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* kernel/reboot: Add device to sys_off_handlerBenjamin Bara2023-07-281-0/+3
| | | | | | | | | | | If the dev is known (e.g. a devm-based sys_off_handler is used), it can be passed to the handler's callback to have it available there. Otherwise, cb_data might be set to the dev in most of the cases. Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Benjamin Bara <benjamin.bara@skidata.com> Link: https://lore.kernel.org/r/20230327-tegra-pmic-reboot-v7-3-18699d5dcd76@skidata.com Signed-off-by: Lee Jones <lee@kernel.org>
* kernel/reboot: emergency_restart: Set correct system_stateBenjamin Bara2023-07-281-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | As the emergency restart does not call kernel_restart_prepare(), the system_state stays in SYSTEM_RUNNING. Since bae1d3a05a8b, this hinders i2c_in_atomic_xfer_mode() from becoming active, and therefore might lead to avoidable warnings in the restart handlers, e.g.: [ 12.667612] WARNING: CPU: 1 PID: 1 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x33c/0x6b0 [ 12.676926] Voluntary context switch within RCU read-side critical section! ... [ 12.742376] schedule_timeout from wait_for_completion_timeout+0x90/0x114 [ 12.749179] wait_for_completion_timeout from tegra_i2c_wait_completion+0x40/0x70 ... [ 12.994527] atomic_notifier_call_chain from machine_restart+0x34/0x58 [ 13.001050] machine_restart from panic+0x2a8/0x32c Avoid these by setting the correct system_state. Fixes: bae1d3a05a8b ("i2c: core: remove use of in_atomic()") Cc: stable@vger.kernel.org # v5.2+ Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Tested-by: Nishanth Menon <nm@ti.com> Signed-off-by: Benjamin Bara <benjamin.bara@skidata.com> Link: https://lore.kernel.org/r/20230327-tegra-pmic-reboot-v7-1-18699d5dcd76@skidata.com Signed-off-by: Lee Jones <lee@kernel.org>
* kernel/reboot: Add SYS_OFF_MODE_RESTART_PREPARE modeKai-Heng Feng2022-10-041-0/+17
| | | | | | | | | | | Add SYS_OFF_MODE_RESTART_PREPARE callbacks to be invoked before a system restart. Suggested-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Reviewed-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* Merge branch 'rework/kthreads' into for-linusPetr Mladek2022-06-231-15/+1
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| * Revert "printk: add functions to prefer direct printing"Petr Mladek2022-06-231-13/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit 2bb2b7b57f81255c13f4395ea911d6bdc70c9fe2. The testing of 5.19 release candidates revealed missing synchronization between early and regular console functionality. It would be possible to start the console kthreads later as a workaround. But it is clear that console lock serialized console drivers between each other. It opens a big area of possible problems that were not considered by people involved in the development and review. printk() is crucial for debugging kernel issues and console output is very important part of it. The number of consoles is huge and a proper review would take some time. As a result it need to be reverted for 5.19. Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alley Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220623145157.21938-7-pmladek@suse.com
| * Revert "printk: Wait for the global console lock when the system is going down"Petr Mladek2022-06-231-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit b87f02307d3cfbda768520f0687c51ca77e14fc3. The testing of 5.19 release candidates revealed missing synchronization between early and regular console functionality. It would be possible to start the console kthreads later as a workaround. But it is clear that console lock serialized console drivers between each other. It opens a big area of possible problems that were not considered by people involved in the development and review. printk() is crucial for debugging kernel issues and console output is very important part of it. The number of consoles is huge and a proper review would take some time. As a result it need to be reverted for 5.19. Link: https://lore.kernel.org/r/YrBdjVwBOVgLfHyb@alley Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220623145157.21938-2-pmladek@suse.com
* | Merge tag 'printk-for-5.19-rc3' of ↵Linus Torvalds2022-06-171-0/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux Pull printk fixes from Petr Mladek: "Make the global console_sem available for CPU that is handling panic() or shutdown. This is an old problem when an existing console lock owner might block console output, but it became more visible with the kthreads" * tag 'printk-for-5.19-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: printk: Wait for the global console lock when the system is going down printk: Block console kthreads when direct printing will be required
| * | Merge branch 'rework/kthreads' into for-linusPetr Mladek2022-06-171-0/+2
