Re: [alsa-devel] [very-RFC 5/8] Add TSN machinery to drive the traffic from a shim over the network

clearing up netdev-typo -H

On Sun, Jun 12, 2016 at 12:22:18AM +0200, Henrik Austad wrote:

From: Henrik Austad haustad@cisco.com

In short summary:

• tsn_core.c is the main driver of tsn, all new links go through here and all data to/form the shims are handled here core also manages the shim-interface.

• tsn_configfs.c is the API to userspace. TSN is driven from userspace and a link is created, configured, enabled, disabled and removed purely from userspace. All attributes requried must be determined by userspace, preferrably via IEEE 1722.1 (discovery and enumeration).

• tsn_header.c small part that handles the actual header of the frames we send. Kept out of core for cleanliness.

• tsn_net.c handles operations towards the networking layer.

The current driver is under development. This means that from the moment it is enabled with a shim, it will send traffic, either 0-traffic (frames of reserved length but with payload 0) or actual traffic. This will change once the driver stabilizes.

For more detail, see Documentation/networking/tsn/

Cc: "David S. Miller" davem@davemloft.net Signed-off-by: Henrik Austad haustad@cisco.com

---

net/Makefile | 1 + net/tsn/Makefile | 6 + net/tsn/tsn_configfs.c | 623 +++++++++++++++++++++++++++++++ net/tsn/tsn_core.c | 975 +++++++++++++++++++++++++++++++++++++++++++++++++ net/tsn/tsn_header.c | 203 ++++++++++ net/tsn/tsn_internal.h | 383 +++++++++++++++++++ net/tsn/tsn_net.c | 403 ++++++++++++++++++++ 7 files changed, 2594 insertions(+) create mode 100644 net/tsn/Makefile create mode 100644 net/tsn/tsn_configfs.c create mode 100644 net/tsn/tsn_core.c create mode 100644 net/tsn/tsn_header.c create mode 100644 net/tsn/tsn_internal.h create mode 100644 net/tsn/tsn_net.c

diff --git a/net/Makefile b/net/Makefile index bdd1455..c15482e 100644 --- a/net/Makefile +++ b/net/Makefile @@ -79,3 +79,4 @@ ifneq ($(CONFIG_NET_L3_MASTER_DEV),) obj-y += l3mdev/ endif obj-$(CONFIG_QRTR) += qrtr/ +obj-$(CONFIG_TSN) += tsn/ diff --git a/net/tsn/Makefile b/net/tsn/Makefile new file mode 100644 index 0000000..0d87687 --- /dev/null +++ b/net/tsn/Makefile @@ -0,0 +1,6 @@ +# +# Makefile for the Linux TSN subsystem +#

+obj-$(CONFIG_TSN) += tsn.o +tsn-objs :=tsn_core.o tsn_configfs.o tsn_net.o tsn_header.o diff --git a/net/tsn/tsn_configfs.c b/net/tsn/tsn_configfs.c new file mode 100644 index 0000000..f3d0986 --- /dev/null +++ b/net/tsn/tsn_configfs.c @@ -0,0 +1,623 @@ +/*

• • ConfigFS interface to TSN
• • Copyright (C) 2015- Henrik Austad haustad@cisco.com
• • This program is free software; you can redistribute it and/or modify
• • it under the terms of the GNU General Public License as published by
• • the Free Software Foundation; either version 2 of the License, or
• • (at your option) any later version.
• • 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/init.h> +#include <linux/module.h> +#include <linux/slab.h> +#include <linux/configfs.h> +#include <linux/netdevice.h> +#include <linux/rtmutex.h> +#include <linux/tsn.h> +#include "tsn_internal.h"

+static inline struct tsn_link *to_tsn_link(struct config_item *item) +{

• /* this line causes checkpatch to WARN. making checkpatch happy,

• * makes code messy..
  

• */
  

• return item ? container_of(to_config_group(item), struct tsn_link, group) : NULL;

+}

+static inline struct tsn_nic *to_tsn_nic(struct config_group *group) +{

• return group ? container_of(group, struct tsn_nic, group) : NULL;

+}

+/* -----------------------------------------------

• • Tier2 attributes
• • The content of the links userspace can see/modify

• • ---

+*/ +static ssize_t _tsn_max_payload_size_show(struct config_item *item,

• 			  char *page)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "%u\n", (u32)link->max_payload_size);

+}

+static ssize_t _tsn_max_payload_size_store(struct config_item *item,

• 			   const char *page, size_t count)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• u16 mpl_size = 0;
• int ret = 0;
• if (!link)

• return -EINVAL;
  

• if (tsn_link_is_on(link)) {

• pr_err("ERROR: Cannot change Payload size on on enabled link\n");
  

• return -EINVAL;
  

• }
• ret = kstrtou16(page, 0, &mpl_size);
• if (ret)

• return ret;
  

• /* 802.1BA-2011 6.4 payload must be <1500 octets (excluding

• * headers, tags etc) However, this is not directly mappable to
  

• * how some hw handles things, so to be conservative, we
  

• * restrict it down to [26..1485]
  

• *
  

• * This is also the _payload_ size, which does not include the
  

• * AVTPDU header. This is an upper limit to how much raw data
  

• * the shim can transport in each frame.
  

• */
  

• if (!tsnh_payload_size_valid(mpl_size, link->shim_header_size)) {

• pr_err("%s: payload (%u) should be [26..1480] octets.\n",
  

•        __func__, (u32)mpl_size);
  

• return -EINVAL;
  

• }
• link->max_payload_size = mpl_size;
• return count;

+}

+static ssize_t _tsn_shim_header_size_show(struct config_item *item,

• 			  char *page)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "%u\n", (u32)link->shim_header_size);

+}

+static ssize_t _tsn_shim_header_size_store(struct config_item *item,

• 			   const char *page, size_t count)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• u16 hdr_size = 0;
• int ret = 0;
• if (!link)

• return -EINVAL;
  

• if (tsn_link_is_on(link)) {

• pr_err("ERROR: Cannot change shim-header size on on enabled link\n");
  

• return -EINVAL;
  

• }
• ret = kstrtou16(page, 0, &hdr_size);
• if (ret)

• return ret;
  

• if (!tsnh_payload_size_valid(link->max_payload_size, hdr_size))

• return -EINVAL;
  

• link->shim_header_size = hdr_size;
• return count;

+}

+static ssize_t _tsn_stream_id_show(struct config_item *item, char *page) +{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "%llu\n", link->stream_id);

+}

+static ssize_t _tsn_stream_id_store(struct config_item *item,

• 		    const char *page, size_t count)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• u64 sid;
• int ret = 0;
• if (!link)

• return -EINVAL;
  

• if (tsn_link_is_on(link)) {

• pr_err("ERROR: Cannot change StreamID on on enabled link\n");
  

• return -EINVAL;
  

• }
• ret = kstrtou64(page, 0, &sid);
• if (ret)

• return ret;
  

• if (sid == link->stream_id)

• return count;
  

• if (tsn_find_by_stream_id(sid)) {

• pr_warn("Cannot set sid to %llu - exists\n", sid);
  

• return -EEXIST;
  

• }
• if (sid != link->stream_id)

• tsn_readd_link(link, sid);
  

• return count;

+}

+static ssize_t _tsn_buffer_size_show(struct config_item *item, char *page) +{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "%zu\n", link->buffer_size);

+}

+static ssize_t _tsn_buffer_size_store(struct config_item *item,

• 		      const char *page, size_t count)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• u32 tmp;
• int ret = 0;
• if (!link)

• return -EINVAL;
  

• if (tsn_link_is_on(link)) {

• pr_err("ERROR: Cannot change Buffer Size on on enabled link\n");
  

• return -EINVAL;
  

• }
• ret = kstrtou32(page, 0, &tmp);
• /* only allow buffers !0 and smaller than 8MB for now */
• if (!ret && tmp) {

• pr_info("%s: update buffer_size from %zu to %u\n",
  

• 	__func__, link->buffer_size, tmp);
  

• link->buffer_size = (size_t)tmp;
  

• return count;
  

• }
• return -EINVAL;

+}

+static ssize_t _tsn_class_show(struct config_item *item, char *page) +{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "%s\n", (link->class_a ? "A" : "B"));

+}

+static ssize_t _tsn_class_store(struct config_item *item,

• 		const char *page, size_t count)
  

+{

• char class[2] = { 0 };
• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• if (tsn_link_is_on(link)) {

• pr_err("ERROR: Cannot change Class-type on on enabled link\n");
  

• return -EINVAL;
  

• }
• if (strncpy(class, page, 1)) {

• if (strcmp(class, "a") == 0 || strcmp(class, "A") == 0)
  

• 	link->class_a = 1;
  

• else if (strcmp(class, "b") == 0 || strcmp(class, "B") == 0)
  

• 	link->class_a = 0;
  

• return count;
  

• }
• pr_err("%s: Could not copy new class into buffer\n", __func__);
• return -EINVAL;

+}

+static ssize_t _tsn_vlan_id_show(struct config_item *item, char *page) +{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "%u\n", link->vlan_id);

+}

+static ssize_t _tsn_vlan_id_store(struct config_item *item,

• 		  const char *page, size_t count)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• u16 vlan_id;
• int ret = 0;
• if (!link)

• return -EINVAL;
  

• if (tsn_link_is_on(link)) {

• pr_err("ERROR: Cannot change VLAN-ID on on enabled link\n");
  

• return -EINVAL;
  

• }
• ret = kstrtou16(page, 0, &vlan_id);
• if (ret)

• return ret;
  

• if (vlan_id > 0xfff)

• return -EINVAL;
  

• link->vlan_id = vlan_id & 0xfff;
• return count;

+}

+static ssize_t _tsn_pcp_a_show(struct config_item *item, char *page) +{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "0x%x\n", link->pcp_a);

+}

+static ssize_t _tsn_pcp_a_store(struct config_item *item,

• 		const char *page, size_t count)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• int ret = 0;
• u8 pcp;
• if (!link)

• return -EINVAL;
  

• if (tsn_link_is_on(link)) {

• pr_err("ERROR: Cannot change PCP-A on enabled link.\n");
  

• return -EINVAL;
  

• }
• ret = kstrtou8(page, 0, &pcp);
• if (ret)

• return ret;
  

• if (pcp > 0x7)

• return -EINVAL;
  

• link->pcp_a = pcp & 0x7;
• return count;

