From b0e924a955cb9e9da759a7a2940f35679864222f Mon Sep 17 00:00:00 2001 From: Cristian Marussi Date: Wed, 18 Jan 2023 12:14:10 +0000 Subject: [PATCH] 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: Cristian Marussi Tested-by: Florian Fainelli Tested-by: Vincent Guittot Link: https://lore.kernel.org/r/20230118121426.492864-2-cristian.marussi@arm.com Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/driver.c | 102 ++++++++++++++++++++++++------------- 1 file changed, 68 insertions(+), 34 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 50267ee..3400bd1 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -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; @@ -431,32 +429,76 @@ static inline void scmi_xfer_token_clear(struct scmi_xfers_info *minfo, } /** + * 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); - } + 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; -- 2.7.4