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| | * printk: Wait for the global console lock when the system is going downPetr Mladek2022-06-151-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are reports that the console kthreads block the global console lock when the system is going down, for example, reboot, panic. First part of the solution was to block kthreads in these problematic system states so they stopped handling newly added messages. Second part of the solution is to wait when for the kthreads when they are actively printing. It solves the problem when a message was printed before the system entered the problematic state and the kthreads managed to step in. A busy waiting has to be used because panic() can be called in any context and in an unknown state of the scheduler. There must be a timeout because the kthread might get stuck or sleeping and never release the lock. The timeout 10s is an arbitrary value inspired by the softlockup timeout. Link: https://lore.kernel.org/r/20220610205038.GA3050413@paulmck-ThinkPad-P17-Gen-1 Link: https://lore.kernel.org/r/CAMdYzYpF4FNTBPZsEFeWRuEwSies36QM_As8osPWZSr2q-viEA@mail.gmail.com Signed-off-by: Petr Mladek <pmladek@suse.com> Tested-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20220615162805.27962-3-pmladek@suse.com
* | | kernel/reboot: Fix powering off using a non-syscall code pathsDmitry Osipenko2022-06-071-20/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are other methods of powering off machine than the reboot syscall. Previously we missed to cover those methods and it created power-off regression for some machines, like the PowerPC e500. Fix this problem by moving the legacy sys-off handler registration to the latest phase of power-off process and making the kernel_can_power_off() check the legacy pm_power_off presence. Tested-by: Michael Ellerman <mpe@ellerman.id.au> # ppce500 Reported-by: Michael Ellerman <mpe@ellerman.id.au> # ppce500 Fixes: da007f171fc9 ("kernel/reboot: Change registration order of legacy power-off handler") Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | | kernel/reboot: Use static handler for register_platform_power_off()Dmitry Osipenko2022-06-021-6/+37
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | The register_platform_power_off() fails on m68k platform due to the memory allocation error that happens at a very early boot time when memory allocator isn't available yet. Fix it by using a static sys-off handler for the platform-level power-off handlers. Fixes: f0f7e5265b3b ("m68k: Switch to new sys-off handler API") Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | Merge tag 'pm-5.19-rc1-2' of ↵Linus Torvalds2022-05-301-7/+341
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management updates from Rafael Wysocki: "These update the ARM cpufreq drivers and fix up the CPPC cpufreq driver after recent changes, update the OPP code and PM documentation and add power sequences support to the system reboot and power off code. Specifics: - Add Tegra234 cpufreq support (Sumit Gupta) - Clean up and enhance the Mediatek cpufreq driver (Wan Jiabing, Rex-BC Chen, and Jia-Wei Chang) - Fix up the CPPC cpufreq driver after recent changes (Zheng Bin, Pierre Gondois) - Minor update to dt-binding for Qcom's opp-v2-kryo-cpu (Yassine Oudjana) - Use list iterator only inside the list_for_each_entry loop (Xiaomeng Tong, and Jakob Koschel) - New APIs related to finding OPP based on interconnect bandwidth (Krzysztof Kozlowski) - Fix the missing of_node_put() in _bandwidth_supported() (Dan Carpenter) - Cleanups (Krzysztof Kozlowski, and Viresh Kumar) - Add Out of Band mode description to the intel-speed-select utility documentation (Srinivas Pandruvada) - Add power sequences support to the system reboot and power off code and make related platform-specific changes for multiple platforms (Dmitry Osipenko, Geert Uytterhoeven)" * tag 'pm-5.19-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (60 commits) cpufreq: CPPC: Fix unused-function warning cpufreq: CPPC: Fix build error without CONFIG_ACPI_CPPC_CPUFREQ_FIE Documentation: admin-guide: PM: Add Out of Band mode kernel/reboot: Change registration order of legacy power-off handler m68k: virt: Switch to new sys-off handler API kernel/reboot: Add devm_register_restart_handler() kernel/reboot: Add devm_register_power_off_handler() soc/tegra: pmc: Use sys-off handler API to power off Nexus 7 properly reboot: Remove pm_power_off_prepare() regulator: pfuze100: Use devm_register_sys_off_handler() ACPI: power: Switch to sys-off handler API memory: emif: Use kernel_can_power_off() mips: Use do_kernel_power_off() ia64: Use do_kernel_power_off() x86: Use do_kernel_power_off() sh: Use do_kernel_power_off() m68k: Switch to new sys-off handler API powerpc: Use do_kernel_power_off() xen/x86: Use do_kernel_power_off() parisc: Use do_kernel_power_off() ...
