powerpc: create flush_all_to_thread()

Create a single function that flushes everything (FP, VMX, VSX, SPE).
Doing this all at once means we only do one MSR write.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/switch_to.h

@@ -27,6 +27,7 @@ extern void giveup_vsx(struct task_struct *);
 extern void enable_kernel_spe(void);
 extern void load_up_spe(struct task_struct *);
 extern void giveup_all(struct task_struct *);
+extern void flush_all_to_thread(struct task_struct *);
 extern void switch_booke_debug_regs(struct debug_reg *new_debug);
 
 #ifdef CONFIG_PPC_FPU

arch/powerpc/kernel/process.c

@@ -367,6 +367,23 @@ void giveup_all(struct task_struct *tsk)
 }
 EXPORT_SYMBOL(giveup_all);
 
+void flush_all_to_thread(struct task_struct *tsk)
+{
+	if (tsk->thread.regs) {
+		preempt_disable();
+		BUG_ON(tsk != current);
+		giveup_all(tsk);
+
+#ifdef CONFIG_SPE
+		if (tsk->thread.regs->msr & MSR_SPE)
+			tsk->thread.spefscr = mfspr(SPRN_SPEFSCR);
+#endif
+
+		preempt_enable();
+	}
+}
+EXPORT_SYMBOL(flush_all_to_thread);
+
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 void do_send_trap(struct pt_regs *regs, unsigned long address,
 		  unsigned long error_code, int signal_code, int breakpt)
@@ -1137,10 +1154,7 @@ release_thread(struct task_struct *t)
  */
 int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
 {
-	flush_fp_to_thread(src);
-	flush_altivec_to_thread(src);
-	flush_vsx_to_thread(src);
-	flush_spe_to_thread(src);
+	flush_all_to_thread(src);
 	/*
 	 * Flush TM state out so we can copy it.  __switch_to_tm() does this
 	 * flush but it removes the checkpointed state from the current CPU and

arch/powerpc/kernel/swsusp.c

@@ -20,9 +20,7 @@ void save_processor_state(void)
 	 * flush out all the special registers so we don't need
 	 * to save them in the snapshot
 	 */
-	flush_fp_to_thread(current);
-	flush_altivec_to_thread(current);
-	flush_spe_to_thread(current);
+	flush_all_to_thread(current);
 
 #ifdef CONFIG_PPC64
 	hard_irq_disable();

arch/powerpc/kvm/book3s_hv.c

@@ -2700,9 +2700,8 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
 			goto out;
 	}
 
-	flush_fp_to_thread(current);
-	flush_altivec_to_thread(current);
-	flush_vsx_to_thread(current);
+	flush_all_to_thread(current);
+
 	vcpu->arch.wqp = &vcpu->arch.vcore->wq;
 	vcpu->arch.pgdir = current->mm->pgd;
 	vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;