+}

+static ssize_t _tsn_pcp_b_show(struct config_item *item, char *page) +{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "0x%x\n", link->pcp_b);

+}

+static ssize_t _tsn_pcp_b_store(struct config_item *item,

• 		const char *page, size_t count)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• int ret = 0;
• u8 pcp;
• if (!link)

• return -EINVAL;
  

• if (tsn_link_is_on(link)) {

• pr_err("ERROR: Cannot change PCP-B on enabled link.\n");
  

• return -EINVAL;
  

• }
• ret = kstrtou8(page, 0, &pcp);
• if (ret)

• return ret;
  

• if (pcp > 0x7)

• return -EINVAL;
  

• link->pcp_b = pcp & 0x7;
• return count;

+}

+static ssize_t _tsn_end_station_show(struct config_item *item, char *page) +{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "%s\n",

•       (link->estype_talker ? "Talker" : "Listener"));
  

+}

+static ssize_t _tsn_end_station_store(struct config_item *item,

• 		      const char *page, size_t count)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• char estype[9] = {0};
• if (!link)

• return -EINVAL;
  

• if (tsn_link_is_on(link)) {

• pr_err("ERROR: Cannot change End-station type on enabled link.\n");
  

• return -EINVAL;
  

• }
• if (strncpy(estype, page, 8)) {

• if (strncmp(estype, "Talker", 6) == 0 ||
  

•     strncmp(estype, "talker", 6) == 0) {
  

• 	link->estype_talker = 1;
  

• 	return count;
  

• } else if (strncmp(estype, "Listener", 8) == 0 ||
  

• 	   strncmp(estype, "listener", 8) == 0) {
  

• 	link->estype_talker = 0;
  

• 	return count;
  

• }
  

• }
• return -EINVAL;

+}

+static ssize_t _tsn_enabled_show(struct config_item *item, char *page) +{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "%s\n", tsn_shim_get_active(link));

+}

+static ssize_t _tsn_enabled_store(struct config_item *item,

• 		  const char *page, size_t count)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• char driver_type[SHIM_NAME_SIZE] = { 0 };
• struct tsn_shim_ops *shim_ops;
• size_t len;
• int ret = 0;
• if (!link)

• return -EINVAL;
  

• strncpy(driver_type, page, SHIM_NAME_SIZE - 1);
• len = strlen(driver_type);
• while (len-- > 0) {

• if (driver_type[len] == '\n')
  

• 	driver_type[len] = 0x00;
  

• }
• if (tsn_link_is_on(link)) {

• if (strncmp(driver_type, "off", 3) == 0) {
  

• 	tsn_teardown_link(link);
  

• } else {
  

• 	pr_err("Unknown value (%s), ignoring\n", driver_type);
  

• 	return -EINVAL;
  

• }
  

• } else {

• shim_ops = tsn_shim_find_by_name(driver_type);
  

• if (!shim_ops) {
  

• 	pr_info("%s: could not enable desired shim, %s is not available\n",
  

• 		__func__, driver_type);
  

• 	return -EINVAL;
  

• }
  

• ret = tsn_prepare_link(link, shim_ops);
  

• if (ret != 0) {
  

• 	pr_err("%s: Trouble perparing link, somethign went wrong - %d\n",
  

• 	       __func__, ret);
  

• 	return ret;
  

• }
  

• }
• return count;

+}

+static ssize_t _tsn_remote_mac_show(struct config_item *item, char *page) +{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "%pM\n", link->remote_mac);

+}

+static ssize_t _tsn_remote_mac_store(struct config_item *item,

• 		     const char *page, size_t count)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• unsigned char mac[6] = {0};
• int ret = 0;
• if (!link)

• return -EINVAL;
  

• if (tsn_link_is_on(link)) {

• pr_err("ERROR: Cannot change Remote MAC on enabled link.\n");
  

• return -EINVAL;
  

• }
• ret = sscanf(page, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",

•      &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5]);
  

• if (ret > 0) {

• pr_info("Got MAC, copying to storage\n");
  

• memcpy(link->remote_mac, mac, 6);
  

• return count;
  

• }
• return -EINVAL;

+}

+static ssize_t _tsn_local_mac_show(struct config_item *item, char *page) +{

• struct tsn_link *link = to_tsn_link(item);
• if (!link)

• return -EINVAL;
  

• return sprintf(page, "%pMq\n", link->nic->dev->perm_addr);

+}

+CONFIGFS_ATTR(_tsn_, max_payload_size); +CONFIGFS_ATTR(_tsn_, shim_header_size); +CONFIGFS_ATTR(_tsn_, stream_id); +CONFIGFS_ATTR(_tsn_, buffer_size); +CONFIGFS_ATTR(_tsn_, class); +CONFIGFS_ATTR(_tsn_, vlan_id); +CONFIGFS_ATTR(_tsn_, pcp_a); +CONFIGFS_ATTR(_tsn_, pcp_b); +CONFIGFS_ATTR(_tsn_, end_station); +CONFIGFS_ATTR(_tsn_, enabled); +CONFIGFS_ATTR(_tsn_, remote_mac); +CONFIGFS_ATTR_RO(_tsn_, local_mac); +static struct configfs_attribute *tsn_tier2_attrs[] = {

• &_tsn_attr_max_payload_size,
• &_tsn_attr_shim_header_size,
• &_tsn_attr_stream_id,
• &_tsn_attr_buffer_size,
• &_tsn_attr_class,
• &_tsn_attr_vlan_id,
• &_tsn_attr_pcp_a,
• &_tsn_attr_pcp_b,
• &_tsn_attr_end_station,
• &_tsn_attr_enabled,
• &_tsn_attr_remote_mac,
• &_tsn_attr_local_mac,
• NULL,

+};

+static struct config_item_type group_tsn_tier2_type = {

• .ct_owner = THIS_MODULE,
• .ct_attrs = tsn_tier2_attrs,
• .ct_group_ops = NULL,

+};

+/* -----------------------------------------------

• • Tier1
• • The only interesting info at this level are the available links
• • belonging to this nic. This will be the subdirectories. Apart from
• • making/removing tier-2 folders, nothing else is required here.
• */

+static struct config_group *group_tsn_1_make_group(struct config_group *group,

• 				   const char *name)
  

+{

• struct tsn_nic *nic = to_tsn_nic(group);
• struct tsn_link *link = tsn_create_and_add_link(nic);
• if (!nic || !link)

• return ERR_PTR(-ENOMEM);
  

• config_group_init_type_name(&link->group, name, &group_tsn_tier2_type);
• return &link->group;

+}

+static void group_tsn_1_drop_group(struct config_group *group,

• 		   struct config_item *item)
  

+{

• struct tsn_link *link = to_tsn_link(item);
• struct tsn_nic *nic = to_tsn_nic(group);
• if (link) {

• tsn_teardown_link(link);
  

• tsn_remove_link(link);
  

• }
• pr_info("Dropping %s from NIC: %s\n", item->ci_name, nic->name);

+}

+static struct configfs_attribute *tsn_tier1_attrs[] = {

• NULL,

+};

+static struct configfs_group_operations group_tsn_1_group_ops = {

• .make_group = group_tsn_1_make_group,
• .drop_item = group_tsn_1_drop_group,

+};

+static struct config_item_type group_tsn_tier1_type = {

• .ct_group_ops = &group_tsn_1_group_ops,
• .ct_attrs = tsn_tier1_attrs,
• .ct_owner = THIS_MODULE,

+};

+/* -----------------------------------------------

• • Tier0
• • Top level. This will expose all the TSN-capable NICs as well as
• • currently active StreamIDs and registered shims. 'Global' info goes
• • here.
• */

+static ssize_t _tsn_used_sids_show(struct config_item *item, char *page) +{

• return tsn_get_stream_ids(page, PAGE_SIZE);

+}

+static ssize_t _tsn_available_shims_show(struct config_item *item, char *page) +{

• return tsn_shim_export_probe_triggers(page);

+}

+static struct configfs_attribute tsn_used_sids = {

• .ca_owner = THIS_MODULE,
• .ca_name = "stream_ids",
• .ca_mode = S_IRUGO,
• .show = _tsn_used_sids_show,

+};

+static struct configfs_attribute available_shims = {

• .ca_owner = THIS_MODULE,
• .ca_name = "available_shims",
• .ca_mode = S_IRUGO,
• .show = _tsn_available_shims_show,

+};

+static struct configfs_attribute *group_tsn_attrs[] = {

• &tsn_used_sids,
• &available_shims,
• NULL,

+};

+static struct config_item_type group_tsn_tier0_type = {

• .ct_group_ops = NULL,
• .ct_attrs = group_tsn_attrs,
• .ct_owner = THIS_MODULE,

+};

+int tsn_configfs_init(struct tsn_list *tlist) +{

• int ret = 0;
• struct tsn_nic *next;
• struct configfs_subsystem *subsys;
• if (!tlist || !tlist->num_avail)

• return -EINVAL;
  

• /* Tier-0 */
• subsys = &tlist->tsn_subsys;
• strncpy(subsys->su_group.cg_item.ci_namebuf, "tsn",

• CONFIGFS_ITEM_NAME_LEN);
  

• subsys->su_group.cg_item.ci_type = &group_tsn_tier0_type;
• config_group_init(&subsys->su_group);
• mutex_init(&subsys->su_mutex);
• /* Tier-1

• * (tsn-capable NICs), automatic subgroups
  

• */
  

• list_for_each_entry(next, &tlist->head, list) {

• config_group_init_type_name(&next->group, next->name,
  

• 			    &group_tsn_tier1_type);
  

• configfs_add_default_group(&next->group, &subsys->su_group);
  

• }
• /* This is the final step, once done, system is live, make sure

• * init has completed properly
  

• */
  

• ret = configfs_register_subsystem(subsys);
• if (ret) {

• pr_err("Trouble registering TSN ConfigFS subsystem\n");
  

• return ret;
  

• }
• pr_warn("configfs_init_module() OK\n");
• return 0;

+}

+void tsn_configfs_exit(struct tsn_list *tlist) +{

• if (!tlist)

• return;
  

• configfs_unregister_subsystem(&tlist->tsn_subsys);
• pr_warn("configfs_exit_module()\n");

+} diff --git a/net/tsn/tsn_core.c b/net/tsn/tsn_core.c new file mode 100644 index 0000000..51f1d13 --- /dev/null +++ b/net/tsn/tsn_core.c @@ -0,0 +1,975 @@ +/*

