--- /dev/null
+/*
+ * net/sched/sch_tegra.c
+ *
+ * Tegra Network Device Queue (TEGRA) packet scheduling algorithm.
+ *
+ * Copyright (C) 2015 NVIDIA Corporation. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/rtnetlink.h>
+#include <linux/moduleparam.h>
+#include <linux/atomic.h>
+#include <net/pkt_sched.h>
+#include <net/sch_generic.h>
+
+#define SCH_TEGRA_PR_INFO\
+ switch (sch_tegra_debug) case 1: pr_info\
+
+#define PFIFO_FAST_PRIV_SIZEOF\
+ (\
+ sizeof(u32) \
+ + 3 * sizeof(struct sk_buff_head)\
+ )\
+
+#define OZ_ETHERTYPE 0x892e
+
+static int sch_tegra_debug;
+module_param(sch_tegra_debug, int, 0644);
+
+static int sch_tegra_enable = 1;
+module_param(sch_tegra_enable, int, 0644);
+
+static unsigned long sch_tegra_pfifo_fast_dequeue_bits;
+module_param(sch_tegra_pfifo_fast_dequeue_bits, ulong, 0644);
+
+static unsigned long sch_tegra_pfifo_fast_dequeue_jiffies0;
+module_param(sch_tegra_pfifo_fast_dequeue_jiffies0, ulong, 0644);
+
+static unsigned long sch_tegra_pfifo_fast_dequeue_jiffies1;
+module_param(sch_tegra_pfifo_fast_dequeue_jiffies1, ulong, 0644);
+
+static unsigned long sch_tegra_pfifo_fast_dequeue_bits_per_sec;
+module_param(sch_tegra_pfifo_fast_dequeue_bits_per_sec, ulong, 0644);
+
+static unsigned long sch_tegra_pfifo_fast_dequeue_bits_per_sec_threshold
+ = 100000000UL;
+module_param(sch_tegra_pfifo_fast_dequeue_bits_per_sec_threshold, ulong, 0644);
+
+/* Counter of how many sch_tegra_pfifo_fast qdisc(s) have high
+ * priority packet(s)
+ */
+static atomic_t sch_tegra_pfifo_fast_highest_prio = ATOMIC_INIT(0);
+
+/*
+ * Private data for a sch_tegra_pfifo_fast scheduler containing:
+ * - bitmap + queue for the highest-priority band
+ * (reserved for real-time tegra devices, such as audio stream to
+ * network gaming controller)
+ * - pfifo_fast private data
+ * (sch_tegra_pfifo_fast subclasses pfifo_fast)
+ */
+struct sch_tegra_pfifo_fast_priv {
+ /* this must be at the beginning of the structure for
+ * subclassing to work
+ */
+ char pfifo_fast_priv[PFIFO_FAST_PRIV_SIZEOF];
+ /* bitmap for highest priority traffic */
+ u32 bitmap_highest_prio;
+ /* queue for the highest priority traffic
+ * - such as audio stream to network gaming controller
+ * - more...
+ */
+ struct sk_buff_head q_highest_prio;
+};
+
+static struct sk_buff *
+sch_tegra_pfifo_fast_dequeue_datarate(struct sk_buff *skb)
+{
+ unsigned long delta;
+
+ if (skb)
+ sch_tegra_pfifo_fast_dequeue_bits += skb->len * 8;
+ if (!sch_tegra_pfifo_fast_dequeue_jiffies0)
+ sch_tegra_pfifo_fast_dequeue_jiffies0 = jiffies;
+ sch_tegra_pfifo_fast_dequeue_jiffies1 = jiffies;
+ delta = sch_tegra_pfifo_fast_dequeue_jiffies1
+ - sch_tegra_pfifo_fast_dequeue_jiffies0;
+ if (delta < 10)
+ return skb;
+ if ((delta > msecs_to_jiffies(1000)) ||
+ (sch_tegra_pfifo_fast_dequeue_bits / (delta + 1)
+ > ULONG_MAX / HZ)) {
