rdma: SVCRDMA Transport Module

This file implements the RDMA transport module initialization and
termination logic and registers the transport sysctl variables.

Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Acked-by: Neil Brown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

1 files changed, 266 insertions, 0 deletions

diff --git a/net/sunrpc/xprtrdma/svc_rdma.c b/net/sunrpc/xprtrdma/svc_rdma.c
new file mode 100644
index 000000000000..88c0ca20bb1e
--- /dev/null
+++ b/net/sunrpc/xprtrdma/svc_rdma.c
@@ -0,0 +1,266 @@
+/*
+ * Copyright (c) 2005-2006 Network Appliance, 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 BSD-type
+ * 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 the Network Appliance, Inc. 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.
+ *
+ * Author: Tom Tucker <tom@opengridcomputing.com>
+ */
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/sysctl.h>
+#include <linux/sunrpc/clnt.h>
+#include <linux/sunrpc/sched.h>
+#include <linux/sunrpc/svc_rdma.h>
+
+#define RPCDBG_FACILITY RPCDBG_SVCXPRT
+
+/* RPC/RDMA parameters */
+unsigned int svcrdma_ord = RPCRDMA_ORD;
+static unsigned int min_ord = 1;
+static unsigned int max_ord = 4096;
+unsigned int svcrdma_max_requests = RPCRDMA_MAX_REQUESTS;
+static unsigned int min_max_requests = 4;
+static unsigned int max_max_requests = 16384;
+unsigned int svcrdma_max_req_size = RPCRDMA_MAX_REQ_SIZE;
+static unsigned int min_max_inline = 4096;
+static unsigned int max_max_inline = 65536;
+
+atomic_t rdma_stat_recv;
+atomic_t rdma_stat_read;
+atomic_t rdma_stat_write;
+atomic_t rdma_stat_sq_starve;
+atomic_t rdma_stat_rq_starve;
+atomic_t rdma_stat_rq_poll;
+atomic_t rdma_stat_rq_prod;
+atomic_t rdma_stat_sq_poll;
+atomic_t rdma_stat_sq_prod;
+
+/*
+ * This function implements reading and resetting an atomic_t stat
+ * variable through read/write to a proc file. Any write to the file
+ * resets the associated statistic to zero. Any read returns it's
+ * current value.
+ */
+static int read_reset_stat(ctl_table *table, int write,
+                           struct file *filp, void __user *buffer, size_t *lenp,
+                           loff_t *ppos)
+{
+        atomic_t *stat = (atomic_t *)table->data;
+
+        if (!stat)
+                return -EINVAL;
+
+        if (write)
+                atomic_set(stat, 0);
+        else {
+                char str_buf[32];
+                char *data;
+                int len = snprintf(str_buf, 32, "%d\n", atomic_read(stat));
+                if (len >= 32)
+                        return -EFAULT;
+                len = strlen(str_buf);
+                if (*ppos > len) {
+                        *lenp = 0;
+                        return 0;
+                }
+                data = &str_buf[*ppos];
+                len -= *ppos;
+                if (len > *lenp)
+                        len = *lenp;
+                if (len && copy_to_user(buffer, str_buf, len))
+                        return -EFAULT;
+                *lenp = len;
+                *ppos += len;
+        }
+        return 0;
+}
+
+static struct ctl_table_header *svcrdma_table_header;
+static ctl_table svcrdma_parm_table[] = {
+        {
+                .procname       = "max_requests",
+                .data           = &svcrdma_max_requests,
+                .maxlen         = sizeof(unsigned int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec_minmax,
+                .strategy       = &sysctl_intvec,
+                .extra1         = &min_max_requests,
+                .extra2         = &max_max_requests
+        },
+        {
+                .procname       = "max_req_size",
+                .data           = &svcrdma_max_req_size,
+                .maxlen         = sizeof(unsigned int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec_minmax,
+                .strategy       = &sysctl_intvec,
+                .extra1         = &min_max_inline,
+                .extra2         = &max_max_inline
+        },
+        {
+                .procname       = "max_outbound_read_requests",
+                .data           = &svcrdma_ord,
+                .maxlen         = sizeof(unsigned int),
+                .mode           = 0644,
+                .proc_handler   = &proc_dointvec_minmax,
+                .strategy       = &sysctl_intvec,
+                .extra1         = &min_ord,
