From: oliviermartin <oliviermartin@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Mon, 26 Mar 2012 11:01:21 +0000 (+0000)
Subject: ArmLib/ArmV7: Add ISB to ArmEnableVFP
X-Git-Tag: edk2-stable201903~13540
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=18029bb9112f7af8c9aedcf0dacbdd5267eb258c;hp=eac42a514b8bfd5d6273d673d8d24a424b579d1c;p=mirror_edk2.git

ArmLib/ArmV7: Add ISB to ArmEnableVFP

ArmEnableVFP could crash on an out-of-order CPU. Adding an instruction barrier after writing to CPACR cures the problem.

Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>
Reviewed-by: Olivier Martin <olivier.martin@arm.com>



git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13134 6f19259b-4bc3-4df7-8a09-765794883524
---

diff --git a/ArmPkg/Library/ArmLib/ArmV7/ArmV7Support.S b/ArmPkg/Library/ArmLib/ArmV7/ArmV7Support.S
index 3bb601541d..5ac3552403 100644
--- a/ArmPkg/Library/ArmLib/ArmV7/ArmV7Support.S
+++ b/ArmPkg/Library/ArmLib/ArmV7/ArmV7Support.S
@@ -347,6 +347,7 @@ ASM_PFX(ArmEnableVFP):
   orr     r0, r0, #0x00f00000
   # Write back CPACR (Coprocessor Access Control Register)
   mcr     p15, 0, r0, c1, c0, 2
+  isb
   # Set EN bit in FPEXC. The Advanced SIMD and VFP extensions are enabled and operate normally.
   mov     r0, #0x40000000
   mcr     p10,#0x7,r0,c8,c0,#0
diff --git a/ArmPkg/Library/ArmLib/ArmV7/ArmV7Support.asm b/ArmPkg/Library/ArmLib/ArmV7/ArmV7Support.asm
index 28a4564aca..8fedcdba97 100644
--- a/ArmPkg/Library/ArmLib/ArmV7/ArmV7Support.asm
+++ b/ArmPkg/Library/ArmLib/ArmV7/ArmV7Support.asm
@@ -341,6 +341,7 @@ ArmEnableVFP
   orr     r0, r0, #0x00f00000
   // Write back CPACR (Coprocessor Access Control Register)
   mcr     p15, 0, r0, c1, c0, 2
+  isb
   // Set EN bit in FPEXC. The Advanced SIMD and VFP extensions are enabled and operate normally.
   mov     r0, #0x40000000
   mcr     p10,#0x7,r0,c8,c0,#0
diff --git a/ArmPkg/Library/ArmLib/Common/ArmLibSupport.S b/ArmPkg/Library/ArmLib/Common/ArmLibSupport.S
index edd94d2995..d00a3623c5 100644
--- a/ArmPkg/Library/ArmLib/Common/ArmLibSupport.S
+++ b/ArmPkg/Library/ArmLib/Common/ArmLibSupport.S
@@ -88,6 +88,7 @@ ASM_PFX(CPSRRead):
 
 ASM_PFX(ArmWriteCPACR):
   mcr     p15, 0, r0, c1, c0, 2
+  isb
   bx      lr
 
 ASM_PFX(ArmWriteAuxCr):
diff --git a/ArmPkg/Library/ArmLib/Common/ArmLibSupport.asm b/ArmPkg/Library/ArmLib/Common/ArmLibSupport.asm
index 3f603873f3..b892603518 100644
--- a/ArmPkg/Library/ArmLib/Common/ArmLibSupport.asm
+++ b/ArmPkg/Library/ArmLib/Common/ArmLibSupport.asm
@@ -88,6 +88,7 @@ CPSRRead
 
 ArmWriteCPACR
   mcr     p15, 0, r0, c1, c0, 2
+  isb
   bx      lr
 
 ArmWriteAuxCr