From patchwork Tue Jul 13 09:53:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: William Breathitt Gray X-Patchwork-Id: 12373427 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA7A9C07E95 for ; Tue, 13 Jul 2021 10:10:16 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id B73FB611CB for ; Tue, 13 Jul 2021 10:10:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B73FB611CB Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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=VY121+QrHXnULDcGZqusMmU6BpNOvyjLDQvTo2jN3+E=; b=ldrcQa1inqCQbs AVOAbHltYTxg2k0aEeSVRSXyGtF7KSq7VIDWMpKmw4E1XYJBEQn+XSI1C96yye0D79D4jLShhX3xL Ji4yIJp65uCYVGB+Pr2SnPR4s6sNsZZLSzKuIzeFMGfnAW9eb83sUQv9WcAX62OmvosYiA5s1cUoE 62n/NCK3OVLzvNvbzw0oC4G478nCaqZLezkMueBlaiyayp8pvcl63OqMy++TqebJJS4KrT/Sy5wl4 dY/mLz20UOh53Z82SNMkZIz/8NBI82GEa/zkWJNYjjSHHnGAPKr41/a/N1nV9ndPjdlhAz4AopKvh Mxidc3tTmXvZtT33SHZA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1m3FKk-009omm-PY; Tue, 13 Jul 2021 10:08:11 +0000 Received: from mail-pl1-x635.google.com ([2607:f8b0:4864:20::635]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1m3F87-009jyH-Uv for linux-arm-kernel@lists.infradead.org; Tue, 13 Jul 2021 09:55:10 +0000 Received: by mail-pl1-x635.google.com with SMTP id d1so5610888plg.0 for ; Tue, 13 Jul 2021 02:55:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=HeByZWfWDzFovzvjp6wXVFR3lWTc9L7uXKk6mjE/Rik=; b=bV29LA+EGVeIqj+7VWOVEzBOMMQCH6Hn6LcwS2WX9B1jXNxzsr7ITPuNWY0M1T6EqY Cq4pPESRDSDaET2FyGTjzh4EZTRCm8Jw5d7G82mhbF2ILTu+9+G8Yy3eAC1nEwQjgxFh WPvIbTzGecxVOg6TRy01dksOaCZXXhEn8049laRuDR42gVuQRMxUSaebTNIlBhvpH7GL hYMTMA0bGTR8OeYEN/TbwuifrZAdV8IJYZCdQlwsfxPtRORTwPE1pGD8G9jKs8SmZj1t mdh4rvFBYxeiFK6z4XQTcixZL16yeBEVp9xYApmKlcCbxTqCkEeJrxYMd9ja44rezlc1 A8Uw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=HeByZWfWDzFovzvjp6wXVFR3lWTc9L7uXKk6mjE/Rik=; b=WtZIOZjjF+sTcfg1JL++m/7/g1pJWEYWnB6lpZzG2vkK0PLCdZKpmX89mBMpiPpOov gLraxA+GtJ51AtSgAjGUC90GdfnsfZdwU79M019J0GW/dvgAMC9sk8olnd/VH7ZMw1c/ 8Ssf+dxAWFPPrTyFyaTfMjHv3nXQsHDo1HqHrYxytLoamLeH2pnx0UEGp719p12S83sV ofcWnYAipvT7X1OUuaCvDinjygGNbTXCNyK4LSeo8U8eaHFOhsWMLu9NmSrwyRlpJV7r yJPhD7HwMqIgmZuPWjkHYKp8QUq1ac/FmsOzsoJ7jaDpBeT5z5aNetBpMpKf4Pd57Uf2 X6Fw== X-Gm-Message-State: AOAM533iPcOXXNNA8rFScq0rsPm9NVnkiJjb7alfsJtDo1/gwOS9hxWs mXCicvqFP2+iewGFXQDw7mQ= X-Google-Smtp-Source: ABdhPJwbRJ4k2R/+Da38jB64gAi9TZWd2thhM85bJeIV/CNV1fzhwfUjs/BiE3CSoA6yfzAp+nipDw== X-Received: by 2002:a17:90a:6d89:: with SMTP id a9mr18678430pjk.194.1626170106960; Tue, 13 Jul 2021 02:55:06 -0700 (PDT) Received: from localhost.localdomain ([156.146.35.76]) by smtp.gmail.com with ESMTPSA id f6sm18153854pfj.28.2021.07.13.02.55.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 13 Jul 2021 02:55:06 -0700 (PDT) From: William Breathitt Gray To: jic23@kernel.org Cc: linux-stm32@st-md-mailman.stormreply.com, kernel@pengutronix.de, a.fatoum@pengutronix.de, kamel.bouhara@bootlin.com, gwendal@chromium.org, alexandre.belloni@bootlin.com, david@lechnology.com, linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, syednwaris@gmail.com, patrick.havelange@essensium.com, fabrice.gasnier@st.com, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com, o.rempel@pengutronix.de, jarkko.nikula@linux.intel.com, William Breathitt Gray Subject: [PATCH v13 16/17] counter: 104-quad-8: Replace mutex with spinlock Date: Tue, 13 Jul 2021 18:53:20 +0900 Message-Id: <84ee735564be49fc1bcc55985f47e34a78ad3287.1626165765.git.vilhelm.gray@gmail.com> X-Mailer: git-send-email 2.32.0 In-Reply-To: References: MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210713_025508_090588_DF4DDAA7 X-CRM114-Status: GOOD ( 19.03 ) 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 This patch replaces the mutex I/O lock with a spinlock. This is in