *client) +{ + da280_enable(client, false); +} + +static int da280_probe(struct i2c_client *client) +{ + const struct da280_match_data *match_data; + struct iio_dev *indio_dev; + struct da280_data *data; + int ret; + + ret = i2c_smbus_read_byte_data(client, DA280_REG_CHIP_ID); + if (ret != DA280_CHIP_ID) + return (ret < 0) ? ret : -ENODEV; + + match_data = i2c_get_match_data(client); + if (!match_data) { + dev_err(&client->dev, "Error match-data not set\n"); + return -EINVAL; + } + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + data = iio_priv(indio_dev); + data->client = client; + + indio_dev->info = &da280_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->channels = da280_channels; + indio_dev->num_channels = match_data->num_channels; + indio_dev->name = match_data->name; + + ret = da280_enable(client, true); + if (ret < 0) + return ret; + + ret = devm_add_action_or_reset(&client->dev, da280_disable, client); + if (ret) + return ret; + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static int da280_suspend(struct device *dev) +{ + return da280_enable(to_i2c_client(dev), false); +} + +static int da280_resume(struct device *dev) +{ + return da280_enable(to_i2c_client(dev), true); +} + +static DEFINE_SIMPLE_DEV_PM_OPS(da280_pm_ops, da280_suspend, da280_resume); + +static const struct da280_match_data da217_match_data = { "da217", 3 }; +static const struct da280_match_data da226_match_data = { "da226", 2 }; +static const struct da280_match_data da280_match_data = { "da280", 3 }; + +static const struct acpi_device_id da280_acpi_match[] = { + { "NSA2513", (kernel_ulong_t)&da217_match_data }, + { "MIRAACC", (kernel_ulong_t)&da280_match_data }, + { } +}; +MODULE_DEVICE_TABLE(acpi, da280_acpi_match); + +static const struct i2c_device_id da280_i2c_id[] = { + { .name = "da217", .driver_data = (kernel_ulong_t)&da217_match_data }, + { .name = "da226", .driver_data = (kernel_ulong_t)&da226_match_data }, + { .name = "da280", .driver_data = (kernel_ulong_t)&da280_match_data }, + { } +}; +MODULE_DEVICE_TABLE(i2c, da280_i2c_id); + +static struct i2c_driver da280_driver = { + .driver = { + .name = "da280", + .acpi_match_table = da280_acpi_match, + .pm = pm_sleep_ptr(&da280_pm_ops), + }, + .probe = da280_probe, + .id_table = da280_i2c_id, +}; + +module_i2c_driver(da280_driver); + +MODULE_AUTHOR("Hans de Goede "); +MODULE_DESCRIPTION("MiraMEMS DA280 3-Axis Accelerometer driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1