Blackfin: pass RETX to Linux

[u-boot] / lib_blackfin / string.c

diff --git a/lib_blackfin/string.c b/lib_blackfin/string.c
index 6887c93decd7174e0c3757171cfec2ff1d21ec11..36eecdff4c5b498f176ce705928494231f1aa9f1 100644 (file)
--- a/lib_blackfin/string.c
+++ b/lib_blackfin/string.c
@@ -1,7 +1,7 @@
 /*
  * U-boot - string.c Contains library routines.
  *
- * Copyright (c) 2005-2007 Analog Devices Inc.
+ * Copyright (c) 2005-2008 Analog Devices Inc.
  *
  * (C) Copyright 2000-2004
  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
@@ -130,12 +130,22 @@ int strncmp(const char *cs, const char *ct, size_t count)
 # define bfin_write_MDMA_D0_IRQ_STATUS bfin_write_MDMA1_D0_IRQ_STATUS
 # define bfin_read_MDMA_D0_IRQ_STATUS  bfin_read_MDMA1_D0_IRQ_STATUS
 #endif
-static void *dma_memcpy(void *dst, const void *src, size_t count)
+/* This version misbehaves for count values of 0 and 2^16+.
+ * Perhaps we should detect that ?  Nowhere do we actually
+ * use dma memcpy for those types of lengths though ...
+ */
+void dma_memcpy_nocache(void *dst, const void *src, size_t count)
 {
-       if (dcache_status())
-               blackfin_dcache_flush_range(src, src + count);
+       /* Scratchpad cannot be a DMA source or destination */
+       if (((unsigned long)src >= L1_SRAM_SCRATCH &&
+            (unsigned long)src < L1_SRAM_SCRATCH_END) ||
+           ((unsigned long)dst >= L1_SRAM_SCRATCH &&
+            (unsigned long)dst < L1_SRAM_SCRATCH_END))
+               hang();
 
-       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 */
@@ -154,20 +164,33 @@ 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);
+}
+/* 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()) {
+               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;
 }