• • TSN Core main part of TSN driver
• • Copyright (C) 2015- Henrik Austad haustad@cisco.com
• • This program is free software; you can redistribute it and/or modify
• • it under the terms of the GNU General Public License as published by
• • the Free Software Foundation; either version 2 of the License, or
• • (at your option) any later version.
• • 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/pci.h> +#include <linux/slab.h> +#include <linux/init.h> +#include <linux/module.h> +#include <linux/random.h> +#include <linux/rtmutex.h> +#include <linux/hashtable.h> +#include <linux/netdevice.h> +#include <linux/net.h> +#include <linux/dma-mapping.h> +#include <net/sock.h> +#include <net/net_namespace.h> +#include <linux/hrtimer.h> +#include <linux/configfs.h>

+#define CREATE_TRACE_POINTS +#include <trace/events/tsn.h> +#include "tsn_internal.h"

+static struct tsn_list tlist; +static int in_debug; +static int on_cpu = -1;

+#define TLINK_HASH_BITS 8 +DEFINE_HASHTABLE(tlinks, TLINK_HASH_BITS);

+static LIST_HEAD(tsn_shim_ops);

+/* Called with link->lock held */ +static inline size_t _get_low_water(struct tsn_link *link) +{

• /* use max_payload_size and give a rough estimate of how many

• * bytes that would be for low_water_ms
  

• */
  

• int low_water_ms = 20;
• int numframes = low_water_ms * 8;
• if (link->class_a)

• numframes *= 2;
  

• return link->max_payload_size * numframes;

+}

+/* Called with link->lock held */ +static inline size_t _get_high_water(struct tsn_link *link) +{

• size_t low_water = _get_low_water(link);
• return max(link->used_buffer_size - low_water, low_water);

+}

+/**

• • _tsn_set_buffer - register a memory region to use as the buffer
• • This is used when we are operating in !external_buffer mode.
• • TSN expects a ring-buffer and will update pointers to keep track of
• • where we are. When the buffer is refilled, head and tail will be
• • updated accordingly.
• • @param link the link that should hold the buffer
• • @param buffer the new buffer
• • @param bufsize size of new buffer.
• • @returns 0 on success, negative on error
• • Must be called with tsn_lock() held.
• */

+static int _tsn_set_buffer(struct tsn_link *link, void *buffer, size_t bufsize) +{

• if (link->buffer) {

• pr_err("%s: Cannot add buffer, buffer already registred\n",
  

•        __func__);
  

• return -EINVAL;
  

• }
• trace_tsn_set_buffer(link, bufsize);
• link->buffer = buffer;
• link->head = link->buffer;
• link->tail = link->buffer;
• link->end = link->buffer + bufsize;
• link->buffer_size = bufsize;
• link->used_buffer_size = bufsize;
• return 0;

+}

+/**

• • _tsn_free_buffer - remove internal buffers
• • This is the buffer where we store data before shipping it to TSN, or
• • where incoming data is staged.
• • @param link - the link that holds the buffer
• • Must be called with tsn_lock() held.
• */

+static void _tsn_free_buffer(struct tsn_link *link) +{

• if (!link)

• return;
  

• trace_tsn_free_buffer(link);
• kfree(link->buffer);
• link->buffer = NULL;
• link->head = NULL;
• link->tail = NULL;
• link->end = NULL;

+}

+int tsn_set_buffer_size(struct tsn_link *link, size_t bsize) +{

• if (!link)

• return -EINVAL;
  

• if (bsize > link->buffer_size) {

• pr_err("%s: requested buffer (%zd) larger than allocated memory (%zd)\n",
  

•        __func__, bsize, link->buffer_size);
  

• return -ENOMEM;
  

• }
• tsn_lock(link);
• link->used_buffer_size = bsize;
• link->tail = link->buffer;
• link->head = link->buffer;
• link->end = link->buffer + link->used_buffer_size;
• link->low_water_mark = _get_low_water(link);
• link->high_water_mark = _get_high_water(link);
• tsn_unlock(link);
• pr_info("Set buffer_size, size: %zd, lowwater: %zd, highwater: %zd\n",

• link->used_buffer_size, link->low_water_mark,
  

• link->high_water_mark);
  

• return 0;

+} +EXPORT_SYMBOL(tsn_set_buffer_size);

+int tsn_clear_buffer_size(struct tsn_link *link) +{

• if (!link)

• return -EINVAL;
  

• tsn_lock(link);
• link->tail = link->buffer;
• link->head = link->buffer;
• link->end = link->buffer + link->buffer_size;
• memset(link->buffer, 0, link->used_buffer_size);
• link->used_buffer_size = link->buffer_size;
• link->low_water_mark = _get_low_water(link);
• link->high_water_mark = _get_high_water(link);
• tsn_unlock(link);
• return 0;

+} +EXPORT_SYMBOL(tsn_clear_buffer_size);

+void *tsn_set_external_buffer(struct tsn_link *link, void *buffer,

• 	      size_t buffer_size)
  

+{

• void *old_buffer;
• if (!link)

• return NULL;
  

• if (buffer_size < link->max_payload_size)

• pr_warn("%s: buffer_size (%zu) < max_payload_size (%u)\n",
  

• 	__func__, buffer_size, link->max_payload_size);
  

• tsn_lock(link);
• if (!link->external_buffer && link->buffer)

• _tsn_free_buffer(link);
  

• old_buffer = link->buffer;
• link->external_buffer = 1;
• link->buffer_size = buffer_size;
• link->used_buffer_size = buffer_size;
• link->buffer = buffer;
• link->head = link->buffer;
• link->tail = link->buffer;
• link->end = link->buffer + link->used_buffer_size;
• tsn_unlock(link);
• return old_buffer;

+} +EXPORT_SYMBOL(tsn_set_external_buffer);

+/* Caller must hold link->lock!

• • Write data *into* buffer, either from net or from shim due to a
• • closing underflow event.
• */

+static void __tsn_buffer_write(struct tsn_link *link, void *src, size_t bytes) +{

• int rem = 0;
• /* No Need To Wrap, if overflow we will overwrite without

• * warning.
  

• */
  

• trace_tsn_buffer_write(link, bytes);
• if (link->head + bytes < link->end) {

• memcpy(link->head, src, bytes);
  

• link->head += bytes;
  

• } else {

• rem = link->end - link->head;
  

• memcpy(link->head, src, rem);
  

• memcpy(link->buffer, (src + rem), bytes - rem);
  

• link->head = link->buffer + (bytes - rem);
  

• }

+}

+int tsn_buffer_write(struct tsn_link *link, void *src, size_t bytes) +{

• if (!link)

• return -EINVAL;
  

• /* We should not do anything if link has gone inactive */
• if (!tsn_link_is_on(link))

• return 0;
  

• /* Copied a batch of data and if link is disabled, it is now

• * safe to enable it. Otherwise we will continue to send
  

• * null-frames to remote.
  

• */
  

• if (!tsn_lb(link))

• tsn_lb_enable(link);
  

• __tsn_buffer_write(link, src, bytes);
• return bytes;

+} +EXPORT_SYMBOL(tsn_buffer_write);

+/**

• • tsn_buffer_write_net - take data from a skbuff and write it into buffer
• • When we receive a frame, we grab data from the skbuff and add it to
• • link->buffer.
• • Note that this routine does NOT CARE about channels, samplesize etc,
• • it is a _pure_ copy that handles ringbuffer wraps etc.
• • This function have side-effects as it will update internal tsn_link
• • values and trigger refill() should the buffer run low.
• • NOTE: called from tsn_rx_handler() -> _tsnh_handle_du(), with

• • tsn_lock held.
    

• • @param link current link that holds the buffer
• • @param buffer the buffer to copy from
• • @param bytes number of bytes
• • @returns Bytes copied into link->buffer, negative value upon error.
• */

+int tsn_buffer_write_net(struct tsn_link *link, void *src, size_t bytes) +{

• size_t used;
• if (!link)

• return -EINVAL;
  

• /* Driver has not been enabled yet, i.e. it is in state 'off' and we

• * have no way of knowing the state of the buffers.
  

• * Silently drop the data, pretend write went ok
  

• */
  

• trace_tsn_buffer_write_net(link, bytes);
• if (!tsn_lb(link))

• return bytes;
  

• __tsn_buffer_write(link, src, bytes);
• /* If we stored more data than high_water, we need to drain

• *
  

• * In ALSA, this will trigger a snd_pcm_period_elapsed() for the
  

• * substream connected to this particular link.
  

• */
  

• used = _tsn_buffer_used(link);
• if (used > link->high_water_mark) {

• trace_tsn_buffer_drain(link, used);
  

• link->ops->buffer_drain(link);
  

• }
• return bytes;

+}

+/* caller must hold link->lock!

• • Read data *from* buffer, either to net or to shim due to a
• • closing overflow event.
• • Function will *not* care if you read past head and into unchartered
• • territory, caller must ascertain validity of bytes.
• */

+static void __tsn_buffer_read(struct tsn_link *link, void *dst, size_t bytes) +{

• int rem = 0;
• trace_tsn_buffer_read(link, bytes);
• if ((link->tail + bytes) < link->end) {

• memcpy(dst, link->tail, bytes);
  

• link->tail += bytes;
  

• } else {

• rem = link->end - link->tail;
  

• memcpy(dst, link->tail, rem);
  

• memcpy(dst + rem, link->buffer, bytes - rem);
  

• link->tail = link->buffer + bytes - rem;
  

• }

+}

+/**

• • tsn_buffer_read_net - read data from link->buffer and give to network layer
• • When we send a frame, we grab data from the buffer and add it to the
• • sk_buff->data, this is primarily done by the Tx-subsystem in tsn_net
• • and is typically done in small chunks
• • @param link current link that holds the buffer
• • @param buffer the buffer to copy into, must be at least of size bytes
• • @param bytes number of bytes.
• • Note that this routine does NOT CARE about channels, samplesize etc,
• • it is a _pure_ copy that handles ringbuffer wraps etc.
• • This function have side-effects as it will update internal tsn_link
• • values and trigger refill() should the buffer run low.
• • NOTE: expects to be called with locks held
• • @return Bytes copied into link->buffer, negative value upon error.
• */

+int tsn_buffer_read_net(struct tsn_link *link, void *buffer, size_t bytes) +{

• size_t used;
• if (!link)

