Commit d827bd47 authored by Elliot Berman's avatar Elliot Berman Committed by huangdengdui
Browse files

mailbox: pcc: Use mbox_bind_client 

mainline inclusion
from mainline-v6.4-rc1
commit 76d4adac
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I9S5DK
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=76d4adacd52e78bea2e393081f2a5766261d1e3a



--------------------------------

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: default avatarSudeep Holla <sudeep.holla@arm.com>
Signed-off-by: default avatarElliot Berman <quic_eberman@quicinc.com>
Signed-off-by: default avatarJassi Brar <jaswinder.singh@linaro.org>
parent c3900f10

drivers/mailbox/pcc.c

+45 −39
Original line number Diff line number Diff line
@@ -282,8 +282,7 @@ 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);
@@ -294,32 +293,10 @@ pcc_mbox_request_channel(struct mbox_client *cl, int subspace_id) 
		pr_err("Channel not found for idx: %d\n", subspace_id);

		return ERR_PTR(-EBUSY);

	}

	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);

	rc = mbox_bind_client(chan, cl);

	if (rc)

		return ERR_PTR(rc);

		}

	}



	return &pchan->chan;

}
@@ -333,23 +310,12 @@ 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 +343,48 @@ 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.

 */

static 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.

 */

static 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,

};



/**