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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/misc/pvpanic/pvpanic.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/misc/pvpanic/pvpanic.c')
| -rw-r--r-- | drivers/misc/pvpanic/pvpanic.c | 231 |
1 files changed, 231 insertions, 0 deletions
diff --git a/drivers/misc/pvpanic/pvpanic.c b/drivers/misc/pvpanic/pvpanic.c new file mode 100644 index 000000000..b57d773f6 --- /dev/null +++ b/drivers/misc/pvpanic/pvpanic.c @@ -0,0 +1,231 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Pvpanic Device Support + * + * Copyright (C) 2013 Fujitsu. + * Copyright (C) 2018 ZTE. + * Copyright (C) 2021 Oracle. + */ + +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/gfp_types.h> +#include <linux/io.h> +#include <linux/kexec.h> +#include <linux/kstrtox.h> +#include <linux/limits.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/panic_notifier.h> +#include <linux/platform_device.h> +#include <linux/reboot.h> +#include <linux/spinlock.h> +#include <linux/sysfs.h> +#include <linux/types.h> + +#include <uapi/misc/pvpanic.h> + +#include "pvpanic.h" + +MODULE_AUTHOR("Mihai Carabas <mihai.carabas@oracle.com>"); +MODULE_DESCRIPTION("pvpanic device driver"); +MODULE_LICENSE("GPL"); + +struct pvpanic_instance { + void __iomem *base; + unsigned int capability; + unsigned int events; + struct sys_off_handler *sys_off; + struct list_head list; +}; + +static struct list_head pvpanic_list; +static spinlock_t pvpanic_lock; + +static void +pvpanic_send_event(unsigned int event) +{ + struct pvpanic_instance *pi_cur; + + if (!spin_trylock(&pvpanic_lock)) + return; + + list_for_each_entry(pi_cur, &pvpanic_list, list) { + if (event & pi_cur->capability & pi_cur->events) + iowrite8(event, pi_cur->base); + } + spin_unlock(&pvpanic_lock); +} + +static int +pvpanic_panic_notify(struct notifier_block *nb, unsigned long code, void *unused) +{ + unsigned int event = PVPANIC_PANICKED; + + if (kexec_crash_loaded()) + event = PVPANIC_CRASH_LOADED; + + pvpanic_send_event(event); + + return NOTIFY_DONE; +} + +/* + * Call our notifier very early on panic, deferring the + * action taken to the hypervisor. + */ +static struct notifier_block pvpanic_panic_nb = { + .notifier_call = pvpanic_panic_notify, + .priority = INT_MAX, +}; + +static int pvpanic_sys_off(struct sys_off_data *data) +{ + pvpanic_send_event(PVPANIC_SHUTDOWN); + + return NOTIFY_DONE; +} + +static void pvpanic_synchronize_sys_off_handler(struct device *dev, struct pvpanic_instance *pi) +{ + /* The kernel core has logic to fall back to system halt if no + * sys_off_handler is registered. + * When the pvpanic sys_off_handler is disabled via sysfs the kernel + * should use that fallback logic, so the handler needs to be unregistered. + */ + + struct sys_off_handler *sys_off; + + if (!(pi->events & PVPANIC_SHUTDOWN) == !pi->sys_off) + return; + + if (!pi->sys_off) { + sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, SYS_OFF_PRIO_LOW, + pvpanic_sys_off, NULL); + if (IS_ERR(sys_off)) + dev_warn(dev, "Could not register sys_off_handler: %pe\n", sys_off); + else + pi->sys_off = sys_off; + } else { + unregister_sys_off_handler(pi->sys_off); + pi->sys_off = NULL; + } +} + +static void pvpanic_remove(void *param) +{ + struct pvpanic_instance *pi_cur, *pi_next; + struct pvpanic_instance *pi = param; + + spin_lock(&pvpanic_lock); + list_for_each_entry_safe(pi_cur, pi_next, &pvpanic_list, list) { + if (pi_cur == pi) { + list_del(&pi_cur->list); + break; + } + } + spin_unlock(&pvpanic_lock); + + unregister_sys_off_handler(pi->sys_off); +} + +static ssize_t capability_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct pvpanic_instance *pi = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%x\n", pi->capability); +} +static DEVICE_ATTR_RO(capability); + +static ssize_t events_show(struct device *dev, struct device_attribute *attr, char *buf) +{ + struct pvpanic_instance *pi = dev_get_drvdata(dev); + + return sysfs_emit(buf, "%x\n", pi->events); +} + +static ssize_t events_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t count) +{ + struct pvpanic_instance *pi = dev_get_drvdata(dev); + unsigned int tmp; + int err; + + err = kstrtouint(buf, 16, &tmp); + if (err) + return err; + + if ((tmp & pi->capability) != tmp) + return -EINVAL; + + pi->events = tmp; + pvpanic_synchronize_sys_off_handler(dev, pi); + + return count; +} +static DEVICE_ATTR_RW(events); + +static struct attribute *pvpanic_dev_attrs[] = { + &dev_attr_capability.attr, + &dev_attr_events.attr, + NULL +}; + +static const struct attribute_group pvpanic_dev_group = { + .attrs = pvpanic_dev_attrs, +}; + +const struct attribute_group *pvpanic_dev_groups[] = { + &pvpanic_dev_group, + NULL +}; +EXPORT_SYMBOL_GPL(pvpanic_dev_groups); + +int devm_pvpanic_probe(struct device *dev, void __iomem *base) +{ + struct pvpanic_instance *pi; + + if (!base) + return -EINVAL; + + pi = devm_kmalloc(dev, sizeof(*pi), GFP_KERNEL); + if (!pi) + return -ENOMEM; + + pi->base = base; + pi->capability = PVPANIC_PANICKED | PVPANIC_CRASH_LOADED | PVPANIC_SHUTDOWN; + + /* initlize capability by RDPT */ + pi->capability &= ioread8(base); + pi->events = pi->capability; + + pi->sys_off = NULL; + pvpanic_synchronize_sys_off_handler(dev, pi); + + spin_lock(&pvpanic_lock); + list_add(&pi->list, &pvpanic_list); + spin_unlock(&pvpanic_lock); + + dev_set_drvdata(dev, pi); + + return devm_add_action_or_reset(dev, pvpanic_remove, pi); +} +EXPORT_SYMBOL_GPL(devm_pvpanic_probe); + +static int pvpanic_init(void) +{ + INIT_LIST_HEAD(&pvpanic_list); + spin_lock_init(&pvpanic_lock); + + atomic_notifier_chain_register(&panic_notifier_list, &pvpanic_panic_nb); + + return 0; +} +module_init(pvpanic_init); + +static void pvpanic_exit(void) +{ + atomic_notifier_chain_unregister(&panic_notifier_list, &pvpanic_panic_nb); + +} +module_exit(pvpanic_exit); |