| * | kernel/reboot: Change registration order of legacy power-off handlerDmitry Osipenko2022-05-251-16/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We're unconditionally registering sys-off handler for the legacy pm_power_off() callback, this causes problem for platforms that don't use power-off handlers at all and should be halted. Now reboot syscall assumes that there is a power-off handler installed and tries to power off system instead of halting it. To fix the trouble, move the handler's registration to the reboot syscall and check the pm_power_off() presence. Fixes: 0e2110d2e910 ("kernel/reboot: Add kernel_can_power_off()") Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | kernel/reboot: Add devm_register_restart_handler()Dmitry Osipenko2022-05-191-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add devm_register_restart_handler() helper that registers sys-off handler using restart mode and with a default priority. Most drivers will want to register restart handler with a default priority, so this helper will reduce the boilerplate code and make code easier to read and follow. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | kernel/reboot: Add devm_register_power_off_handler()Dmitry Osipenko2022-05-191-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add devm_register_power_off_handler() helper that registers sys-off handler using power-off mode and with a default priority. Most drivers will want to register power-off handler with a default priority, so this helper will reduce the boilerplate code and make code easier to read and follow. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | reboot: Remove pm_power_off_prepare()Dmitry Osipenko2022-05-191-19/+0
| | | | | | | | | | | | | | | | | | | | | | | | All pm_power_off_prepare() users were converted to sys-off handler API. Remove the obsolete global callback variable. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | kernel/reboot: Add register_platform_power_off()Dmitry Osipenko2022-05-191-0/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add platform-level registration helpers that will ease transition of the arch/platform power-off callbacks to the new sys-off based API, allowing us to remove the global pm_power_off variable in the future. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | kernel/reboot: Add kernel_can_power_off()Dmitry Osipenko2022-05-191-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add kernel_can_power_off() helper that replaces open-coded checks of the global pm_power_off variable. This is a necessary step towards supporting chained power-off handlers. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | kernel/reboot: Add stub for pm_power_offDmitry Osipenko2022-05-191-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add weak stub for the global pm_power_off callback variable. This will allow us to remove pm_power_off definitions from arch/ code and transition to the new sys-off based API that will replace the global variable. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | kernel/reboot: Add do_kernel_power_off()Dmitry Osipenko2022-05-191-0/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add do_kernel_power_off() helper that will remove open-coded pm_power_off invocations from the architecture code. This is the first step on the way to remove the global pm_power_off variable, which will allow us to implement consistent power-off chaining support. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | kernel/reboot: Wrap legacy power-off callbacks into sys-off handlersDmitry Osipenko2022-05-191-2/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | Wrap legacy power-off callbacks into sys-off handlers in order to support co-existence of both legacy and new callbacks while we're in process of upgrading legacy callbacks to the new API. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| * | kernel/reboot: Introduce sys-off handler APIDmitry Osipenko2022-05-191-0/+182
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to support power-off chaining we need to get rid of the global pm_* variables, replacing them with the new kernel API functions that support chaining. Introduce new generic sys-off handler API that brings the following features: 1. Power-off and restart handlers are registered using same API function that supports chaining, hence all power-off and restart modes will support chaining using this unified function. 2. Prevents notifier priority collisions by disallowing registration of multiple handlers at the non-default priority level. 3. Supports passing opaque user argument to callback, which allows us to remove global variables from drivers. This patch adds support of the following sys-off modes: - SYS_OFF_MODE_POWER_OFF_PREPARE that replaces global pm_power_off_prepare variable and provides chaining support for power-off-prepare handlers. - SYS_OFF_MODE_POWER_OFF that replaces global pm_power_off variable and provides chaining support for power-off handlers. - SYS_OFF_MODE_RESTART that provides a better restart API, removing a need from drivers to have a global scratch variable by utilizing the opaque callback argument. Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | | Merge tag 'sysctl-5.19-rc1' of ↵Linus Torvalds2022-05-261-2/+32
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux Pull sysctl updates from Luis Chamberlain: "For two kernel releases now kernel/sysctl.c has been being cleaned up slowly, since the tables were grossly long, sprinkled with tons of #ifdefs and all this caused merge conflicts with one susbystem or another. This tree was put together to help try to avoid conflicts with these cleanups going on different trees at time. So nothing exciting on this pull request, just cleanups. Thanks a lot to the Uniontech and Huawei folks for doing some of this nasty work" * tag 'sysctl-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (28 commits) sched: Fix build warning without CONFIG_SYSCTL reboot: Fix build warning without CONFIG_SYSCTL kernel/kexec_core: move kexec_core sysctls into its own file sysctl: minor cleanup in new_dir() ftrace: fix building with SYSCTL=y but DYNAMIC_FTRACE=n fs/proc: Introduce list_for_each_table_entry for proc sysctl mm: fix unused variable kernel warning when SYSCTL=n latencytop: move sysctl to its own file ftrace: fix building with SYSCTL=n but DYNAMIC_FTRACE=y ftrace: Fix build warning ftrace: move sysctl_ftrace_enabled to ftrace.c kernel/do_mount_initrd: move real_root_dev sysctls to its own file kernel/delayacct: move delayacct sysctls to its own file kernel/acct: move acct sysctls to its own file kernel/panic: move panic sysctls to its own file kernel/lockdep: move lockdep sysctls to its own file mm: move page-writeback sysctls to their own file mm: move oom_kill sysctls to their own file kernel/reboot: move reboot sysctls to its own file sched: Move energy_aware sysctls to topology.c ...
