From patchwork Tue Aug 15 07:34:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Biju Das X-Patchwork-Id: 13353633 X-Patchwork-Delegate: geert@linux-m68k.org 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C1DCC04A6A for ; Tue, 15 Aug 2023 07:35:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234809AbjHOHfY (ORCPT ); Tue, 15 Aug 2023 03:35:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38810 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235207AbjHOHex (ORCPT ); Tue, 15 Aug 2023 03:34:53 -0400 Received: from relmlie5.idc.renesas.com (relmlor1.renesas.com [210.160.252.171]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 3E10B172C for ; Tue, 15 Aug 2023 00:34:52 -0700 (PDT) X-IronPort-AV: E=Sophos;i="6.01,174,1684767600"; d="scan'208";a="172983120" Received: from unknown (HELO relmlir6.idc.renesas.com) ([10.200.68.152]) by relmlie5.idc.renesas.com with ESMTP; 15 Aug 2023 16:34:52 +0900 Received: from localhost.localdomain (unknown [10.226.92.136]) by relmlir6.idc.renesas.com (Postfix) with ESMTP id 132B4417C107; Tue, 15 Aug 2023 16:34:49 +0900 (JST) From: Biju Das To: Lee Jones Cc: Biju Das , Geert Uytterhoeven , Pavel Machek , Prabhakar Mahadev Lad , linux-renesas-soc@vger.kernel.org Subject: [PATCH v2 1/2] mfd: rz-mtu3: Reduce critical sections Date: Tue, 15 Aug 2023 08:34:44 +0100 Message-Id: <20230815073445.9579-2-biju.das.jz@bp.renesas.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230815073445.9579-1-biju.das.jz@bp.renesas.com> References: <20230815073445.9579-1-biju.das.jz@bp.renesas.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org Reduce critical sections on rz_mtu3_start_stop_ch() and rz_mtu3_is_enabled() by moving offset and bitpos computation outside the critical section and drop the 'ret' variable on rz_mtu3_is_enabled() and return 'tstr & BIT(bitpos)' directly. Reported-by: Pavel Machek Closes: https://lore.kernel.org/all/ZIMAse1ikTuycJ02@duo.ucw.cz/ Signed-off-by: Biju Das Reviewed-by: Pavel Machek --- v1->v2: * Added Rb tag from Pavel * Updated Closes tag link. * Replaced "Improve critical sections"->"Reduce critical sections" in commit header and description. * Retained Rb tag as it is trivial change. --- drivers/mfd/rz-mtu3.c | 16 +++++++--------- 1 file changed, 7 insertions(+), 9 deletions(-) diff --git a/drivers/mfd/rz-mtu3.c b/drivers/mfd/rz-mtu3.c index 0156e381fe07..416eef1d1dfd 100644 --- a/drivers/mfd/rz-mtu3.c +++ b/drivers/mfd/rz-mtu3.c @@ -253,11 +253,12 @@ static void rz_mtu3_start_stop_ch(struct rz_mtu3_channel *ch, bool start) u16 offset; u8 bitpos; + offset = rz_mtu3_get_tstr_offset(ch); + bitpos = rz_mtu3_get_tstr_bit_pos(ch); + /* start stop register shared by multiple timer channels */ raw_spin_lock_irqsave(&priv->lock, flags); - offset = rz_mtu3_get_tstr_offset(ch); - bitpos = rz_mtu3_get_tstr_bit_pos(ch); tstr = rz_mtu3_shared_reg_read(ch, offset); __assign_bit(bitpos, &tstr, start); rz_mtu3_shared_reg_write(ch, offset, tstr); @@ -270,21 +271,18 @@ bool rz_mtu3_is_enabled(struct rz_mtu3_channel *ch) struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent); struct rz_mtu3_priv *priv = mtu->priv_data; unsigned long flags, tstr; - bool ret = false; u16 offset; u8 bitpos; - /* start stop register shared by multiple timer channels */ - raw_spin_lock_irqsave(&priv->lock, flags); - offset = rz_mtu3_get_tstr_offset(ch); bitpos = rz_mtu3_get_tstr_bit_pos(ch); - tstr = rz_mtu3_shared_reg_read(ch, offset); - ret = tstr & BIT(bitpos); + /* start stop register shared by multiple timer channels */ + raw_spin_lock_irqsave(&priv->lock, flags); + tstr = rz_mtu3_shared_reg_read(ch, offset); raw_spin_unlock_irqrestore(&priv->lock, flags); - return ret; + return tstr & BIT(bitpos); } EXPORT_SYMBOL_GPL(rz_mtu3_is_enabled); From patchwork Tue Aug 15 07:34:45 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Biju Das X-Patchwork-Id: 13353634 X-Patchwork-Delegate: geert@linux-m68k.org 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9AA55C001DE for ; Tue, 15 Aug 2023 07:35:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235172AbjHOHf0 (ORCPT ); Tue, 15 Aug 2023 03:35:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52588 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235267AbjHOHe5 (ORCPT ); Tue, 15 Aug 2023 03:34:57 -0400 Received: from relmlie6.idc.renesas.com (relmlor2.renesas.com [210.160.252.