+ sch_tegra_pfifo_fast_dequeue_bits
+ /= (delta + 1);
+ sch_tegra_pfifo_fast_dequeue_jiffies0
+ = jiffies;
+ sch_tegra_pfifo_fast_dequeue_jiffies1
+ = sch_tegra_pfifo_fast_dequeue_jiffies0;
+ delta = 0;
+ }
+ sch_tegra_pfifo_fast_dequeue_bits_per_sec
+ = sch_tegra_pfifo_fast_dequeue_bits / (delta + 1) * HZ;
+
+ return skb;
+}
+
+
+static int
+sch_tegra_pfifo_fast_enqueue
+ (struct sk_buff *skb, struct Qdisc *qdisc)
+{
+ SCH_TEGRA_PR_INFO("%s\n", __func__);
+
+ /* subclass sch_tegra_pfifo_fast_ops -> enqueue() */
+ if (!sch_tegra_enable)
+ goto sch_tegra_disabled;
+ if ((skb->protocol == htons(OZ_ETHERTYPE)) &&
+ (skb_queue_len(&qdisc->q) < qdisc_dev(qdisc)->tx_queue_len)) {
+ struct sch_tegra_pfifo_fast_priv *priv = qdisc_priv(qdisc);
+ struct sk_buff_head *list = &priv->q_highest_prio;
+
+ SCH_TEGRA_PR_INFO("%s: OZ_ETHERTYPE\n", __func__);
+
+ if (!(priv->bitmap_highest_prio & 1)) {
+ atomic_inc(&sch_tegra_pfifo_fast_highest_prio);
+ priv->bitmap_highest_prio |= 1;
+ }
+ qdisc->q.qlen++;
+ return __qdisc_enqueue_tail(skb, qdisc, list);
+ }
+sch_tegra_disabled:
+
+ /* superclass pfifo_fast_ops -> enqueue() */
+ if (pfifo_fast_ops.enqueue)
+ return pfifo_fast_ops.enqueue(skb, qdisc);
+ return 0;
+
+}
+
+static struct sk_buff *
+sch_tegra_pfifo_fast_dequeue
+ (struct Qdisc *qdisc)
+{
+ struct sch_tegra_pfifo_fast_priv *priv = qdisc_priv(qdisc);
+ int i;
+
+ SCH_TEGRA_PR_INFO("%s\n", __func__);
+
+ /* subclass sch_tegra_pfifo_fast_ops -> dequeue() */
+ if (priv->bitmap_highest_prio & 1) {
+ struct sk_buff_head *list = &priv->q_highest_prio;
+ struct sk_buff *skb = __qdisc_dequeue_head(qdisc, list);
+
+ qdisc->q.qlen--;
+ if (skb_queue_empty(list)) {
+ atomic_dec(&sch_tegra_pfifo_fast_highest_prio);
+ priv->bitmap_highest_prio &= ~1;
+ }
+
+ return skb;
+ }
+ if (!sch_tegra_enable)
+ goto sch_tegra_disabled;
+ i = atomic_read(&sch_tegra_pfifo_fast_highest_prio);
+ if (i > 0) {
+ SCH_TEGRA_PR_INFO("%s:"
+ " sch_tegra_pfifo_fast_highest_prio (%d) > 0"
+ " - do not dequeue lower priority packet(s)\n",
+ __func__,
+ i);
+ return NULL;
+ }
+ sch_tegra_pfifo_fast_dequeue_datarate(NULL);
+ if (sch_tegra_pfifo_fast_dequeue_bits_per_sec
+ >= sch_tegra_pfifo_fast_dequeue_bits_per_sec_threshold) {
+ SCH_TEGRA_PR_INFO("%s:"
+ " sch_tegra_pfifo_fast_dequeue_bits_per_sec"
+ " (%ld) >="
+ " sch_tegra_pfifo_fast_dequeue_bits_per_sec_threshold"
+ " (%ld)"
+ " - do not dequeue lower priority packet(s)\n",
+ __func__,
+ sch_tegra_pfifo_fast_dequeue_bits_per_sec,
+ sch_tegra_pfifo_fast_dequeue_bits_per_sec_threshold);
+ return NULL;
+ }
+sch_tegra_disabled:
+
+ /* superclass pfifo_fast_ops -> dequeue() */
+ if (pfifo_fast_ops.dequeue)
+ return sch_tegra_pfifo_fast_dequeue_datarate
+ (pfifo_fast_ops.dequeue(qdisc));
+ return NULL;
+
+}
+
+static struct sk_buff *
+sch_tegra_pfifo_fast_peek
+ (struct Qdisc *qdisc)
+{