| * | reboot: Fix build warning without CONFIG_SYSCTLYueHaibing2022-05-091-27/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If CONFIG_SYSCTL is n, build warn: kernel/reboot.c:443:20: error: ‘kernel_reboot_sysctls_init’ defined but not used [-Werror=unused-function] static void __init kernel_reboot_sysctls_init(void) ^~~~~~~~~~~~~~~~~~~~~~~~~~ Move kernel_reboot_sysctls_init() to #ifdef block to fix this. Fixes: 06d177662fb8 ("kernel/reboot: move reboot sysctls to its own file") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
| * | kernel/reboot: move reboot sysctls to its own filetangmeng2022-04-061-2/+32
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kernel/sysctl.c is a kitchen sink where everyone leaves their dirty dishes, this makes it very difficult to maintain. To help with this maintenance let's start by moving sysctls to places where they actually belong. The proc sysctl maintainers do not want to know what sysctl knobs you wish to add for your own piece of code, we just care about the core logic. All filesystem syctls now get reviewed by fs folks. This commit follows the commit of fs, move the poweroff_cmd and ctrl-alt-del sysctls to its own file, kernel/reboot.c. Signed-off-by: tangmeng <tangmeng@uniontech.com> Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
* / printk: add functions to prefer direct printingJohn Ogness2022-04-221-1/+13
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Once kthread printing is available, console printing will no longer occur in the context of the printk caller. However, there are some special contexts where it is desirable for the printk caller to directly print out kernel messages. Using pr_flush() to wait for threaded printers is only possible if the caller is in a sleepable context and the kthreads are active. That is not always the case. Introduce printk_prefer_direct_enter() and printk_prefer_direct_exit() functions to explicitly (and globally) activate/deactivate preferred direct console printing. The term "direct console printing" refers to printing to all enabled consoles from the context of the printk caller. The term "prefer" is used because this type of printing is only best effort. If the console is currently locked or other printers are already actively printing, the printk caller will need to rely on the other contexts to handle the printing. This preferred direct printing is how all printing has been handled until now (unless it was explicitly deferred). When kthread printing is introduced, there may be some unanticipated problems due to kthreads being unable to flush important messages. In order to minimize such risks, preferred direct printing is activated for the primary important messages when the system experiences general types of major errors. These are: - emergency reboot/shutdown - cpu and rcu stalls - hard and soft lockups - hung tasks - warn - sysrq Note that since kthread printing does not yet exist, no behavior changes result from this commit. This is only implementing the counter and marking the various places where preferred direct printing is active. Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> # for RCU Signed-off-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20220421212250.565456-13-john.ogness@linutronix.de
* Merge branch 'for-linus' of ↵Linus Torvalds2021-11-121-0/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input Pull input updates from Dmitry Torokhov: "Just one new driver (Cypress StreetFighter touchkey), and no input core changes this time. Plus various fixes and enhancements to existing drivers" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (54 commits) Input: iforce - fix control-message timeout Input: wacom_i2c - use macros for the bit masks Input: ili210x - reduce sample period to 15ms Input: ili210x - improve polled sample spacing Input: ili210x - special case ili251x sample read out Input: elantench - fix misreporting trackpoint coordinates Input: synaptics-rmi4 - Fix device hierarchy Input: i8042 - Add quirk for Fujitsu Lifebook T725 Input: cap11xx - add support for cap1206 Input: remove unused header <linux/input/cy8ctmg110_pdata.h> Input: ili210x - add ili251x firmware update support Input: ili210x - export ili251x version details via sysfs Input: ili210x - use resolution from ili251x firmware Input: pm8941-pwrkey - respect reboot_mode for warm reset reboot: export symbol 'reboot_mode' Input: max77693-haptic - drop unneeded MODULE_ALIAS Input: cpcap-pwrbutton - do not set input parent explicitly Input: max8925_onkey - don't mark comment as kernel-doc Input: ads7846 - do not attempt IRQ workaround when deferring probe Input: ads7846 - use input_set_capability() ...
