powerpc: Add VSX context save/restore, ptrace and signal support

[linux-2.6-omap-h63xx.git] / arch / powerpc / kernel / misc_64.S

diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S
index 942951e7658643f7d8a1bd33ebcad449d4f6d5de..31b9026cf1e377dd5286e5b463b828acbd2604fc 100644 (file)
--- 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,
+ * and save the vector registers in its thread_struct.
+ * 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