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/gpio/gpio-octeon.c | 140 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 140 insertions(+) create mode 100644 drivers/gpio/gpio-octeon.c (limited to 'drivers/gpio/gpio-octeon.c') diff --git a/drivers/gpio/gpio-octeon.c b/drivers/gpio/gpio-octeon.c new file mode 100644 index 000000000..777e20c60 --- /dev/null +++ b/drivers/gpio/gpio-octeon.c @@ -0,0 +1,140 @@ +/* + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + * + * Copyright (C) 2011, 2012 Cavium Inc. + */ + +#include +#include +#include +#include +#include + +#include +#include + +#define RX_DAT 0x80 +#define TX_SET 0x88 +#define TX_CLEAR 0x90 +/* + * The address offset of the GPIO configuration register for a given + * line. + */ +static unsigned int bit_cfg_reg(unsigned int offset) +{ + /* + * The register stride is 8, with a discontinuity after the + * first 16. + */ + if (offset < 16) + return 8 * offset; + else + return 8 * (offset - 16) + 0x100; +} + +struct octeon_gpio { + struct gpio_chip chip; + u64 register_base; +}; + +static int octeon_gpio_dir_in(struct gpio_chip *chip, unsigned offset) +{ + struct octeon_gpio *gpio = gpiochip_get_data(chip); + + cvmx_write_csr(gpio->register_base + bit_cfg_reg(offset), 0); + return 0; +} + +static int octeon_gpio_set(struct gpio_chip *chip, unsigned int offset, + int value) +{ + struct octeon_gpio *gpio = gpiochip_get_data(chip); + u64 mask = 1ull << offset; + u64 reg = gpio->register_base + (value ? TX_SET : TX_CLEAR); + cvmx_write_csr(reg, mask); + + return 0; +} + +static int octeon_gpio_dir_out(struct gpio_chip *chip, unsigned offset, + int value) +{ + struct octeon_gpio *gpio = gpiochip_get_data(chip); + union cvmx_gpio_bit_cfgx cfgx; + + octeon_gpio_set(chip, offset, value); + + cfgx.u64 = 0; + cfgx.s.tx_oe = 1; + + cvmx_write_csr(gpio->register_base + bit_cfg_reg(offset), cfgx.u64); + return 0; +} + +static int octeon_gpio_get(struct gpio_chip *chip, unsigned offset) +{ + struct octeon_gpio *gpio = gpiochip_get_data(chip); + u64 read_bits = cvmx_read_csr(gpio->register_base + RX_DAT); + + return ((1ull << offset) & read_bits) != 0; +} + +static int octeon_gpio_probe(struct platform_device *pdev) +{ + struct octeon_gpio *gpio; + struct gpio_chip *chip; + void __iomem *reg_base; + int err = 0; + + gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL); + if (!gpio) + return -ENOMEM; + chip = &gpio->chip; + + reg_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(reg_base)) + return PTR_ERR(reg_base); + + gpio->register_base = (u64)reg_base; + pdev->dev.platform_data = chip; + chip->label = "octeon-gpio"; + chip->parent = &pdev->dev; + chip->owner = THIS_MODULE; + chip->base = 0; + chip->can_sleep = false; + chip->ngpio = 20; + chip->direction_input = octeon_gpio_dir_in; + chip->get = octeon_gpio_get; + chip->direction_output = octeon_gpio_dir_out; + chip->set = octeon_gpio_set; + err = devm_gpiochip_add_data(&pdev->dev, chip, gpio); + if (err) + return err; + + dev_info(&pdev->dev, "OCTEON GPIO driver probed.\n"); + return 0; +} + +static const struct of_device_id octeon_gpio_match[] = { + { + .compatible = "cavium,octeon-3860-gpio", + }, + {}, +}; +MODULE_DEVICE_TABLE(of, octeon_gpio_match); + +static struct platform_driver octeon_gpio_driver = { + .driver = { + .name = "octeon_gpio", + .of_match_table = octeon_gpio_match, + }, + .probe = octeon_gpio_probe, +}; + +module_platform_driver(octeon_gpio_driver); + +MODULE_DESCRIPTION("Cavium Inc. OCTEON GPIO Driver"); +MODULE_AUTHOR("David Daney"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1