• return -EINVAL;
  

• /* link is currently inactive, e.g. we send frames, but without

• * content
  

• *
  

• * This can be done before we ship data, or if we are muted
  

• * (without expressively stating that over 1722.1
  

• *
  

• * We do not need to grab any locks here as we won't touch the
  

• * link
  

• */
  

• if (!tsn_lb(link)) {

• memset(buffer, 0, bytes);
  

• goto out;
  

• }
• /* sanity check of bytes to read

• * FIXME
  

• */
  

• __tsn_buffer_read(link, buffer, bytes);
• /* Trigger refill from client app */
• used = _tsn_buffer_used(link);
• if (used < link->low_water_mark) {

• trace_tsn_refill(link, used);
  

• link->ops->buffer_refill(link);
  

• }

+out:

• return bytes;

+}

+int tsn_buffer_read(struct tsn_link *link, void *buffer, size_t bytes) +{

• if (!link)

• return -EINVAL;
  

• /* We should not do anything if link has gone inactive */
• if (!tsn_link_is_on(link))

• return 0;
  

• tsn_lock(link);
• __tsn_buffer_read(link, buffer, bytes);
• tsn_unlock(link);
• return bytes;

+} +EXPORT_SYMBOL(tsn_buffer_read);

+static int _tsn_send_batch(struct tsn_link *link) +{

• int ret = 0;
• int num_frames = (link->class_a ? 8 : 4);
• u64 ts_base_ns = ktime_to_ns(ktime_get()) + (link->class_a ? 2000000 : 50000000);
• u64 ts_delta_ns = (link->class_a ? 125000 : 250000);
• trace_tsn_send_batch(link, num_frames, ts_base_ns, ts_delta_ns);
• ret = tsn_net_send_set(link, num_frames, ts_base_ns, ts_delta_ns);
• if (ret < 0)

• pr_err("%s: could not send frame - %d\n", __func__, ret);
  

• return ret;

+}

+static int _tsn_hrtimer_callback(struct tsn_link *link) +{

• int ret = _tsn_send_batch(link);
• if (ret) {

• pr_err("%s: Error sending frames (%d), disabling link.\n",
  

•        __func__, ret);
  

• tsn_teardown_link(link);
  

• return 0;
  

• }
• return 0;

+}

+static enum hrtimer_restart tsn_hrtimer_callback(struct hrtimer *hrt) +{

• struct tsn_list *list = container_of(hrt, struct tsn_list, tsn_timer);
• struct tsn_link *link;
• struct hlist_node *tmp;
• int bkt = 0;
• if (!tsn_core_running(list))

• return HRTIMER_NORESTART;
  

• hrtimer_forward_now(hrt, ns_to_ktime(list->period_ns));
• hash_for_each_safe(tlinks, bkt, tmp, link, node) {

• if (tsn_link_is_on(link) && link->estype_talker)
  

• 	_tsn_hrtimer_callback(link);
  

• }
• return HRTIMER_RESTART;

+}

+static long tsn_hrtimer_init(void *arg) +{

• /* Run every 1ms, _tsn_send_batch will figure out how many

• * frames to send for active frames
  

• */
  

• struct tsn_list *list = (struct tsn_list *)arg;
• hrtimer_init(&list->tsn_timer, CLOCK_MONOTONIC,

•      HRTIMER_MODE_REL | HRTIMER_MODE_PINNED);
  

• list->tsn_timer.function = tsn_hrtimer_callback;
• hrtimer_cancel(&list->tsn_timer);
• atomic_set(&list->running, 1);
• hrtimer_start(&list->tsn_timer, ns_to_ktime(list->period_ns),

•       HRTIMER_MODE_REL);
  

• return 0;

+}

+static void tsn_hrtimer_exit(struct tsn_list *list) +{

• atomic_set(&list->running, 0);
• hrtimer_cancel(&list->tsn_timer);

+}

+/**

• • tsn_prepare_link - prepare link for role as Talker/Receiver
• • Iow; this will start shipping data through the network-layer.
• • @link: the actual link
• • Current status: each link will get a periodic hrtimer that interrupts
• • and ships data every 1ms. This will change once we have proper driver
• • for hw (i.e. i210 driver).
• */

+int tsn_prepare_link(struct tsn_link *link, struct tsn_shim_ops *shim_ops) +{

• int ret = 0;
• void *buffer;
• u16 framesize;
• struct net_device *netdev;
• /* TODO: use separate buckets (lists/rbtrees/whatever) for

• * class_a and class_b talker streams. hrtimer-callback should
  

• * not iterate over all.
  

• */
  

• if (!link || !shim_ops || !shim_ops->probe)

• return -EINVAL;
  

• pr_info("TSN: allocating buffer, %zd bytes\n", link->buffer_size);
• tsn_lock(link);
• /* configure will calculate idle_slope based on framesize

• * (header + payload)
  

• */
  

• netdev = link->nic->dev;
• if (netdev->netdev_ops->ndo_tsn_link_configure) {

• framesize  = link->max_payload_size +
  

• 	     link->shim_header_size + tsnh_len_all();
  

• ret = netdev->netdev_ops->ndo_tsn_link_configure(netdev, link->class_a,
  

• 						 framesize, link->vlan_id & 0xfff);
  

• if (ret < 0)
  

• 	pr_err("Could not configure link - %d\n", ret);
  

• }
• link->ops = shim_ops;
• tsn_unlock(link);
• ret = link->ops->probe(link);
• if (ret != 0) {

• pr_err("%s: Could not probe shim (%d), cannot create link\n",
  

•        __func__, ret);
  

• link->ops = NULL;
  

• goto out;
  

• }
• tsn_lock(link);
• if (!link->external_buffer) {

• buffer = kmalloc(link->buffer_size, GFP_KERNEL);
  

• if (!buffer) {
  

• 	pr_err("%s: Could not allocate memory (%zu) for buffer\n",
  

• 	       __func__, link->buffer_size);
  

• 	link->ops = NULL;
  

• 	ret = -ENOMEM;
  

• 	goto unlock_out;
  

• }
  

• ret = _tsn_set_buffer(link, buffer, link->buffer_size);
  

• if (ret != 0) {
  

• 	pr_err("%s: Could not set buffer for TSN, got %d\n",
  

• 	       __func__, ret);
  

• 	goto unlock_out;
  

• }
  

• } else {

• /* FIXME: not handled */
  

• pr_info("TSN does not currently handle externally hosted buffers. This is on the TODO-list\n");
  

• ret = -EINVAL;
  

• goto unlock_out;
  

• }
• tsn_link_on(link);

+unlock_out:

• tsn_unlock(link);

+out:

• pr_info("%s: ret=%d\n", __func__, ret);
• return ret;

+}

+int tsn_teardown_link(struct tsn_link *link) +{

• if (!link)

• return -EINVAL;
  

• tsn_lock(link);
• tsn_lb_disable(link);
• tsn_link_off(link);
• tsn_unlock(link);
• /* Need to call media_close() without (spin-)locks held.

• */
  

• if (link->ops)

• link->ops->media_close(link);
  

• tsn_lock(link);
• link->ops = NULL;
• _tsn_free_buffer(link);
• tsn_unlock(link);
• pr_info("%s: disabling all parts of link\n", __func__);
• return 0;

+}

+int tsn_shim_register_ops(struct tsn_shim_ops *shim_ops) +{

• if (!shim_ops)

• return -EINVAL;
  

• if (!shim_ops->buffer_refill || !shim_ops->buffer_drain ||

•    !shim_ops->media_close || !shim_ops->copy_size ||
  

•    !shim_ops->validate_header || !shim_ops->assemble_header ||
  

•    !shim_ops->get_payload_data)
  

• return -EINVAL;
  

• INIT_LIST_HEAD(&shim_ops->head);
• list_add_tail(&shim_ops->head, &tsn_shim_ops);
• return 0;

+} +EXPORT_SYMBOL(tsn_shim_register_ops);

+void tsn_shim_deregister_ops(struct tsn_shim_ops *shim_ops) +{

• struct tsn_link *link;
• struct hlist_node *tmp;
• int bkt;
• hash_for_each_safe(tlinks, bkt, tmp, link, node) {

• if (!link)
  

• 	continue;
  

• if (link->ops == shim_ops)
  

• 	tsn_teardown_link(link);
  

• }
• list_del(&shim_ops->head);

+} +EXPORT_SYMBOL(tsn_shim_deregister_ops);

+char *tsn_shim_get_active(struct tsn_link *link) +{

• if (!link || !link->ops)

• return "off";
  

• return link->ops->shim_name;

+}

+struct tsn_shim_ops *tsn_shim_find_by_name(const char *name) +{

• struct tsn_shim_ops *ops;
• if (!name || list_empty(&tsn_shim_ops))

• return NULL;
  

• list_for_each_entry(ops, &tsn_shim_ops, head) {

• if (strcmp(name, ops->shim_name) == 0)
  

• 	return ops;
  

• }
• return NULL;

+}

+ssize_t tsn_shim_export_probe_triggers(char *page) +{

• struct tsn_shim_ops *ops;
• ssize_t res = 0;
• if (!page || list_empty(&tsn_shim_ops))

• return 0;
  

• list_for_each_entry(ops, &tsn_shim_ops, head) {

• res += snprintf((page + res), PAGE_SIZE - res, "%s\n",
  

• 		 ops->shim_name);
  

• }
• return res;

+}

+struct tsn_link *tsn_create_and_add_link(struct tsn_nic *nic) +{

• u64 sid = 0;
• struct tsn_link *link = kzalloc(sizeof(*link), GFP_KERNEL);
• if (!link)

• return NULL;
  

• if (!nic) {

• kfree(link);
  

• return NULL;
  

• }
• spin_lock_init(&link->lock);
• tsn_lock(link);
• tsn_link_off(link);
• tsn_lb_disable(link);
• do {

• sid = prandom_u32();
  

• sid |= prandom_u32() << 31;
  

• } while (tsn_find_by_stream_id(sid));
• link->stream_id = sid;
• /* There's a slim chance that we actually hit on the first frame

• * of data, but if we do, remote seqnr is most likely 0. If this
  

• * is not up to par,, fix in rx_handler
  

• */
  

• link->last_seqnr = 0xff;
• /* class B audio 48kHz sampling, S16LE, 2ch and IEC61883-6 CIP

• * header
  

• */
  

• link->max_payload_size = 48;
• link->shim_header_size = 8;
• /* Default VLAN ID is SR_PVID (2) unless otherwise supplied from

• * MSRP, PCP is default 3 for class A, 2 for Class B (See IEEE
  

• * 802.1Q-2011, table 6-6)
  

• */
  

• link->vlan_id = 0x2;
• link->pcp_a = 3;
• link->pcp_b = 2;
• link->class_a = 0;
• link->buffer_size = 16536;
• /* default: talker since listener isn't implemented yet. */
• link->estype_talker = 1;
• link->nic = nic;
• tsn_unlock(link);
• /* Add the newly created link to the hashmap of all active links.

