lib: Introduce priority array area manager

This introduces a infrastructure for management of linear priority
areas. Priority order in an array matters, however order of items inside
a priority group does not matter.

As an initial implementation, L-sort algorithm is used. It is quite
trivial. More advanced algorithm called P-sort will be introduced as a
follow-up. The infrastructure is prepared for other algos.

Alongside this, a testing module is introduced as well.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 76 insertions, 0 deletions

diff --git a/include/linux/parman.h b/include/linux/parman.h
new file mode 100644
index 000000000000..3c8cccc7d4da
--- /dev/null
+++ b/include/linux/parman.h
@@ -0,0 +1,76 @@
+/*
+ * include/linux/parman.h - Manager for linear priority array areas
+ * Copyright (c) 2017 Mellanox Technologies. All rights reserved.
+ * Copyright (c) 2017 Jiri Pirko <jiri@mellanox.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the names of the copyright holders nor the names of its
+ *    contributors may be used to endorse or promote products derived from
+ *    this software without specific prior written permission.
+ *
+ * Alternatively, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") version 2 as published by the Free
+ * Software Foundation.
+ *
+ * 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.
+ */
+
+#ifndef _PARMAN_H
+#define _PARMAN_H
+
+#include <linux/list.h>
+
+enum parman_algo_type {
+	PARMAN_ALGO_TYPE_LSORT,
+};
+
+struct parman_item {
+	struct list_head list;
+	unsigned long index;
+};
+
+struct parman_prio {
+	struct list_head list;
+	struct list_head item_list;
+	unsigned long priority;
+};
+
+struct parman_ops {
+	unsigned long base_count;
+	unsigned long resize_step;
+	int (*resize)(void *priv, unsigned long new_count);
+	void (*move)(void *priv, unsigned long from_index,
+		     unsigned long to_index, unsigned long count);
+	enum parman_algo_type algo;
+};
+
+struct parman;
+
+struct parman *parman_create(const struct parman_ops *ops, void *priv);
+void parman_destroy(struct parman *parman);
+void parman_prio_init(struct parman *parman, struct parman_prio *prio,
+		      unsigned long priority);
+void parman_prio_fini(struct parman_prio *prio);
+int parman_item_add(struct parman *parman, struct parman_prio *prio,
+		    struct parman_item *item);
+void parman_item_remove(struct parman *parman, struct parman_prio *prio,
+			struct parman_item *item);
+
+#endif