kernel/linux.git/include/linux/cpuidle.h, branch v6.6.132

cpuidle, arm64: Fix the ARM64 cpuidle logic

2023-01-18T11:27:17+00:00

The recent cpuidle changes started triggering RCU splats on Juno development boards: | ============================= | WARNING: suspicious RCU usage | ----------------------------- | include/trace/events/ipi.h:19 suspicious rcu_dereference_check() usage! Fix cpuidle on ARM64: - ... by introducing a new 'is_rcu' flag to the cpuidle helpers & make ARM64 use it, as ARM64 wants to keep RCU active longer and wants to do the ct_cpuidle_enter()/exit() dance itself. - Also update the PSCI driver accordingly. - This also removes the last known RCU_NONIDLE() user as a bonus. Reported-by: Mark Rutland Signed-off-by: Peter Zijlstra Signed-off-by: Ingo Molnar Tested-by: Sudeep Holla Tested-by: Mark Rutland Reviewed-by: Mark Rutland Link: https://lore.kernel.org/r/Y8Z31UbzG3LJgAXE@hirez.programming.kicks-ass.net --

cpuidle: Fix ct_idle_*() usage

2023-01-13T10:48:15+00:00

The whole disable-RCU, enable-IRQS dance is very intricate since changing IRQ state is traced, which depends on RCU. Add two helpers for the cpuidle case that mirror the entry code: ct_cpuidle_enter() ct_cpuidle_exit() And fix all the cases where the enter/exit dance was buggy. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Tested-by: Tony Lindgren Tested-by: Ulf Hansson Acked-by: Rafael J. Wysocki Acked-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20230112195540.130014793@infradead.org

cpuidle, dt: Push RCU-idle into driver

2023-01-13T10:48:00+00:00

Doing RCU-idle outside the driver, only to then temporarily enable it again before going idle is suboptimal. Notably: this converts all dt_init_idle_driver() and __CPU_PM_CPU_IDLE_ENTER() users for they are inextrably intertwined. Signed-off-by: Peter Zijlstra (Intel) Signed-off-by: Ingo Molnar Tested-by: Tony Lindgren Tested-by: Ulf Hansson Acked-by: Rafael J. Wysocki Acked-by: Frederic Weisbecker Link: https://lore.kernel.org/r/20230112195540.068981667@infradead.org

cpuidle: Use s64 as exit_latency_ns and target_residency_ns data type

2021-04-07T17:26:44+00:00

Subsequent changes will cause the exit_latency_ns and target_residency_ns fields in struct cpuidle_state to be used in computations in which data type conversions to u64 may turn a negative number close to zero into a verly large positive number leading to incorrect results. In preparation for that, change the data type of the fields mentioned above to s64, but ensure that they will not be negative themselves. No intentional functional impact. Signed-off-by: Rafael J. Wysocki

cpuidle: Remove pointless stub

2020-10-16T15:21:51+00:00

The cpuidle.h header is declaring a function with an empty stub for the cpuidle disabled case, but that function is only called by cpuidle governors which depend on cpuidle anyway. In other words, the function is only called when cpuidle is enabled, so there is no need for the stub. Remove the pointless stub. Signed-off-by: Daniel Lezcano [ rjw: Changelog edits ] Signed-off-by: Rafael J. Wysocki

cpuidle: record state entry rejection statistics

2020-09-23T12:10:31+00:00

CPUs may fail to enter the chosen idle state if there was a pending interrupt, causing the cpuidle driver to return an error value. Record that and export it via sysfs along with the other idle state statistics. This could prove useful in understanding behavior of the governor and the system during usecases that involve multiple CPUs. Signed-off-by: Lina Iyer [ rjw: Changelog and documentation edits ] Signed-off-by: Rafael J. Wysocki

cpuidle: Allow cpuidle drivers to take over RCU-idle

2020-09-16T17:36:26+00:00

Some drivers have to do significant work, some of which relies on RCU still being active. Instead of using RCU_NONIDLE in the drivers and flipping RCU back on, allow drivers to take over RCU-idle duty. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Ulf Hansson Tested-by: Borislav Petkov Signed-off-by: Rafael J. Wysocki

cpuidle: Make CPUIDLE_FLAG_TLB_FLUSHED generic

2020-08-26T10:41:53+00:00

This allows moving the leave_mm() call into generic code before rcu_idle_enter(). Gets rid of more trace_*_rcuidle() users. Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Steven Rostedt (VMware) Reviewed-by: Thomas Gleixner Acked-by: Rafael J. Wysocki Tested-by: Marco Elver Link: https://lkml.kernel.org/r/20200821085348.369441600@infradead.org

cpuidle: change enter_s2idle() prototype

2020-07-29T16:38:30+00:00

Control Flow Integrity(CFI) is a security mechanism that disallows changes to the original control flow graph of a compiled binary, making it significantly harder to perform such attacks. init_state_node() assign same function callback to different function pointer declarations. static int init_state_node(struct cpuidle_state *idle_state, const struct of_device_id *matches, struct device_node *state_node) { ... idle_state->enter = match_id->data; ... idle_state->enter_s2idle = match_id->data; } Function declarations: struct cpuidle_state { ... int (*enter) (struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); void (*enter_s2idle) (struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); }; In this case, either enter() or enter_s2idle() would cause CFI check failed since they use same callee. Align function prototype of enter() since it needs return value for some use cases. The return value of enter_s2idle() is no need currently. Signed-off-by: Neal Liu Reviewed-by: Sami Tolvanen Signed-off-by: Rafael J. Wysocki

Merge branch 'intel_idle+acpi'

2020-01-22T23:35:50+00:00

Merge changes updating the ACPI processor driver in order to export acpi_processor_evaluate_cst() to the code outside of it and adding ACPI support to the intel_idle driver based on that. * intel_idle+acpi: Documentation: admin-guide: PM: Add intel_idle document intel_idle: Use ACPI _CST on server systems intel_idle: Add module parameter to prevent ACPI _CST from being used intel_idle: Allow ACPI _CST to be used for selected known processors cpuidle: Allow idle states to be disabled by default intel_idle: Use ACPI _CST for processor models without C-state tables intel_idle: Refactor intel_idle_cpuidle_driver_init() ACPI: processor: Export acpi_processor_evaluate_cst() ACPI: processor: Make ACPI_PROCESSOR_CSTATE depend on ACPI_PROCESSOR ACPI: processor: Clean up acpi_processor_evaluate_cst() ACPI: processor: Introduce acpi_processor_evaluate_cst() ACPI: processor: Export function to claim _CST control