linux-stable/drivers/infiniband/sw/rxe/rxe_dma.c
Moni Shoua 8700e3e7c4 Soft RoCE driver
Soft RoCE (RXE) - The software RoCE driver

ib_rxe implements the RDMA transport and registers to the RDMA core
device as a kernel verbs provider. It also implements the packet IO
layer. On the other hand ib_rxe registers to the Linux netdev stack
as a udp encapsulating protocol, in that case RDMA, for sending and
receiving packets over any Ethernet device.  This yields a RDMA
transport over the UDP/Ethernet network layer forming a RoCEv2
compatible device.

The configuration procedure of the Soft RoCE drivers requires
binding to any existing Ethernet network device. This is done with
/sys interface.

A userspace Soft RoCE library (librxe) provides user applications
the ability to run with Soft RoCE devices.  The use of rxe verbs ins
user space requires the inclusion of librxe as a device specifics
plug-in to libibverbs. librxe is packaged separately.

Architecture:

     +-----------------------------------------------------------+
     |                          Application                      |
     +-----------------------------------------------------------+
                            +-----------------------------------+
                            |             libibverbs            |
User                        +-----------------------------------+
                            +----------------+ +----------------+
                            | librxe         | | HW RoCE lib    |
                            +----------------+ +----------------+
+---------------------------------------------------------------+
     +--------------+                           +------------+
     | Sockets      |                           | RDMA ULP   |
     +--------------+                           +------------+
     +--------------+                  +---------------------+
     | TCP/IP       |                  | ib_core             |
     +--------------+                  +---------------------+
                             +------------+ +----------------+
Kernel                       | ib_rxe     | | HW RoCE driver |
                             +------------+ +----------------+
     +------------------------------------+
     | NIC driver                         |
     +------------------------------------+

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     +-----------------------------------------------------------+
     |                          Application                      |
     +-----------------------------------------------------------+
                            +-----------------------------------+
                            |             libibverbs            |
User                        +-----------------------------------+
                            +----------------+ +----------------+
                            | librxe         | | HW RoCE lib    |
                            +----------------+ +----------------+
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     +--------------+                           +------------+
     | Sockets      |                           | RDMA ULP   |
     +--------------+                           +------------+
     +--------------+                  +---------------------+
     | TCP/IP       |                  | ib_core             |
     +--------------+                  +---------------------+
                             +------------+ +----------------+
Kernel                       | ib_rxe     | | HW RoCE driver |
                             +------------+ +----------------+
     +------------------------------------+
     | NIC driver                         |
     +------------------------------------+
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Soft RoCE resources:

[1[ https://github.com/SoftRoCE/librxe-dev librxe - source code in
Github
[2] https://github.com/SoftRoCE/rxe-dev/wiki/rxe-dev:-Home - Soft RoCE
Wiki page
[3] https://github.com/SoftRoCE/librxe-dev - Soft RoCE userspace library

Signed-off-by: Kamal Heib <kamalh@mellanox.com>
Signed-off-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: Moni Shoua <monis@mellanox.com>
Reviewed-by: Haggai Eran <haggaie@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-04 11:13:12 -04:00

166 lines
4.4 KiB
C

/*
* 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 (uintptr_t)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 = (uintptr_t)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 = (uintptr_t)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 = (uintptr_t)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
};