* @channels: list of all channels detected on this edge
* @channels_lock: guard for modifications of @channels
* @allocated: array of bitmaps representing already allocated channels
- * @need_rescan: flag that the @work needs to scan smem for new channels
* @smem_available: last available amount of smem triggering a channel scan
- * @work: work item for edge house keeping
+ * @scan_work: work item for discovering new channels
+ * @state_work: work item for edge state changes
*/
struct qcom_smd_edge {
struct qcom_smd *smd;
int ipc_bit;
struct list_head channels;
- spinlock_t channels_lock;
+ rwlock_t channels_lock;
DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE);
- bool need_rescan;
unsigned smem_available;
- struct work_struct work;
+ wait_queue_head_t new_channel_event;
+
+ struct work_struct scan_work;
+ struct work_struct state_work;
};
/*
int fifo_size;
void *bounce_buffer;
- int (*cb)(struct qcom_smd_device *, const void *, size_t);
+ qcom_smd_cb_t cb;
spinlock_t recv_lock;
int pkt_size;
struct list_head list;
+ struct list_head dev_list;
};
/**
channel->pkt_size = 0;
}
+/*
+ * Set the callback for a channel, with appropriate locking
+ */
+static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel,
+ qcom_smd_cb_t cb)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&channel->recv_lock, flags);
+ channel->cb = cb;
+ spin_unlock_irqrestore(&channel->recv_lock, flags);
+};
+
/*
* Calculate the amount of data available in the rx fifo
*/
/*
* Handle state changes or data on each of the channels on this edge
*/
- spin_lock(&edge->channels_lock);
+ read_lock(&edge->channels_lock);
list_for_each_entry(channel, &edge->channels, list) {
spin_lock(&channel->recv_lock);
kick_worker |= qcom_smd_channel_intr(channel);
spin_unlock(&channel->recv_lock);
}
- spin_unlock(&edge->channels_lock);
+ read_unlock(&edge->channels_lock);
/*
* Creating a new channel requires allocating an smem entry, so we only
available = qcom_smem_get_free_space(edge->remote_pid);
if (available != edge->smem_available) {
edge->smem_available = available;
- edge->need_rescan = true;
kick_worker = true;
}
if (kick_worker)
- schedule_work(&edge->work);
+ schedule_work(&edge->scan_work);
return IRQ_HANDLED;
}
}
/*
- * Probe the smd client.
- *
- * The remote side have indicated that it want the channel to be opened, so
- * complete the state handshake and probe our client driver.
+ * Helper for opening a channel
*/
-static int qcom_smd_dev_probe(struct device *dev)
+static int qcom_smd_channel_open(struct qcom_smd_channel *channel,
+ qcom_smd_cb_t cb)
{
- struct qcom_smd_device *qsdev = to_smd_device(dev);
- struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
- struct qcom_smd_channel *channel = qsdev->channel;
size_t bb_size;
- int ret;
/*
* Packets are maximum 4k, but reduce if the fifo is smaller
if (!channel->bounce_buffer)
return -ENOMEM;
- channel->cb = qsdrv->callback;
-
+ qcom_smd_channel_set_callback(channel, cb);
qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING);
-
qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED);
+ return 0;
+}
+
+/*
+ * Helper for closing and resetting a channel
+ */
+static void qcom_smd_channel_close(struct qcom_smd_channel *channel)
+{
+ qcom_smd_channel_set_callback(channel, NULL);
+
+ kfree(channel->bounce_buffer);
+ channel->bounce_buffer = NULL;
+
+ qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
+ qcom_smd_channel_reset(channel);
+}
+
+/*
+ * Probe the smd client.
+ *
+ * The remote side have indicated that it want the channel to be opened, so
+ * complete the state handshake and probe our client driver.
