--- /dev/null
+/*
+ * ALSA sequencer Ports
+ * Copyright (c) 1998 by Frank van de Pol <fvdpol@coil.demon.nl>
+ * Jaroslav Kysela <perex@perex.cz>
+ *
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ */
+
+#include <sound/core.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include "seq_system.h"
+#include "seq_ports.h"
+#include "seq_clientmgr.h"
+
+/*
+
+ registration of client ports
+
+ */
+
+
+/*
+
+NOTE: the current implementation of the port structure as a linked list is
+not optimal for clients that have many ports. For sending messages to all
+subscribers of a port we first need to find the address of the port
+structure, which means we have to traverse the list. A direct access table
+(array) would be better, but big preallocated arrays waste memory.
+
+Possible actions:
+
+1) leave it this way, a client does normaly does not have more than a few
+ports
+
+2) replace the linked list of ports by a array of pointers which is
+dynamicly kmalloced. When a port is added or deleted we can simply allocate
+a new array, copy the corresponding pointers, and delete the old one. We
+then only need a pointer to this array, and an integer that tells us how
+much elements are in array.
+
+*/
+
+/* return pointer to port structure - port is locked if found */
+struct snd_seq_client_port *snd_seq_port_use_ptr(struct snd_seq_client *client,
+ int num)
+{
+ struct snd_seq_client_port *port;
+
+ if (client == NULL)
+ return NULL;
+ read_lock(&client->ports_lock);
+ list_for_each_entry(port, &client->ports_list_head, list) {
+ if (port->addr.port == num) {
+ if (port->closing)
+ break; /* deleting now */
+ snd_use_lock_use(&port->use_lock);
+ read_unlock(&client->ports_lock);
+ return port;
+ }
+ }
+ read_unlock(&client->ports_lock);
+ return NULL; /* not found */
+}
+
+
+/* search for the next port - port is locked if found */
+struct snd_seq_client_port *snd_seq_port_query_nearest(struct snd_seq_client *client,
+ struct snd_seq_port_info *pinfo)
+{
+ int num;
+ struct snd_seq_client_port *port, *found;
+
+ num = pinfo->addr.port;
+ found = NULL;
+ read_lock(&client->ports_lock);
+ list_for_each_entry(port, &client->ports_list_head, list) {
+ if (port->addr.port < num)
+ continue;
+ if (port->addr.port == num) {
+ found = port;
+ break;
+ }
+ if (found == NULL || port->addr.port < found->addr.port)
+ found = port;
+ }
+ if (found) {
+ if (found->closing)
+ found = NULL;
+ else
+ snd_use_lock_use(&found->use_lock);
+ }
+ read_unlock(&client->ports_lock);
+ return found;
+}
+
+
+/* initialize snd_seq_port_subs_info */
+static void port_subs_info_init(struct snd_seq_port_subs_info *grp)
+{
+ INIT_LIST_HEAD(&grp->list_head);
+ grp->count = 0;
+ grp->exclusive = 0;
+ rwlock_init(&grp->list_lock);
+ init_rwsem(&grp->list_mutex);
+ grp->open = NULL;
+ grp->close = NULL;
+}
+
+
+/* create a port, port number is returned (-1 on failure) */
+struct snd_seq_client_port *snd_seq_create_port(struct snd_seq_client *client,
+ int port)
+{
+ unsigned long flags;
+ struct snd_seq_client_port *new_port, *p;
+ int num = -1;
+
+ /* sanity check */
+ if (snd_BUG_ON(!client))
+ return NULL;
+
+ if (client->num_ports >= SNDRV_SEQ_MAX_PORTS) {
+ pr_warn("ALSA: seq: too many ports for client %d\n", client->number);
+ return NULL;
+ }
+
+ /* create a new port */
+ new_port = kzalloc(sizeof(*new_port), GFP_KERNEL);
+ if (!new_port)
+ return NULL; /* failure, out of memory */
+ /* init port data */
+ new_port->addr.client = client->number;
+ new_port->addr.port = -1;
+ new_port->owner = THIS_MODULE;
+ sprintf(new_port->name, "port-%d", num);
+ snd_use_lock_init(&new_port->use_lock);
+ port_subs_info_init(&new_port->c_src);
+ port_subs_info_init(&new_port->c_dest);
+
+ num = port >= 0 ? port : 0;
+ mutex_lock(&client->ports_mutex);
+ write_lock_irqsave(&client->ports_lock, flags);
+ list_for_each_entry(p, &client->ports_list_head, list) {
+ if (p->addr.port > num)
+ break;
+ if (port < 0) /* auto-probe mode */
+ num = p->addr.port + 1;
+ }
+ /* insert the new port */
+ list_add_tail(&new_port->list, &p->list);
