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-rw-r--r--arch/microblaze/kernel/dma.c156
1 files changed, 156 insertions, 0 deletions
diff --git a/arch/microblaze/kernel/dma.c b/arch/microblaze/kernel/dma.c
new file mode 100644
index 00000000000..b1084974fcc
--- /dev/null
+++ b/arch/microblaze/kernel/dma.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (C) 2009-2010 PetaLogix
+ * Copyright (C) 2006 Benjamin Herrenschmidt, IBM Corporation
+ *
+ * Provide default implementations of the DMA mapping callbacks for
+ * directly mapped busses.
+ */
+
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/dma-debug.h>
+#include <asm/bug.h>
+#include <asm/cacheflush.h>
+
+/*
+ * Generic direct DMA implementation
+ *
+ * This implementation supports a per-device offset that can be applied if
+ * the address at which memory is visible to devices is not 0. Platform code
+ * can set archdata.dma_data to an unsigned long holding the offset. By
+ * default the offset is PCI_DRAM_OFFSET.
+ */
+static inline void __dma_sync_page(unsigned long paddr, unsigned long offset,
+ size_t size, enum dma_data_direction direction)
+{
+ switch (direction) {
+ case DMA_TO_DEVICE:
+ flush_dcache_range(paddr + offset, paddr + offset + size);
+ break;
+ case DMA_FROM_DEVICE:
+ invalidate_dcache_range(paddr + offset, paddr + offset + size);
+ break;
+ default:
+ BUG();
+ }
+}
+
+static unsigned long get_dma_direct_offset(struct device *dev)
+{
+ if (dev)
+ return (unsigned long)dev->archdata.dma_data;
+
+ return PCI_DRAM_OFFSET; /* FIXME Not sure if is correct */
+}
+
+#define NOT_COHERENT_CACHE
+
+static void *dma_direct_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flag)
+{
+#ifdef NOT_COHERENT_CACHE
+ return consistent_alloc(flag, size, dma_handle);
+#else
+ void *ret;
+ struct page *page;
+ int node = dev_to_node(dev);
+
+ /* ignore region specifiers */
+ flag &= ~(__GFP_HIGHMEM);
+
+ page = alloc_pages_node(node, flag, get_order(size));
+ if (page == NULL)
+ return NULL;
+ ret = page_address(page);
+ memset(ret, 0, size);
+ *dma_handle = virt_to_phys(ret) + get_dma_direct_offset(dev);
+
+ return ret;
+#endif
+}
+
+static void dma_direct_free_coherent(struct device *dev, size_t size,
+ void *vaddr, dma_addr_t dma_handle)
+{
+#ifdef NOT_COHERENT_CACHE
+ consistent_free(vaddr);
+#else
+ free_pages((unsigned long)vaddr, get_order(size));
+#endif
+}
+
+static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
+ int nents, enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+ struct scatterlist *sg;
+ int i;
+
+ /* FIXME this part of code is untested */
+ for_each_sg(sgl, sg, nents, i) {
+ sg->dma_address = sg_phys(sg) + get_dma_direct_offset(dev);
+ sg->dma_length = sg->length;
+ __dma_sync_page(page_to_phys(sg_page(sg)), sg->offset,
+ sg->length, direction);
+ }
+
+ return nents;
+}
+
+static void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sg,
+ int nents, enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+}
+
+static int dma_direct_dma_supported(struct device *dev, u64 mask)
+{
+ return 1;
+}
+
+static inline dma_addr_t dma_direct_map_page(struct device *dev,
+ struct page *page,
+ unsigned long offset,
+ size_t size,
+ enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+ __dma_sync_page(page_to_phys(page), offset, size, direction);
+ return page_to_phys(page) + offset + get_dma_direct_offset(dev);
+}
+
+static inline void dma_direct_unmap_page(struct device *dev,
+ dma_addr_t dma_address,
+ size_t size,
+ enum dma_data_direction direction,
+ struct dma_attrs *attrs)
+{
+/* There is not necessary to do cache cleanup
+ *
+ * phys_to_virt is here because in __dma_sync_page is __virt_to_phys and
+ * dma_address is physical address
+ */
+ __dma_sync_page(dma_address, 0 , size, direction);
+}
+
+struct dma_map_ops dma_direct_ops = {
+ .alloc_coherent = dma_direct_alloc_coherent,
+ .free_coherent = dma_direct_free_coherent,
+ .map_sg = dma_direct_map_sg,
+ .unmap_sg = dma_direct_unmap_sg,
+ .dma_supported = dma_direct_dma_supported,
+ .map_page = dma_direct_map_page,
+ .unmap_page = dma_direct_unmap_page,
+};
+EXPORT_SYMBOL(dma_direct_ops);
+
+/* Number of entries preallocated for DMA-API debugging */
+#define PREALLOC_DMA_DEBUG_ENTRIES (1 << 16)
+
+static int __init dma_init(void)
+{
+ dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
+
+ return 0;
+}
+fs_initcall(dma_init);