preparation for a subsequent patch adding IRQ support for 104-QUAD-8 devices; we can't sleep in an interrupt context, so we'll need to use a spinlock instead. Acked-by: Syed Nayyar Waris Signed-off-by: William Breathitt Gray --- drivers/counter/104-quad-8.c | 90 +++++++++++++++++++++--------------- 1 file changed, 53 insertions(+), 37 deletions(-) diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c index d1161c27c488..a56751bf1e9b 100644 --- a/drivers/counter/104-quad-8.c +++ b/drivers/counter/104-quad-8.c @@ -16,6 +16,7 @@ #include #include #include +#include #define QUAD8_EXTENT 32 @@ -28,6 +29,7 @@ MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses"); /** * struct quad8 - device private data structure + * @lock: lock to prevent clobbering device states during R/W ops * @counter: instance of the counter_device * @fck_prescaler: array of filter clock prescaler configurations * @preset: array of preset values @@ -42,7 +44,7 @@ MODULE_PARM_DESC(base, "ACCES 104-QUAD-8 base addresses"); * @base: base port address of the device */ struct quad8 { - struct mutex lock; + spinlock_t lock; struct counter_device counter; unsigned int fck_prescaler[QUAD8_NUM_COUNTERS]; unsigned int preset[QUAD8_NUM_COUNTERS]; @@ -123,6 +125,7 @@ static int quad8_count_read(struct counter_device *counter, unsigned int flags; unsigned int borrow; unsigned int carry; + unsigned long irqflags; int i; flags = inb(base_offset + 1); @@ -132,7 +135,7 @@ static int quad8_count_read(struct counter_device *counter, /* Borrow XOR Carry effectively doubles count range */ *val = (unsigned long)(borrow ^ carry) << 24; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); /* Reset Byte Pointer; transfer Counter to Output Latch */ outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_CNTR_OUT, @@ -141,7 +144,7 @@ static int quad8_count_read(struct counter_device *counter, for (i = 0; i < 3; i++) *val |= (unsigned long)inb(base_offset) << (8 * i); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -151,13 +154,14 @@ static int quad8_count_write(struct counter_device *counter, { struct quad8 *const priv = counter->priv; const int base_offset = priv->base + 2 * count->id; + unsigned long irqflags; int i; /* Only 24-bit values are supported */ if (val > 0xFFFFFF) return -ERANGE; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); /* Reset Byte Pointer */ outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP, base_offset + 1); @@ -182,7 +186,7 @@ static int quad8_count_write(struct counter_device *counter, /* Reset Error flag */ outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_E, base_offset + 1); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -200,8 +204,9 @@ static int quad8_function_read(struct counter_device *counter, { struct quad8 *const priv = counter->priv; const int id = count->id; + unsigned long irqflags; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); if (priv->quadrature_mode[id]) switch (priv->quadrature_scale[id]) { @@ -218,7 +223,7 @@ static int quad8_function_read(struct counter_device *counter, else *function = COUNTER_FUNCTION_PULSE_DIRECTION; - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -233,10 +238,11 @@ static int quad8_function_write(struct counter_device *counter, unsigned int *const scale = priv->quadrature_scale + id; unsigned int *const synchronous_mode = priv->synchronous_mode + id; const int base_offset = priv->base + 2 * id + 1; + unsigned long irqflags; unsigned int mode_cfg; unsigned int idr_cfg; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); mode_cfg = priv->count_mode[id] << 1; idr_cfg = priv->index_polarity[id] << 1; @@ -271,7 +277,7 @@ static int quad8_function_write(struct counter_device *counter, break; default: /* should never reach this