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 --- sound/ac97/Kconfig | 19 ++ sound/ac97/Makefile | 9 + sound/ac97/ac97_core.h | 13 ++ sound/ac97/bus.c | 526 +++++++++++++++++++++++++++++++++++++++++++ sound/ac97/codec.c | 12 + sound/ac97/snd_ac97_compat.c | 120 ++++++++++ 6 files changed, 699 insertions(+) create mode 100644 sound/ac97/Kconfig create mode 100644 sound/ac97/Makefile create mode 100644 sound/ac97/ac97_core.h create mode 100644 sound/ac97/bus.c create mode 100644 sound/ac97/codec.c create mode 100644 sound/ac97/snd_ac97_compat.c (limited to 'sound/ac97') diff --git a/sound/ac97/Kconfig b/sound/ac97/Kconfig new file mode 100644 index 000000000..f0e31f2bb --- /dev/null +++ b/sound/ac97/Kconfig @@ -0,0 +1,19 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# AC97 configuration +# + + +config AC97_BUS_NEW + tristate + help + This is the new AC97 bus type, successor of AC97_BUS. The ported + drivers which benefit from the AC97 automatic probing should "select" + this instead of the AC97_BUS. + Say Y here if you want to have AC97 devices, which are sound oriented + devices around an AC-Link. + +config AC97_BUS_COMPAT + bool + depends on AC97_BUS_NEW + depends on !AC97_BUS diff --git a/sound/ac97/Makefile b/sound/ac97/Makefile new file mode 100644 index 000000000..f5efa1ad7 --- /dev/null +++ b/sound/ac97/Makefile @@ -0,0 +1,9 @@ +# SPDX-License-Identifier: GPL-2.0-only +# +# make for AC97 bus drivers +# + +obj-$(CONFIG_AC97_BUS_NEW) += ac97.o + +ac97-y += bus.o codec.o +ac97-$(CONFIG_AC97_BUS_COMPAT) += snd_ac97_compat.o diff --git a/sound/ac97/ac97_core.h b/sound/ac97/ac97_core.h new file mode 100644 index 000000000..5a9677c3d --- /dev/null +++ b/sound/ac97/ac97_core.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2016 Robert Jarzmik + */ + +unsigned int snd_ac97_bus_scan_one(struct ac97_controller *adrv, + unsigned int codec_num); + +static inline bool ac97_ids_match(unsigned int id1, unsigned int id2, + unsigned int mask) +{ + return (id1 & mask) == (id2 & mask); +} diff --git a/sound/ac97/bus.c b/sound/ac97/bus.c new file mode 100644 index 000000000..a4d230a19 --- /dev/null +++ b/sound/ac97/bus.c @@ -0,0 +1,526 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 Robert Jarzmik + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "ac97_core.h" + +/* + * Protects ac97_controllers and each ac97_controller structure. + */ +static DEFINE_MUTEX(ac97_controllers_mutex); +static DEFINE_IDR(ac97_adapter_idr); +static LIST_HEAD(ac97_controllers); + +static inline struct ac97_controller* +to_ac97_controller(struct device *ac97_adapter) +{ + return container_of(ac97_adapter, struct ac97_controller, adap); +} + +static int ac97_unbound_ctrl_write(struct ac97_controller *adrv, int slot, + unsigned short reg, unsigned short val) +{ + return -ENODEV; +} + +static int ac97_unbound_ctrl_read(struct ac97_controller *adrv, int slot, + unsigned short reg) +{ + return -ENODEV; +} + +static const struct ac97_controller_ops ac97_unbound_ctrl_ops = { + .write = ac97_unbound_ctrl_write, + .read = ac97_unbound_ctrl_read, +}; + +static struct ac97_controller ac97_unbound_ctrl = { + .ops = &ac97_unbound_ctrl_ops, +}; + +static struct ac97_codec_device * +ac97_codec_find(struct ac97_controller *ac97_ctrl, unsigned int codec_num) +{ + if (codec_num >= AC97_BUS_MAX_CODECS) + return ERR_PTR(-EINVAL); + + return ac97_ctrl->codecs[codec_num]; +} + +static struct device_node * +ac97_of_get_child_device(struct ac97_controller *ac97_ctrl, int idx, + unsigned int vendor_id) +{ + struct device_node *node; + u32 reg; + char