UefiCpuPkg/CpuDxe: Put CPU to sleep during Idle events

When the MdeModulePkg gCoreEventIdleGuid event is signaled,
CpuSleep is called.  This will cause the CPU to sleep until
the next interrupt occurs.

Signed-off-by: jljusten
Reviewed-by: mdkinney
Reviewed-by: rsun3

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@11842 6f19259b-4bc3-4df7-8a09-765794883524

1 files changed, 33 insertions, 0 deletions

diff --git a/UefiCpuPkg/CpuDxe/CpuDxe.c b/UefiCpuPkg/CpuDxe/CpuDxe.c
index 04d76a5ceb..ad4599dab9 100644
--- a/UefiCpuPkg/CpuDxe/CpuDxe.c
+++ b/UefiCpuPkg/CpuDxe/CpuDxe.c
@@ -1155,6 +1155,25 @@ InitInterruptDescriptorTable (
 

 

 /**

+  Callback function for idle events.

+ 

+  @param  Event                 Event whose notification function is being invoked.

+  @param  Context               The pointer to the notification function's context,

+                                which is implementation-dependent.

+

+**/

+VOID

+EFIAPI

+IdleLoopEventCallback (

+  IN EFI_EVENT                Event,

+  IN VOID                     *Context

+  )

+{

+  CpuSleep ();

+}

+

+

+/**

   Initialize the state information for the CPU Architectural Protocol.

 

   @param ImageHandle     Image handle this driver.

@@ -1173,6 +1192,7 @@ InitializeCpu (
   )

 {

   EFI_STATUS  Status;

+  EFI_EVENT   IdleLoopEvent;

 

   //

   // Make sure interrupts are disabled

@@ -1204,6 +1224,19 @@ InitializeCpu (
   //

   RefreshGcdMemoryAttributes ();

 

+  //

+  // Setup a callback for idle events

+  //

+  Status = gBS->CreateEventEx (

+                  EVT_NOTIFY_SIGNAL,

+                  TPL_NOTIFY,

+                  IdleLoopEventCallback,

+                  NULL,

+                  &gIdleLoopEventGuid,

+                  &IdleLoopEvent

+                  );

+  ASSERT_EFI_ERROR (Status);

+

   return Status;

 }