riscv: move sifive_l2_cache.c to drivers/soc

The sifive_l2_cache.c is in no way related to RISC-V architecture
memory management.  It is a little stub driver working around the fact
that the EDAC maintainers prefer their drivers to be structured in a
certain way that doesn't fit the SiFive SOCs.

Move the file to drivers/soc and add a Kconfig option for it, as well
as the whole drivers/soc boilerplate for CONFIG_SOC_SIFIVE.

Fixes: a967a28 ("RISC-V: sifive_l2_cache: Add L2 cache controller driver for SiFive SoCs")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
[paul.walmsley@sifive.com: keep the MAINTAINERS change specific to the L2$ controller code]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>

MAINTAINERS

@@ -6027,6 +6027,7 @@ M:	Yash Shah <yash.shah@sifive.com>
 L:	linux-edac@vger.kernel.org
 S:	Supported
 F:	drivers/edac/sifive_edac.c
+F:	drivers/soc/sifive_l2_cache.c
 
 EDAC-SKYLAKE
 M:	Tony Luck <tony.luck@intel.com>

arch/riscv/mm/Makefile

@@ -10,7 +10,6 @@ obj-y += extable.o
 obj-$(CONFIG_MMU) += fault.o
 obj-y += cacheflush.o
 obj-y += context.o
-obj-y += sifive_l2_cache.o
 
 ifeq ($(CONFIG_MMU),y)
 obj-$(CONFIG_SMP) += tlbflush.o

drivers/edac/Kconfig

@@ -462,7 +462,7 @@ config EDAC_ALTERA_SDMMC
 
 config EDAC_SIFIVE
 	bool "Sifive platform EDAC driver"
-	depends on EDAC=y && RISCV
+	depends on EDAC=y && SIFIVE_L2
 	help
 	  Support for error detection and correction on the SiFive SoCs.
 

drivers/soc/Kconfig

@@ -14,6 +14,7 @@ source "drivers/soc/qcom/Kconfig"
 source "drivers/soc/renesas/Kconfig"
 source "drivers/soc/rockchip/Kconfig"
 source "drivers/soc/samsung/Kconfig"
+source "drivers/soc/sifive/Kconfig"
 source "drivers/soc/sunxi/Kconfig"
 source "drivers/soc/tegra/Kconfig"
 source "drivers/soc/ti/Kconfig"

drivers/soc/Makefile

@@ -20,6 +20,7 @@ obj-y				+= qcom/
 obj-y				+= renesas/
 obj-$(CONFIG_ARCH_ROCKCHIP)	+= rockchip/
 obj-$(CONFIG_SOC_SAMSUNG)	+= samsung/
+obj-$(CONFIG_SOC_SIFIVE)	+= sifive/
 obj-y				+= sunxi/
 obj-$(CONFIG_ARCH_TEGRA)	+= tegra/
 obj-y				+= ti/

drivers/soc/sifive/Kconfig

@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0
+
+if SOC_SIFIVE
+
+config SIFIVE_L2
+	bool "Sifive L2 Cache controller"
+	help
+	  Support for the L2 cache controller on SiFive platforms.
+
+endif

drivers/soc/sifive/Makefile

@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_SIFIVE_L2)	+= sifive_l2_cache.o