riscv: lib: implement enable_caches for sifive cache

The enable_caches is a generic hook for architecture-implemented, we
define this function to enable composable cache of sifive platforms.

In sifive_cache, it invokes the generic cache_enable interface of cache
uclass to execute the relative implementation in SiFive ccache driver.

Signed-off-by: Zong Li <zong.li@sifive.com>
Reviewed-by: Rick Chen <rick@andestech.com>

arch/riscv/Kconfig

@@ -179,6 +179,11 @@ config SPL_SIFIVE_CLINT
 	  The SiFive CLINT block holds memory-mapped control and status registers
 	  associated with software and timer interrupts.
 
+config SIFIVE_CACHE
+	bool
+	help
+	  This enables the operations to configure SiFive cache
+
 config ANDES_PLIC
 	bool
 	depends on RISCV_MMODE || SPL_RISCV_MMODE

arch/riscv/lib/Makefile

@@ -10,6 +10,7 @@ obj-$(CONFIG_CMD_BOOTM) += bootm.o
 obj-$(CONFIG_CMD_BOOTI) += bootm.o image.o
 obj-$(CONFIG_CMD_GO) += boot.o
 obj-y	+= cache.o
+obj-$(CONFIG_SIFIVE_CACHE) += sifive_cache.o
 ifeq ($(CONFIG_$(SPL_)RISCV_MMODE),y)
 obj-$(CONFIG_$(SPL_)SIFIVE_CLINT) += sifive_clint.o
 obj-$(CONFIG_ANDES_PLIC) += andes_plic.o

arch/riscv/lib/sifive_cache.c

@@ -0,0 +1,27 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2021 SiFive, Inc
+ */
+
+#include <common.h>
+#include <cache.h>
+#include <cpu_func.h>
+#include <dm.h>
+
+void enable_caches(void)
+{
+	struct udevice *dev;
+	int ret;
+
+	/* Enable ways of ccache */
+	ret = uclass_get_device_by_driver(UCLASS_CACHE,
+					  DM_DRIVER_GET(sifive_ccache),
+					  &dev);
+	if (ret) {
+		log_debug("Cannot enable cache ways");
+	} else {
+		ret = cache_enable(dev);
+		if (ret)
+			log_debug("ccache enable failed");
+	}
+}