• *
  

• * test if sid is present in hashmap already (barf on that)
  

• */
  

• mutex_lock(&tlist.lock);
• hash_add(tlinks, &link->node, link->stream_id);
• mutex_unlock(&tlist.lock);
• pr_info("%s: added link with stream_id: %llu\n",

• __func__, link->stream_id);
  

• return link;

+}

+ssize_t tsn_get_stream_ids(char *page, ssize_t len) +{

• struct tsn_link *link;
• struct hlist_node *tmp;
• char *buffer = page;
• int bkt;
• if (!page)

• return 0;
  

• if (hash_empty(tlinks))

• return sprintf(buffer, "no links registered\n");
  

• hash_for_each_safe(tlinks, bkt, tmp, link, node)

• buffer += sprintf(buffer, "%llu\n", link->stream_id);
  

• return (buffer - page);

+}

+struct tsn_link *tsn_find_by_stream_id(u64 sid) +{

• struct tsn_link *link;
• if (hash_empty(tlinks))

• return 0;
  

• hash_for_each_possible(tlinks, link, node, sid) {

• if (link->stream_id == sid)
  

• 	return link;
  

• }
• return NULL;

+}

+void tsn_remove_link(struct tsn_link *link) +{

• if (!link)

• return;
  

• tsn_net_close(link);
• mutex_lock(&tlist.lock);
• hash_del(&link->node);
• if (link->ops) {

• link->ops->media_close(link);
  

• link->ops = NULL;
  

• }
• mutex_unlock(&tlist.lock);

+}

+void tsn_readd_link(struct tsn_link *link, u64 newkey) +{

• if (!link)

• return;
  

• tsn_lock(link);
• if (hash_hashed(&link->node)) {

• pr_info("%s: updating link with stream_id %llu -> %llu\n",
  

• 	__func__, link->stream_id, newkey);
  

• tsn_remove_link(link);
  

• }
• link->stream_id = newkey;
• tsn_unlock(link);
• hash_add(tlinks, &link->node, link->stream_id);

+}

+static int _tsn_capable_nic(struct net_device *netdev, struct tsn_nic *nic) +{

• if (!nic || !netdev || !netdev->netdev_ops ||

•    !netdev->netdev_ops->ndo_tsn_capable)
  

• return -EINVAL;
  

• if (netdev->netdev_ops->ndo_tsn_capable(netdev) > 0)

• nic->capable = 1;
  

• return 0;

+}

+/* Identify all TSN-capable NICs in the system

• */

+static int tsn_nic_probe(void) +{

• struct net *net;
• struct net_device *netdev;
• struct tsn_nic *nic;
• net = &init_net;
• rcu_read_lock();
• for_each_netdev_rcu(net, netdev) {

• pr_info("Found %s, alias %s on irq %d\n",
  

• 	netdev->name,
  

• 	netdev->ifalias,
  

• 	netdev->irq);
  

• pr_info("MAC: %pM", netdev->dev_addr);
  

• if (netdev->tx_queue_len)
  

• 	pr_info("Tx queue length: %lu\n", netdev->tx_queue_len);
  

• nic = kzalloc(sizeof(*nic), GFP_KERNEL);
  

• if (!nic) {
  

• 	pr_err("Could not allocate memory for tsn_nic!\n");
  

• 	return -ENOMEM;
  

• }
  

• nic->dev = netdev;
  

• nic->txq = netdev->num_tx_queues;
  

• nic->name = netdev->name;
  

• nic->tsn_list = &tlist;
  

• nic->dma_size = 1048576;
  

• _tsn_capable_nic(netdev, nic);
  

• /* if not capable and we are not in debug-mode, drop nic
  

•  * and continue
  

•  */
  

• if (!nic->capable && !in_debug) {
  

• 	pr_info("Invalid capabilities for NIC (%s), dropping from TSN list\n",
  

• 		netdev->name);
  

• 	kfree(nic);
  

• 	continue;
  

• }
  

• INIT_LIST_HEAD(&nic->list);
  

• mutex_lock(&tlist.lock);
  

• list_add_tail(&nic->list, &tlist.head);
  

• tlist.num_avail++;
  

• mutex_unlock(&tlist.lock);
  

• }
• rcu_read_unlock();
• return 0;

+}

+static void tsn_free_nic_list(struct tsn_list *list) +{

• struct tsn_nic *tmp, *next;
• mutex_lock(&list->lock);
• list_for_each_entry_safe(tmp, next, &list->head, list) {

• pr_info("Dropping %s from list\n", tmp->dev->name);
  

• list_del(&tmp->list);
  

• tmp->dev = NULL;
  

• kfree(tmp);
  

• }
• mutex_unlock(&list->lock);

+}

+/* all active links are stored in hashmap 'tlinks'

• */

+static void tsn_remove_all_links(void) +{

• int bkt;
• struct tsn_link *link;
• struct hlist_node *tmp;
• hash_for_each_safe(tlinks, bkt, tmp, link, node) {

• pr_info("%s removing a link\n", __func__);
  

• if (!tsn_teardown_link(link))
  

• 	tsn_remove_link(link);
  

• }
• pr_info("%s: all links have been removed\n", __func__);

+}

+static int __init tsn_init_module(void) +{

• int ret = 0;
• INIT_LIST_HEAD(&tlist.head);
• mutex_init(&tlist.lock);
• atomic_set(&tlist.running, 0);
• tlist.period_ns = 1000000;
• /* Find all NICs, attach a rx-handler for sniffing out TSN

• * traffic on *all* of them.
  

• */
  

• tlist.num_avail = 0;
• ret = tsn_nic_probe();
• if (ret < 0) {

• pr_err("%s: somethign went awry whilst probing for NICs, aborting\n",
  

•        __func__);
  

• goto out;
  

• }
• if (!tlist.num_avail) {

• pr_err("%s: No capable NIC found. Perhaps load with in_debug=1 ?\n",
  

•        __func__);
  

• ret = -EINVAL;
  

• goto out;
  

• }
• /* register Rx-callbacks for all (valid) NICs */
• ret = tsn_net_add_rx(&tlist);
• if (ret < 0) {

• pr_err("%s: Could add Rx-handler, aborting\n", __func__);
  

• goto error_rx_out;
  

• }
• /* init DMA regions etc */
• ret = tsn_net_prepare_tx(&tlist);
• if (ret < 0) {

• pr_err("%s: could not prepare Tx, aborting\n", __func__);
  

• goto error_tx_out;
  

• }
• /* init hashtable */
• hash_init(tlinks);
• /* init configfs */
• ret = tsn_configfs_init(&tlist);
• if (ret < 0) {

• pr_err("%s: Could not initialize configfs properly (%d), aborting\n",
  

•        __func__, ret);
  

• goto error_cfs_out;
  

• }
• /* Test to see if on_cpu is available */
• if (on_cpu >= 0) {

• pr_info("%s: pinning timer on CPU %d\n", __func__, on_cpu);
  

• ret = work_on_cpu(on_cpu, tsn_hrtimer_init, &tlist);
  

• if (ret != 0) {
  

• 	pr_err("%s: could not init hrtimer properly on CPU %d, aborting\n",
  

• 	       __func__, on_cpu);
  

• 	goto error_hrt_out;
  

• }
  

• } else {

• ret = tsn_hrtimer_init(&tlist);
  

• if (ret < 0) {
  

• 	pr_err("%s: could not init hrtimer properly, aborting\n",
  

• 	       __func__);
  

• 	goto error_hrt_out;
  

• }
  

• }
• pr_info("TSN subsystem init OK\n");
• return 0;

+error_hrt_out:

• tsn_remove_all_links();
• tsn_configfs_exit(&tlist);

+error_cfs_out:

• tsn_net_disable_tx(&tlist);

+error_tx_out:

• tsn_net_remove_rx(&tlist);

+error_rx_out:

• tsn_free_nic_list(&tlist);

+out:

• return ret;

+}

+static void __exit tsn_exit_module(void) +{

• pr_warn("removing module TSN\n");
• tsn_hrtimer_exit(&tlist);
• tsn_remove_all_links();
• tsn_configfs_exit(&tlist);
• /* Unregister Rx-handlers if set */
• tsn_net_remove_rx(&tlist);
• tsn_net_disable_tx(&tlist);
• tsn_free_nic_list(&tlist);
• pr_warn("TSN exit\n");

+} +module_param(in_debug, int, S_IRUGO); +module_param(on_cpu, int, S_IRUGO); +module_init(tsn_init_module); +module_exit(tsn_exit_module); +MODULE_AUTHOR("Henrik Austad"); +MODULE_LICENSE("GPL"); diff --git a/net/tsn/tsn_header.c b/net/tsn/tsn_header.c new file mode 100644 index 0000000..a0d31c5 --- /dev/null +++ b/net/tsn/tsn_header.c @@ -0,0 +1,203 @@ +/*

• • Network header handling for TSN
• • Copyright (C) 2015- Henrik Austad haustad@cisco.com
• • This program is free software; you can redistribute it and/or modify
• • it under the terms of the GNU General Public License as published by
• • the Free Software Foundation; either version 2 of the License, or
• • (at your option) any later version.
• • 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/tsn.h> +#include <trace/events/tsn.h>

+#include "tsn_internal.h"

+#define AVTP_GPTP_TIMEMASK 0xFFFFFFFF

+static u32 tsnh_avtp_timestamp(u64 ptime_ns) +{

• /* See 1722-2011, 5.4.8

• *
  

• * (AS_sec * 1e9 + AS_ns) % 2^32
  

• *
  

• * Just use ktime_get_ns() and grab lower 32 bits of it.
  

