net/ncsi: Resource management
NCSI spec (DSP0222) defines several objects: package, channel, mode,
filter, version and statistics etc. This introduces the data structs
to represent those objects and implement functions to manage them.
Also, this introduces CONFIG_NET_NCSI for the newly implemented NCSI
stack.
* The user (e.g. netdev driver) dereference NCSI device by
"struct ncsi_dev", which is embedded to "struct ncsi_dev_priv".
The later one is used by NCSI stack internally.
* Every NCSI device can have multiple packages simultaneously, up
to 8 packages. It's represented by "struct ncsi_package" and
identified by 3-bits ID.
* Every NCSI package can have multiple channels, up to 32. It's
represented by "struct ncsi_channel" and identified by 5-bits ID.
* Every NCSI channel has version, statistics, various modes and
filters. They are represented by "struct ncsi_channel_version",
"struct ncsi_channel_stats", "struct ncsi_channel_mode" and
"struct ncsi_channel_filter" separately.
* Apart from AEN (Asynchronous Event Notification), the NCSI stack
works in terms of command and response. This introduces "struct
ncsi_req" to represent a complete NCSI transaction made of NCSI
request and response.
link: https://www.dmtf.org/sites/default/files/standards/documents/DSP0222_1.1.0.pdf
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ncsi/ncsi-manage.c b/net/ncsi/ncsi-manage.c
new file mode 100644
index 0000000..0e28ed8
--- /dev/null
+++ b/net/ncsi/ncsi-manage.c
@@ -0,0 +1,436 @@
+/*
+ * Copyright Gavin Shan, IBM Corporation 2016.
+ *
+ * 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.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/netdevice.h>
+#include <linux/skbuff.h>
+#include <linux/netlink.h>
+
+#include <net/ncsi.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+
+#include "internal.h"
+
+LIST_HEAD(ncsi_dev_list);
+DEFINE_SPINLOCK(ncsi_dev_lock);
+
+static inline int ncsi_filter_size(int table)
+{
+ int sizes[] = { 2, 6, 6, 6 };
+
+ BUILD_BUG_ON(ARRAY_SIZE(sizes) != NCSI_FILTER_MAX);
+ if (table < NCSI_FILTER_BASE || table >= NCSI_FILTER_MAX)
+ return -EINVAL;
+
+ return sizes[table];
+}
+
+int ncsi_find_filter(struct ncsi_channel *nc, int table, void *data)
+{
+ struct ncsi_channel_filter *ncf;
+ void *bitmap;
+ int index, size;
+ unsigned long flags;
+
+ ncf = nc->filters[table];
+ if (!ncf)
+ return -ENXIO;
+
+ size = ncsi_filter_size(table);
+ if (size < 0)
+ return size;
+
+ spin_lock_irqsave(&nc->lock, flags);
+ bitmap = (void *)&ncf->bitmap;
+ index = -1;
+ while ((index = find_next_bit(bitmap, ncf->total, index + 1))
+ < ncf->total) {
+ if (!memcmp(ncf->data + size * index, data, size)) {
+ spin_unlock_irqrestore(&nc->lock, flags);
+ return index;
+ }
+ }
+ spin_unlock_irqrestore(&nc->lock, flags);
+
