From patchwork Fri Mar 19 11:00:51 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: 12150803 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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=ham 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 68FFCC43331 for ; Fri, 19 Mar 2021 11:04:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E54D64F91 for ; Fri, 19 Mar 2021 11:04:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230170AbhCSLD6 (ORCPT ); Fri, 19 Mar 2021 07:03:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39182 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230519AbhCSLDq (ORCPT ); Fri, 19 Mar 2021 07:03:46 -0400 Received: from mail-pl1-x62c.google.com (mail-pl1-x62c.google.com [IPv6:2607:f8b0:4864:20::62c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 29996C06174A; Fri, 19 Mar 2021 04:03:46 -0700 (PDT) Received: by mail-pl1-x62c.google.com with SMTP id k4so2786197plk.5; Fri, 19 Mar 2021 04:03:46 -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=Bnr3nxKzCXX2teamhMKHsrHLZQg+RvaFqb+8NBtz+g0=; b=ONQ1EfmCsggbuatwu2Al09Qw7DWmqPTUz7i0LUvxTsFGIFMOJdbmi//5T8vxftN8Kk 8In2A/ACRd6XPfR5KtxECyKP83RrUcmyPq+vTvy+KTg5jH6o97dJIGbD/+sBrO1ee155 7tq+/kWGsn3nf9yode7H0HdmhdQofZ6x5+S11RiCMkQ7CtGEofijW2+VKBulZRts7SfA 0UZ8IGPTgLkemK5mmoymPvOPdEoWh1D9yinumlc+1kJH07CekzeyGq28bB64c4isa5IC DNKs7wvWYn2j7gnThtTqUNMwWaX0lMuMVJ9dkZnrvCY3O5ZlNx3VcqnvIaMM9+mc7JnC 6aSw== 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=Bnr3nxKzCXX2teamhMKHsrHLZQg+RvaFqb+8NBtz+g0=; b=iv1x7hbE+dMYEu0d/otrl9H1TlhyrG7MOfKFBmqXj6/YaVyATd8qf6DqUV73zVYfOy tQIupnfF/ht3SahbnXOrCX51lz4tkNnv0/m+Ug19ZQIOFPGKAMPOvDocyO2IzZ3jmSRA pF0mH/MTpfjaLYihdxELhQDJBYfipuyAeB7vxY2fpVb5Ha1T543YC/sViQuec38QDG3z KCzfAYW0pu0Je0kxedusSxSmqq176dKObWMNhYXOCm8707TGp3YoBgk9UZANJbUUelRS 4QTxEYcr507BTK5AHUN3s032Uo5kj4M0h8RFT0N5XxiioRfIRPlx5iWWAQGAs7eV5GBP diKA== X-Gm-Message-State: AOAM532b1QKOs9J2VHkGMyu8MPPU+g48o0nmyx3T1oRTXx0fx/DCd73g CSwc61sGNCfuWNZOpEry15w= X-Google-Smtp-Source: ABdhPJyciwuVESkzQty0MYJJFuLzCsQIKej8/IdadGHDuZY3dD+ZvyUk7yb/PbMZ10THXAT/ceUUrA== X-Received: by 2002:a17:90b:1007:: with SMTP id gm7mr9266147pjb.17.1616151825686; Fri, 19 Mar 2021 04:03:45 -0700 (PDT) Received: from localhost.localdomain ([156.146.35.76]) by smtp.gmail.com with ESMTPSA id i22sm4879042pjz.56.2021.03.19.04.03.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Mar 2021 04:03:45 -0700 (PDT) From: William Breathitt Gray To: jic23@kernel.org Cc: kernel@pengutronix.de, linux-stm32@st-md-mailman.stormreply.com, 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, William Breathitt Gray Subject: [PATCH v10 32/33] counter: 104-quad-8: Replace mutex with spinlock Date: Fri, 19 Mar 2021 20:00:51 +0900 Message-Id: <52016584522ed9b733cd52057f6974c274e34003.1616150619.git.vilhelm.gray@gmail.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: References: MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.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. Cc: Syed Nayyar Waris Signed-off-by: William Breathitt Gray Acked-by: Syed Nayyar Waris --- 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 eb7d63769f4c..d46b8101f207 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: - mutex_unlock(&priv->lock); + spin_unlock_irqrestore(&priv->lock, irqflags); quad8_preset_register_set(priv, count->id, ceiling); 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);