compat[] = "ac97,0000,0000"; + + snprintf(compat, sizeof(compat), "ac97,%04x,%04x", + vendor_id >> 16, vendor_id & 0xffff); + + for_each_child_of_node(ac97_ctrl->parent->of_node, node) { + if ((idx != of_property_read_u32(node, "reg", ®)) || + !of_device_is_compatible(node, compat)) + continue; + return node; + } + + return NULL; +} + +static void ac97_codec_release(struct device *dev) +{ + struct ac97_codec_device *adev; + struct ac97_controller *ac97_ctrl; + + adev = to_ac97_device(dev); + ac97_ctrl = adev->ac97_ctrl; + ac97_ctrl->codecs[adev->num] = NULL; + of_node_put(dev->of_node); + kfree(adev); +} + +static int ac97_codec_add(struct ac97_controller *ac97_ctrl, int idx, + unsigned int vendor_id) +{ + struct ac97_codec_device *codec; + int ret; + + codec = kzalloc_obj(*codec); + if (!codec) + return -ENOMEM; + ac97_ctrl->codecs[idx] = codec; + codec->vendor_id = vendor_id; + codec->dev.release = ac97_codec_release; + codec->dev.bus = &ac97_bus_type; + codec->dev.parent = &ac97_ctrl->adap; + codec->num = idx; + codec->ac97_ctrl = ac97_ctrl; + + device_initialize(&codec->dev); + dev_set_name(&codec->dev, "%s:%u", dev_name(ac97_ctrl->parent), idx); + codec->dev.of_node = ac97_of_get_child_device(ac97_ctrl, idx, + vendor_id); + + ret = device_add(&codec->dev); + if (ret) { + put_device(&codec->dev); + return ret; + } + + return 0; +} + +unsigned int snd_ac97_bus_scan_one(struct ac97_controller *adrv, + unsigned int codec_num) +{ + unsigned short vid1, vid2; + int ret; + + ret = adrv->ops->read(adrv, codec_num, AC97_VENDOR_ID1); + vid1 = (ret & 0xffff); + if (ret < 0) + return 0; + + ret = adrv->ops->read(adrv, codec_num, AC97_VENDOR_ID2); + vid2 = (ret & 0xffff); + if (ret < 0) + return 0; + + dev_dbg(&adrv->adap, "%s(codec_num=%u): vendor_id=0x%08x\n", + __func__, codec_num, AC97_ID(vid1, vid2)); + return AC97_ID(vid1, vid2); +} + +static int ac97_bus_scan(struct ac97_controller *ac97_ctrl) +{ + int ret, i; + unsigned int vendor_id; + + for (i = 0; i < AC97_BUS_MAX_CODECS; i++) { + if (ac97_codec_find(ac97_ctrl, i)) + continue; + if (!(ac97_ctrl->slots_available & BIT(i))) + continue; + vendor_id = snd_ac97_bus_scan_one(ac97_ctrl, i); + if (!vendor_id) + continue; + + ret = ac97_codec_add(ac97_ctrl, i, vendor_id); + if (ret < 0) + return ret; + } + return 0; +} + +static int ac97_bus_reset(struct ac97_controller *ac97_ctrl) +{ + ac97_ctrl->ops->reset(ac97_ctrl); + + return 0; +} + +/** + * snd_ac97_codec_driver_register - register an AC97 codec driver + * @drv: AC97 driver codec to register + * + * Register an AC97 codec driver to the ac97 bus driver, aka. the AC97 digital + * controller. + * + * Returns 0 on success or error code + */ +int snd_ac97_codec_driver_register(struct ac97_codec_driver *drv) +{ + drv->driver.bus = &ac97_bus_type; + return driver_register(&drv->driver); +} +EXPORT_SYMBOL_GPL(snd_ac97_codec_driver_register); + +/** + * snd_ac97_codec_driver_unregister - unregister an AC97 codec driver + * @drv: AC97 codec driver to unregister + * + * Unregister a previously registered ac97 codec driver. + */ +void snd_ac97_codec_driver_unregister(struct ac97_codec_driver *drv) +{ + driver_unregister(&drv->driver); +} +EXPORT_SYMBOL_GPL(snd_ac97_codec_driver_unregister); + +static void ac97_ctrl_codecs_unregister(struct ac97_controller *ac97_ctrl) +{ + int i; + + for (i = 0; i < AC97_BUS_MAX_CODECS; i++) + if (ac97_ctrl->codecs[i]) { + ac97_ctrl->codecs[i]->ac97_ctrl = &ac97_unbound_ctrl; + device_unregister(&ac97_ctrl->codecs[i]->dev); + } +} + +static ssize_t cold_reset_store(struct device *dev, + struct device_attribute *attr, const char *buf, + size_t len) +{ + struct ac97_controller *ac97_ctrl; + + guard(mutex)(&ac97_controllers_mutex); + ac97_ctrl = to_ac97_controller(dev); + ac97_ctrl->ops->reset(ac97_ctrl); + return len; +} +static DEVICE_ATTR_WO(cold_reset); + +static ssize_t warm_reset_store(struct device *dev, + struct device_attribute *attr, const char *buf, + size_t len) +{ + struct ac97_controller *ac97_ctrl; + + if (!dev) + return -ENODEV; + + guard(mutex)(&ac97_controllers_mutex); + ac97_ctrl = to_ac97_controller(dev); + ac97_ctrl->ops->warm_reset(ac97_ctrl); + return len; +} +static DEVICE_ATTR_WO(warm_reset); + +static struct attribute *ac97_controller_device_attrs[] = { + &dev_attr_cold_reset.attr, + &dev_attr_warm_reset.attr, + NULL +}; + +static const struct attribute_group ac97_adapter_attr_group = { + .name = "ac97_operations", + .attrs = ac97_controller_device_attrs, +}; + +static const struct attribute_group *ac97_adapter_groups[] = { + &ac97_adapter_attr_group, + NULL, +}; + +static void ac97_del_adapter(struct ac97_controller *ac97_ctrl) +{ + scoped_guard(mutex, &ac97_controllers_mutex) { + ac97_ctrl_codecs_unregister(ac97_ctrl); + list_del(&ac97_ctrl->controllers); + } + + device_unregister(&ac97_ctrl->adap); +} + +static void ac97_adapter_release(struct device *dev) +{ + struct ac97_controller *ac97_ctrl; + + ac97_ctrl = to_ac97_controller(dev); + idr_remove(&ac97_adapter_idr, ac97_ctrl->nr); + dev_dbg(&ac97_ctrl->adap, "adapter unregistered by %s\n", + dev_name(ac97_ctrl->parent)); + kfree(ac97_ctrl); +} + +static const struct device_type ac97_adapter_type = { + .groups = ac97_adapter_groups, + .release = ac97_adapter_release, +}; + +static int ac97_add_adapter(struct ac97_controller *ac97_ctrl) +{ + int ret; + + guard(mutex)(&ac97_controllers_mutex); + ret = idr_alloc(&ac97_adapter_idr, ac97_ctrl, 0, 0, GFP_KERNEL); + ac97_ctrl->nr = ret; + if (ret >= 0) { + dev_set_name(&ac97_ctrl->adap, "ac97-%d", ret); + ac97_ctrl->adap.type = &ac97_adapter_type; + ac97_ctrl->adap.parent = ac97_ctrl->parent; + ret = device_register(&ac97_ctrl->adap); + if (ret) + put_device(&ac97_ctrl->adap); + } else + kfree(ac97_ctrl); + + if (!ret) { + list_add(&ac97_ctrl->controllers, &ac97_controllers); + dev_dbg(&ac97_ctrl->adap, "adapter registered by %s\n", + dev_name(ac97_ctrl->parent)); + } + return ret; +} + +/** + * snd_ac97_controller_register - register an ac97 controller + * @ops: the ac97 bus operations + * @dev: the device providing the ac97 DC function + * @slots_available: mask of the ac97 codecs that can be scanned and probed + * bit0 => codec 0, bit1 => codec 1 ... bit 3 => codec 3 + * + * Register a digital controller which can control up to 4 ac97 codecs. This is + * the controller side of the AC97 AC-link, while the slave side are the codecs. + * + * Returns a valid controller upon success, negative pointer value upon error + */ +struct ac97_controller *snd_ac97_controller_register( + const struct ac97_controller_ops *ops, struct device *dev, + unsigned short slots_available) +{ + struct ac97_controller *ac97_ctrl; + int ret; + + ac97_ctrl = kzalloc_obj(*ac97_ctrl); + if (!ac97_ctrl) + return ERR_PTR(-ENOMEM); + + ac97_ctrl->ops = ops; + ac97_ctrl->slots_available = slots_available; + ac97_ctrl->parent = dev; + ret = ac97_add_adapter(ac97_ctrl); + + if (ret) + return ERR_PTR(ret); + ac97_bus_reset(ac97_ctrl); + ac97_bus_scan(ac97_ctrl); + + return ac97_ctrl; +} +EXPORT_SYMBOL_GPL(snd_ac97_controller_register); + +/** + * snd_ac97_controller_unregister - unregister an ac97 controller + * @ac97_ctrl: the device previously provided to ac97_controller_register() + * + */ +void snd_ac97_controller_unregister(struct