IB/usnic: Add Cisco VIC low-level hardware driver

This adds a driver that allows userspace to use UD-like QPs over a
proprietary Cisco transport with Cisco's Virtual Interface Cards (VICs),
including VIC 1240 and 1280 cards.

Signed-off-by: Upinder Malhi <umalhi@cisco.com>
Signed-off-by: Christian Benvenuti <benve@cisco.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 125 insertions, 0 deletions

diff --git a/drivers/infiniband/hw/usnic/usnic_transport.c b/drivers/infiniband/hw/usnic/usnic_transport.c
new file mode 100644
index 000000000000..723bd6c3a8f8
--- /dev/null
+++ b/drivers/infiniband/hw/usnic/usnic_transport.c
@@ -0,0 +1,125 @@
+/*
+ * Copyright (c) 2013, Cisco Systems, Inc. All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * 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 <linux/bitmap.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+
+#include "usnic_transport.h"
+#include "usnic_log.h"
+
+/* ROCE */
+static unsigned long *roce_bitmap;
+static u16 roce_next_port = 1;
+#define ROCE_BITMAP_SZ ((1 << (8 /*CHAR_BIT*/ * sizeof(u16)))/8 /*CHAR BIT*/)
+static DEFINE_SPINLOCK(roce_bitmap_lock);
+
+static const char *transport_to_str(enum usnic_transport_type type)
+{
+	switch (type) {
+	case USNIC_TRANSPORT_UNKNOWN:
+		return "Unknown";
+	case USNIC_TRANSPORT_ROCE_CUSTOM:
+		return "roce custom";
+	case USNIC_TRANSPORT_MAX:
+		return "Max?";
+	default:
+		return "Not known";
+	}
+}
+
+/*
+ * reserve a port number.  if "0" specified, we will try to pick one
+ * starting at roce_next_port.  roce_next_port will take on the values
+ * 1..4096
+ */
+u16 usnic_transport_rsrv_port(enum usnic_transport_type type, u16 port_num)
+{
+	if (type == USNIC_TRANSPORT_ROCE_CUSTOM) {
+		spin_lock(&roce_bitmap_lock);
+		if (!port_num) {
+			port_num = bitmap_find_next_zero_area(roce_bitmap,
+						ROCE_BITMAP_SZ,
+						roce_next_port /* start */,
+						1 /* nr */,
+						0 /* align */);
+			roce_next_port = (port_num & 4095) + 1;
+		} else if (test_bit(port_num, roce_bitmap)) {
+			usnic_err("Failed to allocate port for %s\n",
+					transport_to_str(type));
+			spin_unlock(&roce_bitmap_lock);
+			goto out_fail;
+		}
+		bitmap_set(roce_bitmap, port_num, 1);
+		spin_unlock(&roce_bitmap_lock);
+	} else {
+		usnic_err("Failed to allocate port - transport %s unsupported\n",
+				transport_to_str(type));
+		goto out_fail;
+	}
+
+	usnic_dbg("Allocating port %hu for %s\n", port_num,
+			transport_to_str(type));
+	return port_num;
+
+out_fail:
+	return 0;
+}
+
+void usnic_transport_unrsrv_port(enum usnic_transport_type type, u16 port_num)
+{
+	if (type == USNIC_TRANSPORT_ROCE_CUSTOM) {
+		spin_lock(&roce_bitmap_lock);
+		if (!port_num) {
+			usnic_err("Unreserved unvalid port num 0 for %s\n",
+					transport_to_str(type));
+			goto out_roce_custom;
+		}
+
+		if (!test_bit(port_num, roce_bitmap)) {
+			usnic_err("Unreserving invalid %hu for %s\n",
+					port_num,
+					transport_to_str(type));
+			goto out_roce_custom;
+		}
+		bitmap_clear(roce_bitmap, port_num, 1);
+		usnic_dbg("Freeing port %hu for %s\n", port_num,
+				transport_to_str(type));
+out_roce_custom:
+		spin_unlock(&roce_bitmap_lock);
+	} else {
+		usnic_err("Freeing invalid port %hu for %d\n", port_num, type);
+	}
+}
+
+int usnic_transport_init(void)
+{
+	roce_bitmap = kzalloc(ROCE_BITMAP_SZ, GFP_KERNEL);
+	if (!roce_bitmap) {
+		usnic_err("Failed to allocate bit map");
+		return -ENOMEM;
+	}
+
+	/* Do not ever allocate bit 0, hence set it here */
+	bitmap_set(roce_bitmap, 0, 1);
+	return 0;
+}
+
+void usnic_transport_fini(void)
+{
+	kfree(roce_bitmap);
+}