ARM: cache: add an empty stub function for invalidate/flush dcache

Since some driver like ohci, lcd used dcache functions. But some ARM
cpu don't implement the invalidate_dcache_range()/flush_dcache_range()
functions.

To avoid compiling errors this patch adds an weak empty stub function
for all ARM cpu in arch/arm/lib/cache.c.
And ARM cpu still can implemnt its own cache functions on the cpu folder.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
Reviewed-by: York Sun <yorksun@freescale.com>

1 files changed, 9 insertions, 0 deletions

diff --git a/arch/arm/lib/cache.c b/arch/arm/lib/cache.c
index 74cfde6..bc48f53 100644
--- a/arch/arm/lib/cache.c
+++ b/arch/arm/lib/cache.c
@@ -53,6 +53,15 @@ __weak void enable_caches(void)
 	puts("WARNING: Caches not enabled\n");
 }
 
+__weak void invalidate_dcache_range(unsigned long start, unsigned long stop)
+{
+	/* An empty stub, real implementation should be in platform code */
+}
+__weak void flush_dcache_range(unsigned long start, unsigned long stop)
+{
+	/* An empty stub, real implementation should be in platform code */
+}
+
 #ifdef CONFIG_SYS_NONCACHED_MEMORY
 /*
  * Reserve one MMU section worth of address space below the malloc() area that