Disable VSX instruction

VSX bit is enabled by default for Power7 and Power8 CPU models,
so we need to disable them in order to avoid instruction exceptions.
Kernel will activate it when necessary.

* grub-core/kern/powerpc/ieee1275/startup.S: Disable VSX.

Also-By: Adhemerval Zanella <azanella@linux.vnet.ibm.com>
Origin: other, https://lists.gnu.org/archive/html/grub-devel/2014-09/msg00078.html
Last-Update: 2014-09-26

Patch-Name: ppc64el-disable-vsx.patch

diff --git a/grub-core/kern/powerpc/ieee1275/startup.S b/grub-core/kern/powerpc/ieee1275/startup.S
index 21c884b433897e1dae15b06d1340ce0280f77c31..b4d9c219f0668b650720e7e4711bcdc52cfe8d45 100644 (file)
--- a/grub-core/kern/powerpc/ieee1275/startup.S
+++ b/grub-core/kern/powerpc/ieee1275/startup.S
@@ -20,6 +20,8 @@
 #include <grub/symbol.h>
 #include <grub/offsets.h>
 
+#define MSR_VSX 0x80
+
 .extern __bss_start
 .extern _end
 
@@ -28,6 +30,14 @@
        .globl  start, _start
 start:
 _start:
+ _start:
+
+    /* Disable VSX instruction */
+       mfmsr  0
+       oris   0,0,MSR_VSX
+       mtmsrd 0
+       isync
+
        li      2, 0
        li      13, 0