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1D1461989 for ; Tue, 15 Aug 2023 00:34:54 -0700 (PDT) X-IronPort-AV: E=Sophos;i="6.01,174,1684767600"; d="scan'208";a="176668734" Received: from unknown (HELO relmlir6.idc.renesas.com) ([10.200.68.152]) by relmlie6.idc.renesas.com with ESMTP; 15 Aug 2023 16:34:54 +0900 Received: from localhost.localdomain (unknown [10.226.92.136]) by relmlir6.idc.renesas.com (Postfix) with ESMTP id 9018F417BE7E; Tue, 15 Aug 2023 16:34:52 +0900 (JST) From: Biju Das To: Lee Jones Cc: Biju Das , Geert Uytterhoeven , Pavel Machek , Prabhakar Mahadev Lad , linux-renesas-soc@vger.kernel.org Subject: [PATCH v2 2/2] mfd: rz-mtu3: Replace raw_spin_lock->spin_lock() Date: Tue, 15 Aug 2023 08:34:45 +0100 Message-Id: <20230815073445.9579-3-biju.das.jz@bp.renesas.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230815073445.9579-1-biju.das.jz@bp.renesas.com> References: <20230815073445.9579-1-biju.das.jz@bp.renesas.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-renesas-soc@vger.kernel.org As per kernel documentation, use raw_spinlock_t only in real critical core code, low-level interrupt handling, and places where disabling preemption or interrupts is required. Here the lock is for concurrent register access from different drivers, hence spin_lock() is sufficient. Reported-by: Pavel Machek Closes: https://lore.kernel.org/all/ZIL%2FitcJvV5s3Bnf@duo.ucw.cz/ Signed-off-by: Biju Das Reviewed-by: Pavel Machek --- v1->v2: * Rebased to next. * Updated Closes tag link. --- drivers/mfd/rz-mtu3.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/mfd/rz-mtu3.c b/drivers/mfd/rz-mtu3.c index 416eef1d1dfd..19afdd8e96fe 100644 --- a/drivers/mfd/rz-mtu3.c +++ b/drivers/mfd/rz-mtu3.c @@ -23,7 +23,7 @@ struct rz_mtu3_priv { void __iomem *mmio; struct reset_control *rstc; - raw_spinlock_t lock; + spinlock_t lock; }; /******* MTU3 registers (original offset is +0x1200) *******/ @@ -177,11 +177,11 @@ void rz_mtu3_shared_reg_update_bit(struct rz_mtu3_channel *ch, u16 offset, struct rz_mtu3_priv *priv = mtu->priv_data; unsigned long tmdr, flags; - raw_spin_lock_irqsave(&priv->lock, flags); + spin_lock_irqsave(&priv->lock, flags); tmdr = rz_mtu3_shared_reg_read(ch, offset); __assign_bit(pos, &tmdr, !!val); rz_mtu3_shared_reg_write(ch, offset, tmdr); - raw_spin_unlock_irqrestore(&priv->lock, flags); + spin_unlock_irqrestore(&priv->lock, flags); } EXPORT_SYMBOL_GPL(rz_mtu3_shared_reg_update_bit); @@ -257,13 +257,13 @@ static void rz_mtu3_start_stop_ch(struct rz_mtu3_channel *ch, bool start) bitpos = rz_mtu3_get_tstr_bit_pos(ch); /* start stop register shared by multiple timer channels */ - raw_spin_lock_irqsave(&priv->lock, flags); + spin_lock_irqsave(&priv->lock, flags); tstr = rz_mtu3_shared_reg_read(ch, offset); __assign_bit(bitpos, &tstr, start); rz_mtu3_shared_reg_write(ch, offset, tstr); - raw_spin_unlock_irqrestore(&priv->lock, flags); + spin_unlock_irqrestore(&priv->lock, flags); } bool rz_mtu3_is_enabled(struct rz_mtu3_channel *ch) @@ -278,9 +278,9 @@ bool rz_mtu3_is_enabled(struct rz_mtu3_channel *ch) bitpos = rz_mtu3_get_tstr_bit_pos(ch); /* start stop register shared by multiple timer channels */ - raw_spin_lock_irqsave(&priv->lock, flags); + spin_lock_irqsave(&priv->lock, flags); tstr = rz_mtu3_shared_reg_read(ch, offset); - raw_spin_unlock_irqrestore(&priv->lock, flags); + spin_unlock_irqrestore(&priv->lock, flags); return tstr & BIT(bitpos); } @@ -350,7 +350,7 @@ static int rz_mtu3_probe(struct platform_device *pdev) return PTR_ERR(ddata->clk); reset_control_deassert(priv->rstc); - raw_spin_lock_init(&priv->lock); + spin_lock_init(&priv->lock); platform_set_drvdata(pdev, ddata); for (i = 0; i < RZ_MTU_NUM_CHANNELS; i++) {