Currently, the message send queue size in Linux mailbox framework
is hard-coded to MBOX_TX_QUEUE_LEN which is defined as 20.
This message send queue can easily overflow if mbox_send_message()
is called for same mailbox channel several times. The size of message
send queue should not be hard-coded in Linux mailbox framework and
instead mailbox controller driver should have a mechanism to specify
message send queue size for each mailbox channel.
This patch makes message send queue size dynamic in Linux mailbox
framework and provides a mechanism to set message send queue size
for each mailbox channel. If mailbox controller driver does not set
message send queue size then we assume the hard-coded value of 20.
Signed-off-by: Anup Patel <anup.patel@xxxxxxxxxxxx>
Reviewed-by: Jonathan Richardson <jonathan.richardson@xxxxxxxxxxxx>
Reviewed-by: Scott Branden <scott.branden@xxxxxxxxxxxx>
---
drivers/mailbox/mailbox.c | 15 ++++++++++++---
include/linux/mailbox_controller.h | 5 +++--
2 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 537f4f6..ccc2aea 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -34,7 +34,7 @@ static int add_to_rbuf(struct mbox_chan *chan, void *mssg)
spin_lock_irqsave(&chan->lock, flags);
/* See if there is any space left */
- if (chan->msg_count == MBOX_TX_QUEUE_LEN) {
+ if (chan->msg_count == chan->msg_queue_len) {
spin_unlock_irqrestore(&chan->lock, flags);
return -ENOBUFS;
}
@@ -43,7 +43,7 @@ static int add_to_rbuf(struct mbox_chan *chan, void *mssg)
chan->msg_data[idx] = mssg;
chan->msg_count++;
- if (idx == MBOX_TX_QUEUE_LEN - 1)
+ if (idx == chan->msg_queue_len - 1)
chan->msg_free = 0;
else
chan->msg_free++;
@@ -70,7 +70,7 @@ static void msg_submit(struct mbox_chan *chan)
if (idx >= count)
idx -= count;
else
- idx += MBOX_TX_QUEUE_LEN - count;
+ idx += chan->msg_queue_len - count;
data = chan->msg_data[idx];
@@ -346,6 +346,12 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index)
spin_lock_irqsave(&chan->lock, flags);
chan->msg_free = 0;
chan->msg_count = 0;
+ chan->msg_data = kcalloc(chan->msg_queue_len,
+ sizeof(void *), GFP_ATOMIC);
+ if (!chan->msg_data) {
+ spin_unlock_irqrestore(&chan->lock, flags);
+ return ERR_PTR(-ENOMEM);
+ }
chan->active_req = NULL;
chan->cl = cl;
init_completion(&chan->tx_complete);
@@ -420,6 +426,7 @@ void mbox_free_channel(struct mbox_chan *chan)
chan->active_req = NULL;
if (chan->txdone_method == (TXDONE_BY_POLL | TXDONE_BY_ACK))
chan->txdone_method = TXDONE_BY_POLL;
+ kfree(chan->msg_data);
module_put(chan->mbox->dev->driver->owner);
spin_unlock_irqrestore(&chan->lock, flags);
@@ -477,6 +484,8 @@ int mbox_controller_register(struct mbox_controller *mbox)
chan->cl = NULL;
chan->mbox = mbox;
chan->txdone_method = txdone;
+ if (chan->msg_queue_len < MBOX_TX_QUEUE_LEN)
+ chan->msg_queue_len = MBOX_TX_QUEUE_LEN;
spin_lock_init(&chan->lock);
}
diff --git a/include/linux/mailbox_controller.h b/include/linux/mailbox_controller.h
index 74deadb..eba3fed 100644
--- a/include/linux/mailbox_controller.h
+++ b/include/linux/mailbox_controller.h
@@ -110,6 +110,7 @@ struct mbox_controller {
* @active_req: Currently active request hook
* @msg_count: No. of mssg currently queued
* @msg_free: Index of next available mssg slot
+ * @msg_queue_len: Max number of mssg which can be queued
* @msg_data: Hook for data packet
* @lock: Serialise access to the channel
* @con_priv: Hook for controller driver to attach private data
@@ -120,8 +121,8 @@ struct mbox_chan {
struct mbox_client *cl;
struct completion tx_complete;
void *active_req;
- unsigned msg_count, msg_free;
- void *msg_data[MBOX_TX_QUEUE_LEN];
+ unsigned int msg_count, msg_free, msg_queue_len;
+ void **msg_data;
spinlock_t lock; /* Serialise access to the channel */
void *con_priv;
};
--
2.7.4
--
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