Commit b0e924a9 authored by Cristian Marussi's avatar Cristian Marussi Committed by Sudeep Holla
Browse files

firmware: arm_scmi: Refactor xfer in-flight registration routines 



Move the whole xfer in-flight registration process out of scmi_xfer_get
and while at that, split the sequence number selection steps from the
in-flight registration procedure itself.

No functional change.

Signed-off-by: default avatarCristian Marussi <cristian.marussi@arm.com>
Tested-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Tested-by: default avatarVincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20230118121426.492864-2-cristian.marussi@arm.com


Signed-off-by: default avatarSudeep Holla <sudeep.holla@arm.com>
parent 37b5be82

drivers/firmware/arm_scmi/driver.c

+68 −34
Original line number Diff line number Diff line
@@ -411,8 +411,6 @@ static int scmi_xfer_token_set(struct scmi_xfers_info *minfo, 
	if (xfer_id != next_token)

		atomic_add((int)(xfer_id - next_token), &transfer_last_id);



	/* Set in-flight */

	set_bit(xfer_id, minfo->xfer_alloc_table);

	xfer->hdr.seq = (u16)xfer_id;



	return 0;
@@ -430,33 +428,77 @@ static inline void scmi_xfer_token_clear(struct scmi_xfers_info *minfo, 
	clear_bit(xfer->hdr.seq, minfo->xfer_alloc_table);

}



/**

 * scmi_xfer_inflight_register_unlocked  - Register the xfer as in-flight

 *

 * @xfer: The xfer to register

 * @minfo: Pointer to Tx/Rx Message management info based on channel type

 *

 * Note that this helper assumes that the xfer to be registered as in-flight

 * had been built using an xfer sequence number which still corresponds to a

 * free slot in the xfer_alloc_table.

 *

 * Context: Assumes to be called with @xfer_lock already acquired.

 */

static inline void

scmi_xfer_inflight_register_unlocked(struct scmi_xfer *xfer,

				     struct scmi_xfers_info *minfo)

{

	/* Set in-flight */

	set_bit(xfer->hdr.seq, minfo->xfer_alloc_table);

	hash_add(minfo->pending_xfers, &xfer->node, xfer->hdr.seq);

	xfer->pending = true;

}



/**

 * scmi_xfer_pending_set  - Pick a proper sequence number and mark the xfer

 * as pending in-flight

 *

 * @xfer: The xfer to act upon

 * @minfo: Pointer to Tx/Rx Message management info based on channel type

 *

 * Return: 0 on Success or error otherwise

 */

static inline int scmi_xfer_pending_set(struct scmi_xfer *xfer,

					struct scmi_xfers_info *minfo)

{

	int ret;

	unsigned long flags;



	spin_lock_irqsave(&minfo->xfer_lock, flags);

	/* Set a new monotonic token as the xfer sequence number */

	ret = scmi_xfer_token_set(minfo, xfer);

	if (!ret)

		scmi_xfer_inflight_register_unlocked(xfer, minfo);

	spin_unlock_irqrestore(&minfo->xfer_lock, flags);



	return ret;

}



/**

 * scmi_xfer_get() - Allocate one message

 *

 * @handle: Pointer to SCMI entity handle

 * @minfo: Pointer to Tx/Rx Message management info based on channel type

 * @set_pending: If true a monotonic token is picked and the xfer is added to

 *		 the pending hash table.

 *

 * Helper function which is used by various message functions that are

 * exposed to clients of this driver for allocating a message traffic event.

 *

 * Picks an xfer from the free list @free_xfers (if any available) and, if

 * required, sets a monotonically increasing token and stores the inflight xfer

 * into the @pending_xfers hashtable for later retrieval.

 * Picks an xfer from the free list @free_xfers (if any available) and perform

 * a basic initialization.

 *

 * Note that, at this point, still no sequence number is assigned to the

 * allocated xfer, nor it is registered as a pending transaction.

 *

 * The successfully initialized xfer is refcounted.

 *

 * Context: Holds @xfer_lock while manipulating @xfer_alloc_table and

 *	    @free_xfers.

 * Context: Holds @xfer_lock while manipulating @free_xfers.

 *

 * Return: 0 if all went fine, else corresponding error.

 * Return: An initialized xfer if all went fine, else pointer error.

 */

static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle,

				       struct scmi_xfers_info *minfo,

				       bool set_pending)

				       struct scmi_xfers_info *minfo)

{

	int ret;

	unsigned long flags;

	struct scmi_xfer *xfer;
@@ -476,25 +518,8 @@ static struct scmi_xfer *scmi_xfer_get(const struct scmi_handle *handle, 
	 */

	xfer->transfer_id = atomic_inc_return(&transfer_last_id);



	if (set_pending) {

		/* Pick and set monotonic token */

		ret = scmi_xfer_token_set(minfo, xfer);

		if (!ret) {

			hash_add(minfo->pending_xfers, &xfer->node,

				 xfer->hdr.seq);

			xfer->pending = true;

		} else {

			dev_err(handle->dev,

				"Failed to get monotonic token %d\n", ret);

			hlist_add_head(&xfer->node, &minfo->free_xfers);

			xfer = ERR_PTR(ret);

		}

	}



	if (!IS_ERR(xfer)) {

	refcount_set(&xfer->users, 1);

	atomic_set(&xfer->busy, SCMI_XFER_FREE);

	}

	spin_unlock_irqrestore(&minfo->xfer_lock, flags);



	return xfer;
@@ -752,7 +777,7 @@ static void scmi_handle_notification(struct scmi_chan_info *cinfo, 
	ktime_t ts;



	ts = ktime_get_boottime();

	xfer = scmi_xfer_get(cinfo->handle, minfo, false);

	xfer = scmi_xfer_get(cinfo->handle, minfo);

	if (IS_ERR(xfer)) {

		dev_err(dev, "failed to get free message slot (%ld)\n",

			PTR_ERR(xfer));
@@ -1143,13 +1168,22 @@ static int xfer_get_init(const struct scmi_protocol_handle *ph, 
	    tx_size > info->desc->max_msg_size)

		return -ERANGE;



	xfer = scmi_xfer_get(pi->handle, minfo, true);

	xfer = scmi_xfer_get(pi->handle, minfo);

	if (IS_ERR(xfer)) {

		ret = PTR_ERR(xfer);

		dev_err(dev, "failed to get free message slot(%d)\n", ret);

		return ret;

	}



	/* Pick a sequence number and register this xfer as in-flight */

	ret = scmi_xfer_pending_set(xfer, minfo);

	if (ret) {

		dev_err(pi->handle->dev,

			"Failed to get monotonic token %d\n", ret);

		__scmi_xfer_put(minfo, xfer);

		return ret;

	}



	xfer->tx.len = tx_size;

	xfer->rx.len = rx_size ? : info->desc->max_msg_size;

	xfer->hdr.type = MSG_TYPE_COMMAND;