+ client->num_ports++;
+ new_port->addr.port = num; /* store the port number in the port */
+ write_unlock_irqrestore(&client->ports_lock, flags);
+ mutex_unlock(&client->ports_mutex);
+ sprintf(new_port->name, "port-%d", num);
+
+ return new_port;
+}
+
+/* */
+enum group_type {
+ SRC_LIST, DEST_LIST
+};
+
+static int subscribe_port(struct snd_seq_client *client,
+ struct snd_seq_client_port *port,
+ struct snd_seq_port_subs_info *grp,
+ struct snd_seq_port_subscribe *info, int send_ack);
+static int unsubscribe_port(struct snd_seq_client *client,
+ struct snd_seq_client_port *port,
+ struct snd_seq_port_subs_info *grp,
+ struct snd_seq_port_subscribe *info, int send_ack);
+
+
+static struct snd_seq_client_port *get_client_port(struct snd_seq_addr *addr,
+ struct snd_seq_client **cp)
+{
+ struct snd_seq_client_port *p;
+ *cp = snd_seq_client_use_ptr(addr->client);
+ if (*cp) {
+ p = snd_seq_port_use_ptr(*cp, addr->port);
+ if (! p) {
+ snd_seq_client_unlock(*cp);
+ *cp = NULL;
+ }
+ return p;
+ }
+ return NULL;
+}
+
+/*
+ * remove all subscribers on the list
+ * this is called from port_delete, for each src and dest list.
+ */
+static void clear_subscriber_list(struct snd_seq_client *client,
+ struct snd_seq_client_port *port,
+ struct snd_seq_port_subs_info *grp,
+ int grptype)
+{
+ struct list_head *p, *n;
+
+ list_for_each_safe(p, n, &grp->list_head) {
+ struct snd_seq_subscribers *subs;
+ struct snd_seq_client *c;
+ struct snd_seq_client_port *aport;
+
+ if (grptype == SRC_LIST) {
+ subs = list_entry(p, struct snd_seq_subscribers, src_list);
+ aport = get_client_port(&subs->info.dest, &c);
+ } else {
+ subs = list_entry(p, struct snd_seq_subscribers, dest_list);
+ aport = get_client_port(&subs->info.sender, &c);
+ }
+ list_del(p);
+ unsubscribe_port(client, port, grp, &subs->info, 0);
+ if (!aport) {
+ /* looks like the connected port is being deleted.
+ * we decrease the counter, and when both ports are deleted
+ * remove the subscriber info
+ */
+ if (atomic_dec_and_test(&subs->ref_count))
+ kfree(subs);
+ } else {
+ /* ok we got the connected port */
+ struct snd_seq_port_subs_info *agrp;
+ agrp = (grptype == SRC_LIST) ? &aport->c_dest : &aport->c_src;
+ down_write(&agrp->list_mutex);
+ if (grptype == SRC_LIST)
+ list_del(&subs->dest_list);
+ else
+ list_del(&subs->src_list);
+ up_write(&agrp->list_mutex);
+ unsubscribe_port(c, aport, agrp, &subs->info, 1);
+ kfree(subs);
+ snd_seq_port_unlock(aport);
+ snd_seq_client_unlock(c);
+ }
+ }
+}
+
+/* delete port data */
+static int port_delete(struct snd_seq_client *client,
+ struct snd_seq_client_port *port)
+{
+ /* set closing flag and wait for all port access are gone */
+ port->closing = 1;
+ snd_use_lock_sync(&port->use_lock);
+
+ /* clear subscribers info */
+ clear_subscriber_list(client, port, &port->c_src, SRC_LIST);
+ clear_subscriber_list(client, port, &port->c_dest, DEST_LIST);
+
+ if (port->private_free)
+ port->private_free(port->private_data);
+
+ snd_BUG_ON(port->c_src.count != 0);
+ snd_BUG_ON(port->c_dest.count != 0);
+
+ kfree(port);
+ return 0;
+}
+
+
+/* delete a port with the given port id */
+int snd_seq_delete_port(struct snd_seq_client *client, int port)
+{
+ unsigned long flags;
+ struct snd_seq_client_port *found = NULL, *p;
+
+ mutex_lock(&client->ports_mutex);
+ write_lock_irqsave(&client->ports_lock, flags);
+ list_for_each_entry(p, &client->ports_list_head, list) {
+ if (p->addr.port == port) {
+ /* ok found. delete from the list at first */
+ list_del(&p->list);
+ client->num_ports--;
+ found = p;
+ break;
+ }
+ }
+ write_unlock_irqrestore(&client->ports_lock, flags);
+ mutex_unlock(&client->ports_mutex);
+ if (found)
+ return port_delete(client, found);
+ else
+ return -ENOENT;
+}
+
+/* delete the all ports belonging to the given client */
+int snd_seq_delete_all_ports(struct snd_seq_client *client)
+{
+ unsigned long flags;
+ struct list_head deleted_list;
+ struct snd_seq_client_port *port, *tmp;
+
+ /* move the port list to deleted_list, and
+ * clear the port list in the client data.
