6.1-stable review patch. If anyone has any objections, please let me know.
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From: Elliot Berman quic_eberman@quicinc.com
[ Upstream commit 85a953806557dbf25d16e8c132b5b9b100d16496 ]
Support virtual mailbox controllers and clients which are not platform devices or come from the devicetree by allowing them to match client to channel via some other mechanism.
Tested-by: Sudeep Holla sudeep.holla@arm.com (pcc) Signed-off-by: Elliot Berman quic_eberman@quicinc.com Signed-off-by: Jassi Brar jaswinder.singh@linaro.org Stable-dep-of: ff0e4d4c97c9 ("mailbox: pcc: don't zero error register") Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/mailbox/mailbox.c | 96 ++++++++++++++++++++++++---------- include/linux/mailbox_client.h | 1 + 2 files changed, 69 insertions(+), 28 deletions(-)
diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c index cb31ad917b352..f4cfbdfe4111c 100644 --- a/drivers/mailbox/mailbox.c +++ b/drivers/mailbox/mailbox.c @@ -317,6 +317,71 @@ int mbox_flush(struct mbox_chan *chan, unsigned long timeout) } EXPORT_SYMBOL_GPL(mbox_flush);
+static int __mbox_bind_client(struct mbox_chan *chan, struct mbox_client *cl) +{ + struct device *dev = cl->dev; + unsigned long flags; + int ret; + + if (chan->cl || !try_module_get(chan->mbox->dev->driver->owner)) { + dev_dbg(dev, "%s: mailbox not free\n", __func__); + return -EBUSY; + } + + 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 (chan->mbox->ops->startup) { + ret = chan->mbox->ops->startup(chan); + + if (ret) { + dev_err(dev, "Unable to startup the chan (%d)\n", ret); + mbox_free_channel(chan); + return ret; + } + } + + return 0; +} + +/** + * mbox_bind_client - Request a mailbox channel. + * @chan: The mailbox channel to bind the client to. + * @cl: Identity of the client requesting the channel. + * + * The Client specifies its requirements and capabilities while asking for + * a mailbox channel. It can't be called from atomic context. + * The channel is exclusively allocated and can't be used by another + * client before the owner calls mbox_free_channel. + * After assignment, any packet received on this channel will be + * handed over to the client via the 'rx_callback'. + * The framework holds reference to the client, so the mbox_client + * structure shouldn't be modified until the mbox_free_channel returns. + * + * Return: 0 if the channel was assigned to the client successfully. + * <0 for request failure. + */ +int mbox_bind_client(struct mbox_chan *chan, struct mbox_client *cl) +{ + int ret; + + mutex_lock(&con_mutex); + ret = __mbox_bind_client(chan, cl); + mutex_unlock(&con_mutex); + + return ret; +} +EXPORT_SYMBOL_GPL(mbox_bind_client); + /** * mbox_request_channel - Request a mailbox channel. * @cl: Identity of the client requesting the channel. @@ -340,7 +405,6 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index) struct mbox_controller *mbox; struct of_phandle_args spec; struct mbox_chan *chan; - unsigned long flags; int ret;
if (!dev || !dev->of_node) { @@ -373,33 +437,9 @@ struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index) return chan; }
- if (chan->cl || !try_module_get(mbox->dev->driver->owner)) { - dev_dbg(dev, "%s: mailbox not free\n", __func__); - mutex_unlock(&con_mutex); - return ERR_PTR(-EBUSY); - } - - 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 (chan->mbox->ops->startup) { - ret = chan->mbox->ops->startup(chan); - - if (ret) { - dev_err(dev, "Unable to startup the chan (%d)\n", ret); - mbox_free_channel(chan); - chan = ERR_PTR(ret); - } - } + ret = __mbox_bind_client(chan, cl); + if (ret) + chan = ERR_PTR(ret);
mutex_unlock(&con_mutex); return chan; diff --git a/include/linux/mailbox_client.h b/include/linux/mailbox_client.h index 65229a45590f1..734694912ef74 100644 --- a/include/linux/mailbox_client.h +++ b/include/linux/mailbox_client.h @@ -37,6 +37,7 @@ struct mbox_client { void (*tx_done)(struct mbox_client *cl, void *mssg, int r); };
+int mbox_bind_client(struct mbox_chan *chan, struct mbox_client *cl); struct mbox_chan *mbox_request_channel_byname(struct mbox_client *cl, const char *name); struct mbox_chan *mbox_request_channel(struct mbox_client *cl, int index);