[U-Boot] [PATCH 03/26 v2][NEXT] ARM (ARM926ejs): add data cache support, tested on magnesium and tx25 board

Heiko Schocher
2010-09-17T11:10:30Z

Enable "cache" command on tx25 and magnesium board and test performance.

Test 1: Loading 127 MB of data from NAND flash into RAM:

Instr. Cache off on on
Data Cache off off on
--------------------------------------------------
magnesium 32,6s 22,5s 30s = x 1,09
tx25 (29MB only) 9,69s 5,05s 8,16s = x 1,19

Test 2: uncompressing a gzipped image from RAM to RAM
(size compressed: 6.5 MiB, uncompressed: 35 MiB):

Instr. Cache off on on
Data Cache off off on
--------------------------------------------------
magnesium 4,25s 2,08s 1,72s = x 2,47
tx25 4,82s 2,04s 1,84s = x 2,62

Portions of this work were supported by funding from
the CE Linux Forum.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>
Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Alessandro Rubini <rubini@gnudd.com>
---
arch/arm/lib/cache.c | 6 ++++++
include/configs/imx27lite-common.h | 1 +
include/configs/tx25.h | 1 +
3 files changed, 8 insertions(+), 0 deletions(-)

diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c
index 61ee9d3..b36fd24 100644
--- a/arch/arm/lib/cache.c
+++ b/arch/arm/lib/cache.c
@@ -32,5 +32,11 @@ void flush_cache (unsigned long dummy1, unsigned long dummy2)

arm1136_cache_flush();
#endif
+#ifdef CONFIG_ARM926EJS
+ /* test and clean, page 2-23 of arm926ejs manual */
+ asm("0: mrc p15, 0, r15, c7, c10, 3\n\t" "bne 0b\n" : : : "memory");
+ /* disable write buffer as well (page 2-22) */
+ asm("mcr p15, 0, %0, c7, c10, 4" : : "r" (0));
+#endif
return;
}
diff --git a/include/configs/imx27lite-common.h b/include/configs/imx27lite-common.h
index 1da8602..33550ba 100644
--- a/include/configs/imx27lite-common.h
+++ b/include/configs/imx27lite-common.h
@@ -188,6 +188,7 @@
*/
#include <config_cmd_default.h>
#define CONFIG_CMD_ASKENV
+#define CONFIG_CMD_CACHE
#define CONFIG_CMD_DHCP
#define CONFIG_CMD_DIAG
#define CONFIG_CMD_FAT
diff --git a/include/configs/tx25.h b/include/configs/tx25.h
index c8188ca..013aa35 100644
--- a/include/configs/tx25.h
+++ b/include/configs/tx25.h
@@ -131,6 +131,7 @@
/* U-Boot commands */
#include <config_cmd_default.h>
#define CONFIG_CMD_NAND
+#define CONFIG_CMD_CACHE

/*
* Ethernet
--
1.6.2.5