Blackfin: split cache handling out of dma_memcpy()

Creating a new dma_memcpy() function that skips all cache checks allows us
to use the function in very early init where the cache is not yet setup.

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

lib_blackfin/string.c

@@ -134,7 +134,7 @@ int strncmp(const char *cs, const char *ct, size_t count)
  * Perhaps we should detect that ?  Nowhere do we actually
  * use dma memcpy for those types of lengths though ...
  */
-static void *dma_memcpy(void *dst, const void *src, size_t count)
+void dma_memcpy_nocache(void *dst, const void *src, size_t count)
 {
 	/* Scratchpad cannot be a DMA source or destination */
 	if (((unsigned long)src >= L1_SRAM_SCRATCH &&
@@ -143,10 +143,9 @@ static void *dma_memcpy(void *dst, const void *src, size_t count)
 	     (unsigned long)dst < L1_SRAM_SCRATCH_END))
 		hang();
 
-	if (dcache_status())
-		blackfin_dcache_flush_range(src, src + count);
-
-	bfin_write_MDMA_D0_IRQ_STATUS(DMA_DONE | DMA_ERR);
+	bfin_write_MDMA_S0_CONFIG(0);
+	bfin_write_MDMA_D0_CONFIG(0);
+	bfin_write_MDMA_D0_IRQ_STATUS(DMA_RUN | DMA_DONE | DMA_ERR);
 
 	/* Copy sram functions from sdram to sram */
 	/* Setup destination start address */
@@ -165,13 +164,23 @@ static void *dma_memcpy(void *dst, const void *src, size_t count)
 
 	/* Enable source DMA */
 	bfin_write_MDMA_S0_CONFIG(DMAEN);
-	SSYNC();
 
 	bfin_write_MDMA_D0_CONFIG(WNR | DMAEN);
+	SSYNC();
 
 	while (bfin_read_MDMA_D0_IRQ_STATUS() & DMA_RUN)
-		bfin_write_MDMA_D0_IRQ_STATUS(bfin_read_MDMA_D0_IRQ_STATUS() | DMA_DONE | DMA_ERR);
-	bfin_write_MDMA_D0_IRQ_STATUS(bfin_read_MDMA_D0_IRQ_STATUS() | DMA_DONE | DMA_ERR);
+		continue;
+
+	bfin_write_MDMA_D0_IRQ_STATUS(bfin_read_MDMA_D0_IRQ_STATUS() | DMA_RUN | DMA_DONE | DMA_ERR);
+	bfin_write_MDMA_D0_CONFIG(0);
+	bfin_write_MDMA_S0_CONFIG(0);
+}
+void *dma_memcpy(void *dst, const void *src, size_t count)
+{
+	if (dcache_status())
+		blackfin_dcache_flush_range(src, src + count);
+
+	dma_memcpy_nocache(dst, src, count);
 
 	if (icache_status())
 		blackfin_icache_flush_range(dst, dst + count);