[U-Boot] [PATCH] IXP425: make cmd_go handle caches correctly Part 1/1

[Stefan Althoefer <stefan.althoefer@web.de>]

IXP425: make cmd_go handle caches correctly

This patch adds icache_invalidate() and dcache_flush() to
cpu/ixp/cpu.c.

Also it adds do_go_exec() which is called from do_go().
This private implementation performs cache handling
before jumping into the code.

Without this cache handling, you will jump into stale
code if you download a program several times.

Signed-off-by: Stefan Althoefer <stefan.althoefer@web.de>
---

>
> Coding style: please use TABs for indentation.
>

Sorry for the spaces.

BTW: In function calls: Is the space between function name
are opening bracket desired or not? Seems this is handled
very inconsistent.

-- Stefan

 cpu/ixp/cpu.c |   32 ++++++++++++++++++++++++++++++++
 1 files changed, 32 insertions(+), 0 deletions(-)

diff --git a/cpu/ixp/cpu.c b/cpu/ixp/cpu.c
index 27872fb..9035d98 100644
--- a/cpu/ixp/cpu.c
+++ b/cpu/ixp/cpu.c
@@ -171,6 +171,22 @@ int icache_status (void)
 	return (i & 0x1000);
 }

+void icache_invalidate (void)
+{
+	register u32 i;
+
+	/* FIXME: Required to check if icache is enabled before we do this? */
+
+	/* invalidate I-cache (i is ignored)*/
+	i = 0;
+	asm ("mcr p15, 0, %0, c7, c5, 0": :"r" (i));
+
+	/* cpwait */
+	asm ("mrc  p15,0,%0,c2,c0,0;\
+	    mov  %0,%0;\
+	    sub  pc,pc,#4" : : "r" (i) );
+}
+
 /* we will never enable dcache, because we have to setup MMU first */
 void dcache_enable (void)
 {
@@ -187,6 +203,11 @@ int dcache_status (void)
 	return 0;					/* always off */
 }

+void dcache_flush (void)
+{
+	return;
+}
+
 /* FIXME */
 /*
 void pci_init(void)
@@ -195,6 +216,17 @@ void pci_init(void)
 }
 */

+/* With IXP (and ARM generally) we need to handle caches to avoid
+   stale data. */
+unsigned long do_go_exec (ulong (*entry)(int, char *[]), int argc, char *argv[])
+{
+	dcache_flush ();
+	icache_invalidate ();
+
+	return entry (argc, argv);
+}
+
+
 #ifdef CONFIG_BOOTCOUNT_LIMIT

 void bootcount_store (ulong a)
-- 
1.5.6