• */
  

• /* u64 ns = ktime_to_ns(ktime_get()); */
• u32 gptp_ts = ptime_ns & AVTP_GPTP_TIMEMASK;
• return gptp_ts;

+}

+int tsnh_ch_init(struct avtp_ch *header) +{

• if (!header)

• return -EINVAL;
  

• header = memset(header, 0, sizeof(*header));
• /* This should be changed when setting control / data

• * content. Set to experimental to allow for strange content
  

• * should callee not do job properly
  

• */
  

• header->subtype = AVTP_EXPERIMENTAL;
• header->version = 0;
• return 0;

+}

+int _tsnh_validate_du_header(struct tsn_link *link, struct avtp_ch *ch,

• 	     struct sk_buff *skb)
  

+{

• struct avtpdu_header *header = (struct avtpdu_header *)ch;
• struct sockaddr_ll *sll;
• u16 bytes;
• u8 seqnr;
• if (ch->cd)

• return -EINVAL;
  

• /* As a minimum, we should match the sender's MAC to the

• * expected MAC before we pass the frame along.
  

• *
  

• * This does not give much in the way of security (a malicious
  

• * user could probably fake this), but it should remove most
  

• * accidents.
  

• */
  

• sll = (struct sockaddr_ll *)&skb->cb;
• sll->sll_halen = dev_parse_header(skb, sll->sll_addr);
• if (sll->sll_halen != 6) {

• trace_printk("%s: received MAC address length mismatch. Expected 6 bytes, got %d\n",
  

• 	     __func__, sll->sll_halen);
  

• return -EPROTO;
  

• }
• if (memcmp(link->remote_mac, &sll->sll_addr, 6)) {

• trace_printk("%s: received MAC-address mismatch (expected %pM, got %pM), dropping frame\n",
  

• 	     __func__, link->remote_mac, &sll->sll_addr);
  

• return -EPROTO;
  

• }
• /* Current iteration of TSNis 0b000 only */
• if (ch->version)

• return -EPROTO;
  

• /* Invalid StreamID, should not have ended up here in the first

• * place (since we do DU only), if invalid sid, how did we find
  

• * the link?
  

• */
  

• if (!ch->sv)

• return -EPROTO;
  

• /* Check seqnr, if we have lost one frame, we _could_ insert an

• * empty frame, but since we have frame-guarantee from 802.1Qav,
  

• * we don't
  

• */
  

• seqnr = (link->last_seqnr + 1) & 0xff;
• if (header->seqnr != seqnr) {

• trace_printk("%llu: seqnr mismatch. Got %u, expected %u\n",
  

• 	     link->stream_id, header->seqnr, seqnr);
  

• return -EPROTO;
  

• }
• bytes = ntohs(header->sd_len);
• if (bytes == 0 || bytes > link->max_payload_size) {

• trace_printk("%llu: payload size larger than expected (%u, expected %u)\n",
  

• 	     link->stream_id, bytes, link->max_payload_size);
  

• return -EINVAL;
  

• }
• /* let shim validate header here as well */
• if (link->ops->validate_header &&

•    link->ops->validate_header(link, header) != 0)
  

• return -EINVAL;
  

• return 0;

+}

+int tsnh_assemble_du(struct tsn_link *link, struct avtpdu_header *header,

•      size_t bytes, u64 ts_pres_ns)
  

+{

• int ret = 0;
• void *data;
• if (!header || !link)

• return -EINVAL;
  

• tsnh_ch_init((struct avtp_ch *)header);
• header->cd = 0;
• header->sv = 1;
• header->mr = 0;
• header->gv = 0;
• header->tv = 1;
• header->tu = 0;
• header->avtp_timestamp = htonl(tsnh_avtp_timestamp(ts_pres_ns));
• header->gateway_info = 0;
• header->sd_len = htons(bytes);
• tsn_lock(link);
• if (!link->ops) {

• pr_err("%s: No available ops, cannot assemble data-unit\n",
  

•        __func__);
  

• ret = -EINVAL;
  

• goto unlock_out;
  

• }
• /* get pointer to where data starts */
• data = link->ops->get_payload_data(link, header);
• if (bytes > link->used_buffer_size) {

• pr_err("bytes > buffer_size (%zd >  %zd)\n",
  

•        bytes, link->used_buffer_size);
  

• ret = -EINVAL;
  

• goto unlock_out;
  

• }
• header->stream_id = cpu_to_be64(link->stream_id);
• header->seqnr = link->last_seqnr++;
• link->ops->assemble_header(link, header, bytes);
• tsn_unlock(link);
• /* payload */
• ret = tsn_buffer_read_net(link, data, bytes);
• if (ret != bytes) {

• pr_err("%s: Could not copy %zd bytes of data. Res: %d\n",
  

•        __func__, bytes, ret);
  

• /* FIXME: header cleanup */
  

• goto out;
  

• }
• ret = 0;

+out:

• return ret;

+unlock_out:

• tsn_unlock(link);
• return ret;

+}

+int _tsnh_handle_du(struct tsn_link *link, struct avtp_ch *ch) +{

• struct avtpdu_header *header = (struct avtpdu_header *)ch;
• void *data;
• u16 bytes;
• int ret;
• bytes = ntohs(header->sd_len);
• trace_tsn_du(link, bytes);
• /* bump seqnr */
• data = link->ops->get_payload_data(link, header);
• if (!data)

• return -EINVAL;
  

• link->last_seqnr = header->seqnr;
• ret = tsn_buffer_write_net(link, data, bytes);
• if (ret != bytes) {

• trace_printk("%s: Could not copy %u bytes of data. Res: %d\n",
  

• 	     __func__, bytes, ret);
  

• return ret;
  

• }
• return 0;

+} diff --git a/net/tsn/tsn_internal.h b/net/tsn/tsn_internal.h new file mode 100644 index 0000000..d0d2201 --- /dev/null +++ b/net/tsn/tsn_internal.h @@ -0,0 +1,383 @@ +/*

• • Copyright (C) 2015- Henrik Austad haustad@cisco.com
• • This program is free software; you can redistribute it and/or modify
• • it under the terms of the GNU General Public License as published by
• • the Free Software Foundation; either version 2 of the License, or
• • (at your option) any later version.
• • 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.
• */

+#ifndef _TSN_INTERNAL_H_ +#define _TSN_INTERNAL_H_ +#include <linux/tsn.h>

+#include <linux/mutex.h> +#include <linux/spinlock.h> +#include <linux/if_ether.h> +#include <linux/if_vlan.h>

+/* TODO:

• • • hide tsn-structs and provide handlers
• • • decouple config/net from core
• */

+struct avtpdu_header; +struct tsn_link; +struct tsn_shim_ops;

+#define IS_TSN_FRAME(x) (ntohs(x) == ETH_P_TSN) +#define IS_PTP_FRAME(x) (ntohs(x) == ETH_P_1588) +#define IS_1Q_FRAME(x) (ntohs(x) == ETH_P_8021Q)

+/**

• • tsn_add_link - create and add a new link to the system
• • Note: this will not enable the link, just allocate most of the data
• • required for the link. One notable exception being the buffer as we
• • can modify the buffersize before we start the link.
• • @param nic : the nic the link is tied to
• • @returns the new link
• */

+struct tsn_link *tsn_create_and_add_link(struct tsn_nic *nic);

+/**

• • tsn_get_stream_ids - write all current Stream IDs into the page.
• • @param page the page to write into
• • @param len size of page
• • @returns the number of bytes written
• */

+ssize_t tsn_get_stream_ids(char *page, ssize_t len);

+/**

• • tsn_find_by_stream_id - given a sid, find the corresponding link
• • @param sid stream_id
• • @returns tsn_link struct or NULL if not found
• */

+struct tsn_link *tsn_find_by_stream_id(u64 sid);

+/**

• • tsn_readd_link - make sure a link is moved to the correct bucket when
• • stream_id is updated
• • @link the TSN link
• • @old_key previous key for which it can be located in the hashmap
• */

+void tsn_readd_link(struct tsn_link *link, u64 old_key);

+/**

• • tsn_remove_link: cleanup and remove from internal storage
• • @link: the link to be removed
• */

+void tsn_remove_link(struct tsn_link *link);

+/**

• • tsn_prepare_link - make link ready for usage
• • Caller is happy with the different knobs, this will create the link and start
• • pushing the data.
• • Requirement:
• • • callback registered
• • • State set to either Talker or Listener
• • @param active link
• • @param the shim_ops to use for the new link
• • @return 0 on success, negative on error
• */

+int tsn_prepare_link(struct tsn_link *link, struct tsn_shim_ops *shim_ops); +int tsn_teardown_link(struct tsn_link *link);

+/**

• • tsn_set_external_buffer - force an update of the buffer
• • This will cause tsn_core to use an external buffer. If external
• • buffering is already in use, this has the effect of forcing an update
• • of the buffer.
• • This will cause tsn_core to swap buffers. The current buffer is
• • returned and the new is used in place.
• • Note: If the new buffer is NULL or buffer_size is less than
• • max_payload_size, the result can be interesting (by calling this
• • function, you claim to know what you are doing and should pass sane
• • values).
• • This can also be used if you need to resize the buffer in use.
• • Core will continue to use the tsn_shim_swap when the new buffer is
• • full.
• • @param link current link owning the buffer
• • @param buffer new buffer to use
• • @param buffer_size size of new buffer
• • @return old buffer
• */

+void *tsn_set_external_buffer(struct tsn_link *link, void *buffer,

• 	      size_t buffer_size);
  

+/**

• • tsn_buffer_write_net - write data *into* link->buffer from the network layer
• • Used by tsn_net and will typicall accept very small pieces of data.
• • @param link the link associated with the stream_id in the frame
• • @param src pointer to data in buffer
• • @param bytes number of bytes to copy
• • @return number of bytes copied into the buffer
• */

+int tsn_buffer_write_net(struct tsn_link *link, void *src, size_t bytes);

+/**

• • tsn_buffer_read_net - read data from link->buffer and give to network layer
• • When we send a frame, we grab data from the buffer and add it to the
• • sk_buff->data, this is primarily done by the Tx-subsystem in tsn_net
• • and is typically done in small chunks
• • @param link current link that holds the buffer
• • @param buffer the buffer to copy into, must be at least of size bytes
• • @param bytes number of bytes.
• • Note that this routine does NOT CARE about channels, samplesize etc,
• • it is a _pure_ copy that handles ringbuffer wraps etc.
• • This function have side-effects as it will update internal tsn_link
• • values and trigger refill() should the buffer run low.
• • @return Bytes copied into link->buffer, negative value upon error.
• */

