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+/*
+ * Software iWARP device driver for Linux
+ *
+ * Authors: Animesh Trivedi <atr@zurich.ibm.com>
+ * Bernard Metzler <bmt@zurich.ibm.com>
+ *
+ * Copyright (c) 2008-2011, IBM Corporation
+ *
+ * This software is available to you under a choice of one of two
+ * licenses. You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * BSD license below:
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * - Neither the name of IBM nor the names of its contributors may be
+ * used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+#include <linux/scatterlist.h>
+#include <linux/gfp.h>
+#include <rdma/ib_verbs.h>
+
+#include "siw.h"
+#include "siw_verbs.h"
+
+/*
+ * DMA mapping/address translation functions.
+ * Used to populate siw private DMA mapping functions of
+ * struct ib_dma_mapping_ops in struct ib_dev - see rdma/ib_verbs.h
+ */
+
+static int siw_mapping_error(struct ib_device *dev, u64 dma_addr)
+{
+ return dma_addr == 0;
+}
+
+static u64 siw_dma_map_single(struct ib_device *dev, void *kva, size_t size,
+ enum dma_data_direction dir)
+{
+ /* siw uses kernel virtual addresses for data transfer */
+ return (u64) kva;
+}
+
+static void siw_dma_unmap_single(struct ib_device *dev,
+ u64 addr, size_t size,
+ enum dma_data_direction dir)
+{
+ /* NOP */
+}
+
+static u64 siw_dma_map_page(struct ib_device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction dir)
+{
+ u64 kva = 0;
+
+ BUG_ON(!valid_dma_direction(dir));
+
+ if (offset + size <= PAGE_SIZE) {
+ kva = (u64) page_address(page);
+ if (kva)
+ kva += offset;
+ }
+ return kva;
+}
+
+static void siw_dma_unmap_page(struct ib_device *dev,
+ u64 addr, size_t size,
+ enum dma_data_direction dir)
+{
+ /* NOP */
+}
+
+static int siw_map_sg(struct ib_device *dev, struct scatterlist *sgl,
+ int n_sge, enum dma_data_direction dir)
+{
+ struct scatterlist *sg;
+ int i;
+
+ BUG_ON(!valid_dma_direction(dir));
+
+ /* This is just a validity check */
+ for_each_sg(sgl, sg, n_sge, i)
+ if (page_address(sg_page(sg)) == NULL)
+ return 0;
+
+ return n_sge;
+}
+
+static void siw_unmap_sg(struct ib_device *dev, struct scatterlist *sgl,
+ int n_sge, enum dma_data_direction dir)
+{
+ /* NOP */
+}
+
+static u64 siw_dma_address(struct ib_device *dev, struct scatterlist *sg)
+{
+ u64 kva = (u64) page_address(sg_page(sg));
+
+ if (kva)
+ kva += sg->offset;
+
+ return kva;
+}
+
+static unsigned int siw_dma_len(struct ib_device *dev,
+ struct scatterlist *sg)
+{
+ return sg_dma_len(sg);
+}
+
+static void siw_sync_single_for_cpu(struct ib_device *dev, u64 addr,
+ size_t size, enum dma_data_direction dir)
+{
+ /* NOP */
+}
+
+static void siw_sync_single_for_device(struct ib_device *dev, u64 addr,
+ size_t size,
+ enum dma_data_direction dir)
+{
+ /* NOP */
+}
+
+static void *siw_dma_alloc_coherent(struct ib_device *dev, size_t size,
+ u64 *dma_addr, gfp_t flag)
+{
+ struct page *page;
+ void *kva = NULL;
+
+ page = alloc_pages(flag, get_order(size));
+ if (page)
+ kva = page_address(page);
+ if (dma_addr)
+ *dma_addr = (u64)kva;
+
+ return kva;
+}
+
+static void siw_dma_free_coherent(struct ib_device *dev, size_t size,
+ void *kva, u64 dma_addr)
+{
+ free_pages((unsigned long) kva, get_order(size));
+}
+
+struct ib_dma_mapping_ops siw_dma_mapping_ops = {
+ .mapping_error = siw_mapping_error,
+ .map_single = siw_dma_map_single,
+ .unmap_single = siw_dma_unmap_single,
+ .map_page = siw_dma_map_page,
+ .unmap_page = siw_dma_unmap_page,
+ .map_sg = siw_map_sg,
+ .unmap_sg = siw_unmap_sg,
+ .dma_address = siw_dma_address,
+ .dma_len = siw_dma_len,
+ .sync_single_for_cpu = siw_sync_single_for_cpu,
+ .sync_single_for_device = siw_sync_single_for_device,
+ .alloc_coherent = siw_dma_alloc_coherent,
+ .free_coherent = siw_dma_free_coherent
+};