[PATCH v2] ACPICA: Avoid evaluating methods too early during system resume

[PATCH v2] ACPICA: Avoid evaluating methods too early during system resume

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

During wakeup from system-wide sleep states, acpi_get_sleep_type_data()
is called and it tries to get memory from the slab allocator in order
to evaluate a control method, but if KFENCE is enabled in the kernel,
the memory allocation attempt causes an IRQ work to be queued and a
self-IPI to be sent to the CPU running the code which requires the
memory controller to be ready, so if that happens too early in the
wakeup path, it doesn't work.

Prevent that from taking place by calling acpi_get_sleep_type_data()
for S0 upfront, when preparing to enter a given sleep state, and
saving the data obtained by it for later use during system wakeup.

BugLink: https://bugzilla.kernel.org/show_bug.cgi?id=214271
Reported-by: Reik Keutterling <spielkind@gmail.com>
Tested-by: Reik Keutterling <spielkind@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---

v1 -> v2:
   * Fix local variable initialization.

---
 drivers/acpi/acpica/acglobal.h  |    2 ++
 drivers/acpi/acpica/hwesleep.c  |    8 ++------
 drivers/acpi/acpica/hwsleep.c   |   11 ++++-------
 drivers/acpi/acpica/hwxfsleep.c |    7 +++++++
 4 files changed, 15 insertions(+), 13 deletions(-)

Index: linux-pm/drivers/acpi/acpica/acglobal.h
===================================================================
--- linux-pm.orig/drivers/acpi/acpica/acglobal.h
+++ linux-pm/drivers/acpi/acpica/acglobal.h
@@ -226,6 +226,8 @@ extern struct acpi_bit_register_info
     acpi_gbl_bit_register_info[ACPI_NUM_BITREG];
 ACPI_GLOBAL(u8, acpi_gbl_sleep_type_a);
 ACPI_GLOBAL(u8, acpi_gbl_sleep_type_b);
+ACPI_GLOBAL(u8, acpi_gbl_sleep_type_a_s0);
+ACPI_GLOBAL(u8, acpi_gbl_sleep_type_b_s0);
 
 /*****************************************************************************
  *
Index: linux-pm/drivers/acpi/acpica/hwxfsleep.c
===================================================================
--- linux-pm.orig/drivers/acpi/acpica/hwxfsleep.c
+++ linux-pm/drivers/acpi/acpica/hwxfsleep.c
@@ -217,6 +217,13 @@ acpi_status acpi_enter_sleep_state_prep(
 		return_ACPI_STATUS(status);
 	}
 
+	status = acpi_get_sleep_type_data(ACPI_STATE_S0,
+					  &acpi_gbl_sleep_type_a_s0,
+					  &acpi_gbl_sleep_type_b_s0);
+	if (ACPI_FAILURE(status)) {
+		acpi_gbl_sleep_type_a_s0 = ACPI_SLEEP_TYPE_INVALID;
+	}
+
 	/* Execute the _PTS method (Prepare To Sleep) */
 
 	arg_list.count = 1;
Index: linux-pm/drivers/acpi/acpica/hwsleep.c
===================================================================
--- linux-pm.orig/drivers/acpi/acpica/hwsleep.c
+++ linux-pm/drivers/acpi/acpica/hwsleep.c
@@ -179,7 +179,7 @@ acpi_status acpi_hw_legacy_sleep(u8 slee
 
 acpi_status acpi_hw_legacy_wake_prep(u8 sleep_state)
 {
-	acpi_status status;
+	acpi_status status = AE_OK;
 	struct acpi_bit_register_info *sleep_type_reg_info;
 	struct acpi_bit_register_info *sleep_enable_reg_info;
 	u32 pm1a_control;
@@ -192,10 +192,7 @@ acpi_status acpi_hw_legacy_wake_prep(u8
 	 * This is unclear from the ACPI Spec, but it is required
 	 * by some machines.
 	 */
-	status = acpi_get_sleep_type_data(ACPI_STATE_S0,
-					  &acpi_gbl_sleep_type_a,
-					  &acpi_gbl_sleep_type_b);
-	if (ACPI_SUCCESS(status)) {
+	if (acpi_gbl_sleep_type_a_s0 != ACPI_SLEEP_TYPE_INVALID) {
 		sleep_type_reg_info =
 		    acpi_hw_get_bit_register_info(ACPI_BITREG_SLEEP_TYPE);
 		sleep_enable_reg_info =
@@ -216,9 +213,9 @@ acpi_status acpi_hw_legacy_wake_prep(u8
 
 			/* Insert the SLP_TYP bits */
 
-			pm1a_control |= (acpi_gbl_sleep_type_a <<
+			pm1a_control |= (acpi_gbl_sleep_type_a_s0 <<
 					 sleep_type_reg_info->bit_position);
-			pm1b_control |= (acpi_gbl_sleep_type_b <<
+			pm1b_control |= (acpi_gbl_sleep_type_b_s0 <<
 					 sleep_type_reg_info->bit_position);
 
 			/* Write the control registers and ignore any errors */
Index: linux-pm/drivers/acpi/acpica/hwesleep.c
===================================================================
--- linux-pm.orig/drivers/acpi/acpica/hwesleep.c
+++ linux-pm/drivers/acpi/acpica/hwesleep.c
@@ -147,17 +147,13 @@ acpi_status acpi_hw_extended_sleep(u8 sl
 
 acpi_status acpi_hw_extended_wake_prep(u8 sleep_state)
 {
-	acpi_status status;
 	u8 sleep_type_value;
 
 	ACPI_FUNCTION_TRACE(hw_extended_wake_prep);
 
-	status = acpi_get_sleep_type_data(ACPI_STATE_S0,
-					  &acpi_gbl_sleep_type_a,
-					  &acpi_gbl_sleep_type_b);
-	if (ACPI_SUCCESS(status)) {
+	if (acpi_gbl_sleep_type_a_s0 != ACPI_SLEEP_TYPE_INVALID) {
 		sleep_type_value =
-		    ((acpi_gbl_sleep_type_a << ACPI_X_SLEEP_TYPE_POSITION) &
+		    ((acpi_gbl_sleep_type_a_s0 << ACPI_X_SLEEP_TYPE_POSITION) &
 		     ACPI_X_SLEEP_TYPE_MASK);
 
 		(void)acpi_write((u64)(sleep_type_value | ACPI_X_SLEEP_ENABLE),