+ */
+ mutex_lock(&client->ports_mutex);
+ write_lock_irqsave(&client->ports_lock, flags);
+ if (! list_empty(&client->ports_list_head)) {
+ list_add(&deleted_list, &client->ports_list_head);
+ list_del_init(&client->ports_list_head);
+ } else {
+ INIT_LIST_HEAD(&deleted_list);
+ }
+ client->num_ports = 0;
+ write_unlock_irqrestore(&client->ports_lock, flags);
+
+ /* remove each port in deleted_list */
+ list_for_each_entry_safe(port, tmp, &deleted_list, list) {
+ list_del(&port->list);
+ snd_seq_system_client_ev_port_exit(port->addr.client, port->addr.port);
+ port_delete(client, port);
+ }
+ mutex_unlock(&client->ports_mutex);
+ return 0;
+}
+
+/* set port info fields */
+int snd_seq_set_port_info(struct snd_seq_client_port * port,
+ struct snd_seq_port_info * info)
+{
+ if (snd_BUG_ON(!port || !info))
+ return -EINVAL;
+
+ /* set port name */
+ if (info->name[0])
+ strlcpy(port->name, info->name, sizeof(port->name));
+
+ /* set capabilities */
+ port->capability = info->capability;
+
+ /* get port type */
+ port->type = info->type;
+
+ /* information about supported channels/voices */
+ port->midi_channels = info->midi_channels;
+ port->midi_voices = info->midi_voices;
+ port->synth_voices = info->synth_voices;
+
+ /* timestamping */
+ port->timestamping = (info->flags & SNDRV_SEQ_PORT_FLG_TIMESTAMP) ? 1 : 0;
+ port->time_real = (info->flags & SNDRV_SEQ_PORT_FLG_TIME_REAL) ? 1 : 0;
+ port->time_queue = info->time_queue;
+
+ return 0;
+}
+
+/* get port info fields */
+int snd_seq_get_port_info(struct snd_seq_client_port * port,
+ struct snd_seq_port_info * info)
+{
+ if (snd_BUG_ON(!port || !info))
+ return -EINVAL;
+
+ /* get port name */
+ strlcpy(info->name, port->name, sizeof(info->name));
+
+ /* get capabilities */
+ info->capability = port->capability;
+
+ /* get port type */
+ info->type = port->type;
+
+ /* information about supported channels/voices */
+ info->midi_channels = port->midi_channels;
+ info->midi_voices = port->midi_voices;
+ info->synth_voices = port->synth_voices;
+
+ /* get subscriber counts */
+ info->read_use = port->c_src.count;
+ info->write_use = port->c_dest.count;
+
+ /* timestamping */
+ info->flags = 0;
+ if (port->timestamping) {
+ info->flags |= SNDRV_SEQ_PORT_FLG_TIMESTAMP;
+ if (port->time_real)
+ info->flags |= SNDRV_SEQ_PORT_FLG_TIME_REAL;
+ info->time_queue = port->time_queue;
+ }
+
+ return 0;
+}
+
+
+
+/*
+ * call callback functions (if any):
+ * the callbacks are invoked only when the first (for connection) or
+ * the last subscription (for disconnection) is done. Second or later
+ * subscription results in increment of counter, but no callback is
+ * invoked.
+ * This feature is useful if these callbacks are associated with
+ * initialization or termination of devices (see seq_midi.c).
