diff --git a/MAINTAINERS b/MAINTAINERS index cc3cae2e378b..b8e8b362f932 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -24742,7 +24742,9 @@ M: Sudeep Holla L: linux-arm-kernel@lists.infradead.org (moderated for non-subscribers) S: Maintained F: drivers/firmware/smccc/ +F: include/linux/arm-smccc-bus.h F: include/linux/arm-smccc.h +F: include/linux/device-id/arm_smccc.h SECURITY CONTACT M: Security Officers diff --git a/drivers/firmware/smccc/Makefile b/drivers/firmware/smccc/Makefile index 40d19144a860..68bbff1407b8 100644 --- a/drivers/firmware/smccc/Makefile +++ b/drivers/firmware/smccc/Makefile @@ -1,4 +1,4 @@ # SPDX-License-Identifier: GPL-2.0 # -obj-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += smccc.o kvm_guest.o +obj-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += bus.o smccc.o kvm_guest.o obj-$(CONFIG_ARM_SMCCC_SOC_ID) += soc_id.o diff --git a/drivers/firmware/smccc/bus.c b/drivers/firmware/smccc/bus.c new file mode 100644 index 000000000000..0357a7c48af0 --- /dev/null +++ b/drivers/firmware/smccc/bus.c @@ -0,0 +1,158 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2026 Arm Limited + */ + +#include +#include + +static int arm_smccc_bus_match(struct device *dev, + const struct device_driver *drv) +{ + const struct arm_smccc_device_id *id_table; + const struct arm_smccc_device *smccc_dev = to_arm_smccc_device(dev); + + id_table = to_arm_smccc_driver(drv)->id_table; + if (!id_table) + return 0; + + while (id_table->func_id) { + if (smccc_dev->func_id == id_table->func_id) + return 1; + id_table++; + } + + return 0; +} + +static int arm_smccc_bus_probe(struct device *dev) +{ + struct arm_smccc_driver *smccc_drv = to_arm_smccc_driver(dev->driver); + + return smccc_drv->probe(to_arm_smccc_device(dev)); +} + +static void arm_smccc_bus_remove(struct device *dev) +{ + struct arm_smccc_driver *smcc_drv = to_arm_smccc_driver(dev->driver); + + if (smcc_drv->remove) + smcc_drv->remove(to_arm_smccc_device(dev)); +} + +static int arm_smccc_bus_uevent(const struct device *dev, + struct kobj_uevent_env *env) +{ + const struct arm_smccc_device *smccc_dev = to_arm_smccc_device(dev); + + return add_uevent_var(env, "MODALIAS=" ARM_SMCCC_MODULE_PREFIX "f%08X", + smccc_dev->func_id); +} + +static ssize_t modalias_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct arm_smccc_device *smccc_dev = to_arm_smccc_device(dev); + + return sysfs_emit(buf, ARM_SMCCC_MODULE_PREFIX "f%08X\n", + smccc_dev->func_id); +} +static DEVICE_ATTR_RO(modalias); + +static struct attribute *arm_smccc_device_attrs[] = { + &dev_attr_modalias.attr, + NULL, +}; +ATTRIBUTE_GROUPS(arm_smccc_device); + +const struct bus_type arm_smccc_bus_type = { + .name = "arm_smccc", + .match = arm_smccc_bus_match, + .probe = arm_smccc_bus_probe, + .remove = arm_smccc_bus_remove, + .uevent = arm_smccc_bus_uevent, + .dev_groups = arm_smccc_device_groups, +}; +EXPORT_SYMBOL_GPL(arm_smccc_bus_type); + +int arm_smccc_driver_register(struct arm_smccc_driver *driver, + struct module *owner, const char *mod_name) +{ + if (!driver->probe || !driver->id_table) + return -EINVAL; + + driver->driver.bus = &arm_smccc_bus_type; + driver->driver.name = driver->name; + driver->driver.owner = owner; + driver->driver.mod_name = mod_name; + + return driver_register(&driver->driver); +} +EXPORT_SYMBOL_GPL(arm_smccc_driver_register); + +void arm_smccc_driver_unregister(struct arm_smccc_driver *driver) +{ + driver_unregister(&driver->driver); +} +EXPORT_SYMBOL_GPL(arm_smccc_driver_unregister); + +static void arm_smccc_release_device(struct device *dev) +{ + struct arm_smccc_device *smccc_dev = to_arm_smccc_device(dev); + + kfree(smccc_dev); +} + +static struct device *arm_smccc_device_alloc(u32 func_id) +{ + struct arm_smccc_device *smccc_dev; + + smccc_dev = kzalloc_obj(*smccc_dev); + if (!smccc_dev) + return NULL; + + smccc_dev->func_id = func_id; + smccc_dev->dev.bus = &arm_smccc_bus_type; + smccc_dev->dev.release = arm_smccc_release_device; + device_initialize(&smccc_dev->dev); + + return &smccc_dev->dev; +} + +struct arm_smccc_device *arm_smccc_device_register(const char *name, u32 func_id) +{ + int ret; + + if (!name) + return ERR_PTR(-EINVAL); + + struct device *dev __free(put_device) = arm_smccc_device_alloc(func_id); + if (!dev) + return ERR_PTR(-ENOMEM); + + ret = dev_set_name(dev, "%s", name); + if (ret) + return ERR_PTR(ret); + + ret = device_add(dev); + if (ret) + return ERR_PTR(ret); + + return