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d0c14a7d36
As per the (somewhat recent) comment before the definition of `__cpuidle`, the tag is like `noinstr` but also marks a function so it can be identified by cpu_in_idle(). Let's add these markings to arm64 cpuidle functions With this change we get useful backtraces like: NMI backtrace for cpu N skipped: idling at cpu_do_idle+0x94/0x98 instead of useless backtraces when dumping all processors using nmi_cpu_backtrace(). NOTE: this patch won't make cpu_in_idle() work perfectly for arm64, but it doesn't hurt and does catch some cases. Specifically an example that wasn't caught in my testing looked like this: gic_cpu_sys_reg_init+0x1f8/0x314 gic_cpu_pm_notifier+0x40/0x78 raw_notifier_call_chain+0x5c/0x134 cpu_pm_notify+0x38/0x64 cpu_pm_exit+0x20/0x2c psci_enter_idle_state+0x48/0x70 cpuidle_enter_state+0xb8/0x260 cpuidle_enter+0x44/0x5c do_idle+0x188/0x30c Acked-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Stephen Boyd <swboyd@chromium.org> Acked-by: Sumit Garg <sumit.garg@linaro.org> Tested-by: Chen-Yu Tsai <wenst@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230906090246.v13.2.I4baba13e220bdd24d11400c67f137c35f07f82c7@changeid Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
45 lines
897 B
C
45 lines
897 B
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Low-level idle sequences
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*/
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#include <linux/cpu.h>
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#include <linux/irqflags.h>
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#include <asm/barrier.h>
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#include <asm/cpuidle.h>
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#include <asm/cpufeature.h>
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#include <asm/sysreg.h>
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/*
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* cpu_do_idle()
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*
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* Idle the processor (wait for interrupt).
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*
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* If the CPU supports priority masking we must do additional work to
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* ensure that interrupts are not masked at the PMR (because the core will
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* not wake up if we block the wake up signal in the interrupt controller).
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*/
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void __cpuidle cpu_do_idle(void)
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{
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struct arm_cpuidle_irq_context context;
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arm_cpuidle_save_irq_context(&context);
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dsb(sy);
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wfi();
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arm_cpuidle_restore_irq_context(&context);
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}
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/*
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* This is our default idle handler.
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*/
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void __cpuidle arch_cpu_idle(void)
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{
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/*
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* This should do all the clock switching and wait for interrupt
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* tricks
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*/
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cpu_do_idle();
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}
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