+ */
+
+static int subscribe_port(struct snd_seq_client *client,
+ struct snd_seq_client_port *port,
+ struct snd_seq_port_subs_info *grp,
+ struct snd_seq_port_subscribe *info,
+ int send_ack)
+{
+ int err = 0;
+
+ if (!try_module_get(port->owner))
+ return -EFAULT;
+ grp->count++;
+ if (grp->open && grp->count == 1) {
+ err = grp->open(port->private_data, info);
+ if (err < 0) {
+ module_put(port->owner);
+ grp->count--;
+ }
+ }
+ if (err >= 0 && send_ack && client->type == USER_CLIENT)
+ snd_seq_client_notify_subscription(port->addr.client, port->addr.port,
+ info, SNDRV_SEQ_EVENT_PORT_SUBSCRIBED);
+
+ return err;
+}
+
+static int unsubscribe_port(struct snd_seq_client *client,
+ struct snd_seq_client_port *port,
+ struct snd_seq_port_subs_info *grp,
+ struct snd_seq_port_subscribe *info,
+ int send_ack)
+{
+ int err = 0;
+
+ if (! grp->count)
+ return -EINVAL;
+ grp->count--;
+ if (grp->close && grp->count == 0)
+ err = grp->close(port->private_data, info);
+ if (send_ack && client->type == USER_CLIENT)
+ snd_seq_client_notify_subscription(port->addr.client, port->addr.port,
+ info, SNDRV_SEQ_EVENT_PORT_UNSUBSCRIBED);
+ module_put(port->owner);
+ return err;
+}
+
+
+
+/* check if both addresses are identical */
+static inline int addr_match(struct snd_seq_addr *r, struct snd_seq_addr *s)
+{
+ return (r->client == s->client) && (r->port == s->port);
+}
+
+/* check the two subscribe info match */
+/* if flags is zero, checks only sender and destination addresses */
+static int match_subs_info(struct snd_seq_port_subscribe *r,
+ struct snd_seq_port_subscribe *s)
+{
+ if (addr_match(&r->sender, &s->sender) &&
+ addr_match(&r->dest, &s->dest)) {
+ if (r->flags && r->flags == s->flags)
+ return r->queue == s->queue;
+ else if (! r->flags)
+ return 1;
+ }
+ return 0;
+}
+
+
+/* connect two ports */
+int snd_seq_port_connect(struct snd_seq_client *connector,
+ struct snd_seq_client *src_client,
+ struct snd_seq_client_port *src_port,
+ struct snd_seq_client *dest_client,
+ struct snd_seq_client_port *dest_port,
+ struct snd_seq_port_subscribe *info)
+{
+ struct snd_seq_port_subs_info *src = &src_port->c_src;
+ struct snd_seq_port_subs_info *dest = &dest_port->c_dest;
+ struct snd_seq_subscribers *subs, *s;
+ int err, src_called = 0;
+ unsigned long flags;
+ int exclusive;
+
+ subs = kzalloc(sizeof(*subs), GFP_KERNEL);
+ if (! subs)
+ return -ENOMEM;
+
+ subs->info = *info;
+ atomic_set(&subs->ref_count, 2);
+
+ down_write(&src->list_mutex);
+ down_write_nested(&dest->list_mutex, SINGLE_DEPTH_NESTING);
+
+ exclusive = info->flags & SNDRV_SEQ_PORT_SUBS_EXCLUSIVE ? 1 : 0;
+ err = -EBUSY;
+ if (exclusive) {
+ if (! list_empty(&src->list_head) || ! list_empty(&dest->list_head))
+ goto __error;
+ } else {
+ if (src->exclusive || dest->exclusive)
+ goto __error;
+ /* check whether already exists */
+ list_for_each_entry(s, &src->list_head, src_list) {
+ if (match_subs_info(info, &s->info))
+ goto __error;
+ }
+ list_for_each_entry(s, &dest->list_head, dest_list) {
+ if (match_subs_info(info, &s->info))
+ goto __error;
+ }
+ }
+
+ if ((err = subscribe_port(src_client, src_port, src, info,
+ connector->number != src_client->number)) < 0)
+ goto __error;
+ src_called = 1;
+
+ if ((err = subscribe_port(dest_client, dest_port, dest, info,
+ connector->number != dest_client->number)) < 0)
+ goto __error;
+
+ /* add to list */
+ write_lock_irqsave(&src->list_lock, flags);
+ // write_lock(&dest->list_lock); // no other lock yet
+ list_add_tail(&subs->src_list, &src->list_head);
+ list_add_tail(&subs->dest_list, &dest->list_head);
+ // write_unlock(&dest->list_lock); // no other lock yet