+ return -ENOENT;
+}
+
+int ncsi_add_filter(struct ncsi_channel *nc, int table, void *data)
+{
+ struct ncsi_channel_filter *ncf;
+ int index, size;
+ void *bitmap;
+ unsigned long flags;
+
+ size = ncsi_filter_size(table);
+ if (size < 0)
+ return size;
+
+ index = ncsi_find_filter(nc, table, data);
+ if (index >= 0)
+ return index;
+
+ ncf = nc->filters[table];
+ if (!ncf)
+ return -ENODEV;
+
+ spin_lock_irqsave(&nc->lock, flags);
+ bitmap = (void *)&ncf->bitmap;
+ do {
+ index = find_next_zero_bit(bitmap, ncf->total, 0);
+ if (index >= ncf->total) {
+ spin_unlock_irqrestore(&nc->lock, flags);
+ return -ENOSPC;
+ }
+ } while (test_and_set_bit(index, bitmap));
+
+ memcpy(ncf->data + size * index, data, size);
+ spin_unlock_irqrestore(&nc->lock, flags);
+
+ return index;
+}
+
+int ncsi_remove_filter(struct ncsi_channel *nc, int table, int index)
+{
+ struct ncsi_channel_filter *ncf;
+ int size;
+ void *bitmap;
+ unsigned long flags;
+
+ size = ncsi_filter_size(table);
+ if (size < 0)
+ return size;
+
+ ncf = nc->filters[table];
+ if (!ncf || index >= ncf->total)
+ return -ENODEV;
+
+ spin_lock_irqsave(&nc->lock, flags);
+ bitmap = (void *)&ncf->bitmap;
+ if (test_and_clear_bit(index, bitmap))
+ memset(ncf->data + size * index, 0, size);
+ spin_unlock_irqrestore(&nc->lock, flags);
+
+ return 0;
+}
+
+struct ncsi_channel *ncsi_find_channel(struct ncsi_package *np,
+ unsigned char id)
+{
+ struct ncsi_channel *nc;
+
+ NCSI_FOR_EACH_CHANNEL(np, nc) {
+ if (nc->id == id)
+ return nc;
+ }
+
+ return NULL;
+}
+
+struct ncsi_channel *ncsi_add_channel(struct ncsi_package *np, unsigned char id)
+{
+ struct ncsi_channel *nc, *tmp;
+ int index;
+ unsigned long flags;
+
+ nc = kzalloc(sizeof(*nc), GFP_ATOMIC);
+ if (!nc)
+ return NULL;
+
+ nc->id = id;
+ nc->package = np;
+ nc->state = NCSI_CHANNEL_INACTIVE;
+ spin_lock_init(&nc->lock);
+ for (index = 0; index < NCSI_CAP_MAX; index++)
+ nc->caps[index].index = index;
+ for (index = 0; index < NCSI_MODE_MAX; index++)
+ nc->modes[index].index = index;
+
+ spin_lock_irqsave(&np->lock, flags);
+ tmp = ncsi_find_channel(np, id);
+ if (tmp) {
+ spin_unlock_irqrestore(&np->lock, flags);
+ kfree(nc);
+ return tmp;
+ }
+
+ list_add_tail_rcu(&nc->node, &np->channels);
+ np->channel_num++;
+ spin_unlock_irqrestore(&np->lock, flags);
+
+ return nc;
+}
+
+static void ncsi_remove_channel(struct ncsi_channel *nc)
+{
+ struct ncsi_package *np = nc->package;
+ struct ncsi_channel_filter *ncf;
+ unsigned long flags;
+ int i;
+
+ /* Release filters */
+ spin_lock_irqsave(&nc->lock, flags);
+ for (i = 0; i < NCSI_FILTER_MAX; i++) {
+ ncf = nc->filters[i];
+ if (!ncf)
+ continue;
+
+ nc->filters[i] = NULL;
+ kfree(ncf);
+ }
+
+ nc->state = NCSI_CHANNEL_INACTIVE;
+ spin_unlock_irqrestore(&nc->lock, flags);
+
