mirror of
https://github.com/torvalds/linux.git
synced 2024-11-25 13:41:51 +00:00
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>
46 lines
897 B
C
46 lines
897 B
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Low-level idle sequences
|
|
*/
|
|
|
|
#include <linux/cpu.h>
|
|
#include <linux/irqflags.h>
|
|
|
|
#include <asm/barrier.h>
|
|
#include <asm/cpuidle.h>
|
|
#include <asm/cpufeature.h>
|
|
#include <asm/sysreg.h>
|
|
|
|
/*
|
|
* cpu_do_idle()
|
|
*
|
|
* Idle the processor (wait for interrupt).
|
|
*
|
|
* If the CPU supports priority masking we must do additional work to
|
|
* ensure that interrupts are not masked at the PMR (because the core will
|
|
* not wake up if we block the wake up signal in the interrupt controller).
|
|
*/
|
|
void __cpuidle cpu_do_idle(void)
|
|
{
|
|
struct arm_cpuidle_irq_context context;
|
|
|
|
arm_cpuidle_save_irq_context(&context);
|
|
|
|
dsb(sy);
|
|
wfi();
|
|
|
|
arm_cpuidle_restore_irq_context(&context);
|
|
}
|
|
|
|
/*
|
|
* This is our default idle handler.
|
|
*/
|
|
void __cpuidle arch_cpu_idle(void)
|
|
{
|
|
/*
|
|
* This should do all the clock switching and wait for interrupt
|
|
* tricks
|
|
*/
|
|
cpu_do_idle();
|
|
}
|