IB/rdmavt: Consolidate dma ops in rdmavt.

This patch adds dma functions to rdmavt. The source is hfi1's version of
dma.c which will be removed by a subsequent hfi1 patch.

Reviewed-by: Ira Weiny <ira.weiny@intel.com>
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/infiniband/sw/rdmavt/Makefile

@@ -7,4 +7,4 @@
 #
 obj-$(CONFIG_INFINIBAND_RDMAVT) += rdmavt.o
 
-rdmavt-y := vt.o
+rdmavt-y := vt.o dma.o

drivers/infiniband/sw/rdmavt/dma.c

@@ -0,0 +1,184 @@
+/*
+ * Copyright(c) 2015 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
+};

drivers/infiniband/sw/rdmavt/dma.h

@@ -0,0 +1,53 @@
+#ifndef DEF_RDMAVTDMA_H
+#define DEF_RDMAVTDMA_H
+
+/*
+ * Copyright(c) 2015 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.
+ *
+ */
+
+extern struct ib_dma_mapping_ops rvt_default_dma_mapping_ops;
+
+#endif          /* DEF_RDMAVTDMA_H */

drivers/infiniband/sw/rdmavt/vt.c

@@ -69,6 +69,16 @@ int rvt_register_device(struct rvt_dev_info *rdi)
 	if (!rdi)
 		return -EINVAL;
 
+	/*
+	 * Drivers have the option to override anything in the ibdev that they
+	 * want to specifically handle. VT needs to check for things it supports
+	 * and if the driver wants to handle that functionality let it. We may
+	 * come up with a better mechanism that simplifies the code at some
+	 * point.
+	 */
+	rdi->ibdev.dma_ops =
+		rdi->ibdev.dma_ops ? : &rvt_default_dma_mapping_ops;
+
 	return ib_register_device(&rdi->ibdev, rdi->port_callback);
 }
 EXPORT_SYMBOL(rvt_register_device);

drivers/infiniband/sw/rdmavt/vt.h

@@ -49,5 +49,6 @@
  */
 
 #include <rdma/rdma_vt.h>
+#include "dma.h"
 
 #endif          /* DEF_RDMAVT_H */