+                .extra2         = &max_ord,
+        },
+
+        {
+                .procname       = "rdma_stat_read",
+                .data           = &rdma_stat_read,
+                .maxlen         = sizeof(atomic_t),
+                .mode           = 0644,
+                .proc_handler   = &read_reset_stat,
+        },
+        {
+                .procname       = "rdma_stat_recv",
+                .data           = &rdma_stat_recv,
+                .maxlen         = sizeof(atomic_t),
+                .mode           = 0644,
+                .proc_handler   = &read_reset_stat,
+        },
+        {
+                .procname       = "rdma_stat_write",
+                .data           = &rdma_stat_write,
+                .maxlen         = sizeof(atomic_t),
+                .mode           = 0644,
+                .proc_handler   = &read_reset_stat,
+        },
+        {
+                .procname       = "rdma_stat_sq_starve",
+                .data           = &rdma_stat_sq_starve,
+                .maxlen         = sizeof(atomic_t),
+                .mode           = 0644,
+                .proc_handler   = &read_reset_stat,
+        },
+        {
+                .procname       = "rdma_stat_rq_starve",
+                .data           = &rdma_stat_rq_starve,
+                .maxlen         = sizeof(atomic_t),
+                .mode           = 0644,
+                .proc_handler   = &read_reset_stat,
+        },
+        {
+                .procname       = "rdma_stat_rq_poll",
+                .data           = &rdma_stat_rq_poll,
+                .maxlen         = sizeof(atomic_t),
+                .mode           = 0644,
+                .proc_handler   = &read_reset_stat,
+        },
+        {
+                .procname       = "rdma_stat_rq_prod",
+                .data           = &rdma_stat_rq_prod,
+                .maxlen         = sizeof(atomic_t),
+                .mode           = 0644,
+                .proc_handler   = &read_reset_stat,
+        },
+        {
+                .procname       = "rdma_stat_sq_poll",
+                .data           = &rdma_stat_sq_poll,
+                .maxlen         = sizeof(atomic_t),
+                .mode           = 0644,
+                .proc_handler   = &read_reset_stat,
+        },
+        {
+                .procname       = "rdma_stat_sq_prod",
+                .data           = &rdma_stat_sq_prod,
+                .maxlen         = sizeof(atomic_t),
+                .mode           = 0644,
+                .proc_handler   = &read_reset_stat,
+        },
+        {
+                .ctl_name = 0,
+        },
+};
+
+static ctl_table svcrdma_table[] = {
+        {
+                .procname       = "svc_rdma",
+                .mode           = 0555,
+                .child          = svcrdma_parm_table
+        },
+        {
+                .ctl_name = 0,
+        },
+};
+
+static ctl_table svcrdma_root_table[] = {
+        {
+                .ctl_name       = CTL_SUNRPC,
+                .procname       = "sunrpc",
+                .mode           = 0555,
+                .child          = svcrdma_table
+        },
+        {
+                .ctl_name = 0,
+        },
+};
+
+void svc_rdma_cleanup(void)
+{
+        dprintk("SVCRDMA Module Removed, deregister RPC RDMA transport\n");
+        if (svcrdma_table_header) {
+                unregister_sysctl_table(svcrdma_table_header);
+                svcrdma_table_header = NULL;
+        }
+        svc_unreg_xprt_class(&svc_rdma_class);
+}
+
+int svc_rdma_init(void)
+{
+        dprintk("SVCRDMA Module Init, register RPC RDMA transport\n");
+        dprintk("\tsvcrdma_ord      : %d\n", svcrdma_ord);
+        dprintk("\tmax_requests     : %d\n", svcrdma_max_requests);
+        dprintk("\tsq_depth         : %d\n",
+                svcrdma_max_requests * RPCRDMA_SQ_DEPTH_MULT);
+        dprintk("\tmax_inline       : %d\n", svcrdma_max_req_size);
+        if (!svcrdma_table_header)
+                svcrdma_table_header =
+                        register_sysctl_table(svcrdma_root_table);
+
+        /* Register RDMA with the SVC transport switch */
+        svc_reg_xprt_class(&svc_rdma_class);
+        return 0;
+}
+MODULE_AUTHOR("Tom Tucker <tom@opengridcomputing.com>");
+MODULE_DESCRIPTION("SVC RDMA Transport");
+MODULE_LICENSE("Dual BSD/GPL");
+module_init(svc_rdma_init);
+module_exit(svc_rdma_cleanup);