+ /* Remove and free channel */
+ spin_lock_irqsave(&np->lock, flags);
+ list_del_rcu(&nc->node);
+ np->channel_num--;
+ spin_unlock_irqrestore(&np->lock, flags);
+
+ kfree(nc);
+}
+
+struct ncsi_package *ncsi_find_package(struct ncsi_dev_priv *ndp,
+ unsigned char id)
+{
+ struct ncsi_package *np;
+
+ NCSI_FOR_EACH_PACKAGE(ndp, np) {
+ if (np->id == id)
+ return np;
+ }
+
+ return NULL;
+}
+
+struct ncsi_package *ncsi_add_package(struct ncsi_dev_priv *ndp,
+ unsigned char id)
+{
+ struct ncsi_package *np, *tmp;
+ unsigned long flags;
+
+ np = kzalloc(sizeof(*np), GFP_ATOMIC);
+ if (!np)
+ return NULL;
+
+ np->id = id;
+ np->ndp = ndp;
+ spin_lock_init(&np->lock);
+ INIT_LIST_HEAD(&np->channels);
+
+ spin_lock_irqsave(&ndp->lock, flags);
+ tmp = ncsi_find_package(ndp, id);
+ if (tmp) {
+ spin_unlock_irqrestore(&ndp->lock, flags);
+ kfree(np);
+ return tmp;
+ }
+
+ list_add_tail_rcu(&np->node, &ndp->packages);
+ ndp->package_num++;
+ spin_unlock_irqrestore(&ndp->lock, flags);
+
+ return np;
+}
+
+void ncsi_remove_package(struct ncsi_package *np)
+{
+ struct ncsi_dev_priv *ndp = np->ndp;
+ struct ncsi_channel *nc, *tmp;
+ unsigned long flags;
+
+ /* Release all child channels */
+ list_for_each_entry_safe(nc, tmp, &np->channels, node)
+ ncsi_remove_channel(nc);
+
+ /* Remove and free package */
+ spin_lock_irqsave(&ndp->lock, flags);
+ list_del_rcu(&np->node);
+ ndp->package_num--;
+ spin_unlock_irqrestore(&ndp->lock, flags);
+
+ kfree(np);
+}
+
+void ncsi_find_package_and_channel(struct ncsi_dev_priv *ndp,
+ unsigned char id,
+ struct ncsi_package **np,
+ struct ncsi_channel **nc)
+{
+ struct ncsi_package *p;
+ struct ncsi_channel *c;
+
+ p = ncsi_find_package(ndp, NCSI_PACKAGE_INDEX(id));
+ c = p ? ncsi_find_channel(p, NCSI_CHANNEL_INDEX(id)) : NULL;
+
+ if (np)
+ *np = p;
+ if (nc)
+ *nc = c;
+}
+
+/* For two consecutive NCSI commands, the packet IDs shouldn't
+ * be same. Otherwise, the bogus response might be replied. So
+ * the available IDs are allocated in round-robin fashion.
+ */
+struct ncsi_request *ncsi_alloc_request(struct ncsi_dev_priv *ndp, bool driven)
+{
+ struct ncsi_request *nr = NULL;
+ int i, limit = ARRAY_SIZE(ndp->requests);
+ unsigned long flags;
+
+ /* Check if there is one available request until the ceiling */
+ spin_lock_irqsave(&ndp->lock, flags);
+ for (i = ndp->request_id; !nr && i < limit; i++) {
+ if (ndp->requests[i].used)
+ continue;
+
+ nr = &ndp->requests[i];
+ nr->used = true;
+ nr->driven = driven;
+ if (++ndp->request_id >= limit)
+ ndp->request_id = 0;
+ }
+
+ /* Fail back to check from the starting cursor */
+ for (i = 0; !nr && i < ndp->request_id; i++) {
+ if (ndp->requests[i].used)
+ continue;
+
+ nr = &ndp->requests[i];
+ nr->used = true;
+ nr->driven = driven;
+ if (++ndp->request_id >= limit)