| * reboot: export symbol 'reboot_mode'Shawn Guo2021-10-161-0/+1
| | | | | | | | | | | | | | | | | | | | Some drivers like Qualcomm pm8941-pwrkey need to access 'reboot_mode' for triggering reboot between cold and warm mode. Export the symbol, so that drivers built as module can still access the symbol. Signed-off-by: Shawn Guo <shawn.guo@linaro.org> Link: https://lore.kernel.org/r/20210714095850.27185-2-shawn.guo@linaro.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
* | reboot: Remove the unreachable panic after do_exit in reboot(2)Eric W. Biederman2021-10-201-1/+0
| | | | | | | | | | Link: https://lkml.kernel.org/r/20211020174406.17889-3-ebiederm@xmission.com Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
* | reboot: Add hardware protection power-offMatti Vaittinen2021-06-211-0/+79
|/ | | | | | | | | | | | | | | | | | | | | | | | | There can be few cases when we need to shut-down the system in order to protect the hardware. Currently this is done at least by the thermal core when temperature raises over certain limit. Some PMICs can also generate interrupts for example for over-current or over-voltage, voltage drops, short-circuit, ... etc. On some systems these are a sign of hardware failure and only thing to do is try to protect the rest of the hardware by shutting down the system. Add shut-down logic which can be used by all subsystems instead of implementing the shutdown in each subsystem. The logic is stolen from thermal_core with difference of using atomic_t instead of a mutex in order to allow calls directly from IRQ context and changing the WARN() to pr_emerg() as discussed here: https://lore.kernel.org/lkml/YJuPwAZroVZ%2Fw633@alley/ and here: https://lore.kernel.org/linux-iommu/20210331093104.383705-4-geert+renesas@glider.be/ Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Link: https://lore.kernel.org/r/e83ec1ca9408f90c857ea9dcdc57b14d9037b03f.1622628333.git.matti.vaittinen@fi.rohmeurope.com Signed-off-by: Mark Brown <broonie@kernel.org>
* Revert "PM: ACPI: reboot: Use S5 for reboot"Josef Bacik2021-03-181-2/+0
| | | | | | | | | | | | This reverts commit d60cd06331a3566d3305b3c7b566e79edf4e2095. This patch causes a panic when rebooting my Dell Poweredge r440. I do not have the full panic log as it's lost at that stage of the reboot and I do not have a serial console. Reverting this patch makes my system able to reboot again. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* reboot: hide from sysfs not applicable settingsMatteo Croce2020-12-151-23/+31
| | | | | | | | | | | | | | | | | Not all the reboot settings from both the kernel command line or sysfs interface are available to all platforms. Filter out reboot_type and reboot_force which are x86 only, and also remove reboot_cpu on kernels without SMP support. This saves some space, and avoid confusing the user with settings which will have no effect. Link: https://lkml.kernel.org/r/20201130173717.198952-3-mcroce@linux.microsoft.com Signed-off-by: Matteo Croce <mcroce@microsoft.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reboot: allow to override reboot type if quirks are foundMatteo Croce2020-12-151-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "reboot: sysfs improvements". Some improvements to the sysfs reboot interface: hide not working settings and support machines with known reboot quirks. This patch (of 2): On some machines a quirk can force a specific reboot type. Quirks are found during a DMI scan, the list of machines which need special reboot handling is defined in reboot_dmi_table. The kernel command line reboot= option overrides this via a global variable `reboot_default`, so that the reboot type requested in the command line is really performed. This was not true when setting the reboot type via the new sysfs interface. Fix this by setting reboot_default upon the first change, like reboot_setup() does for the command line. Link: https://lkml.kernel.org/r/20201130173717.198952-1-mcroce@linux.microsoft.com Link: https://lkml.kernel.org/r/20201130173717.198952-2-mcroce@linux.microsoft.com Signed-off-by: Matteo Croce <mcroce@microsoft.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reboot: remove cf9_safe from allowed types and rename cf9_forceMatteo Croce2020-12-151-9/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BOOT_CF9_SAFE_STR is an internal value used only by the x86 code and it's not possible to set it from userspace. Remove it, and rename 'cf9_force' to 'pci', so to make it coherent with the kernel command line reboot= option. Tested with this script: cd /sys/kernel/reboot/ for i in cold warm hard soft gpio; do echo $i >mode read j <mode [ $i = $j ] || echo "mode $i != $j" done for i in bios acpi kbd triple efi pci; do echo $i >type read j <type [ $i = $j ] || echo "type $i != $j" done for i in $(seq 0 $(nproc --ignore=1)); do echo $i >cpu read j <cpu [ $i = $j ] || echo "cpu $i != $j" done for i in 0 1; do echo $i >force read j <force [ $i = $j ] || echo "force $i != $j" done Link: https://lkml.kernel.org/r/20201113015900.543923-1-mcroce@linux.microsoft.com Fixes: eab8da48579d ("reboot: allow to specify reboot mode via sysfs") Signed-off-by: Matteo Croce <mcroce@microsoft.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nathan Chancellor <natechancellor@gmail.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reboot: allow to specify reboot mode via sysfsMatteo Croce2020-12-151-0/+206
