powerpc/476: Add isync after loading mmu and debug spr's

476 requires an isync after loading MMU and debug related SPR's.  Some of
these are in performance-critical paths and may need to be optimized, but
initially, we're playing it safe.
Signed-off-by: NTorez Smith  <lnxtorez@linux.vnet.ibm.com>
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>

arch/powerpc/kernel/kprobes.c

@@ -114,6 +114,9 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 	regs->msr &= ~MSR_CE;
 	mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
+#ifdef CONFIG_PPC_47x
+	isync();
+#endif
 #endif
 
 	/*

arch/powerpc/kernel/process.c

@@ -371,6 +371,9 @@ int set_dabr(unsigned long dabr)
 	/* XXX should we have a CPU_FTR_HAS_DABR ? */
 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
 	mtspr(SPRN_DAC1, dabr);
+#ifdef CONFIG_PPC_47x
+	isync();
+#endif
 #elif defined(CONFIG_PPC_BOOK3S)
 	mtspr(SPRN_DABR, dabr);
 #endif