/* All cores end up calling this whenever there is nothing left to do or they
* don't know explicitly what to do. Non-zero cores call it when they are done
* booting. Other cases include after getting a DEATH IPI.
*
* All cores attempt to run the context of any owning proc. Barring that, they
* halt and wake up when interrupted, do any work on their work queue, then halt
* again. In between, the ksched gets a chance to tell it to do something else,
* or perhaps to halt in another manner. */
static void __attribute__((noreturn)) __smp_idle(void *arg)
{
struct per_cpu_info *pcpui = &per_cpu_info[core_id()];
pcpui->cur_kthread->flags = KTH_DEFAULT_FLAGS;
while (1) {
/* This might wake a kthread (the gp ktask), so be sure to run
* PRKM after reporting the quiescent state. */
rcu_report_qs();
/* If this runs an RKM, we'll call smp_idle from the top. */
process_routine_kmsg();
try_run_proc();
cpu_bored(); /* call out to the ksched */
/* cpu_halt() atomically turns on interrupts and halts the core.
* Important to do this, since we could have a RKM come in via
* an interrupt right while PRKM is returning, and we wouldn't
* catch it. When it returns, IRQs are back off. */
__set_cpu_state(pcpui, CPU_STATE_IDLE);
cpu_halt();
__set_cpu_state(pcpui, CPU_STATE_KERNEL);
}
assert(0);
}
/* All cores end up calling this whenever there is nothing left to do or they
* don't know explicitly what to do. Non-zero cores call it when they are done
* booting. Other cases include after getting a DEATH IPI.
*
* All cores attempt to run the context of any owning proc. Barring that, they
* halt and wake up when interrupted, do any work on their work queue, then halt
* again. In between, the ksched gets a chance to tell it to do something else,
* or perhaps to halt in another manner. */
static void __attribute__((noinline, noreturn)) __smp_idle(void)
{
struct per_cpu_info *pcpui = &per_cpu_info[core_id()];
disable_irq(); /* might not be needed - need to look at KMSGs closely */
clear_rkmsg(pcpui);
pcpui->cur_kthread->flags = KTH_DEFAULT_FLAGS;
enable_irq(); /* one-shot change to get any IRQs before we halt later */
while (1) {
disable_irq();
process_routine_kmsg();
try_run_proc();
cpu_bored(); /* call out to the ksched */
/* cpu_halt() atomically turns on interrupts and halts the core.
* Important to do this, since we could have a RKM come in via an
* interrupt right while PRKM is returning, and we wouldn't catch
* it. */
__set_cpu_state(pcpui, CPU_STATE_IDLE);
cpu_halt();
/* interrupts are back on now (given our current semantics) */
}
assert(0);
}
