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-rw-r--r--arch/powerpc/kernel/misc_64.S33
1 files changed, 33 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 942951e7658..4dd70cf7bb4 100644
--- a/arch/powerpc/kernel/misc_64.S
+++ b/arch/powerpc/kernel/misc_64.S
@@ -506,6 +506,39 @@ _GLOBAL(giveup_altivec)
#endif /* CONFIG_ALTIVEC */
+#ifdef CONFIG_VSX
+/*
+ * __giveup_vsx(tsk)
+ * Disable VSX for the task given as the argument.
+ * Does NOT save vsx registers.
+ * Enables the VSX for use in the kernel on return.
+ */
+_GLOBAL(__giveup_vsx)
+ mfmsr r5
+ oris r5,r5,MSR_VSX@h
+ mtmsrd r5 /* enable use of VSX now */
+ isync
+
+ cmpdi 0,r3,0
+ beqlr- /* if no previous owner, done */
+ addi r3,r3,THREAD /* want THREAD of task */
+ ld r5,PT_REGS(r3)
+ cmpdi 0,r5,0
+ beq 1f
+ ld r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+ lis r3,MSR_VSX@h
+ andc r4,r4,r3 /* disable VSX for previous task */
+ std r4,_MSR-STACK_FRAME_OVERHEAD(r5)
+1:
+#ifndef CONFIG_SMP
+ li r5,0
+ ld r4,last_task_used_vsx@got(r2)
+ std r5,0(r4)
+#endif /* CONFIG_SMP */
+ blr
+
+#endif /* CONFIG_VSX */
+
/* kexec_wait(phys_cpu)
*
* wait for the flag to change, indicating this kernel is going away but