1 files changed, 252 insertions, 0 deletions
diff --git a/arch/tile/kernel/pci-dma.c b/arch/tile/kernel/pci-dma.c
new file mode 100644
index 00000000..b3ed19f8
--- /dev/null
+++ b/arch/tile/kernel/pci-dma.c
@@ -0,0 +1,252 @@
+/*
+ * Copyright 2010 Tilera Corporation. All Rights Reserved.
+ *
+ *   This program is free software; you can redistribute it and/or
+ *   modify it under the terms of the GNU General Public License
+ *   as published by the Free Software Foundation, version 2.
+ *
+ *   This program is distributed in the hope that it will be useful, but
+ *   WITHOUT ANY WARRANTY; without even the implied warranty of
+ *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ *   NON INFRINGEMENT.  See the GNU General Public License for
+ *   more details.
+ */
+
+#include <linux/mm.h>
+#include <linux/dma-mapping.h>
+#include <linux/vmalloc.h>
+#include <linux/export.h>
+#include <asm/tlbflush.h>
+#include <asm/homecache.h>
+
+/* Generic DMA mapping functions: */
+
+/*
+ * Allocate what Linux calls "coherent" memory, which for us just
+ * means uncached.
+ */
+void *dma_alloc_coherent(struct device *dev,
+			 size_t size,
+			 dma_addr_t *dma_handle,
+			 gfp_t gfp)
+{
+	u64 dma_mask = dev->coherent_dma_mask ?: DMA_BIT_MASK(32);
+	int node = dev_to_node(dev);
+	int order = get_order(size);
+	struct page *pg;
+	dma_addr_t addr;
+
+	gfp |= __GFP_ZERO;
+
+	/*
+	 * By forcing NUMA node 0 for 32-bit masks we ensure that the
+	 * high 32 bits of the resulting PA will be zero.  If the mask
+	 * size is, e.g., 24, we may still not be able to guarantee a
+	 * suitable memory address, in which case we will return NULL.
+	 * But such devices are uncommon.
+	 */
+	if (dma_mask <= DMA_BIT_MASK(32))
+		node = 0;
+
+	pg = homecache_alloc_pages_node(node, gfp, order, PAGE_HOME_UNCACHED);
+	if (pg == NULL)
+		return NULL;
+
+	addr = page_to_phys(pg);
+	if (addr + size > dma_mask) {
+		homecache_free_pages(addr, order);
+		return NULL;
+	}
+
+	*dma_handle = addr;
+	return page_address(pg);
+}
+EXPORT_SYMBOL(dma_alloc_coherent);
+
+/*
+ * Free memory that was allocated with dma_alloc_coherent.
+ */
+void dma_free_coherent(struct device *dev, size_t size,
+		  void *vaddr, dma_addr_t dma_handle)
+{
+	homecache_free_pages((unsigned long)vaddr, get_order(size));
+}
+EXPORT_SYMBOL(dma_free_coherent);
+
+/*
+ * The map routines "map" the specified address range for DMA
+ * accesses.  The memory belongs to the device after this call is
+ * issued, until it is unmapped with dma_unmap_single.
+ *
+ * We don't need to do any mapping, we just flush the address range
+ * out of the cache and return a DMA address.
+ *
+ * The unmap routines do whatever is necessary before the processor
+ * accesses the memory again, and must be called before the driver
+ * touches the memory.  We can get away with a cache invalidate if we
+ * can count on nothing having been touched.
+ */
+
+/* Flush a PA range from cache page by page. */
+static void __dma_map_pa_range(dma_addr_t dma_addr, size_t size)
+{
+	struct page *page = pfn_to_page(PFN_DOWN(dma_addr));
+	size_t bytesleft = PAGE_SIZE - (dma_addr & (PAGE_SIZE - 1));
+
+	while ((ssize_t)size > 0) {
+		/* Flush the page. */
+		homecache_flush_cache(page++, 0);
+
+		/* Figure out if we need to continue on the next page. */
+		size -= bytesleft;
+		bytesleft = PAGE_SIZE;
+	}
+}
+
+/*
+ * dma_map_single can be passed any memory address, and there appear
+ * to be no alignment constraints.
+ *
+ * There is a chance that the start of the buffer will share a cache
+ * line with some other data that has been touched in the meantime.