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kernel cmdline reboot= option offers some sort of control on how the reboot is issued. We don't always know in advance what type of reboot to perform. Sometimes a warm reboot is preferred to persist certain memory regions across the reboot. Others a cold one is needed to apply a future system update that makes a memory memory model change, like changing the base page size or resizing a persistent memory region. Or simply we want to enable reboot_force because we noticed that something bad happened. Add handles in sysfs to allow setting these reboot options, so they can be changed when the system is booted, other than at boot time. The handlers are under <sysfs>/kernel/reboot, can be read to get the current configuration and written to alter it. # cd /sys/kernel/reboot/ # grep . * cpu:0 force:0 mode:cold type:acpi # echo 2 >cpu # echo yes >force # echo soft >mode # echo bios >type # grep . * cpu:2 force:1 mode:soft type:bios Before setting anything, check for CAP_SYS_BOOT capability, so it's possible to allow an unpriviledged process to change these settings simply by relaxing the handles permissions, without opening them to the world. [natechancellor@gmail.com: fix variable assignments in type_store] Link: https://lkml.kernel.org/r/20201112035023.974748-1-natechancellor@gmail.com Link: https://github.com/ClangBuiltLinux/linux/issues/1197 Link: https://lkml.kernel.org/r/20201110202746.9690-1-mcroce@linux.microsoft.com Signed-off-by: Matteo Croce <mcroce@microsoft.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Kees Cook <keescook@chromium.org> Cc: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Nathan Chancellor <natechancellor@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* reboot: refactor and comment the cpu selection codeMatteo Croce2020-12-151-13/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | Small improvements to the code, without changing the way it works: - use a local variable, to avoid a small time lapse where reboot_cpu can have an invalid value - comment the code which is not easy to understand at a glance - merge two identical code blocks into one - replace pointer arithmetics with equivalent array syntax Link: https://lkml.kernel.org/r/20201103214025.116799-4-mcroce@linux.microsoft.com Signed-off-by: Matteo Croce <mcroce@microsoft.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Fabian Frederick <fabf@skynet.be> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Robin Holt <robinmholt@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
*-. Merge branches 'pm-sleep', 'pm-acpi', 'pm-domains' and 'powercap'Rafael J. Wysocki2020-12-151-0/+2
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * pm-sleep: PM: sleep: Add dev_wakeup_path() helper PM / suspend: fix kernel-doc markup PM: sleep: Print driver flags for all devices during suspend/resume * pm-acpi: PM: ACPI: Refresh wakeup device power configuration every time PM: ACPI: PCI: Drop acpi_pm_set_bridge_wakeup() PM: ACPI: reboot: Use S5 for reboot * pm-domains: PM: domains: create debugfs nodes when adding power domains PM: domains: replace -ENOTSUPP with -EOPNOTSUPP * powercap: powercap: Adjust printing the constraint name with new line powercap: RAPL: Add AMD Fam19h RAPL support powercap: Add AMD Fam17h RAPL support powercap/intel_rapl_msr: Convert rapl_msr_priv into pointer x86/msr-index: sort AMD RAPL MSRs by address
| | * PM: ACPI: reboot: Use S5 for rebootKai-Heng Feng2020-11-101-0/+2
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After reboot, it's not possible to use hotkeys to enter BIOS setup and boot menu on some HP laptops. BIOS folks identified the root cause is the missing _PTS call, and BIOS is expecting _PTS to do proper reset. Using S5 for reboot is default behavior under Windows, "A full shutdown (S5) occurs when a system restart is requested" [1], so let's do the same here. [1] https://docs.microsoft.com/en-us/windows/win32/power/system-power-states Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com> [ rjw: Subject edit ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* | reboot: fix overflow parsing reboot cpu numberMatteo Croce2020-11-141-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Limit the CPU number to num_possible_cpus(), because setting it to a value lower than INT_MAX but higher than NR_CPUS produces the following error on reboot and shutdown: BUG: unable to handle page fault for address: ffffffff90ab1bb0 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 1c09067 P4D 1c09067 PUD 1c0a063 PMD 0 Oops: 0000 [#1] SMP CPU: 1 PID: 1 Comm: systemd-shutdow Not tainted 5.9.0-rc8-kvm #110 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:migrate_to_reboot_cpu+0xe/0x60 Code: ea ea 00 48 89 fa 48 c7 c7 30 57 f1 81 e9 fa ef ff ff 66 2e 0f 1f 84 00 00 00 00 00 53 8b 1d d5 ea ea 00 e8 14 33 fe ff 89 da <48> 0f a3 15 ea fc bd 00 48 89 d0 73 29 89 c2 c1 e8 06 65 48 8b 3c RSP: 0018:ffffc90000013e08 EFLAGS: 00010246 RAX: ffff88801f0a0000 RBX: 0000000077359400 RCX: 0000000000000000 RDX: 0000000077359400 RSI: 0000000000000002 RDI: ffffffff81c199e0 RBP: ffffffff81c1e3c0 R08: ffff88801f41f000 R09: ffffffff81c1e348 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 00007f32bedf8830 R14: 00000000fee1dead R15: 0000000000000000 FS: 00007f32bedf8980(0000) GS:ffff88801f480000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff90ab1bb0 CR3: 000000001d057000 CR4: 00000000000006a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __do_sys_reboot.cold+0x34/0x5b do_syscall_64+0x2d/0x40 Fixes: 1b3a5d02ee07 ("reboot: move arch/x86 reboot= handling to generic kernel") Signed-off-by: Matteo Croce <mcroce@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Fabian Frederick <fabf@skynet.be> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Kees Cook <keescook@chromium.