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authorJordan Justen <jordan.l.justen@intel.com>2014-11-13 18:24:59 +0000
committerjljusten <jljusten@Edk2>2014-11-13 18:24:59 +0000
commitfab82c1873b792bce33fb22c32db71324fc0ac3b (patch)
treebfda1f1c1e5e7b3f8353fd893828fa9e39dd5431 /UefiCpuPkg/CpuDxe/Ia32
parent1535c888c6f06bb35881e83cd7ee49fb8554942b (diff)
downloadedk2-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/Ia32')
-rw-r--r--UefiCpuPkg/CpuDxe/Ia32/MpAsm.asm75
-rw-r--r--UefiCpuPkg/CpuDxe/Ia32/MpAsm.nasm68
2 files changed, 143 insertions, 0 deletions
diff --git a/UefiCpuPkg/CpuDxe/Ia32/MpAsm.asm b/UefiCpuPkg/CpuDxe/Ia32/MpAsm.asm
new file mode 100644
index 0000000000..d476829b91
--- /dev/null
+++ b/UefiCpuPkg/CpuDxe/Ia32/MpAsm.asm
@@ -0,0 +1,75 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
+; This program and the accompanying materials
+; are licensed and made available under the terms and conditions of the BSD License
+; which accompanies this distribution. The full text of the license may be found at
+; http://opensource.org/licenses/bsd-license.php.
+;
+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+;
+;------------------------------------------------------------------------------
+
+.586p
+.model flat, C
+
+extern mTopOfApCommonStack:DWORD
+extern ApEntryPointInC:PROC
+
+.code
+
+;
+; This lock only allows one AP to use the mTopOfApCommonStack stack at a time
+;
+ApStackLock dd 0
+
+;.code
+
+;------------------------------------------------------------------------------
+; VOID
+; EFIAPI
+; AsmApEntryPoint (
+; VOID
+; );
+;------------------------------------------------------------------------------
+AsmApEntryPoint PROC
+
+ cli
+AsmApEntryPointAcquireLock:
+lock bts dword ptr [ApStackLock], 0
+ pause
+ jc AsmApEntryPointAcquireLock
+
+ mov esp, [mTopOfApCommonStack]
+ call ApEntryPointInC
+
+ cli
+
+lock btc dword ptr [ApStackLock], 0
+
+ mov eax, 100h
+AsmApEntryPointShareLock:
+ pause
+ dec eax
+ jnz AsmApEntryPointShareLock
+
+ jmp AsmApEntryPoint
+
+AsmApEntryPoint ENDP
+
+;------------------------------------------------------------------------------
+; VOID
+; EFIAPI
+; AsmApDoneWithCommonStack (
+; VOID
+; );
+;------------------------------------------------------------------------------
+AsmApDoneWithCommonStack PROC PUBLIC
+
+lock btc dword ptr [ApStackLock], 0
+ ret
+
+AsmApDoneWithCommonStack ENDP
+
+END
diff --git a/UefiCpuPkg/CpuDxe/Ia32/MpAsm.nasm b/UefiCpuPkg/CpuDxe/Ia32/MpAsm.nasm
new file mode 100644
index 0000000000..c47cdcef54
--- /dev/null
+++ b/UefiCpuPkg/CpuDxe/Ia32/MpAsm.nasm
@@ -0,0 +1,68 @@
+;------------------------------------------------------------------------------
+;
+; Copyright (c) 2006 - 2014, Intel Corporation. All rights reserved.<BR>
+; This program and the accompanying materials
+; are licensed and made available under the terms and conditions of the BSD License
+; which accompanies this distribution. The full text of the license may be found at
+; http://opensource.org/licenses/bsd-license.php.
+;
+; THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+; WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+;
+;------------------------------------------------------------------------------
+
+extern ASM_PFX(mTopOfApCommonStack)
+extern ASM_PFX(ApEntryPointInC)
+
+SECTION .data
+
+;
+; This lock only allows one AP to use the mTopOfApCommonStack stack at a time
+;
+ApStackLock:
+ dd 0
+
+SECTION .text
+
+;------------------------------------------------------------------------------
+; VOID
+; EFIAPI
+; AsmApEntryPoint (
+; VOID
+; );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmApEntryPoint)
+ASM_PFX(AsmApEntryPoint):
+ cli
+AsmApEntryPointAcquireLock:
+lock bts dword [ApStackLock], 0
+ pause
+ jc AsmApEntryPointAcquireLock
+
+ mov esp, [ASM_PFX(mTopOfApCommonStack)]
+ call ASM_PFX(ApEntryPointInC)
+
+ cli
+
+lock btc dword [ApStackLock], 0
+
+ mov eax, 0x100
+AsmApEntryPointShareLock:
+ pause
+ dec eax
+ jnz AsmApEntryPointShareLock
+
+ jmp ASM_PFX(AsmApEntryPoint)
+
+;------------------------------------------------------------------------------
+; VOID
+; EFIAPI
+; AsmApDoneWithCommonStack (
+; VOID
+; );
+;------------------------------------------------------------------------------
+global ASM_PFX(AsmApDoneWithCommonStack)
+ASM_PFX(AsmApDoneWithCommonStack):
+lock btc dword [ApStackLock], 0
+ ret
+