diff mbox series

[3/4] cpuidle: pseries: Mark ->enter() functions as __cpuidle

Message ID 20230406144535.3786008-3-mpe@ellerman.id.au
State Accepted
Commit 88990745c934b14359e526033c5bc1daaf15267c
Headers show
Series [1/4] powerpc/64: Mark prep_irq_for_idle() __cpuidle | expand

Commit Message

Michael Ellerman April 6, 2023, 2:45 p.m. UTC 
Code in the idle path is not allowed to be instrumented because RCU is
disabled, see commit 0e985e9d2286 ("cpuidle: Add comments about
noinstr/__cpuidle usage").

Mark the cpuidle ->enter() callbacks as __cpuidle and use the
raw_local_irq_*() routines to ensure that is the case.

Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
 drivers/cpuidle/cpuidle-pseries.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

Comments

Sachin Sant April 11, 2023, 9:02 a.m. UTC | #1 
> On 06-Apr-2023, at 8:15 PM, Michael Ellerman <mpe@ellerman.id.au> wrote:
> 
> Code in the idle path is not allowed to be instrumented because RCU is
> disabled, see commit 0e985e9d2286 ("cpuidle: Add comments about
> noinstr/__cpuidle usage").
> 
> Mark the cpuidle ->enter() callbacks as __cpuidle and use the
> raw_local_irq_*() routines to ensure that is the case.
> 
> Reported-by: Sachin Sant <sachinp@linux.ibm.com>
> Suggested-by: Peter Zijlstra <peterz@infradead.org>
> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
> ---

Thanks for the patch. With this patch (and others from the series)
applied, I no longer observe the reported kernel warning while running
ftrace selftests.

For this and other patches in the series

Tested-by: Sachin Sant <sachinp@linux.ibm.com>

- Sachin
diff mbox series

Patch

diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c
index 1bad4d2b7be3..a7d33f3ee01e 100644
--- a/drivers/cpuidle/cpuidle-pseries.c
+++ b/drivers/cpuidle/cpuidle-pseries.c
@@ -33,16 +33,16 @@  static struct cpuidle_state *cpuidle_state_table __read_mostly;
 static u64 snooze_timeout __read_mostly;
 static bool snooze_timeout_en __read_mostly;
 
-static int snooze_loop(struct cpuidle_device *dev,
-			struct cpuidle_driver *drv,
-			int index)
+static __cpuidle
+int snooze_loop(struct cpuidle_device *dev, struct cpuidle_driver *drv,
+		int index)
 {
 	u64 snooze_exit_time;
 
 	set_thread_flag(TIF_POLLING_NRFLAG);
 
 	pseries_idle_prolog();
-	local_irq_enable();
+	raw_local_irq_enable();
 	snooze_exit_time = get_tb() + snooze_timeout;
 	dev->poll_time_limit = false;
 
@@ -65,14 +65,14 @@  static int snooze_loop(struct cpuidle_device *dev,
 	HMT_medium();
 	clear_thread_flag(TIF_POLLING_NRFLAG);
 
-	local_irq_disable();
+	raw_local_irq_disable();
 
 	pseries_idle_epilog();
 
 	return index;
 }
 
-static void check_and_cede_processor(void)
+static __cpuidle void check_and_cede_processor(void)
 {
 	/*
 	 * Ensure our interrupt state is properly tracked,
@@ -216,9 +216,9 @@  static int __init parse_cede_parameters(void)
 #define NR_DEDICATED_STATES	2 /* snooze, CEDE */
 static u8 cede_latency_hint[NR_DEDICATED_STATES];
 
-static int dedicated_cede_loop(struct cpuidle_device *dev,
-				struct cpuidle_driver *drv,
-				int index)
+static __cpuidle
+int dedicated_cede_loop(struct cpuidle_device *dev, struct cpuidle_driver *drv,
+			int index)
 {
 	u8 old_latency_hint;
 
@@ -230,7 +230,7 @@  static int dedicated_cede_loop(struct cpuidle_device *dev,
 	HMT_medium();
 	check_and_cede_processor();
 
-	local_irq_disable();
+	raw_local_irq_disable();
 	get_lppaca()->donate_dedicated_cpu = 0;
 	get_lppaca()->cede_latency_hint = old_latency_hint;
 
@@ -239,9 +239,9 @@  static int dedicated_cede_loop(struct cpuidle_device *dev,
 	return index;
 }
 
-static int shared_cede_loop(struct cpuidle_device *dev,
-			struct cpuidle_driver *drv,
-			int index)
+static __cpuidle
+int shared_cede_loop(struct cpuidle_device *dev, struct cpuidle_driver *drv,
+		     int index)
 {
 
 	pseries_idle_prolog();
@@ -255,7 +255,7 @@  static int shared_cede_loop(struct cpuidle_device *dev,
 	 */
 	check_and_cede_processor();
 
-	local_irq_disable();
+	raw_local_irq_disable();
 	pseries_idle_epilog();
 
 	return index;