ArmPkg: Disable watchdog interaction after exiting boot services

Update GenericWatchdogDxe to disable watchdog interaction after exiting
boot services. Also, move the mEfiExitBootServicesEvent event to the top
of the file with the other static variables.

Signed-off-by: Rebecca Cran <rebecca@os.amperecomputing.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

1 files changed, 17 insertions, 4 deletions

diff --git a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
index fdcda2be1b..5bff073bc5 100644
--- a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
+++ b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
@@ -33,10 +33,14 @@
    It is therefore stored here. 0 means the timer is not running. */

 STATIC UINT64  mTimerPeriod = 0;

 

+/* disables watchdog interaction after Exit Boot Services */

+STATIC BOOLEAN  mExitedBootServices = FALSE;

+

 #define MAX_UINT48  0xFFFFFFFFFFFFULL

 

 STATIC EFI_HARDWARE_INTERRUPT2_PROTOCOL  *mInterruptProtocol;

 STATIC EFI_WATCHDOG_TIMER_NOTIFY         mWatchdogNotify;

+STATIC EFI_EVENT                         mEfiExitBootServicesEvent;

 

 /**

   This function returns the maximum watchdog offset register value.

@@ -118,7 +122,8 @@ WatchdogExitBootServicesEvent (
   )

 {

   WatchdogDisable ();

-  mTimerPeriod = 0;

+  mTimerPeriod        = 0;

+  mExitedBootServices = TRUE;

 }

 

 /* This function is called when the watchdog's first signal (WS0) goes high.

@@ -215,6 +220,8 @@ WatchdogRegisterHandler (
 

   @retval EFI_SUCCESS           The watchdog timer has been programmed to fire

                                 in TimerPeriod 100ns units.

+  @retval EFI_DEVICE_ERROR      Boot Services has been exited but TimerPeriod

+                                is not zero.

 

 **/

 STATIC

@@ -230,7 +237,15 @@ WatchdogSetTimerPeriod (
   UINT64  TimerFrequencyHz;

   UINT64  NumTimerTicks;

 

-  // if TimerPeriod is 0, this is a request to stop the watchdog.

+  // If we've exited Boot Services but TimerPeriod isn't zero, this

+  // indicates that the caller is doing something wrong.

+  if (mExitedBootServices && (TimerPeriod != 0)) {

+    mTimerPeriod = 0;

+    WatchdogDisable ();

+    return EFI_DEVICE_ERROR;

+  }

+

+  // If TimerPeriod is 0 this is a request to stop the watchdog.

   if (TimerPeriod == 0) {

     mTimerPeriod = 0;

     WatchdogDisable ();

@@ -335,8 +350,6 @@ STATIC EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  mWatchdogTimer = {
   WatchdogGetTimerPeriod

 };

 

-STATIC EFI_EVENT  mEfiExitBootServicesEvent;

-

 EFI_STATUS

 EFIAPI

 GenericWatchdogEntry (