path */ - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return -EINVAL; } } @@ -279,7 +285,7 @@ static int quad8_function_write(struct counter_device *counter, /* Load mode configuration to Counter Mode Register */ outb(QUAD8_CTR_CMR | mode_cfg, base_offset); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -405,9 +411,10 @@ static int quad8_index_polarity_set(struct counter_device *counter, struct quad8 *const priv = counter->priv; const size_t channel_id = signal->id - 16; const int base_offset = priv->base + 2 * channel_id + 1; + unsigned long irqflags; unsigned int idr_cfg = index_polarity << 1; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); idr_cfg |= priv->synchronous_mode[channel_id]; @@ -416,7 +423,7 @@ static int quad8_index_polarity_set(struct counter_device *counter, /* Load Index Control configuration to Index Control Register */ outb(QUAD8_CTR_IDR | idr_cfg, base_offset); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -445,15 +452,16 @@ static int quad8_synchronous_mode_set(struct counter_device *counter, struct quad8 *const priv = counter->priv; const size_t channel_id = signal->id - 16; const int base_offset = priv->base + 2 * channel_id + 1; + unsigned long irqflags; unsigned int idr_cfg = synchronous_mode; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); idr_cfg |= priv->index_polarity[channel_id] << 1; /* Index function must be non-synchronous in non-quadrature mode */ if (synchronous_mode && !priv->quadrature_mode[channel_id]) { - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return -EINVAL; } @@ -462,7 +470,7 @@ static int quad8_synchronous_mode_set(struct counter_device *counter, /* Load Index Control configuration to Index Control Register */ outb(QUAD8_CTR_IDR | idr_cfg, base_offset); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -509,6 +517,7 @@ static int quad8_count_mode_write(struct counter_device *counter, unsigned int count_mode; unsigned int mode_cfg; const int base_offset = priv->base + 2 * count->id + 1; + unsigned long irqflags; /* Map Generic Counter count mode to 104-QUAD-8 count mode */ switch (cnt_mode) { @@ -529,7 +538,7 @@ static int quad8_count_mode_write(struct counter_device *counter, return -EINVAL; } - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); priv->count_mode[count->id] = count_mode; @@ -543,7 +552,7 @@ static int quad8_count_mode_write(struct counter_device *counter, /* Load mode configuration to Counter Mode Register */ outb(QUAD8_CTR_CMR | mode_cfg, base_offset); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -563,9 +572,10 @@ static int quad8_count_enable_write(struct counter_device *counter, { struct quad8 *const priv = counter->priv; const int base_offset = priv->base + 2 * count->id; + unsigned long irqflags; unsigned int ior_cfg; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); priv->ab_enable[count->id] = enable; @@ -574,7 +584,7 @@ static int quad8_count_enable_write(struct counter_device *counter, /* Load I/O control configuration */ outb(QUAD8_CTR_IOR | ior_cfg, base_offset + 1); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -625,16 +635,17 @@ static int quad8_count_preset_write(struct counter_device *counter, struct counter_count *count, u64 preset) { struct quad8 *const priv = counter->priv; + unsigned long irqflags; /* Only 24-bit values are supported */ if (preset > 0xFFFFFF) return -ERANGE; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); quad8_preset_register_set(priv, count->id, preset); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -643,8 +654,9 @@ static int quad8_count_ceiling_read(struct counter_device *counter, struct counter_count *count, u64 *ceiling) { struct quad8 *const priv = counter->priv; + unsigned long