mailbox: pcc: Use PCC mailbox channel pointer instead of standard

Now that we have all the shared memory region information populated in
the pcc_mbox_chan, let us propagate the pointer to the same as the
return value to pcc_mbox_request channel.

This eliminates the need for the individual users of PCC mailbox to
parse the PCCT subspace entries and fetch the shmem information. This
also eliminates the need for PCC mailbox controller to set con_priv to
PCCT subspace entries. This is required as con_priv is private to the
controller driver to attach private data associated with the channel and
not meant to be used by the mailbox client/users.

Let us convert all the users of pcc_mbox_{request,free}_channel to use
new interface.

Cc: Jean Delvare <jdelvare@suse.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Wolfram Sang <wsa@kernel.org>
Acked-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>

1 files changed, 18 insertions, 45 deletions

diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index f358ced827f2..453a58fda3a4 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c
@@ -79,24 +79,9 @@ struct pcc_chan_info {
 	int db_irq;
 };
 
+#define to_pcc_chan_info(c) container_of(c, struct pcc_chan_info, chan)
 static struct pcc_chan_info *chan_info;
-
 static struct mbox_controller pcc_mbox_ctrl = {};
-/**
- * get_pcc_channel - Given a PCC subspace idx, get
- *	the respective mbox_channel.
- * @id: PCC subspace index.
- *
- * Return: ERR_PTR(errno) if error, else pointer
- *	to mbox channel.
- */
-static struct mbox_chan *get_pcc_channel(int id)
-{
-	if (id < 0 || id >= pcc_mbox_ctrl.num_chans)
-		return ERR_PTR(-ENOENT);
-
-	return &pcc_mbox_channels[id];
-}
 
 /*
  * PCC can be used with perf critical drivers such as CPPC
@@ -239,31 +224,25 @@ static irqreturn_t pcc_mbox_irq(int irq, void *p)
  *		ACPI package. This is used to lookup the array of PCC
  *		subspaces as parsed by the PCC Mailbox controller.
  *
- * Return: Pointer to the Mailbox Channel if successful or
- *		ERR_PTR.
+ * Return: Pointer to the PCC Mailbox Channel if successful or ERR_PTR.
  */
-struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
-					   int subspace_id)
+struct pcc_mbox_chan *
+pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id)
 {
 	struct pcc_chan_info *pchan;
 	struct device *dev = pcc_mbox_ctrl.dev;
 	struct mbox_chan *chan;
 	unsigned long flags;
 
-	/*
-	 * Each PCC Subspace is a Mailbox Channel.
-	 * The PCC Clients get their PCC Subspace ID
-	 * from their own tables and pass it here.
-	 * This returns a pointer to the PCC subspace
-	 * for the Client to operate on.
-	 */
-	chan = get_pcc_channel(subspace_id);
+	if (subspace_id < 0 || subspace_id >= pcc_mbox_ctrl.num_chans)
+		return ERR_PTR(-ENOENT);
 
+	pchan = chan_info + subspace_id;
+	chan = pchan->chan.mchan;
 	if (IS_ERR(chan) || chan->cl) {
 		dev_err(dev, "Channel not found for idx: %d\n", subspace_id);
 		return ERR_PTR(-EBUSY);
 	}
-	pchan = chan_info + subspace_id;
 
 	spin_lock_irqsave(&chan->lock, flags);
 	chan->msg_free = 0;
@@ -285,38 +264,32 @@ struct mbox_chan *pcc_mbox_request_channel(struct mbox_client *cl,
 		if (unlikely(rc)) {
 			dev_err(dev, "failed to register PCC interrupt %d\n",
 				pchan->db_irq);
-			pcc_mbox_free_channel(chan);
-			chan = ERR_PTR(rc);
+			pcc_mbox_free_channel(&pchan->chan);
+			return ERR_PTR(rc);
 		}
 	}
 
-	return chan;
+	return &pchan->chan;
 }
 EXPORT_SYMBOL_GPL(pcc_mbox_request_channel);
 
 /**
  * pcc_mbox_free_channel - Clients call this to free their Channel.
  *
- * @chan: Pointer to the mailbox channel as returned by
- *		pcc_mbox_request_channel()
+ * @pchan: Pointer to the PCC mailbox channel as returned by
+ *	   pcc_mbox_request_channel()
  */
-void pcc_mbox_free_channel(struct mbox_chan *chan)
+void pcc_mbox_free_channel(struct pcc_mbox_chan *pchan)
 {
-	u32 id = chan - pcc_mbox_channels;
-	struct pcc_chan_info *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 (id >= pcc_mbox_ctrl.num_chans) {
-		pr_debug("pcc_mbox_free_channel: Invalid mbox_chan passed\n");
-		return;
-	}
-
-	pchan = chan_info + id;
-	if (pchan->db_irq > 0)
-		devm_free_irq(chan->mbox->dev, pchan->db_irq, chan);
+	if (pchan_info->db_irq > 0)
+		devm_free_irq(chan->mbox->dev, pchan_info->db_irq, chan);
 
 	spin_lock_irqsave(&chan->lock, flags);
 	chan->cl = NULL;