Blackfin: fix dcache handling when doing dma memcpy's

Our dcache invalidate function doesn't just invalidate, it also flushes.
So rename the function accordingly and fix the dma_memcpy() function so it
doesn't inadvertently corrupt the data destination.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

cpu/blackfin/cache.S

@@ -39,7 +39,7 @@ ENTRY(_blackfin_dcache_flush_range)
 	RTS;
 ENDPROC(_blackfin_dcache_flush_range)
 
-ENTRY(_blackfin_dcache_invalidate_range)
+ENTRY(_blackfin_dcache_flush_invalidate_range)
 	R2 = -32;
 	R2 = R0 & R2;
 	P0 = R2;
@@ -58,4 +58,4 @@ ENTRY(_blackfin_dcache_invalidate_range)
 	FLUSHINV[P0];
 	SSYNC;
 	RTS;
-ENDPROC(_blackfin_dcache_invalidate_range)
+ENDPROC(_blackfin_dcache_flush_invalidate_range)

include/asm-blackfin/blackfin_local.h

@@ -58,7 +58,7 @@ extern u_long get_sclk(void);
 
 extern void blackfin_icache_flush_range(const void *, const void *);
 extern void blackfin_dcache_flush_range(const void *, const void *);
-extern void blackfin_dcache_invalidate_range(const void *, const void *);
+extern void blackfin_dcache_flush_invalidate_range(const void *, const void *);
 
 /* Use DMA to move data from on chip to external memory.  While this is
  * required for only L1 instruction (it is not directly readable by the

lib_blackfin/string.c

@@ -175,19 +175,22 @@ void dma_memcpy_nocache(void *dst, const void *src, size_t count)
 	bfin_write_MDMA_D0_CONFIG(0);
 	bfin_write_MDMA_S0_CONFIG(0);
 }
+/* We should do a dcache invalidate on the destination after the dma, but since
+ * we lack such hardware capability, we'll flush/invalidate the destination
+ * before the dma and bank on the idea that u-boot is single threaded.
+ */
 void *dma_memcpy(void *dst, const void *src, size_t count)
 {
-	if (dcache_status())
+	if (dcache_status()) {
 		blackfin_dcache_flush_range(src, src + count);
+		blackfin_dcache_flush_invalidate_range(dst, dst + count);
+	}
 
 	dma_memcpy_nocache(dst, src, count);
 
 	if (icache_status())
 		blackfin_icache_flush_range(dst, dst + count);
 
-	if (dcache_status())
-		blackfin_dcache_invalidate_range(dst, dst + count);
-
 	return dst;
 }