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path: root/drivers/infiniband/sw/rdmavt/dma.c
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Diffstat (limited to 'drivers/infiniband/sw/rdmavt/dma.c')
-rw-r--r--drivers/infiniband/sw/rdmavt/dma.c184
1 files changed, 184 insertions, 0 deletions
diff --git a/drivers/infiniband/sw/rdmavt/dma.c b/drivers/infiniband/sw/rdmavt/dma.c
new file mode 100644
index 000000000..33076a5ee
--- /dev/null
+++ b/drivers/infiniband/sw/rdmavt/dma.c
@@ -0,0 +1,184 @@
+/*
+ * Copyright(c) 2016 Intel Corporation.
+ *
+ * This file is provided under a dual BSD/GPLv2 license. When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * 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. See the GNU
+ * General Public License for more details.
+ *
+ * BSD LICENSE
+ *
+ * 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 Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+#include <linux/types.h>
+#include <linux/scatterlist.h>
+#include <rdma/ib_verbs.h>
+
+#include "dma.h"
+
+#define BAD_DMA_ADDRESS ((u64)0)
+
+/*
+ * The following functions implement driver specific replacements
+ * for the ib_dma_*() functions.
+ *
+ * These functions return kernel virtual addresses instead of
+ * device bus addresses since the driver uses the CPU to copy
+ * data instead of using hardware DMA.
+ */
+
+static int rvt_mapping_error(struct ib_device *dev, u64 dma_addr)
+{
+ return dma_addr == BAD_DMA_ADDRESS;
+}
+
+static u64 rvt_dma_map_single(struct ib_device *dev, void *cpu_addr,
+ size_t size, enum dma_data_direction direction)
+{
+ if (WARN_ON(!valid_dma_direction(direction)))
+ return BAD_DMA_ADDRESS;
+
+ return (u64)cpu_addr;
+}
+
+static void rvt_dma_unmap_single(struct ib_device *dev, u64 addr, size_t size,
+ enum dma_data_direction direction)
+{
+ /* This is a stub, nothing to be done here */
+}
+
+static u64 rvt_dma_map_page(struct ib_device *dev, struct page *page,
+ unsigned long offset, size_t size,
+ enum dma_data_direction direction)
+{
+ u64 addr;
+
+ if (WARN_ON(!valid_dma_direction(direction)))
+ return BAD_DMA_ADDRESS;
+
+ if (offset + size > PAGE_SIZE)
+ return BAD_DMA_ADDRESS;
+
+ addr = (u64)page_address(page);
+ if (addr)
+ addr += offset;
+
+ return addr;
+}
+
+static void rvt_dma_unmap_page(struct ib_device *dev, u64 addr, size_t size,
+ enum dma_data_direction direction)
+{
+ /* This is a stub, nothing to be done here */
+}
+
+static int rvt_map_sg(struct ib_device *dev, struct scatterlist *sgl,
+ int nents, enum dma_data_direction direction)
+{
+ struct scatterlist *sg;
+ u64 addr;
+ int i;
+ int ret = nents;
+
+ if (WARN_ON(!valid_dma_direction(direction)))
+ return 0;
+
+ for_each_sg(sgl, sg, nents, i) {
+ addr = (u64)page_address(sg_page(sg));
+ if (!addr) {
+ ret = 0;
+ break;
+ }
+ sg->dma_address = addr + sg->offset;
+#ifdef CONFIG_NEED_SG_DMA_LENGTH
+ sg->dma_length = sg->length;
+#endif
+ }
+ return ret;
+}
+
+static void rvt_unmap_sg(struct ib_device *dev,
+ struct scatterlist *sg, int nents,
+ enum dma_data_direction direction)
+{
+ /* This is a stub, nothing to be done here */
+}
+
+static void rvt_sync_single_for_cpu(struct ib_device *dev, u64 addr,
+ size_t size, enum dma_data_direction dir)
+{
+}
+
+static void rvt_sync_single_for_device(struct ib_device *dev, u64 addr,
+ size_t size,
+ enum dma_data_direction dir)
+{
+}
+
+static void *rvt_dma_alloc_coherent(struct ib_device *dev, size_t size,
+ u64 *dma_handle, gfp_t flag)
+{
+ struct page *p;
+ void *addr = NULL;
+
+ p = alloc_pages(flag, get_order(size));
+ if (p)
+ addr = page_address(p);
+ if (dma_handle)
+ *dma_handle = (u64)addr;
+ return addr;
+}
+
+static void rvt_dma_free_coherent(struct ib_device *dev, size_t size,
+ void *cpu_addr, u64 dma_handle)
+{
+ free_pages((unsigned long)cpu_addr, get_order(size));
+}
+
+struct ib_dma_mapping_ops rvt_default_dma_mapping_ops = {
+ .mapping_error = rvt_mapping_error,
+ .map_single = rvt_dma_map_single,
+ .unmap_single = rvt_dma_unmap_single,
+ .map_page = rvt_dma_map_page,
+ .unmap_page = rvt_dma_unmap_page,
+ .map_sg = rvt_map_sg,
+ .unmap_sg = rvt_unmap_sg,
+ .sync_single_for_cpu = rvt_sync_single_for_cpu,
+ .sync_single_for_device = rvt_sync_single_for_device,
+ .alloc_coherent = rvt_dma_alloc_coherent,
+ .free_coherent = rvt_dma_free_coherent
+};