[U-Boot] [v3] command/cache: Add flush command

[York Sun]

When we copy code/data to the main memory, we may need to flush the
cache if required by architecture. It uses the existing function
flush_cache. Syntax is

flush <addr> <size>

The addr and size are given in hexadecimal. Like memory command, there is
no sanity check for the parameters.

Signed-off-by: York Sun <yorksun at freescale.com>
---
Change since v2: rename flush_cache to flush

 README             |    5 ++++-
 common/cmd_cache.c |   26 ++++++++++++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/README b/README
index dc6b0b3..b2f80d6 100644
--- a/README
+++ b/README
@@ -809,6 +809,7 @@ The following options need to be configured:
 		CONFIG_CMD_BSP		* Board specific commands
 		CONFIG_CMD_BOOTD	  bootd
 		CONFIG_CMD_CACHE	* icache, dcache
+		CONFIG_CMD_CACHE_FLUSH	* flush cache by the address and range
 		CONFIG_CMD_CONSOLE	  coninfo
 		CONFIG_CMD_CRC32	* crc32
 		CONFIG_CMD_DATE		* support for RTC, date/time...
@@ -912,7 +913,9 @@ The following options need to be configured:
 		8260 (where accesses to the IMMR region must be
 		uncached), and it cannot be disabled on all other
 		systems where we (mis-) use the data cache to hold an
-		initial stack and some data.
+		initial stack and some data. The CONFIG_CMD_CACHE_FLUSH
+		macro enables flushing cache by the address and range to
+		maintain coherency if required by architecture.
 
 
 		XXX - this list needs to get updated!
diff --git a/common/cmd_cache.c b/common/cmd_cache.c
index 5512f92..c228e0c 100644
--- a/common/cmd_cache.c
+++ b/common/cmd_cache.c
@@ -120,3 +120,29 @@ U_BOOT_CMD(
 	"[on, off, flush]\n"
 	"    - enable, disable, or flush data (writethrough) cache"
 );
+
+#ifdef CONFIG_CMD_CACHE_FLUSH
+int do_flush_cache(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
+{
+	ulong addr, size;
+
+	switch (argc) {
+	case 3:
+		addr = simple_strtoul(argv[1], NULL, 16);
+		size = simple_strtoul(argv[2], NULL, 16);
+		flush_cache(addr, size);
+		break;
+	default:
+		return cmd_usage(cmdtp);
+	}
+	return 0;
+
+}
+
+U_BOOT_CMD(
+	flush,   3,   0,     do_flush_cache,
+	"flush cache for a range",
+	"<addr> <size>\n"
+	"    - flush cache for specificed range"
+);
+#endif
-- 
1.7.9.5