[PATCH v2 3/3] mailbox: pcc: Use mbox_bind_client

Elliot Berman
2023-03-23T19:16:17Z

Use generic mbox_bind_client() to bind omap mailbox channel to a client.

mbox_bind_client is identical to the replaced lines, except that it:
- Does the operation under con_mutex which prevents possible races in
removal path
- Sets TXDONE_BY_ACK if pcc uses TXDONE_BY_POLL and the client knows
when tx is done. TXDONE_BY_ACK is already set if there's no interrupt,
so this is not applicable.
- Calls chan->mbox->ops->startup. This is usecase for requesting irq:
move the devm_request_irq into the startup callback and unregister it
in the shutdown path.

Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
---
drivers/mailbox/pcc.c | 82 ++++++++++++++++++++++++-------------------
1 file changed, 45 insertions(+), 37 deletions(-)

diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index 105d46c9801b..3a025415c5d5 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c
@@ -283,7 +283,7 @@ pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id)
struct pcc_chan_info *pchan;
struct mbox_chan *chan;
struct device *dev;
- unsigned long flags;
+ int rc;

if (subspace_id < 0 || subspace_id >= pcc_chan_count)
return ERR_PTR(-ENOENT);
@@ -296,30 +296,9 @@ pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id)
}
dev = chan->mbox->dev;

- spin_lock_irqsave(&chan->lock, flags);
- chan->msg_free = 0;
- chan->msg_count = 0;
- chan->active_req = NULL;
- chan->cl = cl;
- init_completion(&chan->tx_complete);
-
- if (chan->txdone_method == TXDONE_BY_POLL && cl->knows_txdone)
- chan->txdone_method = TXDONE_BY_ACK;
-
- spin_unlock_irqrestore(&chan->lock, flags);
-
- if (pchan->plat_irq > 0) {
- int rc;
-
- rc = devm_request_irq(dev, pchan->plat_irq, pcc_mbox_irq, 0,
- MBOX_IRQ_NAME, chan);
- if (unlikely(rc)) {
- dev_err(dev, "failed to register PCC interrupt %d\n",
- pchan->plat_irq);
- pcc_mbox_free_channel(&pchan->chan);
- return ERR_PTR(rc);
- }
- }
+ rc = mbox_bind_client(chan, cl);
+ if (rc)
+ return ERR_PTR(rc);

return &pchan->chan;
}
@@ -333,23 +312,12 @@ EXPORT_SYMBOL_GPL(pcc_mbox_request_channel);
*/
void pcc_mbox_free_channel(struct pcc_mbox_chan *pchan)
{
- struct pcc_chan_info *pchan_info = to_pcc_chan_info(pchan);
struct mbox_chan *chan = pchan->mchan;
- unsigned long flags;

if (!chan || !chan->cl)
return;

- if (pchan_info->plat_irq > 0)
- devm_free_irq(chan->mbox->dev, pchan_info->plat_irq, chan);
-
- spin_lock_irqsave(&chan->lock, flags);
- chan->cl = NULL;
- chan->active_req = NULL;
- if (chan->txdone_method == TXDONE_BY_ACK)
- chan->txdone_method = TXDONE_BY_POLL;
-
- spin_unlock_irqrestore(&chan->lock, flags);
+ mbox_free_channel(chan);
}
EXPORT_SYMBOL_GPL(pcc_mbox_free_channel);

@@ -377,8 +345,48 @@ static int pcc_send_data(struct mbox_chan *chan, void *data)
return pcc_chan_reg_read_modify_write(&pchan->db);
}

+/**
+ * pcc_startup - Called from Mailbox Controller code. Used here
+ * to request the interrupt.
+ * @chan: Pointer to Mailbox channel to startup.
+ *
+ * Return: Err if something failed else 0 for success.
+ */
+int pcc_startup(struct mbox_chan *chan)
+{
+ struct pcc_chan_info *pchan = chan->con_priv;
+ int rc;
+
+ if (pchan->plat_irq > 0) {
+ rc = devm_request_irq(chan->mbox->dev, pchan->plat_irq, pcc_mbox_irq, 0,
+ MBOX_IRQ_NAME, chan);
+ if (unlikely(rc)) {
+ dev_err(chan->mbox->dev, "failed to register PCC interrupt %d\n",
+ pchan->plat_irq);
+ return rc;
+ }
+ }
+
+ return 0;
+}
+
+/**
+ * pcc_shutdown - Called from Mailbox Controller code. Used here
+ * to free the interrupt.
+ * @chan: Pointer to Mailbox channel to shutdown.
+ */
+void pcc_shutdown(struct mbox_chan *chan)
+{
+ struct pcc_chan_info *pchan = chan->con_priv;
+
+ if (pchan->plat_irq > 0)
+ devm_free_irq(chan->mbox->dev, pchan->plat_irq, chan);
+}
+
static const struct mbox_chan_ops pcc_chan_ops = {
.send_data = pcc_send_data,
+ .startup = pcc_startup,
+ .shutdown = pcc_shutdown,
};

/**
--
2.39.2