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201103214025.116799-3-mcroce@linux.microsoft.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Revert "kernel/reboot.c: convert simple_strtoul to kstrtoint"Matteo Croce2020-11-141-14/+7
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "fix parsing of reboot= cmdline", v3. The parsing of the reboot= cmdline has two major errors: - a missing bound check can crash the system on reboot - parsing of the cpu number only works if specified last Fix both. This patch (of 2): This reverts commit 616feab753972b97. kstrtoint() and simple_strtoul() have a subtle difference which makes them non interchangeable: if a non digit character is found amid the parsing, the former will return an error, while the latter will just stop parsing, e.g. simple_strtoul("123xyx") = 123. The kernel cmdline reboot= argument allows to specify the CPU used for rebooting, with the syntax `s####` among the other flags, e.g. "reboot=warm,s31,force", so if this flag is not the last given, it's silently ignored as well as the subsequent ones. Fixes: 616feab75397 ("kernel/reboot.c: convert simple_strtoul to kstrtoint") Signed-off-by: Matteo Croce <mcroce@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Petr Mladek <pmladek@suse.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Mike Rapoport <rppt@kernel.org> Cc: Kees Cook <keescook@chromium.org> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Robin Holt <robinmholt@gmail.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20201103214025.116799-2-mcroce@linux.microsoft.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* arch: remove unicore32 portMike Rapoport2020-07-011-1/+1
| | | | | | | | | | | | | | | | | | | The unicore32 port do not seem maintained for a long time now, there is no upstream toolchain that can create unicore32 binaries and all the links to prebuilt toolchains for unicore32 are dead. Even compilers that were available are not supported by the kernel anymore. Guenter Roeck says: I have stopped building unicore32 images since v4.19 since there is no available compiler that is still supported by the kernel. I am surprised that support for it has not been removed from the kernel. Remove unicore32 port. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Guenter Roeck <linux@roeck-us.net>
* printk: Collapse shutdown types into a single dump reasonKees Cook2020-05-301-3/+3
| | | | | | | | | | | | | | To turn the KMSG_DUMP_* reasons into a more ordered list, collapse the redundant KMSG_DUMP_(RESTART|HALT|POWEROFF) reasons into KMSG_DUMP_SHUTDOWN. The current users already don't meaningfully distinguish between them, so there's no need to, as discussed here: https://lore.kernel.org/lkml/CA+CK2bAPv5u1ih5y9t5FUnTyximtFCtDYXJCpuyjOyHNOkRdqw@mail.gmail.com/ Link: https://lore.kernel.org/lkml/20200515184434.8470-2-keescook@chromium.org/ Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Kees Cook <keescook@chromium.org>
* treewide: Add SPDX license identifier for missed filesThomas Gleixner2019-05-211-0/+1
| | | | | | | | | | | | | | | | | Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* panic/reboot: allow specifying reboot_mode for panic onlyAaro Koskinen2019-05-141-5/+15
| | | | | | | | | | | | | Allow specifying reboot_mode for panic only. This is needed on systems where ramoops is used to store panic logs, and user wants to use warm reset to preserve those, while still having cold reset on normal reboots. Link: http://lkml.kernel.org/r/20190322004735.27702-1-aaro.koskinen@iki.fi Signed-off-by: Aaro Koskinen <aaro.koskinen@nokia.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/reboot.c: export pm_power_off_prepareOleksij Rempel2018-09-111-0/+1
| | | | | | | | | Export pm_power_off_prepare. It is needed to implement power off on Freescale/NXP iMX6 based boards with external power management integrated circuit (PMIC). Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Signed-off-by: Mark Brown <broonie@kernel.org>
* PM / reboot: Eliminate race between reboot and suspendPingfan Liu2018-08-061-3/+3
| | | | | | | | | | | | | At present, "systemctl suspend" and "shutdown" can run in parrallel. A system can suspend after devices_shutdown(), and resume. Then the shutdown task goes on to power off. This causes many devices are not really shut off. Hence replacing reboot_mutex with system_transition_mutex (renamed from pm_mutex) to achieve the exclusion. The renaming of pm_mutex as system_transition_mutex can be better to reflect the purpose of the mutex. Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Acked-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