+ struct sch_tegra_pfifo_fast_priv *priv = qdisc_priv(qdisc);
+
+ SCH_TEGRA_PR_INFO("%s\n", __func__);
+
+ /* subclass sch_tegra_pfifo_fast_ops -> peek() */
+ if (priv->bitmap_highest_prio & 1) {
+ struct sk_buff_head *list = &priv->q_highest_prio;
+
+ return skb_peek(list);
+ }
+
+ /* superclass pfifo_fast_ops -> peek() */
+ if (pfifo_fast_ops.peek)
+ return pfifo_fast_ops.peek(qdisc);
+ return NULL;
+
+}
+
+static int
+sch_tegra_pfifo_fast_init
+ (struct Qdisc *qdisc, struct nlattr *opt)
+{
+ int err = -1;
+ struct sch_tegra_pfifo_fast_priv *priv = qdisc_priv(qdisc);
+
+ SCH_TEGRA_PR_INFO("%s\n", __func__);
+
+ /* superclass pfifo_fast_ops -> init() */
+ if (pfifo_fast_ops.init)
+ err = pfifo_fast_ops.init(qdisc, opt);
+
+ /* override flag set by superclass pfifo_fast_ops -> init() */
+ qdisc->flags &= ~TCQ_F_CAN_BYPASS;
+
+ /* subclass sch_tegra_pfifo_fast_ops -> init() */
+ priv->bitmap_highest_prio = 0;
+ skb_queue_head_init(&priv->q_highest_prio);
+
+ return 0;
+
+}
+
+static void
+sch_tegra_pfifo_fast_reset
+ (struct Qdisc *qdisc)
+{
+ struct sch_tegra_pfifo_fast_priv *priv = qdisc_priv(qdisc);
+
+ SCH_TEGRA_PR_INFO("%s\n", __func__);
+
+ /* subclass sch_tegra_pfifo_fast_ops -> reset() */
+ __qdisc_reset_queue(qdisc, &priv->q_highest_prio);
+ if (priv->bitmap_highest_prio) {
+ atomic_dec(&sch_tegra_pfifo_fast_highest_prio);
+ priv->bitmap_highest_prio = 0;
+ }
+ qdisc->qstats.backlog = 0;
+ qdisc->q.qlen = 0;
+
+ /* superclass pfifo_fast_ops -> reset() */
+ if (pfifo_fast_ops.reset)
+ pfifo_fast_ops.reset(qdisc);
+ return;
+
+}
+
+static int
+sch_tegra_pfifo_fast_dump
+ (struct Qdisc *qdisc, struct sk_buff *skb)
+{
+ SCH_TEGRA_PR_INFO("%s\n", __func__);
+
+ /* subclass sch_tegra_pfifo_fast_ops -> dump() */
+
+ /* superclass pfifo_fast_ops -> dump() */
+ if (pfifo_fast_ops.dump)
+ return pfifo_fast_ops.dump(qdisc, skb);
+ return 0;
+
+}
+
+/*static*/ struct Qdisc_ops sch_tegra_pfifo_fast_ops __read_mostly = {
+ .id = "tegra_pfifo",
+ .priv_size = sizeof(struct sch_tegra_pfifo_fast_priv),
+ .enqueue = sch_tegra_pfifo_fast_enqueue,
+ .dequeue = sch_tegra_pfifo_fast_dequeue,
+ .peek = sch_tegra_pfifo_fast_peek,
+ .init = sch_tegra_pfifo_fast_init,
+ .reset = sch_tegra_pfifo_fast_reset,
+ .dump = sch_tegra_pfifo_fast_dump,
+ .owner = THIS_MODULE,
+};
+EXPORT_SYMBOL(sch_tegra_pfifo_fast_ops);
+
+static int __init sch_tegra_init(void)
+{
+ int err;
+
+ pr_info("%s\n", __func__);
+
+ err = register_qdisc(&sch_tegra_pfifo_fast_ops);
+ if (err < 0) {
+ pr_err("%s: failed to register qdisc: %d\n", __func__, err);
+ return -ENODEV;
+ }
+
+ return 0;
+
+}
+
+static void __exit sch_tegra_exit(void)
+{
+ pr_info("%s\n", __func__);
+
+ unregister_qdisc(&sch_tegra_pfifo_fast_ops);
+
+}
+
+module_init(sch_tegra_init);
+module_exit(sch_tegra_exit);
+
+MODULE_LICENSE("GPL v2");
projects / sojka / nv-tegra / linux-3.10.git / commitdiff