On Wed, Jun 8, 2022 at 4:47 PM Peter Zijlstra <peterz@xxxxxxxxxxxxx> wrote:
All the idle routines are called with RCU disabled, as such there must
not be any tracing inside.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
This actually does some additional code duplication cleanup which
would be good to mention in the changelog. Or even move to a separate
patch for that matter.
Otherwise LGTM.
---
drivers/acpi/processor_idle.c | 24 +++++++++++++-----------
1 file changed, 13 insertions(+), 11 deletions(-)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -108,8 +108,8 @@ static const struct dmi_system_id proces
static void __cpuidle acpi_safe_halt(void)
{
if (!tif_need_resched()) {
- safe_halt();
- local_irq_disable();
+ raw_safe_halt();
+ raw_local_irq_disable();
}
}
@@ -524,16 +524,21 @@ static int acpi_idle_bm_check(void)
return bm_status;
}
-static void wait_for_freeze(void)
+static __cpuidle void io_idle(unsigned long addr)
{
+ /* IO port based C-state */
+ inb(addr);
+
#ifdef CONFIG_X86
/* No delay is needed if we are in guest */
if (boot_cpu_has(X86_FEATURE_HYPERVISOR))
return;
#endif
- /* Dummy wait op - must do something useless after P_LVL2 read
- because chipsets cannot guarantee that STPCLK# signal
- gets asserted in time to freeze execution properly. */
+ /*
+ * Dummy wait op - must do something useless after P_LVL2 read
+ * because chipsets cannot guarantee that STPCLK# signal
+ * gets asserted in time to freeze execution properly.
+ */
inl(acpi_gbl_FADT.xpm_timer_block.address);
}
@@ -553,9 +558,7 @@ static void __cpuidle acpi_idle_do_entry
} else if (cx->entry_method == ACPI_CSTATE_HALT) {
acpi_safe_halt();
} else {
- /* IO port based C-state */
- inb(cx->address);
- wait_for_freeze();
+ io_idle(cx->address);
}
perf_lopwr_cb(false);
@@ -577,8 +580,7 @@ static int acpi_idle_play_dead(struct cp
if (cx->entry_method == ACPI_CSTATE_HALT)
safe_halt();
else if (cx->entry_method == ACPI_CSTATE_SYSTEMIO) {
- inb(cx->address);
- wait_for_freeze();
+ io_idle(cx->address);
} else
return -ENODEV;