to_arm_smccc_device(no_free_ptr(dev)); +} +EXPORT_SYMBOL_GPL(arm_smccc_device_register); + +void arm_smccc_device_unregister(struct arm_smccc_device *smccc_dev) +{ + if (!smccc_dev) + return; + + device_unregister(&smccc_dev->dev); +} +EXPORT_SYMBOL_GPL(arm_smccc_device_unregister); + +static int __init arm_smccc_bus_init(void) +{ + return bus_register(&arm_smccc_bus_type); +} +subsys_initcall(arm_smccc_bus_init); diff --git a/include/linux/arm-smccc-bus.h b/include/linux/arm-smccc-bus.h new file mode 100644 index 000000000000..05c0c850510e --- /dev/null +++ b/include/linux/arm-smccc-bus.h @@ -0,0 +1,48 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * Copyright (C) 2026 Arm Limited + */ +#ifndef __LINUX_ARM_SMCCC_BUS_H +#define __LINUX_ARM_SMCCC_BUS_H + +#include +#include +#include + +struct arm_smccc_device { + struct device dev; + u32 func_id; +}; + +#define to_arm_smccc_device(d) container_of_const(d, struct arm_smccc_device, dev) + +struct arm_smccc_driver { + struct device_driver driver; + + const char *name; + int (*probe)(struct arm_smccc_device *sdev); + void (*remove)(struct arm_smccc_device *sdev); + const struct arm_smccc_device_id *id_table; +}; + +#define to_arm_smccc_driver(d) \ + container_of_const(d, struct arm_smccc_driver, driver) + +int arm_smccc_driver_register(struct arm_smccc_driver *driver, + struct module *owner, const char *mod_name); +void arm_smccc_driver_unregister(struct arm_smccc_driver *driver); +struct arm_smccc_device *arm_smccc_device_register(const char *name, u32 func_id); +void arm_smccc_device_unregister(struct arm_smccc_device *smcc_dev); + +#define arm_smccc_register(driver) \ + arm_smccc_driver_register(driver, THIS_MODULE, KBUILD_MODNAME) +#define arm_smccc_unregister(driver) \ + arm_smccc_driver_unregister(driver) + +#define module_arm_smccc_driver(__arm_smccc_driver) \ + module_driver(__arm_smccc_driver, arm_smccc_register, \ + arm_smccc_unregister) + +extern const struct bus_type arm_smccc_bus_type; + +#endif /* __LINUX_ARM_SMCCC_BUS_H */ diff --git a/include/linux/device-id/arm_smccc.h b/include/linux/device-id/arm_smccc.h new file mode 100644 index 000000000000..a8579832fc1c --- /dev/null +++ b/include/linux/device-id/arm_smccc.h @@ -0,0 +1,19 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __LINUX_DEVICE_ID_ARM_SMCCC_H +#define __LINUX_DEVICE_ID_ARM_SMCCC_H + +#ifdef __KERNEL__ +#include +#endif + +#define ARM_SMCCC_MODULE_PREFIX "arm_smccc:" + +/** + * struct arm_smccc_device_id - Arm SMCCC bus device identifier + * @func_id: SMCCC function identifier + */ +struct arm_smccc_device_id { + __u32 func_id; +}; + +#endif /* __LINUX_DEVICE_ID_ARM_SMCCC_H */ diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h index a397213bedac..318c4b5c3451 100644 --- a/include/linux/mod_devicetable.h +++ b/include/linux/mod_devicetable.h @@ -16,6 +16,7 @@ #include "device-id/amba.h" #include "device-id/ap.h" #include "device-id/apr.h" +#include "device-id/arm_smccc.h" #include "device-id/auxiliary.h" #include "device-id/bcma.h" #include "device-id/ccw.h" diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c index b4178c42d08f..1492e9fdc7cb 100644 --- a/scripts/mod/devicetable-offsets.c +++ b/scripts/mod/devicetable-offsets.c @@ -254,6 +254,9 @@ int main(void) DEVID(auxiliary_device_id); DEVID_FIELD(auxiliary_device_id, name); + DEVID(arm_smccc_device_id); + DEVID_FIELD(arm_smccc_device_id, func_id); + DEVID(ssam_device_id); DEVID_FIELD(ssam_device_id, match_flags); DEVID_FIELD(ssam_device_id, domain); diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c index 8d36c74dec2d..980d7da456bb 100644 --- a/scripts/mod/file2alias.c +++ b/scripts/mod/file2alias.c @@ -1349,6 +1349,13 @@ static void do_auxiliary_entry(struct module *mod, void *symval) module_alias_printf(mod, false, AUXILIARY_MODULE_PREFIX "%s", *name); } +static void do_arm_smccc_entry(struct module *mod, void *symval) +{ + DEF_FIELD(symval, arm_smccc_device_id, func_id); + + module_alias_printf(mod, false, ARM_SMCCC_MODULE_PREFIX "f%08X", func_id); +} + /* * Looks like: ssam:dNcNtNiNfN * @@ -1519,6 +1526,7 @@ static const struct devtable devtable[] = { {"mhi", SIZE_mhi_device_id, do_mhi_entry}, {"mhi_ep", SIZE_mhi_device_id, do_mhi_ep_entry}, {"auxiliary", SIZE_auxiliary_device_id, do_auxiliary_entry}, + {"arm_smccc", SIZE_arm_smccc_device_id, do_arm_smccc_entry}, {"ssam", SIZE_ssam_device_id, do_ssam_entry}, {"dfl", SIZE_dfl_device_id, do_dfl_entry}, {"ishtp", SIZE_ishtp_device_id, do_ishtp_entry},