+ write_unlock_irqrestore(&src->list_lock, flags);
+
+ src->exclusive = dest->exclusive = exclusive;
+
+ up_write(&dest->list_mutex);
+ up_write(&src->list_mutex);
+ return 0;
+
+ __error:
+ if (src_called)
+ unsubscribe_port(src_client, src_port, src, info,
+ connector->number != src_client->number);
+ kfree(subs);
+ up_write(&dest->list_mutex);
+ up_write(&src->list_mutex);
+ return err;
+}
+
+
+/* remove the connection */
+int snd_seq_port_disconnect(struct snd_seq_client *connector,
+ struct snd_seq_client *src_client,
+ struct snd_seq_client_port *src_port,
+ struct snd_seq_client *dest_client,
+ struct snd_seq_client_port *dest_port,
+ struct snd_seq_port_subscribe *info)
+{
+ struct snd_seq_port_subs_info *src = &src_port->c_src;
+ struct snd_seq_port_subs_info *dest = &dest_port->c_dest;
+ struct snd_seq_subscribers *subs;
+ int err = -ENOENT;
+ unsigned long flags;
+
+ down_write(&src->list_mutex);
+ down_write_nested(&dest->list_mutex, SINGLE_DEPTH_NESTING);
+
+ /* look for the connection */
+ list_for_each_entry(subs, &src->list_head, src_list) {
+ if (match_subs_info(info, &subs->info)) {
+ write_lock_irqsave(&src->list_lock, flags);
+ // write_lock(&dest->list_lock); // no lock yet
+ list_del(&subs->src_list);
+ list_del(&subs->dest_list);
+ // write_unlock(&dest->list_lock);
+ write_unlock_irqrestore(&src->list_lock, flags);
+ src->exclusive = dest->exclusive = 0;
+ unsubscribe_port(src_client, src_port, src, info,
+ connector->number != src_client->number);
+ unsubscribe_port(dest_client, dest_port, dest, info,
+ connector->number != dest_client->number);
+ kfree(subs);
+ err = 0;
+ break;
+ }
+ }
+
+ up_write(&dest->list_mutex);
+ up_write(&src->list_mutex);
+ return err;
+}
+
+
+/* get matched subscriber */
+struct snd_seq_subscribers *snd_seq_port_get_subscription(struct snd_seq_port_subs_info *src_grp,
+ struct snd_seq_addr *dest_addr)
+{
+ struct snd_seq_subscribers *s, *found = NULL;
+
+ down_read(&src_grp->list_mutex);
+ list_for_each_entry(s, &src_grp->list_head, src_list) {
+ if (addr_match(dest_addr, &s->info.dest)) {
+ found = s;
+ break;
+ }
+ }
+ up_read(&src_grp->list_mutex);
+ return found;
+}
+
+/*
+ * Attach a device driver that wants to receive events from the
+ * sequencer. Returns the new port number on success.
+ * A driver that wants to receive the events converted to midi, will
+ * use snd_seq_midisynth_register_port().
+ */
+/* exported */
+int snd_seq_event_port_attach(int client,
+ struct snd_seq_port_callback *pcbp,
+ int cap, int type, int midi_channels,
+ int midi_voices, char *portname)
+{
+ struct snd_seq_port_info portinfo;
+ int ret;
+
+ /* Set up the port */
+ memset(&portinfo, 0, sizeof(portinfo));
+ portinfo.addr.client = client;
+ strlcpy(portinfo.name, portname ? portname : "Unamed port",
+ sizeof(portinfo.name));
+
+ portinfo.capability = cap;
+ portinfo.type = type;
+ portinfo.kernel = pcbp;
+ portinfo.midi_channels = midi_channels;
+ portinfo.midi_voices = midi_voices;
+
+ /* Create it */
+ ret = snd_seq_kernel_client_ctl(client,
+ SNDRV_SEQ_IOCTL_CREATE_PORT,
+ &portinfo);
+
+ if (ret >= 0)
+ ret = portinfo.addr.port;
+
+ return ret;
+}
+
+EXPORT_SYMBOL(snd_seq_event_port_attach);
+
+/*
+ * Detach the driver from a port.
+ */
+/* exported */
+int snd_seq_event_port_detach(int client, int port)
+{
+ struct snd_seq_port_info portinfo;
+ int err;
+
+ memset(&portinfo, 0, sizeof(portinfo));
+ portinfo.addr.client = client;
+ portinfo.addr.port = port;
+ err = snd_seq_kernel_client_ctl(client,
+ SNDRV_SEQ_IOCTL_DELETE_PORT,
+ &portinfo);
+
+ return err;
+}
+
+EXPORT_SYMBOL(snd_seq_event_port_detach);
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