diff --git a/drivers/misc/amd-sbi/tsi-core.c b/drivers/misc/amd-sbi/tsi-core.c index 1c6f37f26d94..5c178702c67a 100644 --- a/drivers/misc/amd-sbi/tsi-core.c +++ b/drivers/misc/amd-sbi/tsi-core.c @@ -6,7 +6,11 @@ * Copyright (C) 2026 Advanced Micro Devices, Inc. */ +#include +#include #include +#include +#include #include "tsi-core.h" static inline struct sbtsi_i3c_priv *to_sbtsi_i3c_priv(struct sbtsi_data *data) @@ -14,6 +18,17 @@ static inline struct sbtsi_i3c_priv *to_sbtsi_i3c_priv(struct sbtsi_data *data) return container_of(data, struct sbtsi_i3c_priv, data); } +void sbtsi_data_release(struct kref *kref) +{ + struct sbtsi_data *data = container_of(kref, struct sbtsi_data, kref); + + mutex_destroy(&data->lock); + if (data->is_i3c) + kfree(to_sbtsi_i3c_priv(data)); + else + kfree(data); +} + /* I2C transfer function */ static int sbtsi_i2c_xfer(struct sbtsi_data *data, u8 reg, u8 *val, bool is_read) { @@ -77,7 +92,116 @@ int sbtsi_xfer(struct sbtsi_data *data, u8 reg, u8 *val, bool is_read) if (data->is_i3c) return is_read ? sbtsi_i3c_read(data, reg, val) : sbtsi_i3c_write(data, reg, *val); - return sbtsi_i2c_xfer(data, reg, val, is_read); } EXPORT_SYMBOL_GPL(sbtsi_xfer); + +/* + * The mutex protects against concurrent register transfers to the device + * over the shared bus. + */ +static int sbtsi_xfer_ioctl(struct sbtsi_data *data, u8 reg, u8 *val, bool is_read) +{ + guard(sbtsi)(data); + + if (data->detached) + return -ENODEV; + + return sbtsi_xfer(data, reg, val, is_read); +} + +static int apml_tsi_reg_xfer(struct sbtsi_data *data, + struct apml_tsi_xfer_msg __user *arg) +{ + struct apml_tsi_xfer_msg msg = { 0 }; + int ret; + + if (copy_from_user(&msg, arg, sizeof(struct apml_tsi_xfer_msg))) + return -EFAULT; + + /* + * rflag is a boolean direction flag (0 = write, 1 = read). Reject + * any other value so the upper values stay reserved for future + * extensions instead of being silently treated as a read. + */ + if (msg.pad || msg.rflag > 1) + return -EINVAL; + + ret = sbtsi_xfer_ioctl(data, msg.reg_addr, &msg.data_in_out, msg.rflag); + + if (msg.rflag && !ret) { + if (copy_to_user(arg, &msg, sizeof(struct apml_tsi_xfer_msg))) + return -EFAULT; + } + return ret; +} + +static int sbtsi_open(struct inode *inode, struct file *fp) +{ + struct sbtsi_data *data; + + data = container_of(fp->private_data, struct sbtsi_data, sbtsi_misc_dev); + scoped_guard(sbtsi, data) { + if (data->detached) + return -ENODEV; + } + + kref_get(&data->kref); + + return 0; +} + +static int sbtsi_release(struct inode *inode, struct file *fp) +{ + struct sbtsi_data *data; + + data = container_of(fp->private_data, struct sbtsi_data, sbtsi_misc_dev); + kref_put(&data->kref, sbtsi_data_release); + return 0; +} + +static long sbtsi_ioctl(struct file *fp, unsigned int cmd, unsigned long arg) +{ + void __user *argp = (void __user *)arg; + struct sbtsi_data *data; + + data = container_of(fp->private_data, struct sbtsi_data, sbtsi_misc_dev); + switch (cmd) { + case SBTSI_IOCTL_REG_XFER_CMD: + return apml_tsi_reg_xfer(data, argp); + default: + return -ENOTTY; + } +} + +static const struct file_operations sbtsi_fops = { + .owner = THIS_MODULE, + .open = sbtsi_open, + .release = sbtsi_release, + .unlocked_ioctl = sbtsi_ioctl, + .compat_ioctl = compat_ptr_ioctl, +}; + +int create_misc_tsi_device(struct sbtsi_data *data, struct device *dev) +{ + int ret; + + data->sbtsi_misc_dev.name = devm_kasprintf(dev, GFP_KERNEL, + "sbtsi-%x", data->dev_addr); + if (!data->sbtsi_misc_dev.name) + return -ENOMEM; + data->sbtsi_misc_dev.minor = MISC_DYNAMIC_MINOR; + data->sbtsi_misc_dev.fops = &sbtsi_fops; + data->sbtsi_misc_dev.parent = dev; + data->sbtsi_misc_dev.nodename = devm_kasprintf(dev, GFP_KERNEL, + "sbtsi-%x", data->dev_addr); + if (!data->sbtsi_misc_dev.nodename) + return -ENOMEM; + data->sbtsi_misc_dev.mode = 0600; + + ret = misc_register(&data->sbtsi_misc_dev); + if (ret) + return ret; + + return 0; +} diff --git a/drivers/misc/amd-sbi/tsi-core.h b/drivers/misc/amd-sbi/tsi-core.h index 7e8c0e7c3bcf..4cf55c46230e 100644 --- a/drivers/misc/amd-sbi/tsi-core.h +++ b/drivers/misc/amd-sbi/tsi-core.h @@ -23,4 +23,7 @@ struct sbtsi_i3c_priv { u8 rx __aligned(ARCH_DMA_MINALIGN); }; +int create_misc_tsi_device(struct sbtsi_data *data, struct device *dev); + +void sbtsi_data_release(struct kref *kref); #endif /* _LINUX_TSI_CORE_H_ */ diff --git a/drivers/misc/amd-sbi/tsi.c b/drivers/misc/amd-sbi/tsi.c index 1530f440a020..f06f417f451c 100644 --- a/drivers/misc/amd-sbi/tsi.c +++ b/drivers/misc/amd-sbi/tsi.c @@ -42,6 +42,23 @@ static void sbtsi_unregister_hwmon_adev(void *_adev) auxiliary_device_uninit(adev); } +static void sbtsi_misc_unregister(void *arg) +{ + struct sbtsi_data *data = arg; + + misc_deregister(&data->sbtsi_misc_dev); + + guard(sbtsi)(data); + data->detached = true; +} + +static void sbtsi_driver_unref(void *arg) +{ + struct sbtsi_data *data = arg; + + kref_put(&data->kref, sbtsi_data_release); +} + /* * Create and publish an auxiliary device. The hwmon driver in * drivers/hwmon/sbtsi_temp.c binds to this device. @@ -84,6 +101,13 @@ static int sbtsi_probe_common(struct device *dev, struct sbtsi_data *data) u8 val; int err; + mutex_init(&data->lock); + kref_init(&data->kref); + + err = devm_add_action_or_reset(dev, sbtsi_driver_unref, data); + if (err) + return err; + err = sbtsi_xfer(data, SBTSI_REG_CONFIG, &val, true); if (err) return err; @@ -92,7 +116,15 @@ static int sbtsi_probe_common(struct device *dev, struct sbtsi_data *data) data->read_order = FIELD_GET(BIT(SBTSI_CONFIG_READ_ORDER_SHIFT), val); dev_set_drvdata(dev, data); - return sbtsi_create_hwmon_adev(dev, data->dev_addr); + err = sbtsi_create_hwmon_adev(dev, data->dev_addr); + if (err < 0) + return err; + + err = create_misc_tsi_device(data, dev); + if (err) + return err; + + return devm_add_action_or_reset(dev, sbtsi_misc_unregister, data); } static int sbtsi_i2c_probe(struct i2c_client *client) @@ -100,7 +132,7 @@ static int sbtsi_i2c_probe(struct i2c_client *client) struct device *dev = &client->dev; struct sbtsi_data *data; - data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + