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 a407bca..2f16386 100644
--- a/lib_avr32/board.c
+++ b/lib_avr32/board.c
@@ -76,6 +76,50 @@
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 @@
/* 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 @@
timer_init();
mem_malloc_init();
malloc_bin_reloc();
+ dma_alloc_init();
board_init_info();
flash_init();