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/reset/reset-sky1-audss.c | 127 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 127 insertions(+) create mode 100644 drivers/reset/reset-sky1-audss.c (limited to 'drivers/reset/reset-sky1-audss.c') diff --git a/drivers/reset/reset-sky1-audss.c b/drivers/reset/reset-sky1-audss.c new file mode 100644 index 000000000..d9735db68 --- /dev/null +++ b/drivers/reset/reset-sky1-audss.c @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Cix Sky1 Audio Subsystem reset controller driver + * + * Copyright 2026 Cix Technology Group Co., Ltd. + */ + +#include + +#include +#include +#include +#include +#include +#include + +#define SKY1_RESET_SLEEP_US 50 + +#define AUDSS_SW_RST 0x78 + +struct sky1_audss_reset_map { + unsigned int offset; + unsigned int mask; +}; + +struct sky1_audss_reset { + struct reset_controller_dev rcdev; + struct regmap *regmap; + const struct sky1_audss_reset_map *map; +}; + +static const struct sky1_audss_reset_map sky1_audss_reset_map[] = { + [AUDSS_I2S0_SW_RST] = { AUDSS_SW_RST, BIT(0) }, + [AUDSS_I2S1_SW_RST] = { AUDSS_SW_RST, BIT(1) }, + [AUDSS_I2S2_SW_RST] = { AUDSS_SW_RST, BIT(2) }, + [AUDSS_I2S3_SW_RST] = { AUDSS_SW_RST, BIT(3) }, + [AUDSS_I2S4_SW_RST] = { AUDSS_SW_RST, BIT(4) }, + [AUDSS_I2S5_SW_RST] = { AUDSS_SW_RST, BIT(5) }, + [AUDSS_I2S6_SW_RST] = { AUDSS_SW_RST, BIT(6) }, + [AUDSS_I2S7_SW_RST] = { AUDSS_SW_RST, BIT(7) }, + [AUDSS_I2S8_SW_RST] = { AUDSS_SW_RST, BIT(8) }, + [AUDSS_I2S9_SW_RST] = { AUDSS_SW_RST, BIT(9) }, + [AUDSS_WDT_SW_RST] = { AUDSS_SW_RST, BIT(10) }, + [AUDSS_TIMER_SW_RST] = { AUDSS_SW_RST, BIT(11) }, + [AUDSS_MB0_SW_RST] = { AUDSS_SW_RST, BIT(12) }, + [AUDSS_MB1_SW_RST] = { AUDSS_SW_RST, BIT(13) }, + [AUDSS_HDA_SW_RST] = { AUDSS_SW_RST, BIT(14) }, + [AUDSS_DMAC_SW_RST] = { AUDSS_SW_RST, BIT(15) }, +}; + +static struct sky1_audss_reset *to_sky1_audss_reset(struct reset_controller_dev *rcdev) +{ + return container_of(rcdev, struct sky1_audss_reset, rcdev); +} + +static int sky1_audss_reset_set(struct reset_controller_dev *rcdev, + unsigned long id, bool assert) +{ + struct sky1_audss_reset *priv = to_sky1_audss_reset(rcdev); + const struct sky1_audss_reset_map *signal = &priv->map[id]; + int ret; + + ret = regmap_assign_bits(priv->regmap, signal->offset, + signal->mask, !assert); + if (ret) + return ret; + + fsleep(SKY1_RESET_SLEEP_US); + return 0; +} + +static int sky1_audss_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return sky1_audss_reset_set(rcdev, id, true); +} + +static int sky1_audss_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + return sky1_audss_reset_set(rcdev, id, false); +} + +static const struct reset_control_ops sky1_audss_reset_ops = { + .assert = sky1_audss_reset_assert, + .deassert = sky1_audss_reset_deassert, +}; + +static int sky1_audss_reset_probe(struct auxiliary_device *adev, + const struct auxiliary_device_id *id) +{ + struct sky1_audss_reset *priv; + struct device *dev = &adev->dev; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->regmap = dev_get_regmap(dev->parent, NULL); + if (!priv->regmap) + return dev_err_probe(dev, -ENODEV, "failed to get parent regmap\n"); + + priv->map = sky1_audss_reset_map; + priv->rcdev.owner = THIS_MODULE; + priv->rcdev.nr_resets = ARRAY_SIZE(sky1_audss_reset_map); + priv->rcdev.ops = &sky1_audss_reset_ops; + priv->rcdev.of_node = dev->of_node; + priv->rcdev.dev = dev; + + return devm_reset_controller_register(dev, &priv->rcdev); +} + +static const struct auxiliary_device_id sky1_audss_reset_ids[] = { + { .name = "clk_sky1_audss.reset" }, + { } +}; +MODULE_DEVICE_TABLE(auxiliary, sky1_audss_reset_ids); + +static struct auxiliary_driver sky1_audss_reset_driver = { + .probe = sky1_audss_reset_probe, + .id_table = sky1_audss_reset_ids, +}; +module_auxiliary_driver(sky1_audss_reset_driver); + +MODULE_AUTHOR("Joakim Zhang "); +MODULE_DESCRIPTION("Cix Sky1 Audio Subsystem reset driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1