+ ndp->request_id = 0;
+ }
+ spin_unlock_irqrestore(&ndp->lock, flags);
+
+ return nr;
+}
+
+void ncsi_free_request(struct ncsi_request *nr)
+{
+ struct ncsi_dev_priv *ndp = nr->ndp;
+ struct sk_buff *cmd, *rsp;
+ unsigned long flags;
+
+ if (nr->enabled) {
+ nr->enabled = false;
+ del_timer_sync(&nr->timer);
+ }
+
+ spin_lock_irqsave(&ndp->lock, flags);
+ cmd = nr->cmd;
+ rsp = nr->rsp;
+ nr->cmd = NULL;
+ nr->rsp = NULL;
+ nr->used = false;
+ spin_unlock_irqrestore(&ndp->lock, flags);
+
+ /* Release command and response */
+ consume_skb(cmd);
+ consume_skb(rsp);
+}
+
+struct ncsi_dev *ncsi_find_dev(struct net_device *dev)
+{
+ struct ncsi_dev_priv *ndp;
+
+ NCSI_FOR_EACH_DEV(ndp) {
+ if (ndp->ndev.dev == dev)
+ return &ndp->ndev;
+ }
+
+ return NULL;
+}
+
+static void ncsi_request_timeout(unsigned long data)
+{
+ struct ncsi_request *nr = (struct ncsi_request *)data;
+ struct ncsi_dev_priv *ndp = nr->ndp;
+ unsigned long flags;
+
+ /* If the request already had associated response,
+ * let the response handler to release it.
+ */
+ spin_lock_irqsave(&ndp->lock, flags);
+ nr->enabled = false;
+ if (nr->rsp || !nr->cmd) {
+ spin_unlock_irqrestore(&ndp->lock, flags);
+ return;
+ }
+ spin_unlock_irqrestore(&ndp->lock, flags);
+
+ /* Release the request */
+ ncsi_free_request(nr);
+}
+
+struct ncsi_dev *ncsi_register_dev(struct net_device *dev,
+ void (*handler)(struct ncsi_dev *ndev))
+{
+ struct ncsi_dev_priv *ndp;
+ struct ncsi_dev *nd;
+ unsigned long flags;
+ int i;
+
+ /* Check if the device has been registered or not */
+ nd = ncsi_find_dev(dev);
+ if (nd)
+ return nd;
+
+ /* Create NCSI device */
+ ndp = kzalloc(sizeof(*ndp), GFP_ATOMIC);
+ if (!ndp)
+ return NULL;
+
+ nd = &ndp->ndev;
+ nd->state = ncsi_dev_state_registered;
+ nd->dev = dev;
+ nd->handler = handler;
+
+ /* Initialize private NCSI device */
+ spin_lock_init(&ndp->lock);
+ INIT_LIST_HEAD(&ndp->packages);
+ ndp->request_id = 0;
+ for (i = 0; i < ARRAY_SIZE(ndp->requests); i++) {
+ ndp->requests[i].id = i;
+ ndp->requests[i].ndp = ndp;
+ setup_timer(&ndp->requests[i].timer,
+ ncsi_request_timeout,
+ (unsigned long)&ndp->requests[i]);
+ }
+
+ spin_lock_irqsave(&ncsi_dev_lock, flags);
+ list_add_tail_rcu(&ndp->node, &ncsi_dev_list);
+ spin_unlock_irqrestore(&ncsi_dev_lock, flags);
+
+ return nd;
+}
+EXPORT_SYMBOL_GPL(ncsi_register_dev);
+
+void ncsi_unregister_dev(struct ncsi_dev *nd)
+{
+ struct ncsi_dev_priv *ndp = TO_NCSI_DEV_PRIV(nd);
+ struct ncsi_package *np, *tmp;
+ unsigned long flags;
+
+ list_for_each_entry_safe(np, tmp, &ndp->packages, node)
+ ncsi_remove_package(np);
+
+ spin_lock_irqsave(&ncsi_dev_lock, flags);
+ list_del_rcu(&ndp->node);
+ spin_unlock_irqrestore(&ncsi_dev_lock, flags);
+
+ kfree(ndp);
+}
+EXPORT_SYMBOL_GPL(ncsi_unregister_dev);