+ */
+dma_addr_t dma_map_single(struct device *dev, void *ptr, size_t size,
+	       enum dma_data_direction direction)
+{
+	dma_addr_t dma_addr = __pa(ptr);
+
+	BUG_ON(!valid_dma_direction(direction));
+	WARN_ON(size == 0);
+
+	__dma_map_pa_range(dma_addr, size);
+
+	return dma_addr;
+}
+EXPORT_SYMBOL(dma_map_single);
+
+void dma_unmap_single(struct device *dev, dma_addr_t dma_addr, size_t size,
+		 enum dma_data_direction direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+}
+EXPORT_SYMBOL(dma_unmap_single);
+
+int dma_map_sg(struct device *dev, struct scatterlist *sglist, int nents,
+	   enum dma_data_direction direction)
+{
+	struct scatterlist *sg;
+	int i;
+
+	BUG_ON(!valid_dma_direction(direction));
+
+	WARN_ON(nents == 0 || sglist->length == 0);
+
+	for_each_sg(sglist, sg, nents, i) {
+		sg->dma_address = sg_phys(sg);
+		__dma_map_pa_range(sg->dma_address, sg->length);
+	}
+
+	return nents;
+}
+EXPORT_SYMBOL(dma_map_sg);
+
+void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nhwentries,
+	     enum dma_data_direction direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+}
+EXPORT_SYMBOL(dma_unmap_sg);
+
+dma_addr_t dma_map_page(struct device *dev, struct page *page,
+			unsigned long offset, size_t size,
+			enum dma_data_direction direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+
+	BUG_ON(offset + size > PAGE_SIZE);
+	homecache_flush_cache(page, 0);
+
+	return page_to_pa(page) + offset;
+}
+EXPORT_SYMBOL(dma_map_page);
+
+void dma_unmap_page(struct device *dev, dma_addr_t dma_address, size_t size,
+	       enum dma_data_direction direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+}
+EXPORT_SYMBOL(dma_unmap_page);
+
+void dma_sync_single_for_cpu(struct device *dev, dma_addr_t dma_handle,
+			     size_t size, enum dma_data_direction direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+}
+EXPORT_SYMBOL(dma_sync_single_for_cpu);
+
+void dma_sync_single_for_device(struct device *dev, dma_addr_t dma_handle,
+				size_t size, enum dma_data_direction direction)
+{
+	unsigned long start = PFN_DOWN(dma_handle);
+	unsigned long end = PFN_DOWN(dma_handle + size - 1);
+	unsigned long i;
+
+	BUG_ON(!valid_dma_direction(direction));
+	for (i = start; i <= end; ++i)
+		homecache_flush_cache(pfn_to_page(i), 0);
+}
+EXPORT_SYMBOL(dma_sync_single_for_device);
+
+void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg, int nelems,
+		    enum dma_data_direction direction)
+{
+	BUG_ON(!valid_dma_direction(direction));
+	WARN_ON(nelems == 0 || sg[0].length == 0);
+}
+EXPORT_SYMBOL(dma_sync_sg_for_cpu);
+
+/*
+ * Flush and invalidate cache for scatterlist.
+ */
+void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sglist,
+			    int nelems, enum dma_data_direction direction)
+{
+	struct scatterlist *sg;
+	int i;
+
+	BUG_ON(!valid_dma_direction(direction));
+	WARN_ON(nelems == 0 || sglist->length == 0);
+
+	for_each_sg(sglist, sg, nelems, i) {
+		dma_sync_single_for_device(dev, sg->dma_address,
+					   sg_dma_len(sg), direction);
+	}
+}
+EXPORT_SYMBOL(dma_sync_sg_for_device);
+
+void dma_sync_single_range_for_cpu(struct device *dev, dma_addr_t dma_handle,
+				   unsigned long offset, size_t size,
+				   enum dma_data_direction direction)
+{
+	dma_sync_single_for_cpu(dev, dma_handle + offset, size, direction);
+}
+EXPORT_SYMBOL(dma_sync_single_range_for_cpu);
+
+void dma_sync_single_range_for_device(struct device *dev,
+				      dma_addr_t dma_handle,
+				      unsigned long offset, size_t size,
+				      enum dma_data_direction direction)
+{
+	dma_sync_single_for_device(dev, dma_handle + offset, size, direction);
+}
+EXPORT_SYMBOL(dma_sync_single_range_for_device);
+
+/*
+ * dma_alloc_noncoherent() returns non-cacheable memory, so there's no
+ * need to do any flushing here.
+ */
+void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
+		    enum dma_data_direction direction)
+{
+}
+EXPORT_SYMBOL(dma_cache_sync);