ARM: tegra: flush caches via SMC call

On Tegra186, it is necessary to perform an SMC to fully flush all caches;
flushing/cleaning by set/way is not enough. Implement the required hook
to make this happen.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

arch/arm/mach-tegra/tegra186/Makefile

@@ -3,5 +3,6 @@
 # SPDX-License-Identifier: GPL-2.0
 
 obj-y += ../board186.o
+obj-y += cache.o
 obj-y += nvtboot_ll.o
 obj-y += nvtboot_mem.o

arch/arm/mach-tegra/tegra186/cache.c

@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2016, NVIDIA CORPORATION.
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <asm/system.h>
+
+#define SMC_SIP_INVOKE_MCE	0x82FFFF00
+#define MCE_SMC_ROC_FLUSH_CACHE	11
+
+int __asm_flush_l3_cache(void)
+{
+	struct pt_regs regs = {0};
+
+	isb();
+
+	regs.regs[0] = SMC_SIP_INVOKE_MCE | MCE_SMC_ROC_FLUSH_CACHE;
+	smc_call(&regs);
+
+	return 0;
+}