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>
---
 ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c | 17 ++++++++++++++---
 1 file changed, 14 insertions(+), 3 deletions(-)

diff --git a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
index 8dd247c44e8f..189194a2b9ee 100644
--- a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
+++ b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
@@ -35,10 +35,14 @@ STATIC UINT64  mTimerPeriod = 0;
 
 STATIC UINT8  WatchdogRevision;
 
+/* 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;
 
 STATIC
 VOID
@@ -93,6 +97,7 @@ WatchdogExitBootServicesEvent (
 {
   WatchdogDisable ();
   mTimerPeriod        = 0;
+  mExitedBootServices = TRUE;
 }
 
 /* This function is called when the watchdog's first signal (WS0) goes high.
@@ -203,7 +208,15 @@ 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 ();
@@ -307,8 +320,6 @@ STATIC EFI_WATCHDOG_TIMER_ARCH_PROTOCOL  mWatchdogTimer = {
   WatchdogGetTimerPeriod
 };
 
-STATIC EFI_EVENT  mEfiExitBootServicesEvent;
-
 EFI_STATUS
 EFIAPI
 GenericWatchdogEntry (
-- 
2.34.1



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Hi Rebecca,

Thank you for this patch.
I have a minor suggestion marked inline as [SAMI].
Otherwise, this patch looks good to me.

With that fixed,
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>

Regards,

Sami Mujawar

On 19/01/2024, 15:46, "Rebecca Cran" <rebecca@os.amperecomputing.com <mailto:rebecca@os.amperecomputing.com>> wrote:


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 <mailto:rebecca@os.amperecomputing.com>>
---
ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)


diff --git a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
index 8dd247c44e8f..189194a2b9ee 100644
--- a/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
+++ b/ArmPkg/Drivers/GenericWatchdogDxe/GenericWatchdogDxe.c
@@ -35,10 +35,14 @@ STATIC UINT64 mTimerPeriod = 0;


STATIC UINT8 WatchdogRevision;


+/* 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;


STATIC
VOID
@@ -93,6 +97,7 @@ WatchdogExitBootServicesEvent (
{
WatchdogDisable ();
mTimerPeriod = 0;
+ mExitedBootServices = TRUE;
}


/* This function is called when the watchdog's first signal (WS0) goes high.
@@ -203,7 +208,15 @@ 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;
[SAMI] Minor, the function documentation header needs updating to reflect the new error code being returned.
+ }
+
+ // If TimerPeriod is 0 this is a request to stop the watchdog.
if (TimerPeriod == 0) {
mTimerPeriod = 0;
WatchdogDisable ();
@@ -307,8 +320,6 @@ STATIC EFI_WATCHDOG_TIMER_ARCH_PROTOCOL mWatchdogTimer = {
WatchdogGetTimerPeriod
};


-STATIC EFI_EVENT mEfiExitBootServicesEvent;
-
EFI_STATUS
EFIAPI
GenericWatchdogEntry (
-- 
2.34.1







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