From patchwork Sun Apr 3 17:55:40 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Gerhard Engleder X-Patchwork-Id: 12799662 X-Patchwork-Delegate: kuba@kernel.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 86D3AC4332F for ; Sun, 3 Apr 2022 17:56:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241715AbiDCR6X (ORCPT ); Sun, 3 Apr 2022 13:58:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50376 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1359712AbiDCR6K (ORCPT ); Sun, 3 Apr 2022 13:58:10 -0400 Received: from mail-ed1-x52e.google.com (mail-ed1-x52e.google.com [IPv6:2a00:1450:4864:20::52e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C400838BC3 for ; Sun, 3 Apr 2022 10:55:59 -0700 (PDT) Received: by mail-ed1-x52e.google.com with SMTP id b24so8506174edu.10 for ; Sun, 03 Apr 2022 10:55:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=engleder-embedded-com.20210112.gappssmtp.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=CnjlWhysPRTkp9rGG1iCRqY0fG2HcVGyZm/JObISTGY=; b=n6YCJC+ds9WInEHMqk9oLdSQc5UklvQt/YcJ+q7x648AevVMkCt9YFktffj3h4N5o5 q4anA9THQBoXomnivcNLDwGe1Npxz4A3TwI9tFYctv3247FuoQAK3Y9acjOCZ6mQNmWH xwqAQoDsqx4s6H5z6lGdrFfsSNNtxwFyKhOYXZm5iFhCuDkdmcFUfIa/BDHvyW1+C5Ec mvnxSrs38k/KAOtPpR8cGTMZHyLorgi8oZSYu8SUi8vWPMoAIlvvJ0ePgRR0yLYOD2fi oofxLccao8VyOlG1gT7TQOaCAHuZKez0SqSGkpisbslvGmbWn4gkH3BdWPMH2VD6Bwa5 GO7w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=CnjlWhysPRTkp9rGG1iCRqY0fG2HcVGyZm/JObISTGY=; b=X/ve7eosdcD6Gcahygg1IkepoSwYmOuM6S8+ZOqaYXrq4z5VVyDj7AH2bu2dBapYHw DMTNVa5BkU3KpyoOoI3b6p98tRYjqyMH9Xvk7b0WraaCUddw3HJ2cluqCsFOJkXDJ2wV AeOs6mAUCRvvTqMXDFEnmh/rAOezDg/M8CF0pt9i8hOD4kWgvqxBsXx5R6JTPdjcknDH tkda2hJPPIxG6POaBnXQBGEkfYh0JGc5VOI8Ify8jlmjxYPcLDpXZcglLKL6Orirq8Ct gULL3/zyItKbk+y6c3T2JDhxcYHy6IZnTYFACB6qZ/OMGULIdL+P9pHho2ow15XskjEc ZYJw== X-Gm-Message-State: AOAM530xafoVoyZtr3LPwbw5oFccn64GxUTMOrdr+LA4t4STCuW/Bmo7 npopvJ+DdB+xM9BIy6g1hHeHOaDGrLWQs6If X-Google-Smtp-Source: ABdhPJwZm/O/bExIo0jFIOMmGlwtJ3s/1KhTg+e3wdxGU5SCQiRKrIjmkIKeF+unv9VN0Blj3sLNcQ== X-Received: by 2002:a05:6402:1385:b0:413:2bc6:4400 with SMTP id b5-20020a056402138500b004132bc64400mr30288727edv.94.1649008558251; Sun, 03 Apr 2022 10:55:58 -0700 (PDT) Received: from hornet.engleder.at ([2001:871:23a:8366:6e3b:e5ff:fe2c:34c1]) by smtp.gmail.com with ESMTPSA id q7-20020a170906540700b006d5eca5c9cfsm3451065ejo.191.2022.04.03.10.55.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 03 Apr 2022 10:55:57 -0700 (PDT) From: Gerhard Engleder To: richardcochran@gmail.com, vinicius.gomes@intel.com, yangbo.lu@nxp.com, davem@davemloft.net, kuba@kernel.org Cc: mlichvar@redhat.com, netdev@vger.kernel.org, Gerhard Engleder Subject: [PATCH net-next v2 1/5] ptp: Add cycles support for virtual clocks Date: Sun, 3 Apr 2022 19:55:40 +0200 Message-Id: <20220403175544.26556-2-gerhard@engleder-embedded.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20220403175544.26556-1-gerhard@engleder-embedded.com> References: <20220403175544.26556-1-gerhard@engleder-embedded.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org ptp vclocks require a free running time for their timecounter. Currently only a physical clock forced to free running is supported. If vclocks are used, then the physical clock cannot be synchronized anymore. The synchronized time is not available in hardware in this case. As a result, timed transmission with TAPRIO hardware support is not possible anymore. If hardware would support a free running time additionally to the physical clock, then the physical clock does not need to be forced to free running. Thus, the physical clocks can still be synchronized while vclocks are in use. The physical clock could be used to synchronize the time domain of the TSN network and trigger TAPRIO. In parallel vclocks can be used to synchronize other time domains. Introduce support for a free running