ac97_controller *ac97_ctrl) +{ + ac97_del_adapter(ac97_ctrl); +} +EXPORT_SYMBOL_GPL(snd_ac97_controller_unregister); + +static int ac97_pm_runtime_suspend(struct device *dev) +{ + struct ac97_codec_device *codec = to_ac97_device(dev); + int ret = pm_generic_runtime_suspend(dev); + + if (ret == 0 && dev->driver) { + if (pm_runtime_is_irq_safe(dev)) + clk_disable(codec->clk); + else + clk_disable_unprepare(codec->clk); + } + + return ret; +} + +static int ac97_pm_runtime_resume(struct device *dev) +{ + struct ac97_codec_device *codec = to_ac97_device(dev); + int ret; + + if (dev->driver) { + if (pm_runtime_is_irq_safe(dev)) + ret = clk_enable(codec->clk); + else + ret = clk_prepare_enable(codec->clk); + if (ret) + return ret; + } + + return pm_generic_runtime_resume(dev); +} + +static const struct dev_pm_ops ac97_pm = { + .suspend = pm_generic_suspend, + .resume = pm_generic_resume, + .freeze = pm_generic_freeze, + .thaw = pm_generic_thaw, + .poweroff = pm_generic_poweroff, + .restore = pm_generic_restore, + RUNTIME_PM_OPS(ac97_pm_runtime_suspend, ac97_pm_runtime_resume, NULL) +}; + +static int ac97_get_enable_clk(struct ac97_codec_device *adev) +{ + int ret; + + adev->clk = clk_get(&adev->dev, "ac97_clk"); + if (IS_ERR(adev->clk)) + return PTR_ERR(adev->clk); + + ret = clk_prepare_enable(adev->clk); + if (ret) + clk_put(adev->clk); + + return ret; +} + +static void ac97_put_disable_clk(struct ac97_codec_device *adev) +{ + clk_disable_unprepare(adev->clk); + clk_put(adev->clk); +} + +static ssize_t vendor_id_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct ac97_codec_device *codec = to_ac97_device(dev); + + return sysfs_emit(buf, "%08x", codec->vendor_id); +} +static DEVICE_ATTR_RO(vendor_id); + +static struct attribute *ac97_dev_attrs[] = { + &dev_attr_vendor_id.attr, + NULL, +}; +ATTRIBUTE_GROUPS(ac97_dev); + +static int ac97_bus_match(struct device *dev, const struct device_driver *drv) +{ + struct ac97_codec_device *adev = to_ac97_device(dev); + const struct ac97_codec_driver *adrv = to_ac97_driver(drv); + const struct ac97_id *id = adrv->id_table; + int i = 0; + + if (adev->vendor_id == 0x0 || adev->vendor_id == 0xffffffff) + return false; + + do { + if (ac97_ids_match(id[i].id, adev->vendor_id, id[i].mask)) + return true; + } while (id[i++].id); + + return false; +} + +static int ac97_bus_probe(struct device *dev) +{ + struct ac97_codec_device *adev = to_ac97_device(dev); + struct ac97_codec_driver *adrv = to_ac97_driver(dev->driver); + int ret; + + ret = ac97_get_enable_clk(adev); + if (ret) + return ret; + + pm_runtime_get_noresume(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + + ret = adrv->probe(adev); + if (ret == 0) + return 0; + + pm_runtime_disable(dev); + pm_runtime_set_suspended(dev); + pm_runtime_put_noidle(dev); + ac97_put_disable_clk(adev); + + return ret; +} + +static void ac97_bus_remove(struct device *dev) +{ + struct ac97_codec_device *adev = to_ac97_device(dev); + struct ac97_codec_driver *adrv = to_ac97_driver(dev->driver); + int ret; + + ret = pm_runtime_resume_and_get(dev); + if (ret < 0) + return; + + adrv->remove(adev); + pm_runtime_put_noidle(dev); + ac97_put_disable_clk(adev); + + pm_runtime_disable(dev); +} + +const struct bus_type ac97_bus_type = { + .name = "ac97bus", + .dev_groups = ac97_dev_groups, + .match = ac97_bus_match, + .pm = pm_ptr(&ac97_pm), + .probe = ac97_bus_probe, + .remove = ac97_bus_remove, +}; + +static int __init ac97_bus_init(void) +{ + return bus_register(&ac97_bus_type); +} +subsys_initcall(ac97_bus_init); + +static void __exit ac97_bus_exit(void) +{ + bus_unregister(&ac97_bus_type); +} +module_exit(ac97_bus_exit); + +MODULE_DESCRIPTION("AC97 bus interface"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Robert Jarzmik "); diff --git a/sound/ac97/codec.c b/sound/ac97/codec.c new file mode 100644 index 000000000..1c8357ad6 --- /dev/null +++ b/sound/ac97/codec.c @@ -0,0 +1,12 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 Robert Jarzmik + */ + +#include +#include +#include +#include +#include +#include /* For compat_ac97_* */ + diff --git a/sound/ac97/snd_ac97_compat.c b/sound/ac97/snd_ac97_compat.c new file mode 100644 index 000000000..1a89286d1 --- /dev/null +++ b/sound/ac97/snd_ac97_compat.c @@ -0,0 +1,120 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2016 Robert Jarzmik + */ + +#include +#include +#include +#include +#include +#include + +#include "ac97_core.h" + +static void compat_ac97_release(struct device *dev) +{ + kfree(to_ac97_t(dev)); +} + +static void compat_ac97_reset(struct snd_ac97 *ac97) +{ + struct ac97_codec_device *adev = to_ac97_device(ac97->private_data); + struct ac97_controller *actrl = adev->ac97_ctrl; + + if (actrl->ops->reset) + actrl->ops->reset(actrl); +} + +static void compat_ac97_warm_reset(struct snd_ac97 *ac97) +{ + struct ac97_codec_device *adev = to_ac97_device(ac97->private_data); + struct ac97_controller *actrl = adev->ac97_ctrl; + + if (actrl->ops->warm_reset) + actrl->ops->warm_reset(actrl); +} + +static void compat_ac97_write(struct snd_ac97 *ac97, unsigned short reg, + unsigned short val) +{ + struct ac97_codec_device *adev = to_ac97_device(ac97->private_data); + struct ac97_controller *actrl = adev->ac97_ctrl; + + actrl->ops->write(actrl, ac97->num, reg, val); +} + +static unsigned short compat_ac97_read(struct snd_ac97 *ac97, + unsigned short reg) +{ + struct ac97_codec_device *adev = to_ac97_device(ac97->private_data); + struct ac97_controller *actrl = adev->ac97_ctrl; + + return actrl->ops->read(actrl, ac97->num, reg); +} + +static const struct snd_ac97_bus_ops compat_snd_ac97_bus_ops = { + .reset = compat_ac97_reset, + .warm_reset = compat_ac97_warm_reset, + .write = compat_ac97_write, + .read = compat_ac97_read, +}; + +static struct snd_ac97_bus compat_soc_ac97_bus = { + .ops = &compat_snd_ac97_bus_ops, +}; + +struct snd_ac97 *snd_ac97_compat_alloc(struct ac97_codec_device *adev) +{ + struct snd_ac97 *ac97; + int ret; + + ac97 = kzalloc_obj(struct snd_ac97); + if (ac97 == NULL) + return ERR_PTR(-ENOMEM); + + ac97->private_data = adev; + ac97->bus = &compat_soc_ac97_bus; + + ac97->dev.parent = &adev->dev; + ac97->dev.release = compat_ac97_release; + dev_set_name(&ac97->dev, "%s-compat", dev_name(&adev->dev)); + ret = device_register(&ac97->dev); + if (ret) { + put_device(&ac97->dev); + return ERR_PTR(ret); + } + + return ac97; +} +EXPORT_SYMBOL_GPL(snd_ac97_compat_alloc); + +void snd_ac97_compat_release(struct snd_ac97 *ac97) +{ + device_unregister(&ac97->dev); +} +EXPORT_SYMBOL_GPL(snd_ac97_compat_release); + +int snd_ac97_reset(struct snd_ac97 *ac97, bool try_warm, unsigned int id, + unsigned int id_mask) +{ + struct ac97_codec_device *adev = to_ac97_device(ac97->private_data); + struct ac97_controller *actrl = adev->ac97_ctrl; + unsigned int scanned; + + if (try_warm) { + compat_ac97_warm_reset(ac97); + scanned = snd_ac97_bus_scan_one(actrl, adev->num); + if (ac97_ids_match(scanned, adev->vendor_id, id_mask)) + return 1; + } + + compat_ac97_reset(ac97); + compat_ac97_warm_reset(ac97); + scanned = snd_ac97_bus_scan_one(actrl, adev->num); + if (ac97_ids_match(scanned, adev->vendor_id, id_mask)) + return 0; + + return -ENODEV; +} +EXPORT_SYMBOL_GPL(snd_ac97_reset); -- cgit v1.3.1