m68knommu: support ColdFire caches that do copyback and write-through

The version 3 and version 4 ColdFire cache controllers support both
write-through and copy-back modes on the data cache. Allow for Kconfig
time configuration of this, and set the cache mode appropriately.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>

arch/m68k/include/asm/m53xxacr.h

@@ -53,6 +53,12 @@
  * CACR is cache inhibited, we use the ACR register to set cacheing
  * enabled on the regions we want (eg RAM).
  */
+#if defined(CONFIG_CACHE_COPYBACK)
+#define CACHE_TYPE	ACR_CM_CB
+#else
+#define CACHE_TYPE	ACR_CM_WT
+#endif
+
 #ifdef CONFIG_COLDFIRE_SW_A7
 #define CACHE_MODE	(CACR_EC + CACR_ESB + CACR_DCM_PRE)
 #else
@@ -63,7 +69,7 @@
 
 #define ACR0_MODE	((CONFIG_RAMBASE & 0xff000000) + \
 			 (0x000f0000) + \
-			 (ACR_ENABLE + ACR_ANY + ACR_CM_CB))
+			 (ACR_ENABLE + ACR_ANY + CACHE_TYPE))
 #define ACR1_MODE	0
 
 /****************************************************************************/

arch/m68k/include/asm/m54xxacr.h

@@ -73,7 +73,11 @@
 #else
 #define CACHE_MODE (CACR_DEC+CACR_DESB+CACR_DDCM_P+CACR_BEC+CACR_IEC+CACR_EUSP)
 #endif
+#if defined(CONFIG_CACHE_COPYBACK)
+#define DATA_CACHE_MODE (ACR_ENABLE+ACR_ANY+ACR_CM_CP)
+#else
 #define DATA_CACHE_MODE (ACR_ENABLE+ACR_ANY+ACR_CM_WT)
+#endif
 #define INSN_CACHE_MODE (ACR_ENABLE+ACR_ANY)
 
 #define CACHE_INIT	(CACR_DCINVA+CACR_BCINVA+CACR_ICINVA)

arch/m68knommu/Kconfig

@@ -82,6 +82,9 @@ config COLDFIRE_SW_A7
 config HAVE_CACHE_SPLIT
 	bool
 
+config HAVE_CACHE_CB
+	bool
+
 source "init/Kconfig"
 
 source "kernel/Kconfig.freezer"
@@ -172,27 +175,32 @@ config M528x
 config M5307
 	bool "MCF5307"
 	select COLDFIRE_SW_A7
+	select HAVE_CACHE_CB
 	help
 	  Motorola ColdFire 5307 processor support.
 
 config M532x
 	bool "MCF532x"
+	select HAVE_CACHE_CB
 	help
 	  Freescale (Motorola) ColdFire 532x processor support.
 
 config M5407
 	bool "MCF5407"
 	select COLDFIRE_SW_A7
+	select HAVE_CACHE_CB
 	help
 	  Motorola ColdFire 5407 processor support.
 
 config M547x
 	bool "MCF547x"
+	select HAVE_CACHE_CB
 	help
 	  Freescale ColdFire 5470/5471/5472/5473/5474/5475 processor support.
 
 config M548x
 	bool "MCF548x"
+	select HAVE_CACHE_CB
 	help
 	  Freescale ColdFire 5480/5481/5482/5483/5484/5485 processor support.
 
@@ -279,7 +287,23 @@ config CACHE_BOTH
 	  Split the ColdFire CPU cache, and use half as an instruction cache
 	  and half as a data cache.
 endchoice
+endif
 
+if HAVE_CACHE_CB
+choice
+	prompt "Data cache mode"
+	default CACHE_WRITETHRU
+
+config CACHE_WRITETHRU
+	bool "Write-through"
+	help
+	  The ColdFire CPU cache is set into Write-through mode.
+
+config CACHE_COPYBACK
+	bool "Copy-back"
+	help
+	  The ColdFire CPU cache is set into Copy-back mode.
+endchoice
 endif
 
 comment "Platform"