cycle counter called cycles to physical clocks. Rework ptp vclocks to use this free running cycle counter. Default implementation is based on time of physical clock. Thus, behavior of ptp vclocks based on physical clocks without free running cycle counter is identical to previous behavior. Signed-off-by: Gerhard Engleder --- drivers/ptp/ptp_clock.c | 31 +++++++++++++++++++++++++++---- drivers/ptp/ptp_private.h | 10 ++++++++++ drivers/ptp/ptp_sysfs.c | 10 ++++++---- drivers/ptp/ptp_vclock.c | 13 +++++-------- include/linux/ptp_clock_kernel.h | 31 +++++++++++++++++++++++++++++++ 5 files changed, 79 insertions(+), 16 deletions(-) diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c index b6f2cfd15dd2..11b8190807c3 100644 --- a/drivers/ptp/ptp_clock.c +++ b/drivers/ptp/ptp_clock.c @@ -77,8 +77,8 @@ static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp { struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); - if (ptp_vclock_in_use(ptp)) { - pr_err("ptp: virtual clock in use\n"); + if (ptp_clock_freerun(ptp)) { + pr_err("ptp: physical clock is free running\n"); return -EBUSY; } @@ -103,8 +103,8 @@ static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx) struct ptp_clock_info *ops; int err = -EOPNOTSUPP; - if (ptp_vclock_in_use(ptp)) { - pr_err("ptp: virtual clock in use\n"); + if (ptp_clock_freerun(ptp)) { + pr_err("ptp: physical clock is free running\n"); return -EBUSY; } @@ -178,6 +178,14 @@ static void ptp_clock_release(struct device *dev) kfree(ptp); } +static int ptp_getcycles64(struct ptp_clock_info *info, struct timespec64 *ts) +{ + if (info->getcyclesx64) + return info->getcyclesx64(info, ts, NULL); + else + return info->gettime64(info, ts); +} + static void ptp_aux_kworker(struct kthread_work *work) { struct ptp_clock *ptp = container_of(work, struct ptp_clock, @@ -225,6 +233,21 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, mutex_init(&ptp->n_vclocks_mux); init_waitqueue_head(&ptp->tsev_wq); + if (!ptp->info->getcycles64 && !ptp->info->getcyclesx64) { + /* Free running cycle counter not supported, use time. */ + ptp->info->getcycles64 = ptp_getcycles64; + + if (ptp->info->gettimex64) + ptp->info->getcyclesx64 = ptp->info->gettimex64; + + if (ptp->info->getcrosststamp) + ptp->info->getcrosscycles = ptp->info->getcrosststamp; + } else { + ptp->has_cycles = true; + if (!ptp->info->getcycles64 && ptp->info->getcyclesx64) + ptp->info->getcycles64 = ptp_getcycles64; + } + if (ptp->info->do_aux_work) { kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker); ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index); diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h index dba6be477067..ab47c10b3874 100644 --- a/drivers/ptp/ptp_private.h +++ b/drivers/ptp/ptp_private.h @@ -52,6 +52,7 @@ struct ptp_clock { int *vclock_index; struct mutex n_vclocks_mux; /* protect concurrent n_vclocks access */ bool is_virtual_clock; + bool has_cycles; }; #define info_to_vclock(d) container_of((d), struct ptp_vclock, info) @@ -96,6 +97,15 @@ static inline bool ptp_vclock_in_use(struct ptp_clock *ptp) return in_use; } +/* Check if ptp clock shall be free running */ +static inline bool ptp_clock_freerun(struct ptp_clock *ptp) +{ + if (ptp->has_cycles) + return false; + + return ptp_vclock_in_use(ptp); +} + extern struct class *ptp_class; /* diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c index 9233bfedeb17..414a70d32571 100644 --- a/drivers/ptp/ptp_sysfs.c +++ b/drivers/ptp/ptp_sysfs.c @@ -231,10 +231,12 @@ static ssize_t n_vclocks_store(struct device *dev, *(ptp->vclock_index + ptp->n_vclocks - i) = -1; } - if (num == 0) - dev_info(dev, "only physical clock in use now\n"); - else - dev_info(dev, "guarantee physical clock free running\n"); + if (!ptp->has_cycles) { + if (num == 0) + dev_info(dev, "only physical clock in use now\n"); + else + dev_info(dev, "guarantee physical clock