+ */
+static int qcom_smd_dev_probe(struct device *dev)
+{
+ struct qcom_smd_device *qsdev = to_smd_device(dev);
+ struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
+ struct qcom_smd_channel *channel = qsdev->channel;
+ int ret;
+
+ ret = qcom_smd_channel_open(channel, qsdrv->callback);
+ if (ret)
+ return ret;
+
ret = qsdrv->probe(qsdev);
if (ret)
goto err;
err:
dev_err(&qsdev->dev, "probe failed\n");
- channel->cb = NULL;
- kfree(channel->bounce_buffer);
- channel->bounce_buffer = NULL;
-
- qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
+ qcom_smd_channel_close(channel);
return ret;
}
struct qcom_smd_device *qsdev = to_smd_device(dev);
struct qcom_smd_driver *qsdrv = to_smd_driver(dev);
struct qcom_smd_channel *channel = qsdev->channel;
- unsigned long flags;
+ struct qcom_smd_channel *tmp;
+ struct qcom_smd_channel *ch;
qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSING);
/*
* Make sure we don't race with the code receiving data.
*/
- spin_lock_irqsave(&channel->recv_lock, flags);
- channel->cb = NULL;
- spin_unlock_irqrestore(&channel->recv_lock, flags);
+ qcom_smd_channel_set_callback(channel, NULL);
/* Wake up any sleepers in qcom_smd_send() */
wake_up_interruptible(&channel->fblockread_event);
qsdrv->remove(qsdev);
/*
- * The client is now gone, cleanup and reset the channel state.
+ * The client is now gone, close and release all channels associated
+ * with this sdev
*/
- channel->qsdev = NULL;
- kfree(channel->bounce_buffer);
- channel->bounce_buffer = NULL;
-
- qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED);
-
- qcom_smd_channel_reset(channel);
+ list_for_each_entry_safe(ch, tmp, &channel->dev_list, dev_list) {
+ qcom_smd_channel_close(ch);
+ list_del(&ch->dev_list);
+ ch->qsdev = NULL;
+ }
return 0;
}
}
EXPORT_SYMBOL(qcom_smd_driver_unregister);
+static struct qcom_smd_channel *
+qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name)
+{
+ struct qcom_smd_channel *channel;
+ struct qcom_smd_channel *ret = NULL;
+ unsigned state;
+
+ read_lock(&edge->channels_lock);
+ list_for_each_entry(channel, &edge->channels, list) {
+ if (strcmp(channel->name, name))
+ continue;
+
+ state = GET_RX_CHANNEL_INFO(channel, state);
+ if (state != SMD_CHANNEL_OPENING &&
+ state != SMD_CHANNEL_OPENED)
+ continue;
+
+ ret = channel;
+ break;
+ }
+ read_unlock(&edge->channels_lock);
+
+ return ret;
+}
+
+/**
+ * qcom_smd_open_channel() - claim additional channels on the same edge
+ * @sdev: smd_device handle
+ * @name: channel name
+ * @cb: callback method to use for incoming data
+ *
+ * Returns a channel handle on success, or -EPROBE_DEFER if the channel isn't
+ * ready.
+ */
+struct qcom_smd_channel *qcom_smd_open_channel(struct qcom_smd_device *sdev,
+ const char *name,
+ qcom_smd_cb_t cb)
+{
+ struct qcom_smd_channel *channel;
+ struct qcom_smd_edge *edge = sdev->channel->edge;
+ int ret;
+
+ /* Wait up to HZ for the channel to appear */
+ ret = wait_event_interruptible_timeout(edge->new_channel_event,
+ (channel = qcom_smd_find_channel(edge, name)) != NULL,
+ HZ);
+ if (!ret)
+ return ERR_PTR(-ETIMEDOUT);
+
+ if (channel->state != SMD_CHANNEL_CLOSED) {
+ dev_err(&sdev->dev, "channel %s is busy\n", channel->name);
+ return ERR_PTR(-EBUSY);
+ }
+
+ channel->qsdev = sdev;
+ ret = qcom_smd_channel_open(channel, cb);
+ if (ret) {
+ channel->qsdev = NULL;
+ return ERR_PTR(ret);
+ }
+
+ /*
+ * Append the list of channel to the channels associated with the sdev
+ */
+ list_add_tail(&channel->dev_list, &sdev->channel->dev_list);
+
+ return channel;
+}
+EXPORT_SYMBOL(qcom_smd_open_channel);
+
/*
* Allocate the qcom_smd_channel object for a newly found smd channel,
* retrieving and validating the smem items involved.
if (!channel)
return ERR_PTR(-ENOMEM);
+ INIT_LIST_HEAD(&channel->dev_list);
channel->edge = edge;
channel->name = devm_kstrdup(smd->dev, name, GFP_KERNEL);
if (!channel->name)
* qcom_smd_create_channel() to create representations of these and add
* them to the edge's list of channels.
