Commit c92c3e38 authored by Igor Skalkin's avatar Igor Skalkin Committed by Sudeep Holla
Browse files

firmware: arm_scmi: Add method to override max message number 

The maximum number of simultaneously pending messages is a transport
specific quantity that is usually described statically in struct scmi_desc.

Some transports, though, can calculate such number only at run-time after
some initial transport specific setup and probing is completed; moreover
the resulting max message numbers could also be different between rx and
tx channels.

Add an optional get_max_msg() operation so that a transport can report more
accurate max message numbers for each channel type.

The value in scmi_desc.max_msg is still used as default when transport does
not provide any get_max_msg() method.

Link: https://lore.kernel.org/r/20210803131024.40280-11-cristian.marussi@arm.com


Co-developed-by: default avatarPeter Hilber <peter.hilber@opensynergy.com>
Co-developed-by: default avatarCristian Marussi <cristian.marussi@arm.com>
Signed-off-by: default avatarIgor Skalkin <igor.skalkin@opensynergy.com>
[ Peter: Adapted patch for submission to upstream. ]
Signed-off-by: default avatarPeter Hilber <peter.hilber@opensynergy.com>
[ Cristian: refactored how get_max_msg() is used to minimize core changes ]
Signed-off-by: default avatarCristian Marussi <cristian.marussi@arm.com>
Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent a7b1138b

drivers/firmware/arm_scmi/common.h

+7 −2
Original line number Diff line number Diff line
@@ -351,6 +351,9 @@ struct scmi_chan_info { 
 * @chan_available: Callback to check if channel is available or not

 * @chan_setup: Callback to allocate and setup a channel

 * @chan_free: Callback to free a channel

 * @get_max_msg: Optional callback to provide max_msg dynamically

 *		 Returns the maximum number of messages for the channel type

 *		 (tx or rx) that can be pending simultaneously in the system

 * @send_message: Callback to send a message

 * @mark_txdone: Callback to mark tx as done

 * @fetch_response: Callback to fetch response
@@ -363,6 +366,7 @@ struct scmi_transport_ops { 
	int (*chan_setup)(struct scmi_chan_info *cinfo, struct device *dev,

			  bool tx);

	int (*chan_free)(int id, void *p, void *data);

	unsigned int (*get_max_msg)(struct scmi_chan_info *base_cinfo);

	int (*send_message)(struct scmi_chan_info *cinfo,

			    struct scmi_xfer *xfer);

	void (*mark_txdone)(struct scmi_chan_info *cinfo, int ret);
@@ -390,8 +394,9 @@ struct scmi_device *scmi_child_dev_find(struct device *parent, 
 *		    de-initialization, so after SCMI core removal.

 * @ops: Pointer to the transport specific ops structure

 * @max_rx_timeout_ms: Timeout for communication with SoC (in Milliseconds)

 * @max_msg: Maximum number of messages that can be pending

 *	simultaneously in the system

 * @max_msg: Maximum number of messages for a channel type (tx or rx) that can

 *	be pending simultaneously in the system. May be overridden by the

 *	get_max_msg op.

 * @max_msg_size: Maximum size of data per message that can be handled.

 */

struct scmi_desc {

drivers/firmware/arm_scmi/driver.c

+36 −4
Original line number Diff line number Diff line
@@ -72,6 +72,7 @@ struct scmi_requested_dev { 
 *	Index of this bitmap table is also used for message

 *	sequence identifier.

 * @xfer_lock: Protection for message allocation

 * @max_msg: Maximum number of messages that can be pending

 * @free_xfers: A free list for available to use xfers. It is initialized with

 *		a number of xfers equal to the maximum allowed in-flight

 *		messages.
@@ -81,6 +82,7 @@ struct scmi_requested_dev { 
struct scmi_xfers_info {

	unsigned long *xfer_alloc_table;

	spinlock_t xfer_lock;

	int max_msg;

	struct hlist_head free_xfers;

	DECLARE_HASHTABLE(pending_xfers, SCMI_PENDING_XFERS_HT_ORDER_SZ);

};
@@ -1373,10 +1375,10 @@ static int __scmi_xfer_info_init(struct scmi_info *sinfo, 
	const struct scmi_desc *desc = sinfo->desc;



	/* Pre-allocated messages, no more than what hdr.seq can support */

	if (WARN_ON(!desc->max_msg || desc->max_msg > MSG_TOKEN_MAX)) {

	if (WARN_ON(!info->max_msg || info->max_msg > MSG_TOKEN_MAX)) {

		dev_err(dev,

			"Invalid maximum messages %d, not in range [1 - %lu]\n",

			desc->max_msg, MSG_TOKEN_MAX);

			info->max_msg, MSG_TOKEN_MAX);

		return -EINVAL;

	}
@@ -1394,7 +1396,7 @@ static int __scmi_xfer_info_init(struct scmi_info *sinfo, 
	 * attach all of them to the free list

	 */

	INIT_HLIST_HEAD(&info->free_xfers);

	for (i = 0; i < desc->max_msg; i++) {

	for (i = 0; i < info->max_msg; i++) {

		xfer = devm_kzalloc(dev, sizeof(*xfer), GFP_KERNEL);

		if (!xfer)

			return -ENOMEM;
@@ -1417,10 +1419,40 @@ static int __scmi_xfer_info_init(struct scmi_info *sinfo, 
	return 0;

}



static int scmi_channels_max_msg_configure(struct scmi_info *sinfo)

{

	const struct scmi_desc *desc = sinfo->desc;



	if (!desc->ops->get_max_msg) {

		sinfo->tx_minfo.max_msg = desc->max_msg;

		sinfo->rx_minfo.max_msg = desc->max_msg;

	} else {

		struct scmi_chan_info *base_cinfo;



		base_cinfo = idr_find(&sinfo->tx_idr, SCMI_PROTOCOL_BASE);

		if (!base_cinfo)

			return -EINVAL;

		sinfo->tx_minfo.max_msg = desc->ops->get_max_msg(base_cinfo);



		/* RX channel is optional so can be skipped */

		base_cinfo = idr_find(&sinfo->rx_idr, SCMI_PROTOCOL_BASE);

		if (base_cinfo)

			sinfo->rx_minfo.max_msg =

				desc->ops->get_max_msg(base_cinfo);

	}



	return 0;

}



static int scmi_xfer_info_init(struct scmi_info *sinfo)

{

	int ret = __scmi_xfer_info_init(sinfo, &sinfo->tx_minfo);

	int ret;



	ret = scmi_channels_max_msg_configure(sinfo);

	if (ret)

		return ret;



	ret = __scmi_xfer_info_init(sinfo, &sinfo->tx_minfo);

	if (!ret && idr_find(&sinfo->rx_idr, SCMI_PROTOCOL_BASE))

		ret = __scmi_xfer_info_init(sinfo, &sinfo->rx_minfo);