free running\n"); + } ptp->n_vclocks = num; mutex_unlock(&ptp->n_vclocks_mux); diff --git a/drivers/ptp/ptp_vclock.c b/drivers/ptp/ptp_vclock.c index cb179a3ea508..3a095eab9cc5 100644 --- a/drivers/ptp/ptp_vclock.c +++ b/drivers/ptp/ptp_vclock.c @@ -68,7 +68,7 @@ static int ptp_vclock_gettimex(struct ptp_clock_info *ptp, int err; u64 ns; - err = pptp->info->gettimex64(pptp->info, &pts, sts); + err = pptp->info->getcyclesx64(pptp->info, &pts, sts); if (err) return err; @@ -104,7 +104,7 @@ static int ptp_vclock_getcrosststamp(struct ptp_clock_info *ptp, int err; u64 ns; - err = pptp->info->getcrosststamp(pptp->info, xtstamp); + err = pptp->info->getcrosscycles(pptp->info, xtstamp); if (err) return err; @@ -143,10 +143,7 @@ static u64 ptp_vclock_read(const struct cyclecounter *cc) struct ptp_clock *ptp = vclock->pclock; struct timespec64 ts = {}; - if (ptp->info->gettimex64) - ptp->info->gettimex64(ptp->info, &ts, NULL); - else - ptp->info->gettime64(ptp->info, &ts); + ptp->info->getcycles64(ptp->info, &ts); return timespec64_to_ns(&ts); } @@ -168,11 +165,11 @@ struct ptp_vclock *ptp_vclock_register(struct ptp_clock *pclock) vclock->pclock = pclock; vclock->info = ptp_vclock_info; - if (pclock->info->gettimex64) + if (pclock->info->getcyclesx64) vclock->info.gettimex64 = ptp_vclock_gettimex; else vclock->info.gettime64 = ptp_vclock_gettime; - if (pclock->info->getcrosststamp) + if (pclock->info->getcrosscycles) vclock->info.getcrosststamp = ptp_vclock_getcrosststamp; vclock->cc = ptp_vclock_cc; diff --git a/include/linux/ptp_clock_kernel.h b/include/linux/ptp_clock_kernel.h index 554454cb8693..3ea7110a9d70 100644 --- a/include/linux/ptp_clock_kernel.h +++ b/include/linux/ptp_clock_kernel.h @@ -108,6 +108,32 @@ struct ptp_system_timestamp { * @settime64: Set the current time on the hardware clock. * parameter ts: Time value to set. * + * @getcycles64: Reads the current free running cycle counter from the hardware + * clock. + * If @getcycles64 and @getcyclesx64 are not supported, then + * @gettime64 or @gettimex64 will be used as default + * implementation. + * parameter ts: Holds the result. + * + * @getcyclesx64: Reads the current free running cycle counter from the + * hardware clock and optionally also the system clock. + * If @getcycles64 and @getcyclesx64 are not supported, then + * @gettimex64 will be used as default implementation if + * available. + * parameter ts: Holds the PHC timestamp. + * parameter sts: If not NULL, it holds a pair of timestamps + * from the system clock. The first reading is made right before + * reading the lowest bits of the PHC timestamp and the second + * reading immediately follows that. + * + * @getcrosscycles: Reads the current free running cycle counter from the + * hardware clock and system clock simultaneously. + * If @getcycles64 and @getcyclesx64 are not supported, then + * @getcrosststamp will be used as default implementation if + * available. + * parameter cts: Contains timestamp (device,system) pair, + * where system time is realtime and monotonic. + * * @enable: Request driver to enable or disable an ancillary feature. * parameter request: Desired resource to enable or disable. * parameter on: Caller passes one to enable or zero to disable. @@ -155,6 +181,11 @@ struct ptp_clock_info { int (*getcrosststamp)(struct ptp_clock_info *ptp, struct system_device_crosststamp *cts); int (*settime64)(struct ptp_clock_info *p, const struct timespec64 *ts); + int (*getcycles64)(struct ptp_clock_info *ptp, struct timespec64 *ts); + int (*getcyclesx64)(struct ptp_clock_info *ptp, struct timespec64 *ts, + struct ptp_system_timestamp *sts); + int (*getcrosscycles)(struct ptp_clock_info *ptp, + struct system_device_crosststamp *cts); int (*enable)(struct ptp_clock_info *ptp, struct ptp_clock_request *request, int on); int (*verify)(struct ptp_clock_info *ptp, unsigned int pin,