+int tsn_buffer_read_net(struct tsn_link *link, void *buffer, size_t bytes);

+/**

• • tsn_core_running(): test if the link is running
• • By running, we mean that it is configured and a proper shim has been
• • loaded. It does *not* mean that we are currently pushing data in any
• • direction, see tsn_net_buffer_disabled() for this
• • @param struct tsn_link active link
• • @returns 1 if core is running
• */

+static inline int tsn_core_running(struct tsn_list *list) +{

• if (list)

• return atomic_read(&list->running);
  

• return 0;

+}

+/**

• • _tsn_buffer_used - how much of the buffer is filled with valid data
• • • assumes link->running in state running
• • • will ignore change changed state
• • We write to head, read from tail.
• */

+static inline size_t _tsn_buffer_used(struct tsn_link *link) +{

• return (link->head - link->tail) % link->used_buffer_size;

+}

+static inline void tsn_lock(struct tsn_link *link) +{

• spin_lock(&link->lock);

+}

+static inline void tsn_unlock(struct tsn_link *link) +{

• spin_unlock(&link->lock);

+}

+/* -----------------------------

• • ConfigFS handling
• */

+int tsn_configfs_init(struct tsn_list *tlist); +void tsn_configfs_exit(struct tsn_list *tlist);

+/* -----------------------------

• • TSN Header
• */

+static inline size_t tsnh_len(void) +{

• /* include 802.1Q tag */
• return sizeof(struct avtpdu_header);

+}

+static inline u16 tsnh_len_all(void) +{

• return (u16)tsnh_len() + ETH_HLEN;

+}

+/**

• • tsnh_payload_size_valid - if the entire payload is within size-limit
• • Ensure that max_payload_size and shim_header_size is within acceptable limits
• • We need both values to calculate the payload size when reserving
• • bandwidth, but only payload-size when instructing the shim to copy
• • out data for us.
• • @param max_payload_size requested payload to send in each frame (upper limit)
• • @return 0 on invalid, 1 on valid
• */

+static inline int tsnh_payload_size_valid(u16 max_payload_size,

• 			  u16 shim_hdr_size)
  

+{

• /* VLAN_ETH_ZLEN 64 */
• /* VLAN_ETH_FRAME_LEN 1518 */
• u32 framesize = max_payload_size + tsnh_len_all() + shim_hdr_size;
• return framesize >= VLAN_ETH_ZLEN && framesize <= VLAN_ETH_FRAME_LEN;

+}

+/**

• • _tsnh_validate_du_header - basic header validation
• • This expects the parameters to be present and the link-lock to be
• • held.
• • @param header header to verify
• • @param link owner of stream
• • @param socket_buffer
• • @return 0 on valid, negative on invalid/error
• */

+int _tsnh_validate_du_header(struct tsn_link *link, struct avtp_ch *ch,

• 	     struct sk_buff *skb);
  

+/**

• • tsnh_assemble_du - assemble header and copy data from buffer
• • This function will initialize the header and pass final init to
• • shim->assemble_header before copying data into the buffer.
• • It assumes that 'bytes' is a sane value, i.e. that it is a valid
• • multiple of number of channels, sample size etc.
• • @param link Current TSN link, also holds the buffer
• • @param header header to assemble for data
• • @param bytes Number of bytes to send in this frame
• • @param ts_pres_ns current for when the frame should be presented or

• •               considered valid by the receiving end. In
    

• •               nanoseconds since epoch, will be converted to gPTP
    

• •               compatible timestamp.
    

• • @return 0 on success, negative on error
• */

+int tsnh_assemble_du(struct tsn_link *link, struct avtpdu_header *header,

•      size_t bytes, u64 ts_pres_ns);
  

+/**

• • _tsnh_handle_du - handle incoming data and store to media-buffer
• • This assumes that the frame actually belongs to the link and that it
• • has passed basic validation.
• • It also expects the link lock to be held.
• • @param link Link associated with stream_id
• • @param header Header of incoming frame
• • @return number of bytes copied to buffer or negative on error
• */

+int _tsnh_handle_du(struct tsn_link *link, struct avtp_ch *ch);

+static inline struct avtp_ch *tsnh_ch_from_skb(struct sk_buff *skb) +{

• if (!skb)

• return NULL;
  

• if (!IS_TSN_FRAME(eth_hdr(skb)->h_proto))

• return NULL;
  

• return (struct avtp_ch *)skb->data;

+}

+/**

• • tsn_net_add_rx - add Rx handler for all NICs listed
• • @param list tsn_list to add Rx handler to
• • @return 0 on success, negative on error
• */

+int tsn_net_add_rx(struct tsn_list *list);

+/**

• • tsn_net_remove_rx - remove Rx-handlers for all tsn_nics
• • Go through all NICs and remove those Rx-handlers we have
• • registred. If someone else has added an Rx-handler to the NIC, we do
• • not touch it.
• • @param list list of all tsn_nics (with links)
• */

+void tsn_net_remove_rx(struct tsn_list *list);

+/**

• • tsn_net_open_tx - prepare all capable links for Tx
• • This will prepare all NICs for Tx, and those marked as 'capable'
• • will be initialized with DMA regions. Note that this is not the final
• • step for preparing for Tx, it is only when we have active links that
• • we know how much bandwidth we need and then can set the appropriate
• • idleSlope params etc.
• • @tlist: list of all available card
• • @return: negative on error, on success the number of prepared NICS

• •      are returned.
    

• */

+int tsn_net_prepare_tx(struct tsn_list *tlist);

+/**

• • tsn_net_disable_tx - disable Tx on card
• • This frees DMA-memory from capable NICs
• • @param tsn_list: link to all available NICs used by TSN
• */

+void tsn_net_disable_tx(struct tsn_list *tlist);

+/**

• • tsn_net_set_vlan - try to register the VLAN on the NIC
• • Some NICs will handle VLAN themselves, try to register this vlan with
• • the card to enable hw-support for Tx via this VLAN
• • @param: tsn_link the active link
• • @return: 0 on success, negative on error.
• */

+int tsn_net_set_vlan(struct tsn_link *link);

+/**

• • tsn_net_close - close down link properly
• • @param struct tsn_link * active link to close down
• */

+void tsn_net_close(struct tsn_link *link);

+/**

• • tsn_net_send_set - send a set of frames
• • We want to assemble a number of sk_buffs at a time and ship them off
• • in a single go and then go back to sleep. Pacing should be done by
• • hardware, or if we are in in_debug, we don't really care anyway
• • @param link : current TSN-link
• • @param num : the number of frames to create
• • @param ts_base_ns : base timestamp for when the frames should be

• •         considered valid
    

• • @param ts_delta_ns : time between each frame in the set
• */

+int tsn_net_send_set(struct tsn_link *link, size_t num, u64 ts_base_ns,

•      u64 ts_delta_ns);
  

+#endif /* _TSN_INTERNAL_H_ */ diff --git a/net/tsn/tsn_net.c b/net/tsn/tsn_net.c new file mode 100644 index 0000000..560e2fd --- /dev/null +++ b/net/tsn/tsn_net.c @@ -0,0 +1,403 @@ +/*

• • Network part of TSN
• • Copyright (C) 2015- Henrik Austad haustad@cisco.com
• • This program is free software; you can redistribute it and/or modify
• • it under the terms of the GNU General Public License as published by
• • the Free Software Foundation; either version 2 of the License, or
• • (at your option) any later version.
• • 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/kernel.h> +#include <linux/module.h> +#include <linux/netdevice.h> +#include <linux/socket.h> +#include <linux/skbuff.h> +#include <linux/if_vlan.h> +#include <linux/skbuff.h> +#include <net/sock.h>

+#include <linux/tsn.h> +#include <trace/events/tsn.h> +#include "tsn_internal.h"

+/**

• • tsn_rx_handler - consume all TSN-tagged frames and forward to tsn_link.
• • This handler, if it regsters properly, will consume all TSN-tagged
• • frames belonging to registered Stream IDs
• • Unknown StreamIDs will be passed through without being touched.
• • @param pskb sk_buff with incomign data
• • @returns RX_HANDLER_CONSUMED for TSN frames to known StreamIDs,

• •    RX_HANDLER_PASS for everything else.
    

• */

+static rx_handler_result_t tsn_rx_handler(struct sk_buff **pskb) +{

• struct sk_buff *skb = *pskb;
• const struct ethhdr *ethhdr = eth_hdr(skb);
• struct avtp_ch *ch;
• struct tsn_link *link;
• rx_handler_result_t ret = RX_HANDLER_PASS;
• ch = tsnh_ch_from_skb(skb);
• if (!ch)

• return RX_HANDLER_PASS;
  

• /* We do not (currently) touch control_data frames. */
• if (ch->cd)

• return RX_HANDLER_PASS;
  

• link = tsn_find_by_stream_id(be64_to_cpu(ch->stream_id));
• if (!link)

• return RX_HANDLER_PASS;
  

• tsn_lock(link);
• if (!tsn_link_is_on(link))

• goto out_unlock;
  

• /* If link->ops is not set yet, there's nothing we can do, just

• * ignore this frame
  

• */
  

• if (!link->ops)

• goto out_unlock;
  

• if (_tsnh_validate_du_header(link, ch, skb))

• goto out_unlock;
  

• trace_tsn_rx_handler(link, ethhdr, be64_to_cpu(ch->stream_id));
• /* Handle dataunit, if it failes, pass on the frame and let

• * userspace pick it up.
  

• */
  

• if (_tsnh_handle_du(link, ch) < 0)

• goto out_unlock;
  

• /* Done, data has been copied, free skb and return consumed */
• consume_skb(skb);
• ret = RX_HANDLER_CONSUMED;

+out_unlock:

• tsn_unlock(link);
• return ret;

+}

+int tsn_net_add_rx(struct tsn_list *tlist) +{

• struct tsn_nic *nic;
• if (!tlist)

• return -EINVAL;
  

• /* Setup receive handler for TSN traffic.

• *
  

• * Receive will happen all the time, once a link is active as a
  

• * Listener, we will add a hook into the receive-handler to
  

• * steer the frames to the correct link.
  

• *
  

• * We try to add Rx-handlers to all the card listed in tlist (we
  

• * assume core has filtered the NICs appropriatetly sothat only
  

• * TSN-capable cards are present).
  