*/
-static void qcom_discover_channels(struct qcom_smd_edge *edge)
+static void qcom_channel_scan_worker(struct work_struct *work)
{
+ struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work);
struct qcom_smd_alloc_entry *alloc_tbl;
struct qcom_smd_alloc_entry *entry;
struct qcom_smd_channel *channel;
if (IS_ERR(channel))
continue;
- spin_lock_irqsave(&edge->channels_lock, flags);
+ write_lock_irqsave(&edge->channels_lock, flags);
list_add(&channel->list, &edge->channels);
- spin_unlock_irqrestore(&edge->channels_lock, flags);
+ write_unlock_irqrestore(&edge->channels_lock, flags);
dev_dbg(smd->dev, "new channel found: '%s'\n", channel->name);
set_bit(i, edge->allocated[tbl]);
+
+ wake_up_interruptible(&edge->new_channel_event);
}
}
- schedule_work(&edge->work);
+ schedule_work(&edge->state_work);
}
/*
* then scans all registered channels for state changes that should be handled
* by creating or destroying smd client devices for the registered channels.
*
- * LOCKING: edge->channels_lock is not needed to be held during the traversal
- * of the channels list as it's done synchronously with the only writer.
+ * LOCKING: edge->channels_lock only needs to cover the list operations, as the
+ * worker is killed before any channels are deallocated
*/
static void qcom_channel_state_worker(struct work_struct *work)
{
struct qcom_smd_channel *channel;
struct qcom_smd_edge *edge = container_of(work,
struct qcom_smd_edge,
- work);
+ state_work);
unsigned remote_state;
- /*
- * Rescan smem if we have reason to belive that there are new channels.
- */
- if (edge->need_rescan) {
- edge->need_rescan = false;
- qcom_discover_channels(edge);
- }
-
/*
* Register a device for any closed channel where the remote processor
* is showing interest in opening the channel.
*/
+ read_lock(&edge->channels_lock);
list_for_each_entry(channel, &edge->channels, list) {
if (channel->state != SMD_CHANNEL_CLOSED)
continue;
remote_state != SMD_CHANNEL_OPENED)
continue;
+ read_unlock(&edge->channels_lock);
qcom_smd_create_device(channel);
+ read_lock(&edge->channels_lock);
}
/*
remote_state == SMD_CHANNEL_OPENED)
continue;
+ read_unlock(&edge->channels_lock);
qcom_smd_destroy_device(channel);
+ read_lock(&edge->channels_lock);
}
+ read_unlock(&edge->channels_lock);
}
/*
int ret;
INIT_LIST_HEAD(&edge->channels);
- spin_lock_init(&edge->channels_lock);
+ rwlock_init(&edge->channels_lock);
- INIT_WORK(&edge->work, qcom_channel_state_worker);
+ INIT_WORK(&edge->scan_work, qcom_channel_scan_worker);
+ INIT_WORK(&edge->state_work, qcom_channel_state_worker);
edge->of_node = of_node_get(node);
for_each_available_child_of_node(pdev->dev.of_node, node) {
edge = &smd->edges[i++];
edge->smd = smd;
+ init_waitqueue_head(&edge->new_channel_event);
ret = qcom_smd_parse_edge(&pdev->dev, node, edge);
if (ret)
continue;
- edge->need_rescan = true;
- schedule_work(&edge->work);
+ schedule_work(&edge->scan_work);
}
platform_set_drvdata(pdev, smd);
edge = &smd->edges[i];
disable_irq(edge->irq);
- cancel_work_sync(&edge->work);
+ cancel_work_sync(&edge->scan_work);
+ cancel_work_sync(&edge->state_work);
+ /* No need to lock here, because the writer is gone */
list_for_each_entry(channel, &edge->channels, list) {
if (!channel->qsdev)
continue;
projects / karo-tx-linux.git / blobdiff