MIPS: smp-cps: Fix entry code cache flush for systems with coherent I/O

The dma_cache_wback_inv function performs exactly as is required here,
unless the system has coherent I/O in which case it's a no-op. Call the
underlying cache writeback functions directly, which is arguably clearer
anyway given that the code doesn't actually have anything to do with
DMA in a strict sense.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/7282/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/smp-cps.c

@@ -14,13 +14,14 @@
 #include <linux/smp.h>
 #include <linux/types.h>
 
-#include <asm/cacheflush.h>
+#include <asm/bcache.h>
 #include <asm/gic.h>
 #include <asm/mips-cm.h>
 #include <asm/mips-cpc.h>
 #include <asm/mips_mt.h>
 #include <asm/mipsregs.h>
 #include <asm/pm-cps.h>
+#include <asm/r4kcache.h>
 #include <asm/smp-cps.h>
 #include <asm/time.h>
 #include <asm/uasm.h>
@@ -132,8 +133,11 @@ static void __init cps_prepare_cpus(unsigned int max_cpus)
 	entry_code = (u32 *)&mips_cps_core_entry;
 	UASM_i_LA(&entry_code, 3, (long)mips_cm_base);
 	uasm_i_addiu(&entry_code, 16, 0, cca);
-	dma_cache_wback_inv((unsigned long)&mips_cps_core_entry,
-			    (void *)entry_code - (void *)&mips_cps_core_entry);
+	blast_dcache_range((unsigned long)&mips_cps_core_entry,
+			   (unsigned long)entry_code);
+	bc_wback_inv((unsigned long)&mips_cps_core_entry,
+		     (void *)entry_code - (void *)&mips_cps_core_entry);
+	__sync();
 
 	/* Allocate core boot configuration structs */
 	mips_cps_core_bootcfg = kcalloc(ncores, sizeof(*mips_cps_core_bootcfg),