[PATCH rdma-next 23/29] IB/rxe: Dummy DMA callbacks for RXE device

Moni Shoua
2016-06-02T16:57:31Z

Implement Soft RoCE DMA operations. Since Soft RoCE is not tied to a
hardware but to a software device , DMA is meaningless and operations
do no implement real DMA.

Signed-off-by: Kamal Heib <kamalh-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Signed-off-by: Amir Vadai <amirv-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Signed-off-by: Moni Shoua <monis-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Reviewed-by: Haggai Eran <haggaie-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
drivers/infiniband/hw/rxe/rxe_dma.c | 166 ++++++++++++++++++++++++++++++++++++
1 file changed, 166 insertions(+)
create mode 100644 drivers/infiniband/hw/rxe/rxe_dma.c

diff --git a/drivers/infiniband/hw/rxe/rxe_dma.c b/drivers/infiniband/hw/rxe/rxe_dma.c
new file mode 100644
index 0000000..f080bc5
--- /dev/null
+++ b/drivers/infiniband/hw/rxe/rxe_dma.c
@@ -0,0 +1,166 @@
+/*
+ * Copyright (c) 2016 Mellanox Technologies Ltd. All rights reserved.
+ * Copyright (c) 2015 System Fabric Works, Inc. All rights reserved.
+ *
+ * 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
+ * OpenIB.org 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.
+ *
+ * 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 "rxe.h"
+#include "rxe_loc.h"
+
+#define DMA_BAD_ADDER ((u64)0)
+
+static int rxe_mapping_error(struct ib_device *dev, u64 dma_addr)
+{
+ return dma_addr == DMA_BAD_ADDER;
+}
+
+static u64 rxe_dma_map_single(struct ib_device *dev,
+ void *cpu_addr, size_t size,
+ enum dma_data_direction direction)
+{
+ WARN_ON(!valid_dma_direction(direction));
+ return (u64)cpu_addr;
+}
+
+static void rxe_dma_unmap_single(struct ib_device *dev,
+ u64 addr, size_t size,
+ enum dma_data_direction direction)
+{
+ WARN_ON(!valid_dma_direction(direction));
+}
+
+static u64 rxe_dma_map_page(struct ib_device *dev,
+ struct page *page,
+ unsigned long offset,
+ size_t size, enum dma_data_direction direction)
+{
+ u64 addr;
+
+ WARN_ON(!valid_dma_direction(direction));
+
+ if (offset + size > PAGE_SIZE) {
+ addr = DMA_BAD_ADDER;
+ goto done;
+ }
+
+ addr = (u64)page_address(page);
+ if (addr)
+ addr += offset;
+
+done:
+ return addr;
+}
+
+static void rxe_dma_unmap_page(struct ib_device *dev,
+ u64 addr, size_t size,
+ enum dma_data_direction direction)
+{
+ WARN_ON(!valid_dma_direction(direction));
+}
+
+static int rxe_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;
+
+ WARN_ON(!valid_dma_direction(direction));
+
+ 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 rxe_unmap_sg(struct ib_device *dev,
+ struct scatterlist *sg, int nents,
+ enum dma_data_direction direction)
+{
+ WARN_ON(!valid_dma_direction(direction));
+}
+
+static void rxe_sync_single_for_cpu(struct ib_device *dev,
+ u64 addr,
+ size_t size, enum dma_data_direction dir)
+{
+}
+
+static void rxe_sync_single_for_device(struct ib_device *dev,
+ u64 addr,
+ size_t size, enum dma_data_direction dir)
+{
+}
+
+static void *rxe_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 rxe_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 rxe_dma_mapping_ops = {
+ .mapping_error = rxe_mapping_error,
+ .map_single = rxe_dma_map_single,
+ .unmap_single = rxe_dma_unmap_single,
+ .map_page = rxe_dma_map_page,
+ .unmap_page = rxe_dma_unmap_page,
+ .map_sg = rxe_map_sg,
+ .unmap_sg = rxe_unmap_sg,
+ .sync_single_for_cpu = rxe_sync_single_for_cpu,
+ .sync_single_for_device = rxe_sync_single_for_device,
+ .alloc_coherent = rxe_dma_alloc_coherent,
+ .free_coherent = rxe_dma_free_coherent
+};
--
1.8.3.1