diff options
| author | Jordan Justen <jordan.l.justen@intel.com> | 2014-11-13 18:24:59 +0000 |
|---|---|---|
| committer | jljusten <jljusten@Edk2> | 2014-11-13 18:24:59 +0000 |
| commit | fab82c1873b792bce33fb22c32db71324fc0ac3b (patch) | |
| tree | bfda1f1c1e5e7b3f8353fd893828fa9e39dd5431 /UefiCpuPkg/CpuDxe/CpuMp.h | |
| parent | 1535c888c6f06bb35881e83cd7ee49fb8554942b (diff) | |
| download | edk2-platforms-fab82c1873b792bce33fb22c32db71324fc0ac3b.tar.xz | |
UefiCpuPkg/CpuDxe: Add stackless assembly AP entry points
The AP startup code simply jumps into this code with the CpuDxe driver
without setting up a stack for the processor.
Therefore, this code must setup the stack before calling into C code.
This is the basic flow:
* AP enters CpuDxe driver code (AsmApEntryPoint) without stack
- AP grabs a lock
- AP sets up stack
- AP calls CpuMp.c:ApEntryPointInC
- If ApEntryPointInC returns, the lock is freed, and another AP may
run
- The AP C code may call AsmApDoneWithCommonStack to indicate that
the AP is no longer using the stack, and another may therefore
proceed to use the stack and then call ApEntryPointInC
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16347 6f19259b-4bc3-4df7-8a09-765794883524
Diffstat (limited to 'UefiCpuPkg/CpuDxe/CpuMp.h')
| -rw-r--r-- | UefiCpuPkg/CpuDxe/CpuMp.h | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/UefiCpuPkg/CpuDxe/CpuMp.h b/UefiCpuPkg/CpuDxe/CpuMp.h index 93d054002a..dd2d0e1200 100644 --- a/UefiCpuPkg/CpuDxe/CpuMp.h +++ b/UefiCpuPkg/CpuDxe/CpuMp.h @@ -24,5 +24,32 @@ InitializeMpSupport ( VOID
);
+/**
+ The AP entry point that the Startup-IPI target code will jump to.
+
+ The processor jumps to this code in flat mode, but the processor's
+ stack is not initialized.
+
+**/
+VOID
+EFIAPI
+AsmApEntryPoint (
+ VOID
+ );
+
+/**
+ Releases the lock preventing other APs from using the shared AP
+ stack.
+
+ Once the AP has transitioned to using a new stack, it can call this
+ function to allow another AP to proceed with using the shared stack.
+
+**/
+VOID
+EFIAPI
+AsmApDoneWithCommonStack (
+ VOID
+ );
+
#endif // _CPU_MP_H_
|