data = kzalloc_obj(*data); if (!data) return -ENOMEM; @@ -158,7 +190,7 @@ static int sbtsi_i3c_probe(struct i3c_device *i3cdev) if (I3C_PID_INSTANCE_ID(devinfo.pid) != 0) return -ENXIO; - i3c_priv = devm_kzalloc(dev, sizeof(*i3c_priv), GFP_KERNEL); + i3c_priv = kzalloc_obj(*i3c_priv); if (!i3c_priv) return -ENOMEM; diff --git a/include/linux/misc/tsi.h b/include/linux/misc/tsi.h index 0bdd9d923f92..5273c44688f0 100644 --- a/include/linux/misc/tsi.h +++ b/include/linux/misc/tsi.h @@ -8,30 +8,46 @@ #ifndef _LINUX_MISC_TSI_H_ #define _LINUX_MISC_TSI_H_ +#include #include #include +#include +#include +#include #include /** * struct sbtsi_data - driver private data for an AMD SB-TSI device * @client: underlying I2C client * @i3cdev: underlying I3C device (when using I3C bus) + * @sbtsi_misc_dev: miscdevice exposing ioctl interface at /dev/sbtsi- + * @lock: mutex protecting concurrent access to the device + * @kref: reference count; keeps @sbtsi_data alive while misc fds are open * @dev_addr: I2C/I3C device address, used as the auxiliary device instance id + * and name the misc device node * @ext_range_mode: sensor uses extended temperature range * @read_order: if set, decimal part must be read before integer part * @is_i3c: true when the device is accessed over I3C + * @detached: set on driver unbind; open/ioctl return -ENODEV afterward */ struct sbtsi_data { union { struct i2c_client *client; struct i3c_device *i3cdev; }; + struct miscdevice sbtsi_misc_dev; + struct mutex lock; /* protects concurrent access to the device */ + struct kref kref; u8 dev_addr; bool ext_range_mode; bool read_order; bool is_i3c; + bool detached; }; +DEFINE_GUARD(sbtsi, struct sbtsi_data *, mutex_lock(&_T->lock), + mutex_unlock(&_T->lock)) + /* * Name of the auxiliary device published on the auxiliary bus by the core * driver. The full device name is "amd-sbtsi.temp-sensor.". where diff --git a/include/uapi/misc/amd-apml.h b/include/uapi/misc/amd-apml.h index 745b3338fc06..8a85f79b0938 100644 --- a/include/uapi/misc/amd-apml.h +++ b/include/uapi/misc/amd-apml.h @@ -73,6 +73,13 @@ struct apml_reg_xfer_msg { __u8 rflag; }; +struct apml_tsi_xfer_msg { + __u8 reg_addr; /* TSI register address offset */ + __u8 data_in_out; /* Register data for read/write */ + __u8 rflag; /* Register read or write */ + __u8 pad; /* Explicit padding */ +}; + /* * AMD sideband interface base IOCTL */ @@ -149,4 +156,20 @@ struct apml_reg_xfer_msg { */ #define SBRMI_IOCTL_REG_XFER_CMD _IOWR(SB_BASE_IOCTL_NR, 3, struct apml_reg_xfer_msg) +/** + * DOC: SBTSI_IOCTL_REG_XFER_CMD + * + * @Parameters + * + * @struct apml_tsi_xfer_msg + * Pointer to the &struct apml_tsi_xfer_msg that will contain the protocol + * information + * + * @Description + * IOCTL command for APML TSI messages using generic _IOWR + * The IOCTL provides userspace access to AMD sideband TSI register xfer protocol + * - TSI protocol to read/write temperature sensor registers + */ +#define SBTSI_IOCTL_REG_XFER_CMD _IOWR(SB_BASE_IOCTL_NR, 4, struct apml_tsi_xfer_msg) + #endif /*_AMD_APML_H_*/