diff options
Diffstat (limited to 'drivers/soc')
| -rw-r--r-- | drivers/soc/qcom/smd.c | 58 |
1 files changed, 31 insertions, 27 deletions
diff --git a/drivers/soc/qcom/smd.c b/drivers/soc/qcom/smd.c index c357842..e8972dd 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 +127,10 @@ 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; + struct work_struct scan_work; + struct work_struct state_work; }; /* @@ -614,7 +614,8 @@ 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 @@ -622,7 +623,7 @@ 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); @@ -635,12 +636,13 @@ 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; } @@ -1098,8 +1100,9 @@ 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; @@ -1152,7 +1155,7 @@ static void qcom_discover_channels(struct qcom_smd_edge *edge) } } - schedule_work(&edge->work); + schedule_work(&edge->state_work); } /* @@ -1160,29 +1163,23 @@ 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; @@ -1192,7 +1189,9 @@ 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); } /* @@ -1209,8 +1208,11 @@ 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); } /* @@ -1228,7 +1230,8 @@ 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); @@ -1317,8 +1320,7 @@ static int qcom_smd_probe(struct platform_device *pdev) if (ret) continue; - edge->need_rescan = true; - schedule_work(&edge->work); + schedule_work(&edge->scan_work); } platform_set_drvdata(pdev, smd); @@ -1341,8 +1343,10 @@ 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; |