• */
  

• mutex_lock(&tlist->lock);
• list_for_each_entry(nic, &tlist->head, list) {

• rtnl_lock();
  

• if (netdev_rx_handler_register(nic->dev, tsn_rx_handler, nic) < 0) {
  

• 	pr_err("%s: could not attach an Rx-handler to %s, this link will not be able to accept TSN traffic\n",
  

• 	       __func__, nic->name);
  

• 	rtnl_unlock();
  

• 	continue;
  

• }
  

• rtnl_unlock();
  

• pr_info("%s: attached rx-handler to %s\n",
  

• 	__func__, nic->name);
  

• nic->rx_registered = 1;
  

• }
• mutex_unlock(&tlist->lock);
• return 0;

+}

+void tsn_net_remove_rx(struct tsn_list *tlist) +{

• struct tsn_nic *nic;
• if (!tlist)

• return;
  

• mutex_lock(&tlist->lock);
• list_for_each_entry(nic, &tlist->head, list) {

• rtnl_lock();
  

• if (nic->rx_registered)
  

• 	netdev_rx_handler_unregister(nic->dev);
  

• rtnl_unlock();
  

• nic->rx_registered = 0;
  

• pr_info("%s: RX-handler for %s removed\n",
  

• 	__func__, nic->name);
  

• }
• mutex_unlock(&tlist->lock);

+}

+int tsn_net_prepare_tx(struct tsn_list *tlist) +{

• struct tsn_nic *nic;
• struct device *dev;
• int ret = 0;
• if (!tlist)

• return -EINVAL;
  

• mutex_lock(&tlist->lock);
• list_for_each_entry(nic, &tlist->head, list) {

• if (!nic)
  

• 	continue;
  

• if (!nic->capable)
  

• 	continue;
  

• if (!nic->dev->netdev_ops)
  

• 	continue;
  

• dev = nic->dev->dev.parent;
  

• nic->dma_mem = dma_alloc_coherent(dev, nic->dma_size,
  

• 				  &nic->dma_handle, GFP_KERNEL);
  

• if (!nic->dma_mem) {
  

• 	nic->capable = 0;
  

• 	nic->dma_size = 0;
  

• 	continue;
  

• }
  

• ret++;
  

• }
• mutex_unlock(&tlist->lock);
• pr_info("%s: configured %d cards to use DMA\n", __func__, ret);
• return ret;

+}

+void tsn_net_disable_tx(struct tsn_list *tlist) +{

• struct tsn_nic *nic;
• struct device *dev;
• int res = 0;
• if (!tlist)

• return;
  

• mutex_lock(&tlist->lock);
• list_for_each_entry(nic, &tlist->head, list) {

• if (nic->capable && nic->dma_mem) {
  

• 	dev = nic->dev->dev.parent;
  

• 	dma_free_coherent(dev, nic->dma_size, nic->dma_mem,
  

• 			  nic->dma_handle);
  

• 	res++;
  

• }
  

• }
• mutex_unlock(&tlist->lock);
• pr_info("%s: freed DMA regions from %d cards\n", __func__, res);

+}

+void tsn_net_close(struct tsn_link *link) +{

• /* struct tsn_rx_handler_data *rx_data; */
• /* Careful! we need to make sure that we actually succeeded in

• * registering the handler in open unless we want to unregister
  

• * some random rx_handler..
  

• */
  

• if (!link->estype_talker) {

• ;
  

• /* Make sure we notify rx-handler so it doesn't write
  

•  * into NULL
  

•  */
  

• }

+}

+int tsn_net_set_vlan(struct tsn_link *link) +{

• int err;
• struct tsn_nic *nic = link->nic;
• const struct net_device_ops *ops = nic->dev->netdev_ops;
• int vf = 2;
• u16 vlan = link->vlan_id;
• u8 qos = link->class_a ? link->pcp_a : link->pcp_b;
• pr_info("%s:%s Setting vlan=%u,vf=%d,qos=%u\n",

• __func__, nic->name, vlan, vf, qos);
  

• if (ops->ndo_set_vf_vlan) {

• err = ops->ndo_set_vf_vlan(nic->dev, vf, vlan, qos);
  

• if (err != 0) {
  

• 	pr_err("%s:%s could not set VLAN to %u, got %d\n",
  

• 	       __func__,  nic->name, vlan, err);
  

• 	return -EINVAL;
  

• }
  

• return 0;
  

• }
• return -1;

+}

+static inline u16 _get_8021q_vid(struct tsn_link *link) +{

• u16 pcp = link->class_a ? link->pcp_a : link->pcp_b;
• /* If not explicitly provided, use SR_PVID 0x2*/
• return (link->vlan_id & VLAN_VID_MASK) | ((pcp & 0x7) << 13);

+}

+/* create and initialize a sk_buff with appropriate TSN Header values

• • layout of frame:
• • • Ethernet header
• • dst (6) | src (6) | 802.1Q (4) | EtherType (2)
• • • 1722 (sizeof struct avtpdu)
• • • payload data
• • • type header (e.g. iec61883-6 hdr)
• • • payload data
• • Required size:
• • Ethernet: 18 -> VLAN_ETH_HLEN
• • 1722: tsnh_len()
• • payload: shim_hdr_size + data_bytes
• • Note:
• • • seqnr is not set
• • • payload is not set
• */

+static struct sk_buff *_skbuf_create_init(struct tsn_link *link,

• 			  size_t data_bytes,
  

• 			  size_t shim_hdr_size,
  

• 			  u64 ts_pres_ns, u8 more)
  

+{

• struct sk_buff *skb = NULL;
• struct avtpdu_header *avtpdu;
• struct net_device *netdev = link->nic->dev;
• int queue_idx;
• int res = 0;
• int hard_hdr_len;
• /* length is size of AVTPDU + data

• * +-----+ <-- head
  

• * | - link layer header
  

• * | - 1722 header (avtpdu_header)
  

• * +-----+ <-- data
  

• * | - shim_header
  

• * | - data
  

• * +-----+ <-- tail
  

• * |
  

• * +-----+ <--end
  

• * We stuff all of TSN-related
  

• * headers in the data-segment to make it easy
  

• */
  

• size_t hdr_len = VLAN_ETH_HLEN;
• size_t avtpdu_len = tsnh_len() + shim_hdr_size + data_bytes;
• skb = alloc_skb(hdr_len + avtpdu_len + netdev->needed_tailroom,

• 	GFP_ATOMIC | GFP_DMA);
  

• if (!skb)

• return NULL;
  

• skb_reserve(skb, hdr_len);
• skb->protocol = htons(ETH_P_TSN);
• skb->pkt_type = PACKET_OUTGOING;
• skb->priority = (link->class_a ? link->pcp_a : link->pcp_b);
• skb->dev = link->nic->dev;
• skb_shinfo(skb)->tx_flags |= SKBTX_HW_TSTAMP;
• skb->xmit_more = (more > 0 ? 1 : 0);
• skb_set_mac_header(skb, 0);
• /* We are using a ethernet-type frame (even though we could send

• * TSN over other medium.
  

• *
  

• * - skb_push(skb, ETH_HLEN)
  

• * - set header htons(header)
  

• * - set source addr (netdev mac addr)
  

• * - set dest addr
  

• * - return ETH_HLEN
  

• */
  

• hard_hdr_len = dev_hard_header(skb, skb->dev, ETH_P_TSN,

• 		       link->remote_mac, NULL, 6);
  

• skb = vlan_insert_tag(skb, htons(ETH_P_8021Q), _get_8021q_vid(link));
• if (!skb) {

• pr_err("%s: could not insert tag in buffer, aborting\n",
  

•        __func__);
  

• return NULL;
  

• }
• /* tsnh_assemble_du() will deref avtpdu to find start of data

• * segment and use that, this is to update the skb
  

• * appropriately.
  

• *
  

• * tsnh_assemble_du() will grab tsn-lock before updating link
  

• */
  

• avtpdu = (struct avtpdu_header *)skb_put(skb, avtpdu_len);
• res = tsnh_assemble_du(link, avtpdu, data_bytes, ts_pres_ns);
• if (res < 0) {

• pr_err("%s: Error initializing header (-> %d) , we are in an inconsistent state!\n",
  

•        __func__, res);
  

• kfree_skb(skb);
  

• return NULL;
  

• }
• /* FIXME: Find a suitable Tx-queue

• *
  

• * For igb, this returns -1
  

• */
  

• queue_idx = sk_tx_queue_get(skb->sk);
• if (queue_idx < 0 || queue_idx >= netdev->real_num_tx_queues)

• queue_idx = 0;
  

• skb_set_queue_mapping(skb, queue_idx);
• skb->queue_mapping = 0;
• skb->csum = skb_checksum(skb, 0, hdr_len + data_bytes, 0);
• return skb;

+}

+/**

• • Send a set of frames as efficiently as possible
• */

+int tsn_net_send_set(struct tsn_link *link, size_t num, u64 ts_base_ns,

•      u64 ts_delta_ns)
  

+{

• struct sk_buff *skb;
• struct net_device *dev;
• size_t data_size;
• int res;
• struct netdev_queue *txq;
• u64 ts_pres_ns = ts_base_ns;
• if (!link)

• return -EINVAL;
  

• dev = link->nic->dev;
• /* create and init sk_buff_head */
• while (num-- > 0) {

• data_size = tsn_shim_get_framesize(link);
  

• skb = _skbuf_create_init(link, data_size,
  

• 			 tsn_shim_get_hdr_size(link),
  

• 			 ts_pres_ns, (num > 0));
  

• if (!skb) {
  

• 	pr_err("%s: could not allocate memory for skb\n",
  

• 	       __func__);
  

• 	return -ENOMEM;
  

• }
  

• trace_tsn_pre_tx(link, skb, data_size);
  

• txq = skb_get_tx_queue(dev, skb);
  

• if (!txq) {
  

• 	pr_err("%s: Could not get tx_queue, dropping sending\n",
  

• 	       __func__);
  

• 	kfree_skb(skb);
  

• 	return -EINVAL;
  

• }
  

• res = netdev_start_xmit(skb, dev, txq, (num > 0));
  

• if (res != NETDEV_TX_OK) {
  

• 	pr_err("%s: Tx FAILED\n", __func__);
  

• 	return res;
  

• }
  

• ts_pres_ns += ts_delta_ns;
  

• }
• return 0;

+}

2.7.4