From patchwork Tue Aug 16 07:24:45 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Cristian Marussi X-Patchwork-Id: 12944395 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 29F7CC2BB41 for ; Tue, 16 Aug 2022 07:27:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=rfOgsB9SSb1UKIx31gts1cgmK85TyDsTK1LThULVT5Q=; b=tZZKNMbB0FPqhr o8Ff3j/8xRo3H2epgHbNNMLINIL8EZTT3n6w9kx/G14sbVZjGo3qYXA6rlMzQPtLlEJatyyMjVx6F i9aVPfN19s0UMqQFPfcBXaXrBF6OCm5HyK6EPP8bqy1WmfHtUyIr2Cp+b49J2YB2xGSY0iv5RZuJN HQPK6qEwXAhVtyN0INTXeIKBBJWZmx8qB3VAb8MxjKjOdpth6gO+xEssbDoufT5XDaTpceR2t1O3w 6TFr6w3ahbXmu9iBaDTIodLUam2XWzLNlqrnPjpQtcjnw6sNE8xvvwUMowxV7O9+TSiqqC81+sboG +fwkh1cvfU/Ogyw6Efbw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oNqx4-00F6P6-KY; Tue, 16 Aug 2022 07:25:26 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oNqws-00F61z-MC for linux-arm-kernel@lists.infradead.org; Tue, 16 Aug 2022 07:25:18 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 201321D31; Tue, 16 Aug 2022 00:25:10 -0700 (PDT) Received: from e120937-lin.home (unknown [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 83BA23F70D; Tue, 16 Aug 2022 00:25:07 -0700 (PDT) From: Cristian Marussi To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: sudeep.holla@arm.com, james.quinlan@broadcom.com, Jonathan.Cameron@Huawei.com, f.fainelli@gmail.com, etienne.carriere@linaro.org, vincent.guittot@linaro.org, souvik.chakravarty@arm.com, wleavitt@marvell.com, peter.hilber@opensynergy.com, nicola.mazzucato@arm.com, tarek.el-sherbiny@arm.com, cristian.marussi@arm.com Subject: [RFC PATCH 1/6] firmware: arm_scmi: Refactor xfer in-flight registration routines Date: Tue, 16 Aug 2022 08:24:45 +0100 Message-Id: <20220816072450.3120959-2-cristian.marussi@arm.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20220816072450.3120959-1-cristian.marussi@arm.com> References: <20220816072450.3120959-1-cristian.marussi@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220816_002514_890286_6710429A X-CRM114-Status: GOOD ( 17.75 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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 --- 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 609ebedee9cb..e5193da2ce09 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -311,8 +311,6 @@ 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; @@ -330,33 +328,77 @@ 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; @@ -376,25 +418,8 @@ 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; @@ -652,7 +677,7 @@ 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)); @@ -1041,13 +1066,22 @@ 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;