From 863981e96738983919de841ec669e157e6bdaeb0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Sun, 11 Sep 2016 04:34:46 -0300 Subject: Linux-libre 4.7.1-gnu --- drivers/soc/qcom/smd.c | 247 +++++++++++++++++++++++++++++++++++++------------ 1 file changed, 188 insertions(+), 59 deletions(-) (limited to 'drivers/soc/qcom/smd.c') diff --git a/drivers/soc/qcom/smd.c b/drivers/soc/qcom/smd.c index 498fd0581..ac1957dfd 100644 --- a/drivers/soc/qcom/smd.c +++ b/drivers/soc/qcom/smd.c @@ -106,9 +106,9 @@ static const struct { * @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; @@ -127,10 +127,12 @@ struct qcom_smd_edge { 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; }; /* @@ -186,13 +188,16 @@ struct qcom_smd_channel { 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; + void *drvdata; + struct list_head list; + struct list_head dev_list; }; /** @@ -377,6 +382,19 @@ static void qcom_smd_channel_reset(struct qcom_smd_channel *channel) 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 */ @@ -497,7 +515,6 @@ static void qcom_smd_channel_advance(struct qcom_smd_channel *channel, */ static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel) { - struct qcom_smd_device *qsdev = channel->qsdev; unsigned tail; size_t len; void *ptr; @@ -517,7 +534,7 @@ static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel) len = channel->pkt_size; } - ret = channel->cb(qsdev, ptr, len); + ret = channel->cb(channel, ptr, len); if (ret < 0) return ret; @@ -601,7 +618,8 @@ static irqreturn_t qcom_smd_edge_intr(int irq, void *data) struct qcom_smd_edge *edge = data; struct qcom_smd_channel *channel; unsigned available; - bool kick_worker = false; + bool kick_scanner = false; + bool kick_state = false; /* * Handle state changes or data on each of the channels on this edge @@ -609,7 +627,7 @@ static irqreturn_t qcom_smd_edge_intr(int irq, void *data) spin_lock(&edge->channels_lock); list_for_each_entry(channel, &edge->channels, list) { spin_lock(&channel->recv_lock); - kick_worker |= qcom_smd_channel_intr(channel); + kick_state |= qcom_smd_channel_intr(channel); spin_unlock(&channel->recv_lock); } spin_unlock(&edge->channels_lock); @@ -622,12 +640,13 @@ static irqreturn_t qcom_smd_edge_intr(int irq, void *data) 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; + kick_scanner = true; } - if (kick_worker) - schedule_work(&edge->work); + if (kick_scanner) + schedule_work(&edge->scan_work); + if (kick_state) + schedule_work(&edge->state_work); return IRQ_HANDLED; } @@ -793,18 +812,12 @@ static int qcom_smd_dev_match(struct device *dev, struct device_driver *drv) } /* - * 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 @@ -814,12 +827,44 @@ static int qcom_smd_dev_probe(struct device *dev) 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; @@ -831,11 +876,7 @@ static int qcom_smd_dev_probe(struct device *dev) 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; } @@ -850,16 +891,15 @@ static int qcom_smd_dev_remove(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; - 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); @@ -872,15 +912,14 @@ static int qcom_smd_dev_remove(struct device *dev) 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; } @@ -996,6 +1035,18 @@ int qcom_smd_driver_register(struct qcom_smd_driver *qsdrv) } EXPORT_SYMBOL(qcom_smd_driver_register); +void *qcom_smd_get_drvdata(struct qcom_smd_channel *channel) +{ + return channel->drvdata; +} +EXPORT_SYMBOL(qcom_smd_get_drvdata); + +void qcom_smd_set_drvdata(struct qcom_smd_channel *channel, void *data) +{ + channel->drvdata = data; +} +EXPORT_SYMBOL(qcom_smd_set_drvdata); + /** * qcom_smd_driver_unregister - unregister a smd driver * @qsdrv: qcom_smd_driver struct @@ -1006,6 +1057,78 @@ void qcom_smd_driver_unregister(struct qcom_smd_driver *qsdrv) } 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 long flags; + unsigned state; + + spin_lock_irqsave(&edge->channels_lock, flags); + 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; + } + spin_unlock_irqrestore(&edge->channels_lock, flags); + + 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_channel *parent, + const char *name, + qcom_smd_cb_t cb) +{ + struct qcom_smd_channel *channel; + struct qcom_smd_device *sdev = parent->qsdev; + struct qcom_smd_edge *edge = parent->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. @@ -1027,6 +1150,7 @@ static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *ed 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) @@ -1089,8 +1213,9 @@ free_name_and_channel: * 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; @@ -1140,10 +1265,12 @@ static void qcom_discover_channels(struct qcom_smd_edge *edge) 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); } /* @@ -1151,29 +1278,23 @@ static void qcom_discover_channels(struct qcom_smd_edge *edge) * 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); - } + unsigned long flags; /* * Register a device for any closed channel where the remote processor * is showing interest in opening the channel. */ + spin_lock_irqsave(&edge->channels_lock, flags); list_for_each_entry(channel, &edge->channels, list) { if (channel->state != SMD_CHANNEL_CLOSED) continue; @@ -1183,7 +1304,9 @@ static void qcom_channel_state_worker(struct work_struct *work) remote_state != SMD_CHANNEL_OPENED) continue; + spin_unlock_irqrestore(&edge->channels_lock, flags); qcom_smd_create_device(channel); + spin_lock_irqsave(&edge->channels_lock, flags); } /* @@ -1200,8 +1323,11 @@ static void qcom_channel_state_worker(struct work_struct *work) remote_state == SMD_CHANNEL_OPENED) continue; + spin_unlock_irqrestore(&edge->channels_lock, flags); qcom_smd_destroy_device(channel); + spin_lock_irqsave(&edge->channels_lock, flags); } + spin_unlock_irqrestore(&edge->channels_lock, flags); } /* @@ -1219,7 +1345,8 @@ static int qcom_smd_parse_edge(struct device *dev, INIT_LIST_HEAD(&edge->channels); spin_lock_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); @@ -1303,13 +1430,13 @@ static int qcom_smd_probe(struct platform_device *pdev) 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); @@ -1332,8 +1459,10 @@ static int qcom_smd_remove(struct platform_device *pdev) 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; -- cgit v1.2.3-54-g00ecf