AVR32: Implement simple DMA memory allocator

Implement dma_alloc_coherent() which returns cache-aligned
uncacheable memory.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>

diff --git a/lib_avr32/board.c b/lib_avr32/board.c
index a407bcad14d7ab637cca5dfa71432ade6cfea97d..2f16386c76835b5bc1c349fcfcfaa2c4c53f4f30 100644 (file)
--- a/lib_avr32/board.c
+++ b/lib_avr32/board.c
@@ -76,6 +76,50 @@ void *sbrk(ptrdiff_t increment)
        return ((void *)old);
 }
 
+#ifdef CFG_DMA_ALLOC_LEN
+#include <asm/cacheflush.h>
+#include <asm/io.h>
+
+static unsigned long dma_alloc_start;
+static unsigned long dma_alloc_end;
+static unsigned long dma_alloc_brk;
+
+static void dma_alloc_init(void)
+{
+       unsigned long monitor_addr;
+
+       monitor_addr = CFG_MONITOR_BASE + gd->reloc_off;
+       dma_alloc_end = monitor_addr - CFG_MALLOC_LEN;
+       dma_alloc_start = dma_alloc_end - CFG_DMA_ALLOC_LEN;
+       dma_alloc_brk = dma_alloc_start;
+
+       printf("DMA: Using memory from 0x%08lx to 0x%08lx\n",
+              dma_alloc_start, dma_alloc_end);
+
+       dcache_invalidate_range(cached(dma_alloc_start),
+                               dma_alloc_end - dma_alloc_start);
+}
+
+void *dma_alloc_coherent(size_t len, unsigned long *handle)
+{
+       unsigned long paddr = dma_alloc_brk;
+
+       if (dma_alloc_brk + len > dma_alloc_end)
+               return NULL;
+
+       dma_alloc_brk = ((paddr + len + CFG_DCACHE_LINESZ - 1)
+                        & ~(CFG_DCACHE_LINESZ - 1));
+
+       *handle = paddr;
+       return uncached(paddr);
+}
+#else
+static inline void dma_alloc_init(void)
+{
+
+}
+#endif
+
 static int init_baudrate(void)
 {
        char tmp[64];
@@ -179,6 +223,12 @@ void board_init_f(ulong board_type)
        /* Reserve memory for malloc() */
        addr -= CFG_MALLOC_LEN;
 
+#ifdef CFG_DMA_ALLOC_LEN
+       /* Reserve DMA memory (must be cache aligned) */
+       addr &= ~(CFG_DCACHE_LINESZ - 1);
+       addr -= CFG_DMA_ALLOC_LEN;
+#endif
+
        /* Allocate a Board Info struct on a word boundary */
        addr -= sizeof(bd_t);
        addr &= ~3UL;
@@ -258,6 +308,7 @@ void board_init_r(gd_t *new_gd, ulong dest_addr)
        timer_init();
        mem_malloc_init();
        malloc_bin_reloc();
+       dma_alloc_init();
        board_init_info();
        flash_init();