irqflags; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); /* Range Limit and Modulo-N count modes use preset value as ceiling */ switch (priv->count_mode[count->id]) { @@ -658,7 +670,7 @@ static int quad8_count_ceiling_read(struct counter_device *counter, break; } - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -667,23 +679,24 @@ static int quad8_count_ceiling_write(struct counter_device *counter, struct counter_count *count, u64 ceiling) { struct quad8 *const priv = counter->priv; + unsigned long irqflags; /* Only 24-bit values are supported */ if (ceiling > 0xFFFFFF) return -ERANGE; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); /* Range Limit and Modulo-N count modes use preset value as ceiling */ switch (priv->count_mode[count->id]) { case 1: case 3: quad8_preset_register_set(priv, count->id, ceiling); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return -EINVAL; } @@ -705,12 +718,13 @@ static int quad8_count_preset_enable_write(struct counter_device *counter, { struct quad8 *const priv = counter->priv; const int base_offset = priv->base + 2 * count->id + 1; + unsigned long irqflags; unsigned int ior_cfg; /* Preset enable is active low in Input/Output Control register */ preset_enable = !preset_enable; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); priv->preset_enable[count->id] = preset_enable; @@ -719,7 +733,7 @@ static int quad8_count_preset_enable_write(struct counter_device *counter, /* Load I/O control configuration to Input / Output Control Register */ outb(QUAD8_CTR_IOR | ior_cfg, base_offset); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -730,22 +744,23 @@ static int quad8_signal_cable_fault_read(struct counter_device *counter, { struct quad8 *const priv = counter->priv; const size_t channel_id = signal->id / 2; + unsigned long irqflags; bool disabled; unsigned int status; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); disabled = !(priv->cable_fault_enable & BIT(channel_id)); if (disabled) { - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return -EINVAL; } /* Logic 0 = cable fault */ status = inb(priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); /* Mask respective channel and invert logic */ *cable_fault = !(status & BIT(channel_id)); @@ -771,9 +786,10 @@ static int quad8_signal_cable_fault_enable_write(struct counter_device *counter, { struct quad8 *const priv = counter->priv; const size_t channel_id = signal->id / 2; + unsigned long irqflags; unsigned int cable_fault_enable; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); if (enable) priv->cable_fault_enable |= BIT(channel_id); @@ -785,7 +801,7 @@ static int quad8_signal_cable_fault_enable_write(struct counter_device *counter, outb(cable_fault_enable, priv->base + QUAD8_DIFF_ENCODER_CABLE_STATUS); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -808,8 +824,9 @@ static int quad8_signal_fck_prescaler_write(struct counter_device *counter, struct quad8 *const priv = counter->priv; const size_t channel_id = signal->id / 2; const int base_offset = priv->base + 2 * channel_id; + unsigned long irqflags; - mutex_lock(&priv->lock); + spin_lock_irqsave(&priv->lock, irqflags); priv->fck_prescaler[channel_id] = prescaler; @@ -821,7 +838,7 @@ static int quad8_signal_fck_prescaler_write(struct counter_device *counter, outb(QUAD8_CTR_RLD | QUAD8_RLD_RESET_BP | QUAD8_RLD_PRESET_PSC, base_offset + 1); - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); return 0; } @@ -990,8 +1007,7 @@ static int quad8_probe(struct device *dev, unsigned int id) priv->counter.priv = priv; priv->base = base[id]; - /* Initialize mutex */ - mutex_init(&priv->lock); + spin_lock_init(&priv->lock); /* Reset all counters and disable interrupt function */ outb(QUAD8_CHAN_OP_RESET_COUNTERS, base[id] + QUAD8_REG_CHAN_OP);