* kernel/reboot.c: add devm_register_reboot_notifier()Andrey Smirnov2017-11-171-0/+27
| | | | | | | | | | | Add devm_* wrapper around register_reboot_notifier to simplify device specific reboot notifier registration/unregistration. [akpm@linux-foundation.org: move `struct device' forward decl to top-of-file] Link: http://lkml.kernel.org/r/20170320171753.1705-1-andrew.smirnov@gmail.com Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kexec: split kexec_load syscall from kexec core codeDave Young2015-09-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two kexec load syscalls, kexec_load another and kexec_file_load. kexec_file_load has been splited as kernel/kexec_file.c. In this patch I split kexec_load syscall code to kernel/kexec.c. And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and use kexec_file_load only, or vice verse. The original requirement is from Ted Ts'o, he want kexec kernel signature being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use kexec_load syscall can bypass the checking. Vivek Goyal proposed to create a common kconfig option so user can compile in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects KEXEC_CORE so that old config files still work. Because there's general code need CONFIG_KEXEC_CORE, so I updated all the architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects KEXEC_CORE in arch Kconfig. Also updated general kernel code with to kexec_load syscall. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Dave Young <dyoung@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Josh Boyer <jwboyer@fedoraproject.org> Cc: David Howells <dhowells@redhat.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel/reboot.c: add orderly_reboot for graceful rebootJoel Stanley2015-04-151-5/+48
| | | | | | | | | | | | | | | | | | | | | | | | | The kernel has orderly_poweroff which allows the kernel to initiate a graceful shutdown of userspace, by running /sbin/poweroff. This adds orderly_reboot that will cause userspace to shut itself down by calling /sbin/reboot. This will be used for shutdown initiated by a system controller on platforms that do not use ACPI. orderly_reboot() should be used when the system wants to allow userspace to gracefully shut itself down. For cases where the system may imminently catch on fire, the existing emergency_restart() provides an immediate reboot without involving userspace. Signed-off-by: Joel Stanley <joel@jms.id.au> Cc: Fabian Frederick <fabf@skynet.be> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Kerr <jk@ozlabs.org> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kernel: add support for kernel restart handler call chainGuenter Roeck2014-09-261-0/+81
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Various drivers implement architecture and/or device specific means to restart (reset) the system. Various mechanisms have been implemented to support those schemes. The best known mechanism is arm_pm_restart, which is a function pointer to be set either from platform specific code or from drivers. Another mechanism is to use hardware watchdogs to issue a reset; this mechanism is used if there is no other method available to reset a board or system. Two examples are alim7101_wdt, which currently uses the reboot notifier to trigger a reset, and moxart_wdt, which registers the arm_pm_restart function. The existing mechanisms have a number of drawbacks. Typically only one scheme to restart the system is supported (at least if arm_pm_restart is used). At least in theory there can be multiple means to restart the system, some of which may be less desirable (for example one mechanism may only reset the CPU, while another may reset the entire system). Using arm_pm_restart can also be racy if the function pointer is set from a driver, as the driver may be in the process of being unloaded when arm_pm_restart is called. Using the reboot notifier is always racy, as it is unknown if and when other functions using the reboot notifier have completed execution by the time the watchdog fires. Introduce a system restart handler call chain to solve the described problems. This call chain is expected to be executed from the architecture specific machine_restart() function. Drivers providing system restart functionality (such as the watchdog drivers mentioned above) are expected to register with this call chain. By using the priority field in the notifier block, callers can control restart handler execution sequence and thus ensure that the restart handler with the optimal restart capabilities for a given system is called first. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Heiko Stuebner <heiko@sntech.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Wim Van Sebroeck <wim@iguana.be> Cc: Maxime Ripard <maxime.ripard@free-electrons.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Jonas Jensen <jonas.jensen@gmail.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Tomasz Figa <t.figa@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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