Initial import

1 files changed, 142 insertions, 0 deletions

diff --git a/arch/blackfin/kernel/dma-mapping.c b/arch/blackfin/kernel/dma-mapping.c
new file mode 100644
index 000000000..df437e52d
--- /dev/null
+++ b/arch/blackfin/kernel/dma-mapping.c
@@ -0,0 +1,142 @@
+/*
+ * Dynamic DMA mapping support
+ *
+ * Copyright 2005-2009 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2 or later
+ */
+
+#include <linux/types.h>
+#include <linux/gfp.h>
+#include <linux/string.h>
+#include <linux/spinlock.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
+#include <linux/export.h>
+#include <linux/bitmap.h>
+
+static spinlock_t dma_page_lock;
+static unsigned long *dma_page;
+static unsigned int dma_pages;
+static unsigned long dma_base;
+static unsigned long dma_size;
+static unsigned int dma_initialized;
+
+static void dma_alloc_init(unsigned long start, unsigned long end)
+{
+	spin_lock_init(&dma_page_lock);
+	dma_initialized = 0;
+
+	dma_page = (unsigned long *)__get_free_page(GFP_KERNEL);
+	memset(dma_page, 0, PAGE_SIZE);
+	dma_base = PAGE_ALIGN(start);
+	dma_size = PAGE_ALIGN(end) - PAGE_ALIGN(start);
+	dma_pages = dma_size >> PAGE_SHIFT;
+	memset((void *)dma_base, 0, DMA_UNCACHED_REGION);
+	dma_initialized = 1;
+
+	printk(KERN_INFO "%s: dma_page @ 0x%p - %d pages at 0x%08lx\n", __func__,
+	       dma_page, dma_pages, dma_base);
+}
+
+static inline unsigned int get_pages(size_t size)
+{
+	return ((size - 1) >> PAGE_SHIFT) + 1;
+}
+
+static unsigned long __alloc_dma_pages(unsigned int pages)
+{
+	unsigned long ret = 0, flags;
+	unsigned long start;
+
+	if (dma_initialized == 0)
+		dma_alloc_init(_ramend - DMA_UNCACHED_REGION, _ramend);
+
+	spin_lock_irqsave(&dma_page_lock, flags);
+
+	start = bitmap_find_next_zero_area(dma_page, dma_pages, 0, pages, 0);
+	if (start < dma_pages) {
+		ret = dma_base + (start << PAGE_SHIFT);
+		bitmap_set(dma_page, start, pages);
+	}
+	spin_unlock_irqrestore(&dma_page_lock, flags);
+	return ret;
+}
+
+static void __free_dma_pages(unsigned long addr, unsigned int pages)
+{
+	unsigned long page = (addr - dma_base) >> PAGE_SHIFT;
+	unsigned long flags;
+
+	if ((page + pages) > dma_pages) {
+		printk(KERN_ERR "%s: freeing outside range.\n", __func__);
+		BUG();
+	}
+
+	spin_lock_irqsave(&dma_page_lock, flags);
+	bitmap_clear(dma_page, page, pages);
+	spin_unlock_irqrestore(&dma_page_lock, flags);
+}
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+			 dma_addr_t *dma_handle, gfp_t gfp)
+{
+	void *ret;
+
+	ret = (void *)__alloc_dma_pages(get_pages(size));
+
+	if (ret) {
+		memset(ret, 0, size);
+		*dma_handle = virt_to_phys(ret);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL(dma_alloc_coherent);
+
+void
+dma_free_coherent(struct device *dev, size_t size, void *vaddr,
+		  dma_addr_t dma_handle)
+{
+	__free_dma_pages((unsigned long)vaddr, get_pages(size));
+}
+EXPORT_SYMBOL(dma_free_coherent);
+
+/*
+ * Streaming DMA mappings
+ */
+void __dma_sync(dma_addr_t addr, size_t size,
+		enum dma_data_direction dir)
+{
+	__dma_sync_inline(addr, size, dir);
+}
+EXPORT_SYMBOL(__dma_sync);
+
+int
+dma_map_sg(struct device *dev, struct scatterlist *sg_list, int nents,
+	   enum dma_data_direction direction)
+{
+	struct scatterlist *sg;
+	int i;
+
+	for_each_sg(sg_list, sg, nents, i) {
+		sg->dma_address = (dma_addr_t) sg_virt(sg);
+		__dma_sync(sg_dma_address(sg), sg_dma_len(sg), direction);
+	}
+
+	return nents;
+}
+EXPORT_SYMBOL(dma_map_sg);
+
+void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg_list,
+			    int nelems, enum dma_data_direction direction)
+{
+	struct scatterlist *sg;
+	int i;
+
+	for_each_sg(sg_list, sg, nelems, i) {
+		sg->dma_address = (dma_addr_t) sg_virt(sg);
+		__dma_sync(sg_dma_address(sg), sg_dma_len(sg), direction);
+	}
+}
+EXPORT_SYMBOL(dma_sync_sg_for_device);