UefiCpuPkg/MpInitLib: Enhance waiting for AP initialization logic.

[mirror_edk2.git] / UefiCpuPkg / Library / MpInitLib / X64 / MpFuncs.nasm

diff --git a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
index 4ada6493d475738398b674e4419d9dac3e94e1aa..21d278600d1bf3878ae37b723867089e33344abd 100644 (file)
--- a/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
+++ b/UefiCpuPkg/Library/MpInitLib/X64/MpFuncs.nasm
@@ -124,6 +124,12 @@ LongModeStart:
     cmp        qword [edi], 1       ; ApInitConfig\r
     jnz        GetApicId\r
 \r
+    ; Increment the number of APs executing here as early as possible\r
+    ; This is decremented in C code when AP is finished executing\r
+    mov        edi, esi\r
+    add        edi, NumApsExecutingLocation\r
+    lock inc   dword [edi]\r
+\r
     ; AP init\r
     mov        edi, esi\r
     add        edi, LockLocation\r